arch/arm64/kernel/cpufeature.c

   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) "CPU features: " fmt
  20
  21 #include <linux/bsearch.h>
  22 #include <linux/cpumask.h>
  23 #include <linux/sort.h>
  24 #include <linux/stop_machine.h>
  25 #include <linux/types.h>
  26 #include <linux/mm.h>
  27 #include <asm/cpu.h>
  28 #include <asm/cpufeature.h>
  29 #include <asm/cpu_ops.h>
  30 #include <asm/fpsimd.h>
  31 #include <asm/mmu_context.h>
  32 #include <asm/processor.h>
  33 #include <asm/sysreg.h>
  34 #include <asm/traps.h>
  35 #include <asm/virt.h>
  36
  37 unsigned long elf_hwcap __read_mostly;
  38 EXPORT_SYMBOL_GPL(elf_hwcap);
  39
  40 #ifdef CONFIG_COMPAT
  41 #define COMPAT_ELF_HWCAP_DEFAULT        \
  42                                 (COMPAT_HWCAP_HALF|COMPAT_HWCAP_THUMB|\
  43                                  COMPAT_HWCAP_FAST_MULT|COMPAT_HWCAP_EDSP|\
  44                                  COMPAT_HWCAP_TLS|COMPAT_HWCAP_VFP|\
  45                                  COMPAT_HWCAP_VFPv3|COMPAT_HWCAP_VFPv4|\
  46                                  COMPAT_HWCAP_NEON|COMPAT_HWCAP_IDIV|\
  47                                  COMPAT_HWCAP_LPAE)
  48 unsigned int compat_elf_hwcap __read_mostly = COMPAT_ELF_HWCAP_DEFAULT;
  49 unsigned int compat_elf_hwcap2 __read_mostly;
  50 #endif
  51
  52 DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS);
  53 EXPORT_SYMBOL(cpu_hwcaps);
  54
  55 /*
  56  * Flag to indicate if we have computed the system wide
  57  * capabilities based on the boot time active CPUs. This
  58  * will be used to determine if a new booting CPU should
  59  * go through the verification process to make sure that it
  60  * supports the system capabilities, without using a hotplug
  61  * notifier.
  62  */
  63 static bool sys_caps_initialised;
  64
  65 static inline void set_sys_caps_initialised(void)
  66 {
  67         sys_caps_initialised = true;
  68 }
  69
  70 static int dump_cpu_hwcaps(struct notifier_block *self, unsigned long v, void *p)
  71 {
  72         /* file-wide pr_fmt adds "CPU features: " prefix */
  73         pr_emerg("0x%*pb\n", ARM64_NCAPS, &cpu_hwcaps);
  74         return 0;
  75 }
  76
  77 static struct notifier_block cpu_hwcaps_notifier = {
  78         .notifier_call = dump_cpu_hwcaps
  79 };
  80
  81 static int __init register_cpu_hwcaps_dumper(void)
  82 {
  83         atomic_notifier_chain_register(&panic_notifier_list,
  84                                        &cpu_hwcaps_notifier);
  85         return 0;
  86 }
  87 __initcall(register_cpu_hwcaps_dumper);
  88
  89 DEFINE_STATIC_KEY_ARRAY_FALSE(cpu_hwcap_keys, ARM64_NCAPS);
  90 EXPORT_SYMBOL(cpu_hwcap_keys);
  91
  92 #define __ARM64_FTR_BITS(SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
  93         {                                               \
  94                 .sign = SIGNED,                         \
  95                 .visible = VISIBLE,                     \
  96                 .strict = STRICT,                       \
  97                 .type = TYPE,                           \
  98                 .shift = SHIFT,                         \
  99                 .width = WIDTH,                         \
 100                 .safe_val = SAFE_VAL,                   \
 101         }
 102
 103 /* Define a feature with unsigned values */
 104 #define ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
 105         __ARM64_FTR_BITS(FTR_UNSIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL)
 106
 107 /* Define a feature with a signed value */
 108 #define S_ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
 109         __ARM64_FTR_BITS(FTR_SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL)
 110
 111 #define ARM64_FTR_END                                   \
 112         {                                               \
 113                 .width = 0,                             \
 114         }
 115
 116 /* meta feature for alternatives */
 117 static bool __maybe_unused
 118 cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry, int __unused);
 119
 120
 121 /*
 122  * NOTE: Any changes to the visibility of features should be kept in
 123  * sync with the documentation of the CPU feature register ABI.
 124  */
 125 static const struct arm64_ftr_bits ftr_id_aa64isar0[] = {
 126         ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_FHM_SHIFT, 4, 0),
 127         ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_DP_SHIFT, 4, 0),
 128         ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SM4_SHIFT, 4, 0),
 129         ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SM3_SHIFT, 4, 0),
 130         ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA3_SHIFT, 4, 0),
 131         ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_RDM_SHIFT, 4, 0),
 132         ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_ATOMICS_SHIFT, 4, 0),
 133         ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_CRC32_SHIFT, 4, 0),
 134         ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA2_SHIFT, 4, 0),
 135         ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA1_SHIFT, 4, 0),
 136         ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_AES_SHIFT, 4, 0),
 137         ARM64_FTR_END,
 138 };
 139
 140 static const struct arm64_ftr_bits ftr_id_aa64isar1[] = {
 141         ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_LRCPC_SHIFT, 4, 0),
 142         ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_FCMA_SHIFT, 4, 0),
 143         ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_JSCVT_SHIFT, 4, 0),
 144         ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_DPB_SHIFT, 4, 0),
 145         ARM64_FTR_END,
 146 };
 147
 148 static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = {
 149         ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_CSV3_SHIFT, 4, 0),
 150         ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_CSV2_SHIFT, 4, 0),
 151         ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
 152                                    FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_SVE_SHIFT, 4, 0),
 153         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_RAS_SHIFT, 4, 0),
 154         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_GIC_SHIFT, 4, 0),
 155         S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_ASIMD_SHIFT, 4, ID_AA64PFR0_ASIMD_NI),
 156         S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_FP_SHIFT, 4, ID_AA64PFR0_FP_NI),
 157         /* Linux doesn't care about the EL3 */
 158         ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL3_SHIFT, 4, 0),
 159         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL2_SHIFT, 4, 0),
 160         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_SHIFT, 4, ID_AA64PFR0_EL1_64BIT_ONLY),
 161         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL0_SHIFT, 4, ID_AA64PFR0_EL0_64BIT_ONLY),
 162         ARM64_FTR_END,
 163 };
 164
 165 static const struct arm64_ftr_bits ftr_id_aa64mmfr0[] = {
 166         S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN4_SHIFT, 4, ID_AA64MMFR0_TGRAN4_NI),
 167         S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN64_SHIFT, 4, ID_AA64MMFR0_TGRAN64_NI),
 168         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN16_SHIFT, 4, ID_AA64MMFR0_TGRAN16_NI),
 169         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_BIGENDEL0_SHIFT, 4, 0),
 170         /* Linux shouldn't care about secure memory */
 171         ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_SNSMEM_SHIFT, 4, 0),
 172         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_BIGENDEL_SHIFT, 4, 0),
 173         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_ASID_SHIFT, 4, 0),
 174         /*
 175          * Differing PARange is fine as long as all peripherals and memory are mapped
 176          * within the minimum PARange of all CPUs
 177          */
 178         ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_PARANGE_SHIFT, 4, 0),
 179         ARM64_FTR_END,
 180 };
 181
 182 static const struct arm64_ftr_bits ftr_id_aa64mmfr1[] = {
 183         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_PAN_SHIFT, 4, 0),
 184         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_LOR_SHIFT, 4, 0),
 185         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_HPD_SHIFT, 4, 0),
 186         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_VHE_SHIFT, 4, 0),
 187         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_VMIDBITS_SHIFT, 4, 0),
 188         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_HADBS_SHIFT, 4, 0),
 189         ARM64_FTR_END,
 190 };
 191
 192 static const struct arm64_ftr_bits ftr_id_aa64mmfr2[] = {
 193         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_LVA_SHIFT, 4, 0),
 194         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_IESB_SHIFT, 4, 0),
 195         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_LSM_SHIFT, 4, 0),
 196         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_UAO_SHIFT, 4, 0),
 197         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_CNP_SHIFT, 4, 0),
 198         ARM64_FTR_END,
 199 };
 200
 201 static const struct arm64_ftr_bits ftr_ctr[] = {
 202         ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, 31, 1, 1),   /* RAO */
 203         ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_SAFE, 24, 4, 0),     /* CWG */
 204         ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0),      /* ERG */
 205         ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 1),      /* DminLine */
 206         /*
 207          * Linux can handle differing I-cache policies. Userspace JITs will
 208          * make use of *minLine.
