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linux/arch/mips/kernel/traps.c
Pavel Emelianov bcdcd8e725 Report that kernel is tainted if there was an OOPS 
If the kernel OOPSed or BUGed then it probably should be considered as
tainted.  Thus, all subsequent OOPSes and SysRq dumps will report the
tainted kernel.  This saves a lot of time explaining oddities in the
calltraces.

Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Added parisc patch from Matthew Wilson  -Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:02 -07:00

1586 lines
38 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) 2000, 01 MIPS Technologies, Inc.
* Copyright (C) 2002, 2003, 2004, 2005 Maciej W. Rozycki
*/
#include <linux/bug.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/module.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 <asm/bootinfo.h>
#include <asm/branch.h>
#include <asm/break.h>
#include <asm/cpu.h>
#include <asm/dsp.h>
#include <asm/fpu.h>
#include <asm/mipsregs.h>
#include <asm/mipsmtregs.h>
#include <asm/module.h>
#include <asm/pgtable.h>
#include <asm/ptrace.h>
#include <asm/sections.h>
#include <asm/system.h>
#include <asm/tlbdebug.h>
#include <asm/traps.h>
#include <asm/uaccess.h>
#include <asm/mmu_context.h>
#include <asm/types.h>
#include <asm/stacktrace.h>
extern asmlinkage void handle_int(void);
extern asmlinkage void handle_tlbm(void);
extern asmlinkage void handle_tlbl(void);
extern asmlinkage void handle_tlbs(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_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_fpe(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 int fpu_emulator_cop1Handler(struct pt_regs *xcp,
struct mips_fpu_struct *ctx, int has_fpu);
void (*board_watchpoint_handler)(struct pt_regs *regs);
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);
static void show_raw_backtrace(unsigned long reg29)
{
unsigned long *sp = (unsigned long *)reg29;
unsigned long addr;
printk("Call Trace:");
#ifdef CONFIG_KALLSYMS
printk("\n");
#endif
while (!kstack_end(sp)) {
addr = *sp++;
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, struct pt_regs *regs)
{
unsigned long sp = regs->regs[29];
unsigned long ra = regs->regs[31];
unsigned long pc = regs->cp0_epc;
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, 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;
} else {
prepare_frametrace(&regs);
}
}
show_stacktrace(task, &regs);
}
/*
* The architecture-independent dump_stack generator
*/
void dump_stack(void)
{
struct pt_regs regs;
prepare_frametrace(&regs);
show_backtrace(current, &regs);
}
EXPORT_SYMBOL(dump_stack);
static void show_code(unsigned int __user *pc)
{
long i;
printk("\nCode:");
for(i = -3 ; i < 6 ; i++) {
unsigned int insn;
if (__get_user(insn, pc + i)) {
printk(" (Bad address in epc)\n");
break;
}
printk("%c%08x%c", (i?' ':'<'), insn, (i?' ':'>'));
}
}
void show_regs(struct pt_regs *regs)
{
const int field = 2 * sizeof(unsigned long);
unsigned int cause = regs->cp0_cause;
int i;
printk("Cpu %d\n", smp_processor_id());
/*
* 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 ", field, regs->cp0_epc);
print_symbol("%s ", regs->cp0_epc);
printk(" %s\n", print_tainted());
printk("ra : %0*lx ", field, regs->regs[31]);
print_symbol("%s\n", regs->regs[31]);
printk("Status: %08x ", (uint32_t) regs->cp0_status);
if (current_cpu_data.isa_level == MIPS_CPU_ISA_I) {
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 (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\n", read_c0_prid());
}
void show_registers(struct pt_regs *regs)
{
show_regs(regs);
print_modules();
printk("Process %s (pid: %d, threadinfo=%p, task=%p)\n",
current->comm, current->pid, current_thread_info(), current);
show_stacktrace(current, regs);
show_code((unsigned int __user *) regs->cp0_epc);
printk("\n");
}
static DEFINE_SPINLOCK(die_lock);
void __noreturn die(const char * str, struct pt_regs * regs)
{
static int die_counter;
#ifdef CONFIG_MIPS_MT_SMTC
unsigned long dvpret = dvpe();
#endif /* CONFIG_MIPS_MT_SMTC */
console_verbose();
spin_lock_irq(&die_lock);
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);
