linux/arch/mips/kernel/traps.c

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/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1994 - 1999, 2000, 01, 06 Ralf Baechle
* Copyright (C) 1995, 1996 Paul M. Antoine
* Copyright (C) 1998 Ulf Carlsson
* Copyright (C) 1999 Silicon Graphics, Inc.
* Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
* Copyright (C) 2002, 2003, 2004, 2005, 2007 Maciej W. Rozycki
* Copyright (C) 2000, 2001, 2012 MIPS Technologies, Inc. All rights reserved.
* Copyright (C) 2014, Imagination Technologies Ltd.
*/
#include <linux/bitops.h>
#include <linux/bug.h>
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
#include <linux/compiler.h>
#include <linux/context_tracking.h>
#include <linux/cpu_pm.h>
#include <linux/kexec.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/extable.h>
#include <linux/mm.h>
sched/headers: Move task->mm handling methods to <linux/sched/mm.h> Move the following task->mm helper APIs into a new header file, <linux/sched/mm.h>, to further reduce the size and complexity of <linux/sched.h>. Here are how the APIs are used in various kernel files: # mm_alloc(): arch/arm/mach-rpc/ecard.c fs/exec.c include/linux/sched/mm.h kernel/fork.c # __mmdrop(): arch/arc/include/asm/mmu_context.h include/linux/sched/mm.h kernel/fork.c # mmdrop(): arch/arm/mach-rpc/ecard.c arch/m68k/sun3/mmu_emu.c arch/x86/mm/tlb.c drivers/gpu/drm/amd/amdkfd/kfd_process.c drivers/gpu/drm/i915/i915_gem_userptr.c drivers/infiniband/hw/hfi1/file_ops.c drivers/vfio/vfio_iommu_spapr_tce.c fs/exec.c fs/proc/base.c fs/proc/task_mmu.c fs/proc/task_nommu.c fs/userfaultfd.c include/linux/mmu_notifier.h include/linux/sched/mm.h kernel/fork.c kernel/futex.c kernel/sched/core.c mm/khugepaged.c mm/ksm.c mm/mmu_context.c mm/mmu_notifier.c mm/oom_kill.c virt/kvm/kvm_main.c # mmdrop_async_fn(): include/linux/sched/mm.h # mmdrop_async(): include/linux/sched/mm.h kernel/fork.c # mmget_not_zero(): fs/userfaultfd.c include/linux/sched/mm.h mm/oom_kill.c # mmput(): arch/arc/include/asm/mmu_context.h arch/arc/kernel/troubleshoot.c arch/frv/mm/mmu-context.c arch/powerpc/platforms/cell/spufs/context.c arch/sparc/include/asm/mmu_context_32.h drivers/android/binder.c drivers/gpu/drm/etnaviv/etnaviv_gem.c drivers/gpu/drm/i915/i915_gem_userptr.c drivers/infiniband/core/umem.c drivers/infiniband/core/umem_odp.c drivers/infiniband/core/uverbs_main.c drivers/infiniband/hw/mlx4/main.c drivers/infiniband/hw/mlx5/main.c drivers/infiniband/hw/usnic/usnic_uiom.c drivers/iommu/amd_iommu_v2.c drivers/iommu/intel-svm.c drivers/lguest/lguest_user.c drivers/misc/cxl/fault.c drivers/misc/mic/scif/scif_rma.c drivers/oprofile/buffer_sync.c drivers/vfio/vfio_iommu_type1.c drivers/vhost/vhost.c drivers/xen/gntdev.c fs/exec.c fs/proc/array.c fs/proc/base.c fs/proc/task_mmu.c fs/proc/task_nommu.c fs/userfaultfd.c include/linux/sched/mm.h kernel/cpuset.c kernel/events/core.c kernel/events/uprobes.c kernel/exit.c kernel/fork.c kernel/ptrace.c kernel/sys.c kernel/trace/trace_output.c kernel/tsacct.c mm/memcontrol.c mm/memory.c mm/mempolicy.c mm/migrate.c mm/mmu_notifier.c mm/nommu.c mm/oom_kill.c mm/process_vm_access.c mm/rmap.c mm/swapfile.c mm/util.c virt/kvm/async_pf.c # mmput_async(): include/linux/sched/mm.h kernel/fork.c mm/oom_kill.c # get_task_mm(): arch/arc/kernel/troubleshoot.c arch/powerpc/platforms/cell/spufs/context.c drivers/android/binder.c drivers/gpu/drm/etnaviv/etnaviv_gem.c drivers/infiniband/core/umem.c drivers/infiniband/core/umem_odp.c drivers/infiniband/hw/mlx4/main.c drivers/infiniband/hw/mlx5/main.c drivers/infiniband/hw/usnic/usnic_uiom.c drivers/iommu/amd_iommu_v2.c drivers/iommu/intel-svm.c drivers/lguest/lguest_user.c drivers/misc/cxl/fault.c drivers/misc/mic/scif/scif_rma.c drivers/oprofile/buffer_sync.c drivers/vfio/vfio_iommu_type1.c drivers/vhost/vhost.c drivers/xen/gntdev.c fs/proc/array.c fs/proc/base.c fs/proc/task_mmu.c include/linux/sched/mm.h kernel/cpuset.c kernel/events/core.c kernel/exit.c kernel/fork.c kernel/ptrace.c kernel/sys.c kernel/trace/trace_output.c kernel/tsacct.c mm/memcontrol.c mm/memory.c mm/mempolicy.c mm/migrate.c mm/mmu_notifier.c mm/nommu.c mm/util.c # mm_access(): fs/proc/base.c include/linux/sched/mm.h kernel/fork.c mm/process_vm_access.c # mm_release(): arch/arc/include/asm/mmu_context.h fs/exec.c include/linux/sched/mm.h include/uapi/linux/sched.h kernel/exit.c kernel/fork.c Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-01 18:08:20 +00:00
#include <linux/sched/mm.h>
#include <linux/sched/debug.h>
#include <linux/smp.h>
#include <linux/spinlock.h>
#include <linux/kallsyms.h>
#include <linux/memblock.h>
#include <linux/interrupt.h>
#include <linux/ptrace.h>
#include <linux/kgdb.h>
#include <linux/kdebug.h>
#include <linux/kprobes.h>
#include <linux/notifier.h>
#include <linux/kdb.h>
#include <linux/irq.h>
#include <linux/perf_event.h>
#include <asm/addrspace.h>
#include <asm/bootinfo.h>
#include <asm/branch.h>
#include <asm/break.h>
#include <asm/cop2.h>
#include <asm/cpu.h>
#include <asm/cpu-type.h>
#include <asm/dsp.h>
#include <asm/fpu.h>
#include <asm/fpu_emulator.h>
#include <asm/idle.h>
#include <asm/isa-rev.h>
#include <asm/mips-cps.h>
#include <asm/mips-r2-to-r6-emul.h>
#include <asm/mipsregs.h>
#include <asm/mipsmtregs.h>
#include <asm/module.h>
#include <asm/msa.h>
#include <asm/ptrace.h>
#include <asm/sections.h>
#include <asm/siginfo.h>
#include <asm/tlbdebug.h>
#include <asm/traps.h>
#include <linux/uaccess.h>
#include <asm/watch.h>
#include <asm/mmu_context.h>
#include <asm/types.h>
#include <asm/stacktrace.h>
MIPS: Consistently declare TLB functions Since at least the beginning of the git era we've declared our TLB exception handling functions inconsistently. They're actually functions, but we declare them as arrays of u32 where each u32 is an encoded instruction. This has always been the case for arch/mips/mm/tlbex.c, and has also been true for arch/mips/kernel/traps.c since commit 86a1708a9d54 ("MIPS: Make tlb exception handler definitions and declarations match.") which aimed for consistency but did so by consistently making the our C code inconsistent with our assembly. This is all usually harmless, but when using GCC 7 or newer to build a kernel targeting microMIPS (ie. CONFIG_CPU_MICROMIPS=y) it becomes problematic. With microMIPS bit 0 of the program counter indicates the ISA mode. When bit 0 is zero instructions are decoded using the standard MIPS32 or MIPS64 ISA. When bit 0 is one instructions are decoded using microMIPS. This means that function pointers become odd - their least significant bit is one for microMIPS code. We work around this in cases where we need to access code using loads & stores with our msk_isa16_mode() macro which simply clears bit 0 of the value it is given: #define msk_isa16_mode(x) ((x) & ~0x1) For example we do this for our TLB load handler in build_r4000_tlb_load_handler(): u32 *p = (u32 *)msk_isa16_mode((ulong)handle_tlbl); We then write code to p, expecting it to be suitably aligned (our LEAF macro aligns functions on 4 byte boundaries, so (ulong)handle_tlbl will give a value one greater than a multiple of 4 - ie. the start of a function on a 4 byte boundary, with the ISA mode bit 0 set). This worked fine up to GCC 6, but GCC 7 & onwards is smart enough to presume that handle_tlbl which we declared as an array of u32s must be aligned sufficiently that bit 0 of its address will never be set, and as a result optimize out msk_isa16_mode(). This leads to p having an address with bit 0 set, and when we go on to attempt to store code at that address we take an address error exception due to the unaligned memory access. This leads to an exception prior to the kernel having configured its own exception handlers, so we jump to whatever handlers the bootloader configured. In the case of QEMU this results in a silent hang, since it has no useful general exception vector. Fix this by consistently declaring our TLB-related functions as functions. For handle_tlbl(), handle_tlbs() & handle_tlbm() we do this in asm/tlbex.h & we make use of the existing declaration of tlbmiss_handler_setup_pgd() in asm/mmu_context.h. Our TLB handler generation code in arch/mips/mm/tlbex.c is adjusted to deal with these definitions, in most cases simply by casting the function pointers to u32 pointers. This allows us to include asm/mmu_context.h in arch/mips/mm/tlbex.c to get the definitions of tlbmiss_handler_setup_pgd & pgd_current, removing some needless duplication. Consistently using msk_isa16_mode() on function pointers means we no longer need the tlbmiss_handler_setup_pgd_start symbol so that is removed entirely. Now that we're declaring our functions as functions GCC stops optimizing out msk_isa16_mode() & a microMIPS kernel built with either GCC 7.3.0 or 8.1.0 boots successfully. Signed-off-by: Paul Burton <paul.burton@mips.com>
2018-08-10 23:03:31 +00:00
#include <asm/tlbex.h>
#include <asm/uasm.h>
MIPS: emulate CPUCFG instruction on older Loongson64 cores CPUCFG is the instruction for querying processor characteristics on newer Loongson processors, much like CPUID of x86. Since the instruction is supposedly designed to provide a unified way to do feature detection (without having to, for example, parse /proc/cpuinfo which is too heavyweight), it is important to provide compatibility for older cores without native support. Fortunately, most of the fields can be synthesized without changes to semantics. Performance is not really big a concern, because feature detection logic is not expected to be invoked very often in typical userland applications. The instruction can't be emulated on LOONGSON_2EF cores, according to FlyGoat's experiments. Because the LWC2 opcode is assigned to other valid instructions on 2E and 2F, no RI exception is raised for us to intercept. So compatibility is only extended back furthest to Loongson-3A1000. Loongson-2K is covered too, as it is basically a remix of various blocks from the 3A/3B models from a kernel perspective. This is lightly based on Loongson's work on their Linux 3.10 fork, for being the authority on the right feature flags to fill in, where things aren't otherwise discoverable. Signed-off-by: WANG Xuerui <git@xen0n.name> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Huacai Chen <chenhc@lemote.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2020-05-23 13:37:01 +00:00
#include <asm/mach-loongson64/cpucfg-emul.h>
#include "access-helper.h"
extern void check_wait(void);
extern asmlinkage void rollback_handle_int(void);
extern asmlinkage void handle_int(void);
extern asmlinkage void handle_adel(void);
extern asmlinkage void handle_ades(void);
extern asmlinkage void handle_ibe(void);
extern asmlinkage void handle_dbe(void);
extern asmlinkage void handle_sys(void);
extern asmlinkage void handle_bp(void);
extern asmlinkage void handle_ri(void);
extern asmlinkage void handle_ri_rdhwr_tlbp(void);
extern asmlinkage void handle_ri_rdhwr(void);
extern asmlinkage void handle_cpu(void);
extern asmlinkage void handle_ov(void);
extern asmlinkage void handle_tr(void);
extern asmlinkage void handle_msa_fpe(void);
extern asmlinkage void handle_fpe(void);
extern asmlinkage void handle_ftlb(void);
MIPS: handle Loongson-specific GSExc exception Newer Loongson cores (Loongson-3A R2 and newer) use the implementation-dependent ExcCode 16 to signal Loongson-specific exceptions. The extended cause is put in the non-standard CP0.Diag1 register which is CP0 Register 22 Select 1, called GSCause in Loongson manuals. Inside is an exception code bitfield called GSExcCode, only codes 0 to 6 inclusive are documented (so far, in the Loongson 3A3000 User Manual, Volume 2). During experiments, it was found that some undocumented unprivileged instructions can trigger the also-undocumented GSExcCode 8 on Loongson 3A4000. Processor state is not corrupted, but we cannot continue without further knowledge, and Loongson is not providing that information as of this writing. So we send SIGILL on seeing this exception code to thwart easy local DoS attacks. Other exception codes are made fatal, partly because of insufficient knowledge, also partly because they are not as easily reproduced. None of them are encountered in the wild with upstream kernels and userspace so far. Some older cores (Loongson-3A1000 and Loongson-3B1500) have ExcCode 16 too, but the semantic is equivalent to GSExcCode 0. Because the respective manuals did not mention the CP0.Diag1 register or its read behavior, these cores are not covered in this patch, as MFC0 from non-existent CP0 registers is UNDEFINED according to the MIPS architecture spec. Reviewed-by: Huacai Chen <chenhc@lemote.com> Signed-off-by: WANG Xuerui <git@xen0n.name> Cc: Huacai Chen <chenhc@lemote.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2020-07-29 13:14:17 +00:00
extern asmlinkage void handle_gsexc(void);
extern asmlinkage void handle_msa(void);
extern asmlinkage void handle_mdmx(void);
extern asmlinkage void handle_watch(void);
extern asmlinkage void handle_mt(void);
extern asmlinkage void handle_dsp(void);
extern asmlinkage void handle_mcheck(void);
extern asmlinkage void handle_reserved(void);
extern void tlb_do_page_fault_0(void);
void (*board_be_init)(void);
static int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
void (*board_nmi_handler_setup)(void);
void (*board_ejtag_handler_setup)(void);
void (*board_bind_eic_interrupt)(int irq, int regset);
void (*board_ebase_setup)(void);
MIPS: Delete __cpuinit/__CPUINIT usage from MIPS code commit 3747069b25e419f6b51395f48127e9812abc3596 upstream. The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. Note that some harmless section mismatch warnings may result, since notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c) and are flagged as __cpuinit -- so if we remove the __cpuinit from the arch specific callers, we will also get section mismatch warnings. As an intermediate step, we intend to turn the linux/init.h cpuinit related content into no-ops as early as possible, since that will get rid of these warnings. In any case, they are temporary and harmless. Here, we remove all the MIPS __cpuinit from C code and __CPUINIT from asm files. MIPS is interesting in this respect, because there are also uasm users hiding behind their own renamed versions of the __cpuinit macros. [1] https://lkml.org/lkml/2013/5/20/589 [ralf@linux-mips.org: Folded in Paul's followup fix.] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/5494/ Patchwork: https://patchwork.linux-mips.org/patch/5495/ Patchwork: https://patchwork.linux-mips.org/patch/5509/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-06-18 13:38:59 +00:00
void(*board_cache_error_setup)(void);
void mips_set_be_handler(int (*handler)(struct pt_regs *regs, int is_fixup))
{
board_be_handler = handler;
}
EXPORT_SYMBOL_GPL(mips_set_be_handler);
static void show_raw_backtrace(unsigned long reg29, const char *loglvl,
bool user)
{
unsigned long *sp = (unsigned long *)(reg29 & ~3);
unsigned long addr;
printk("%sCall Trace:", loglvl);
#ifdef CONFIG_KALLSYMS
printk("%s\n", loglvl);
#endif
while (!kstack_end(sp)) {
if (__get_addr(&addr, sp++, user)) {
printk("%s (Bad stack address)", loglvl);
break;
}
if (__kernel_text_address(addr))
print_ip_sym(loglvl, addr);
}
printk("%s\n", loglvl);
}
#ifdef CONFIG_KALLSYMS
int raw_show_trace;
static int __init set_raw_show_trace(char *str)
{
raw_show_trace = 1;
return 1;
}
__setup("raw_show_trace", set_raw_show_trace);
#endif
static void show_backtrace(struct task_struct *task, const struct pt_regs *regs,
const char *loglvl, bool user)
{
unsigned long sp = regs->regs[29];
unsigned long ra = regs->regs[31];
unsigned long pc = regs->cp0_epc;
if (!task)
task = current;
if (raw_show_trace || user_mode(regs) || !__kernel_text_address(pc)) {
show_raw_backtrace(sp, loglvl, user);
return;
}
printk("%sCall Trace:\n", loglvl);
do {
print_ip_sym(loglvl, pc);
pc = unwind_stack(task, &sp, pc, &ra);
} while (pc);
pr_cont("\n");
}
/*
* This routine abuses get_user()/put_user() to reference pointers
* with at least a bit of error checking ...
