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linux/arch/mips/kernel/traps.c
Leonid Yegoshin 078dde5e21 MIPS: traps: Set correct address limit for breakpoints and traps 
When a breakpoint or trap happens when operating in kernel mode but
on users behalf (eg syscall) it is necessary to change the address
limit to KERNEL_DS so any address checking can be bypassed and print
the correct stack trace.

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2014-03-26 23:09:13 +01:00

2188 lines
54 KiB
C
Raw Blame History

/*
* 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
* 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/bug.h>
#include <linux/compiler.h>
#include <linux/context_tracking.h>
#include <linux/kexec.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/spinlock.h>
#include <linux/kallsyms.h>
#include <linux/bootmem.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/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/mipsregs.h>
#include <asm/mipsmtregs.h>
#include <asm/module.h>
#include <asm/msa.h>
#include <asm/pgtable.h>
#include <asm/ptrace.h>
#include <asm/sections.h>
#include <asm/tlbdebug.h>
#include <asm/traps.h>
#include <asm/uaccess.h>
#include <asm/watch.h>
#include <asm/mmu_context.h>
#include <asm/types.h>
#include <asm/stacktrace.h>
#include <asm/uasm.h>
extern void check_wait(void);
extern asmlinkage void rollback_handle_int(void);
extern asmlinkage void handle_int(void);
extern u32 handle_tlbl[];
extern u32 handle_tlbs[];
extern u32 handle_tlbm[];
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_vivt(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);
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);
void (*board_be_init)(void);
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);
void(*board_cache_error_setup)(void);
static void show_raw_backtrace(unsigned long reg29)
{
unsigned long *sp = (unsigned long *)(reg29 & ~3);
unsigned long addr;
printk("Call Trace:");
#ifdef CONFIG_KALLSYMS
printk("\n");
#endif
while (!kstack_end(sp)) {
unsigned long __user *p =
(unsigned long __user *)(unsigned long)sp++;
if (__get_user(addr, p)) {
printk(" (Bad stack address)");
break;
}
if (__kernel_text_address(addr))
print_ip_sym(addr);
}
printk("\n");
}
#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)
{
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 || !__kernel_text_address(pc)) {
show_raw_backtrace(sp);
return;
}
printk("Call Trace:\n");
do {
print_ip_sym(pc);
pc = unwind_stack(task, &sp, pc, &ra);
} while (pc);
printk("\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 int field = 2 * sizeof(unsigned long);
long stackdata;
int i;
unsigned long __user *sp = (unsigned long __user *)regs->regs[29];
printk("Stack :");
i = 0;
while ((unsigned long) sp & (PAGE_SIZE - 1)) {
if (i && ((i % (64 / field)) == 0))
printk("\n ");
if (i > 39) {
printk(" ...");
break;
}
if (__get_user(stackdata, sp++)) {
printk(" (Bad stack address)");
break;
}
printk(" %0*lx", field, stackdata);
i++;
}
printk("\n");
show_backtrace(task, regs);
}
void show_stack(struct task_struct *task, unsigned long *sp)
{
struct pt_regs regs;
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;
#ifdef CONFIG_KGDB_KDB
} else if (atomic_read(&kgdb_active) != -1 &&
kdb_current_regs) {
memcpy(&regs, kdb_current_regs, sizeof(regs));
#endif /* CONFIG_KGDB_KDB */
} else {
prepare_frametrace(&regs);
}
}
show_stacktrace(task, &regs);
}
static void show_code(unsigned int __user *pc)
{
long i;
unsigned short __user *pc16 = NULL;
printk("\nCode:");
if ((unsigned long)pc & 1)
pc16 = (unsigned short __user *)((unsigned long)pc & ~1);
for(i = -3 ; i < 6 ; i++) {
unsigned int insn;
if (pc16 ? __get_user(insn, pc16 + i) : __get_user(insn, pc + i)) {
printk(" (Bad address in epc)\n");
break;
}
printk("%c%0*x%c", (i?' ':'<'), pc16 ? 4 : 8, insn, (i?' ':'>'));
}
}
static void __show_regs(const struct pt_regs *regs)
{
