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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 | |
parent | c6a2f4679331206ef5d353fc9a6cda2fa4aef8c6 (diff) | |
download | blackbird-op-linux-53dc80287da43b75df2fe2658651d3c5160dad8e.tar.gz blackbird-op-linux-53dc80287da43b75df2fe2658651d3c5160dad8e.zip |
[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')
-rw-r--r-- | arch/mips/kernel/r2300_switch.S | 10 | ||||
-rw-r--r-- | arch/mips/kernel/r4k_switch.S | 10 | ||||
-rw-r--r-- | arch/mips/kernel/signal.c | 29 | ||||
-rw-r--r-- | arch/mips/kernel/signal32.c | 29 | ||||
-rw-r--r-- | arch/mips/kernel/traps.c | 84 |
5 files changed, 73 insertions, 89 deletions
diff --git a/arch/mips/kernel/r2300_switch.S b/arch/mips/kernel/r2300_switch.S index 656bde2e11b1..28c2e2e6af73 100644 --- a/arch/mips/kernel/r2300_switch.S +++ b/arch/mips/kernel/r2300_switch.S @@ -49,8 +49,7 @@ LEAF(resume) #ifndef CONFIG_CPU_HAS_LLSC sw zero, ll_bit #endif - mfc0 t1, CP0_STATUS - sw t1, THREAD_STATUS(a0) + mfc0 t2, CP0_STATUS cpu_save_nonscratch a0 sw ra, THREAD_REG31(a0) @@ -60,8 +59,8 @@ LEAF(resume) lw t3, TASK_THREAD_INFO(a0) lw t0, TI_FLAGS(t3) li t1, _TIF_USEDFPU - and t2, t0, t1 - beqz t2, 1f + and t1, t0 + beqz t1, 1f nor t1, zero, t1 and t0, t0, t1 @@ -74,10 +73,13 @@ LEAF(resume) li t1, ~ST0_CU1 and t0, t0, t1 sw t0, ST_OFF(t3) + /* clear thread_struct CU1 bit */ + and t2, t1 fpu_save_single a0, t0 # clobbers t0 1: + sw t2, THREAD_STATUS(a0) /* * The order of restoring the registers takes care of the race * updating $28, $29 and kernelsp without disabling ints. diff --git a/arch/mips/kernel/r4k_switch.S b/arch/mips/kernel/r4k_switch.S index cc566cf12246..c7698fd9955c 100644 --- a/arch/mips/kernel/r4k_switch.S +++ b/arch/mips/kernel/r4k_switch.S @@ -48,8 +48,7 @@ #ifndef CONFIG_CPU_HAS_LLSC sw zero, ll_bit #endif - mfc0 t1, CP0_STATUS - LONG_S t1, THREAD_STATUS(a0) + mfc0 t2, CP0_STATUS cpu_save_nonscratch a0 LONG_S ra, THREAD_REG31(a0) @@ -59,8 +58,8 @@ PTR_L t3, TASK_THREAD_INFO(a0) LONG_L t0, TI_FLAGS(t3) li t1, _TIF_USEDFPU - and t2, t0, t1 - beqz t2, 1f + and t1, t0 + beqz t1, 1f nor t1, zero, t1 and t0, t0, t1 @@ -73,10 +72,13 @@ li t1, ~ST0_CU1 and t0, t0, t1 LONG_S t0, ST_OFF(t3) + /* clear thread_struct CU1 bit */ + and t2, t1 fpu_save_double a0 t0 t1 # c0_status passed in t0 # clobbers t1 1: + LONG_S t2, THREAD_STATUS(a0) /* * The order of restoring the registers takes care of the race diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c index bf094fc4c7eb..8c3c5a5789b0 100644 --- a/arch/mips/kernel/signal.c +++ b/arch/mips/kernel/signal.c @@ -82,6 +82,7 @@ int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) { int err = 0; int i; + unsigned int used_math; err |= __put_user(regs->cp0_epc, &sc->sc_pc); @@ -104,22 +105,18 @@ int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp); } - err |= __put_user(!!used_math(), &sc->sc_used_math); + used_math = !!used_math(); + err |= __put_user(used_math, &sc->sc_used_math); - if (used_math()) { + if (used_math) { /* * Save FPU state to signal context. Signal handler * will "inherit" current FPU state. */ - preempt_disable(); - - if (!is_fpu_owner()) { - own_fpu(); - restore_fp(current); - } + own_fpu(1); + enable_fp_in_kernel(); err |= save_fp_context(sc); - - preempt_enable(); + disable_fp_in_kernel(); } return err; } @@ -188,20 +185,18 @@ int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) err |= __get_user(used_math, &sc->sc_used_math); conditional_used_math(used_math); - preempt_disable(); - - if (used_math()) { + if (used_math) { /* restore fpu context if we have used it before */ - own_fpu(); + own_fpu(0); + enable_fp_in_kernel(); if (!err) err = check_and_restore_fp_context(sc); + disable_fp_in_kernel(); } else { /* signal handler may have used FPU. Give it up. */ - lose_fpu(); + lose_fpu(0); } - preempt_enable(); - return err; } diff --git a/arch/mips/kernel/signal32.c b/arch/mips/kernel/signal32.c index 20013b6fe725..151fd2f0893a 100644 --- a/arch/mips/kernel/signal32.c +++ b/arch/mips/kernel/signal32.c @@ -181,6 +181,7 @@ static int setup_sigcontext32(struct pt_regs *regs, { int err = 0; int i; + u32 used_math; err |= __put_user(regs->cp0_epc, &sc->sc_pc); @@ -200,22 +201,18 @@ static int setup_sigcontext32(struct pt_regs *regs, err |= __put_user(mflo3(), &sc->sc_lo3); } - err |= __put_user(!!used_math(), &sc->sc_used_math); + used_math = !!used_math(); + err |= __put_user(used_math, &sc->sc_used_math); - if (used_math()) { + if (used_math) { /* * Save FPU state to signal context. Signal handler * will "inherit" current FPU state. */ - preempt_disable(); - - if (!is_fpu_owner()) { - own_fpu(); - restore_fp(current); - } + own_fpu(1); + enable_fp_in_kernel(); err |= save_fp_context32(sc); - - preempt_enable(); + disable_fp_in_kernel(); } return err; } @@ -262,20 +259,18 @@ static int restore_sigcontext32(struct pt_regs *regs, err |= __get_user(used_math, &sc->sc_used_math); conditional_used_math(used_math); - preempt_disable(); - - if (used_math()) { + if (used_math) { /* restore fpu context if we have used it before */ - own_fpu(); + own_fpu(0); + enable_fp_in_kernel(); if (!err) err = check_and_restore_fp_context32(sc); + disable_fp_in_kernel(); } else { /* signal handler may have used FPU. Give it up. */ - lose_fpu(); + lose_fpu(0); } - preempt_enable(); - return err; } diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c index 18f56a9dbcfa..7d76a85422b2 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) { |