*/
static void show_stacktrace(struct task_struct *task,
const struct pt_regs *regs, const char *loglvl, bool user)
{
const int field = 2 * sizeof(unsigned long);
unsigned long stackdata;
int i;
unsigned long *sp = (unsigned long *)regs->regs[29];
printk("%sStack :", loglvl);
i = 0;
while ((unsigned long) sp & (PAGE_SIZE - 1)) {
if (i && ((i % (64 / field)) == 0)) {
pr_cont("\n");
printk("%s ", loglvl);
}
if (i > 39) {
pr_cont(" ...");
break;
}
if (__get_addr(&stackdata, sp++, user)) {
pr_cont(" (Bad stack address)");
break;
}
pr_cont(" %0*lx", field, stackdata);
i++;
}
pr_cont("\n");
show_backtrace(task, regs, loglvl, user);
}
void show_stack(struct task_struct *task, unsigned long *sp, const char *loglvl)
{
struct pt_regs regs;
regs.cp0_status = KSU_KERNEL;
if (sp) {
regs.regs[29] = (unsigned long)sp;
regs.regs[31] = 0;
regs.cp0_epc = 0;
} else {
if (task && task != current) {
regs.regs[29] = task->thread.reg29;
regs.regs[31] = 0;
regs.cp0_epc = task->thread.reg31;
} else {
prepare_frametrace(&regs);
}
}
show_stacktrace(task, &regs, loglvl, false);
}
static void show_code(void *pc, bool user)
{
long i;
unsigned short *pc16 = NULL;
printk("Code:");
if ((unsigned long)pc & 1)
pc16 = (u16 *)((unsigned long)pc & ~1);
for(i = -3 ; i < 6 ; i++) {
if (pc16) {
u16 insn16;
if (__get_inst16(&insn16, pc16 + i, user))
goto bad_address;
pr_cont("%c%04x%c", (i?' ':'<'), insn16, (i?' ':'>'));
} else {
u32 insn32;
if (__get_inst32(&insn32, (u32 *)pc + i, user))
goto bad_address;
pr_cont("%c%08x%c", (i?' ':'<'), insn32, (i?' ':'>'));
}
}
pr_cont("\n");
return;
bad_address:
pr_cont(" (Bad address in epc)\n\n");
}
static void __show_regs(const struct pt_regs *regs)
{
const int field = 2 * sizeof(unsigned long);
unsigned int cause = regs->cp0_cause;
unsigned int exccode;
int i;
dump_stack: unify debug information printed by show_regs() show_regs() is inherently arch-dependent but it does make sense to print generic debug information and some archs already do albeit in slightly different forms. This patch introduces a generic function to print debug information from show_regs() so that different archs print out the same information and it's much easier to modify what's printed. show_regs_print_info() prints out the same debug info as dump_stack() does plus task and thread_info pointers. * Archs which didn't print debug info now do. alpha, arc, blackfin, c6x, cris, frv, h8300, hexagon, ia64, m32r, metag, microblaze, mn10300, openrisc, parisc, score, sh64, sparc, um, xtensa * Already prints debug info. Replaced with show_regs_print_info(). The printed information is superset of what used to be there. arm, arm64, avr32, mips, powerpc, sh32, tile, unicore32, x86 * s390 is special in that it used to print arch-specific information along with generic debug info. Heiko and Martin think that the arch-specific extra isn't worth keeping s390 specfic implementation. Converted to use the generic version. Note that now all archs print the debug info before actual register dumps. An example BUG() dump follows. kernel BUG at /work/os/work/kernel/workqueue.c:4841! invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #7 Hardware name: empty empty/S3992, BIOS 080011 10/26/2007 task: ffff88007c85e040 ti: ffff88007c860000 task.ti: ffff88007c860000 RIP: 0010:[<ffffffff8234a07e>] [<ffffffff8234a07e>] init_workqueues+0x4/0x6 RSP: 0000:ffff88007c861ec8 EFLAGS: 00010246 RAX: ffff88007c861fd8 RBX: ffffffff824466a8 RCX: 0000000000000001 RDX: 0000000000000046 RSI: 0000000000000001 RDI: ffffffff8234a07a RBP: ffff88007c861ec8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8234a07a R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: ffff88015f7ff000 CR3: 00000000021f1000 CR4: 00000000000007f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Stack: ffff88007c861ef8 ffffffff81000312 ffffffff824466a8 ffff88007c85e650 0000000000000003 0000000000000000 ffff88007c861f38 ffffffff82335e5d ffff88007c862080 ffffffff8223d8c0 ffff88007c862080 ffffffff81c47760 Call Trace: [<ffffffff81000312>] do_one_initcall+0x122/0x170 [<ffffffff82335e5d>] kernel_init_freeable+0x9b/0x1c8 [<ffffffff81c47760>] ? rest_init+0x140/0x140 [<ffffffff81c4776e>] kernel_init+0xe/0xf0 [<ffffffff81c6be9c>] ret_from_fork+0x7c/0xb0 [<ffffffff81c47760>] ? rest_init+0x140/0x140 ... v2: Typo fix in x86-32. v3: CPU number dropped from show_regs_print_info() as dump_stack_print_info() has been updated to print it. s390 specific implementation dropped as requested by s390 maintainers. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Sam Ravnborg <sam@ravnborg.org> Acked-by: Chris Metcalf <cmetcalf@tilera.com> [tile bits] Acked-by: Richard Kuo <rkuo@codeaurora.org> [hexagon bits] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 22:27:17 +00:00
show_regs_print_info(KERN_DEFAULT);
/*
* Saved main processor registers
*/
for (i = 0; i < 32; ) {
if ((i % 4) == 0)
printk("$%2d :", i);
if (i == 0)
pr_cont(" %0*lx", field, 0UL);
else if (i == 26 || i == 27)
pr_cont(" %*s", field, "");
else
pr_cont(" %0*lx", field, regs->regs[i]);
i++;
if ((i % 4) == 0)
pr_cont("\n");
}
#ifdef CONFIG_CPU_HAS_SMARTMIPS
printk("Acx : %0*lx\n", field, regs->acx);
#endif
if (MIPS_ISA_REV < 6) {
printk("Hi : %0*lx\n", field, regs->hi);
printk("Lo : %0*lx\n", field, regs->lo);
}
/*
* Saved cp0 registers
*/
printk("epc : %0*lx %pS\n", field, regs->cp0_epc,
(void *) regs->cp0_epc);
printk("ra : %0*lx %pS\n", field, regs->regs[31],
(void *) regs->regs[31]);
printk("Status: %08x ", (uint32_t) regs->cp0_status);
if (cpu_has_3kex) {
if (regs->cp0_status & ST0_KUO)
pr_cont("KUo ");
if (regs->cp0_status & ST0_IEO)
pr_cont("IEo ");
if (regs->cp0_status & ST0_KUP)
pr_cont("KUp ");
if (regs->cp0_status & ST0_IEP)
pr_cont("IEp ");
if (regs->cp0_status & ST0_KUC)
pr_cont("KUc ");
if (regs->cp0_status & ST0_IEC)
pr_cont("IEc ");
} else if (cpu_has_4kex) {
if (regs->cp0_status & ST0_KX)
pr_cont("KX ");
if (regs->cp0_status & ST0_SX)
pr_cont("SX ");
if (regs->cp0_status & ST0_UX)
pr_cont("UX ");
switch (regs->cp0_status & ST0_KSU) {
case KSU_USER:
pr_cont("USER ");
break;
case KSU_SUPERVISOR:
pr_cont("SUPERVISOR ");
break;
case KSU_KERNEL:
pr_cont("KERNEL ");
break;
default:
pr_cont("BAD_MODE ");
break;
}
if (regs->cp0_status & ST0_ERL)
pr_cont("ERL ");
if (regs->cp0_status & ST0_EXL)
pr_cont("EXL ");
if (regs->cp0_status & ST0_IE)
pr_cont("IE ");
}
pr_cont("\n");
exccode = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
printk("Cause : %08x (ExcCode %02x)\n", cause, exccode);
if (1 <= exccode && exccode <= 5)
printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr);
printk("PrId : %08x (%s)\n", read_c0_prid(),
cpu_name_string());
}
/*
* FIXME: really the generic show_regs should take a const pointer argument.
*/
void show_regs(struct pt_regs *regs)
{
__show_regs(regs);
MIPS: Call dump_stack() from show_regs() The generic nmi_cpu_backtrace() function calls show_regs() when a struct pt_regs is available, and dump_stack() otherwise. If we were to make use of the generic nmi_cpu_backtrace() with MIPS' current implementation of show_regs() this would mean that we see only register data with no accompanying stack information, in contrast with our current implementation which calls dump_stack() regardless of whether register state is available. In preparation for making use of the generic nmi_cpu_backtrace() to implement arch_trigger_cpumask_backtrace(), have our implementation of show_regs() call dump_stack() and drop the explicit dump_stack() call in arch_dump_stack() which is invoked by arch_trigger_cpumask_backtrace(). This will allow the output we produce to remain the same after a later patch switches to using nmi_cpu_backtrace(). It may mean that we produce extra stack output in other uses of show_regs(), but this: 1) Seems harmless. 2) Is good for consistency between arch_trigger_cpumask_backtrace() and other users of show_regs(). 3) Matches the behaviour of the ARM & PowerPC architectures. Marked for stable back to v4.9 as a prerequisite of the following patch "MIPS: Call dump_stack() from show_regs()". Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/19596/ Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Huacai Chen <chenhc@lemote.com> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org # v4.9+
2018-06-22 17:55:45 +00:00
dump_stack();
}
void show_registers(struct pt_regs *regs)
{
const int field = 2 * sizeof(unsigned long);
__show_regs(regs);
print_modules();
printk("Process %s (pid: %d, threadinfo=%p, task=%p, tls=%0*lx)\n",
current->comm, current->pid, current_thread_info(), current,
field, current_thread_info()->tp_value);
if (cpu_has_userlocal) {
unsigned long tls;
tls = read_c0_userlocal();
if (tls != current_thread_info()->tp_value)
printk("*HwTLS: %0*lx\n", field, tls);
}
show_stacktrace(current, regs, KERN_DEFAULT, user_mode(regs));
show_code((void *)regs->cp0_epc, user_mode(regs));
printk("\n");
}
static DEFINE_RAW_SPINLOCK(die_lock);
void __noreturn die(const char *str, struct pt_regs *regs)
{
static int die_counter;
int sig = SIGSEGV;
oops_enter();
if (notify_die(DIE_OOPS, str, regs, 0, current->thread.trap_nr,
SIGSEGV) == NOTIFY_STOP)
sig = 0;
console_verbose();
raw_spin_lock_irq(&die_lock);
bust_spinlocks(1);
printk("%s[#%d]:\n", str, ++die_counter);
show_registers(regs);
add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
raw_spin_unlock_irq(&die_lock);
oops_exit();
if (in_interrupt())
panic("Fatal exception in interrupt");
if (panic_on_oops)
panic("Fatal exception");
if (regs && kexec_should_crash(current))
crash_kexec(regs);
make_task_dead(sig);
}
extern struct exception_table_entry __start___dbe_table[];
extern struct exception_table_entry __stop___dbe_table[];
__asm__(
" .section __dbe_table, \"a\"\n"
" .previous \n");
/* Given an address, look for it in the exception tables. */
static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
{
const struct exception_table_entry *e;
e = search_extable(__start___dbe_table,
__stop___dbe_table - __start___dbe_table, addr);
if (!e)
e = search_module_dbetables(addr);
return e;
}
asmlinkage void do_be(struct pt_regs *regs)
{
const int field = 2 * sizeof(unsigned long);
const struct exception_table_entry *fixup = NULL;
int data = regs->cp0_cause & 4;
int action = MIPS_BE_FATAL;
enum ctx_state prev_state;
prev_state = exception_enter();
/* XXX For now. Fixme, this searches the wrong table ... */
if (data && !user_mode(regs))
fixup = search_dbe_tables(exception_epc(regs));
if (fixup)
action = MIPS_BE_FIXUP;
if (board_be_handler)
action = board_be_handler(regs, fixup != NULL);
else
mips_cm_error_report();
switch (action) {
case MIPS_BE_DISCARD:
goto out;
case MIPS_BE_FIXUP:
if (fixup) {
regs->cp0_epc = fixup->nextinsn;
goto out;
}
break;
default:
break;
}
/*
* Assume it would be too dangerous to continue ...
*/
printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
data ? "Data" : "Instruction",
field, regs->cp0_epc, field, regs->regs[31]);
if (notify_die(DIE_OOPS, "bus error", regs, 0, current->thread.trap_nr,
SIGBUS) == NOTIFY_STOP)
goto out;
die_if_kernel("Oops", regs);
force_sig(SIGBUS);
out:
exception_exit(prev_state);
}
/*
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
* ll/sc, rdhwr, sync emulation
*/
#define OPCODE 0xfc000000
#define BASE 0x03e00000
#define RT 0x001f0000
#define OFFSET 0x0000ffff
#define LL 0xc0000000
#define SC 0xe0000000
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
#define SPEC0 0x00000000
#define SPEC3 0x7c000000
#define RD 0x0000f800
#define FUNC 0x0000003f
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
#define SYNC 0x0000000f
#define RDHWR 0x0000003b
/* microMIPS definitions */
#define MM_POOL32A_FUNC 0xfc00ffff
#define MM_RDHWR 0x00006b3c
#define MM_RS 0x001f0000
#define MM_RT 0x03e00000
/*
* The ll_bit is cleared by r*_switch.S
*/
unsigned int ll_bit;
struct task_struct *ll_task;
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
static inline int simulate_ll(struct pt_regs *regs, unsigned int opcode)
{
unsigned long value, __user *vaddr;
long offset;
/*
* analyse the ll instruction that just caused a ri exception
* and put the referenced address to addr.
*/
/* sign extend offset */
offset = opcode & OFFSET;
offset <<= 16;
offset >>= 16;
vaddr = (unsigned long __user *)
((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
if ((unsigned long)vaddr & 3)
return SIGBUS;
if (get_user(value, vaddr))
return SIGSEGV;
preempt_disable();
if (ll_task == NULL || ll_task == current) {
ll_bit = 1;
} else {
ll_bit = 0;
}
ll_task = current;
preempt_enable();
regs->regs[(opcode & RT) >> 16] = value;
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
return 0;
}
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
static inline int simulate_sc(struct pt_regs *regs, unsigned int opcode)
{
unsigned long __user *vaddr;
unsigned long reg;
long offset;
/*
* analyse the sc instruction that just caused a ri exception
* and put the referenced address to addr.
*/
/* sign extend offset */
offset = opcode & OFFSET;
offset <<= 16;
offset >>= 16;
vaddr = (unsigned long __user *)
((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
reg = (opcode & RT) >> 16;
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
if ((unsigned long)vaddr & 3)
return SIGBUS;
preempt_disable();
if (ll_bit == 0 || ll_task != current) {
regs->regs[reg] = 0;
preempt_enable();
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
return 0;
}
preempt_enable();
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
if (put_user(regs->regs[reg], vaddr))
return SIGSEGV;
regs->regs[reg] = 1;
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
return 0;
}
/*
* ll uses the opcode of lwc0 and sc uses the opcode of swc0. That is both
* opcodes are supposed to result in coprocessor unusable exceptions if
* executed on ll/sc-less processors. That's the theory. In practice a
* few processors such as NEC's VR4100 throw reserved instruction exceptions
* instead, so we're doing the emulation thing in both exception handlers.
*/
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
static int simulate_llsc(struct pt_regs *regs, unsigned int opcode)
{
if ((opcode & OPCODE) == LL) {
perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
1, regs, 0);
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
return simulate_ll(regs, opcode);
}
if ((opcode & OPCODE) == SC) {
perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
1, regs, 0);
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
return simulate_sc(regs, opcode);
}
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
return -1; /* Must be something else ... */
}
/*
* Simulate trapping 'rdhwr' instructions to provide user accessible
* registers not implemented in hardware.
*/
static int simulate_rdhwr(struct pt_regs *regs, int rd, int rt)
{
struct thread_info *ti = task_thread_info(current);
perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
1, regs, 0);
switch (rd) {
case MIPS_HWR_CPUNUM: /* CPU number */
regs->regs[rt] = smp_processor_id();
return 0;
case MIPS_HWR_SYNCISTEP: /* SYNCI length */
regs->regs[rt] = min(current_cpu_data.dcache.linesz,
current_cpu_data.icache.linesz);
return 0;
case MIPS_HWR_CC: /* Read count register */
regs->regs[rt] = read_c0_count();
return 0;
case MIPS_HWR_CCRES: /* Count register resolution */
switch (current_cpu_type()) {
case CPU_20KC:
case CPU_25KF:
regs->regs[rt] = 1;
break;
default:
regs->regs[rt] = 2;
}
return 0;
case MIPS_HWR_ULR: /* Read UserLocal register */
regs->regs[rt] = ti->tp_value;
return 0;
default:
return -1;
}
}
static int simulate_rdhwr_normal(struct pt_regs *regs, unsigned int opcode)
{
if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
int rd = (opcode & RD) >> 11;
int rt = (opcode & RT) >> 16;
simulate_rdhwr(regs, rd, rt);
return 0;
}
/* Not ours. */
return -1;
}
static int simulate_rdhwr_mm(struct pt_regs *regs, unsigned int opcode)
{
if ((opcode & MM_POOL32A_FUNC) == MM_RDHWR) {
int rd = (opcode & MM_RS) >> 16;
int rt = (opcode & MM_RT) >> 21;
simulate_rdhwr(regs, rd, rt);
return 0;
}
/* Not ours. */
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
return -1;
}
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
static int simulate_sync(struct pt_regs *regs, unsigned int opcode)
{
if ((opcode & OPCODE) == SPEC0 && (opcode & FUNC) == SYNC) {
perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
1, regs, 0);
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
return 0;
}
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
return -1; /* Must be something else ... */
}
MIPS: emulate CPUCFG instruction on older Loongson64 cores CPUCFG is the instruction for querying processor characteristics on newer Loongson processors, much like CPUID of x86. Since the instruction is supposedly designed to provide a unified way to do feature detection (without having to, for example, parse /proc/cpuinfo which is too heavyweight), it is important to provide compatibility for older cores without native support. Fortunately, most of the fields can be synthesized without changes to semantics. Performance is not really big a concern, because feature detection logic is not expected to be invoked very often in typical userland applications. The instruction can't be emulated on LOONGSON_2EF cores, according to FlyGoat's experiments. Because the LWC2 opcode is assigned to other valid instructions on 2E and 2F, no RI exception is raised for us to intercept. So compatibility is only extended back furthest to Loongson-3A1000. Loongson-2K is covered too, as it is basically a remix of various blocks from the 3A/3B models from a kernel perspective. This is lightly based on Loongson's work on their Linux 3.10 fork, for being the authority on the right feature flags to fill in, where things aren't otherwise discoverable. Signed-off-by: WANG Xuerui <git@xen0n.name> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Huacai Chen <chenhc@lemote.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2020-05-23 13:37:01 +00:00
/*
* Loongson-3 CSR instructions emulation
*/
#ifdef CONFIG_CPU_LOONGSON3_CPUCFG_EMULATION
#define LWC2 0xc8000000
#define RS BASE
#define CSR_OPCODE2 0x00000118
#define CSR_OPCODE2_MASK 0x000007ff
#define CSR_FUNC_MASK RT
#define CSR_FUNC_CPUCFG 0x8
static int simulate_loongson3_cpucfg(struct pt_regs *regs,
unsigned int opcode)
{
int op = opcode & OPCODE;
int op2 = opcode & CSR_OPCODE2_MASK;
int csr_func = (opcode & CSR_FUNC_MASK) >> 16;
if (op == LWC2 && op2 == CSR_OPCODE2 && csr_func == CSR_FUNC_CPUCFG) {
int rd = (opcode & RD) >> 11;
int rs = (opcode & RS) >> 21;
__u64 sel = regs->regs[rs];
perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);
/* Do not emulate on unsupported core models. */
