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/machine.h> 9 #include <asm/elf.h> 10 11 enum { 12 TYPE_HWCAP, 13 TYPE_FACILITY, 14 TYPE_MACHINE, 15 }; 16 17 struct s390_cpu_feature { 18 unsigned int type : 4; 19 unsigned int num : 28; 20 }; 21 22 static struct s390_cpu_feature s390_cpu_features[MAX_CPU_FEATURES] = { 23 [S390_CPU_FEATURE_MSA] = {.type = TYPE_HWCAP, .num = HWCAP_NR_MSA}, 24 [S390_CPU_FEATURE_VXRS] = {.type = TYPE_HWCAP, .num = HWCAP_NR_VXRS}, 25 [S390_CPU_FEATURE_UV] = {.type = TYPE_FACILITY, .num = 158}, 26 [S390_CPU_FEATURE_D288] = {.type = TYPE_MACHINE, .num = MFEATURE_DIAG288}, 27 }; 28 29 /* 30 * cpu_have_feature - Test CPU features on module initialization 31 */ 32 int cpu_have_feature(unsigned int num) 33 { 34 struct s390_cpu_feature *feature; 35 36 if (WARN_ON_ONCE(num >= MAX_CPU_FEATURES)) 37 return 0; 38 feature = &s390_cpu_features[num]; 39 switch (feature->type) { 40 case TYPE_HWCAP: 41 return !!(elf_hwcap & BIT(feature->num)); 42 case TYPE_FACILITY: 43 return test_facility(feature->num); 44 case TYPE_MACHINE: 45 return test_machine_feature(feature->num); 46 default: 47 WARN_ON_ONCE(1); 48 return 0; 49 } 50 } 51 EXPORT_SYMBOL(cpu_have_feature); 52