 209          * If we have differing I-cache policies, report it as the weakest - VIPT.
 210          */
 211         ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_EXACT, 14, 2, ICACHE_POLICY_VIPT),       /* L1Ip */
 212         ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),       /* IminLine */
 213         ARM64_FTR_END,
 214 };
 215
 216 struct arm64_ftr_reg arm64_ftr_reg_ctrel0 = {
 217         .name           = "SYS_CTR_EL0",
 218         .ftr_bits       = ftr_ctr
 219 };
 220
 221 static const struct arm64_ftr_bits ftr_id_mmfr0[] = {
 222         S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0xf),   /* InnerShr */
 223         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0),       /* FCSE */
 224         ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, 20, 4, 0),    /* AuxReg */
 225         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0),       /* TCM */
 226         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),       /* ShareLvl */
 227         S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0xf),    /* OuterShr */
 228         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),        /* PMSA */
 229         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),        /* VMSA */
 230         ARM64_FTR_END,
 231 };
 232
 233 static const struct arm64_ftr_bits ftr_id_aa64dfr0[] = {
 234         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 36, 28, 0),
 235         ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64DFR0_PMSVER_SHIFT, 4, 0),
 236         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_CTX_CMPS_SHIFT, 4, 0),
 237         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_WRPS_SHIFT, 4, 0),
 238         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_BRPS_SHIFT, 4, 0),
 239         /*
 240          * We can instantiate multiple PMU instances with different levels
 241          * of support.
 242          */
 243         S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64DFR0_PMUVER_SHIFT, 4, 0),
 244         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64DFR0_TRACEVER_SHIFT, 4, 0),
 245         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64DFR0_DEBUGVER_SHIFT, 4, 0x6),
 246         ARM64_FTR_END,
 247 };
 248
 249 static const struct arm64_ftr_bits ftr_mvfr2[] = {
 250         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),                /* FPMisc */
 251         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),                /* SIMDMisc */
 252         ARM64_FTR_END,
 253 };
 254
 255 static const struct arm64_ftr_bits ftr_dczid[] = {
 256         ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, 4, 1, 1),            /* DZP */
 257         ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),       /* BS */
 258         ARM64_FTR_END,
 259 };
 260
 261
 262 static const struct arm64_ftr_bits ftr_id_isar5[] = {
 263         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_RDM_SHIFT, 4, 0),
 264         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_CRC32_SHIFT, 4, 0),
 265         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SHA2_SHIFT, 4, 0),
 266         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SHA1_SHIFT, 4, 0),
 267         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_AES_SHIFT, 4, 0),
 268         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SEVL_SHIFT, 4, 0),
 269         ARM64_FTR_END,
 270 };
 271
 272 static const struct arm64_ftr_bits ftr_id_mmfr4[] = {
 273         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),        /* ac2 */
 274         ARM64_FTR_END,
 275 };
 276
 277 static const struct arm64_ftr_bits ftr_id_pfr0[] = {
 278         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),               /* State3 */
 279         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0),                /* State2 */
 280         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),                /* State1 */
 281         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),                /* State0 */
 282         ARM64_FTR_END,
 283 };
 284
 285 static const struct arm64_ftr_bits ftr_id_dfr0[] = {
 286         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0),
 287         S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0xf),   /* PerfMon */
 288         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0),
 289         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0),
 290         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),
 291         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0),
 292         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),
 293         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),
 294         ARM64_FTR_END,
 295 };
 296
 297 static const struct arm64_ftr_bits ftr_zcr[] = {
 298         ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE,
 299                 ZCR_ELx_LEN_SHIFT, ZCR_ELx_LEN_SIZE, 0),        /* LEN */
 300         ARM64_FTR_END,
 301 };
 302
 303 /*
 304  * Common ftr bits for a 32bit register with all hidden, strict
 305  * attributes, with 4bit feature fields and a default safe value of
 306  * 0. Covers the following 32bit registers:
 307  * id_isar[0-4], id_mmfr[1-3], id_pfr1, mvfr[0-1]
 308  */
 309 static const struct arm64_ftr_bits ftr_generic_32bits[] = {
 310         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0),
 311         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0),
 312         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0),
 313         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0),
 314         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),
 315         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0),
 316         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),
 317         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),
 318         ARM64_FTR_END,
 319 };
 320
 321 /* Table for a single 32bit feature value */
 322 static const struct arm64_ftr_bits ftr_single32[] = {
 323         ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 0, 32, 0),
 324         ARM64_FTR_END,
 325 };
 326
 327 static const struct arm64_ftr_bits ftr_raz[] = {
 328         ARM64_FTR_END,
 329 };
 330
 331 #define ARM64_FTR_REG(id, table) {              \
 332         .sys_id = id,                           \
 333         .reg =  &(struct arm64_ftr_reg){        \
 334                 .name = #id,                    \
 335                 .ftr_bits = &((table)[0]),      \
 336         }}
 337
 338 static const struct __ftr_reg_entry {
 339         u32                     sys_id;
 340         struct arm64_ftr_reg    *reg;
 341 } arm64_ftr_regs[] = {
 342
 343         /* Op1 = 0, CRn = 0, CRm = 1 */
 344         ARM64_FTR_REG(SYS_ID_PFR0_EL1, ftr_id_pfr0),
 345         ARM64_FTR_REG(SYS_ID_PFR1_EL1, ftr_generic_32bits),
 346         ARM64_FTR_REG(SYS_ID_DFR0_EL1, ftr_id_dfr0),
 347         ARM64_FTR_REG(SYS_ID_MMFR0_EL1, ftr_id_mmfr0),
 348         ARM64_FTR_REG(SYS_ID_MMFR1_EL1, ftr_generic_32bits),
 349         ARM64_FTR_REG(SYS_ID_MMFR2_EL1, ftr_generic_32bits),
 350         ARM64_FTR_REG(SYS_ID_MMFR3_EL1, ftr_generic_32bits),
 351
 352         /* Op1 = 0, CRn = 0, CRm = 2 */
 353         ARM64_FTR_REG(SYS_ID_ISAR0_EL1, ftr_generic_32bits),
 354         ARM64_FTR_REG(SYS_ID_ISAR1_EL1, ftr_generic_32bits),
 355         ARM64_FTR_REG(SYS_ID_ISAR2_EL1, ftr_generic_32bits),
 356         ARM64_FTR_REG(SYS_ID_ISAR3_EL1, ftr_generic_32bits),
 357         ARM64_FTR_REG(SYS_ID_ISAR4_EL1, ftr_generic_32bits),
 358         ARM64_FTR_REG(SYS_ID_ISAR5_EL1, ftr_id_isar5),
 359         ARM64_FTR_REG(SYS_ID_MMFR4_EL1, ftr_id_mmfr4),
 360
 361         /* Op1 = 0, CRn = 0, CRm = 3 */
 362         ARM64_FTR_REG(SYS_MVFR0_EL1, ftr_generic_32bits),
 363         ARM64_FTR_REG(SYS_MVFR1_EL1, ftr_generic_32bits),
 364         ARM64_FTR_REG(SYS_MVFR2_EL1, ftr_mvfr2),
 365
 366         /* Op1 = 0, CRn = 0, CRm = 4 */
 367         ARM64_FTR_REG(SYS_ID_AA64PFR0_EL1, ftr_id_aa64pfr0),
 368         ARM64_FTR_REG(SYS_ID_AA64PFR1_EL1, ftr_raz),
 369         ARM64_FTR_REG(SYS_ID_AA64ZFR0_EL1, ftr_raz),
 370
 371         /* Op1 = 0, CRn = 0, CRm = 5 */
 372         ARM64_FTR_REG(SYS_ID_AA64DFR0_EL1, ftr_id_aa64dfr0),
 373         ARM64_FTR_REG(SYS_ID_AA64DFR1_EL1, ftr_raz),
 374
 375         /* Op1 = 0, CRn = 0, CRm = 6 */
 376         ARM64_FTR_REG(SYS_ID_AA64ISAR0_EL1, ftr_id_aa64isar0),
 377         ARM64_FTR_REG(SYS_ID_AA64ISAR1_EL1, ftr_id_aa64isar1),
 378
 379         /* Op1 = 0, CRn = 0, CRm = 7 */
 380         ARM64_FTR_REG(SYS_ID_AA64MMFR0_EL1, ftr_id_aa64mmfr0),
 381         ARM64_FTR_REG(SYS_ID_AA64MMFR1_EL1, ftr_id_aa64mmfr1),
 382         ARM64_FTR_REG(SYS_ID_AA64MMFR2_EL1, ftr_id_aa64mmfr2),
 383
 384         /* Op1 = 0, CRn = 1, CRm = 2 */
 385         ARM64_FTR_REG(SYS_ZCR_EL1, ftr_zcr),
 386
 387         /* Op1 = 3, CRn = 0, CRm = 0 */
 388         { SYS_CTR_EL0, &arm64_ftr_reg_ctrel0 },
 389         ARM64_FTR_REG(SYS_DCZID_EL0, ftr_dczid),
 390
 391         /* Op1 = 3, CRn = 14, CRm = 0 */
 392         ARM64_FTR_REG(SYS_CNTFRQ_EL0, ftr_single32),
 393 };
 394
 395 static int search_cmp_ftr_reg(const void *id, const void *regp)
 396 {
 397         return (int)(unsigned long)id - (int)((const struct __ftr_reg_entry *)regp)->sys_id;
 398 }
 399
 400 /*
 401  * get_arm64_ftr_reg - Lookup a feature register entry using its
 402  * sys_reg() encoding. With the array arm64_ftr_regs sorted in the
 403  * ascending order of sys_id , we use binary search to find a matching
 404  * entry.
