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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@zytor.com>
AuthorDate: Fri, 22 Oct 2010 15:33:38 -0700
Committer: H. Peter Anvin <hpa@zytor.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@linux-foundation.org>
LKML-Reference: <AANLkTi=RKyHLNTq6iomZOXkc6Zw1j9iAgsq8388XmzwN@mail.gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.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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