MIPS: Do not use smp_processor_id() in preemptible code Use preempt_disable() to fix the following bug under CONFIG_DEBUG_PREEMPT. [ 21.915305] BUG: using smp_processor_id() in preemptible [00000000] code: qemu-system-mip/1056 [ 21.923996] caller is do_ri+0x1d4/0x690 [ 21.927921] CPU: 0 PID: 1056 Comm: qemu-system-mip Not tainted 5.8.0-rc2 #3 [ 21.934913] Stack : 0000000000000001 ffffffff81370000 ffffffff8071cd60 a80f926d5ac95694 [ 21.942984] a80f926d5ac95694 0000000000000000 98000007f0043c88 ffffffff80f2fe40 [ 21.951054] 0000000000000000 0000000000000000 0000000000000001 0000000000000000 [ 21.959123] ffffffff802d60cc 98000007f0043dd8 ffffffff81f4b1e8 ffffffff81f60000 [ 21.967192] ffffffff81f60000 ffffffff80fe0000 ffff000000000000 0000000000000000 [ 21.975261] fffffffff500cce1 0000000000000001 0000000000000002 0000000000000000 [ 21.983331] ffffffff80fe1a40 0000000000000006 ffffffff8077f940 0000000000000000 [ 21.991401] ffffffff81460000 98000007f0040000 98000007f0043c80 000000fffba8cf20 [ 21.999471] ffffffff8071cd60 0000000000000000 0000000000000000 0000000000000000 [ 22.007541] 0000000000000000 0000000000000000 ffffffff80212ab4 a80f926d5ac95694 [ 22.015610] ... [ 22.018086] Call Trace: [ 22.020562] [<ffffffff80212ab4>] show_stack+0xa4/0x138 [ 22.025732] [<ffffffff8071cd60>] dump_stack+0xf0/0x150 [ 22.030903] [<ffffffff80c73f5c>] check_preemption_disabled+0xf4/0x100 [ 22.037375] [<ffffffff80213b84>] do_ri+0x1d4/0x690 [ 22.042198] [<ffffffff8020b828>] handle_ri_int+0x44/0x5c [ 24.359386] BUG: using smp_processor_id() in preemptible [00000000] code: qemu-system-mip/1072 [ 24.368204] caller is do_ri+0x1a8/0x690 [ 24.372169] CPU: 4 PID: 1072 Comm: qemu-system-mip Not tainted 5.8.0-rc2 #3 [ 24.379170] Stack : 0000000000000001 ffffffff81370000 ffffffff8071cd60 a80f926d5ac95694 [ 24.387246] a80f926d5ac95694 0000000000000000 98001007ef06bc88 ffffffff80f2fe40 [ 24.395318] 0000000000000000 0000000000000000 0000000000000001 0000000000000000 [ 24.403389] ffffffff802d60cc 98001007ef06bdd8 ffffffff81f4b818 ffffffff81f60000 [ 24.411461] ffffffff81f60000 ffffffff80fe0000 ffff000000000000 0000000000000000 [ 24.419533] fffffffff500cce1 0000000000000001 0000000000000002 0000000000000000 [ 24.427603] ffffffff80fe0000 0000000000000006 ffffffff8077f940 0000000000000020 [ 24.435673] ffffffff81460020 98001007ef068000 98001007ef06bc80 000000fffbbbb370 [ 24.443745] ffffffff8071cd60 0000000000000000 0000000000000000 0000000000000000 [ 24.451816] 0000000000000000 0000000000000000 ffffffff80212ab4 a80f926d5ac95694 [ 24.459887] ... [ 24.462367] Call Trace: [ 24.464846] [<ffffffff80212ab4>] show_stack+0xa4/0x138 [ 24.470029] [<ffffffff8071cd60>] dump_stack+0xf0/0x150 [ 24.475208] [<ffffffff80c73f5c>] check_preemption_disabled+0xf4/0x100 [ 24.481682] [<ffffffff80213b58>] do_ri+0x1a8/0x690 [ 24.486509] [<ffffffff8020b828>] handle_ri_int+0x44/0x5c Signed-off-by: Xingxing Su <suxingxing@loongson.cn> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2020-07-03 04:11:58 +00:00
preempt_disable();
if (!loongson3_cpucfg_emulation_enabled(&current_cpu_data)) {
preempt_enable();
return -1;
MIPS: Do not use smp_processor_id() in preemptible code Use preempt_disable() to fix the following bug under CONFIG_DEBUG_PREEMPT. [ 21.915305] BUG: using smp_processor_id() in preemptible [00000000] code: qemu-system-mip/1056 [ 21.923996] caller is do_ri+0x1d4/0x690 [ 21.927921] CPU: 0 PID: 1056 Comm: qemu-system-mip Not tainted 5.8.0-rc2 #3 [ 21.934913] Stack : 0000000000000001 ffffffff81370000 ffffffff8071cd60 a80f926d5ac95694 [ 21.942984] a80f926d5ac95694 0000000000000000 98000007f0043c88 ffffffff80f2fe40 [ 21.951054] 0000000000000000 0000000000000000 0000000000000001 0000000000000000 [ 21.959123] ffffffff802d60cc 98000007f0043dd8 ffffffff81f4b1e8 ffffffff81f60000 [ 21.967192] ffffffff81f60000 ffffffff80fe0000 ffff000000000000 0000000000000000 [ 21.975261] fffffffff500cce1 0000000000000001 0000000000000002 0000000000000000 [ 21.983331] ffffffff80fe1a40 0000000000000006 ffffffff8077f940 0000000000000000 [ 21.991401] ffffffff81460000 98000007f0040000 98000007f0043c80 000000fffba8cf20 [ 21.999471] ffffffff8071cd60 0000000000000000 0000000000000000 0000000000000000 [ 22.007541] 0000000000000000 0000000000000000 ffffffff80212ab4 a80f926d5ac95694 [ 22.015610] ... [ 22.018086] Call Trace: [ 22.020562] [<ffffffff80212ab4>] show_stack+0xa4/0x138 [ 22.025732] [<ffffffff8071cd60>] dump_stack+0xf0/0x150 [ 22.030903] [<ffffffff80c73f5c>] check_preemption_disabled+0xf4/0x100 [ 22.037375] [<ffffffff80213b84>] do_ri+0x1d4/0x690 [ 22.042198] [<ffffffff8020b828>] handle_ri_int+0x44/0x5c [ 24.359386] BUG: using smp_processor_id() in preemptible [00000000] code: qemu-system-mip/1072 [ 24.368204] caller is do_ri+0x1a8/0x690 [ 24.372169] CPU: 4 PID: 1072 Comm: qemu-system-mip Not tainted 5.8.0-rc2 #3 [ 24.379170] Stack : 0000000000000001 ffffffff81370000 ffffffff8071cd60 a80f926d5ac95694 [ 24.387246] a80f926d5ac95694 0000000000000000 98001007ef06bc88 ffffffff80f2fe40 [ 24.395318] 0000000000000000 0000000000000000 0000000000000001 0000000000000000 [ 24.403389] ffffffff802d60cc 98001007ef06bdd8 ffffffff81f4b818 ffffffff81f60000 [ 24.411461] ffffffff81f60000 ffffffff80fe0000 ffff000000000000 0000000000000000 [ 24.419533] fffffffff500cce1 0000000000000001 0000000000000002 0000000000000000 [ 24.427603] ffffffff80fe0000 0000000000000006 ffffffff8077f940 0000000000000020 [ 24.435673] ffffffff81460020 98001007ef068000 98001007ef06bc80 000000fffbbbb370 [ 24.443745] ffffffff8071cd60 0000000000000000 0000000000000000 0000000000000000 [ 24.451816] 0000000000000000 0000000000000000 ffffffff80212ab4 a80f926d5ac95694 [ 24.459887] ... [ 24.462367] Call Trace: [ 24.464846] [<ffffffff80212ab4>] show_stack+0xa4/0x138 [ 24.470029] [<ffffffff8071cd60>] dump_stack+0xf0/0x150 [ 24.475208] [<ffffffff80c73f5c>] check_preemption_disabled+0xf4/0x100 [ 24.481682] [<ffffffff80213b58>] do_ri+0x1a8/0x690 [ 24.486509] [<ffffffff8020b828>] handle_ri_int+0x44/0x5c Signed-off-by: Xingxing Su <suxingxing@loongson.cn> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2020-07-03 04:11:58 +00:00
}
MIPS: emulate CPUCFG instruction on older Loongson64 cores CPUCFG is the instruction for querying processor characteristics on newer Loongson processors, much like CPUID of x86. Since the instruction is supposedly designed to provide a unified way to do feature detection (without having to, for example, parse /proc/cpuinfo which is too heavyweight), it is important to provide compatibility for older cores without native support. Fortunately, most of the fields can be synthesized without changes to semantics. Performance is not really big a concern, because feature detection logic is not expected to be invoked very often in typical userland applications. The instruction can't be emulated on LOONGSON_2EF cores, according to FlyGoat's experiments. Because the LWC2 opcode is assigned to other valid instructions on 2E and 2F, no RI exception is raised for us to intercept. So compatibility is only extended back furthest to Loongson-3A1000. Loongson-2K is covered too, as it is basically a remix of various blocks from the 3A/3B models from a kernel perspective. This is lightly based on Loongson's work on their Linux 3.10 fork, for being the authority on the right feature flags to fill in, where things aren't otherwise discoverable. Signed-off-by: WANG Xuerui <git@xen0n.name> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Huacai Chen <chenhc@lemote.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2020-05-23 13:37:01 +00:00
regs->regs[rd] = loongson3_cpucfg_read_synthesized(
&current_cpu_data, sel);
MIPS: Do not use smp_processor_id() in preemptible code Use preempt_disable() to fix the following bug under CONFIG_DEBUG_PREEMPT. [ 21.915305] BUG: using smp_processor_id() in preemptible [00000000] code: qemu-system-mip/1056 [ 21.923996] caller is do_ri+0x1d4/0x690 [ 21.927921] CPU: 0 PID: 1056 Comm: qemu-system-mip Not tainted 5.8.0-rc2 #3 [ 21.934913] Stack : 0000000000000001 ffffffff81370000 ffffffff8071cd60 a80f926d5ac95694 [ 21.942984] a80f926d5ac95694 0000000000000000 98000007f0043c88 ffffffff80f2fe40 [ 21.951054] 0000000000000000 0000000000000000 0000000000000001 0000000000000000 [ 21.959123] ffffffff802d60cc 98000007f0043dd8 ffffffff81f4b1e8 ffffffff81f60000 [ 21.967192] ffffffff81f60000 ffffffff80fe0000 ffff000000000000 0000000000000000 [ 21.975261] fffffffff500cce1 0000000000000001 0000000000000002 0000000000000000 [ 21.983331] ffffffff80fe1a40 0000000000000006 ffffffff8077f940 0000000000000000 [ 21.991401] ffffffff81460000 98000007f0040000 98000007f0043c80 000000fffba8cf20 [ 21.999471] ffffffff8071cd60 0000000000000000 0000000000000000 0000000000000000 [ 22.007541] 0000000000000000 0000000000000000 ffffffff80212ab4 a80f926d5ac95694 [ 22.015610] ... [ 22.018086] Call Trace: [ 22.020562] [<ffffffff80212ab4>] show_stack+0xa4/0x138 [ 22.025732] [<ffffffff8071cd60>] dump_stack+0xf0/0x150 [ 22.030903] [<ffffffff80c73f5c>] check_preemption_disabled+0xf4/0x100 [ 22.037375] [<ffffffff80213b84>] do_ri+0x1d4/0x690 [ 22.042198] [<ffffffff8020b828>] handle_ri_int+0x44/0x5c [ 24.359386] BUG: using smp_processor_id() in preemptible [00000000] code: qemu-system-mip/1072 [ 24.368204] caller is do_ri+0x1a8/0x690 [ 24.372169] CPU: 4 PID: 1072 Comm: qemu-system-mip Not tainted 5.8.0-rc2 #3 [ 24.379170] Stack : 0000000000000001 ffffffff81370000 ffffffff8071cd60 a80f926d5ac95694 [ 24.387246] a80f926d5ac95694 0000000000000000 98001007ef06bc88 ffffffff80f2fe40 [ 24.395318] 0000000000000000 0000000000000000 0000000000000001 0000000000000000 [ 24.403389] ffffffff802d60cc 98001007ef06bdd8 ffffffff81f4b818 ffffffff81f60000 [ 24.411461] ffffffff81f60000 ffffffff80fe0000 ffff000000000000 0000000000000000 [ 24.419533] fffffffff500cce1 0000000000000001 0000000000000002 0000000000000000 [ 24.427603] ffffffff80fe0000 0000000000000006 ffffffff8077f940 0000000000000020 [ 24.435673] ffffffff81460020 98001007ef068000 98001007ef06bc80 000000fffbbbb370 [ 24.443745] ffffffff8071cd60 0000000000000000 0000000000000000 0000000000000000 [ 24.451816] 0000000000000000 0000000000000000 ffffffff80212ab4 a80f926d5ac95694 [ 24.459887] ... [ 24.462367] Call Trace: [ 24.464846] [<ffffffff80212ab4>] show_stack+0xa4/0x138 [ 24.470029] [<ffffffff8071cd60>] dump_stack+0xf0/0x150 [ 24.475208] [<ffffffff80c73f5c>] check_preemption_disabled+0xf4/0x100 [ 24.481682] [<ffffffff80213b58>] do_ri+0x1a8/0x690 [ 24.486509] [<ffffffff8020b828>] handle_ri_int+0x44/0x5c Signed-off-by: Xingxing Su <suxingxing@loongson.cn> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2020-07-03 04:11:58 +00:00
preempt_enable();
MIPS: emulate CPUCFG instruction on older Loongson64 cores CPUCFG is the instruction for querying processor characteristics on newer Loongson processors, much like CPUID of x86. Since the instruction is supposedly designed to provide a unified way to do feature detection (without having to, for example, parse /proc/cpuinfo which is too heavyweight), it is important to provide compatibility for older cores without native support. Fortunately, most of the fields can be synthesized without changes to semantics. Performance is not really big a concern, because feature detection logic is not expected to be invoked very often in typical userland applications. The instruction can't be emulated on LOONGSON_2EF cores, according to FlyGoat's experiments. Because the LWC2 opcode is assigned to other valid instructions on 2E and 2F, no RI exception is raised for us to intercept. So compatibility is only extended back furthest to Loongson-3A1000. Loongson-2K is covered too, as it is basically a remix of various blocks from the 3A/3B models from a kernel perspective. This is lightly based on Loongson's work on their Linux 3.10 fork, for being the authority on the right feature flags to fill in, where things aren't otherwise discoverable. Signed-off-by: WANG Xuerui <git@xen0n.name> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Huacai Chen <chenhc@lemote.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2020-05-23 13:37:01 +00:00
return 0;
}
/* Not ours. */
return -1;
}
#endif /* CONFIG_CPU_LOONGSON3_CPUCFG_EMULATION */
asmlinkage void do_ov(struct pt_regs *regs)
{
enum ctx_state prev_state;
prev_state = exception_enter();
die_if_kernel("Integer overflow", regs);
force_sig_fault(SIGFPE, FPE_INTOVF, (void __user *)regs->cp0_epc);
exception_exit(prev_state);
}
#ifdef CONFIG_MIPS_FP_SUPPORT
2016-10-28 07:21:03 +00:00
/*
* Send SIGFPE according to FCSR Cause bits, which must have already
* been masked against Enable bits. This is impotant as Inexact can
* happen together with Overflow or Underflow, and `ptrace' can set
* any bits.
*/
void force_fcr31_sig(unsigned long fcr31, void __user *fault_addr,
struct task_struct *tsk)
{
int si_code = FPE_FLTUNK;
2016-10-28 07:21:03 +00:00
if (fcr31 & FPU_CSR_INV_X)
si_code = FPE_FLTINV;
2016-10-28 07:21:03 +00:00
else if (fcr31 & FPU_CSR_DIV_X)
si_code = FPE_FLTDIV;
2016-10-28 07:21:03 +00:00
else if (fcr31 & FPU_CSR_OVF_X)
si_code = FPE_FLTOVF;
2016-10-28 07:21:03 +00:00
else if (fcr31 & FPU_CSR_UDF_X)
si_code = FPE_FLTUND;
2016-10-28 07:21:03 +00:00
else if (fcr31 & FPU_CSR_INE_X)
si_code = FPE_FLTRES;
force_sig_fault_to_task(SIGFPE, si_code, fault_addr, tsk);
2016-10-28 07:21:03 +00:00
}
int process_fpemu_return(int sig, void __user *fault_addr, unsigned long fcr31)
{
int si_code;
switch (sig) {
case 0:
return 0;
case SIGFPE:
2016-10-28 07:21:03 +00:00
force_fcr31_sig(fcr31, fault_addr, current);
return 1;
case SIGBUS:
force_sig_fault(SIGBUS, BUS_ADRERR, fault_addr);
return 1;
case SIGSEGV:
mmap locking API: use coccinelle to convert mmap_sem rwsem call sites This change converts the existing mmap_sem rwsem calls to use the new mmap locking API instead. The change is generated using coccinelle with the following rule: // spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir . @@ expression mm; @@ ( -init_rwsem +mmap_init_lock | -down_write +mmap_write_lock | -down_write_killable +mmap_write_lock_killable | -down_write_trylock +mmap_write_trylock | -up_write +mmap_write_unlock | -downgrade_write +mmap_write_downgrade | -down_read +mmap_read_lock | -down_read_killable +mmap_read_lock_killable | -down_read_trylock +mmap_read_trylock | -up_read +mmap_read_unlock ) -(&mm->mmap_sem) +(mm) Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 04:33:25 +00:00
mmap_read_lock(current->mm);
if (vma_lookup(current->mm, (unsigned long)fault_addr))
si_code = SEGV_ACCERR;
else
si_code = SEGV_MAPERR;
mmap locking API: use coccinelle to convert mmap_sem rwsem call sites This change converts the existing mmap_sem rwsem calls to use the new mmap locking API instead. The change is generated using coccinelle with the following rule: // spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir . @@ expression mm; @@ ( -init_rwsem +mmap_init_lock | -down_write +mmap_write_lock | -down_write_killable +mmap_write_lock_killable | -down_write_trylock +mmap_write_trylock | -up_write +mmap_write_unlock | -downgrade_write +mmap_write_downgrade | -down_read +mmap_read_lock | -down_read_killable +mmap_read_lock_killable | -down_read_trylock +mmap_read_trylock | -up_read +mmap_read_unlock ) -(&mm->mmap_sem) +(mm) Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 04:33:25 +00:00
mmap_read_unlock(current->mm);
force_sig_fault(SIGSEGV, si_code, fault_addr);
return 1;
default:
force_sig(sig);
return 1;
}
}
MIPS: Support for hybrid FPRs Hybrid FPRs is a scheme where scalar FP registers are 64b wide, but accesses to odd indexed single registers use bits 63:32 of the preceeding even indexed 64b register. In this mode all FP code except that built for the plain FP64 ABI can execute correctly. Most notably a combination of FP64A & FP32 code can execute correctly, allowing for existing FP32 binaries to be linked with new FP64A binaries that can make use of 64 bit FP & MSA. Hybrid FPRs are implemented by setting both the FR & FRE bits, trapping & emulating single precision FP instructions (via Reserved Instruction exceptions) whilst allowing others to execute natively. It therefore has a penalty in terms of execution speed, and should only be used when no fully native mode can be. As more binaries are recompiled to use either the FPXX or FP64(A) ABIs, the need for hybrid FPRs should diminish. However in the short to mid term it allows for a gradual transition towards that world, rather than a complete ABI break which is not feasible for some users & not desirable for many. A task will be executed using the hybrid FPR scheme when its TIF_HYBRID_FPREGS flag is set & TIF_32BIT_FPREGS is clear. A further patch will set the flags as necessary, this patch simply adds the infrastructure necessary for the hybrid FPR mode to work. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/7683/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-09-11 07:30:20 +00:00
static int simulate_fp(struct pt_regs *regs, unsigned int opcode,
unsigned long old_epc, unsigned long old_ra)
{
union mips_instruction inst = { .word = opcode };
void __user *fault_addr;
unsigned long fcr31;
MIPS: Support for hybrid FPRs Hybrid FPRs is a scheme where scalar FP registers are 64b wide, but accesses to odd indexed single registers use bits 63:32 of the preceeding even indexed 64b register. In this mode all FP code except that built for the plain FP64 ABI can execute correctly. Most notably a combination of FP64A & FP32 code can execute correctly, allowing for existing FP32 binaries to be linked with new FP64A binaries that can make use of 64 bit FP & MSA. Hybrid FPRs are implemented by setting both the FR & FRE bits, trapping & emulating single precision FP instructions (via Reserved Instruction exceptions) whilst allowing others to execute natively. It therefore has a penalty in terms of execution speed, and should only be used when no fully native mode can be. As more binaries are recompiled to use either the FPXX or FP64(A) ABIs, the need for hybrid FPRs should diminish. However in the short to mid term it allows for a gradual transition towards that world, rather than a complete ABI break which is not feasible for some users & not desirable for many. A task will be executed using the hybrid FPR scheme when its TIF_HYBRID_FPREGS flag is set & TIF_32BIT_FPREGS is clear. A further patch will set the flags as necessary, this patch simply adds the infrastructure necessary for the hybrid FPR mode to work. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/7683/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-09-11 07:30:20 +00:00
int sig;
/* If it's obviously not an FP instruction, skip it */
switch (inst.i_format.opcode) {
case cop1_op:
case cop1x_op:
case lwc1_op:
case ldc1_op:
case swc1_op:
case sdc1_op:
break;
default:
return -1;
}
/*
* do_ri skipped over the instruction via compute_return_epc, undo
* that for the FPU emulator.
*/
regs->cp0_epc = old_epc;
regs->regs[31] = old_ra;
/* Run the emulator */
sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
&fault_addr);
/*
2016-10-28 07:21:03 +00:00
* We can't allow the emulated instruction to leave any
* enabled Cause bits set in $fcr31.