 405  *
 406  * returns - Upon success,  matching ftr_reg entry for id.
 407  *         - NULL on failure. It is upto the caller to decide
 408  *           the impact of a failure.
 409  */
 410 static struct arm64_ftr_reg *get_arm64_ftr_reg(u32 sys_id)
 411 {
 412         const struct __ftr_reg_entry *ret;
 413
 414         ret = bsearch((const void *)(unsigned long)sys_id,
 415                         arm64_ftr_regs,
 416                         ARRAY_SIZE(arm64_ftr_regs),
 417                         sizeof(arm64_ftr_regs[0]),
 418                         search_cmp_ftr_reg);
 419         if (ret)
 420                 return ret->reg;
 421         return NULL;
 422 }
 423
 424 static u64 arm64_ftr_set_value(const struct arm64_ftr_bits *ftrp, s64 reg,
 425                                s64 ftr_val)
 426 {
 427         u64 mask = arm64_ftr_mask(ftrp);
 428
 429         reg &= ~mask;
 430         reg |= (ftr_val << ftrp->shift) & mask;
 431         return reg;
 432 }
 433
 434 static s64 arm64_ftr_safe_value(const struct arm64_ftr_bits *ftrp, s64 new,
 435                                 s64 cur)
 436 {
 437         s64 ret = 0;
 438
 439         switch (ftrp->type) {
 440         case FTR_EXACT:
 441                 ret = ftrp->safe_val;
 442                 break;
 443         case FTR_LOWER_SAFE:
 444                 ret = new < cur ? new : cur;
 445                 break;
 446         case FTR_HIGHER_SAFE:
 447                 ret = new > cur ? new : cur;
 448                 break;
 449         default:
 450                 BUG();
 451         }
 452
 453         return ret;
 454 }
 455
 456 static void __init sort_ftr_regs(void)
 457 {
 458         int i;
 459
 460         /* Check that the array is sorted so that we can do the binary search */
 461         for (i = 1; i < ARRAY_SIZE(arm64_ftr_regs); i++)
 462                 BUG_ON(arm64_ftr_regs[i].sys_id < arm64_ftr_regs[i - 1].sys_id);
 463 }
 464
 465 /*
 466  * Initialise the CPU feature register from Boot CPU values.
 467  * Also initiliases the strict_mask for the register.
 468  * Any bits that are not covered by an arm64_ftr_bits entry are considered
 469  * RES0 for the system-wide value, and must strictly match.
 470  */
 471 static void __init init_cpu_ftr_reg(u32 sys_reg, u64 new)
 472 {
 473         u64 val = 0;
 474         u64 strict_mask = ~0x0ULL;
 475         u64 user_mask = 0;
 476         u64 valid_mask = 0;
 477
 478         const struct arm64_ftr_bits *ftrp;
 479         struct arm64_ftr_reg *reg = get_arm64_ftr_reg(sys_reg);
 480
 481         BUG_ON(!reg);
 482
 483         for (ftrp  = reg->ftr_bits; ftrp->width; ftrp++) {
 484                 u64 ftr_mask = arm64_ftr_mask(ftrp);
 485                 s64 ftr_new = arm64_ftr_value(ftrp, new);
 486
 487                 val = arm64_ftr_set_value(ftrp, val, ftr_new);
 488
 489                 valid_mask |= ftr_mask;
 490                 if (!ftrp->strict)
 491                         strict_mask &= ~ftr_mask;
 492                 if (ftrp->visible)
 493                         user_mask |= ftr_mask;
 494                 else
 495                         reg->user_val = arm64_ftr_set_value(ftrp,
 496                                                             reg->user_val,
 497                                                             ftrp->safe_val);
 498         }
 499
 500         val &= valid_mask;
 501
 502         reg->sys_val = val;
 503         reg->strict_mask = strict_mask;
 504         reg->user_mask = user_mask;
 505 }
 506
 507 void __init init_cpu_features(struct cpuinfo_arm64 *info)
 508 {
 509         /* Before we start using the tables, make sure it is sorted */
 510         sort_ftr_regs();
 511
 512         init_cpu_ftr_reg(SYS_CTR_EL0, info->reg_ctr);
 513         init_cpu_ftr_reg(SYS_DCZID_EL0, info->reg_dczid);
 514         init_cpu_ftr_reg(SYS_CNTFRQ_EL0, info->reg_cntfrq);
 515         init_cpu_ftr_reg(SYS_ID_AA64DFR0_EL1, info->reg_id_aa64dfr0);
 516         init_cpu_ftr_reg(SYS_ID_AA64DFR1_EL1, info->reg_id_aa64dfr1);
 517         init_cpu_ftr_reg(SYS_ID_AA64ISAR0_EL1, info->reg_id_aa64isar0);
 518         init_cpu_ftr_reg(SYS_ID_AA64ISAR1_EL1, info->reg_id_aa64isar1);
 519         init_cpu_ftr_reg(SYS_ID_AA64MMFR0_EL1, info->reg_id_aa64mmfr0);
 520         init_cpu_ftr_reg(SYS_ID_AA64MMFR1_EL1, info->reg_id_aa64mmfr1);
 521         init_cpu_ftr_reg(SYS_ID_AA64MMFR2_EL1, info->reg_id_aa64mmfr2);
 522         init_cpu_ftr_reg(SYS_ID_AA64PFR0_EL1, info->reg_id_aa64pfr0);
 523         init_cpu_ftr_reg(SYS_ID_AA64PFR1_EL1, info->reg_id_aa64pfr1);
 524         init_cpu_ftr_reg(SYS_ID_AA64ZFR0_EL1, info->reg_id_aa64zfr0);
 525
 526         if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0)) {
 527                 init_cpu_ftr_reg(SYS_ID_DFR0_EL1, info->reg_id_dfr0);
 528                 init_cpu_ftr_reg(SYS_ID_ISAR0_EL1, info->reg_id_isar0);
 529                 init_cpu_ftr_reg(SYS_ID_ISAR1_EL1, info->reg_id_isar1);
 530                 init_cpu_ftr_reg(SYS_ID_ISAR2_EL1, info->reg_id_isar2);
 531                 init_cpu_ftr_reg(SYS_ID_ISAR3_EL1, info->reg_id_isar3);
 532                 init_cpu_ftr_reg(SYS_ID_ISAR4_EL1, info->reg_id_isar4);
 533                 init_cpu_ftr_reg(SYS_ID_ISAR5_EL1, info->reg_id_isar5);
 534                 init_cpu_ftr_reg(SYS_ID_MMFR0_EL1, info->reg_id_mmfr0);
 535                 init_cpu_ftr_reg(SYS_ID_MMFR1_EL1, info->reg_id_mmfr1);
 536                 init_cpu_ftr_reg(SYS_ID_MMFR2_EL1, info->reg_id_mmfr2);
 537                 init_cpu_ftr_reg(SYS_ID_MMFR3_EL1, info->reg_id_mmfr3);
 538                 init_cpu_ftr_reg(SYS_ID_PFR0_EL1, info->reg_id_pfr0);
 539                 init_cpu_ftr_reg(SYS_ID_PFR1_EL1, info->reg_id_pfr1);
 540                 init_cpu_ftr_reg(SYS_MVFR0_EL1, info->reg_mvfr0);
 541                 init_cpu_ftr_reg(SYS_MVFR1_EL1, info->reg_mvfr1);
 542                 init_cpu_ftr_reg(SYS_MVFR2_EL1, info->reg_mvfr2);
 543         }
 544
 545         if (id_aa64pfr0_sve(info->reg_id_aa64pfr0)) {
 546                 init_cpu_ftr_reg(SYS_ZCR_EL1, info->reg_zcr);
 547                 sve_init_vq_map();
 548         }
 549 }
 550
 551 static void update_cpu_ftr_reg(struct arm64_ftr_reg *reg, u64 new)
 552 {
 553         const struct arm64_ftr_bits *ftrp;
 554
 555         for (ftrp = reg->ftr_bits; ftrp->width; ftrp++) {
 556                 s64 ftr_cur = arm64_ftr_value(ftrp, reg->sys_val);
 557                 s64 ftr_new = arm64_ftr_value(ftrp, new);
