diff options
| -rw-r--r-- | arch/x86/ia32/ia32_signal.c | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/fpu-internal.h | 520 | ||||
| -rw-r--r-- | arch/x86/include/asm/i387.h | 590 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/i387.c | 83 | ||||
| -rw-r--r-- | arch/x86/kernel/process.c | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/process_32.c | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/process_64.c | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/ptrace.c | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/signal.c | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/traps.c | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/xsave.c | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx.c | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 1 | ||||
| -rw-r--r-- | arch/x86/power/cpu.c | 1 |
15 files changed, 624 insertions, 584 deletions
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c index 65577698cab2..5563ba1cf513 100644 --- a/arch/x86/ia32/ia32_signal.c +++ b/arch/x86/ia32/ia32_signal.c @@ -24,6 +24,7 @@ #include <asm/ucontext.h> #include <asm/uaccess.h> #include <asm/i387.h> +#include <asm/fpu-internal.h> #include <asm/ptrace.h> #include <asm/ia32_unistd.h> #include <asm/user32.h> diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h new file mode 100644 index 000000000000..4fa88154e4de --- /dev/null +++ b/arch/x86/include/asm/fpu-internal.h @@ -0,0 +1,520 @@ +/* + * Copyright (C) 1994 Linus Torvalds + * + * Pentium III FXSR, SSE support + * General FPU state handling cleanups + * Gareth Hughes <gareth@valinux.com>, May 2000 + * x86-64 work by Andi Kleen 2002 + */ + +#ifndef _FPU_INTERNAL_H +#define _FPU_INTERNAL_H + +#include <linux/kernel_stat.h> +#include <linux/regset.h> +#include <linux/slab.h> +#include <asm/asm.h> +#include <asm/cpufeature.h> +#include <asm/processor.h> +#include <asm/sigcontext.h> +#include <asm/user.h> +#include <asm/uaccess.h> +#include <asm/xsave.h> + +extern unsigned int sig_xstate_size; +extern void fpu_init(void); + +DECLARE_PER_CPU(struct task_struct *, fpu_owner_task); + +extern user_regset_active_fn fpregs_active, xfpregs_active; +extern user_regset_get_fn fpregs_get, xfpregs_get, fpregs_soft_get, + xstateregs_get; +extern user_regset_set_fn fpregs_set, xfpregs_set, fpregs_soft_set, + xstateregs_set; + + +/* + * xstateregs_active == fpregs_active. Please refer to the comment + * at the definition of fpregs_active. + */ +#define xstateregs_active fpregs_active + +extern struct _fpx_sw_bytes fx_sw_reserved; +#ifdef CONFIG_IA32_EMULATION +extern unsigned int sig_xstate_ia32_size; +extern struct _fpx_sw_bytes fx_sw_reserved_ia32; +struct _fpstate_ia32; +struct _xstate_ia32; +extern int save_i387_xstate_ia32(void __user *buf); +extern int restore_i387_xstate_ia32(void __user *buf); +#endif + +#ifdef CONFIG_MATH_EMULATION +extern void finit_soft_fpu(struct i387_soft_struct *soft); +#else +static inline void finit_soft_fpu(struct i387_soft_struct *soft) {} +#endif + +#define X87_FSW_ES (1 << 7) /* Exception Summary */ + +static __always_inline __pure bool use_xsaveopt(void) +{ + return static_cpu_has(X86_FEATURE_XSAVEOPT); +} + +static __always_inline __pure bool use_xsave(void) +{ + return static_cpu_has(X86_FEATURE_XSAVE); +} + +static __always_inline __pure bool use_fxsr(void) +{ + return static_cpu_has(X86_FEATURE_FXSR); +} + +extern void __sanitize_i387_state(struct task_struct *); + +static inline void sanitize_i387_state(struct task_struct *tsk) +{ + if (!use_xsaveopt()) + return; + __sanitize_i387_state(tsk); +} + +#ifdef CONFIG_X86_64 +static inline int fxrstor_checking(struct i387_fxsave_struct *fx) +{ + int err; + + /* See comment in fxsave() below. */ +#ifdef CONFIG_AS_FXSAVEQ + asm volatile("1: fxrstorq %[fx]\n\t" + "2:\n" + ".section .fixup,\"ax\"\n" + "3: movl $-1,%[err]\n" + " jmp 2b\n" + ".previous\n" + _ASM_EXTABLE(1b, 3b) + : [err] "=r" (err) + : [fx] "m" (*fx), "0" (0)); +#else + asm volatile("1: rex64/fxrstor (%[fx])\n\t" + "2:\n" + ".section .fixup,\"ax\"\n" + "3: movl $-1,%[err]\n" + " jmp 2b\n" + ".previous\n" + _ASM_EXTABLE(1b, 3b) + : [err] "=r" (err) + : [fx] "R" (fx), "m" (*fx), "0" (0)); +#endif + return err; +} + +static inline int fxsave_user(struct i387_fxsave_struct __user *fx) +{ + int err; + + /* + * Clear the bytes not touched by the fxsave and reserved + * for the SW usage. + */ + err = __clear_user(&fx->sw_reserved, + sizeof(struct _fpx_sw_bytes)); + if (unlikely(err)) + return -EFAULT; + + /* See comment in fxsave() below. */ +#ifdef CONFIG_AS_FXSAVEQ + asm volatile("1: fxsaveq %[fx]\n\t" + "2:\n" + ".section .fixup,\"ax\"\n" + "3: movl $-1,%[err]\n" + " jmp 2b\n" + ".previous\n" + _ASM_EXTABLE(1b, 3b) + : [err] "=r" (err), [fx] "=m" (*fx) + : "0" (0)); +#else + asm volatile("1: rex64/fxsave (%[fx])\n\t" + "2:\n" + ".section .fixup,\"ax\"\n" + "3: movl $-1,%[err]\n" + " jmp 2b\n" + ".previous\n" + _ASM_EXTABLE(1b, 3b) + : [err] "=r" (err), "=m" (*fx) + : [fx] "R" (fx), "0" (0)); +#endif + if (unlikely(err) && + __clear_user(fx, sizeof(struct i387_fxsave_struct))) + err = -EFAULT; + /* No need to clear here because the caller clears USED_MATH */ + return err; +} + +static inline void fpu_fxsave(struct fpu *fpu) +{ + /* Using "rex64; fxsave %0" is broken because, if the memory operand + uses any extended registers for addressing, a second REX prefix + will be generated (to the assembler, rex64 followed by semicolon + is a separate instruction), and hence the 64-bitness is lost. */ + +#ifdef CONFIG_AS_FXSAVEQ + /* Using "fxsaveq %0" would be the ideal choice, but is only supported + starting with gas 2.16. */ + __asm__ __volatile__("fxsaveq %0" + : "=m" (fpu->state->fxsave)); +#else + /* Using, as a workaround, the properly prefixed form below isn't + accepted by any binutils version so far released, complaining that + the same type of prefix is used twice if an extended register is + needed for addressing (fix submitted to mainline 2005-11-21). + asm volatile("rex64/fxsave %0" + : "=m" (fpu->state->fxsave)); + This, however, we can work around by forcing the compiler to select + an addressing mode that doesn't require extended registers. */ + asm volatile("rex64/fxsave (%[fx])" + : "=m" (fpu->state->fxsave) + : [fx] "R" (&fpu->state->fxsave)); +#endif +} + +#else /* CONFIG_X86_32 */ + +/* perform fxrstor iff the processor has extended states, otherwise frstor */ +static inline int fxrstor_checking(struct i387_fxsave_struct *fx) +{ + /* + * The "nop" is needed to make the instructions the same + * length. + */ + alternative_input( + "nop ; frstor %1", + "fxrstor %1", + X86_FEATURE_FXSR, + "m" (*fx)); + + return 0; +} + +static inline void fpu_fxsave(struct fpu *fpu) +{ + asm volatile("fxsave %[fx]" + : [fx] "=m" (fpu->state->fxsave)); +} + +#endif /* CONFIG_X86_64 */ + +/* + * These must be called with preempt disabled. Returns + * 'true' if the FPU state is still intact. + */ +static inline int fpu_save_init(struct fpu *fpu) +{ + if (use_xsave()) { + fpu_xsave(fpu); + + /* + * xsave header may indicate the init state of the FP. + */ + if (!(fpu->state->xsave.xsave_hdr.xstate_bv & XSTATE_FP)) + return 1; + } else if (use_fxsr()) { + fpu_fxsave(fpu); + } else { + asm volatile("fnsave %[fx]; fwait" + : [fx] "=m" (fpu->state->fsave)); + return 0; + } + + /* + * If exceptions are pending, we need to clear them so + * that we don't randomly get exceptions later. + * + * FIXME! Is this perhaps only true for the old-style + * irq13 case? Maybe we could leave the x87 state + * intact otherwise? + */ + if (unlikely(fpu->state->fxsave.swd & X87_FSW_ES)) { + asm volatile("fnclex"); + return 0; + } + return 1; +} + +static inline int __save_init_fpu(struct task_struct *tsk) +{ + return fpu_save_init(&tsk->thread.fpu); +} + +static inline int fpu_fxrstor_checking(struct fpu *fpu) +{ + return fxrstor_checking(&fpu->state->fxsave); +} + +static inline int fpu_restore_checking(struct fpu *fpu) +{ + if (use_xsave()) + return fpu_xrstor_checking(fpu); + else + return fpu_fxrstor_checking(fpu); +} + +static inline int restore_fpu_checking(struct task_struct *tsk) +{ + /* AMD K7/K8 CPUs don't save/restore FDP/FIP/FOP unless an exception + is pending. Clear the x87 state here by setting it to fixed + values. "m" is a random variable that should be in L1 */ + alternative_input( + ASM_NOP8 ASM_NOP2, + "emms\n\t" /* clear stack tags */ + "fildl %P[addr]", /* set F?P to defined value */ + X86_FEATURE_FXSAVE_LEAK, + [addr] "m" (tsk->thread.fpu.has_fpu)); + + return fpu_restore_checking(&tsk->thread.fpu); +} + +/* + * Software FPU state helpers. Careful: these need to + * be preemption protection *and* they need to be + * properly paired with the CR0.TS changes! + */ +static inline int __thread_has_fpu(struct task_struct *tsk) +{ + return tsk->thread.fpu.has_fpu; +} + +/* Must be paired with an 'stts' after! */ +static inline void __thread_clear_has_fpu(struct task_struct *tsk) +{ + tsk->thread.fpu.has_fpu = 0; + percpu_write(fpu_owner_task, NULL); +} + +/* Must be paired with a 'clts' before! */ +static inline void __thread_set_has_fpu(struct task_struct *tsk) +{ + tsk->thread.fpu.has_fpu = 1; + percpu_write(fpu_owner_task, tsk); +} + +/* + * Encapsulate