const int field = 2 * sizeof(unsigned long);
unsigned int cause = regs->cp0_cause;
int i;
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)
printk(" %0*lx", field, 0UL);
else if (i == 26 || i == 27)
printk(" %*s", field, "");
else
printk(" %0*lx", field, regs->regs[i]);
i++;
if ((i % 4) == 0)
printk("\n");
}
#ifdef CONFIG_CPU_HAS_SMARTMIPS
printk("Acx : %0*lx\n", field, regs->acx);
#endif
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(" %s\n", print_tainted());
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)
printk("KUo ");
if (regs->cp0_status & ST0_IEO)
printk("IEo ");
if (regs->cp0_status & ST0_KUP)
printk("KUp ");
if (regs->cp0_status & ST0_IEP)
printk("IEp ");
if (regs->cp0_status & ST0_KUC)
printk("KUc ");
if (regs->cp0_status & ST0_IEC)
printk("IEc ");
} else if (cpu_has_4kex) {
if (regs->cp0_status & ST0_KX)
printk("KX ");
if (regs->cp0_status & ST0_SX)
printk("SX ");
if (regs->cp0_status & ST0_UX)
printk("UX ");
switch (regs->cp0_status & ST0_KSU) {
case KSU_USER:
printk("USER ");
break;
case KSU_SUPERVISOR:
printk("SUPERVISOR ");
break;
case KSU_KERNEL:
printk("KERNEL ");
break;
default:
printk("BAD_MODE ");
break;
}
if (regs->cp0_status & ST0_ERL)
printk("ERL ");
if (regs->cp0_status & ST0_EXL)
printk("EXL ");
if (regs->cp0_status & ST0_IE)
printk("IE ");
}
printk("\n");
printk("Cause : %08x\n", cause);
cause = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
if (1 <= cause && cause <= 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((struct pt_regs *)regs);
}
void show_registers(struct pt_regs *regs)
{
const int field = 2 * sizeof(unsigned long);
mm_segment_t old_fs = get_fs();
__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);
}
if (!user_mode(regs))
/* Necessary for getting the correct stack content */
set_fs(KERNEL_DS);
show_stacktrace(current, regs);
show_code((unsigned int __user *) regs->cp0_epc);
printk("\n");
set_fs(old_fs);
}
static int regs_to_trapnr(struct pt_regs *regs)
{
return (regs->cp0_cause >> 2) & 0x1f;
}
static DEFINE_RAW_SPINLOCK(die_lock);
void __noreturn die(const char *str, struct pt_regs *regs)
{
static int die_counter;
int sig = SIGSEGV;
#ifdef CONFIG_MIPS_MT_SMTC
unsigned long dvpret;
#endif /* CONFIG_MIPS_MT_SMTC */
oops_enter();
if (notify_die(DIE_OOPS, str, regs, 0, regs_to_trapnr(regs),
SIGSEGV) == NOTIFY_STOP)
sig = 0;
console_verbose();
raw_spin_lock_irq(&die_lock);
#ifdef CONFIG_MIPS_MT_SMTC
dvpret = dvpe();
#endif /* CONFIG_MIPS_MT_SMTC */
bust_spinlocks(1);
#ifdef CONFIG_MIPS_MT_SMTC
mips_mt_regdump(dvpret);
#endif /* CONFIG_MIPS_MT_SMTC */
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) {
printk(KERN_EMERG "Fatal exception: panic in 5 seconds");
ssleep(5);
panic("Fatal exception");
}
if (regs && kexec_should_crash(current))
crash_kexec(regs);
do_exit(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 - 1, 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);
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, regs_to_trapnr(regs),
SIGBUS) == NOTIFY_STOP)
goto out;
die_if_kernel("Oops", regs);
force_sig(SIGBUS, current);
out:
exception_exit(prev_state);
}
/*
* ll/sc, rdhwr, sync emulation
*/
#define OPCODE 0xfc000000
#define BASE 0x03e00000
#define RT 0x001f0000
#define OFFSET 0x0000ffff
#define LL 0xc0000000
#define SC 0xe0000000
#define SPEC0 0x00000000
#define SPEC3 0x7c000000
#define RD 0x0000f800
#define FUNC 0x0000003f
#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;
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);
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;
return 0;
}
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;
if ((unsigned long)vaddr & 3)
return SIGBUS;
preempt_disable();
if (ll_bit == 0 || ll_task != current) {
regs->regs[reg] = 0;
preempt_enable();
return 0;
}
preempt_enable();
if (put_user(regs->regs[reg], vaddr))
return SIGSEGV;
regs->regs[reg] = 1;
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.