 558
 559                 if (ftr_cur == ftr_new)
 560                         continue;
 561                 /* Find a safe value */
 562                 ftr_new = arm64_ftr_safe_value(ftrp, ftr_new, ftr_cur);
 563                 reg->sys_val = arm64_ftr_set_value(ftrp, reg->sys_val, ftr_new);
 564         }
 565
 566 }
 567
 568 static int check_update_ftr_reg(u32 sys_id, int cpu, u64 val, u64 boot)
 569 {
 570         struct arm64_ftr_reg *regp = get_arm64_ftr_reg(sys_id);
 571
 572         BUG_ON(!regp);
 573         update_cpu_ftr_reg(regp, val);
 574         if ((boot & regp->strict_mask) == (val & regp->strict_mask))
 575                 return 0;
 576         pr_warn("SANITY CHECK: Unexpected variation in %s. Boot CPU: %#016llx, CPU%d: %#016llx\n",
 577                         regp->name, boot, cpu, val);
 578         return 1;
 579 }
 580
 581 /*
 582  * Update system wide CPU feature registers with the values from a
 583  * non-boot CPU. Also performs SANITY checks to make sure that there
 584  * aren't any insane variations from that of the boot CPU.
 585  */
 586 void update_cpu_features(int cpu,
 587                          struct cpuinfo_arm64 *info,
 588                          struct cpuinfo_arm64 *boot)
 589 {
 590         int taint = 0;
 591
 592         /*
 593          * The kernel can handle differing I-cache policies, but otherwise
 594          * caches should look identical. Userspace JITs will make use of
 595          * *minLine.
 596          */
 597         taint |= check_update_ftr_reg(SYS_CTR_EL0, cpu,
 598                                       info->reg_ctr, boot->reg_ctr);
 599
 600         /*
 601          * Userspace may perform DC ZVA instructions. Mismatched block sizes
 602          * could result in too much or too little memory being zeroed if a
 603          * process is preempted and migrated between CPUs.
 604          */
 605         taint |= check_update_ftr_reg(SYS_DCZID_EL0, cpu,
 606                                       info->reg_dczid, boot->reg_dczid);
 607
 608         /* If different, timekeeping will be broken (especially with KVM) */
 609         taint |= check_update_ftr_reg(SYS_CNTFRQ_EL0, cpu,
 610                                       info->reg_cntfrq, boot->reg_cntfrq);
 611
 612         /*
 613          * The kernel uses self-hosted debug features and expects CPUs to
 614          * support identical debug features. We presently need CTX_CMPs, WRPs,
 615          * and BRPs to be identical.
 616          * ID_AA64DFR1 is currently RES0.
 617          */
 618         taint |= check_update_ftr_reg(SYS_ID_AA64DFR0_EL1, cpu,
 619                                       info->reg_id_aa64dfr0, boot->reg_id_aa64dfr0);
 620         taint |= check_update_ftr_reg(SYS_ID_AA64DFR1_EL1, cpu,
 621                                       info->reg_id_aa64dfr1, boot->reg_id_aa64dfr1);
 622         /*
 623          * Even in big.LITTLE, processors should be identical instruction-set
 624          * wise.
 625          */
 626         taint |= check_update_ftr_reg(SYS_ID_AA64ISAR0_EL1, cpu,
 627                                       info->reg_id_aa64isar0, boot->reg_id_aa64isar0);
 628         taint |= check_update_ftr_reg(SYS_ID_AA64ISAR1_EL1, cpu,
 629                                       info->reg_id_aa64isar1, boot->reg_id_aa64isar1);
 630
 631         /*
 632          * Differing PARange support is fine as long as all peripherals and
 633          * memory are mapped within the minimum PARange of all CPUs.
 634          * Linux should not care about secure memory.
 635          */
 636         taint |= check_update_ftr_reg(SYS_ID_AA64MMFR0_EL1, cpu,
 637                                       info->reg_id_aa64mmfr0, boot->reg_id_aa64mmfr0);
 638         taint |= check_update_ftr_reg(SYS_ID_AA64MMFR1_EL1, cpu,
 639                                       info->reg_id_aa64mmfr1, boot->reg_id_aa64mmfr1);
 640         taint |= check_update_ftr_reg(SYS_ID_AA64MMFR2_EL1, cpu,
 641                                       info->reg_id_aa64mmfr2, boot->reg_id_aa64mmfr2);
 642
 643         /*
 644          * EL3 is not our concern.
 645          * ID_AA64PFR1 is currently RES0.
 646          */
 647         taint |= check_update_ftr_reg(SYS_ID_AA64PFR0_EL1, cpu,
 648                                       info->reg_id_aa64pfr0, boot->reg_id_aa64pfr0);
 649         taint |= check_update_ftr_reg(SYS_ID_AA64PFR1_EL1, cpu,
 650                                       info->reg_id_aa64pfr1, boot->reg_id_aa64pfr1);
 651
 652         taint |= check_update_ftr_reg(SYS_ID_AA64ZFR0_EL1, cpu,
 653                                       info->reg_id_aa64zfr0, boot->reg_id_aa64zfr0);
 654
 655         /*
 656          * If we have AArch32, we care about 32-bit features for compat.
 657          * If the system doesn't support AArch32, don't update them.
 658          */
 659         if (id_aa64pfr0_32bit_el0(read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1)) &&
 660                 id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0)) {
 661
 662                 taint |= check_update_ftr_reg(SYS_ID_DFR0_EL1, cpu,
 663                                         info->reg_id_dfr0, boot->reg_id_dfr0);
 664                 taint |= check_update_ftr_reg(SYS_ID_ISAR0_EL1, cpu,
 665                                         info->reg_id_isar0, boot->reg_id_isar0);
 666                 taint |= check_update_ftr_reg(SYS_ID_ISAR1_EL1, cpu,
 667                                         info->reg_id_isar1, boot->reg_id_isar1);
 668                 taint |= check_update_ftr_reg(SYS_ID_ISAR2_EL1, cpu,
 669                                         info->reg_id_isar2, boot->reg_id_isar2);
 670                 taint |= check_update_ftr_reg(SYS_ID_ISAR3_EL1, cpu,
 671                                         info->reg_id_isar3, boot->reg_id_isar3);
 672                 taint |= check_update_ftr_reg(SYS_ID_ISAR4_EL1, cpu,
 673                                         info->reg_id_isar4, boot->reg_id_isar4);
 674                 taint |= check_update_ftr_reg(SYS_ID_ISAR5_EL1, cpu,
 675                                         info->reg_id_isar5, boot->reg_id_isar5);
 676
 677                 /*
 678                  * Regardless of the value of the AuxReg field, the AIFSR, ADFSR, and
 679                  * ACTLR formats could differ across CPUs and therefore would have to
 680                  * be trapped for virtualization anyway.
