1 /* 2 * Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org> 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 */ 8 9 #ifndef __ASM_CPUFEATURE_H 10 #define __ASM_CPUFEATURE_H 11 12 #include <asm/hwcap.h> 13 #include <asm/sysreg.h> 14 15 /* 16 * In the arm64 world (as in the ARM world), elf_hwcap is used both internally 17 * in the kernel and for user space to keep track of which optional features 18 * are supported by the current system. So let's map feature 'x' to HWCAP_x. 19 * Note that HWCAP_x constants are bit fields so we need to take the log. 20 */ 21 22 #define MAX_CPU_FEATURES (8 * sizeof(elf_hwcap)) 23 #define cpu_feature(x) ilog2(HWCAP_ ## x) 24 25 #define ARM64_WORKAROUND_CLEAN_CACHE 0 26 #define ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE 1 27 #define ARM64_WORKAROUND_845719 2 28 #define ARM64_HAS_SYSREG_GIC_CPUIF 3 29 #define ARM64_HAS_PAN 4 30 #define ARM64_HAS_LSE_ATOMICS 5 31 #define ARM64_WORKAROUND_CAVIUM_23154 6 32 33 #define ARM64_NCAPS 7 34 35 #ifndef __ASSEMBLY__ 36 37 #include <linux/kernel.h> 38 39 /* CPU feature register tracking */ 40 enum ftr_type { 41 FTR_EXACT, /* Use a predefined safe value */ 42 FTR_LOWER_SAFE, /* Smaller value is safe */ 43 FTR_HIGHER_SAFE,/* Bigger value is safe */ 44 }; 45 46 #define FTR_STRICT true /* SANITY check strict matching required */ 47 #define FTR_NONSTRICT false /* SANITY check ignored */ 48 49 struct arm64_ftr_bits { 50 bool strict; /* CPU Sanity check: strict matching required ? */ 51 enum ftr_type type; 52 u8 shift; 53 u8 width; 54 s64 safe_val; /* safe value for discrete features */ 55 }; 56 57 /* 58 * @arm64_ftr_reg - Feature register 59 * @strict_mask Bits which should match across all CPUs for sanity. 60 * @sys_val Safe value across the CPUs (system view) 61 */ 62 struct arm64_ftr_reg { 63 u32 sys_id; 64 const char *name; 65 u64 strict_mask; 66 u64 sys_val; 67 struct arm64_ftr_bits *ftr_bits; 68 }; 69 70 struct arm64_cpu_capabilities { 71 const char *desc; 72 u16 capability; 73 bool (*matches)(const struct arm64_cpu_capabilities *); 74 void (*enable)(void *); /* Called on all active CPUs */ 75 union { 76 struct { /* To be used for erratum handling only */ 77 u32 midr_model; 78 u32 midr_range_min, midr_range_max; 79 }; 80 81 struct { /* Feature register checking */ 82 u32 sys_reg; 83 int field_pos; 84 int min_field_value; 85 int hwcap_type; 86 unsigned long hwcap; 87 }; 88 }; 89 }; 90 91 extern DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS); 92 93 static inline bool cpu_have_feature(unsigned int num) 94 { 95 return elf_hwcap & (1UL << num); 96 } 97 98 static inline bool cpus_have_cap(unsigned int num) 99 { 100 if (num >= ARM64_NCAPS) 101 return false; 102 return test_bit(num, cpu_hwcaps); 103 } 104 105 static inline void cpus_set_cap(unsigned int num) 106 { 107 if (num >= ARM64_NCAPS) 108 pr_warn("Attempt to set an illegal CPU capability (%d >= %d)\n", 109 num, ARM64_NCAPS); 110 else 111 __set_bit(num, cpu_hwcaps); 112 } 113 114 static inline int __attribute_const__ 115 cpuid_feature_extract_field_width(u64 features, int field, int width) 116 { 117 return (s64)(features << (64 - width - field)) >> (64 - width); 118 } 119 120 static inline int __attribute_const__ 121 cpuid_feature_extract_field(u64 features, int field) 122 { 123 return cpuid_feature_extract_field_width(features, field, 4); 124 } 125 126 static inline u64 arm64_ftr_mask(struct arm64_ftr_bits *ftrp) 127 { 128 return (u64)GENMASK(ftrp->shift + ftrp->width - 1, ftrp->shift); 129 } 130 131 static inline s64 arm64_ftr_value(struct arm64_ftr_bits *ftrp, u64 val) 132 { 133 return cpuid_feature_extract_field_width(val, ftrp->shift, ftrp->width); 134 } 135 136 static inline bool id_aa64mmfr0_mixed_endian_el0(u64 mmfr0) 137 { 138 return cpuid_feature_extract_field(mmfr0, ID_AA64MMFR0_BIGENDEL_SHIFT) == 0x1 || 139 cpuid_feature_extract_field(mmfr0, ID_AA64MMFR0_BIGENDEL0_SHIFT) == 0x1; 140 } 141 142 void __init setup_cpu_features(void); 143 144 void update_cpu_capabilities(const struct arm64_cpu_capabilities *caps, 145 const char *info); 146 void check_local_cpu_errata(void); 147 148 #ifdef CONFIG_HOTPLUG_CPU 149 void verify_local_cpu_capabilities(void); 150 #else 151 static inline void verify_local_cpu_capabilities(void) 152 { 153 } 154 #endif 155 156 u64 read_system_reg(u32 id); 157 158 static inline bool cpu_supports_mixed_endian_el0(void) 159 { 160 return id_aa64mmfr0_mixed_endian_el0(read_cpuid(ID_AA64MMFR0_EL1)); 161 } 162 163 static inline bool system_supports_mixed_endian_el0(void) 164 { 165 return id_aa64mmfr0_mixed_endian_el0(read_system_reg(SYS_ID_AA64MMFR0_EL1)); 166 } 167 168 #endif /* __ASSEMBLY__ */ 169 170 #endif 171