diff options
Diffstat (limited to 'arch/x86/include/asm')
| -rw-r--r-- | arch/x86/include/asm/cpufeature.h | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/fpu-internal.h | 54 |
2 files changed, 41 insertions, 15 deletions
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index 6b7ee5ff6820..5dd2b473ccff 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -97,6 +97,7 @@ #define X86_FEATURE_EXTD_APICID (3*32+26) /* has extended APICID (8 bits) */ #define X86_FEATURE_AMD_DCM (3*32+27) /* multi-node processor */ #define X86_FEATURE_APERFMPERF (3*32+28) /* APERFMPERF */ +#define X86_FEATURE_EAGER_FPU (3*32+29) /* "eagerfpu" Non lazy FPU restore */ /* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */ #define X86_FEATURE_XMM3 (4*32+ 0) /* "pni" SSE-3 */ @@ -305,6 +306,7 @@ extern const char * const x86_power_flags[32]; #define cpu_has_perfctr_core boot_cpu_has(X86_FEATURE_PERFCTR_CORE) #define cpu_has_cx8 boot_cpu_has(X86_FEATURE_CX8) #define cpu_has_cx16 boot_cpu_has(X86_FEATURE_CX16) +#define cpu_has_eager_fpu boot_cpu_has(X86_FEATURE_EAGER_FPU) #if defined(CONFIG_X86_INVLPG) || defined(CONFIG_X86_64) # define cpu_has_invlpg 1 diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h index 8ca0f9f45ac4..0ca72f0d4b41 100644 --- a/arch/x86/include/asm/fpu-internal.h +++ b/arch/x86/include/asm/fpu-internal.h @@ -38,6 +38,7 @@ int ia32_setup_frame(int sig, struct k_sigaction *ka, extern unsigned int mxcsr_feature_mask; extern void fpu_init(void); +extern void eager_fpu_init(void); DECLARE_PER_CPU(struct task_struct *, fpu_owner_task); @@ -84,6 +85,11 @@ static inline int is_x32_frame(void) #define X87_FSW_ES (1 << 7) /* Exception Summary */ +static __always_inline __pure bool use_eager_fpu(void) +{ + return static_cpu_has(X86_FEATURE_EAGER_FPU); +} + static __always_inline __pure bool use_xsaveopt(void) { return static_cpu_has(X86_FEATURE_XSAVEOPT); @@ -99,6 +105,14 @@ static __always_inline __pure bool use_fxsr(void) return static_cpu_has(X86_FEATURE_FXSR); } +static inline void fx_finit(struct i387_fxsave_struct *fx) +{ + memset(fx, 0, xstate_size); + fx->cwd = 0x37f; + if (cpu_has_xmm) + fx->mxcsr = MXCSR_DEFAULT; +} + extern void __sanitize_i387_state(struct task_struct *); static inline void sanitize_i387_state(struct task_struct *tsk) @@ -291,13 +305,13 @@ static inline void __thread_set_has_fpu(struct task_struct *tsk) static inline void __thread_fpu_end(struct task_struct *tsk) { __thread_clear_has_fpu(tsk); - if (!use_xsave()) + if (!use_eager_fpu()) stts(); } static inline void __thread_fpu_begin(struct task_struct *tsk) { - if (!use_xsave()) + if (!use_eager_fpu()) clts(); __thread_set_has_fpu(tsk); } @@ -327,10 +341,14 @@ static inline void drop_fpu(struct task_struct *tsk) static inline void drop_init_fpu(struct task_struct *tsk) { - if (!use_xsave()) + if (!use_eager_fpu()) drop_fpu(tsk); - else - xrstor_state(init_xstate_buf, -1); + else { + if (use_xsave()) + xrstor_state(init_xstate_buf, -1); + else + fxrstor_checking(&init_xstate_buf->i387); + } } /* @@ -370,7 +388,7 @@ static inline fpu_switch_t switch_fpu_prepare(struct task_struct *old, struct ta * If the task has used the math, pre-load the FPU on xsave processors * or if the past 5 consecutive context-switches used math. */ - fpu.preload = tsk_used_math(new) && (use_xsave() || + fpu.preload = tsk_used_math(new) && (use_eager_fpu() || new->fpu_counter > 5); if (__thread_has_fpu(old)) { if (!__save_init_fpu(old)) @@ -383,14 +401,14 @@ static inline fpu_switch_t switch_fpu_prepare(struct task_struct *old, struct ta new->fpu_counter++; __thread_set_has_fpu(new); prefetch(new->thread.fpu.state); - } else if (!use_xsave()) + } else if (!use_eager_fpu()) stts(); } else { old->fpu_counter = 0; old->thread.fpu.last_cpu = ~0; if (fpu.preload) { new->fpu_counter++; - if (!use_xsave() && fpu_lazy_restore(new, cpu)) + if (!use_eager_fpu() && fpu_lazy_restore(new, cpu)) fpu.preload = 0; else prefetch(new->thread.fpu.state); @@ -452,6 +470,14 @@ static inline void user_fpu_begin(void) preempt_enable(); } +static inline void __save_fpu(struct task_struct *tsk) +{ + if (use_xsave()) + xsave_state(&tsk->thread.fpu.state->xsave, -1); + else + fpu_fxsave(&tsk->thread.fpu); +} + /* * These disable preemption on their own and are safe */ @@ -459,8 +485,8 @@ static inline void save_init_fpu(struct task_struct *tsk) { WARN_ON_ONCE(!__thread_has_fpu(tsk)); - if (use_xsave()) { - xsave_state(&tsk->thread.fpu.state->xsave, -1); + if (use_eager_fpu()) { + __save_fpu(tsk); return; } @@ -526,11 +552,9 @@ static inline void fpu_free(struct fpu *fpu) static inline void fpu_copy(struct task_struct *dst, struct task_struct *src) { - if (use_xsave()) { - struct xsave_struct *xsave = &dst->thread.fpu.state->xsave; - - memset(&xsave->xsave_hdr, 0, sizeof(struct xsave_hdr_struct)); - xsave_state(xsave, -1); + if (use_eager_fpu()) { + memset(&dst->thread.fpu.state->xsave, 0, xstate_size); + __save_fpu(dst); } else { struct fpu *dfpu = &dst->thread.fpu; struct fpu *sfpu = &src->thread.fpu; |