 681                  */
 682                 taint |= check_update_ftr_reg(SYS_ID_MMFR0_EL1, cpu,
 683                                         info->reg_id_mmfr0, boot->reg_id_mmfr0);
 684                 taint |= check_update_ftr_reg(SYS_ID_MMFR1_EL1, cpu,
 685                                         info->reg_id_mmfr1, boot->reg_id_mmfr1);
 686                 taint |= check_update_ftr_reg(SYS_ID_MMFR2_EL1, cpu,
 687                                         info->reg_id_mmfr2, boot->reg_id_mmfr2);
 688                 taint |= check_update_ftr_reg(SYS_ID_MMFR3_EL1, cpu,
 689                                         info->reg_id_mmfr3, boot->reg_id_mmfr3);
 690                 taint |= check_update_ftr_reg(SYS_ID_PFR0_EL1, cpu,
 691                                         info->reg_id_pfr0, boot->reg_id_pfr0);
 692                 taint |= check_update_ftr_reg(SYS_ID_PFR1_EL1, cpu,
 693                                         info->reg_id_pfr1, boot->reg_id_pfr1);
 694                 taint |= check_update_ftr_reg(SYS_MVFR0_EL1, cpu,
 695                                         info->reg_mvfr0, boot->reg_mvfr0);
 696                 taint |= check_update_ftr_reg(SYS_MVFR1_EL1, cpu,
 697                                         info->reg_mvfr1, boot->reg_mvfr1);
 698                 taint |= check_update_ftr_reg(SYS_MVFR2_EL1, cpu,
 699                                         info->reg_mvfr2, boot->reg_mvfr2);
 700         }
 701
 702         if (id_aa64pfr0_sve(info->reg_id_aa64pfr0)) {
 703                 taint |= check_update_ftr_reg(SYS_ZCR_EL1, cpu,
 704                                         info->reg_zcr, boot->reg_zcr);
 705
 706                 /* Probe vector lengths, unless we already gave up on SVE */
 707                 if (id_aa64pfr0_sve(read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1)) &&
 708                     !sys_caps_initialised)
 709                         sve_update_vq_map();
 710         }
 711
 712         /*
 713          * Mismatched CPU features are a recipe for disaster. Don't even
 714          * pretend to support them.
 715          */
 716         if (taint) {
 717                 pr_warn_once("Unsupported CPU feature variation detected.\n");
 718                 add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK);
 719         }
 720 }
 721
 722 u64 read_sanitised_ftr_reg(u32 id)
 723 {
 724         struct arm64_ftr_reg *regp = get_arm64_ftr_reg(id);
 725
 726         /* We shouldn't get a request for an unsupported register */
 727         BUG_ON(!regp);
 728         return regp->sys_val;
 729 }
 730
 731 #define read_sysreg_case(r)     \
 732         case r:         return read_sysreg_s(r)
 733
 734 /*
 735  * __read_sysreg_by_encoding() - Used by a STARTING cpu before cpuinfo is populated.
 736  * Read the system register on the current CPU
 737  */
 738 static u64 __read_sysreg_by_encoding(u32 sys_id)
 739 {
 740         switch (sys_id) {
 741         read_sysreg_case(SYS_ID_PFR0_EL1);
 742         read_sysreg_case(SYS_ID_PFR1_EL1);
 743         read_sysreg_case(SYS_ID_DFR0_EL1);
 744         read_sysreg_case(SYS_ID_MMFR0_EL1);
 745         read_sysreg_case(SYS_ID_MMFR1_EL1);
 746         read_sysreg_case(SYS_ID_MMFR2_EL1);
 747         read_sysreg_case(SYS_ID_MMFR3_EL1);
 748         read_sysreg_case(SYS_ID_ISAR0_EL1);
 749         read_sysreg_case(SYS_ID_ISAR1_EL1);
 750         read_sysreg_case(SYS_ID_ISAR2_EL1);
 751         read_sysreg_case(SYS_ID_ISAR3_EL1);
 752         read_sysreg_case(SYS_ID_ISAR4_EL1);
 753         read_sysreg_case(SYS_ID_ISAR5_EL1);
 754         read_sysreg_case(SYS_MVFR0_EL1);
 755         read_sysreg_case(SYS_MVFR1_EL1);
 756         read_sysreg_case(SYS_MVFR2_EL1);
 757
 758         read_sysreg_case(SYS_ID_AA64PFR0_EL1);
 759         read_sysreg_case(SYS_ID_AA64PFR1_EL1);
 760         read_sysreg_case(SYS_ID_AA64DFR0_EL1);
 761         read_sysreg_case(SYS_ID_AA64DFR1_EL1);
 762         read_sysreg_case(SYS_ID_AA64MMFR0_EL1);
 763         read_sysreg_case(SYS_ID_AA64MMFR1_EL1);
 764         read_sysreg_case(SYS_ID_AA64MMFR2_EL1);
 765         read_sysreg_case(SYS_ID_AA64ISAR0_EL1);
 766         read_sysreg_case(SYS_ID_AA64ISAR1_EL1);
 767
 768         read_sysreg_case(SYS_CNTFRQ_EL0);
 769         read_sysreg_case(SYS_CTR_EL0);
 770         read_sysreg_case(SYS_DCZID_EL0);
 771
 772         default:
 773                 BUG();
 774                 return 0;
 775         }
 776 }
 777
 778 #include <linux/irqchip/arm-gic-v3.h>
 779
 780 static bool
 781 feature_matches(u64 reg, const struct arm64_cpu_capabilities *entry)
 782 {
 783         int val = cpuid_feature_extract_field(reg, entry->field_pos, entry->sign);
 784
 785         return val >= entry->min_field_value;
 786 }
 787
 788 static bool
 789 has_cpuid_feature(const struct arm64_cpu_capabilities *entry, int scope)
 790 {
 791         u64 val;
 792
 793         WARN_ON(scope == SCOPE_LOCAL_CPU && preemptible());
 794         if (scope == SCOPE_SYSTEM)
 795                 val = read_sanitised_ftr_reg(entry->sys_reg);
 796         else
 797                 val = __read_sysreg_by_encoding(entry->sys_reg);
 798
 799         return feature_matches(val, entry);
 800 }
 801
 802 static bool has_useable_gicv3_cpuif(const struct arm64_cpu_capabilities *entry, int scope)
 803 {
 804         bool has_sre;
 805
 806         if (!has_cpuid_feature(entry, scope))
 807                 return false;
 808
 809         has_sre = gic_enable_sre();
 810         if (!has_sre)
 811                 pr_warn_once("%s present but disabled by higher exception level\n",
 812                              entry->desc);
 813
 814         return has_sre;
 815 }
 816
 817 static bool has_no_hw_prefetch(const struct arm64_cpu_capabilities *entry, int __unused)
 818 {
 819         u32 midr = read_cpuid_id();
 820
 821         /* Cavium ThunderX pass 1.x and 2.x */
 822         return MIDR_IS_CPU_MODEL_RANGE(midr, MIDR_THUNDERX,
 823                 MIDR_CPU_VAR_REV(0, 0),
 824                 MIDR_CPU_VAR_REV(1, MIDR_REVISION_MASK));
 825 }
 826
 827 static bool runs_at_el2(const struct arm64_cpu_capabilities *entry, int __unused)
 828 {
 829         return is_kernel_in_hyp_mode();
 830 }
 831
 832 static bool hyp_offset_low(const struct arm64_cpu_capabilities *entry,
 833                            int __unused)
 834 {
 835         phys_addr_t idmap_addr = __pa_symbol(__hyp_idmap_text_start);
 836
 837         /*
 838          * Activate the lower HYP offset only if:
 839          * - the idmap doesn't clash with it,
 840          * - the kernel is not running at EL2.
