LXR linux/arch/arm64/include/asm/cpufeature.h

   1/*
   2 * Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org>
   3 *
   4 * This program is free software; you can redistribute it and/or modify
   5 * it under the terms of the GNU General Public License version 2 as
   6 * published by the Free Software Foundation.
   7 */
   8
   9#ifndef __ASM_CPUFEATURE_H
  10#define __ASM_CPUFEATURE_H
  11
  12#include <asm/hwcap.h>
  13
  14/*
  15 * In the arm64 world (as in the ARM world), elf_hwcap is used both internally
  16 * in the kernel and for user space to keep track of which optional features
  17 * are supported by the current system. So let's map feature 'x' to HWCAP_x.
  18 * Note that HWCAP_x constants are bit fields so we need to take the log.
  19 */
  20
  21#define MAX_CPU_FEATURES        (8 * sizeof(elf_hwcap))
  22#define cpu_feature(x)          ilog2(HWCAP_ ## x)
  23
  24static inline bool cpu_have_feature(unsigned int num)
  25{
  26        return elf_hwcap & (1UL << num);
  27}
  28
  29#endif
  30