*/
2016-10-28 07:21:03 +00:00
fcr31 = mask_fcr31_x(current->thread.fpu.fcr31);
current->thread.fpu.fcr31 &= ~fcr31;
MIPS: Support for hybrid FPRs Hybrid FPRs is a scheme where scalar FP registers are 64b wide, but accesses to odd indexed single registers use bits 63:32 of the preceeding even indexed 64b register. In this mode all FP code except that built for the plain FP64 ABI can execute correctly. Most notably a combination of FP64A & FP32 code can execute correctly, allowing for existing FP32 binaries to be linked with new FP64A binaries that can make use of 64 bit FP & MSA. Hybrid FPRs are implemented by setting both the FR & FRE bits, trapping & emulating single precision FP instructions (via Reserved Instruction exceptions) whilst allowing others to execute natively. It therefore has a penalty in terms of execution speed, and should only be used when no fully native mode can be. As more binaries are recompiled to use either the FPXX or FP64(A) ABIs, the need for hybrid FPRs should diminish. However in the short to mid term it allows for a gradual transition towards that world, rather than a complete ABI break which is not feasible for some users & not desirable for many. A task will be executed using the hybrid FPR scheme when its TIF_HYBRID_FPREGS flag is set & TIF_32BIT_FPREGS is clear. A further patch will set the flags as necessary, this patch simply adds the infrastructure necessary for the hybrid FPR mode to work. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/7683/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-09-11 07:30:20 +00:00
/* Restore the hardware register state */
own_fpu(1);
/* Send a signal if required. */
process_fpemu_return(sig, fault_addr, fcr31);
MIPS: Support for hybrid FPRs Hybrid FPRs is a scheme where scalar FP registers are 64b wide, but accesses to odd indexed single registers use bits 63:32 of the preceeding even indexed 64b register. In this mode all FP code except that built for the plain FP64 ABI can execute correctly. Most notably a combination of FP64A & FP32 code can execute correctly, allowing for existing FP32 binaries to be linked with new FP64A binaries that can make use of 64 bit FP & MSA. Hybrid FPRs are implemented by setting both the FR & FRE bits, trapping & emulating single precision FP instructions (via Reserved Instruction exceptions) whilst allowing others to execute natively. It therefore has a penalty in terms of execution speed, and should only be used when no fully native mode can be. As more binaries are recompiled to use either the FPXX or FP64(A) ABIs, the need for hybrid FPRs should diminish. However in the short to mid term it allows for a gradual transition towards that world, rather than a complete ABI break which is not feasible for some users & not desirable for many. A task will be executed using the hybrid FPR scheme when its TIF_HYBRID_FPREGS flag is set & TIF_32BIT_FPREGS is clear. A further patch will set the flags as necessary, this patch simply adds the infrastructure necessary for the hybrid FPR mode to work. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/7683/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-09-11 07:30:20 +00:00
return 0;
}
/*
* XXX Delayed fp exceptions when doing a lazy ctx switch XXX
*/
asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
{
enum ctx_state prev_state;
void __user *fault_addr;
int sig;
prev_state = exception_enter();
if (notify_die(DIE_FP, "FP exception", regs, 0, current->thread.trap_nr,
SIGFPE) == NOTIFY_STOP)
goto out;
MIPS: Clear [MSA]FPE CSR.Cause after notify_die() When handling floating point exceptions (FPEs) and MSA FPEs the Cause bits of the appropriate control and status register (FCSR for FPEs and MSACSR for MSA FPEs) are read and cleared before enabling interrupts, presumably so that it doesn't have to go through the pain of restoring those bits if the process is pre-empted, since writing those bits would cause another immediate exception while still in the kernel. The bits aren't normally ever restored again, since userland never expects to see them set. However for virtualisation it is necessary for the kernel to be able to restore these Cause bits, as the guest may have been interrupted in an FP exception handler but before it could read the Cause bits. This can be done by registering a die notifier, to get notified of the exception when such a value is restored, and if the PC was at the instruction which is used to restore the guest state, the handler can step over it and continue execution. The Cause bits can then remain set without causing further exceptions. For this to work safely a few changes are made: - __build_clear_fpe and __build_clear_msa_fpe no longer clear the Cause bits, and now return from exception level with interrupts disabled instead of enabled. - do_fpe() now clears the Cause bits and enables interrupts after notify_die() is called, so that the notifier can chose to return from exception without this happening. - do_msa_fpe() acts similarly, but now actually makes use of the second argument (msacsr) and calls notify_die() with the new DIE_MSAFP, allowing die notifiers to be informed of MSA FPEs too. Signed-off-by: James Hogan <james.hogan@imgtec.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
2014-12-02 13:44:13 +00:00
/* Clear FCSR.Cause before enabling interrupts */
2016-10-28 07:21:03 +00:00
write_32bit_cp1_register(CP1_STATUS, fcr31 & ~mask_fcr31_x(fcr31));
MIPS: Clear [MSA]FPE CSR.Cause after notify_die() When handling floating point exceptions (FPEs) and MSA FPEs the Cause bits of the appropriate control and status register (FCSR for FPEs and MSACSR for MSA FPEs) are read and cleared before enabling interrupts, presumably so that it doesn't have to go through the pain of restoring those bits if the process is pre-empted, since writing those bits would cause another immediate exception while still in the kernel. The bits aren't normally ever restored again, since userland never expects to see them set. However for virtualisation it is necessary for the kernel to be able to restore these Cause bits, as the guest may have been interrupted in an FP exception handler but before it could read the Cause bits. This can be done by registering a die notifier, to get notified of the exception when such a value is restored, and if the PC was at the instruction which is used to restore the guest state, the handler can step over it and continue execution. The Cause bits can then remain set without causing further exceptions. For this to work safely a few changes are made: - __build_clear_fpe and __build_clear_msa_fpe no longer clear the Cause bits, and now return from exception level with interrupts disabled instead of enabled. - do_fpe() now clears the Cause bits and enables interrupts after notify_die() is called, so that the notifier can chose to return from exception without this happening. - do_msa_fpe() acts similarly, but now actually makes use of the second argument (msacsr) and calls notify_die() with the new DIE_MSAFP, allowing die notifiers to be informed of MSA FPEs too. Signed-off-by: James Hogan <james.hogan@imgtec.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
2014-12-02 13:44:13 +00:00
local_irq_enable();
die_if_kernel("FP exception in kernel code", regs);
if (fcr31 & FPU_CSR_UNI_X) {
/*
* Unimplemented operation exception. If we've got the full
* software emulator on-board, let's use it...
*
* Force FPU to dump state into task/thread context. We're
* moving a lot of data here for what is probably a single
* instruction, but the alternative is to pre-decode the FP
* register operands before invoking the emulator, which seems
* a bit extreme for what should be an infrequent event.
*/
/* Run the emulator */
sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
&fault_addr);
/*
2016-10-28 07:21:03 +00:00
* We can't allow the emulated instruction to leave any
* enabled Cause bits set in $fcr31.
*/
2016-10-28 07:21:03 +00:00
fcr31 = mask_fcr31_x(current->thread.fpu.fcr31);
current->thread.fpu.fcr31 &= ~fcr31;
/* Restore the hardware register state */
own_fpu(1); /* Using the FPU again. */
} else {
sig = SIGFPE;
fault_addr = (void __user *) regs->cp0_epc;
}
/* Send a signal if required. */
process_fpemu_return(sig, fault_addr, fcr31);
out:
exception_exit(prev_state);
}
/*
* MIPS MT processors may have fewer FPU contexts than CPU threads. If we've
* emulated more than some threshold number of instructions, force migration to
* a "CPU" that has FP support.
*/
static void mt_ase_fp_affinity(void)
{
#ifdef CONFIG_MIPS_MT_FPAFF
if (mt_fpemul_threshold > 0 &&
((current->thread.emulated_fp++ > mt_fpemul_threshold))) {
/*
* If there's no FPU present, or if the application has already
* restricted the allowed set to exclude any CPUs with FPUs,
* we'll skip the procedure.
*/
if (cpumask_intersects(&current->cpus_mask, &mt_fpu_cpumask)) {
cpumask_t tmask;
current->thread.user_cpus_allowed
= current->cpus_mask;
cpumask_and(&tmask, &current->cpus_mask,
&mt_fpu_cpumask);
set_cpus_allowed_ptr(current, &tmask);
set_thread_flag(TIF_FPUBOUND);
}
}
#endif /* CONFIG_MIPS_MT_FPAFF */
}
#else /* !CONFIG_MIPS_FP_SUPPORT */
static int simulate_fp(struct pt_regs *regs, unsigned int opcode,
unsigned long old_epc, unsigned long old_ra)
{
return -1;
}
#endif /* !CONFIG_MIPS_FP_SUPPORT */
void do_trap_or_bp(struct pt_regs *regs, unsigned int code, int si_code,
const char *str)
{
char b[40];
#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
if (kgdb_ll_trap(DIE_TRAP, str, regs, code, current->thread.trap_nr,
SIGTRAP) == NOTIFY_STOP)
return;
#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
if (notify_die(DIE_TRAP, str, regs, code, current->thread.trap_nr,
SIGTRAP) == NOTIFY_STOP)
return;
/*
* A short test says that IRIX 5.3 sends SIGTRAP for all trap
* insns, even for trap and break codes that indicate arithmetic
* failures. Weird ...
* But should we continue the brokenness??? --macro
*/
switch (code) {
case BRK_OVERFLOW:
case BRK_DIVZERO:
scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
die_if_kernel(b, regs);
force_sig_fault(SIGFPE,
code == BRK_DIVZERO ? FPE_INTDIV : FPE_INTOVF,
(void __user *) regs->cp0_epc);
break;
case BRK_BUG:
die_if_kernel("Kernel bug detected", regs);
force_sig(SIGTRAP);
break;
case BRK_MEMU:
/*
* This breakpoint code is used by the FPU emulator to retake
* control of the CPU after executing the instruction from the
* delay slot of an emulated branch.
*
* Terminate if exception was recognized as a delay slot return
* otherwise handle as normal.
*/
if (do_dsemulret(regs))
return;
die_if_kernel("Math emu break/trap", regs);
force_sig(SIGTRAP);
break;
default:
scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
die_if_kernel(b, regs);
if (si_code) {
force_sig_fault(SIGTRAP, si_code, NULL);
} else {
force_sig(SIGTRAP);
}
}
}
asmlinkage void do_bp(struct pt_regs *regs)
{
unsigned long epc = msk_isa16_mode(exception_epc(regs));
unsigned int opcode, bcode;
enum ctx_state prev_state;
bool user = user_mode(regs);
prev_state = exception_enter();
current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
if (get_isa16_mode(regs->cp0_epc)) {
u16 instr[2];
if (__get_inst16(&instr[0], (u16 *)epc, user))
goto out_sigsegv;
if (!cpu_has_mmips) {
/* MIPS16e mode */
bcode = (instr[0] >> 5) & 0x3f;
} else if (mm_insn_16bit(instr[0])) {
/* 16-bit microMIPS BREAK */
bcode = instr[0] & 0xf;
} else {
/* 32-bit microMIPS BREAK */
if (__get_inst16(&instr[1], (u16 *)(epc + 2), user))
goto out_sigsegv;
opcode = (instr[0] << 16) | instr[1];
bcode = (opcode >> 6) & ((1 << 20) - 1);
}
} else {
if (__get_inst32(&opcode, (u32 *)epc, user))
goto out_sigsegv;
bcode = (opcode >> 6) & ((1 << 20) - 1);
}
/*
* There is the ancient bug in the MIPS assemblers that the break
* code starts left to bit 16 instead to bit 6 in the opcode.
* Gas is bug-compatible, but not always, grrr...
* We handle both cases with a simple heuristics. --macro
*/
if (bcode >= (1 << 10))
bcode = ((bcode & ((1 << 10) - 1)) << 10) | (bcode >> 10);
/*
* notify the kprobe handlers, if instruction is likely to
* pertain to them.
*/
switch (bcode) {
case BRK_UPROBE:
if (notify_die(DIE_UPROBE, "uprobe", regs, bcode,
current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
goto out;
else
break;
case BRK_UPROBE_XOL:
if (notify_die(DIE_UPROBE_XOL, "uprobe_xol", regs, bcode,
current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
goto out;
else
break;
case BRK_KPROBE_BP:
if (notify_die(DIE_BREAK, "debug", regs, bcode,
current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
goto out;
else
break;
case BRK_KPROBE_SSTEPBP:
if (notify_die(DIE_SSTEPBP, "single_step", regs, bcode,
current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
goto out;
else
break;
default:
break;
}
do_trap_or_bp(regs, bcode, TRAP_BRKPT, "Break");
out:
exception_exit(prev_state);
return;
out_sigsegv:
force_sig(SIGSEGV);
goto out;
}
asmlinkage void do_tr(struct pt_regs *regs)
{
u32 opcode, tcode = 0;
enum ctx_state prev_state;
u16 instr[2];
bool user = user_mode(regs);
unsigned long epc = msk_isa16_mode(exception_epc(regs));
prev_state = exception_enter();
current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
if (get_isa16_mode(regs->cp0_epc)) {
if (__get_inst16(&instr[0], (u16 *)(epc + 0), user) ||
__get_inst16(&instr[1], (u16 *)(epc + 2), user))
goto out_sigsegv;
opcode = (instr[0] << 16) | instr[1];
/* Immediate versions don't provide a code. */
if (!(opcode & OPCODE))
tcode = (opcode >> 12) & ((1 << 4) - 1);
} else {
if (__get_inst32(&opcode, (u32 *)epc, user))
goto out_sigsegv;
/* Immediate versions don't provide a code. */
if (!(opcode & OPCODE))
tcode = (opcode >> 6) & ((1 << 10) - 1);
}
do_trap_or_bp(regs, tcode, 0, "Trap");
out:
exception_exit(prev_state);
return;
out_sigsegv:
force_sig(SIGSEGV);
goto out;
}
asmlinkage void do_ri(struct pt_regs *regs)
{
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
unsigned int __user *epc = (unsigned int __user *)exception_epc(regs);
unsigned long old_epc = regs->cp0_epc;
unsigned long old31 = regs->regs[31];
enum ctx_state prev_state;
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
unsigned int opcode = 0;
int status = -1;
/*
* Avoid any kernel code. Just emulate the R2 instruction
* as quickly as possible.
*/
if (mipsr2_emulation && cpu_has_mips_r6 &&
likely(user_mode(regs)) &&
likely(get_user(opcode, epc) >= 0)) {
unsigned long fcr31 = 0;
status = mipsr2_decoder(regs, opcode, &fcr31);
switch (status) {
case 0:
case SIGEMT:
return;
case SIGILL:
goto no_r2_instr;
default:
process_fpemu_return(status,
&current->thread.cp0_baduaddr,
fcr31);
return;
}
}
no_r2_instr:
prev_state = exception_enter();
current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
if (notify_die(DIE_RI, "RI Fault", regs, 0, current->thread.trap_nr,
SIGILL) == NOTIFY_STOP)
goto out;
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
die_if_kernel("Reserved instruction in kernel code", regs);
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
if (unlikely(compute_return_epc(regs) < 0))
goto out;
if (!get_isa16_mode(regs->cp0_epc)) {
if (unlikely(get_user(opcode, epc) < 0))
status = SIGSEGV;
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
if (!cpu_has_llsc && status < 0)
status = simulate_llsc(regs, opcode);
if (status < 0)
status = simulate_rdhwr_normal(regs, opcode);
if (status < 0)
status = simulate_sync(regs, opcode);
MIPS: Support for hybrid FPRs Hybrid FPRs is a scheme where scalar FP registers are 64b wide, but accesses to odd indexed single registers use bits 63:32 of the preceeding even indexed 64b register. In this mode all FP code except that built for the plain FP64 ABI can execute correctly. Most notably a combination of FP64A & FP32 code can execute correctly, allowing for existing FP32 binaries to be linked with new FP64A binaries that can make use of 64 bit FP & MSA. Hybrid FPRs are implemented by setting both the FR & FRE bits, trapping & emulating single precision FP instructions (via Reserved Instruction exceptions) whilst allowing others to execute natively. It therefore has a penalty in terms of execution speed, and should only be used when no fully native mode can be. As more binaries are recompiled to use either the FPXX or FP64(A) ABIs, the need for hybrid FPRs should diminish. However in the short to mid term it allows for a gradual transition towards that world, rather than a complete ABI break which is not feasible for some users & not desirable for many. A task will be executed using the hybrid FPR scheme when its TIF_HYBRID_FPREGS flag is set & TIF_32BIT_FPREGS is clear. A further patch will set the flags as necessary, this patch simply adds the infrastructure necessary for the hybrid FPR mode to work. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/7683/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-09-11 07:30:20 +00:00
if (status < 0)
status = simulate_fp(regs, opcode, old_epc, old31);
MIPS: emulate CPUCFG instruction on older Loongson64 cores CPUCFG is the instruction for querying processor characteristics on newer Loongson processors, much like CPUID of x86. Since the instruction is supposedly designed to provide a unified way to do feature detection (without having to, for example, parse /proc/cpuinfo which is too heavyweight), it is important to provide compatibility for older cores without native support. Fortunately, most of the fields can be synthesized without changes to semantics. Performance is not really big a concern, because feature detection logic is not expected to be invoked very often in typical userland applications. The instruction can't be emulated on LOONGSON_2EF cores, according to FlyGoat's experiments. Because the LWC2 opcode is assigned to other valid instructions on 2E and 2F, no RI exception is raised for us to intercept. So compatibility is only extended back furthest to Loongson-3A1000. Loongson-2K is covered too, as it is basically a remix of various blocks from the 3A/3B models from a kernel perspective. This is lightly based on Loongson's work on their Linux 3.10 fork, for being the authority on the right feature flags to fill in, where things aren't otherwise discoverable. Signed-off-by: WANG Xuerui <git@xen0n.name> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Huacai Chen <chenhc@lemote.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2020-05-23 13:37:01 +00:00
#ifdef CONFIG_CPU_LOONGSON3_CPUCFG_EMULATION
if (status < 0)
status = simulate_loongson3_cpucfg(regs, opcode);
#endif
} else if (cpu_has_mmips) {
unsigned short mmop[2] = { 0 };
if (unlikely(get_user(mmop[0], (u16 __user *)epc + 0) < 0))
status = SIGSEGV;
if (unlikely(get_user(mmop[1], (u16 __user *)epc + 1) < 0))
status = SIGSEGV;
opcode = mmop[0];
opcode = (opcode << 16) | mmop[1];
if (status < 0)
status = simulate_rdhwr_mm(regs, opcode);
}
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
if (status < 0)
status = SIGILL;
if (unlikely(status > 0)) {
regs->cp0_epc = old_epc; /* Undo skip-over. */
regs->regs[31] = old31;
force_sig(status);
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
}
out:
exception_exit(prev_state);
}
/*
* No lock; only written during early bootup by CPU 0.
*/
static RAW_NOTIFIER_HEAD(cu2_chain);
int __ref register_cu2_notifier(struct notifier_block *nb)
{
return raw_notifier_chain_register(&cu2_chain, nb);
}
int cu2_notifier_call_chain(unsigned long val, void *v)
{
return raw_notifier_call_chain(&cu2_chain, val, v);
}
static int default_cu2_call(struct notifier_block *nfb, unsigned long action,
void *data)
{
struct pt_regs *regs = data;
die_if_kernel("COP2: Unhandled kernel unaligned access or invalid "
"instruction", regs);
force_sig(SIGILL);
return NOTIFY_OK;
}
#ifdef CONFIG_MIPS_FP_SUPPORT
static int enable_restore_fp_context(int msa)
{
int err, was_fpu_owner, prior_msa;
MIPS: Simplify FP context initialization MIPS has up until now had 3 different ways for a task's floating point context to be initialized: - If the task's first use of FP involves it gaining ownership of an FPU then _init_fpu() is used to initialize the FPU's registers such that they all contain ~0, and the FPU registers will be stored to struct thread_info later (eg. when context switching). - If the task first uses FP on a CPU without an associated FPU then fpu_emulator_init_fpu() initializes the task's floating point register state in struct thread_info such that all floating point register contain the bit pattern 0x7ff800007ff80000, different to the _init_fpu() behaviour. - If a task's floating point context is first accessed via ptrace then init_fp_ctx() initializes the floating point register state in struct thread_info to ~0, giving equivalent state to _init_fpu(). The _init_fpu() path has 2 separate implementations - one for r2k/r3k style systems & one for r4k style systems. The _init_fpu() path also requires that we be careful to clear & restore the value of the Config5.FRE bit on modern systems in order to avoid inadvertently triggering floating point exceptions. None of this code is in a performance critical hot path - it runs only the first time a task uses floating point. As such it doesn't seem to warrant the complications of maintaining the _init_fpu() path. Remove _init_fpu() & fpu_emulator_init_fpu(), instead using init_fp_ctx() consistently to initialize floating point register state in struct thread_info. Upon a task's first use of floating point this will typically mean that we initialize state in memory & then load it into FPU registers using _restore_fp() just as we would on a context switch. For other paths such as __compute_return_epc_for_insn() or mipsr2_decoder() this results in a significant simplification of the work to be done. Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/21002/ Cc: linux-mips@linux-mips.org
2018-11-07 23:13:59 +00:00
bool first_fp;
MIPS: Simplify FP context initialization MIPS has up until now had 3 different ways for a task's floating point context to be initialized: - If the task's first use of FP involves it gaining ownership of an FPU then _init_fpu() is used to initialize the FPU's registers such that they all contain ~0, and the FPU registers will be stored to struct thread_info later (eg. when context switching). - If the task first uses FP on a CPU without an associated FPU then fpu_emulator_init_fpu() initializes the task's floating point register state in struct thread_info such that all floating point register contain the bit pattern 0x7ff800007ff80000, different to the _init_fpu() behaviour. - If a task's floating point context is first accessed via ptrace then init_fp_ctx() initializes the floating point register state in struct thread_info to ~0, giving equivalent state to _init_fpu(). The _init_fpu() path has 2 separate implementations - one for r2k/r3k style systems & one for r4k style systems. The _init_fpu() path also requires that we be careful to clear & restore the value of the Config5.FRE bit on modern systems in order to avoid inadvertently triggering floating point exceptions. None of this code is in a performance critical hot path - it runs only the first time a task uses floating point. As such it doesn't seem to warrant the complications of maintaining the _init_fpu() path. Remove _init_fpu() & fpu_emulator_init_fpu(), instead using init_fp_ctx() consistently to initialize floating point register state in struct thread_info. Upon a task's first use of floating point this will typically mean that we initialize state in memory & then load it into FPU registers using _restore_fp() just as we would on a context switch. For other paths such as __compute_return_epc_for_insn() or mipsr2_decoder() this results in a significant simplification of the work to be done. Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/21002/ Cc: linux-mips@linux-mips.org
2018-11-07 23:13:59 +00:00
/* Initialize context if it hasn't been used already */
first_fp = init_fp_ctx(current);
MIPS: Simplify FP context initialization MIPS has up until now had 3 different ways for a task's floating point context to be initialized: - If the task's first use of FP involves it gaining ownership of an FPU then _init_fpu() is used to initialize the FPU's registers such that they all contain ~0, and the FPU registers will be stored to struct thread_info later (eg. when context switching). - If the task first uses FP on a CPU without an associated FPU then fpu_emulator_init_fpu() initializes the task's floating point register state in struct thread_info such that all floating point register contain the bit pattern 0x7ff800007ff80000, different to the _init_fpu() behaviour. - If a task's floating point context is first accessed via ptrace then init_fp_ctx() initializes the floating point register state in struct thread_info to ~0, giving equivalent state to _init_fpu(). The _init_fpu() path has 2 separate implementations - one for r2k/r3k style systems & one for r4k style systems. The _init_fpu() path also requires that we be careful to clear & restore the value of the Config5.FRE bit on modern systems in order to avoid inadvertently triggering floating point exceptions. None of this code is in a performance critical hot path - it runs only the first time a task uses floating point. As such it doesn't seem to warrant the complications of maintaining the _init_fpu() path. Remove _init_fpu() & fpu_emulator_init_fpu(), instead using init_fp_ctx() consistently to initialize floating point register state in struct thread_info. Upon a task's first use of floating point this will typically mean that we initialize state in memory & then load it into FPU registers using _restore_fp() just as we would on a context switch. For other paths such as __compute_return_epc_for_insn() or mipsr2_decoder() this results in a significant simplification of the work to be done. Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/21002/ Cc: linux-mips@linux-mips.org
2018-11-07 23:13:59 +00:00
if (first_fp) {
preempt_disable();
MIPS: Simplify FP context initialization MIPS has up until now had 3 different ways for a task's floating point context to be initialized: - If the task's first use of FP involves it gaining ownership of an FPU then _init_fpu() is used to initialize the FPU's registers such that they all contain ~0, and the FPU registers will be stored to struct thread_info later (eg. when context switching). - If the task first uses FP on a CPU without an associated FPU then fpu_emulator_init_fpu() initializes the task's floating point register state in struct thread_info such that all floating point register contain the bit pattern 0x7ff800007ff80000, different to the _init_fpu() behaviour. - If a task's floating point context is first accessed via ptrace then init_fp_ctx() initializes the floating point register state in struct thread_info to ~0, giving equivalent state to _init_fpu(). The _init_fpu() path has 2 separate implementations - one for r2k/r3k style systems & one for r4k style systems. The _init_fpu() path also requires that we be careful to clear & restore the value of the Config5.FRE bit on modern systems in order to avoid inadvertently triggering floating point exceptions. None of this code is in a performance critical hot path - it runs only the first time a task uses floating point. As such it doesn't seem to warrant the complications of maintaining the _init_fpu() path. Remove _init_fpu() & fpu_emulator_init_fpu(), instead using init_fp_ctx() consistently to initialize floating point register state in struct thread_info. Upon a task's first use of floating point this will typically mean that we initialize state in memory & then load it into FPU registers using _restore_fp() just as we would on a context switch. For other paths such as __compute_return_epc_for_insn() or mipsr2_decoder() this results in a significant simplification of the work to be done. Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/21002/ Cc: linux-mips@linux-mips.org
2018-11-07 23:13:59 +00:00
err = own_fpu_inatomic(1);
if (msa && !err) {
enable_msa();
/*
* with MSA enabled, userspace can see MSACSR
* and MSA regs, but the values in them are from
* other task before current task, restore them
* from saved fp/msa context
*/
write_msa_csr(current->thread.fpu.msacsr);
/*
* own_fpu_inatomic(1) just restore low 64bit,
* fix the high 64bit
*/
init_msa_upper();
set_thread_flag(TIF_USEDMSA);
set_thread_flag(TIF_MSA_CTX_LIVE);
}
preempt_enable();
return err;
}
/*
* This task has formerly used the FP context.
