LXR linux/arch/x86/include/asm/xcr.h

   1/* -*- linux-c -*- ------------------------------------------------------- *
   2 *
   3 *   Copyright 2008 rPath, Inc. - All Rights Reserved
   4 *
   5 *   This file is part of the Linux kernel, and is made available under
   6 *   the terms of the GNU General Public License version 2 or (at your
   7 *   option) any later version; incorporated herein by reference.
   8 *
   9 * ----------------------------------------------------------------------- */
  10
  11/*
  12 * asm-x86/xcr.h
  13 *
  14 * Definitions for the eXtended Control Register instructions
  15 */
  16
  17#ifndef _ASM_X86_XCR_H
  18#define _ASM_X86_XCR_H
  19
  20#define XCR_XFEATURE_ENABLED_MASK       0x00000000
  21
  22#ifdef __KERNEL__
  23# ifndef __ASSEMBLY__
  24
  25#include <linux/types.h>
  26
  27static inline u64 xgetbv(u32 index)
  28{
  29        u32 eax, edx;
  30
  31        asm volatile(".byte 0x0f,0x01,0xd0" /* xgetbv */
  32                     : "=a" (eax), "=d" (edx)
  33                     : "c" (index));
  34        return eax + ((u64)edx << 32);
  35}
  36
  37static inline void xsetbv(u32 index, u64 value)
  38{
  39        u32 eax = value;
  40        u32 edx = value >> 32;
  41
  42        asm volatile(".byte 0x0f,0x01,0xd1" /* xsetbv */
  43                     : : "a" (eax), "d" (edx), "c" (index));
  44}
  45
  46# endif /* __ASSEMBLY__ */
  47#endif /* __KERNEL__ */
  48
  49#endif /* _ASM_X86_XCR_H */
  50