x86/xsaves: Save xstate to task's xsave area in __save_fpu during booting time

Fenghua Yu · H. Peter Anvin · commit f41d830fa890 · 2014-05-29T14:33:04.000-07:00
__save_fpu() can be called during early booting time when cpu caps are not enabled and alternative can not be used yet. Therefore, it calls xsave_state_booting() during booting time to save xstate to task's xsave area. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Link: http://lkml.kernel.org/r/1401387164-43416-14-git-send-email-fenghua.yu@intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h
@@ -508,9 +508,12 @@ static inline void user_fpu_begin(void)
 
 static inline void __save_fpu(struct task_struct *tsk)
 {
-	if (use_xsave())
-		xsave_state(&tsk->thread.fpu.state->xsave, -1);
-	else
+	if (use_xsave()) {
+		if (unlikely(system_state == SYSTEM_BOOTING))
+			xsave_state_booting(&tsk->thread.fpu.state->xsave, -1);
+		else
+			xsave_state(&tsk->thread.fpu.state->xsave, -1);
+	} else
 		fpu_fxsave(&tsk->thread.fpu);
 }
 

Original file line number	Diff line number	Diff line change
`@@ -508,9 +508,12 @@ static inline void user_fpu_begin(void)`
`508`	`508`
`509`	`509`	`static inline void __save_fpu(struct task_struct *tsk)`
`510`	`510`	`{`
`511`		`- if (use_xsave())`
`512`		`- xsave_state(&tsk->thread.fpu.state->xsave, -1);`
`513`		`- else`
	`511`	`+ if (use_xsave()) {`
	`512`	`+ if (unlikely(system_state == SYSTEM_BOOTING))`
	`513`	`+ xsave_state_booting(&tsk->thread.fpu.state->xsave, -1);`
	`514`	`+ else`
	`515`	`+ xsave_state(&tsk->thread.fpu.state->xsave, -1);`
	`516`	`+ } else`
`514`	`517`	`fpu_fxsave(&tsk->thread.fpu);`
`515`	`518`	`}`
`516`	`519`