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author | Atsushi Nemoto <anemo@mba.ocn.ne.jp> | 2007-03-10 01:07:45 +0900 |
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committer | Ralf Baechle <ralf@linux-mips.org> | 2007-03-17 01:03:26 +0000 |
commit | 53dc80287da43b75df2fe2658651d3c5160dad8e (patch) | |
tree | 3c4c97534c379709cd2a1dae5b90df626349f21d /arch/mips/kernel/traps.c | |
parent | c6a2f4679331206ef5d353fc9a6cda2fa4aef8c6 (diff) | |
download | kernel_samsung_smdk4412-53dc80287da43b75df2fe2658651d3c5160dad8e.zip kernel_samsung_smdk4412-53dc80287da43b75df2fe2658651d3c5160dad8e.tar.gz kernel_samsung_smdk4412-53dc80287da43b75df2fe2658651d3c5160dad8e.tar.bz2 |
[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.c | 84 |
1 files changed, 37 insertions, 47 deletions
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c index 18f56a9..7d76a85 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, ¤t->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, ¤t->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) { |