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[MIPS] FPU ownership management & preemption fixes

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Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Atsushi Nemoto
2007-03-10 01:07:45 +09:00
committed by Ralf Baechle
parent c6a2f46793
commit 53dc80287d
10 changed files with 126 additions and 105 deletions
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84
arch/mips/kernel/traps.c
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@@ -610,16 +610,6 @@ asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
if (fcr31 & FPU_CSR_UNI_X) {
int sig;
preempt_disable();
#ifdef CONFIG_PREEMPT
if (!is_fpu_owner()) {
/* We might lose fpu before disabling preempt... */
own_fpu();
BUG_ON(!used_math());
restore_fp(current);
}
#endif
/*
* Unimplemented operation exception. If we've got the full
* software emulator on-board, let's use it...
@@ -630,18 +620,12 @@ asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
* register operands before invoking the emulator, which seems
* a bit extreme for what should be an infrequent event.
*/
save_fp(current);
/* Ensure 'resume' not overwrite saved fp context again. */
lose_fpu();
preempt_enable();
lose_fpu(1);
/* Run the emulator */
sig = fpu_emulator_cop1Handler (regs, &current->thread.fpu, 1);
preempt_disable();
own_fpu(); /* Using the FPU again. */
/*
* We can't allow the emulated instruction to leave any of
* the cause bit set in $fcr31.
@@ -649,9 +633,7 @@ asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
/* Restore the hardware register state */
restore_fp(current);
preempt_enable();
own_fpu(1); /* Using the FPU again. */
/* If something went wrong, signal */
if (sig)
@@ -775,12 +757,11 @@ 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:
die_if_kernel("do_cpu invoked from kernel context!", regs);
if (!cpu_has_llsc)
if (!simulate_llsc(regs))
return;
@@ -791,21 +772,30 @@ asmlinkage void do_cpu(struct pt_regs *regs)
break;
case 1:
preempt_disable();
own_fpu();
if (used_math()) { /* Using the FPU again. */
restore_fp(current);
} else { /* First time FPU user. */
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 (cpu_has_fpu) {
preempt_enable();
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;
preempt_enable();
sig = fpu_emulator_cop1Handler(regs,
&current->thread.fpu, 0);
if (sig)
@@ -1259,26 +1249,26 @@ static inline void mips_srs_init(void)
/*
* This is used by native signal handling
*/
asmlinkage int (*save_fp_context)(struct sigcontext *sc);
asmlinkage int (*restore_fp_context)(struct sigcontext *sc);
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 *sc);
extern asmlinkage int _restore_fp_context(struct sigcontext *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 *sc);
extern asmlinkage int fpu_emulator_restore_context(struct sigcontext *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 *sc)
static int smp_save_fp_context(struct sigcontext __user *sc)
{
return cpu_has_fpu
return raw_cpu_has_fpu
? _save_fp_context(sc)
: fpu_emulator_save_context(sc);
}
static int smp_restore_fp_context(struct sigcontext *sc)
static int smp_restore_fp_context(struct sigcontext __user *sc)
{
return cpu_has_fpu
return raw_cpu_has_fpu
? _restore_fp_context(sc)
: fpu_emulator_restore_context(sc);
}
@@ -1306,14 +1296,14 @@ static inline void signal_init(void)
/*
* This is used by 32-bit signal stuff on the 64-bit kernel
*/
asmlinkage int (*save_fp_context32)(struct sigcontext32 *sc);
asmlinkage int (*restore_fp_context32)(struct sigcontext32 *sc);
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 *sc);
extern asmlinkage int _restore_fp_context32(struct sigcontext32 *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 *sc);
extern asmlinkage int fpu_emulator_restore_context32(struct sigcontext32 *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)
{