 841          */
 842         return idmap_addr > GENMASK(VA_BITS - 2, 0) && !is_kernel_in_hyp_mode();
 843 }
 844
 845 static bool has_no_fpsimd(const struct arm64_cpu_capabilities *entry, int __unused)
 846 {
 847         u64 pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
 848
 849         return cpuid_feature_extract_signed_field(pfr0,
 850                                         ID_AA64PFR0_FP_SHIFT) < 0;
 851 }
 852
 853 #ifdef CONFIG_UNMAP_KERNEL_AT_EL0
 854 static int __kpti_forced; /* 0: not forced, >0: forced on, <0: forced off */
 855
 856 static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
 857                                 int __unused)
 858 {
 859         char const *str = "command line option";
 860         u64 pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
 861
 862         /*
 863          * For reasons that aren't entirely clear, enabling KPTI on Cavium
 864          * ThunderX leads to apparent I-cache corruption of kernel text, which
 865          * ends as well as you might imagine. Don't even try.
 866          */
 867         if (cpus_have_const_cap(ARM64_WORKAROUND_CAVIUM_27456)) {
 868                 str = "ARM64_WORKAROUND_CAVIUM_27456";
 869                 __kpti_forced = -1;
 870         }
 871
 872         /* Forced? */
 873         if (__kpti_forced) {
 874                 pr_info_once("kernel page table isolation forced %s by %s\n",
 875                              __kpti_forced > 0 ? "ON" : "OFF", str);
 876                 return __kpti_forced > 0;
 877         }
 878
 879         /* Useful for KASLR robustness */
 880         if (IS_ENABLED(CONFIG_RANDOMIZE_BASE))
 881                 return true;
 882
 883         /* Don't force KPTI for CPUs that are not vulnerable */
 884         switch (read_cpuid_id() & MIDR_CPU_MODEL_MASK) {
 885         case MIDR_CAVIUM_THUNDERX2:
 886         case MIDR_BRCM_VULCAN:
 887                 return false;
 888         }
 889
 890         /* Defer to CPU feature registers */
 891         return !cpuid_feature_extract_unsigned_field(pfr0,
 892                                                      ID_AA64PFR0_CSV3_SHIFT);
 893 }
 894
 895 static int kpti_install_ng_mappings(void *__unused)
 896 {
 897         typedef void (kpti_remap_fn)(int, int, phys_addr_t);
 898         extern kpti_remap_fn idmap_kpti_install_ng_mappings;
 899         kpti_remap_fn *remap_fn;
 900
 901         static bool kpti_applied = false;
 902         int cpu = smp_processor_id();
 903
 904         if (kpti_applied)
 905                 return 0;
 906
 907         remap_fn = (void *)__pa_symbol(idmap_kpti_install_ng_mappings);
 908
 909         cpu_install_idmap();
 910         remap_fn(cpu, num_online_cpus(), __pa_symbol(swapper_pg_dir));
 911         cpu_uninstall_idmap();
 912
 913         if (!cpu)
 914                 kpti_applied = true;
 915
 916         return 0;
 917 }
 918
 919 static int __init parse_kpti(char *str)
 920 {
 921         bool enabled;
 922         int ret = strtobool(str, &enabled);
 923
 924         if (ret)
 925                 return ret;
 926
 927         __kpti_forced = enabled ? 1 : -1;
 928         return 0;
 929 }
 930 __setup("kpti=", parse_kpti);
 931 #endif  /* CONFIG_UNMAP_KERNEL_AT_EL0 */
 932
 933 static int cpu_copy_el2regs(void *__unused)
 934 {
 935         /*
 936          * Copy register values that aren't redirected by hardware.
 937          *
 938          * Before code patching, we only set tpidr_el1, all CPUs need to copy
 939          * this value to tpidr_el2 before we patch the code. Once we've done
 940          * that, freshly-onlined CPUs will set tpidr_el2, so we don't need to
 941          * do anything here.
 942          */
 943         if (!alternatives_applied)
 944                 write_sysreg(read_sysreg(tpidr_el1), tpidr_el2);
 945
 946         return 0;
 947 }
 948
 949 static const struct arm64_cpu_capabilities arm64_features[] = {
 950         {
 951                 .desc = "GIC system register CPU interface",
 952                 .capability = ARM64_HAS_SYSREG_GIC_CPUIF,
 953                 .def_scope = SCOPE_SYSTEM,
 954                 .matches = has_useable_gicv3_cpuif,
 955                 .sys_reg = SYS_ID_AA64PFR0_EL1,
 956                 .field_pos = ID_AA64PFR0_GIC_SHIFT,
 957                 .sign = FTR_UNSIGNED,
 958                 .min_field_value = 1,
 959         },
 960 #ifdef CONFIG_ARM64_PAN
 961         {
 962                 .desc = "Privileged Access Never",
 963                 .capability = ARM64_HAS_PAN,
 964                 .def_scope = SCOPE_SYSTEM,
 965                 .matches = has_cpuid_feature,
 966                 .sys_reg = SYS_ID_AA64MMFR1_EL1,
 967                 .field_pos = ID_AA64MMFR1_PAN_SHIFT,
 968                 .sign = FTR_UNSIGNED,
 969                 .min_field_value = 1,
 970                 .enable = cpu_enable_pan,
 971         },
 972 #endif /* CONFIG_ARM64_PAN */
 973 #if defined(CONFIG_AS_LSE) && defined(CONFIG_ARM64_LSE_ATOMICS)
 974         {
 975                 .desc = "LSE atomic instructions",
 976                 .capability = ARM64_HAS_LSE_ATOMICS,
 977                 .def_scope = SCOPE_SYSTEM,
 978                 .matches = has_cpuid_feature,
 979                 .sys_reg = SYS_ID_AA64ISAR0_EL1,
 980                 .field_pos = ID_AA64ISAR0_ATOMICS_SHIFT,
 981                 .sign = FTR_UNSIGNED,
 982                 .min_field_value = 2,
 983         },
 984 #endif /* CONFIG_AS_LSE && CONFIG_ARM64_LSE_ATOMICS */
 985         {
 986                 .desc = "Software prefetching using PRFM",
 987                 .capability = ARM64_HAS_NO_HW_PREFETCH,
 988                 .def_scope = SCOPE_SYSTEM,
 989                 .matches = has_no_hw_prefetch,
 990         },
 991 #ifdef CONFIG_ARM64_UAO
 992         {
 993                 .desc = "User Access Override",
 994                 .capability = ARM64_HAS_UAO,
 995                 .def_scope = SCOPE_SYSTEM,
 996                 .matches = has_cpuid_feature,
 997                 .sys_reg = SYS_ID_AA64MMFR2_EL1,
 998                 .field_pos = ID_AA64MMFR2_UAO_SHIFT,
 999                 .min_field_value = 1,
1000                 /*
1001                  * We rely on stop_machine() calling uao_thread_switch() to set
1002                  * UAO immediately after patching.