*
* If this thread has no live MSA vector context then we can simply
* restore the scalar FP context. If it has live MSA vector context
* (that is, it has or may have used MSA since last performing a
* function call) then we'll need to restore the vector context. This
* applies even if we're currently only executing a scalar FP
* instruction. This is because if we were to later execute an MSA
* instruction then we'd either have to:
*
* - Restore the vector context & clobber any registers modified by
* scalar FP instructions between now & then.
*
* or
*
* - Not restore the vector context & lose the most significant bits
* of all vector registers.
*
* Neither of those options is acceptable. We cannot restore the least
* significant bits of the registers now & only restore the most
* significant bits later because the most significant bits of any
* vector registers whose aliased FP register is modified now will have
* been zeroed. We'd have no way to know that when restoring the vector
* context & thus may load an outdated value for the most significant
* bits of a vector register.
*/
if (!msa && !thread_msa_context_live())
return own_fpu(1);
/*
* This task is using or has previously used MSA. Thus we require
* that Status.FR == 1.
*/
preempt_disable();
was_fpu_owner = is_fpu_owner();
err = own_fpu_inatomic(0);
if (err)
goto out;
enable_msa();
write_msa_csr(current->thread.fpu.msacsr);
set_thread_flag(TIF_USEDMSA);
/*
* If this is the first time that the task is using MSA and it has
* previously used scalar FP in this time slice then we already nave
* FP context which we shouldn't clobber. We do however need to clear
* the upper 64b of each vector register so that this task has no
* opportunity to see data left behind by another.
*/
prior_msa = test_and_set_thread_flag(TIF_MSA_CTX_LIVE);
if (!prior_msa && was_fpu_owner) {
init_msa_upper();
goto out;
}
if (!prior_msa) {
/*
* Restore the least significant 64b of each vector register
* from the existing scalar FP context.
*/
_restore_fp(current);
/*
* The task has not formerly used MSA, so clear the upper 64b
* of each vector register such that it cannot see data left
* behind by another task.
*/
init_msa_upper();
} else {
/* We need to restore the vector context. */
restore_msa(current);
/* Restore the scalar FP control & status register */
if (!was_fpu_owner)
write_32bit_cp1_register(CP1_STATUS,
current->thread.fpu.fcr31);
}
out:
preempt_enable();
return 0;
}
#else /* !CONFIG_MIPS_FP_SUPPORT */
static int enable_restore_fp_context(int msa)
{
return SIGILL;
}
#endif /* CONFIG_MIPS_FP_SUPPORT */
asmlinkage void do_cpu(struct pt_regs *regs)
{
enum ctx_state prev_state;
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
unsigned int __user *epc;
unsigned long old_epc, old31;
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
unsigned int opcode;
unsigned int cpid;
int status;
prev_state = exception_enter();
cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
if (cpid != 2)
die_if_kernel("do_cpu invoked from kernel context!", regs);
switch (cpid) {
case 0:
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
epc = (unsigned int __user *)exception_epc(regs);
old_epc = regs->cp0_epc;
old31 = regs->regs[31];
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
opcode = 0;
status = -1;
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
if (unlikely(compute_return_epc(regs) < 0))
break;
if (!get_isa16_mode(regs->cp0_epc)) {
if (unlikely(get_user(opcode, epc) < 0))
status = SIGSEGV;
if (!cpu_has_llsc && status < 0)
status = simulate_llsc(regs, opcode);
}
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
if (status < 0)
status = SIGILL;
if (unlikely(status > 0)) {
regs->cp0_epc = old_epc; /* Undo skip-over. */
regs->regs[31] = old31;
force_sig(status);
[MIPS] SYNC emulation for MIPS I processors Userland, including the C library and the dynamic linker, is keen to use the SYNC instruction, even for "generic" MIPS I binaries these days. Which makes it less than useful on MIPS I processors. This change adds the emulation, but as our do_ri() infrastructure was not really prepared to take yet another instruction, I have rewritten it and its callees slightly as follows. Now there is only a single place a possible signal is thrown from. The place is at the end of do_ri(). The instruction word is fetched in do_ri() and passed down to handlers. The handlers are called in sequence and return a result that lets the caller decide upon further processing. If the result is positive, then the handler has picked the instruction, but a signal should be thrown and the result is the signal number. If the result is zero, then the handler has successfully simulated the instruction. If the result is negative, then the handler did not handle the instruction; to make it more obvious the calls do not follow the usual 0/-Exxx result convention they now return -1 instead of -EFAULT. The calculation of the return EPC is now at the beginning. The reason is it is easier to handle it there as emulation callees may modify a register and an instruction may be located in delay slot of a branch whose result depends on the register. It has to be undone if a signal is to be raised, but it is not a problem as this is the slow-path case, and both actions are done in single places now rather than the former being scattered through emulation handlers. The part of do_cpu() being covered follows the changes to do_ri(). Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> ---
2007-10-16 17:43:26 +00:00
}
break;
#ifdef CONFIG_MIPS_FP_SUPPORT
MIPS: Handle COP3 Unusable exception as COP1X for FP emulation Our FP emulator is hardcoded for the MIPS IV FP instruction set and does not match the FP ISA with the general ISA. However for the few MIPS IV FP instructions that use the COP1X major opcode it relies on the Coprocessor Unusable exception to be delivered as a COP1 rather than COP3 exception. This includes indexed transfer (LDXC1, etc.) and FP multiply-accumulate (MADD.D, etc.) instructions. All the MIPS I, II, III and IV processors and some newer chips that do not implement the FPU use the COP3 exception however. Therefore I believe the kernel should follow and redirect any COP3 Unusable traps to the emulator unless an actual FPU part or core is present. This is a change that implements it. Any minor opcode encodings that are not recognised as valid FP instructions are rejected by the emulator and will result in a SIGILL signal being delivered as they currently do. We do not support vendor-specific coprocessor 3 implementations supported with MIPS I and MIPS II ISA processors; we never set CP0.Status.CU3. [Ralf: On MIPS IV processors the kernel always enables the XX bit which replaces the CU3 bit off earlier architecture revisions.] If matching between the CPU and the FPU ISA is considered required one day, this can still be done in the emulator itself. I think the CpU exception dispatcher is not the right place to do this anyway, as there are further differences between MIPS I, MIPS II, MIPS III, MIPS IV and MIPS32 FP ISAs. Corresponding explanation of this implementation is included within the change itself. Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/project/linux-mips/list/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2012-03-06 20:28:54 +00:00
case 3:
/*
* The COP3 opcode space and consequently the CP0.Status.CU3
* bit and the CP0.Cause.CE=3 encoding have been removed as
* of the MIPS III ISA. From the MIPS IV and MIPS32r2 ISAs
* up the space has been reused for COP1X instructions, that
* are enabled by the CP0.Status.CU1 bit and consequently
* use the CP0.Cause.CE=1 encoding for Coprocessor Unusable
* exceptions. Some FPU-less processors that implement one
* of these ISAs however use this code erroneously for COP1X
* instructions. Therefore we redirect this trap to the FP
* emulator too.
MIPS: Handle COP3 Unusable exception as COP1X for FP emulation Our FP emulator is hardcoded for the MIPS IV FP instruction set and does not match the FP ISA with the general ISA. However for the few MIPS IV FP instructions that use the COP1X major opcode it relies on the Coprocessor Unusable exception to be delivered as a COP1 rather than COP3 exception. This includes indexed transfer (LDXC1, etc.) and FP multiply-accumulate (MADD.D, etc.) instructions. All the MIPS I, II, III and IV processors and some newer chips that do not implement the FPU use the COP3 exception however. Therefore I believe the kernel should follow and redirect any COP3 Unusable traps to the emulator unless an actual FPU part or core is present. This is a change that implements it. Any minor opcode encodings that are not recognised as valid FP instructions are rejected by the emulator and will result in a SIGILL signal being delivered as they currently do. We do not support vendor-specific coprocessor 3 implementations supported with MIPS I and MIPS II ISA processors; we never set CP0.Status.CU3. [Ralf: On MIPS IV processors the kernel always enables the XX bit which replaces the CU3 bit off earlier architecture revisions.] If matching between the CPU and the FPU ISA is considered required one day, this can still be done in the emulator itself. I think the CpU exception dispatcher is not the right place to do this anyway, as there are further differences between MIPS I, MIPS II, MIPS III, MIPS IV and MIPS32 FP ISAs. Corresponding explanation of this implementation is included within the change itself. Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/project/linux-mips/list/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2012-03-06 20:28:54 +00:00
*/
if (raw_cpu_has_fpu || !cpu_has_mips_4_5_64_r2_r6) {
force_sig(SIGILL);
MIPS: Handle COP3 Unusable exception as COP1X for FP emulation Our FP emulator is hardcoded for the MIPS IV FP instruction set and does not match the FP ISA with the general ISA. However for the few MIPS IV FP instructions that use the COP1X major opcode it relies on the Coprocessor Unusable exception to be delivered as a COP1 rather than COP3 exception. This includes indexed transfer (LDXC1, etc.) and FP multiply-accumulate (MADD.D, etc.) instructions. All the MIPS I, II, III and IV processors and some newer chips that do not implement the FPU use the COP3 exception however. Therefore I believe the kernel should follow and redirect any COP3 Unusable traps to the emulator unless an actual FPU part or core is present. This is a change that implements it. Any minor opcode encodings that are not recognised as valid FP instructions are rejected by the emulator and will result in a SIGILL signal being delivered as they currently do. We do not support vendor-specific coprocessor 3 implementations supported with MIPS I and MIPS II ISA processors; we never set CP0.Status.CU3. [Ralf: On MIPS IV processors the kernel always enables the XX bit which replaces the CU3 bit off earlier architecture revisions.] If matching between the CPU and the FPU ISA is considered required one day, this can still be done in the emulator itself. I think the CpU exception dispatcher is not the right place to do this anyway, as there are further differences between MIPS I, MIPS II, MIPS III, MIPS IV and MIPS32 FP ISAs. Corresponding explanation of this implementation is included within the change itself. Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/project/linux-mips/list/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2012-03-06 20:28:54 +00:00
break;
}
fallthrough;
case 1: {
void __user *fault_addr;
unsigned long fcr31;
int err, sig;
err = enable_restore_fp_context(0);
if (raw_cpu_has_fpu && !err)
break;
sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 0,
&fault_addr);
/*
* We can't allow the emulated instruction to leave
2016-10-28 07:21:03 +00:00
* any enabled Cause bits set in $fcr31.
*/
2016-10-28 07:21:03 +00:00
fcr31 = mask_fcr31_x(current->thread.fpu.fcr31);
current->thread.fpu.fcr31 &= ~fcr31;
/* Send a signal if required. */
if (!process_fpemu_return(sig, fault_addr, fcr31) && !err)
mt_ase_fp_affinity();
break;
}
#else /* CONFIG_MIPS_FP_SUPPORT */
case 1:
case 3:
force_sig(SIGILL);
break;
#endif /* CONFIG_MIPS_FP_SUPPORT */
case 2:
raw_notifier_call_chain(&cu2_chain, CU2_EXCEPTION, regs);
break;
}
exception_exit(prev_state);
}
MIPS: Clear [MSA]FPE CSR.Cause after notify_die() When handling floating point exceptions (FPEs) and MSA FPEs the Cause bits of the appropriate control and status register (FCSR for FPEs and MSACSR for MSA FPEs) are read and cleared before enabling interrupts, presumably so that it doesn't have to go through the pain of restoring those bits if the process is pre-empted, since writing those bits would cause another immediate exception while still in the kernel. The bits aren't normally ever restored again, since userland never expects to see them set. However for virtualisation it is necessary for the kernel to be able to restore these Cause bits, as the guest may have been interrupted in an FP exception handler but before it could read the Cause bits. This can be done by registering a die notifier, to get notified of the exception when such a value is restored, and if the PC was at the instruction which is used to restore the guest state, the handler can step over it and continue execution. The Cause bits can then remain set without causing further exceptions. For this to work safely a few changes are made: - __build_clear_fpe and __build_clear_msa_fpe no longer clear the Cause bits, and now return from exception level with interrupts disabled instead of enabled. - do_fpe() now clears the Cause bits and enables interrupts after notify_die() is called, so that the notifier can chose to return from exception without this happening. - do_msa_fpe() acts similarly, but now actually makes use of the second argument (msacsr) and calls notify_die() with the new DIE_MSAFP, allowing die notifiers to be informed of MSA FPEs too. Signed-off-by: James Hogan <james.hogan@imgtec.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
2014-12-02 13:44:13 +00:00
asmlinkage void do_msa_fpe(struct pt_regs *regs, unsigned int msacsr)
{
enum ctx_state prev_state;
prev_state = exception_enter();
current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
MIPS: Clear [MSA]FPE CSR.Cause after notify_die() When handling floating point exceptions (FPEs) and MSA FPEs the Cause bits of the appropriate control and status register (FCSR for FPEs and MSACSR for MSA FPEs) are read and cleared before enabling interrupts, presumably so that it doesn't have to go through the pain of restoring those bits if the process is pre-empted, since writing those bits would cause another immediate exception while still in the kernel. The bits aren't normally ever restored again, since userland never expects to see them set. However for virtualisation it is necessary for the kernel to be able to restore these Cause bits, as the guest may have been interrupted in an FP exception handler but before it could read the Cause bits. This can be done by registering a die notifier, to get notified of the exception when such a value is restored, and if the PC was at the instruction which is used to restore the guest state, the handler can step over it and continue execution. The Cause bits can then remain set without causing further exceptions. For this to work safely a few changes are made: - __build_clear_fpe and __build_clear_msa_fpe no longer clear the Cause bits, and now return from exception level with interrupts disabled instead of enabled. - do_fpe() now clears the Cause bits and enables interrupts after notify_die() is called, so that the notifier can chose to return from exception without this happening. - do_msa_fpe() acts similarly, but now actually makes use of the second argument (msacsr) and calls notify_die() with the new DIE_MSAFP, allowing die notifiers to be informed of MSA FPEs too. Signed-off-by: James Hogan <james.hogan@imgtec.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
2014-12-02 13:44:13 +00:00
if (notify_die(DIE_MSAFP, "MSA FP exception", regs, 0,
current->thread.trap_nr, SIGFPE) == NOTIFY_STOP)
MIPS: Clear [MSA]FPE CSR.Cause after notify_die() When handling floating point exceptions (FPEs) and MSA FPEs the Cause bits of the appropriate control and status register (FCSR for FPEs and MSACSR for MSA FPEs) are read and cleared before enabling interrupts, presumably so that it doesn't have to go through the pain of restoring those bits if the process is pre-empted, since writing those bits would cause another immediate exception while still in the kernel. The bits aren't normally ever restored again, since userland never expects to see them set. However for virtualisation it is necessary for the kernel to be able to restore these Cause bits, as the guest may have been interrupted in an FP exception handler but before it could read the Cause bits. This can be done by registering a die notifier, to get notified of the exception when such a value is restored, and if the PC was at the instruction which is used to restore the guest state, the handler can step over it and continue execution. The Cause bits can then remain set without causing further exceptions. For this to work safely a few changes are made: - __build_clear_fpe and __build_clear_msa_fpe no longer clear the Cause bits, and now return from exception level with interrupts disabled instead of enabled. - do_fpe() now clears the Cause bits and enables interrupts after notify_die() is called, so that the notifier can chose to return from exception without this happening. - do_msa_fpe() acts similarly, but now actually makes use of the second argument (msacsr) and calls notify_die() with the new DIE_MSAFP, allowing die notifiers to be informed of MSA FPEs too. Signed-off-by: James Hogan <james.hogan@imgtec.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
2014-12-02 13:44:13 +00:00
goto out;
/* Clear MSACSR.Cause before enabling interrupts */
write_msa_csr(msacsr & ~MSA_CSR_CAUSEF);
local_irq_enable();
die_if_kernel("do_msa_fpe invoked from kernel context!", regs);
force_sig(SIGFPE);
MIPS: Clear [MSA]FPE CSR.Cause after notify_die() When handling floating point exceptions (FPEs) and MSA FPEs the Cause bits of the appropriate control and status register (FCSR for FPEs and MSACSR for MSA FPEs) are read and cleared before enabling interrupts, presumably so that it doesn't have to go through the pain of restoring those bits if the process is pre-empted, since writing those bits would cause another immediate exception while still in the kernel. The bits aren't normally ever restored again, since userland never expects to see them set. However for virtualisation it is necessary for the kernel to be able to restore these Cause bits, as the guest may have been interrupted in an FP exception handler but before it could read the Cause bits. This can be done by registering a die notifier, to get notified of the exception when such a value is restored, and if the PC was at the instruction which is used to restore the guest state, the handler can step over it and continue execution. The Cause bits can then remain set without causing further exceptions. For this to work safely a few changes are made: - __build_clear_fpe and __build_clear_msa_fpe no longer clear the Cause bits, and now return from exception level with interrupts disabled instead of enabled. - do_fpe() now clears the Cause bits and enables interrupts after notify_die() is called, so that the notifier can chose to return from exception without this happening. - do_msa_fpe() acts similarly, but now actually makes use of the second argument (msacsr) and calls notify_die() with the new DIE_MSAFP, allowing die notifiers to be informed of MSA FPEs too. Signed-off-by: James Hogan <james.hogan@imgtec.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
2014-12-02 13:44:13 +00:00
out:
exception_exit(prev_state);
}
asmlinkage void do_msa(struct pt_regs *regs)
{
enum ctx_state prev_state;
int err;
prev_state = exception_enter();
if (!cpu_has_msa || test_thread_flag(TIF_32BIT_FPREGS)) {
force_sig(SIGILL);
goto out;
}
die_if_kernel("do_msa invoked from kernel context!", regs);
err = enable_restore_fp_context(1);
if (err)
force_sig(SIGILL);
out:
exception_exit(prev_state);
}
asmlinkage void do_mdmx(struct pt_regs *regs)
{
enum ctx_state prev_state;
prev_state = exception_enter();
force_sig(SIGILL);
exception_exit(prev_state);
}
/*
* Called with interrupts disabled.
