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

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

[tip-bot for Fenghua Yu]

Commit-ID:  f41d830fa890044cb60f6bb39fc8f6493ffebb47
Gitweb:     http://git.kernel.org/tip/f41d830fa890044cb60f6bb39fc8f6493ffebb47
Author:     Fenghua Yu <fenghua.yu@intel.com>
AuthorDate: Thu, 29 May 2014 11:12:41 -0700
Committer:  H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Thu, 29 May 2014 14:33:04 -0700

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

__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>
---
 arch/x86/include/asm/fpu-internal.h | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h
index cea1c76..6099c0e 100644
--- 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);
 }