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 TYPE_FACILITY, 13 }; 14 15 struct s390_cpu_feature { 16 unsigned int type : 4; 17 unsigned int num : 28; 18 }; 19 20 static struct s390_cpu_feature s390_cpu_features[MAX_CPU_FEATURES] = { 21 [S390_CPU_FEATURE_MSA] = {.type = TYPE_HWCAP, .num = HWCAP_NR_MSA}, 22 [S390_CPU_FEATURE_VXRS] = {.type = TYPE_HWCAP, .num = HWCAP_NR_VXRS}, 23 }; 24 25 /* 26 * cpu_have_feature - Test CPU features on module initialization 27 */ 28 int cpu_have_feature(unsigned int num) 29 { 30 struct s390_cpu_feature *feature; 31 32 if (WARN_ON_ONCE(num >= MAX_CPU_FEATURES)) 33 return 0; 34 feature = &s390_cpu_features[num]; 35 switch (feature->type) { 36 case TYPE_HWCAP: 37 return !!(elf_hwcap & BIT(feature->num)); 38 case TYPE_FACILITY: 39 return test_facility(feature->num); 40 default: 41 WARN_ON_ONCE(1); 42 return 0; 43 } 44 } 45 EXPORT_SYMBOL(cpu_have_feature); 46