linux-kernel - [tip:x86/fpu] x86-64, asm: Use fxsaveq/fxrestorq in more places

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Message-ID: <tip-fd35fbcdd1b2579a6e00a1545f7124e4005d0474@git.kernel.org>
Date:	Sat, 23 Oct 2010 01:20:23 GMT
From:	"tip-bot for H. Peter Anvin" <hpa@...or.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org, hpa@...or.com, mingo@...hat.com,
	torvalds@...ux-foundation.org, tglx@...utronix.de
Subject: [tip:x86/fpu] x86-64, asm: Use fxsaveq/fxrestorq in more places

Commit-ID:  fd35fbcdd1b2579a6e00a1545f7124e4005d0474
Gitweb:     http://git.kernel.org/tip/fd35fbcdd1b2579a6e00a1545f7124e4005d0474
Author:     H. Peter Anvin <hpa@...or.com>
AuthorDate: Fri, 22 Oct 2010 15:33:38 -0700
Committer:  H. Peter Anvin <hpa@...or.com>
CommitDate: Fri, 22 Oct 2010 15:33:38 -0700

x86-64, asm: Use fxsaveq/fxrestorq in more places

Checkin d7acb92fea932ad2e7846480aeacddc2c03c8485 made use of fxsaveq
in fpu_fxsave() if the assembler supports it; this adds
fxsaveq/fxrstorq to fxrstor_checking() and fxsave_user() as well.

Reported-by: Linus Torvalds <torvalds@...ux-foundation.org>
LKML-Reference: <AANLkTi=RKyHLNTq6iomZOXkc6Zw1j9iAgsq8388XmzwN@...l.gmail.com>
Signed-off-by: H. Peter Anvin <hpa@...or.com>
---
 arch/x86/include/asm/i387.h |   24 ++++++++++++++++++++++++
 1 files changed, 24 insertions(+), 0 deletions(-)

diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index 4aa2bb3..ef32890 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -93,6 +93,17 @@ static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
 	int err;
 
 	/* See comment in fxsave() below. */
+#ifdef CONFIG_AS_FXSAVEQ
+	asm volatile("1:  fxrstorq %[fx]\n\t"
+		     "2:\n"
+		     ".section .fixup,\"ax\"\n"
+		     "3:  movl $-1,%[err]\n"
+		     "    jmp  2b\n"
+		     ".previous\n"
+		     _ASM_EXTABLE(1b, 3b)
+		     : [err] "=r" (err)
+		     : [fx] "m" (*fx), "0" (0));
+#else
 	asm volatile("1:  rex64/fxrstor (%[fx])\n\t"
 		     "2:\n"
 		     ".section .fixup,\"ax\"\n"
@@ -102,6 +113,7 @@ static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
 		     _ASM_EXTABLE(1b, 3b)
 		     : [err] "=r" (err)
 		     : [fx] "R" (fx), "m" (*fx), "0" (0));
+#endif
 	return err;
 }
 
@@ -119,6 +131,17 @@ static inline int fxsave_user(struct i387_fxsave_struct __user *fx)
 		return -EFAULT;
 
 	/* See comment in fxsave() below. */
+#ifdef CONFIG_AS_FXSAVEQ
+	asm volatile("1:  fxsaveq %[fx]\n\t"
+		     "2:\n"
+		     ".section .fixup,\"ax\"\n"
+		     "3:  movl $-1,%[err]\n"
+		     "    jmp  2b\n"
+		     ".previous\n"
+		     _ASM_EXTABLE(1b, 3b)
+		     : [err] "=r" (err), [fx] "=m" (*fx)
+		     : "0" (0));
+#else
 	asm volatile("1:  rex64/fxsave (%[fx])\n\t"
 		     "2:\n"
 		     ".section .fixup,\"ax\"\n"
@@ -128,6 +151,7 @@ static inline int fxsave_user(struct i387_fxsave_struct __user *fx)
 		     _ASM_EXTABLE(1b, 3b)
 		     : [err] "=r" (err), "=m" (*fx)
 		     : [fx] "R" (fx), "0" (0));
+#endif
 	if (unlikely(err) &&
 	    __clear_user(fx, sizeof(struct i387_fxsave_struct)))
 		err = -EFAULT;
--
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