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linux/arch/mips/kernel/traps.c
Atsushi Nemoto 53dc80287d [MIPS] FPU ownership management & preemption fixes 
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-03-17 01:03:26 +00:00

1569 lines
37 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/init.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/smp_lock.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/watch.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_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 *sp = (unsigned long *)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);
void show_code(unsigned int *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 *) regs->cp0_epc);
printk("\n");
}
static DEFINE_SPINLOCK(die_lock);
NORET_TYPE void ATTRIB_NORET 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);
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 != 0);
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);
}
asmlinkage void do_cpu(struct pt_regs *regs)
{
unsigned int cpid;
cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
switch (cpid) {
case 0:
die_if_kernel("do_cpu invoked from kernel context!", regs);
if (!cpu_has_llsc)
if (!simulate_llsc(regs))
return;
if (!simulate_rdhwr(regs))
return;
break;
case 1:
if (!test_thread_flag(TIF_ALLOW_FP_IN_KERNEL))
die_if_kernel("do_cpu invoked from kernel context!",
regs);
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) {
if (test_thread_flag(TIF_ALLOW_FP_IN_KERNEL)) {
local_irq_disable();
if (cpu_has_fpu)
regs->cp0_status |= ST0_CU1;
/*
* We must return without enabling
* interrupts to ensure keep FPU
* ownership until resume.
*/
return;
}
} else {
int sig;
sig = fpu_emulator_cop1Handler(regs,
&current->thread.fpu, 0);
if (sig)
force_sig(sig, current);
#ifdef CONFIG_MIPS_MT_FPAFF
else {
/*
* 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.
*/
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 */
}
return;
case 2:
case 3:
die_if_kernel("do_cpu invoked from kernel context!", regs);
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)
{
/*
* 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 *) 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);
}
asmlinkage void do_default_vi(struct pt_regs *regs)
{
show_regs(regs);
panic("Caught unexpected vectored interrupt.");
}
/*
* 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 void *set_vi_srs_handler(int n, void *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
if (n > 7)
printk("Vector index %d exceeds SMTC maximum\n", n);
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, void *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
write_c0_hwrena (0x0000000f); /* Allow rdhwr to all registers */
#endif
#ifdef CONFIG_MIPS_MT_SMTC
if (!secondaryTC) {
#endif /* CONFIG_MIPS_MT_SMTC */
/*
* Interrupt handling.
*/
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);
}
#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
}
#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);
if (cpu_has_dsp)
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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