arch/s390/include/asm/cpufeature.h

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