*/
asmlinkage void do_watch(struct pt_regs *regs)
{
enum ctx_state prev_state;
prev_state = exception_enter();
/*
* Clear WP (bit 22) bit of cause register so we don't loop
* forever.
*/
clear_c0_cause(CAUSEF_WP);
/*
* If the current thread has the watch registers loaded, save
* their values and send SIGTRAP. Otherwise another thread
* left the registers set, clear them and continue.
*/
if (test_tsk_thread_flag(current, TIF_LOAD_WATCH)) {
mips_read_watch_registers();
local_irq_enable();
force_sig_fault(SIGTRAP, TRAP_HWBKPT, NULL);
} else {
mips_clear_watch_registers();
local_irq_enable();
}
exception_exit(prev_state);
}
asmlinkage void do_mcheck(struct pt_regs *regs)
{
int multi_match = regs->cp0_status & ST0_TS;
enum ctx_state prev_state;
prev_state = exception_enter();
show_regs(regs);
if (multi_match) {
dump_tlb_regs();
pr_info("\n");
dump_tlb_all();
}
show_code((void *)regs->cp0_epc, user_mode(regs));
/*
* Some chips may have other causes of machine check (e.g. SB1
* graduation timer)
*/
panic("Caught Machine Check exception - %scaused by multiple "
"matching entries in the TLB.",
(multi_match) ? "" : "not ");
}
asmlinkage void do_mt(struct pt_regs *regs)
{
int subcode;
subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
>> VPECONTROL_EXCPT_SHIFT;
switch (subcode) {
case 0:
printk(KERN_DEBUG "Thread Underflow\n");
break;
case 1:
printk(KERN_DEBUG "Thread Overflow\n");
break;
case 2:
printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
break;
case 3:
printk(KERN_DEBUG "Gating Storage Exception\n");
break;
case 4:
printk(KERN_DEBUG "YIELD Scheduler Exception\n");
break;
case 5:
printk(KERN_DEBUG "Gating Storage Scheduler Exception\n");
break;
default:
printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
subcode);
break;
}
die_if_kernel("MIPS MT Thread exception in kernel", regs);
force_sig(SIGILL);
}
asmlinkage void do_dsp(struct pt_regs *regs)
{
if (cpu_has_dsp)
panic("Unexpected DSP exception");
force_sig(SIGILL);
}
asmlinkage void do_reserved(struct pt_regs *regs)
{
/*
* Game over - no way to handle this if it ever occurs. Most probably
* caused by a new unknown cpu type or after another deadly
* hard/software error.
*/
show_regs(regs);
panic("Caught reserved exception %ld - should not happen.",
(regs->cp0_cause & 0x7f) >> 2);
}
static int __initdata l1parity = 1;
static int __init nol1parity(char *s)
{
l1parity = 0;
return 1;
}
__setup("nol1par", nol1parity);
static int __initdata l2parity = 1;
static int __init nol2parity(char *s)
{
l2parity = 0;
return 1;
}
__setup("nol2par", nol2parity);
/*
* Some MIPS CPUs can enable/disable for cache parity detection, but do
* it different ways.
*/
static inline __init void parity_protection_init(void)
{
#define ERRCTL_PE 0x80000000
#define ERRCTL_L2P 0x00800000
if (mips_cm_revision() >= CM_REV_CM3) {
ulong gcr_ectl, cp0_ectl;
/*
* With CM3 systems we need to ensure that the L1 & L2
* parity enables are set to the same value, since this
* is presumed by the hardware engineers.
*
* If the user disabled either of L1 or L2 ECC checking,
* disable both.
*/
l1parity &= l2parity;
l2parity &= l1parity;
/* Probe L1 ECC support */
cp0_ectl = read_c0_ecc();
write_c0_ecc(cp0_ectl | ERRCTL_PE);
back_to_back_c0_hazard();
cp0_ectl = read_c0_ecc();
/* Probe L2 ECC support */
gcr_ectl = read_gcr_err_control();
MIPS: CM: Use BIT/GENMASK for register fields, order & drop shifts There's no reason for us not to use BIT() & GENMASK() in asm/mips-cm.h when declaring macros corresponding to register fields. This patch modifies our definitions to do so. The *_SHF definitions are removed entirely - they duplicate information found in the masks, are infrequently used & can be replaced with use of __ffs() where needed. The *_MSK definitions then lose their _MSK suffix which is now somewhat redundant, and users are modified to match. The field definitions are moved to follow the appropriate register's accessor functions, which helps to keep the field definitions in order & to find the appropriate fields for a given register. Whilst here a comment is added describing each register & including its name, which is helpful both for linking the register back to hardware documentation & for grepping purposes. This also cleans up a couple of issues that became obvious as a result of making the changes described above: - We previously had definitions for GCR_Cx_RESET_EXT_BASE & a phony copy of that named GCR_RESET_EXT_BASE - a register which does not exist. The bad definitions were added by commit 497e803ebf98 ("MIPS: smp-cps: Ensure secondary cores start with EVA disabled") and made use of from boot_core(), which is now modified to use the GCR_Cx_RESET_EXT_BASE definitions. - We had a typo in CM_GCR_ERROR_CAUSE_ERRINGO_MSK - we now correctly define this as inFo rather than inGo. Now that we don't duplicate field information between _SHF & _MSK definitions, and keep the fields next to the register accessors, it will be much easier to spot & prevent any similar oddities being introduced in the future. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Acked-by: Thomas Gleixner <tglx@linutronix.de Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/17001/ Patchwork: https://patchwork.linux-mips.org/patch/17216/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-08-13 02:49:27 +00:00
if (!(gcr_ectl & CM_GCR_ERR_CONTROL_L2_ECC_SUPPORT) ||
!(cp0_ectl & ERRCTL_PE)) {
/*
* One of L1 or L2 ECC checking isn't supported,
* so we cannot enable either.
*/
l1parity = l2parity = 0;
}
/* Configure L1 ECC checking */
if (l1parity)
cp0_ectl |= ERRCTL_PE;
else
cp0_ectl &= ~ERRCTL_PE;
write_c0_ecc(cp0_ectl);
back_to_back_c0_hazard();
WARN_ON(!!(read_c0_ecc() & ERRCTL_PE) != l1parity);
/* Configure L2 ECC checking */
if (l2parity)
MIPS: CM: Use BIT/GENMASK for register fields, order & drop shifts There's no reason for us not to use BIT() & GENMASK() in asm/mips-cm.h when declaring macros corresponding to register fields. This patch modifies our definitions to do so. The *_SHF definitions are removed entirely - they duplicate information found in the masks, are infrequently used & can be replaced with use of __ffs() where needed. The *_MSK definitions then lose their _MSK suffix which is now somewhat redundant, and users are modified to match. The field definitions are moved to follow the appropriate register's accessor functions, which helps to keep the field definitions in order & to find the appropriate fields for a given register. Whilst here a comment is added describing each register & including its name, which is helpful both for linking the register back to hardware documentation & for grepping purposes. This also cleans up a couple of issues that became obvious as a result of making the changes described above: - We previously had definitions for GCR_Cx_RESET_EXT_BASE & a phony copy of that named GCR_RESET_EXT_BASE - a register which does not exist. The bad definitions were added by commit 497e803ebf98 ("MIPS: smp-cps: Ensure secondary cores start with EVA disabled") and made use of from boot_core(), which is now modified to use the GCR_Cx_RESET_EXT_BASE definitions. - We had a typo in CM_GCR_ERROR_CAUSE_ERRINGO_MSK - we now correctly define this as inFo rather than inGo. Now that we don't duplicate field information between _SHF & _MSK definitions, and keep the fields next to the register accessors, it will be much easier to spot & prevent any similar oddities being introduced in the future. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Acked-by: Thomas Gleixner <tglx@linutronix.de Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/17001/ Patchwork: https://patchwork.linux-mips.org/patch/17216/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-08-13 02:49:27 +00:00
gcr_ectl |= CM_GCR_ERR_CONTROL_L2_ECC_EN;
else
MIPS: CM: Use BIT/GENMASK for register fields, order & drop shifts There's no reason for us not to use BIT() & GENMASK() in asm/mips-cm.h when declaring macros corresponding to register fields. This patch modifies our definitions to do so. The *_SHF definitions are removed entirely - they duplicate information found in the masks, are infrequently used & can be replaced with use of __ffs() where needed. The *_MSK definitions then lose their _MSK suffix which is now somewhat redundant, and users are modified to match. The field definitions are moved to follow the appropriate register's accessor functions, which helps to keep the field definitions in order & to find the appropriate fields for a given register. Whilst here a comment is added describing each register & including its name, which is helpful both for linking the register back to hardware documentation & for grepping purposes. This also cleans up a couple of issues that became obvious as a result of making the changes described above: - We previously had definitions for GCR_Cx_RESET_EXT_BASE & a phony copy of that named GCR_RESET_EXT_BASE - a register which does not exist. The bad definitions were added by commit 497e803ebf98 ("MIPS: smp-cps: Ensure secondary cores start with EVA disabled") and made use of from boot_core(), which is now modified to use the GCR_Cx_RESET_EXT_BASE definitions. - We had a typo in CM_GCR_ERROR_CAUSE_ERRINGO_MSK - we now correctly define this as inFo rather than inGo. Now that we don't duplicate field information between _SHF & _MSK definitions, and keep the fields next to the register accessors, it will be much easier to spot & prevent any similar oddities being introduced in the future. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Acked-by: Thomas Gleixner <tglx@linutronix.de Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/17001/ Patchwork: https://patchwork.linux-mips.org/patch/17216/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-08-13 02:49:27 +00:00
gcr_ectl &= ~CM_GCR_ERR_CONTROL_L2_ECC_EN;
write_gcr_err_control(gcr_ectl);
gcr_ectl = read_gcr_err_control();
MIPS: CM: Use BIT/GENMASK for register fields, order & drop shifts There's no reason for us not to use BIT() & GENMASK() in asm/mips-cm.h when declaring macros corresponding to register fields. This patch modifies our definitions to do so. The *_SHF definitions are removed entirely - they duplicate information found in the masks, are infrequently used & can be replaced with use of __ffs() where needed. The *_MSK definitions then lose their _MSK suffix which is now somewhat redundant, and users are modified to match. The field definitions are moved to follow the appropriate register's accessor functions, which helps to keep the field definitions in order & to find the appropriate fields for a given register. Whilst here a comment is added describing each register & including its name, which is helpful both for linking the register back to hardware documentation & for grepping purposes. This also cleans up a couple of issues that became obvious as a result of making the changes described above: - We previously had definitions for GCR_Cx_RESET_EXT_BASE & a phony copy of that named GCR_RESET_EXT_BASE - a register which does not exist. The bad definitions were added by commit 497e803ebf98 ("MIPS: smp-cps: Ensure secondary cores start with EVA disabled") and made use of from boot_core(), which is now modified to use the GCR_Cx_RESET_EXT_BASE definitions. - We had a typo in CM_GCR_ERROR_CAUSE_ERRINGO_MSK - we now correctly define this as inFo rather than inGo. Now that we don't duplicate field information between _SHF & _MSK definitions, and keep the fields next to the register accessors, it will be much easier to spot & prevent any similar oddities being introduced in the future. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Acked-by: Thomas Gleixner <tglx@linutronix.de Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/17001/ Patchwork: https://patchwork.linux-mips.org/patch/17216/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-08-13 02:49:27 +00:00
gcr_ectl &= CM_GCR_ERR_CONTROL_L2_ECC_EN;
WARN_ON(!!gcr_ectl != l2parity);
pr_info("Cache parity protection %sabled\n",
l1parity ? "en" : "dis");
return;
}
switch (current_cpu_type()) {
case CPU_24K:
case CPU_34K:
case CPU_74K:
case CPU_1004K:
case CPU_1074K:
case CPU_INTERAPTIV:
case CPU_PROAPTIV:
case CPU_P5600:
case CPU_QEMU_GENERIC:
case CPU_P6600:
{
unsigned long errctl;
unsigned int l1parity_present, l2parity_present;
errctl = read_c0_ecc();
errctl &= ~(ERRCTL_PE|ERRCTL_L2P);
/* probe L1 parity support */
write_c0_ecc(errctl | ERRCTL_PE);
back_to_back_c0_hazard();
l1parity_present = (read_c0_ecc() & ERRCTL_PE);
/* probe L2 parity support */
write_c0_ecc(errctl|ERRCTL_L2P);
back_to_back_c0_hazard();
l2parity_present = (read_c0_ecc() & ERRCTL_L2P);
if (l1parity_present && l2parity_present) {
if (l1parity)
errctl |= ERRCTL_PE;
if (l1parity ^ l2parity)
errctl |= ERRCTL_L2P;
} else if (l1parity_present) {
if (l1parity)
errctl |= ERRCTL_PE;
} else if (l2parity_present) {
if (l2parity)
errctl |= ERRCTL_L2P;
} else {
/* No parity available */
}
printk(KERN_INFO "Writing ErrCtl register=%08lx\n", errctl);
write_c0_ecc(errctl);
back_to_back_c0_hazard();
errctl = read_c0_ecc();
printk(KERN_INFO "Readback ErrCtl register=%08lx\n", errctl);
if (l1parity_present)
printk(KERN_INFO "Cache parity protection %sabled\n",
(errctl & ERRCTL_PE) ? "en" : "dis");
if (l2parity_present) {
if (l1parity_present && l1parity)
errctl ^= ERRCTL_L2P;
printk(KERN_INFO "L2 cache parity protection %sabled\n",
(errctl & ERRCTL_L2P) ? "en" : "dis");
}
}
break;
case CPU_5KC:
case CPU_5KE:
case CPU_LOONGSON32:
write_c0_ecc(0x80000000);
back_to_back_c0_hazard();
/* Set the PE bit (bit 31) in the c0_errctl register. */
printk(KERN_INFO "Cache parity protection %sabled\n",
(read_c0_ecc() & 0x80000000) ? "en" : "dis");
break;
case CPU_20KC:
case CPU_25KF:
/* Clear the DE bit (bit 16) in the c0_status register. */
printk(KERN_INFO "Enable cache parity protection for "
"MIPS 20KC/25KF CPUs.\n");
clear_c0_status(ST0_DE);
break;
default:
break;
}
}
asmlinkage void cache_parity_error(void)
{
const int field = 2 * sizeof(unsigned long);
unsigned int reg_val;
/* For the moment, report the problem and hang. */
printk("Cache error exception:\n");
printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
reg_val = read_c0_cacheerr();
printk("c0_cacheerr == %08x\n", reg_val);
printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
reg_val & (1<<30) ? "secondary" : "primary",
reg_val & (1<<31) ? "data" : "insn");
if ((cpu_has_mips_r2_r6) &&
((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_MIPS)) {
pr_err("Error bits: %s%s%s%s%s%s%s%s\n",
reg_val & (1<<29) ? "ED " : "",
reg_val & (1<<28) ? "ET " : "",
reg_val & (1<<27) ? "ES " : "",
reg_val & (1<<26) ? "EE " : "",
reg_val & (1<<25) ? "EB " : "",
reg_val & (1<<24) ? "EI " : "",
reg_val & (1<<23) ? "E1 " : "",
reg_val & (1<<22) ? "E0 " : "");
} else {
pr_err("Error bits: %s%s%s%s%s%s%s\n",
reg_val & (1<<29) ? "ED " : "",
reg_val & (1<<28) ? "ET " : "",
reg_val & (1<<26) ? "EE " : "",
reg_val & (1<<25) ? "EB " : "",
reg_val & (1<<24) ? "EI " : "",
reg_val & (1<<23) ? "E1 " : "",
reg_val & (1<<22) ? "E0 " : "");
}
printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
#if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
if (reg_val & (1<<22))
printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());
if (reg_val & (1<<23))
printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
#endif
panic("Can't handle the cache error!");
}
asmlinkage void do_ftlb(void)
{
const int field = 2 * sizeof(unsigned long);
unsigned int reg_val;
/* For the moment, report the problem and hang. */
if ((cpu_has_mips_r2_r6) &&
(((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_MIPS) ||
((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_LOONGSON))) {
pr_err("FTLB error exception, cp0_ecc=0x%08x:\n",
read_c0_ecc());
pr_err("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
reg_val = read_c0_cacheerr();
pr_err("c0_cacheerr == %08x\n", reg_val);
if ((reg_val & 0xc0000000) == 0xc0000000) {
pr_err("Decoded c0_cacheerr: FTLB parity error\n");
} else {
pr_err("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
reg_val & (1<<30) ? "secondary" : "primary",
reg_val & (1<<31) ? "data" : "insn");
}
} else {
pr_err("FTLB error exception\n");
}
/* Just print the cacheerr bits for now */
cache_parity_error();
}
MIPS: handle Loongson-specific GSExc exception Newer Loongson cores (Loongson-3A R2 and newer) use the implementation-dependent ExcCode 16 to signal Loongson-specific exceptions. The extended cause is put in the non-standard CP0.Diag1 register which is CP0 Register 22 Select 1, called GSCause in Loongson manuals. Inside is an exception code bitfield called GSExcCode, only codes 0 to 6 inclusive are documented (so far, in the Loongson 3A3000 User Manual, Volume 2). During experiments, it was found that some undocumented unprivileged instructions can trigger the also-undocumented GSExcCode 8 on Loongson 3A4000. Processor state is not corrupted, but we cannot continue without further knowledge, and Loongson is not providing that information as of this writing. So we send SIGILL on seeing this exception code to thwart easy local DoS attacks. Other exception codes are made fatal, partly because of insufficient knowledge, also partly because they are not as easily reproduced. None of them are encountered in the wild with upstream kernels and userspace so far. Some older cores (Loongson-3A1000 and Loongson-3B1500) have ExcCode 16 too, but the semantic is equivalent to GSExcCode 0. Because the respective manuals did not mention the CP0.Diag1 register or its read behavior, these cores are not covered in this patch, as MFC0 from non-existent CP0 registers is UNDEFINED according to the MIPS architecture spec. Reviewed-by: Huacai Chen <chenhc@lemote.com> Signed-off-by: WANG Xuerui <git@xen0n.name> Cc: Huacai Chen <chenhc@lemote.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2020-07-29 13:14:17 +00:00
asmlinkage void do_gsexc(struct pt_regs *regs, u32 diag1)
{
u32 exccode = (diag1 & LOONGSON_DIAG1_EXCCODE) >>
LOONGSON_DIAG1_EXCCODE_SHIFT;
enum ctx_state prev_state;
prev_state = exception_enter();
switch (exccode) {
case 0x08:
/* Undocumented exception, will trigger on certain
* also-undocumented instructions accessible from userspace.
* Processor state is not otherwise corrupted, but currently
* we don't know how to proceed. Maybe there is some
* undocumented control flag to enable the instructions?
*/
force_sig(SIGILL);
break;
default:
/* None of the other exceptions, documented or not, have
* further details given; none are encountered in the wild
* either. Panic in case some of them turn out to be fatal.
*/
show_regs(regs);
panic("Unhandled Loongson exception - GSCause = %08x", diag1);
}
exception_exit(prev_state);
}
/*
* SDBBP EJTAG debug exception handler.
* We skip the instruction and return to the next instruction.
*/
void ejtag_exception_handler(struct pt_regs *regs)
{
const int field = 2 * sizeof(unsigned long);
unsigned long depc, old_epc, old_ra;
unsigned int debug;
printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
depc = read_c0_depc();
debug = read_c0_debug();
printk(KERN_DEBUG "c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
if (debug & 0x80000000) {
/*
* In branch delay slot.
* We cheat a little bit here and use EPC to calculate the
* debug return address (DEPC). EPC is restored after the
* calculation.