spin_unlock_irq(&die_lock);
if (in_interrupt())
panic("Fatal exception in interrupt");
if (panic_on_oops) {
printk(KERN_EMERG "Fatal exception: panic in 5 seconds\n");
ssleep(5);
panic("Fatal exception");
}
do_exit(SIGSEGV);
}
extern const struct exception_table_entry __start___dbe_table[];
extern const 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;
/* 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:
return;
case MIPS_BE_FIXUP:
if (fixup) {
regs->cp0_epc = fixup->nextinsn;
return;
}
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]);
die_if_kernel("Oops", regs);
force_sig(SIGBUS, current);
}
/*
* ll/sc emulation
*/
#define OPCODE 0xfc000000
#define BASE 0x03e00000
#define RT 0x001f0000
#define OFFSET 0x0000ffff
#define LL 0xc0000000
#define SC 0xe0000000
#define SPEC3 0x7c000000
#define RD 0x0000f800
#define FUNC 0x0000003f
#define RDHWR 0x0000003b
/*
* The ll_bit is cleared by r*_switch.S
*/
unsigned long ll_bit;
static struct task_struct *ll_task = NULL;
static inline void simulate_ll(struct pt_regs *regs, unsigned int opcode)
{
unsigned long value, __user *vaddr;
long offset;
int signal = 0;
/*
* 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) {
signal = SIGBUS;
goto sig;
}
if (get_user(value, vaddr)) {
signal = SIGSEGV;
goto sig;
}
preempt_disable();
if (ll_task == NULL || ll_task == current) {
ll_bit = 1;
} else {
ll_bit = 0;
}
ll_task = current;
preempt_enable();
compute_return_epc(regs);
regs->regs[(opcode & RT) >> 16] = value;
return;
sig:
force_sig(signal, current);
}
static inline void simulate_sc(struct pt_regs *regs, unsigned int opcode)
{
unsigned long __user *vaddr;
unsigned long reg;
long offset;
int signal = 0;
/*
* 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) {
signal = SIGBUS;
goto sig;
}
preempt_disable();
if (ll_bit == 0 || ll_task != current) {
compute_return_epc(regs);
regs->regs[reg] = 0;
preempt_enable();
return;
}
preempt_enable();
if (put_user(regs->regs[reg], vaddr)) {
signal = SIGSEGV;
goto sig;
}
compute_return_epc(regs);
regs->regs[reg] = 1;
return;
sig:
force_sig(signal, current);
}
/*
* 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 inline int simulate_llsc(struct pt_regs *regs)
{
unsigned int opcode;
if (get_user(opcode, (unsigned int __user *) exception_epc(regs)))
goto out_sigsegv;
if ((opcode & OPCODE) == LL) {
simulate_ll(regs, opcode);
return 0;
}
if ((opcode & OPCODE) == SC) {
simulate_sc(regs, opcode);
return 0;
}
return -EFAULT; /* Strange things going on ... */
out_sigsegv:
force_sig(SIGSEGV, current);
return -EFAULT;
}
/*
* Simulate trapping 'rdhwr' instructions to provide user accessible
* registers not implemented in hardware. The only current use of this
* is the thread area pointer.
*/
static inline int simulate_rdhwr(struct pt_regs *regs)
{
struct thread_info *ti = task_thread_info(current);
unsigned int opcode;
if (get_user(opcode, (unsigned int __user *) exception_epc(regs)))
goto out_sigsegv;
if (unlikely(compute_return_epc(regs)))
return -EFAULT;
if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
int rd = (opcode & RD) >> 11;
int rt = (opcode & RT) >> 16;
switch (rd) {
case 29:
regs->regs[rt] = ti->tp_value;
return 0;
default:
return -EFAULT;
}
}
/* Not ours. */
return -EFAULT;
out_sigsegv:
force_sig(SIGSEGV, current);
return -EFAULT;
}
asmlinkage void do_ov(struct pt_regs *regs)
{
siginfo_t info;
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);
}
/*
* XXX Delayed fp exceptions when doing a lazy ctx switch XXX
*/
asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
{
die_if_kernel("FP exception in kernel code", regs);
if (fcr31 & FPU_CSR_UNI_X) {
int sig;
/*
* 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);
/*
* 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 */
if (sig)
force_sig(sig, current);
return;
}
force_sig(SIGFPE, current);
}
asmlinkage void do_bp(struct pt_regs *regs)
{
unsigned int opcode, bcode;
siginfo_t info;
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;
/*
* (A short test says that IRIX 5.3 sends SIGTRAP for all break
* insns, even for break codes that indicate arithmetic failures.
* Weird ...)