the CR0.TS handling together with the + * software flag. + * + * These generally need preemption protection to work, + * do try to avoid using these on their own. + */ +static inline void __thread_fpu_end(struct task_struct *tsk) +{ + __thread_clear_has_fpu(tsk); + stts(); +} + +static inline void __thread_fpu_begin(struct task_struct *tsk) +{ + clts(); + __thread_set_has_fpu(tsk); +} + +/* + * FPU state switching for scheduling. + * + * This is a two-stage process: + * + * - switch_fpu_prepare() saves the old state and + * sets the new state of the CR0.TS bit. This is + * done within the context of the old process. + * + * - switch_fpu_finish() restores the new state as + * necessary. + */ +typedef struct { int preload; } fpu_switch_t; + +/* + * FIXME! We could do a totally lazy restore, but we need to + * add a per-cpu "this was the task that last touched the FPU + * on this CPU" variable, and the task needs to have a "I last + * touched the FPU on this CPU" and check them. + * + * We don't do that yet, so "fpu_lazy_restore()" always returns + * false, but some day.. + */ +static inline int fpu_lazy_restore(struct task_struct *new, unsigned int cpu) +{ + return new == percpu_read_stable(fpu_owner_task) && + cpu == new->thread.fpu.last_cpu; +} + +static inline fpu_switch_t switch_fpu_prepare(struct task_struct *old, struct task_struct *new, int cpu) +{ + fpu_switch_t fpu; + + fpu.preload = tsk_used_math(new) && new->fpu_counter > 5; + if (__thread_has_fpu(old)) { + if (!__save_init_fpu(old)) + cpu = ~0; + old->thread.fpu.last_cpu = cpu; + old->thread.fpu.has_fpu = 0; /* But leave fpu_owner_task! */ + + /* Don't change CR0.TS if we just switch! */ + if (fpu.preload) { + new->fpu_counter++; + __thread_set_has_fpu(new); + prefetch(new->thread.fpu.state); + } else + stts(); + } else { + old->fpu_counter = 0; + old->thread.fpu.last_cpu = ~0; + if (fpu.preload) { + new->fpu_counter++; + if (fpu_lazy_restore(new, cpu)) + fpu.preload = 0; + else + prefetch(new->thread.fpu.state); + __thread_fpu_begin(new); + } + } + return fpu; +} + +/* + * By the time this gets called, we've already cleared CR0.TS and + * given the process the FPU if we are going to preload the FPU + * state - all we need to do is to conditionally restore the register + * state itself. + */ +static inline void switch_fpu_finish(struct task_struct *new, fpu_switch_t fpu) +{ + if (fpu.preload) { + if (unlikely(restore_fpu_checking(new))) + __thread_fpu_end(new); + } +} + +/* + * Signal frame handlers... + */ +extern int save_i387_xstate(void __user *buf); +extern int restore_i387_xstate(void __user *buf); + +static inline void __clear_fpu(struct task_struct *tsk) +{ + if (__thread_has_fpu(tsk)) { + /* Ignore delayed exceptions from user space */ + asm volatile("1: fwait\n" + "2:\n" + _ASM_EXTABLE(1b, 2b)); + __thread_fpu_end(tsk); + } +} + +/* + * The actual user_fpu_begin/end() functions + * need to be preemption-safe. + * + * NOTE! user_fpu_end() must be used only after you + * have saved the FP state, and user_fpu_begin() must + * be used only immediately before restoring it. + * These functions do not do any save/restore on + * their own. + */ +static inline void user_fpu_end(void) +{ + preempt_disable(); + __thread_fpu_end(current); + preempt_enable(); +} + +static inline void user_fpu_begin(void) +{ + preempt_disable(); + if (!user_has_fpu()) + __thread_fpu_begin(current); + preempt_enable(); +} + +/* + * These disable preemption on their own and are safe + */ +static inline void save_init_fpu(struct task_struct *tsk) +{ + WARN_ON_ONCE(!__thread_has_fpu(tsk)); + preempt_disable(); + __save_init_fpu(tsk); + __thread_fpu_end(tsk); + preempt_enable(); +} + +static inline void clear_fpu(struct task_struct *tsk) +{ + preempt_disable(); + __clear_fpu(tsk); + preempt_enable(); +} + +/* + * i387 state interaction + */ +static inline unsigned short get_fpu_cwd(struct task_struct *tsk) +{ + if (cpu_has_fxsr) { + return tsk->thread.fpu.state->fxsave.cwd; + } else { + return (unsigned short)tsk->thread.fpu.state->fsave.cwd; + } +} + +static inline unsigned short get_fpu_swd(struct task_struct *tsk) +{ + if (cpu_has_fxsr) { + return tsk->thread.fpu.state->fxsave.swd; + } else { + return (unsigned short)tsk->thread.fpu.state->fsave.swd; + } +} + +static inline unsigned short get_fpu_mxcsr(struct task_struct *tsk) +{ + if (cpu_has_xmm) { + return tsk->thread.fpu.state->fxsave.mxcsr; + } else { + return MXCSR_DEFAULT; + } +} + +static bool fpu_allocated(struct fpu *fpu) +{ + return fpu->state != NULL; +} + +static inline int fpu_alloc(struct fpu *fpu) +{ + if (fpu_allocated(fpu)) + return 0; + fpu->state = kmem_cache_alloc(task_xstate_cachep, GFP_KERNEL); + if (!fpu->state) + return -ENOMEM; + WARN_ON((unsigned long)fpu->state & 15); + return 0; +} + +static inline void fpu_free(struct fpu *fpu) +{ + if (fpu->state) { + kmem_cache_free(task_xstate_cachep, fpu->state); + fpu->state = NULL; + } +} + +static inline void fpu_copy(struct fpu *dst, struct fpu *src) +{ + memcpy(dst->state, src->state, xstate_size); +} + +extern void fpu_finit(struct fpu *fpu); + +#endif diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h index 247904945d3f..7ce0798b1b26 100644 --- a/arch/x86/include/asm/i387.h +++ b/arch/x86/include/asm/i387.h @@ -13,476 +13,19 @@ #ifndef __ASSEMBLY__ #include <linux/sched.h> -#include <linux/kernel_stat.h> -#include <linux/regset.h> #include <linux/hardirq.h> -#include <linux/slab.h> -#include <asm/asm.h> -#include <asm/cpufeature.h> -#include <asm/processor.h> -#include <asm/sigcontext.h> -#include <asm/user.h> -#include <asm/uaccess.h> -#include <asm/xsave.h> +#include <asm/system.h> + +struct pt_regs; +struct user_i387_struct; -extern unsigned int sig_xstate_size; -extern void fpu_init(void); -extern void mxcsr_feature_mask_init(void); extern int init_fpu(struct task_struct *child); -extern void math_state_restore(void); extern int dump_fpu(struct pt_regs *, struct user_i387_struct *); +extern void math_state_restore(void); -DECLARE_PER_CPU(struct task_struct *, fpu_owner_task); - -extern user_regset_active_fn fpregs_active, xfpregs_active; -extern user_regset_get_fn fpregs_get, xfpregs_get, fpregs_soft_get, - xstateregs_get; -extern user_regset_set_fn fpregs_set, xfpregs_set, fpregs_soft_set, - xstateregs_set; - -/* - * xstateregs_active == fpregs_active. Please refer to the comment - * at the definition of fpregs_active. - */ -#define xstateregs_active fpregs_active - -extern struct _fpx_sw_bytes fx_sw_reserved; -#ifdef CONFIG_IA32_EMULATION -extern unsigned int sig_xstate_ia32_size; -extern struct _fpx_sw_bytes fx_sw_reserved_ia32; -struct _fpstate_ia32; -struct _xstate_ia32; -extern int save_i387_xstate_ia32(void __user *buf); -extern int restore_i387_xstate_ia32(void __user *buf); -#endif - -#ifdef CONFIG_MATH_EMULATION -extern void finit_soft_fpu(struct i387_soft_struct *soft); -#else -static inline void finit_soft_fpu(struct i387_soft_struct *soft) {} -#endif - -#define X87_FSW_ES (1 << 7) /* Exception Summary */ - -static __always_inline __pure bool use_xsaveopt(void) -{ - return static_cpu_has(X86_FEATURE_XSAVEOPT); -} - -static __always_inline __pure bool use_xsave(void) -{ - return static_cpu_has(X86_FEATURE_XSAVE); -} - -static __always_inline __pure bool use_fxsr(void) -{ - return static_cpu_has(X86_FEATURE_FXSR); -} - -extern void __sanitize_i387_state(struct task_struct *); - -static inline void sanitize_i387_state(struct task_struct *tsk) -{ - if (!use_xsaveopt()) - return; - __sanitize_i387_state(tsk); -} - -#ifdef CONFIG_X86_64 -static inline int fxrstor_checking(struct i387_fxsave_struct *fx) -{ - int err; - - /* See comment in fxsave() below. */ -#ifdef CONFIG_AS_FXSAVEQ - asm volatile("1: fxrstorq %[fx]\n\t" - "2:\n" - ".section .fixup,\"ax\"\n" - "3: movl $-1,%[err]\n" - " jmp 2b\n" - ".previous\n" - _ASM_EXTABLE(1b, 3b) - : [err] "=r" (err) - : [fx] "m" (*fx), "0" (0)); -#else - asm volatile("1: rex64/fxrstor (%[fx])\n\t" - "2:\n" - ".section .fixup,\"ax\"\n" - "3: movl $-1,%[err]\n" - " jmp 2b\n" - ".previous\n" - _ASM_EXTABLE(1b, 3b) - : [err] "=r" (err) - : [fx] "R" (fx), "m" (*fx), "0" (0)); -#endif - return err; -} - -static inline int fxsave_user(struct i387_fxsave_struct __user *fx) -{ - int err; - - /* - * Clear the bytes not touched by the fxsave and reserved - * for the SW usage. - */ - err = __clear_user(&fx->sw_reserved, - sizeof(struct _fpx_sw_bytes)); - if (unlikely(err)) - return -EFAULT; - - /* See comment in fxsave() below. */ -#ifdef CONFIG_AS_FXSAVEQ - asm volatile("1: fxsaveq %[fx]\n\t" - "2:\n" - ".section .fixup,\"ax\"\n" - "3: movl $-1,%[err]\n" - " jmp 2b\n" - ".previous\n" - _ASM_EXTABLE(1b, 3b) - : [err] "=r" (err), [fx] "=m" (*fx) - : "0" (0)); -#else - asm volatile("1: rex64/fxsave (%[fx])\n\t" - "2:\n" - ".section .fixup,\"ax\"\n" - "3: movl $-1,%[err]\n" - " jmp 2b\n" - ".previous\n" - _ASM_EXTABLE(1b, 3b) - : [err] "=r" (err), "=m" (*fx) - : [fx] "R" (fx), "0" (0)); -#endif - if (unlikely(err) && - __clear_user(fx, sizeof(struct i387_fxsave_struct))) - err = -EFAULT; - /* No need to clear here because the caller clears USED_MATH */ - return err; -} - -static inline void fpu_fxsave(struct fpu *fpu) -{ - /* Using "rex64; fxsave %0" is broken because, if the memory operand - uses any extended registers for addressing, a second REX prefix - will be generated (to the assembler, rex64 followed by semicolon - is a separate instruction), and hence the 64-bitness is lost. */ - -#ifdef CONFIG_AS_FXSAVEQ - /* Using "fxsaveq %0" would be the ideal choice, but is only supported - starting with gas 2.16. */ - __asm__ __volatile__("fxsaveq %0" - : "=m" (fpu->state->fxsave)); -#else - /* Using, as a workaround, the properly prefixed form below isn't - accepted by any binutils version so far released, complaining that - the same type of prefix is used twice if an extended register is - needed for addressing (fix submitted to mainline 2005-11-21). - asm volatile("rex64/fxsave %0" - : "=m" (fpu->state->fxsave)); - This, however, we can work around by forcing the compiler to select - an addressing mode that doesn't require extended registers. */ - asm volatile("rex64/fxsave (%[fx])" - : "=m" (fpu->state->fxsave) - : [fx] "R" (&fpu->state->fxsave)); -#endif -} - -#else /* CONFIG_X86_32 */ - -/* perform fxrstor iff the processor has extended states, otherwise frstor */ -static inline int fxrstor_checking(struct i387_fxsave_struct *fx) -{ - /* - * The "nop" is needed to make the instructions the same - * length. - */ - alternative_input( - "nop ; frstor %1", - "fxrstor %1", - X86_FEATURE_FXSR, - "m" (*fx)); - - return 0; -} - -static inline void fpu_fxsave(struct fpu *fpu) -{ - asm volatile("fxsave %[fx]" - : [fx] "=m" (fpu->state->fxsave)); -} - -#endif /* CONFIG_X86_64 */ - -/* - * These must be called with preempt disabled. Returns - * 'true' if the FPU state is still intact. - */ -static inline int fpu_save_init(struct fpu *fpu) -{ - if (use_xsave()) { - fpu_xsave(fpu); - - /* - * xsave header may indicate the init state of the FP. - */ - if (!(fpu->state->xsave.xsave_hdr.xstate_bv & XSTATE_FP)) - return 1; - } else if (use_fxsr()) { - fpu_fxsave(fpu); - } else { - asm volatile("fnsave %[fx]; fwait" - : [fx] "=m" (fpu->state->fsave)); - return 0; - } - - /* - * If exceptions are pending, we need to clear them so - * that we don't randomly get exceptions later. - * - * FIXME! Is this perhaps only true for the old-style - * irq13 case? Maybe we could leave the x87 state - * intact otherwise? - */ - if (unlikely(fpu->state->fxsave.swd & X87_FSW_ES)) { - asm volatile("fnclex"); - return 0; - } - return 1; -} - -static inline int __save_init_fpu(struct task_struct *tsk) -{ - return fpu_save_init(&tsk->thread.fpu); -} - -static inline int fpu_fxrstor_checking(struct fpu *fpu) -{ - return fxrstor_checking(&fpu->state->fxsave); -} - -static inline int fpu_restore_checking(struct fpu *fpu) -{ - if (use_xsave()) - return fpu_xrstor_checking(fpu); - else - return fpu_fxrstor_checking(fpu); -} - -static inline int restore_fpu_checking(struct task_struct *tsk) -{ - /* AMD K7/K8 CPUs don't save/restore FDP/FIP/FOP unless an exception - is pending. Clear the x87 state here by setting it to fixed - values. "m" is a random variable that should be in L1 */ - alternative_input( - ASM_NOP8 ASM_NOP2, - "emms\n\t" /* clear stack tags */ - "fildl %P[addr]", /* set F?P to defined value */ - X86_FEATURE_FXSAVE_LEAK, - [addr] "m" (tsk->thread.fpu.has_fpu)); - - return fpu_restore_checking(&tsk->thread.fpu); -} - -/* - * Software FPU state helpers. Careful: these need to - * be preemption protection *and* they need to be - * properly paired with the CR0.TS changes! - */ -static inline int __thread_has_fpu(struct task_struct *tsk) -{ - return tsk->thread.fpu.has_fpu; -} - -/* Must be paired with an 'stts' after! */ -static inline void __thread_clear_has_fpu(struct task_struct *tsk) -{ - tsk->thread.fpu.has_fpu = 0; - percpu_write(fpu_owner_task, NULL); -} - -/* Must be paired with a 'clts' before! */ -static inline void __thread_set_has_fpu(struct task_struct *tsk) -{ - tsk->thread.fpu.has_fpu = 1; - percpu_write(fpu_owner_task, tsk); -} - -/* - * Encapsulate the CR0.TS handling together with the - * software flag. - * - * These generally need preemption protection to work, - * do try to avoid using these on their own. - */ -static inline void __thread_fpu_end(struct task_struct *tsk) -{ - __thread_clear_has_fpu(tsk); - stts(); -} - -static inline void __thread_fpu_begin(struct task_struct *tsk) -{ - clts(); - __thread_set_has_fpu(tsk); -} - -/* - * FPU state switching for scheduling. - * - * This is a two-stage process: - * - * - switch_fpu_prepare() saves the old state and - * sets the new state of the CR0.TS bit. This is - * done within the context of the old