LXR linux/arch/s390/include/asm/cpufeature.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 * Module interface for CPU features
   4 *
   5 * Copyright IBM Corp. 2015
   6 * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
   7 */
   8
   9#ifndef __ASM_S390_CPUFEATURE_H
  10#define __ASM_S390_CPUFEATURE_H
  11
  12#include <asm/elf.h>
  13
  14/* Hardware features on Linux on z Systems are indicated by facility bits that
  15 * are mapped to the so-called machine flags.  Particular machine flags are
  16 * then used to define ELF hardware capabilities; most notably hardware flags
  17 * that are essential for user space / glibc.
  18 *
  19 * Restrict the set of exposed CPU features to ELF hardware capabilities for
  20 * now.  Additional machine flags can be indicated by values larger than
  21 * MAX_ELF_HWCAP_FEATURES.
  22 */
  23#define MAX_ELF_HWCAP_FEATURES  (8 * sizeof(elf_hwcap))
  24#define MAX_CPU_FEATURES        MAX_ELF_HWCAP_FEATURES
  25
  26#define cpu_feature(feat)       ilog2(HWCAP_S390_ ## feat)
  27
  28int cpu_have_feature(unsigned int nr);
  29
  30#endif /* __ASM_S390_CPUFEATURE_H */
  31