x86, xsave: add <asm/xcr.h> header file for XCR registers

/* -*- linux-c -*- ------------------------------------------------------- *

 *

 *   Copyright 2008 rPath, Inc. - All Rights Reserved

 *

 *   This file is part of the Linux kernel, and is made available under

 *   the terms of the GNU General Public License version 2 or (at your

 *   option) any later version; incorporated herein by reference.

 *

 * ----------------------------------------------------------------------- */

/*

 * asm-x86/xcr.h

 *

 * Definitions for the eXtended Control Register instructions

 */

#ifndef _ASM_X86_XCR_H

#define _ASM_X86_XCR_H

#define XCR_XFEATURE_ENABLED_MASK	0x00000000

#ifdef __KERNEL__

# ifndef __ASSEMBLY__

#include <linux/types.h>

static inline u64 xgetbv(u32 index)

{

	u32 eax, edx;

	asm volatile(".byte 0x0f,0x01,0xd0" /* xgetbv */

		     : "=a" (eax), "=d" (edx)

		     : "c" (index));

	return eax + ((u64)edx << 32);

}

static inline void xsetbv(u32 index, u64 value)

{

	u32 eax = value;

	u32 edx = value >> 32;

	asm volatile(".byte 0x0f,0x01,0xd1" /* xsetbv */

		     : : "a" (eax), "d" (edx), "c" (index));

}

# endif /* __ASSEMBLY__ */

#endif /* __KERNEL__ */

#endif /* _ASM_X86_XCR_H */