process. - * - * - switch_fpu_finish() restores the new state as - * necessary. - */ -typedef struct { int preload; } fpu_switch_t; - -/* - * FIXME! We could do a totally lazy restore, but we need to - * add a per-cpu "this was the task that last touched the FPU - * on this CPU" variable, and the task needs to have a "I last - * touched the FPU on this CPU" and check them. - * - * We don't do that yet, so "fpu_lazy_restore()" always returns - * false, but some day.. - */ -static inline int fpu_lazy_restore(struct task_struct *new, unsigned int cpu) -{ - return new == percpu_read_stable(fpu_owner_task) && - cpu == new->thread.fpu.last_cpu; -} - -static inline fpu_switch_t switch_fpu_prepare(struct task_struct *old, struct task_struct *new, int cpu) -{ - fpu_switch_t fpu; - - fpu.preload = tsk_used_math(new) && new->fpu_counter > 5; - if (__thread_has_fpu(old)) { - if (!__save_init_fpu(old)) - cpu = ~0; - old->thread.fpu.last_cpu = cpu; - old->thread.fpu.has_fpu = 0; /* But leave fpu_owner_task! */ - - /* Don't change CR0.TS if we just switch! */ - if (fpu.preload) { - new->fpu_counter++; - __thread_set_has_fpu(new); - prefetch(new->thread.fpu.state); - } else - stts(); - } else { - old->fpu_counter = 0; - old->thread.fpu.last_cpu = ~0; - if (fpu.preload) { - new->fpu_counter++; - if (fpu_lazy_restore(new, cpu)) - fpu.preload = 0; - else - prefetch(new->thread.fpu.state); - __thread_fpu_begin(new); - } - } - return fpu; -} - -/* - * By the time this gets called, we've already cleared CR0.TS and - * given the process the FPU if we are going to preload the FPU - * state - all we need to do is to conditionally restore the register - * state itself. - */ -static inline void switch_fpu_finish(struct task_struct *new, fpu_switch_t fpu) -{ - if (fpu.preload) { - if (unlikely(restore_fpu_checking(new))) - __thread_fpu_end(new); - } -} - -/* - * Signal frame handlers... - */ -extern int save_i387_xstate(void __user *buf); -extern int restore_i387_xstate(void __user *buf); - -static inline void __clear_fpu(struct task_struct *tsk) -{ - if (__thread_has_fpu(tsk)) { - /* Ignore delayed exceptions from user space */ - asm volatile("1: fwait\n" - "2:\n" - _ASM_EXTABLE(1b, 2b)); - __thread_fpu_end(tsk); - } -} - -/* - * Were we in an interrupt that interrupted kernel mode? - * - * We can do a kernel_fpu_begin/end() pair *ONLY* if that - * pair does nothing at all: the thread must not have fpu (so - * that we don't try to save the FPU state), and TS must - * be set (so that the clts/stts pair does nothing that is - * visible in the interrupted kernel thread). - */ -static inline bool interrupted_kernel_fpu_idle(void) -{ - return !__thread_has_fpu(current) && - (read_cr0() & X86_CR0_TS); -} - -/* - * Were we in user mode (or vm86 mode) when we were - * interrupted? - * - * Doing kernel_fpu_begin/end() is ok if we are running - * in an interrupt context from user mode - we'll just - * save the FPU state as required. - */ -static inline bool interrupted_user_mode(void) -{ - struct pt_regs *regs = get_irq_regs(); - return regs && user_mode_vm(regs); -} - -/* - * Can we use the FPU in kernel mode with the - * whole "kernel_fpu_begin/end()" sequence? - * - * It's always ok in process context (ie "not interrupt") - * but it is sometimes ok even from an irq. - */ -static inline bool irq_fpu_usable(void) -{ - return !in_interrupt() || - interrupted_user_mode() || - interrupted_kernel_fpu_idle(); -} - -static inline void kernel_fpu_begin(void) -{ - struct task_struct *me = current; - - WARN_ON_ONCE(!irq_fpu_usable()); - preempt_disable(); - if (__thread_has_fpu(me)) { - __save_init_fpu(me); - __thread_clear_has_fpu(me); - /* We do 'stts()' in kernel_fpu_end() */ - } else { - percpu_write(fpu_owner_task, NULL); - clts(); - } -} - -static inline void kernel_fpu_end(void) -{ - stts(); - preempt_enable(); -} +extern bool irq_fpu_usable(void); +extern void kernel_fpu_begin(void); +extern void kernel_fpu_end(void); /* * Some instructions like VIA's padlock instructions generate a spurious @@ -524,126 +67,13 @@ static inline void irq_ts_restore(int TS_state) * we can just assume we have FPU access - typically * to save the FP state - we'll just take a #NM * fault and get the FPU access back. - * - * The actual user_fpu_begin/end() functions - * need to be preemption-safe, though. - * - * NOTE! user_fpu_end() must be used only after you - * have saved the FP state, and user_fpu_begin() must - * be used only immediately before restoring it. - * These functions do not do any save/restore on - * their own. */ static inline int user_has_fpu(void) { - return __thread_has_fpu(current); -} - -static inline void user_fpu_end(void) -{ - preempt_disable(); - __thread_fpu_end(current); - preempt_enable(); -} - -static inline void user_fpu_begin(void) -{ - preempt_disable(); - if (!user_has_fpu()) - __thread_fpu_begin(current); - preempt_enable(); -} - -/* - * These disable preemption on their own and are safe - */ -static inline void save_init_fpu(struct task_struct *tsk) -{ - WARN_ON_ONCE(!