diff options
Diffstat (limited to 'include/asm-i386/i387.h')
| -rw-r--r-- | include/asm-i386/i387.h | 26 |
1 files changed, 18 insertions, 8 deletions
diff --git a/include/asm-i386/i387.h b/include/asm-i386/i387.h index f6feb98a9397..6747006743f9 100644 --- a/include/asm-i386/i387.h +++ b/include/asm-i386/i387.h @@ -19,10 +19,21 @@ extern void mxcsr_feature_mask_init(void); extern void init_fpu(struct task_struct *); + /* * FPU lazy state save handling... */ -extern void restore_fpu( struct task_struct *tsk ); + +/* + * The "nop" is needed to make the instructions the same + * length. + */ +#define restore_fpu(tsk) \ + alternative_input( \ + "nop ; frstor %1", \ + "fxrstor %1", \ + X86_FEATURE_FXSR, \ + "m" ((tsk)->thread.i387.fxsave)) extern void kernel_fpu_begin(void); #define kernel_fpu_end() do { stts(); preempt_enable(); } while(0) @@ -32,13 +43,12 @@ extern void kernel_fpu_begin(void); */ static inline void __save_init_fpu( struct task_struct *tsk ) { - if ( cpu_has_fxsr ) { - asm volatile( "fxsave %0 ; fnclex" - : "=m" (tsk->thread.i387.fxsave) ); - } else { - asm volatile( "fnsave %0 ; fwait" - : "=m" (tsk->thread.i387.fsave) ); - } + alternative_input( + "fnsave %1 ; fwait ;" GENERIC_NOP2, + "fxsave %1 ; fnclex", + X86_FEATURE_FXSR, + "m" (tsk->thread.i387.fxsave) + :"memory"); tsk->thread_info->status &= ~TS_USEDFPU; } |