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authorAtsushi Nemoto <anemo@mba.ocn.ne.jp>2007-03-10 01:07:45 +0900
committerRalf Baechle <ralf@linux-mips.org>2007-03-17 01:03:26 +0000
commit53dc80287da43b75df2fe2658651d3c5160dad8e (patch)
tree3c4c97534c379709cd2a1dae5b90df626349f21d /arch/mips/kernel/traps.c
parentc6a2f4679331206ef5d353fc9a6cda2fa4aef8c6 (diff)
[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>
Diffstat (limited to 'arch/mips/kernel/traps.c')
-rw-r--r--arch/mips/kernel/traps.c84
1 files changed, 37 insertions, 47 deletions
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 18f56a9dbcf..7d76a85422b 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -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)
{