arch/arm64/include/asm/cpufeature.h

   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 #define ARM64_WORKAROUND_834220                 7
  33 #define ARM64_HAS_NO_HW_PREFETCH                8
  34 #define ARM64_HAS_UAO                           9
  35
  36 #define ARM64_NCAPS                             10
  37
  38 #ifndef __ASSEMBLY__
  39
  40 #include <linux/kernel.h>
  41
  42 /* CPU feature register tracking */
  43 enum ftr_type {
  44         FTR_EXACT,      /* Use a predefined safe value */
  45         FTR_LOWER_SAFE, /* Smaller value is safe */
  46         FTR_HIGHER_SAFE,/* Bigger value is safe */
  47 };
  48
  49 #define FTR_STRICT      true    /* SANITY check strict matching required */
  50 #define FTR_NONSTRICT   false   /* SANITY check ignored */
  51
  52 #define FTR_SIGNED      true    /* Value should be treated as signed */
  53 #define FTR_UNSIGNED    false   /* Value should be treated as unsigned */
  54
  55 struct arm64_ftr_bits {
  56         bool            sign;   /* Value is signed ? */
  57         bool            strict; /* CPU Sanity check: strict matching required ? */
  58         enum ftr_type   type;
  59         u8              shift;
  60         u8              width;
  61         s64             safe_val; /* safe value for discrete features */
  62 };
  63
  64 /*
  65  * @arm64_ftr_reg - Feature register
  66  * @strict_mask         Bits which should match across all CPUs for sanity.
  67  * @sys_val             Safe value across the CPUs (system view)
  68  */
  69 struct arm64_ftr_reg {
  70         u32                     sys_id;
  71         const char              *name;
  72         u64                     strict_mask;
  73         u64                     sys_val;
  74         struct arm64_ftr_bits   *ftr_bits;
  75 };
  76
  77 struct arm64_cpu_capabilities {
  78         const char *desc;
  79         u16 capability;
  80         bool (*matches)(const struct arm64_cpu_capabilities *);
  81         void (*enable)(void *);         /* Called on all active CPUs */
  82         union {
  83                 struct {        /* To be used for erratum handling only */
  84                         u32 midr_model;
  85                         u32 midr_range_min, midr_range_max;
  86                 };
  87
  88                 struct {        /* Feature register checking */
  89                         u32 sys_reg;
  90                         int field_pos;
  91                         int min_field_value;
  92                         int hwcap_type;
  93                         unsigned long hwcap;
  94                 };
  95         };
  96 };
  97
  98 extern DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS);
  99
 100 static inline bool cpu_have_feature(unsigned int num)
 101 {
 102         return elf_hwcap & (1UL << num);
 103 }
 104
 105 static inline bool cpus_have_cap(unsigned int num)
 106 {
 107         if (num >= ARM64_NCAPS)
 108                 return false;
 109         return test_bit(num, cpu_hwcaps);
 110 }
 111
 112 static inline void cpus_set_cap(unsigned int num)
 113 {
 114         if (num >= ARM64_NCAPS)
 115                 pr_warn("Attempt to set an illegal CPU capability (%d >= %d)\n",
 116                         num, ARM64_NCAPS);
 117         else
 118                 __set_bit(num, cpu_hwcaps);
 119 }
 120
 121 static inline int __attribute_const__
 122 cpuid_feature_extract_field_width(u64 features, int field, int width)
 123 {
 124         return (s64)(features << (64 - width - field)) >> (64 - width);
 125 }
 126
 127 static inline int __attribute_const__
 128 cpuid_feature_extract_field(u64 features, int field)
 129 {
 130         return cpuid_feature_extract_field_width(features, field, 4);
 131 }
 132
 133 static inline unsigned int __attribute_const__
 134 cpuid_feature_extract_unsigned_field_width(u64 features, int field, int width)
 135 {
 136         return (u64)(features << (64 - width - field)) >> (64 - width);
 137 }
 138
 139 static inline unsigned int __attribute_const__
 140 cpuid_feature_extract_unsigned_field(u64 features, int field)
 141 {
 142         return cpuid_feature_extract_unsigned_field_width(features, field, 4);
 143 }
 144
 145 static inline u64 arm64_ftr_mask(struct arm64_ftr_bits *ftrp)
 146 {
 147         return (u64)GENMASK(ftrp->shift + ftrp->width - 1, ftrp->shift);
 148 }
 149
 150 static inline s64 arm64_ftr_value(struct arm64_ftr_bits *ftrp, u64 val)
 151 {
 152         return ftrp->sign ?
 153                 cpuid_feature_extract_field_width(val, ftrp->shift, ftrp->width) :
 154                 cpuid_feature_extract_unsigned_field_width(val, ftrp->shift, ftrp->width);
 155 }
 156
 157 static inline bool id_aa64mmfr0_mixed_endian_el0(u64 mmfr0)
 158 {
 159         return cpuid_feature_extract_field(mmfr0, ID_AA64MMFR0_BIGENDEL_SHIFT) == 0x1 ||
 160                 cpuid_feature_extract_field(mmfr0, ID_AA64MMFR0_BIGENDEL0_SHIFT) == 0x1;
 161 }
 162
 163 void __init setup_cpu_features(void);
 164
 165 void update_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
 166                             const char *info);
 167 void check_local_cpu_errata(void);
 168
 169 #ifdef CONFIG_HOTPLUG_CPU
 170 void verify_local_cpu_capabilities(void);
 171 #else
 172 static inline void verify_local_cpu_capabilities(void)
 173 {
 174 }
 175 #endif
 176
 177 u64 read_system_reg(u32 id);
 178
 179 static inline bool cpu_supports_mixed_endian_el0(void)
 180 {
 181         return id_aa64mmfr0_mixed_endian_el0(read_cpuid(SYS_ID_AA64MMFR0_EL1));
 182 }
 183
 184 static inline bool system_supports_mixed_endian_el0(void)
 185 {
 186         return id_aa64mmfr0_mixed_endian_el0(read_system_reg(SYS_ID_AA64MMFR0_EL1));
 187 }
 188
 189 #endif /* __ASSEMBLY__ */
 190
 191 #endif