* But should we continue the brokenness??? --macro
*/
switch (bcode) {
case BRK_OVERFLOW << 10:
case BRK_DIVZERO << 10:
die_if_kernel("Break instruction in kernel code", regs);
if (bcode == (BRK_DIVZERO << 10))
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("Kernel bug detected", regs);
break;
default:
die_if_kernel("Break instruction in kernel code", regs);
force_sig(SIGTRAP, current);
}
return;
out_sigsegv:
force_sig(SIGSEGV, current);
}
asmlinkage void do_tr(struct pt_regs *regs)
{
unsigned int opcode, tcode = 0;
siginfo_t info;
if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
goto out_sigsegv;
/* Immediate versions don't provide a code. */
if (!(opcode & OPCODE))
tcode = ((opcode >> 6) & ((1 << 10) - 1));
/*
* (A short test says that IRIX 5.3 sends SIGTRAP for all trap
* insns, even for trap codes that indicate arithmetic failures.
* Weird ...)
* But should we continue the brokenness??? --macro
*/
switch (tcode) {
case BRK_OVERFLOW:
case BRK_DIVZERO:
die_if_kernel("Trap instruction in kernel code", regs);
if (tcode == 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("Kernel bug detected", regs);
break;
default:
die_if_kernel("Trap instruction in kernel code", regs);
force_sig(SIGTRAP, current);
}
return;
out_sigsegv:
force_sig(SIGSEGV, current);
}
asmlinkage void do_ri(struct pt_regs *regs)
{
die_if_kernel("Reserved instruction in kernel code", regs);
if (!cpu_has_llsc)
if (!simulate_llsc(regs))
return;
if (!simulate_rdhwr(regs))
return;
force_sig(SIGILL, current);
}
/*
* 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;
cpus_and(tmask, current->thread.user_cpus_allowed,
mt_fpu_cpumask);
set_cpus_allowed(current, tmask);
current->thread.mflags |= MF_FPUBOUND;
}
}
#endif /* CONFIG_MIPS_MT_FPAFF */
}
asmlinkage void do_cpu(struct pt_regs *regs)
{
unsigned int cpid;
die_if_kernel("do_cpu invoked from kernel context!", regs);
cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
switch (cpid) {
case 0:
if (!cpu_has_llsc)
if (!simulate_llsc(regs))
return;
if (!simulate_rdhwr(regs))
return;
break;
case 1:
if (used_math()) /* Using the FPU again. */
own_fpu(1);
else { /* First time FPU user. */
init_fpu();
set_used_math();
}
if (!raw_cpu_has_fpu) {
int sig;
sig = fpu_emulator_cop1Handler(regs,
&current->thread.fpu, 0);
if (sig)
force_sig(sig, current);
else
mt_ase_fp_affinity();
}
return;
case 2:
case 3:
break;
}
force_sig(SIGILL, current);
}
asmlinkage void do_mdmx(struct pt_regs *regs)
{
force_sig(SIGILL, current);
}
asmlinkage void do_watch(struct pt_regs *regs)
{
if (board_watchpoint_handler) {
(*board_watchpoint_handler)(regs);
return;
}
/*
* We use the watch exception where available to detect stack
* overflows.
*/
dump_tlb_all();
show_regs(regs);
panic("Caught WATCH exception - probably caused by stack overflow.");
}
asmlinkage void do_mcheck(struct pt_regs *regs)
{
const int field = 2 * sizeof(unsigned long);
int multi_match = regs->cp0_status & ST0_TS;
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 Schedulier 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\n");
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);
}
/*
* 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_data.cputype) {
case CPU_24K:
case CPU_34K:
case CPU_5KC:
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");
printk("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!");
}
/*
* 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;
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;
regs->cp0_epc = depc;
__compute_return_epc(regs);
depc = regs->cp0_epc;
regs->cp0_epc = old_epc;
} 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.
*/
void nmi_exception_handler(struct pt_regs *regs)
{
#ifdef CONFIG_MIPS_MT_SMTC
unsigned long dvpret = dvpe();
bust_spinlocks(1);
printk("NMI taken!!!!\n");
mips_mt_regdump(dvpret);
#else
bust_spinlocks(1);
printk("NMI taken!!!!\n");
#endif /* CONFIG_MIPS_MT_SMTC */
die("NMI", regs);
while(1) ;
}
#define VECTORSPACING 0x100 /* for EI/VI mode */
unsigned long ebase;
unsigned long exception_handlers[32];
unsigned long vi_handlers[64];
/*
* As a side effect of the way this is implemented we're limited
* to interrupt handlers in the address range from
* KSEG0 <= x < KSEG0 + 256mb on the Nevada. Oh well ...