*/
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);
return simulate_ll(regs, opcode);
}
if ((opcode & OPCODE) == SC) {
perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
1, regs, 0);
return simulate_sc(regs, opcode);
}
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 0: /* CPU number */
regs->regs[rt] = smp_processor_id();
return 0;
case 1: /* SYNCI length */
regs->regs[rt] = min(current_cpu_data.dcache.linesz,
current_cpu_data.icache.linesz);
return 0;
case 2: /* Read count register */
regs->regs[rt] = read_c0_count();
return 0;
case 3: /* 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 29:
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 short 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. */
return -1;
}
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);
return 0;
}
return -1; /* Must be something else ... */
}
asmlinkage void do_ov(struct pt_regs *regs)
{
enum ctx_state prev_state;
siginfo_t info;
prev_state = exception_enter();
die_if_kernel("Integer overflow", regs);
info.si_code = FPE_INTOVF;
info.si_signo = SIGFPE;
info.si_errno = 0;
info.si_addr = (void __user *) regs->cp0_epc;
force_sig_info(SIGFPE, &info, current);
exception_exit(prev_state);
}
int process_fpemu_return(int sig, void __user *fault_addr)
{
if (sig == SIGSEGV || sig == SIGBUS) {
struct siginfo si = {0};
si.si_addr = fault_addr;
si.si_signo = sig;
if (sig == SIGSEGV) {
if (find_vma(current->mm, (unsigned long)fault_addr))
si.si_code = SEGV_ACCERR;
else
si.si_code = SEGV_MAPERR;
} else {
si.si_code = BUS_ADRERR;
}
force_sig_info(sig, &si, current);
return 1;
} else if (sig) {
force_sig(sig, current);
return 1;
} else {
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;
siginfo_t info = {0};
prev_state = exception_enter();
if (notify_die(DIE_FP, "FP exception", regs, 0, regs_to_trapnr(regs),
SIGFPE) == NOTIFY_STOP)
goto out;
die_if_kernel("FP exception in kernel code", regs);
if (fcr31 & FPU_CSR_UNI_X) {
int sig;
void __user *fault_addr = NULL;
/*
* 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.
*/
/* Ensure 'resume' not overwrite saved fp context again. */
lose_fpu(1);
/* Run the emulator */
sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
&fault_addr);
/*
* We can't allow the emulated instruction to leave any of
* the cause bit set in $fcr31.
*/
current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
/* Restore the hardware register state */
own_fpu(1); /* Using the FPU again. */
/* If something went wrong, signal */
process_fpemu_return(sig, fault_addr);
goto out;
} else if (fcr31 & FPU_CSR_INV_X)
info.si_code = FPE_FLTINV;
else if (fcr31 & FPU_CSR_DIV_X)
info.si_code = FPE_FLTDIV;
else if (fcr31 & FPU_CSR_OVF_X)
info.si_code = FPE_FLTOVF;
else if (fcr31 & FPU_CSR_UDF_X)
info.si_code = FPE_FLTUND;
else if (fcr31 & FPU_CSR_INE_X)
info.si_code = FPE_FLTRES;
else
info.si_code = __SI_FAULT;
info.si_signo = SIGFPE;
info.si_errno = 0;
info.si_addr = (void __user *) regs->cp0_epc;
force_sig_info(SIGFPE, &info, current);
out:
exception_exit(prev_state);
}
static void do_trap_or_bp(struct pt_regs *regs, unsigned int code,
const char *str)
{
siginfo_t info;
char b[40];
#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
if (kgdb_ll_trap(DIE_TRAP, str, regs, code, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
return;
#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
if (notify_die(DIE_TRAP, str, regs, code, regs_to_trapnr(regs),
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);
if (code == BRK_DIVZERO)
info.si_code = FPE_INTDIV;
else
info.si_code = FPE_INTOVF;
info.si_signo = SIGFPE;
info.si_errno = 0;
info.si_addr = (void __user *) regs->cp0_epc;
force_sig_info(SIGFPE, &info, current);
break;
case BRK_BUG:
die_if_kernel("Kernel bug detected", regs);
force_sig(SIGTRAP, current);
break;
case BRK_MEMU:
/*
* Address errors may be deliberately induced by the FPU
* emulator to retake control of the CPU after executing the
* instruction in 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, current);
