[patch 6/9] x86, xsave: xsave/xrstor specific routines

[Suresh Siddha]

Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
---

Index: tip-0728/include/asm-x86/xsave.h
===================================================================
--- tip-0728.orig/include/asm-x86/xsave.h	2008-07-28 18:19:58.000000000 -0700
+++ tip-0728/include/asm-x86/xsave.h	2008-07-28 18:20:05.000000000 -0700
@@ -48,6 +48,58 @@
 	return err;
 }
 
+static inline int xsave_check(struct xsave_struct __user *buf)
+{
+	int err;
+	__asm__ __volatile__("1: .byte " REX_PREFIX "0x0f,0xae,0x27\n"
+			     "2:\n"
+			     ".section .fixup,\"ax\"\n"
+			     "3:  movl $-1,%[err]\n"
+			     "    jmp  2b\n"
+			     ".previous\n"
+			     ".section __ex_table,\"a\"\n"
+			     _ASM_ALIGN "\n"
+			     _ASM_PTR "1b,3b\n"
+			     ".previous"
+			     : [err] "=r" (err)
+			     : "D" (buf), "a" (-1), "d" (-1), "0" (0)
+			     : "memory");
+	if (unlikely(err) && __clear_user(buf, xstate_size))
+		err = -EFAULT;
+	/* No need to clear here because the caller clears USED_MATH */
+	return err;
+}
+
+static inline int xrestore_user(struct xsave_struct __user *buf,
+				unsigned int lmask,
+				unsigned int hmask)
+{
+	int err;
+	struct xsave_struct *xstate = ((__force struct xsave_struct *)buf);
+
+	__asm__ __volatile__("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n"
+			     "2:\n"
+			     ".section .fixup,\"ax\"\n"
+			     "3:  movl $-1,%[err]\n"
+			     "    jmp  2b\n"
+			     ".previous\n"
+			     ".section __ex_table,\"a\"\n"
+			     _ASM_ALIGN "\n"
+			     _ASM_PTR "1b,3b\n"
+			     ".previous"
+			     : [err] "=r" (err)
+			     : "D" (xstate), "a" (lmask), "d" (hmask), "0" (0)
+			     : "memory");	//memory required?
+	return err;
+}
+
+static inline void xrstor_state(struct xsave_struct *fx, int lmask, int hmask)
+{
+	asm volatile(".byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
+		     :: "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
+		     : "memory");
+}
+
 static inline void xsave(struct task_struct *tsk)
 {
 	/* This, however, we can work around by forcing the compiler to select

-- 

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