x86: use alternative instructions for fnsave/fxsave too
This one ends up using an inline asm format that claims to read memory
and then clobber it (rather than just write it directly), which made it
easier to use the existing "alternative_input()" infrastructure support.
Now the fxsave code matches the fxrstor.
diff --git a/include/asm-i386/i387.h b/include/asm-i386/i387.h
index e678609..6747006 100644
--- a/include/asm-i386/i387.h
+++ b/include/asm-i386/i387.h
@@ -33,7 +33,7 @@
"nop ; frstor %1", \
"fxrstor %1", \
X86_FEATURE_FXSR, \
- "m" ((tsk)->thread.i387.fsave))
+ "m" ((tsk)->thread.i387.fxsave))
extern void kernel_fpu_begin(void);
#define kernel_fpu_end() do { stts(); preempt_enable(); } while(0)
@@ -43,13 +43,12 @@
*/
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;
}