break;
default:
scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
die_if_kernel(b, regs);
force_sig(SIGTRAP, current);
}
}
asmlinkage void do_bp(struct pt_regs *regs)
{
unsigned int opcode, bcode;
enum ctx_state prev_state;
unsigned long epc;
u16 instr[2];
mm_segment_t seg;
seg = get_fs();
if (!user_mode(regs))
set_fs(KERNEL_DS);
prev_state = exception_enter();
if (get_isa16_mode(regs->cp0_epc)) {
/* Calculate EPC. */
epc = exception_epc(regs);
if (cpu_has_mmips) {
if ((__get_user(instr[0], (u16 __user *)msk_isa16_mode(epc)) ||
(__get_user(instr[1], (u16 __user *)msk_isa16_mode(epc + 2)))))
goto out_sigsegv;
opcode = (instr[0] << 16) | instr[1];
} else {
/* MIPS16e mode */
if (__get_user(instr[0],
(u16 __user *)msk_isa16_mode(epc)))
goto out_sigsegv;
bcode = (instr[0] >> 6) & 0x3f;
do_trap_or_bp(regs, bcode, "Break");
goto out;
}
} else {
if (__get_user(opcode,
(unsigned int __user *) exception_epc(regs)))
goto out_sigsegv;
}
/*
* 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
*/
bcode = ((opcode >> 6) & ((1 << 20) - 1));
if (bcode >= (1 << 10))
bcode >>= 10;
/*
* notify the kprobe handlers, if instruction is likely to
* pertain to them.
*/
switch (bcode) {
case BRK_KPROBE_BP:
if (notify_die(DIE_BREAK, "debug", regs, bcode,
regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
goto out;
else
break;
case BRK_KPROBE_SSTEPBP:
if (notify_die(DIE_SSTEPBP, "single_step", regs, bcode,
regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
goto out;
else
break;
default:
break;
}
do_trap_or_bp(regs, bcode, "Break");
out:
set_fs(seg);
exception_exit(prev_state);
return;
out_sigsegv:
force_sig(SIGSEGV, current);
goto out;
}
asmlinkage void do_tr(struct pt_regs *regs)
{
u32 opcode, tcode = 0;
enum ctx_state prev_state;
u16 instr[2];
mm_segment_t seg;
unsigned long epc = msk_isa16_mode(exception_epc(regs));
seg = get_fs();
if (!user_mode(regs))
set_fs(get_ds());
prev_state = exception_enter();
if (get_isa16_mode(regs->cp0_epc)) {
if (__get_user(instr[0], (u16 __user *)(epc + 0)) ||
__get_user(instr[1], (u16 __user *)(epc + 2)))
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_user(opcode, (u32 __user *)epc))
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, "Trap");
out:
set_fs(seg);
exception_exit(prev_state);
return;
out_sigsegv:
force_sig(SIGSEGV, current);
goto out;
}
asmlinkage void do_ri(struct pt_regs *regs)
{
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;
unsigned int opcode = 0;
int status = -1;
prev_state = exception_enter();
if (notify_die(DIE_RI, "RI Fault", regs, 0, regs_to_trapnr(regs),
SIGILL) == NOTIFY_STOP)
goto out;
die_if_kernel("Reserved instruction in kernel code", regs);
if (unlikely(compute_return_epc(regs) < 0))
goto out;
if (get_isa16_mode(regs->cp0_epc)) {
unsigned short mmop[2] = { 0 };
if (unlikely(get_user(mmop[0], epc) < 0))
status = SIGSEGV;
if (unlikely(get_user(mmop[1], epc) < 0))
status = SIGSEGV;
opcode = (mmop[0] << 16) | mmop[1];
if (status < 0)
status = simulate_rdhwr_mm(regs, opcode);
} else {
if (unlikely(get_user(opcode, epc) < 0))
status = SIGSEGV;
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);
}
if (status < 0)
status = SIGILL;
if (unlikely(status > 0)) {
regs->cp0_epc = old_epc; /* Undo skip-over. */
regs->regs[31] = old31;
force_sig(status, current);
}
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 (cpus_intersects(current->cpus_allowed, mt_fpu_cpumask)) {
cpumask_t tmask;
current->thread.user_cpus_allowed
= current->cpus_allowed;
cpus_and(tmask, current->cpus_allowed,
mt_fpu_cpumask);
set_cpus_allowed_ptr(current, &tmask);
set_thread_flag(TIF_FPUBOUND);
}
}
#endif /* CONFIG_MIPS_MT_FPAFF */
}
/*
* 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, current);
return NOTIFY_OK;
}
static int enable_restore_fp_context(int msa)
{
int err, was_fpu_owner;
if (!used_math()) {
/* First time FP context user. */
err = init_fpu();
if (msa && !err)
enable_msa();
if (!err)
set_used_math();
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.
