| 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 | [S390_CPU_FEATURE_UV] = {.type = TYPE_FACILITY, .num = 158}, |
| 24 | }; |
| 25 | |
| 26 | /* |
| 27 | * cpu_have_feature - Test CPU features on module initialization |
| 28 | */ |
| 29 | int cpu_have_feature(unsigned int num) |
| 30 | { |
| 31 | struct s390_cpu_feature *feature; |
| 32 | |
| 33 | if (WARN_ON_ONCE(num >= MAX_CPU_FEATURES)) |
| 34 | return 0; |
| 35 | feature = &s390_cpu_features[num]; |
| 36 | switch (feature->type) { |
| 37 | case TYPE_HWCAP: |
| 38 | return !!(elf_hwcap & BIT(feature->num)); |
| 39 | case TYPE_FACILITY: |
| 40 | return test_facility(feature->num); |
| 41 | default: |
| 42 | WARN_ON_ONCE(1); |
| 43 | return 0; |
| 44 | } |
| 45 | } |
| 46 | EXPORT_SYMBOL(cpu_have_feature); |
| 47 |