1003                  */
1004         },
1005 #endif /* CONFIG_ARM64_UAO */
1006 #ifdef CONFIG_ARM64_PAN
1007         {
1008                 .capability = ARM64_ALT_PAN_NOT_UAO,
1009                 .def_scope = SCOPE_SYSTEM,
1010                 .matches = cpufeature_pan_not_uao,
1011         },
1012 #endif /* CONFIG_ARM64_PAN */
1013         {
1014                 .desc = "Virtualization Host Extensions",
1015                 .capability = ARM64_HAS_VIRT_HOST_EXTN,
1016                 .def_scope = SCOPE_SYSTEM,
1017                 .matches = runs_at_el2,
1018                 .enable = cpu_copy_el2regs,
1019         },
1020         {
1021                 .desc = "32-bit EL0 Support",
1022                 .capability = ARM64_HAS_32BIT_EL0,
1023                 .def_scope = SCOPE_SYSTEM,
1024                 .matches = has_cpuid_feature,
1025                 .sys_reg = SYS_ID_AA64PFR0_EL1,
1026                 .sign = FTR_UNSIGNED,
1027                 .field_pos = ID_AA64PFR0_EL0_SHIFT,
1028                 .min_field_value = ID_AA64PFR0_EL0_32BIT_64BIT,
1029         },
1030         {
1031                 .desc = "Reduced HYP mapping offset",
1032                 .capability = ARM64_HYP_OFFSET_LOW,
1033                 .def_scope = SCOPE_SYSTEM,
1034                 .matches = hyp_offset_low,
1035         },
1036 #ifdef CONFIG_UNMAP_KERNEL_AT_EL0
1037         {
1038                 .desc = "Kernel page table isolation (KPTI)",
1039                 .capability = ARM64_UNMAP_KERNEL_AT_EL0,
1040                 .def_scope = SCOPE_SYSTEM,
1041                 .matches = unmap_kernel_at_el0,
1042                 .enable = kpti_install_ng_mappings,
1043         },
1044 #endif
1045         {
1046                 /* FP/SIMD is not implemented */
1047                 .capability = ARM64_HAS_NO_FPSIMD,
1048                 .def_scope = SCOPE_SYSTEM,
1049                 .min_field_value = 0,
1050                 .matches = has_no_fpsimd,
1051         },
1052 #ifdef CONFIG_ARM64_PMEM
1053         {
1054                 .desc = "Data cache clean to Point of Persistence",
1055                 .capability = ARM64_HAS_DCPOP,
1056                 .def_scope = SCOPE_SYSTEM,
1057                 .matches = has_cpuid_feature,
1058                 .sys_reg = SYS_ID_AA64ISAR1_EL1,
1059                 .field_pos = ID_AA64ISAR1_DPB_SHIFT,
1060                 .min_field_value = 1,
1061         },
1062 #endif
1063 #ifdef CONFIG_ARM64_SVE
1064         {
1065                 .desc = "Scalable Vector Extension",
1066                 .capability = ARM64_SVE,
1067                 .def_scope = SCOPE_SYSTEM,
1068                 .sys_reg = SYS_ID_AA64PFR0_EL1,
1069                 .sign = FTR_UNSIGNED,
1070                 .field_pos = ID_AA64PFR0_SVE_SHIFT,
1071                 .min_field_value = ID_AA64PFR0_SVE,
1072                 .matches = has_cpuid_feature,
1073                 .enable = sve_kernel_enable,
1074         },
1075 #endif /* CONFIG_ARM64_SVE */
1076 #ifdef CONFIG_ARM64_RAS_EXTN
1077         {
1078                 .desc = "RAS Extension Support",
1079                 .capability = ARM64_HAS_RAS_EXTN,
1080                 .def_scope = SCOPE_SYSTEM,
1081                 .matches = has_cpuid_feature,
1082                 .sys_reg = SYS_ID_AA64PFR0_EL1,
1083                 .sign = FTR_UNSIGNED,
1084                 .field_pos = ID_AA64PFR0_RAS_SHIFT,
1085                 .min_field_value = ID_AA64PFR0_RAS_V1,
1086                 .enable = cpu_clear_disr,
1087         },
1088 #endif /* CONFIG_ARM64_RAS_EXTN */
1089         {},
1090 };
1091
1092 #define HWCAP_CAP(reg, field, s, min_value, type, cap)  \
1093         {                                                       \
1094                 .desc = #cap,                                   \
1095                 .def_scope = SCOPE_SYSTEM,                      \
1096                 .matches = has_cpuid_feature,                   \
1097                 .sys_reg = reg,                                 \
1098                 .field_pos = field,                             \
1099                 .sign = s,                                      \
1100                 .min_field_value = min_value,                   \
1101                 .hwcap_type = type,                             \
1102                 .hwcap = cap,                                   \
1103         }
1104
1105 static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
1106         HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_AES_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, HWCAP_PMULL),
1107         HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_AES_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_AES),
1108         HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA1_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_SHA1),
1109         HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA2_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_SHA2),
1110         HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA2_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, HWCAP_SHA512),
1111         HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_CRC32_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_CRC32),
1112         HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_ATOMICS_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, HWCAP_ATOMICS),
1113         HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_RDM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_ASIMDRDM),
1114         HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA3_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_SHA3),
1115         HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SM3_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_SM3),
1116         HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SM4_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_SM4),
1117         HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_DP_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_ASIMDDP),
1118         HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_FHM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_ASIMDFHM),
1119         HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, FTR_SIGNED, 0, CAP_HWCAP, HWCAP_FP),
1120         HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, HWCAP_FPHP),
1121         HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, FTR_SIGNED, 0, CAP_HWCAP, HWCAP_ASIMD),
1122         HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, HWCAP_ASIMDHP),
1123         HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DPB_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_DCPOP),
1124         HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_JSCVT_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_JSCVT),
1125         HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_FCMA_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_FCMA),
1126         HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_LRCPC_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_LRCPC),
1127 #ifdef CONFIG_ARM64_SVE
1128         HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_SVE_SHIFT, FTR_UNSIGNED, ID_AA64PFR0_SVE, CAP_HWCAP, HWCAP_SVE),
1129 #endif
1130         {},
1131 };
1132
1133 static const struct arm64_cpu_capabilities compat_elf_hwcaps[] = {
1134 #ifdef CONFIG_COMPAT
1135         HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, FTR_UNSIGNED, 2, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_PMULL),
1136         HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_AES),
1137         HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA1_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA1),
1138         HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA2_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA2),
1139         HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_CRC32_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_CRC32),
1140 #endif
1141         {},
1142 };
1143
1144 static void __init cap_set_elf_hwcap(const struct arm64_cpu_capabilities *cap)
1145 {
1146         switch (cap->hwcap_type) {
1147         case CAP_HWCAP:
1148                 elf_hwcap |= cap->hwcap;
1149                 break;
1150 #ifdef CONFIG_COMPAT
1151         case CAP_COMPAT_HWCAP:
1152                 compat_elf_hwcap |= (u32)cap->hwcap;
1153                 break;
1154         case CAP_COMPAT_HWCAP2:
1155                 compat_elf_hwcap2 |= (u32)cap->hwcap;
1156                 break;
1157 #endif
1158         default:
1159                 WARN_ON(1);
1160                 break;
1161         }
1162 }
1163
1164 /* Check if we have a particular HWCAP enabled */
1165 static bool cpus_have_elf_hwcap(const struct arm64_cpu_capabilities *cap)
1166 {
1167         bool rc;
1168
1169         switch (cap->hwcap_type) {
1170         case CAP_HWCAP:
1171                 rc = (elf_hwcap & cap->hwcap) != 0;
1172                 break;
1173 #ifdef CONFIG_COMPAT
1174         case CAP_COMPAT_HWCAP:
1175                 rc = (compat_elf_hwcap & (u32)cap->hwcap) != 0;
1176                 break;
1177         case CAP_COMPAT_HWCAP2:
1178                 rc = (compat_elf_hwcap2 & (u32)cap->hwcap) != 0;
1179                 break;
1180 #endif
1181         default:
1182                 WARN_ON(1);
1183                 rc = false;
1184         }
1185
1186         return rc;
1187 }
1188
1189 static void __init setup_elf_hwcaps(const struct arm64_cpu_capabilities *hwcaps)
1190 {
1191         /* We support emulation of accesses to CPU ID feature registers */
1192         elf_hwcap |= HWCAP_CPUID;
1193         for (; hwcaps->matches; hwcaps++)
1194                 if (hwcaps->matches(hwcaps, hwcaps->def_scope))
1195                         cap_set_elf_hwcap(hwcaps);
1196 }
1197
1198 /*
1199  * Check if the current CPU has a given feature capability.
1200  * Should be called from non-preemptible context.