*/
was_fpu_owner = is_fpu_owner();
err = own_fpu(0);
if (err)
return err;
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.
*/
if (!test_and_set_thread_flag(TIF_MSA_CTX_LIVE) && was_fpu_owner)
return 0;
/* We need to restore the vector context. */
restore_msa(current);
return 0;
}
asmlinkage void do_cpu(struct pt_regs *regs)
{
enum ctx_state prev_state;
unsigned int __user *epc;
unsigned long old_epc, old31;
unsigned int opcode;
unsigned int cpid;
int status, err;
unsigned long __maybe_unused flags;
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:
epc = (unsigned int __user *)exception_epc(regs);
old_epc = regs->cp0_epc;
old31 = regs->regs[31];
opcode = 0;
status = -1;
if (unlikely(compute_return_epc(regs) < 0))
goto out;
if (get_isa16_mode(regs->cp0_epc)) {
unsigned short mmop[2] = { 0 };
if (unlikely(get_user(mmop[0], epc) < 0))
status = SIGSEGV;
if (unlikely(get_user(mmop[1], epc) < 0))
status = SIGSEGV;
opcode = (mmop[0] << 16) | mmop[1];
if (status < 0)
status = simulate_rdhwr_mm(regs, opcode);
} else {
if (unlikely(get_user(opcode, epc) < 0))
status = SIGSEGV;
if (!cpu_has_llsc && status < 0)
status = simulate_llsc(regs, opcode);
if (status < 0)
status = simulate_rdhwr_normal(regs, opcode);
}
if (status < 0)
status = SIGILL;
if (unlikely(status > 0)) {
regs->cp0_epc = old_epc; /* Undo skip-over. */
regs->regs[31] = old31;
force_sig(status, current);
}
goto out;
case 3:
/*
* Old (MIPS I and MIPS II) processors will set this code
* for COP1X opcode instructions that replaced the original
* COP3 space. We don't limit COP1 space instructions in
* the emulator according to the CPU ISA, so we want to
* treat COP1X instructions consistently regardless of which
* code the CPU chose. Therefore we redirect this trap to
* the FP emulator too.
*
* Then some newer FPU-less processors use this code
* erroneously too, so they are covered by this choice
* as well.
*/
if (raw_cpu_has_fpu)
break;
/* Fall through. */
case 1:
err = enable_restore_fp_context(0);
if (!raw_cpu_has_fpu || err) {
int sig;
void __user *fault_addr = NULL;
sig = fpu_emulator_cop1Handler(regs,
&current->thread.fpu,
0, &fault_addr);
if (!process_fpemu_return(sig, fault_addr) && !err)
mt_ase_fp_affinity();
}
goto out;
case 2:
raw_notifier_call_chain(&cu2_chain, CU2_EXCEPTION, regs);
goto out;
}
force_sig(SIGILL, current);
out:
exception_exit(prev_state);
}
asmlinkage void do_msa_fpe(struct pt_regs *regs)
{
enum ctx_state prev_state;
prev_state = exception_enter();
die_if_kernel("do_msa_fpe invoked from kernel context!", regs);
force_sig(SIGFPE, current);
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, current);
goto out;
}
die_if_kernel("do_msa invoked from kernel context!", regs);
err = enable_restore_fp_context(1);
if (err)
force_sig(SIGILL, current);
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, current);
exception_exit(prev_state);
}
/*
* Called with interrupts disabled.
*/
asmlinkage void do_watch(struct pt_regs *regs)
{
enum ctx_state prev_state;
u32 cause;
prev_state = exception_enter();
/*
* Clear WP (bit 22) bit of cause register so we don't loop
* forever.
