projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 359b7064 MZ |
1 | /* |
| 2 | * Contains CPU feature definitions | |
| 3 | * | |
| 4 | * Copyright (C) 2015 ARM Ltd. | |
| 5 | * | |
| 6 | * This program is free software; you can redistribute it and/or modify | |
| 7 | * it under the terms of the GNU General Public License version 2 as | |
| 8 | * published by the Free Software Foundation. | |
| 9 | * | |
| 10 | * This program is distributed in the hope that it will be useful, | |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 13 | * GNU General Public License for more details. | |
| 14 | * | |
| 15 | * You should have received a copy of the GNU General Public License | |
| 16 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
| 17 | */ | |
| 18 | ||
| 19 | #define pr_fmt(fmt) "alternatives: " fmt | |
| 20 | ||
| 21 | #include <linux/types.h> | |
| 22 | #include <asm/cpu.h> | |
| 23 | #include <asm/cpufeature.h> | |
| 338d4f49 | 24 | #include <asm/processor.h> |
| 359b7064 | 25 | |
| 18ffa046 JM |
26 | static bool |
| 27 | feature_matches(u64 reg, const struct arm64_cpu_capabilities *entry) | |
| 28 | { | |
| 29 | int val = cpuid_feature_extract_field(reg, entry->field_pos); | |
| 30 | ||
| 31 | return val >= entry->min_field_value; | |
| 32 | } | |
| 33 | ||
| 94a9e04a MZ |
34 | static bool |
| 35 | has_id_aa64pfr0_feature(const struct arm64_cpu_capabilities *entry) | |
| 36 | { | |
| 37 | u64 val; | |
| 38 | ||
| 39 | val = read_cpuid(id_aa64pfr0_el1); | |
| 18ffa046 | 40 | return feature_matches(val, entry); |
| 94a9e04a MZ |
41 | } |
| 42 | ||
| 338d4f49 JM |
43 | static bool __maybe_unused |
| 44 | has_id_aa64mmfr1_feature(const struct arm64_cpu_capabilities *entry) | |
| 45 | { | |
| 46 | u64 val; | |
| 47 | ||
| 48 | val = read_cpuid(id_aa64mmfr1_el1); | |
| 49 | return feature_matches(val, entry); | |
| 50 | } | |
| 51 | ||
| 359b7064 | 52 | static const struct arm64_cpu_capabilities arm64_features[] = { |
| 94a9e04a MZ |
53 | { |
| 54 | .desc = "GIC system register CPU interface", | |
| 55 | .capability = ARM64_HAS_SYSREG_GIC_CPUIF, | |
| 56 | .matches = has_id_aa64pfr0_feature, | |
| 18ffa046 JM |
57 | .field_pos = 24, |
| 58 | .min_field_value = 1, | |
| 94a9e04a | 59 | }, |
| 338d4f49 JM |
60 | #ifdef CONFIG_ARM64_PAN |
| 61 | { | |
| 62 | .desc = "Privileged Access Never", | |
| 63 | .capability = ARM64_HAS_PAN, | |
| 64 | .matches = has_id_aa64mmfr1_feature, | |
| 65 | .field_pos = 20, | |
| 66 | .min_field_value = 1, | |
| 67 | .enable = cpu_enable_pan, | |
| 68 | }, | |
| 69 | #endif /* CONFIG_ARM64_PAN */ | |
| 359b7064 MZ |
70 | {}, |
| 71 | }; | |
| 72 | ||
| 73 | void check_cpu_capabilities(const struct arm64_cpu_capabilities *caps, | |
| 74 | const char *info) | |
| 75 | { | |
| 76 | int i; | |
| 77 | ||
| 78 | for (i = 0; caps[i].desc; i++) { | |
| 79 | if (!caps[i].matches(&caps[i])) | |
| 80 | continue; | |
| 81 | ||
| 82 | if (!cpus_have_cap(caps[i].capability)) | |
| 83 | pr_info("%s %s\n", info, caps[i].desc); | |
| 84 | cpus_set_cap(caps[i].capability); | |
| 85 | } | |
| 1c076303 JM |
86 | |
| 87 | /* second pass allows enable() to consider interacting capabilities */ | |
| 88 | for (i = 0; caps[i].desc; i++) { | |
| 89 | if (cpus_have_cap(caps[i].capability) && caps[i].enable) | |
| 90 | caps[i].enable(); | |
| 91 | } | |
| 359b7064 MZ |
92 | } |
| 93 | ||
| 94 | void check_local_cpu_features(void) | |
| 95 | { | |
| 96 | check_cpu_capabilities(arm64_features, "detected feature"); | |
| 97 | } |