*/
old_epc = regs->cp0_epc;
old_ra = regs->regs[31];
regs->cp0_epc = depc;
compute_return_epc(regs);
depc = regs->cp0_epc;
regs->cp0_epc = old_epc;
regs->regs[31] = old_ra;
} else
depc += 4;
write_c0_depc(depc);
#if 0
printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n");
write_c0_debug(debug | 0x100);
#endif
}
/*
* NMI exception handler.
* No lock; only written during early bootup by CPU 0.
*/
static RAW_NOTIFIER_HEAD(nmi_chain);
int register_nmi_notifier(struct notifier_block *nb)
{
return raw_notifier_chain_register(&nmi_chain, nb);
}
void __noreturn nmi_exception_handler(struct pt_regs *regs)
{
char str[100];
nmi_enter();
raw_notifier_call_chain(&nmi_chain, 0, regs);
bust_spinlocks(1);
snprintf(str, 100, "CPU%d NMI taken, CP0_EPC=%lx\n",
smp_processor_id(), regs->cp0_epc);
regs->cp0_epc = read_c0_errorepc();
die(str, regs);
nmi_exit();
}
unsigned long ebase;
EXPORT_SYMBOL_GPL(ebase);
unsigned long exception_handlers[32];
unsigned long vi_handlers[64];
void reserve_exception_space(phys_addr_t addr, unsigned long size)
{
memblock_reserve(addr, size);
}
void __init *set_except_vector(int n, void *addr)
{
unsigned long handler = (unsigned long) addr;
unsigned long old_handler;
#ifdef CONFIG_CPU_MICROMIPS
/*
* Only the TLB handlers are cache aligned with an even
* address. All other handlers are on an odd address and
* require no modification. Otherwise, MIPS32 mode will
* be entered when handling any TLB exceptions. That
* would be bad...since we must stay in microMIPS mode.
*/
if (!(handler & 0x1))
handler |= 1;
#endif
old_handler = xchg(&exception_handlers[n], handler);
if (n == 0 && cpu_has_divec) {
#ifdef CONFIG_CPU_MICROMIPS
unsigned long jump_mask = ~((1 << 27) - 1);
#else
unsigned long jump_mask = ~((1 << 28) - 1);
#endif
u32 *buf = (u32 *)(ebase + 0x200);
unsigned int k0 = 26;
if ((handler & jump_mask) == ((ebase + 0x200) & jump_mask)) {
uasm_i_j(&buf, handler & ~jump_mask);
uasm_i_nop(&buf);
} else {
UASM_i_LA(&buf, k0, handler);
uasm_i_jr(&buf, k0);
uasm_i_nop(&buf);
}
local_flush_icache_range(ebase + 0x200, (unsigned long)buf);
}
return (void *)old_handler;
}
MIPS: Make tlb exception handler definitions and declarations match. The code was written as it is because it's more expressive, a bit easier. But it's always been dirty, if not a bug. But we can't cheat with LTO compilers, so this results in: [...] LDFINAL vmlinux.o In file included from arch/mips/kernel/topology.c:604:0, from arch/mips/kernel/time.c:212, from arch/mips/kernel/syscall.c:300, from arch/mips/kernel/signal.c:853, from arch/mips/kernel/setup.c:1030, from arch/mips/kernel/reset.c:354, from arch/mips/kernel/ptrace.c:562, from arch/mips/kernel/process.c:770, from arch/mips/kernel/irq.c:350, from arch/mips/kernel/branch.c:321, from arch/mips/kernel/cpu-probe.c:1370, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/thread_info.h:345, from arch/mips/sgi-ip22/ip22-gio.c:660, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/sgialib.h:219, from arch/mips/sgi-ip22/ip22-reset.c:224, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/paccess.h:116, from arch/mips/sgi-ip22/ip22-nvram.c:334, from include/linux/kernel_stat.h:79, from arch/mips/sgi-ip22/ip22-int.c:592, from arch/mips/sgi-ip22/ip22-hpc.c:470, from arch/mips/sgi-ip22/ip22-mc.c:135, from init/init_task.c:54, from init/calibrate.c:744, from init/noinitramfs.c:62, from init/do_mounts.c:573, from init/version.c:1009, from init/main.c:777, from :729: arch/mips/kernel/traps.c:63:49: error: variable ‘handle_tlbl’ redeclared as function In file included from arch/mips/mm/page.c:310:0, from arch/mips/mm/mmap.c:208, from arch/mips/mm/init.c:641, from arch/mips/mm/gup.c:811, from arch/mips/mm/fault.c:659, from include/linux/module.h:682, from arch/mips/mm/dma-default.c:161, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/thread_info.h:397, from arch/mips/kernel/i8253.c:538, from arch/mips/kernel/proc.c:145, from arch/mips/kernel/irq_cpu.c:129, from arch/mips/kernel/i8259.c:229, from include/uapi/linux/elf.h:251, from arch/mips/kernel/mips_ksyms.c:129, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/time.h:50, from arch/mips/kernel/cevt-r4k.c:90, from arch/mips/kernel/vdso.c:136, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/thread_info.h:351, from arch/mips/kernel/unaligned.c:809, from arch/mips/kernel/traps.c:1720, from arch/mips/kernel/topology.c:684, from arch/mips/kernel/time.c:212, from arch/mips/kernel/syscall.c:300, from arch/mips/kernel/signal.c:853, from arch/mips/kernel/setup.c:1030, from arch/mips/kernel/reset.c:354, from arch/mips/kernel/ptrace.c:562, from arch/mips/kernel/process.c:770, from arch/mips/kernel/irq.c:350, from arch/mips/kernel/branch.c:321, from arch/mips/kernel/cpu-probe.c:1370, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/thread_info.h:345, from arch/mips/sgi-ip22/ip22-gio.c:660, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/sgialib.h:219, from arch/mips/sgi-ip22/ip22-reset.c:224, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/paccess.h:116, from arch/mips/sgi-ip22/ip22-nvram.c:334, from include/linux/kernel_stat.h:79, from arch/mips/sgi-ip22/ip22-int.c:592, from arch/mips/sgi-ip22/ip22-hpc.c:470, from arch/mips/sgi-ip22/ip22-mc.c:135, from init/init_task.c:54, from init/calibrate.c:744, from init/noinitramfs.c:62, from init/do_mounts.c:573, from init/version.c:1009, from init/main.c:777, from :729: arch/mips/mm/tlbex.c:1448:5: note: previously declared here In file included from arch/mips/kernel/topology.c:604:0, from arch/mips/kernel/time.c:212, from arch/mips/kernel/syscall.c:300, from arch/mips/kernel/signal.c:853, from arch/mips/kernel/setup.c:1030, from arch/mips/kernel/reset.c:354, from arch/mips/kernel/ptrace.c:562, from arch/mips/kernel/process.c:770, from arch/mips/kernel/irq.c:350, from arch/mips/kernel/branch.c:321, from arch/mips/kernel/cpu-probe.c:1370, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/thread_info.h:345, from arch/mips/sgi-ip22/ip22-gio.c:660, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/sgialib.h:219, from arch/mips/sgi-ip22/ip22-reset.c:224, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/paccess.h:116, from arch/mips/sgi-ip22/ip22-nvram.c:334, from include/linux/kernel_stat.h:79, from arch/mips/sgi-ip22/ip22-int.c:592, from arch/mips/sgi-ip22/ip22-hpc.c:470, from arch/mips/sgi-ip22/ip22-mc.c:135, from init/init_task.c:54, from init/calibrate.c:744, from init/noinitramfs.c:62, from init/do_mounts.c:573, from init/version.c:1009, from init/main.c:777, from :729: arch/mips/kernel/traps.c:62:49: error: variable ‘handle_tlbm’ redeclared as function In file included from arch/mips/mm/page.c:310:0, from arch/mips/mm/mmap.c:208, from arch/mips/mm/init.c:641, from arch/mips/mm/gup.c:811, from arch/mips/mm/fault.c:659, from include/linux/module.h:682, from arch/mips/mm/dma-default.c:161, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/thread_info.h:397, from arch/mips/kernel/i8253.c:538, from arch/mips/kernel/proc.c:145, from arch/mips/kernel/irq_cpu.c:129, from arch/mips/kernel/i8259.c:229, from include/uapi/linux/elf.h:251, from arch/mips/kernel/mips_ksyms.c:129, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/time.h:50, from arch/mips/kernel/cevt-r4k.c:90, from arch/mips/kernel/vdso.c:136, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/thread_info.h:351, from arch/mips/kernel/unaligned.c:809, from arch/mips/kernel/traps.c:1720, from arch/mips/kernel/topology.c:684, from arch/mips/kernel/time.c:212, from arch/mips/kernel/syscall.c:300, from arch/mips/kernel/signal.c:853, from arch/mips/kernel/setup.c:1030, from arch/mips/kernel/reset.c:354, from arch/mips/kernel/ptrace.c:562, from arch/mips/kernel/process.c:770, from arch/mips/kernel/irq.c:350, from arch/mips/kernel/branch.c:321, from arch/mips/kernel/cpu-probe.c:1370, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/thread_info.h:345, from arch/mips/sgi-ip22/ip22-gio.c:660, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/sgialib.h:219, from arch/mips/sgi-ip22/ip22-reset.c:224, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/paccess.h:116, from arch/mips/sgi-ip22/ip22-nvram.c:334, from include/linux/kernel_stat.h:79, from arch/mips/sgi-ip22/ip22-int.c:592, from arch/mips/sgi-ip22/ip22-hpc.c:470, from arch/mips/sgi-ip22/ip22-mc.c:135, from init/init_task.c:54, from init/calibrate.c:744, from init/noinitramfs.c:62, from init/do_mounts.c:573, from init/version.c:1009, from init/main.c:777, from :729: arch/mips/mm/tlbex.c:1450:5: note: previously declared here In file included from arch/mips/kernel/topology.c:604:0, from arch/mips/kernel/time.c:212, from arch/mips/kernel/syscall.c:300, from arch/mips/kernel/signal.c:853, from arch/mips/kernel/setup.c:1030, from arch/mips/kernel/reset.c:354, from arch/mips/kernel/ptrace.c:562, from arch/mips/kernel/process.c:770, from arch/mips/kernel/irq.c:350, from arch/mips/kernel/branch.c:321, from arch/mips/kernel/cpu-probe.c:1370, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/thread_info.h:345, from arch/mips/sgi-ip22/ip22-gio.c:660, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/sgialib.h:219, from arch/mips/sgi-ip22/ip22-reset.c:224, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/paccess.h:116, from arch/mips/sgi-ip22/ip22-nvram.c:334, from include/linux/kernel_stat.h:79, from arch/mips/sgi-ip22/ip22-int.c:592, from arch/mips/sgi-ip22/ip22-hpc.c:470, from arch/mips/sgi-ip22/ip22-mc.c:135, from init/init_task.c:54, from init/calibrate.c:744, from init/noinitramfs.c:62, from init/do_mounts.c:573, from init/version.c:1009, from init/main.c:777, from :729: arch/mips/kernel/traps.c:64:49: error: variable ‘handle_tlbs’ redeclared as function In file included from arch/mips/mm/page.c:310:0, from arch/mips/mm/mmap.c:208, from arch/mips/mm/init.c:641, from arch/mips/mm/gup.c:811, from arch/mips/mm/fault.c:659, from include/linux/module.h:682, from arch/mips/mm/dma-default.c:161, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/thread_info.h:397, from arch/mips/kernel/i8253.c:538, from arch/mips/kernel/proc.c:145, from arch/mips/kernel/irq_cpu.c:129, from arch/mips/kernel/i8259.c:229, from include/uapi/linux/elf.h:251, from arch/mips/kernel/mips_ksyms.c:129, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/time.h:50, from arch/mips/kernel/cevt-r4k.c:90, from arch/mips/kernel/vdso.c:136, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/thread_info.h:351, from arch/mips/kernel/unaligned.c:809, from arch/mips/kernel/traps.c:1720, from arch/mips/kernel/topology.c:684, from arch/mips/kernel/time.c:212, from arch/mips/kernel/syscall.c:300, from arch/mips/kernel/signal.c:853, from arch/mips/kernel/setup.c:1030, from arch/mips/kernel/reset.c:354, from arch/mips/kernel/ptrace.c:562, from arch/mips/kernel/process.c:770, from arch/mips/kernel/irq.c:350, from arch/mips/kernel/branch.c:321, from arch/mips/kernel/cpu-probe.c:1370, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/thread_info.h:345, from arch/mips/sgi-ip22/ip22-gio.c:660, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/sgialib.h:219, from arch/mips/sgi-ip22/ip22-reset.c:224, from /fluff/home/ralf/src/linux/lto/linux-misc/arch/mips/include/asm/paccess.h:116, from arch/mips/sgi-ip22/ip22-nvram.c:334, from include/linux/kernel_stat.h:79, from arch/mips/sgi-ip22/ip22-int.c:592, from arch/mips/sgi-ip22/ip22-hpc.c:470, from arch/mips/sgi-ip22/ip22-mc.c:135, from init/init_task.c:54, from init/calibrate.c:744, from init/noinitramfs.c:62, from init/do_mounts.c:573, from init/version.c:1009, from init/main.c:777, from :729: arch/mips/mm/tlbex.c:1449:5: note: previously declared here lto1: fatal error: errors during merging of translation units compilation terminated. lto-wrapper: /usr/bin/mips-linux-gcc returned 1 exit status /usr/lib64/gcc/mips-linux/4.7.1/../../../../mips-linux/bin/ld: lto-wrapper failed collect2: error: ld returned 1 exit status make: *** [vmlinux] Error 1 Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-02-08 00:21:34 +00:00
static void do_default_vi(void)
{
show_regs(get_irq_regs());
panic("Caught unexpected vectored interrupt.");
}
static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
{
unsigned long handler;
unsigned long old_handler = vi_handlers[n];
int srssets = current_cpu_data.srsets;
u16 *h;
unsigned char *b;
BUG_ON(!cpu_has_veic && !cpu_has_vint);
if (addr == NULL) {
handler = (unsigned long) do_default_vi;
srs = 0;
} else
handler = (unsigned long) addr;
vi_handlers[n] = handler;
b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);
if (srs >= srssets)
panic("Shadow register set %d not supported", srs);
if (cpu_has_veic) {
if (board_bind_eic_interrupt)
board_bind_eic_interrupt(n, srs);
} else if (cpu_has_vint) {
/* SRSMap is only defined if shadow sets are implemented */
if (srssets > 1)
change_c0_srsmap(0xf << n*4, srs << n*4);
}
if (srs == 0) {
/*
* If no shadow set is selected then use the default handler
* that does normal register saving and standard interrupt exit
*/
extern const u8 except_vec_vi[], except_vec_vi_lui[];
extern const u8 except_vec_vi_ori[], except_vec_vi_end[];
extern const u8 rollback_except_vec_vi[];
const u8 *vec_start = using_rollback_handler() ?
rollback_except_vec_vi : except_vec_vi;
#if defined(CONFIG_CPU_MICROMIPS) || defined(CONFIG_CPU_BIG_ENDIAN)
const int lui_offset = except_vec_vi_lui - vec_start + 2;
const int ori_offset = except_vec_vi_ori - vec_start + 2;
#else
const int lui_offset = except_vec_vi_lui - vec_start;
const int ori_offset = except_vec_vi_ori - vec_start;
#endif
const int handler_len = except_vec_vi_end - vec_start;
if (handler_len > VECTORSPACING) {
/*
* Sigh... panicing won't help as the console
* is probably not configured :(
*/
panic("VECTORSPACING too small");
}
set_handler(((unsigned long)b - ebase), vec_start,
#ifdef CONFIG_CPU_MICROMIPS
(handler_len - 1));
#else
handler_len);
#endif
h = (u16 *)(b + lui_offset);
*h = (handler >> 16) & 0xffff;
h = (u16 *)(b + ori_offset);
*h = (handler & 0xffff);
local_flush_icache_range((unsigned long)b,
(unsigned long)(b+handler_len));
}
else {
/*
* In other cases jump directly to the interrupt handler. It
* is the handler's responsibility to save registers if required
* (eg hi/lo) and return from the exception using "eret".
*/
u32 insn;
h = (u16 *)b;
/* j handler */
#ifdef CONFIG_CPU_MICROMIPS
insn = 0xd4000000 | (((u32)handler & 0x07ffffff) >> 1);
#else
insn = 0x08000000 | (((u32)handler & 0x0fffffff) >> 2);
#endif
h[0] = (insn >> 16) & 0xffff;
h[1] = insn & 0xffff;
h[2] = 0;
h[3] = 0;
local_flush_icache_range((unsigned long)b,
(unsigned long)(b+8));
}
return (void *)old_handler;
}
void *set_vi_handler(int n, vi_handler_t addr)
{
return set_vi_srs_handler(n, addr, 0);
}
extern void tlb_init(void);
/*
* Timer interrupt
*/
int cp0_compare_irq;
EXPORT_SYMBOL_GPL(cp0_compare_irq);
int cp0_compare_irq_shift;
/*
* Performance counter IRQ or -1 if shared with timer
*/
int cp0_perfcount_irq;
EXPORT_SYMBOL_GPL(cp0_perfcount_irq);
/*
* Fast debug channel IRQ or -1 if not present
*/
int cp0_fdc_irq;
EXPORT_SYMBOL_GPL(cp0_fdc_irq);
MIPS: Delete __cpuinit/__CPUINIT usage from MIPS code commit 3747069b25e419f6b51395f48127e9812abc3596 upstream. The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. Note that some harmless section mismatch warnings may result, since notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c) and are flagged as __cpuinit -- so if we remove the __cpuinit from the arch specific callers, we will also get section mismatch warnings. As an intermediate step, we intend to turn the linux/init.h cpuinit related content into no-ops as early as possible, since that will get rid of these warnings. In any case, they are temporary and harmless. Here, we remove all the MIPS __cpuinit from C code and __CPUINIT from asm files. MIPS is interesting in this respect, because there are also uasm users hiding behind their own renamed versions of the __cpuinit macros. [1] https://lkml.org/lkml/2013/5/20/589 [ralf@linux-mips.org: Folded in Paul's followup fix.] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/5494/ Patchwork: https://patchwork.linux-mips.org/patch/5495/ Patchwork: https://patchwork.linux-mips.org/patch/5509/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-06-18 13:38:59 +00:00
static int noulri;
static int __init ulri_disable(char *s)
{
pr_info("Disabling ulri\n");
noulri = 1;
return 1;
}
__setup("noulri", ulri_disable);
/* configure STATUS register */
static void configure_status(void)
{
/*
* Disable coprocessors and select 32-bit or 64-bit addressing
* and the 16/32 or 32/32 FPR register model. Reset the BEV
* flag that some firmware may have left set and the TS bit (for
* IP27). Set XX for ISA IV code to work.