*/
cause = read_c0_cause();
cause &= ~(1 << 22);
write_c0_cause(cause);
/*
* 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(SIGTRAP, current);
} else {
mips_clear_watch_registers();
local_irq_enable();
}
exception_exit(prev_state);
}
asmlinkage void do_mcheck(struct pt_regs *regs)
{
const int field = 2 * sizeof(unsigned long);
int multi_match = regs->cp0_status & ST0_TS;
enum ctx_state prev_state;
prev_state = exception_enter();
show_regs(regs);
if (multi_match) {
printk("Index : %0x\n", read_c0_index());
printk("Pagemask: %0x\n", read_c0_pagemask());
printk("EntryHi : %0*lx\n", field, read_c0_entryhi());
printk("EntryLo0: %0*lx\n", field, read_c0_entrylo0());
printk("EntryLo1: %0*lx\n", field, read_c0_entrylo1());
printk("\n");
dump_tlb_all();
}
show_code((unsigned int __user *) regs->cp0_epc);
/*
* 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, current);
}
asmlinkage void do_dsp(struct pt_regs *regs)
{
if (cpu_has_dsp)
panic("Unexpected DSP exception");
force_sig(SIGILL, current);
}
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 void parity_protection_init(void)
{
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:
{
#define ERRCTL_PE 0x80000000
#define ERRCTL_L2P 0x00800000
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_LOONGSON1:
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 &&
((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 &&
((current_cpu_data.processor_id && 0xff0000) == PRID_COMP_MIPS)) {
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();
}
/*
* 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];
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);
}
#define VECTORSPACING 0x100 /* for EI/VI mode */
unsigned long ebase;
unsigned long exception_handlers[32];
unsigned long vi_handlers[64];
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;
}
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 char except_vec_vi, except_vec_vi_lui;
extern char except_vec_vi_ori, except_vec_vi_end;
extern char rollback_except_vec_vi;
char *vec_start = using_rollback_handler() ?
&rollback_except_vec_vi : &except_vec_vi;
#ifdef CONFIG_MIPS_MT_SMTC
/*
* We need to provide the SMTC vectored interrupt handler
* not only with the address of the handler, but with the
* Status.IM bit to be masked before going there.
*/
extern char except_vec_vi_mori;
#if defined(CONFIG_CPU_MICROMIPS) || defined(CONFIG_CPU_BIG_ENDIAN)
const int mori_offset = &except_vec_vi_mori - vec_start + 2;
#else
const int mori_offset = &except_vec_vi_mori - vec_start;
#endif
#endif /* CONFIG_MIPS_MT_SMTC */
#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
#ifdef CONFIG_MIPS_MT_SMTC
BUG_ON(n > 7); /* Vector index %d exceeds SMTC maximum. */
h = (u16 *)(b + mori_offset);
*h = (0x100 << n);
#endif /* CONFIG_MIPS_MT_SMTC */
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);
static int noulri;
static int __init ulri_disable(char *s)
{
pr_info("Disabling ulri\n");
noulri = 1;
return 1;
}
__setup("noulri", ulri_disable);
void per_cpu_trap_init(bool is_boot_cpu)
{
unsigned int cpu = smp_processor_id();
unsigned int status_set = ST0_CU0;
unsigned int hwrena = cpu_hwrena_impl_bits;
#ifdef CONFIG_MIPS_MT_SMTC
int secondaryTC = 0;
int bootTC = (cpu == 0);
/*
* Only do per_cpu_trap_init() for first TC of Each VPE.
* Note that this hack assumes that the SMTC init code
* assigns TCs consecutively and in ascending order.
*/
if (((read_c0_tcbind() & TCBIND_CURTC) != 0) &&
((read_c0_tcbind() & TCBIND_CURVPE) == cpu_data[cpu - 1].vpe_id))
secondaryTC = 1;
#endif /* CONFIG_MIPS_MT_SMTC */
/*
* 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.
