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x86/xsaves: Use xsaves/xrstors for context switch

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If xsaves is eanbled, use xsaves/xrstors for context switch to support
compacted format xsave area to occupy less memory and modified optimization
to improve saving performance.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1401387164-43416-10-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This commit is contained in:
Fenghua Yu 2014-05-29 11:12:37 -07:00 committed by H. Peter Anvin
parent f31a9f7c71
commit f9de314b34
1 changed files with 12 additions and 25 deletions
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37
arch/x86/include/asm/xsave.h
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@ -129,22 +129,20 @@ static inline int xrstor_state(struct xsave_struct *fx, u64 mask)
return err;
}
/*
* Save xstate context for old process during context switch.
*/
static inline void fpu_xsave(struct fpu *fpu)
{
xsave_state(&fpu->state->xsave, -1);
}
/*
* Restore xstate context for new process during context switch.
*/
static inline int fpu_xrstor_checking(struct xsave_struct *fx)
{
int err;
asm volatile("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\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)
: "D" (fx), "m" (*fx), "a" (-1), "d" (-1), "0" (0)
: "memory");
return err;
return xrstor_state(fx, -1);
}
static inline int xsave_user(struct xsave_struct __user *buf)
@ -194,15 +192,4 @@ static inline int xrestore_user(struct xsave_struct __user *buf, u64 mask)
return err;
}
static inline void fpu_xsave(struct fpu *fpu)
{
/* This, however, we can work around by forcing the compiler to select
an addressing mode that doesn't require extended registers. */
alternative_input(
".byte " REX_PREFIX "0x0f,0xae,0x27",
".byte " REX_PREFIX "0x0f,0xae,0x37",
X86_FEATURE_XSAVEOPT,
[fx] "D" (&fpu->state->xsave), "a" (-1), "d" (-1) :
"memory");
}
#endif