x86/xsaves: Use xsaves/xrstors for context switch
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>
diff --git a/arch/x86/include/asm/xsave.h b/arch/x86/include/asm/xsave.h
index f9177a2..8b75824 100644
--- a/arch/x86/include/asm/xsave.h
+++ b/arch/x86/include/asm/xsave.h
@@ -129,22 +129,20 @@
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 @@
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