__thread_has_fpu(tsk)); - preempt_disable(); - __save_init_fpu(tsk); - __thread_fpu_end(tsk); - preempt_enable(); -} - -static inline void unlazy_fpu(struct task_struct *tsk) -{ - preempt_disable(); - if (__thread_has_fpu(tsk)) { - __save_init_fpu(tsk); - __thread_fpu_end(tsk); - } else - tsk->fpu_counter = 0; - preempt_enable(); -} - -static inline void clear_fpu(struct task_struct *tsk) -{ - preempt_disable(); - __clear_fpu(tsk); - preempt_enable(); -} - -/* - * i387 state interaction - */ -static inline unsigned short get_fpu_cwd(struct task_struct *tsk) -{ - if (cpu_has_fxsr) { - return tsk->thread.fpu.state->fxsave.cwd; - } else { - return (unsigned short)tsk->thread.fpu.state->fsave.cwd; - } -} - -static inline unsigned short get_fpu_swd(struct task_struct *tsk) -{ - if (cpu_has_fxsr) { - return tsk->thread.fpu.state->fxsave.swd; - } else { - return (unsigned short)tsk->thread.fpu.state->fsave.swd; - } -} - -static inline unsigned short get_fpu_mxcsr(struct task_struct *tsk) -{ - if (cpu_has_xmm) { - return tsk->thread.fpu.state->fxsave.mxcsr; - } else { - return MXCSR_DEFAULT; - } -} - -static bool fpu_allocated(struct fpu *fpu) -{ - return fpu->state != NULL; -} - -static inline int fpu_alloc(struct fpu *fpu) -{ - if (fpu_allocated(fpu)) - return 0; - fpu->state = kmem_cache_alloc(task_xstate_cachep, GFP_KERNEL); - if (!fpu->state) - return -ENOMEM; - WARN_ON((unsigned long)fpu->state & 15); - return 0; -} - -static inline void fpu_free(struct fpu *fpu) -{ - if (fpu->state) { - kmem_cache_free(task_xstate_cachep, fpu->state); - fpu->state = NULL; - } -} - -static inline void fpu_copy(struct fpu *dst, struct fpu *src) -{ - memcpy(dst->state, src->state, xstate_size); + return current->thread.fpu.has_fpu; } -extern void fpu_finit(struct fpu *fpu); +extern void unlazy_fpu(struct task_struct *tsk); #endif /* __ASSEMBLY__ */ diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index b3e0081f9a2b..ade9c794ed98 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -28,6 +28,7 @@ #include <asm/apic.h> #include <asm/desc.h> #include <asm/i387.h> +#include <asm/fpu-internal.h> #include <asm/mtrr.h> #include <linux/numa.h> #include <asm/asm.h> @@ -1045,7 +1046,6 @@ DEFINE_PER_CPU(char *, irq_stack_ptr) = DEFINE_PER_CPU(unsigned int, irq_count) = -1; DEFINE_PER_CPU(struct task_struct *, fpu_owner_task); -EXPORT_PER_CPU_SYMBOL(fpu_owner_task); /* * Special IST stacks which the CPU switches to when it calls @@ -1115,7 +1115,6 @@ void debug_stack_reset(void) DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task; EXPORT_PER_CPU_SYMBOL(current_task); DEFINE_PER_CPU(struct task_struct *, fpu_owner_task); -EXPORT_PER_CPU_SYMBOL(fpu_owner_task); #ifdef CONFIG_CC_STACKPROTECTOR DEFINE_PER_CPU_ALIGNED(struct stack_canary, stack_canary); diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c index 739d8598f789..7734bcbb5a3a 100644 --- a/arch/x86/kernel/i387.c +++ b/arch/x86/kernel/i387.c @@ -16,6 +16,7 @@ #include <asm/uaccess.h> #include <asm/ptrace.h> #include <asm/i387.h> +#include <asm/fpu-internal.h> #include <asm/user.h> #ifdef CONFIG_X86_64 @@ -32,6 +33,86 @@ # define user32_fxsr_struct user_fxsr_struct #endif +/* + * Were we in an interrupt that interrupted kernel mode? + * + * We can do a kernel_fpu_begin/end() pair *ONLY* if that + * pair does nothing at all: the thread must not have fpu (so + * that we don't try to save the FPU state), and TS must + * be set (so that the clts/stts pair does nothing that is + * visible in the interrupted kernel thread). + */ +static inline bool interrupted_kernel_fpu_idle(void) +{ + return !