*/
#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);
if (cpu_has_mips_r2)
hwrena |= 0x0000000f;
if (!noulri && cpu_has_userlocal)
hwrena |= (1 << 29);
if (hwrena)
write_c0_hwrena(hwrena);
#ifdef CONFIG_MIPS_MT_SMTC
if (!secondaryTC) {
#endif /* CONFIG_MIPS_MT_SMTC */
if (cpu_has_veic || cpu_has_vint) {
unsigned long sr = set_c0_status(ST0_BEV);
write_c0_ebase(ebase);
write_c0_status(sr);
/* 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);
}
/*
* 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
*/
if (cpu_has_mips_r2) {
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;
if (cp0_perfcount_irq == cp0_compare_irq)
cp0_perfcount_irq = -1;
} else {
cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
cp0_compare_irq_shift = CP0_LEGACY_PERFCNT_IRQ;
cp0_perfcount_irq = -1;
}
#ifdef CONFIG_MIPS_MT_SMTC
}
#endif /* CONFIG_MIPS_MT_SMTC */
if (!cpu_data[cpu].asid_cache)
cpu_data[cpu].asid_cache = ASID_FIRST_VERSION;
atomic_inc(&init_mm.mm_count);
current->active_mm = &init_mm;
BUG_ON(current->mm);
enter_lazy_tlb(&init_mm, current);
#ifdef CONFIG_MIPS_MT_SMTC
if (bootTC) {
#endif /* CONFIG_MIPS_MT_SMTC */
/* Boot CPU's cache setup in setup_arch(). */
if (!is_boot_cpu)
cpu_cache_init();
tlb_init();
#ifdef CONFIG_MIPS_MT_SMTC
} else if (!secondaryTC) {
/*
* First TC in non-boot VPE must do subset of tlb_init()
* for MMU countrol registers.
*/
write_c0_pagemask(PM_DEFAULT_MASK);
write_c0_wired(0);
}
#endif /* CONFIG_MIPS_MT_SMTC */
TLBMISS_HANDLER_SETUP();
}
/* Install CPU exception handler */
void set_handler(unsigned long offset, 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);
}
static char panic_null_cerr[] =
"Trying to set NULL cache error exception handler";
/*
* 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.
*/
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;
check_wait();
#if defined(CONFIG_KGDB)
if (kgdb_early_setup)
return; /* Already done */
#endif
if (cpu_has_veic || cpu_has_vint) {
unsigned long size = 0x200 + VECTORSPACING*64;
ebase = (unsigned long)
__alloc_bootmem(size, 1 << fls(size), 0);
} else {
#ifdef CONFIG_KVM_GUEST
#define KVM_GUEST_KSEG0 0x40000000
ebase = KVM_GUEST_KSEG0;
#else
ebase = CKSEG0;
#endif
if (cpu_has_mips_r2)
ebase += (read_c0_ebase() & 0x3ffff000);
}
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);
/*
* Copy the generic exception handlers to their final destination.
* This will be overriden 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(23, 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(0, using_rollback_handler() ? rollback_handle_int
: handle_int);
set_except_vector(1, handle_tlbm);
set_except_vector(2, handle_tlbl);
set_except_vector(3, handle_tlbs);
set_except_vector(4, handle_adel);
set_except_vector(5, handle_ades);
set_except_vector(6, handle_ibe);
set_except_vector(7, handle_dbe);
set_except_vector(8, handle_sys);
set_except_vector(9, handle_bp);
set_except_vector(10, rdhwr_noopt ? handle_ri :
(cpu_has_vtag_icache ?
handle_ri_rdhwr_vivt : handle_ri_rdhwr));
set_except_vector(11, handle_cpu);
set_except_vector(12, handle_ov);
set_except_vector(13, handle_tr);
set_except_vector(14, handle_msa_fpe);
if (current_cpu_type() == CPU_R6000 ||
current_cpu_type() == CPU_R6000A) {
/*
* The R6000 is the only R-series CPU that features a machine
* check exception (similar to the R4000 cache error) and
* unaligned ldc1/sdc1 exception. The handlers have not been
* written yet. Well, anyway there is no R6000 machine on the
* current list of targets for Linux/MIPS.
* (Duh, crap, there is someone with a triple R6k machine)
*/
//set_except_vector(14, handle_mc);
//set_except_vector(15, handle_ndc);
}
if (board_nmi_handler_setup)
board_nmi_handler_setup();
if (cpu_has_fpu && !cpu_has_nofpuex)
set_except_vector(15, handle_fpe);
set_except_vector(16, handle_ftlb);
set_except_vector(21, handle_msa);
set_except_vector(22, handle_mdmx);
if (cpu_has_mcheck)
set_except_vector(24, handle_mcheck);
if (cpu_has_mipsmt)
set_except_vector(25, handle_mt);
set_except_vector(26, 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 + 0x400);
sort_extable(__start___dbe_table, __stop___dbe_table);
cu2_notifier(default_cu2_call, 0x80000000); /* Run last */
}
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