*/
void *set_except_vector(int n, void *addr)
{
unsigned long handler = (unsigned long) addr;
unsigned long old_handler = exception_handlers[n];
exception_handlers[n] = handler;
if (n == 0 && cpu_has_divec) {
*(volatile u32 *)(ebase + 0x200) = 0x08000000 |
(0x03ffffff & (handler >> 2));
flush_icache_range(ebase + 0x200, ebase + 0x204);
}
return (void *)old_handler;
}
#ifdef CONFIG_CPU_MIPSR2_SRS
/*
* MIPSR2 shadow register set allocation
* FIXME: SMP...
*/
static struct shadow_registers {
/*
* Number of shadow register sets supported
*/
unsigned long sr_supported;
/*
* Bitmap of allocated shadow registers
*/
unsigned long sr_allocated;
} shadow_registers;
static void mips_srs_init(void)
{
shadow_registers.sr_supported = ((read_c0_srsctl() >> 26) & 0x0f) + 1;
printk(KERN_INFO "%ld MIPSR2 register sets available\n",
shadow_registers.sr_supported);
shadow_registers.sr_allocated = 1; /* Set 0 used by kernel */
}
int mips_srs_max(void)
{
return shadow_registers.sr_supported;
}
int mips_srs_alloc(void)
{
struct shadow_registers *sr = &shadow_registers;
int set;
again:
set = find_first_zero_bit(&sr->sr_allocated, sr->sr_supported);
if (set >= sr->sr_supported)
return -1;
if (test_and_set_bit(set, &sr->sr_allocated))
goto again;
return set;
}
void mips_srs_free(int set)
{
struct shadow_registers *sr = &shadow_registers;
clear_bit(set, &sr->sr_allocated);
}
static asmlinkage 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];
u32 *w;
unsigned char *b;
if (!cpu_has_veic && !cpu_has_vint)
BUG();
if (addr == NULL) {
handler = (unsigned long) do_default_vi;
srs = 0;
} else
handler = (unsigned long) addr;
vi_handlers[n] = (unsigned long) addr;
b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);
if (srs >= mips_srs_max())
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 (mips_srs_max() > 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 a standard interrupt exit
*/
extern char except_vec_vi, except_vec_vi_lui;
extern char except_vec_vi_ori, except_vec_vi_end;
#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;
const int mori_offset = &except_vec_vi_mori - &except_vec_vi;
#endif /* CONFIG_MIPS_MT_SMTC */
const int handler_len = &except_vec_vi_end - &except_vec_vi;
const int lui_offset = &except_vec_vi_lui - &except_vec_vi;
const int ori_offset = &except_vec_vi_ori - &except_vec_vi;
if (handler_len > VECTORSPACING) {
/*
* Sigh... panicing won't help as the console
* is probably not configured :(
*/
panic ("VECTORSPACING too small");
}
memcpy (b, &except_vec_vi, handler_len);
#ifdef CONFIG_MIPS_MT_SMTC
BUG_ON(n > 7); /* Vector index %d exceeds SMTC maximum. */
w = (u32 *)(b + mori_offset);
*w = (*w & 0xffff0000) | (0x100 << n);
#endif /* CONFIG_MIPS_MT_SMTC */
w = (u32 *)(b + lui_offset);
*w = (*w & 0xffff0000) | (((u32)handler >> 16) & 0xffff);
w = (u32 *)(b + ori_offset);
*w = (*w & 0xffff0000) | ((u32)handler & 0xffff);
flush_icache_range((unsigned long)b, (unsigned long)(b+handler_len));
}
else {
/*
* In other cases jump directly to the interrupt handler
*
* It is the handlers responsibility to save registers if required
* (eg hi/lo) and return from the exception using "eret"
*/
w = (u32 *)b;
*w++ = 0x08000000 | (((u32)handler >> 2) & 0x03fffff); /* j handler */
*w = 0;
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);
}
#else
static inline void mips_srs_init(void)
{
}
#endif /* CONFIG_CPU_MIPSR2_SRS */
/*
* This is used by native signal handling
*/
asmlinkage int (*save_fp_context)(struct sigcontext __user *sc);
asmlinkage int (*restore_fp_context)(struct sigcontext __user *sc);
extern asmlinkage int _save_fp_context(struct sigcontext __user *sc);
extern asmlinkage int _restore_fp_context(struct sigcontext __user *sc);
extern asmlinkage int fpu_emulator_save_context(struct sigcontext __user *sc);
extern asmlinkage int fpu_emulator_restore_context(struct sigcontext __user *sc);
#ifdef CONFIG_SMP
static int smp_save_fp_context(struct sigcontext __user *sc)
{
return raw_cpu_has_fpu
? _save_fp_context(sc)
: fpu_emulator_save_context(sc);
}
static int smp_restore_fp_context(struct sigcontext __user *sc)
{
return raw_cpu_has_fpu