__thread_has_fpu(current) && + (read_cr0() & X86_CR0_TS); +} + +/* + * Were we in user mode (or vm86 mode) when we were + * interrupted? + * + * Doing kernel_fpu_begin/end() is ok if we are running + * in an interrupt context from user mode - we'll just + * save the FPU state as required. + */ +static inline bool interrupted_user_mode(void) +{ + struct pt_regs *regs = get_irq_regs(); + return regs && user_mode_vm(regs); +} + +/* + * Can we use the FPU in kernel mode with the + * whole "kernel_fpu_begin/end()" sequence? + * + * It's always ok in process context (ie "not interrupt") + * but it is sometimes ok even from an irq. + */ +bool irq_fpu_usable(void) +{ + return !in_interrupt() || + interrupted_user_mode() || + interrupted_kernel_fpu_idle(); +} +EXPORT_SYMBOL(irq_fpu_usable); + +void kernel_fpu_begin(void) +{ + struct task_struct *me = current; + + WARN_ON_ONCE(!irq_fpu_usable()); + preempt_disable(); + if (__thread_has_fpu(me)) { + __save_init_fpu(me); + __thread_clear_has_fpu(me); + /* We do 'stts()' in kernel_fpu_end() */ + } else { + percpu_write(fpu_owner_task, NULL); + clts(); + } +} +EXPORT_SYMBOL(kernel_fpu_begin); + +void kernel_fpu_end(void) +{ + stts(); + preempt_enable(); +} +EXPORT_SYMBOL(kernel_fpu_end); + +void unlazy_fpu(struct task_struct *tsk) +{ + preempt_disable(); + if (__thread_has_fpu(tsk)) { + __save_init_fpu(tsk); + __thread_fpu_end(tsk); + } else + tsk->fpu_counter = 0; + preempt_enable(); +} +EXPORT_SYMBOL(unlazy_fpu); + #ifdef CONFIG_MATH_EMULATION # define HAVE_HWFP (boot_cpu_data.hard_math) #else @@ -44,7 +125,7 @@ EXPORT_SYMBOL_GPL(xstate_size); unsigned int sig_xstate_ia32_size = sizeof(struct _fpstate_ia32); static struct i387_fxsave_struct fx_scratch __cpuinitdata; -void __cpuinit mxcsr_feature_mask_init(void) +static void __cpuinit mxcsr_feature_mask_init(void) { unsigned long mask = 0; diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 44eefde92109..14baf78d5a1f 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -21,6 +21,7 @@ #include <asm/idle.h> #include <asm/uaccess.h> #include <asm/i387.h> +#include <asm/fpu-internal.h> #include <asm/debugreg.h> struct kmem_cache *task_xstate_cachep; diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index 49888fefe794..9d7d4842bfaf 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -45,6 +45,7 @@ #include <asm/ldt.h> #include <asm/processor.h> #include <asm/i387.h> +#include <asm/fpu-internal.h> #include <asm/desc.h> #ifdef CONFIG_MATH_EMULATION #include <asm/math_emu.h> diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 442e7bfe10ae..292da13fc5aa 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -43,6 +43,7 @@ #include <asm/system.h> #include <asm/processor.h> #include <asm/i387.h> +#include <asm/fpu-internal.h> #include <asm/mmu_context.h> #include <asm/prctl.h> #include <asm/desc.h> diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index 50267386b766..78f05e438be5 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -27,6 +27,7 @@ #include <asm/system.h> #include <asm/processor.h> #include <asm/i387.h> +#include <asm/fpu-internal.h> #include <asm/debugreg.h> #include <asm/ldt.h> #include <asm/desc.h> diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index 46a01bdc27e2..25edcfc9ba5b 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -24,6 +24,7 @@ #include <asm/processor.h> #include <asm/ucontext.h> #include <asm/i387.h> +#include <asm/fpu-internal.h> #include <asm/vdso.h> #include <asm/mce.h> diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 4bbe04d96744..ec61d4c1b93b 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -54,6 +54,7 @@ #include <asm/traps.h> #include <asm/desc.h> #include <asm/i387.h> +#include <asm/fpu-internal.h> #include <asm/mce.h> #include <asm/mach_traps.h> diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c index 711091114119..e62728e30b01 100644 --- a/arch/x86/kernel/xsave.c +++ b/arch/x86/kernel/xsave.c @@ -6,6 +6,7 @@ #include <linux/bootmem.h> #include <linux/compat.h> #include <asm/i387.h> +#include <asm/fpu-internal.h> #ifdef CONFIG_IA32_EMULATION #include <asm/sigcontext32.h> #endif diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 3b4c8d8ad906..246490f643b6 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1457,7 +1457,7 @@ static void __vmx_load_host_state(struct vcpu_vmx *vmx) #ifdef CONFIG_X86_64 wrmsrl(MSR_KERNEL_GS_BASE, vmx->msr_host_kernel_gs_base); #endif - if (__thread_has_fpu(current)) + if (user_has_fpu()) clts(); load_gdt(&__get_cpu_var(host_gdt)); } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index bb4fd2636bc2..54696b5f8443 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -57,6 +57,7 @@ #include <asm/mtrr.h> #include <asm/mce.h> #include <asm/i387.h> +#include <asm/fpu-internal.h> /* Ugh! */ #include <asm/xcr.h> #include <asm/pvclock.h> #include <asm/div64.h> diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c index f10c0afa1cb4..4889655ba784 100644 --- a/arch/x86/power/cpu.c +++ b/arch/x86/power/cpu.c @@ -20,6 +20,7 @@ #include <asm/xcr.h> #include <asm/suspend.h> #include <asm/debugreg.h> +#include <asm/fpu-internal.h> /* pcntxt_mask */ #ifdef CONFIG_X86_32 static struct saved_context saved_context; |