1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright IBM Corp. 2022 4 */ 5 6 #include <linux/cpufeature.h> 7 #include <linux/bug.h> 8 #include <asm/elf.h> 9 10 enum { 11 TYPE_HWCAP, 12 }; 13 14 struct s390_cpu_feature { 15 unsigned int type : 4; 16 unsigned int num : 28; 17 }; 18 19 static struct s390_cpu_feature s390_cpu_features[MAX_CPU_FEATURES] = { 20 [S390_CPU_FEATURE_MSA] = {.type = TYPE_HWCAP, .num = HWCAP_NR_MSA}, 21 [S390_CPU_FEATURE_VXRS] = {.type = TYPE_HWCAP, .num = HWCAP_NR_VXRS}, 22 }; 23 24 /* 25 * cpu_have_feature - Test CPU features on module initialization 26 */ 27 int cpu_have_feature(unsigned int num) 28 { 29 struct s390_cpu_feature *feature; 30 31 if (WARN_ON_ONCE(num >= MAX_CPU_FEATURES)) 32 return 0; 33 feature = &s390_cpu_features[num]; 34 switch (feature->type) { 35 case TYPE_HWCAP: 36 return !!(elf_hwcap & BIT(feature->num)); 37 default: 38 WARN_ON_ONCE(1); 39 return 0; 40 } 41 } 42 EXPORT_SYMBOL(cpu_have_feature); 43