? _restore_fp_context(sc)
: fpu_emulator_restore_context(sc);
}
#endif
static inline void signal_init(void)
{
#ifdef CONFIG_SMP
/* For now just do the cpu_has_fpu check when the functions are invoked */
save_fp_context = smp_save_fp_context;
restore_fp_context = smp_restore_fp_context;
#else
if (cpu_has_fpu) {
save_fp_context = _save_fp_context;
restore_fp_context = _restore_fp_context;
} else {
save_fp_context = fpu_emulator_save_context;
restore_fp_context = fpu_emulator_restore_context;
}
#endif
}
#ifdef CONFIG_MIPS32_COMPAT
/*
* This is used by 32-bit signal stuff on the 64-bit kernel
*/
asmlinkage int (*save_fp_context32)(struct sigcontext32 __user *sc);
asmlinkage int (*restore_fp_context32)(struct sigcontext32 __user *sc);
extern asmlinkage int _save_fp_context32(struct sigcontext32 __user *sc);
extern asmlinkage int _restore_fp_context32(struct sigcontext32 __user *sc);
extern asmlinkage int fpu_emulator_save_context32(struct sigcontext32 __user *sc);
extern asmlinkage int fpu_emulator_restore_context32(struct sigcontext32 __user *sc);
static inline void signal32_init(void)
{
if (cpu_has_fpu) {
save_fp_context32 = _save_fp_context32;
restore_fp_context32 = _restore_fp_context32;
} else {
save_fp_context32 = fpu_emulator_save_context32;
restore_fp_context32 = fpu_emulator_restore_context32;
}
}
#endif
extern void cpu_cache_init(void);
extern void tlb_init(void);
extern void flush_tlb_handlers(void);
void __init per_cpu_trap_init(void)
{
unsigned int cpu = smp_processor_id();
unsigned int status_set = ST0_CU0;
#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;
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_dsp)
set_c0_status(ST0_MX);
#ifdef CONFIG_CPU_MIPSR2
if (cpu_has_mips_r2) {
unsigned int enable = 0x0000000f;
if (cpu_has_userlocal)
enable |= (1 << 29);
write_c0_hwrena(enable);
}
#endif
#ifdef CONFIG_MIPS_MT_SMTC
if (!secondaryTC) {
#endif /* CONFIG_MIPS_MT_SMTC */
if (cpu_has_veic || cpu_has_vint) {
write_c0_ebase (ebase);
/* 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 = (read_c0_intctl () >> 29) & 7;
cp0_perfcount_irq = (read_c0_intctl () >> 26) & 7;
if (cp0_perfcount_irq == cp0_compare_irq)
cp0_perfcount_irq = -1;
} else {
cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
cp0_perfcount_irq = -1;
}
#ifdef CONFIG_MIPS_MT_SMTC
}
#endif /* CONFIG_MIPS_MT_SMTC */
cpu_data[cpu].asid_cache = ASID_FIRST_VERSION;
TLBMISS_HANDLER_SETUP();
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 */
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 */
}
/* Install CPU exception handler */
void __init set_handler (unsigned long offset, void *addr, unsigned long size)
{
memcpy((void *)(ebase + offset), addr, size);
flush_icache_range(ebase + offset, ebase + offset + size);
}
/* Install uncached CPU exception handler */
void __init set_uncached_handler (unsigned long offset, void *addr, unsigned long size)
{
#ifdef CONFIG_32BIT
unsigned long uncached_ebase = KSEG1ADDR(ebase);
#endif
#ifdef CONFIG_64BIT
unsigned long uncached_ebase = TO_UNCAC(ebase);
#endif
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, except_vec3_r4000;
extern char except_vec4;
unsigned long i;
if (cpu_has_veic || cpu_has_vint)
ebase = (unsigned long) alloc_bootmem_low_pages (0x200 + VECTORSPACING*64);
else
ebase = CAC_BASE;
mips_srs_init();
per_cpu_trap_init();
/*
* 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, 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);
if (current_cpu_data.cputype == CPU_R6000 ||
current_cpu_data.cputype == 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(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 (cpu_has_vce)
/* Special exception: R4[04]00 uses also the divec space. */
memcpy((void *)(CAC_BASE + 0x180), &except_vec3_r4000, 0x100);
else if (cpu_has_4kex)
memcpy((void *)(CAC_BASE + 0x180), &except_vec3_generic, 0x80);
else
memcpy((void *)(CAC_BASE + 0x080), &except_vec3_generic, 0x80);
signal_init();
#ifdef CONFIG_MIPS32_COMPAT
signal32_init();
#endif
flush_icache_range(ebase, ebase + 0x400);
flush_tlb_handlers();
}
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