*/
unsigned int status_set = ST0_KERNEL_CUMASK;
#ifdef CONFIG_64BIT
status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
#endif
if (current_cpu_data.isa_level & MIPS_CPU_ISA_IV)
status_set |= ST0_XX;
if (cpu_has_dsp)
status_set |= ST0_MX;
change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
status_set);
MIPS: Add missing EHB in mtc0 -> mfc0 sequence for DSPen This resolves the hazard between the mtc0 in the change_c0_status() and the mfc0 in configure_exception_vector(). Without resolving this hazard configure_exception_vector() could read an old value and would restore this old value again. This would revert the changes change_c0_status() did. I checked this by printing out the read_c0_status() at the end of per_cpu_trap_init() and the ST0_MX is not set without this patch. The hazard is documented in the MIPS Architecture Reference Manual Vol. III: MIPS32/microMIPS32 Privileged Resource Architecture (MD00088), rev 6.03 table 8.1 which includes: Producer | Consumer | Hazard ----------|----------|---------------------------- mtc0 | mfc0 | any coprocessor 0 register I saw this hazard on an Atheros AR9344 rev 2 SoC with a MIPS 74Kc CPU. There the change_c0_status() function would activate the DSPen by setting ST0_MX in the c0_status register. This was reverted and then the system got a DSP exception when the DSP registers were saved in save_dsp() in the first process switch. The crash looks like this: [ 0.089999] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes, linear) [ 0.097796] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes, linear) [ 0.107070] Kernel panic - not syncing: Unexpected DSP exception [ 0.113470] Rebooting in 1 seconds.. We saw this problem in OpenWrt only on the MIPS 74Kc based Atheros SoCs, not on the 24Kc based SoCs. We only saw it with kernel 5.4 not with kernel 4.19, in addition we had to use GCC 8.4 or 9.X, with GCC 8.3 it did not happen. In the kernel I bisected this problem to commit 9012d011660e ("compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING"), but when this was reverted it also happened after commit 172dcd935c34b ("MIPS: Always allocate exception vector for MIPSr2+"). Commit 0b24cae4d535 ("MIPS: Add missing EHB in mtc0 -> mfc0 sequence.") does similar changes to a different file. I am not sure if there are more places affected by this problem. Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de> Cc: <stable@vger.kernel.org> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2020-07-02 22:53:34 +00:00
back_to_back_c0_hazard();
}
unsigned int hwrena;
EXPORT_SYMBOL_GPL(hwrena);
/* configure HWRENA register */
static void configure_hwrena(void)
{
hwrena = cpu_hwrena_impl_bits;
if (cpu_has_mips_r2_r6)
hwrena |= MIPS_HWRENA_CPUNUM |
MIPS_HWRENA_SYNCISTEP |
MIPS_HWRENA_CC |
MIPS_HWRENA_CCRES;
if (!noulri && cpu_has_userlocal)
hwrena |= MIPS_HWRENA_ULR;
if (hwrena)
write_c0_hwrena(hwrena);
}
static void configure_exception_vector(void)
{
if (cpu_has_mips_r2_r6) {
unsigned long sr = set_c0_status(ST0_BEV);
MIPS: traps: Ensure full EBase is written On CPUs which support the EBase WG (write gate) flag, the most significant bits of the exception base can be changed. Firmware running on a VP(E) using MIPS rproc may change EBase to point into the user segment where the firmware is located such that it can service interrupts. When control is transferred back to the kernel the EBase must be switched back into the kernel segment, such that the kernel's exception vectors are used. Similarly when vectored interrupts (vint) or vectored external interrupt controllers (veic) are enabled an exception vector is allocated from bootmem, and written to the EBase register. Due to the WG flag being clear, only bits 29:12 will be written. Asside from the rproc case above this is normally fine (as it will usually be a low allocation within the KSeg0 range, however when Enhanced Virtual Addressing (EVA) is enabled the allocation may be outside of the traditional KSeg0/KSeg1 address range, resulting in the wrong EBase being written. Correct both cases (configure_exception_vector() for the boot CPU, and per_cpu_trap_init() for secondary CPUs) to write EBase with the WG flag first if supported. On the Malta EVA configuration, KSeg0 is mapped to physical address 0, and memory is allocated from the KUSeg segment which is mapped to physical address 0x80000000, which physically aliases the RAM at 0. This only worked due to the exception base address aliasing the same underlying RAM that was written to & cache flushed, and due to flush_icache_range() going beyond the call of duty and flushing from the L2 cache too (due to the differing physical addresses). Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14150/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-09-01 16:30:09 +00:00
/* If available, use WG to set top bits of EBASE */
if (cpu_has_ebase_wg) {
#ifdef CONFIG_64BIT
write_c0_ebase_64(ebase | MIPS_EBASE_WG);
#else
write_c0_ebase(ebase | MIPS_EBASE_WG);
#endif
}
write_c0_ebase(ebase);
write_c0_status(sr);
}
if (cpu_has_veic || cpu_has_vint) {
/* Setting vector spacing enables EI/VI mode */
change_c0_intctl(0x3e0, VECTORSPACING);
}
if (cpu_has_divec) {
if (cpu_has_mipsmt) {
unsigned int vpflags = dvpe();
set_c0_cause(CAUSEF_IV);
evpe(vpflags);
} else
set_c0_cause(CAUSEF_IV);
}
}
void per_cpu_trap_init(bool is_boot_cpu)
{
unsigned int cpu = smp_processor_id();
configure_status();
configure_hwrena();
configure_exception_vector();
/*
* Before R2 both interrupt numbers were fixed to 7, so on R2 only:
*
* o read IntCtl.IPTI to determine the timer interrupt
* o read IntCtl.IPPCI to determine the performance counter interrupt
* o read IntCtl.IPFDC to determine the fast debug channel interrupt
*/
if (cpu_has_mips_r2_r6) {
cp0_compare_irq_shift = CAUSEB_TI - CAUSEB_IP;
cp0_compare_irq = (read_c0_intctl() >> INTCTLB_IPTI) & 7;
cp0_perfcount_irq = (read_c0_intctl() >> INTCTLB_IPPCI) & 7;
cp0_fdc_irq = (read_c0_intctl() >> INTCTLB_IPFDC) & 7;
if (!cp0_fdc_irq)
cp0_fdc_irq = -1;
} else {
cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
cp0_compare_irq_shift = CP0_LEGACY_PERFCNT_IRQ;
cp0_perfcount_irq = -1;
cp0_fdc_irq = -1;
}
MIPS: MemoryMapID (MMID) Support Introduce support for using MemoryMapIDs (MMIDs) as an alternative to Address Space IDs (ASIDs). The major difference between the two is that MMIDs are global - ie. an MMID uniquely identifies an address space across all coherent CPUs. In contrast ASIDs are non-global per-CPU IDs, wherein each address space is allocated a separate ASID for each CPU upon which it is used. This global namespace allows a new GINVT instruction be used to globally invalidate TLB entries associated with a particular MMID across all coherent CPUs in the system, removing the need for IPIs to invalidate entries with separate ASIDs on each CPU. The allocation scheme used here is largely borrowed from arm64 (see arch/arm64/mm/context.c). In essence we maintain a bitmap to track available MMIDs, and MMIDs in active use at the time of a rollover to a new MMID version are preserved in the new version. The allocation scheme requires efficient 64 bit atomics in order to perform reasonably, so this support depends upon CONFIG_GENERIC_ATOMIC64=n (ie. currently it will only be included in MIPS64 kernels). The first, and currently only, available CPU with support for MMIDs is the MIPS I6500. This CPU supports 16 bit MMIDs, and so for now we cap our MMIDs to 16 bits wide in order to prevent the bitmap growing to absurd sizes if any future CPU does implement 32 bit MMIDs as the architecture manuals suggest is recommended. When MMIDs are in use we also make use of GINVT instruction which is available due to the global nature of MMIDs. By executing a sequence of GINVT & SYNC 0x14 instructions we can avoid the overhead of an IPI to each remote CPU in many cases. One complication is that GINVT will invalidate wired entries (in all cases apart from type 0, which targets the entire TLB). In order to avoid GINVT invalidating any wired TLB entries we set up, we make sure to create those entries using a reserved MMID (0) that we never associate with any address space. Also of note is that KVM will require further work in order to support MMIDs & GINVT, since KVM is involved in allocating IDs for guests & in configuring the MMU. That work is not part of this patch, so for now when MMIDs are in use KVM is disabled. Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: linux-mips@vger.kernel.org
2019-02-02 01:43:28 +00:00
if (cpu_has_mmid)
cpu_data[cpu].asid_cache = 0;
else if (!cpu_data[cpu].asid_cache)
cpu_data[cpu].asid_cache = asid_first_version(cpu);
mmgrab(&init_mm);
current->active_mm = &init_mm;
BUG_ON(current->mm);
enter_lazy_tlb(&init_mm, current);
/* Boot CPU's cache setup in setup_arch(). */
if (!is_boot_cpu)
cpu_cache_init();
tlb_init();
TLBMISS_HANDLER_SETUP();
}
/* Install CPU exception handler */
void set_handler(unsigned long offset, const void *addr, unsigned long size)
{
#ifdef CONFIG_CPU_MICROMIPS
memcpy((void *)(ebase + offset), ((unsigned char *)addr - 1), size);
#else
memcpy((void *)(ebase + offset), addr, size);
#endif
local_flush_icache_range(ebase + offset, ebase + offset + size);
}
format-security: move static strings to const While examining output from trial builds with -Wformat-security enabled, many strings were found that should be defined as "const", or as a char array instead of char pointer. This makes some static analysis easier, by producing fewer false positives. As these are all trivial changes, it seemed best to put them all in a single patch rather than chopping them up per maintainer. Link: http://lkml.kernel.org/r/20170405214711.GA5711@beast Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Jes Sorensen <jes@trained-monkey.org> [runner.c] Cc: Tony Lindgren <tony@atomide.com> Cc: Russell King <linux@armlinux.org.uk> Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Sean Paul <seanpaul@chromium.org> Cc: David Airlie <airlied@linux.ie> Cc: Yisen Zhuang <yisen.zhuang@huawei.com> Cc: Salil Mehta <salil.mehta@huawei.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Jiri Slaby <jslaby@suse.com> Cc: Patrice Chotard <patrice.chotard@st.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Mugunthan V N <mugunthanvnm@ti.com> Cc: Felipe Balbi <felipe.balbi@linux.intel.com> Cc: Jarod Wilson <jarod@redhat.com> Cc: Florian Westphal <fw@strlen.de> Cc: Antonio Quartulli <a@unstable.cc> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Kejian Yan <yankejian@huawei.com> Cc: Daode Huang <huangdaode@hisilicon.com> Cc: Qianqian Xie <xieqianqian@huawei.com> Cc: Philippe Reynes <tremyfr@gmail.com> Cc: Colin Ian King <colin.king@canonical.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Christian Gromm <christian.gromm@microchip.com> Cc: Andrey Shvetsov <andrey.shvetsov@k2l.de> Cc: Jason Litzinger <jlitzingerdev@gmail.com> Cc: WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-08 22:59:05 +00:00
static const char panic_null_cerr[] =
"Trying to set NULL cache error exception handler\n";
/*
* Install uncached CPU exception handler.
* This is suitable only for the cache error exception which is the only
* exception handler that is being run uncached.
*/
MIPS: Delete __cpuinit/__CPUINIT usage from MIPS code commit 3747069b25e419f6b51395f48127e9812abc3596 upstream. The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. Note that some harmless section mismatch warnings may result, since notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c) and are flagged as __cpuinit -- so if we remove the __cpuinit from the arch specific callers, we will also get section mismatch warnings. As an intermediate step, we intend to turn the linux/init.h cpuinit related content into no-ops as early as possible, since that will get rid of these warnings. In any case, they are temporary and harmless. Here, we remove all the MIPS __cpuinit from C code and __CPUINIT from asm files. MIPS is interesting in this respect, because there are also uasm users hiding behind their own renamed versions of the __cpuinit macros. [1] https://lkml.org/lkml/2013/5/20/589 [ralf@linux-mips.org: Folded in Paul's followup fix.] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/5494/ Patchwork: https://patchwork.linux-mips.org/patch/5495/ Patchwork: https://patchwork.linux-mips.org/patch/5509/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-06-18 13:38:59 +00:00
void set_uncached_handler(unsigned long offset, void *addr,
unsigned long size)
{
unsigned long uncached_ebase = CKSEG1ADDR(ebase);
if (!addr)
panic(panic_null_cerr);
memcpy((void *)(uncached_ebase + offset), addr, size);
}
static int __initdata rdhwr_noopt;
static int __init set_rdhwr_noopt(char *str)
{
rdhwr_noopt = 1;
return 1;
}
__setup("rdhwr_noopt", set_rdhwr_noopt);
void __init trap_init(void)
{
extern char except_vec3_generic;
extern char except_vec4;
extern char except_vec3_r4000;
unsigned long i, vec_size;
phys_addr_t ebase_pa;
check_wait();
if (!cpu_has_mips_r2_r6) {
ebase = CAC_BASE;
vec_size = 0x400;
} else {
if (cpu_has_veic || cpu_has_vint)
vec_size = 0x200 + VECTORSPACING*64;
else
vec_size = PAGE_SIZE;
ebase_pa = memblock_phys_alloc(vec_size, 1 << fls(vec_size));
if (!ebase_pa)
treewide: add checks for the return value of memblock_alloc*() Add check for the return value of memblock_alloc*() functions and call panic() in case of error. The panic message repeats the one used by panicing memblock allocators with adjustment of parameters to include only relevant ones. The replacement was mostly automated with semantic patches like the one below with manual massaging of format strings. @@ expression ptr, size, align; @@ ptr = memblock_alloc(size, align); + if (!ptr) + panic("%s: Failed to allocate %lu bytes align=0x%lx\n", __func__, size, align); [anders.roxell@linaro.org: use '%pa' with 'phys_addr_t' type] Link: http://lkml.kernel.org/r/20190131161046.21886-1-anders.roxell@linaro.org [rppt@linux.ibm.com: fix format strings for panics after memblock_alloc] Link: http://lkml.kernel.org/r/1548950940-15145-1-git-send-email-rppt@linux.ibm.com [rppt@linux.ibm.com: don't panic if the allocation in sparse_buffer_init fails] Link: http://lkml.kernel.org/r/20190131074018.GD28876@rapoport-lnx [akpm@linux-foundation.org: fix xtensa printk warning] Link: http://lkml.kernel.org/r/1548057848-15136-20-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Anders Roxell <anders.roxell@linaro.org> Reviewed-by: Guo Ren <ren_guo@c-sky.com> [c-sky] Acked-by: Paul Burton <paul.burton@mips.com> [MIPS] Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> [s390] Reviewed-by: Juergen Gross <jgross@suse.com> [Xen] Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Acked-by: Max Filippov <jcmvbkbc@gmail.com> [xtensa] Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Christoph Hellwig <hch@lst.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Dennis Zhou <dennis@kernel.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Mark Salter <msalter@redhat.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Petr Mladek <pmladek@suse.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Rob Herring <robh+dt@kernel.org> Cc: Rob Herring <robh@kernel.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-12 06:30:31 +00:00
panic("%s: Failed to allocate %lu bytes align=0x%x\n",
__func__, vec_size, 1 << fls(vec_size));
/*
* Try to ensure ebase resides in KSeg0 if possible.
*
* It shouldn't generally be in XKPhys on MIPS64 to avoid
* hitting a poorly defined exception base for Cache Errors.
* The allocation is likely to be in the low 512MB of physical,
* in which case we should be able to convert to KSeg0.
*
* EVA is special though as it allows segments to be rearranged
* and to become uncached during cache error handling.
*/
if (!IS_ENABLED(CONFIG_EVA) && !WARN_ON(ebase_pa >= 0x20000000))
ebase = CKSEG0ADDR(ebase_pa);
else
ebase = (unsigned long)phys_to_virt(ebase_pa);
}
if (cpu_has_mmips) {
unsigned int config3 = read_c0_config3();
if (IS_ENABLED(CONFIG_CPU_MICROMIPS))
write_c0_config3(config3 | MIPS_CONF3_ISA_OE);
else
write_c0_config3(config3 & ~MIPS_CONF3_ISA_OE);
}
if (board_ebase_setup)
board_ebase_setup();
per_cpu_trap_init(true);
memblock_set_bottom_up(false);
/*
* Copy the generic exception handlers to their final destination.
* This will be overridden later as suitable for a particular
* configuration.
*/
set_handler(0x180, &except_vec3_generic, 0x80);
/*
* Setup default vectors
*/
for (i = 0; i <= 31; i++)
set_except_vector(i, handle_reserved);
/*
* Copy the EJTAG debug exception vector handler code to it's final
* destination.
*/
if (cpu_has_ejtag && board_ejtag_handler_setup)
board_ejtag_handler_setup();
/*
* Only some CPUs have the watch exceptions.
*/
if (cpu_has_watch)
set_except_vector(EXCCODE_WATCH, handle_watch);
/*
* Initialise interrupt handlers
*/
if (cpu_has_veic || cpu_has_vint) {
int nvec = cpu_has_veic ? 64 : 8;
for (i = 0; i < nvec; i++)
set_vi_handler(i, NULL);
}
else if (cpu_has_divec)
set_handler(0x200, &except_vec4, 0x8);
/*
* Some CPUs can enable/disable for cache parity detection, but does
* it different ways.
*/
parity_protection_init();
/*
* The Data Bus Errors / Instruction Bus Errors are signaled
* by external hardware. Therefore these two exceptions
* may have board specific handlers.
*/
if (board_be_init)
board_be_init();
set_except_vector(EXCCODE_INT, using_rollback_handler() ?
rollback_handle_int : handle_int);
set_except_vector(EXCCODE_MOD, handle_tlbm);
set_except_vector(EXCCODE_TLBL, handle_tlbl);
set_except_vector(EXCCODE_TLBS, handle_tlbs);
set_except_vector(EXCCODE_ADEL, handle_adel);
set_except_vector(EXCCODE_ADES, handle_ades);
set_except_vector(EXCCODE_IBE, handle_ibe);
set_except_vector(EXCCODE_DBE, handle_dbe);
set_except_vector(EXCCODE_SYS, handle_sys);
set_except_vector(EXCCODE_BP, handle_bp);
if (rdhwr_noopt)
set_except_vector(EXCCODE_RI, handle_ri);
else {
if (cpu_has_vtag_icache)
set_except_vector(EXCCODE_RI, handle_ri_rdhwr_tlbp);
else if (current_cpu_type() == CPU_LOONGSON64)
set_except_vector(EXCCODE_RI, handle_ri_rdhwr_tlbp);
else
set_except_vector(EXCCODE_RI, handle_ri_rdhwr);
}
set_except_vector(EXCCODE_CPU, handle_cpu);
set_except_vector(EXCCODE_OV, handle_ov);
set_except_vector(EXCCODE_TR, handle_tr);
set_except_vector(EXCCODE_MSAFPE, handle_msa_fpe);
if (board_nmi_handler_setup)
board_nmi_handler_setup();
if (cpu_has_fpu && !cpu_has_nofpuex)
set_except_vector(EXCCODE_FPE, handle_fpe);
if (cpu_has_ftlbparex)
set_except_vector(MIPS_EXCCODE_TLBPAR, handle_ftlb);
MIPS: handle Loongson-specific GSExc exception Newer Loongson cores (Loongson-3A R2 and newer) use the implementation-dependent ExcCode 16 to signal Loongson-specific exceptions. The extended cause is put in the non-standard CP0.Diag1 register which is CP0 Register 22 Select 1, called GSCause in Loongson manuals. Inside is an exception code bitfield called GSExcCode, only codes 0 to 6 inclusive are documented (so far, in the Loongson 3A3000 User Manual, Volume 2). During experiments, it was found that some undocumented unprivileged instructions can trigger the also-undocumented GSExcCode 8 on Loongson 3A4000. Processor state is not corrupted, but we cannot continue without further knowledge, and Loongson is not providing that information as of this writing. So we send SIGILL on seeing this exception code to thwart easy local DoS attacks. Other exception codes are made fatal, partly because of insufficient knowledge, also partly because they are not as easily reproduced. None of them are encountered in the wild with upstream kernels and userspace so far. Some older cores (Loongson-3A1000 and Loongson-3B1500) have ExcCode 16 too, but the semantic is equivalent to GSExcCode 0. Because the respective manuals did not mention the CP0.Diag1 register or its read behavior, these cores are not covered in this patch, as MFC0 from non-existent CP0 registers is UNDEFINED according to the MIPS architecture spec. Reviewed-by: Huacai Chen <chenhc@lemote.com> Signed-off-by: WANG Xuerui <git@xen0n.name> Cc: Huacai Chen <chenhc@lemote.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2020-07-29 13:14:17 +00:00
if (cpu_has_gsexcex)
set_except_vector(LOONGSON_EXCCODE_GSEXC, handle_gsexc);
if (cpu_has_rixiex) {
set_except_vector(EXCCODE_TLBRI, tlb_do_page_fault_0);
set_except_vector(EXCCODE_TLBXI, tlb_do_page_fault_0);
}
set_except_vector(EXCCODE_MSADIS, handle_msa);
set_except_vector(EXCCODE_MDMX, handle_mdmx);
if (cpu_has_mcheck)
set_except_vector(EXCCODE_MCHECK, handle_mcheck);
if (cpu_has_mipsmt)
set_except_vector(EXCCODE_THREAD, handle_mt);
set_except_vector(EXCCODE_DSPDIS, handle_dsp);
if (board_cache_error_setup)
board_cache_error_setup();
if (cpu_has_vce)
/* Special exception: R4[04]00 uses also the divec space. */
set_handler(0x180, &except_vec3_r4000, 0x100);
else if (cpu_has_4kex)
set_handler(0x180, &except_vec3_generic, 0x80);
else
set_handler(0x080, &except_vec3_generic, 0x80);
local_flush_icache_range(ebase, ebase + vec_size);
sort_extable(__start___dbe_table, __stop___dbe_table);
cu2_notifier(default_cu2_call, 0x80000000); /* Run last */
}
static int trap_pm_notifier(struct notifier_block *self, unsigned long cmd,
void *v)
{
switch (cmd) {
case CPU_PM_ENTER_FAILED:
case CPU_PM_EXIT:
configure_status();
configure_hwrena();
configure_exception_vector();
/* Restore register with CPU number for TLB handlers */
TLBMISS_HANDLER_RESTORE();
break;
}
return NOTIFY_OK;
}
static struct notifier_block trap_pm_notifier_block = {
.notifier_call = trap_pm_notifier,
};
static int __init trap_pm_init(void)
{
return cpu_pm_register_notifier(&trap_pm_notifier_block);
}
arch_initcall(trap_pm_init);