1201  */
1202 static bool __this_cpu_has_cap(const struct arm64_cpu_capabilities *cap_array,
1203                                unsigned int cap)
1204 {
1205         const struct arm64_cpu_capabilities *caps;
1206
1207         if (WARN_ON(preemptible()))
1208                 return false;
1209
1210         for (caps = cap_array; caps->matches; caps++)
1211                 if (caps->capability == cap &&
1212                     caps->matches(caps, SCOPE_LOCAL_CPU))
1213                         return true;
1214         return false;
1215 }
1216
1217 void update_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
1218                             const char *info)
1219 {
1220         for (; caps->matches; caps++) {
1221                 if (!caps->matches(caps, caps->def_scope))
1222                         continue;
1223
1224                 if (!cpus_have_cap(caps->capability) && caps->desc)
1225                         pr_info("%s %s\n", info, caps->desc);
1226                 cpus_set_cap(caps->capability);
1227         }
1228 }
1229
1230 /*
1231  * Run through the enabled capabilities and enable() it on all active
1232  * CPUs
1233  */
1234 void __init enable_cpu_capabilities(const struct arm64_cpu_capabilities *caps)
1235 {
1236         for (; caps->matches; caps++) {
1237                 unsigned int num = caps->capability;
1238
1239                 if (!cpus_have_cap(num))
1240                         continue;
1241
1242                 /* Ensure cpus_have_const_cap(num) works */
1243                 static_branch_enable(&cpu_hwcap_keys[num]);
1244
1245                 if (caps->enable) {
1246                         /*
1247                          * Use stop_machine() as it schedules the work allowing
1248                          * us to modify PSTATE, instead of on_each_cpu() which
1249                          * uses an IPI, giving us a PSTATE that disappears when
1250                          * we return.
1251                          */
1252                         stop_machine(caps->enable, (void *)caps, cpu_online_mask);
1253                 }
1254         }
1255 }
1256
1257 /*
1258  * Check for CPU features that are used in early boot
1259  * based on the Boot CPU value.
1260  */
1261 static void check_early_cpu_features(void)
1262 {
1263         verify_cpu_run_el();
1264         verify_cpu_asid_bits();
1265 }
1266
1267 static void
1268 verify_local_elf_hwcaps(const struct arm64_cpu_capabilities *caps)
1269 {
1270
1271         for (; caps->matches; caps++)
1272                 if (cpus_have_elf_hwcap(caps) && !caps->matches(caps, SCOPE_LOCAL_CPU)) {
1273                         pr_crit("CPU%d: missing HWCAP: %s\n",
1274                                         smp_processor_id(), caps->desc);
1275                         cpu_die_early();
1276                 }
1277 }
1278
1279 static void
1280 verify_local_cpu_features(const struct arm64_cpu_capabilities *caps_list)
1281 {
1282         const struct arm64_cpu_capabilities *caps = caps_list;
1283         for (; caps->matches; caps++) {
1284                 if (!cpus_have_cap(caps->capability))
1285                         continue;
1286                 /*
1287                  * If the new CPU misses an advertised feature, we cannot proceed
1288                  * further, park the cpu.
1289                  */
1290                 if (!__this_cpu_has_cap(caps_list, caps->capability)) {
1291                         pr_crit("CPU%d: missing feature: %s\n",
1292                                         smp_processor_id(), caps->desc);
1293                         cpu_die_early();
1294                 }
1295                 if (caps->enable)
1296                         caps->enable((void *)caps);
1297         }
1298 }
1299
1300 static void verify_sve_features(void)
1301 {
1302         u64 safe_zcr = read_sanitised_ftr_reg(SYS_ZCR_EL1);
1303         u64 zcr = read_zcr_features();
1304
1305         unsigned int safe_len = safe_zcr & ZCR_ELx_LEN_MASK;
1306         unsigned int len = zcr & ZCR_ELx_LEN_MASK;
1307
1308         if (len < safe_len || sve_verify_vq_map()) {
1309                 pr_crit("CPU%d: SVE: required vector length(s) missing\n",
1310                         smp_processor_id());
1311                 cpu_die_early();
1312         }
1313
1314         /* Add checks on other ZCR bits here if necessary */
1315 }
1316
1317 /*
1318  * Run through the enabled system capabilities and enable() it on this CPU.
1319  * The capabilities were decided based on the available CPUs at the boot time.
1320  * Any new CPU should match the system wide status of the capability. If the
1321  * new CPU doesn't have a capability which the system now has enabled, we
1322  * cannot do anything to fix it up and could cause unexpected failures. So
1323  * we park the CPU.
1324  */
1325 static void verify_local_cpu_capabilities(void)
1326 {
1327         verify_local_cpu_errata_workarounds();
1328         verify_local_cpu_features(arm64_features);
1329         verify_local_elf_hwcaps(arm64_elf_hwcaps);
1330
1331         if (system_supports_32bit_el0())
1332                 verify_local_elf_hwcaps(compat_elf_hwcaps);
1333
1334         if (system_supports_sve())
1335                 verify_sve_features();
1336
1337         if (system_uses_ttbr0_pan())
1338                 pr_info("Emulating Privileged Access Never (PAN) using TTBR0_EL1 switching\n");
1339 }
1340
1341 void check_local_cpu_capabilities(void)
1342 {
1343         /*
1344          * All secondary CPUs should conform to the early CPU features
1345          * in use by the kernel based on boot CPU.
1346          */
1347         check_early_cpu_features();
1348
1349         /*
1350          * If we haven't finalised the system capabilities, this CPU gets
1351          * a chance to update the errata work arounds.
1352          * Otherwise, this CPU should verify that it has all the system
1353          * advertised capabilities.
1354          */
1355         if (!sys_caps_initialised)
1356                 update_cpu_errata_workarounds();
1357         else
1358                 verify_local_cpu_capabilities();
1359 }
1360
1361 static void __init setup_feature_capabilities(void)
1362 {
1363         update_cpu_capabilities(arm64_features, "detected feature:");
1364         enable_cpu_capabilities(arm64_features);
1365 }
1366
1367 DEFINE_STATIC_KEY_FALSE(arm64_const_caps_ready);
1368 EXPORT_SYMBOL(arm64_const_caps_ready);
1369
1370 static void __init mark_const_caps_ready(void)
1371 {
1372         static_branch_enable(&arm64_const_caps_ready);
1373 }
1374
1375 extern const struct arm64_cpu_capabilities arm64_errata[];
1376
1377 bool this_cpu_has_cap(unsigned int cap)
1378 {
1379         return (__this_cpu_has_cap(arm64_features, cap) ||
1380                 __this_cpu_has_cap(arm64_errata, cap));
1381 }
1382
1383 void __init setup_cpu_features(void)
1384 {
1385         u32 cwg;
1386         int cls;
1387
1388         /* Set the CPU feature capabilies */
1389         setup_feature_capabilities();
1390         enable_errata_workarounds();
1391         mark_const_caps_ready();
1392         setup_elf_hwcaps(arm64_elf_hwcaps);
1393
1394         if (system_supports_32bit_el0())
1395                 setup_elf_hwcaps(compat_elf_hwcaps);
1396
1397         sve_setup();
1398
1399         /* Advertise that we have computed the system capabilities */
1400         set_sys_caps_initialised();
1401
1402         /*
1403          * Check for sane CTR_EL0.CWG value.
1404          */
1405         cwg = cache_type_cwg();
1406         cls = cache_line_size();
1407         if (!cwg)
1408                 pr_warn("No Cache Writeback Granule information, assuming cache line size %d\n",
1409                         cls);
1410         if (L1_CACHE_BYTES < cls)
1411                 pr_warn("L1_CACHE_BYTES smaller than the Cache Writeback Granule (%d < %d)\n",
1412                         L1_CACHE_BYTES, cls);
1413 }
1414
1415 static bool __maybe_unused
1416 cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry, int __unused)
1417 {
1418         return (cpus_have_const_cap(ARM64_HAS_PAN) && !cpus_have_const_cap(ARM64_HAS_UAO));
1419 }
1420
1421 /*
1422  * We emulate only the following system register space.
1423  * Op0 = 0x3, CRn = 0x0, Op1 = 0x0, CRm = [0, 4 - 7]
1424  * See Table C5-6 System instruction encodings for System register accesses,
1425  * ARMv8 ARM(ARM DDI 0487A.f) for more details.
1426  */
1427 static inline bool __attribute_const__ is_emulated(u32 id)
1428 {
1429         return (sys_reg_Op0(id) == 0x3 &&
1430                 sys_reg_CRn(id) == 0x0 &&
1431                 sys_reg_Op1(id) == 0x0 &&
1432                 (sys_reg_CRm(id) == 0 ||
1433                  ((sys_reg_CRm(id) >= 4) && (sys_reg_CRm(id) <= 7))));
1434 }
1435
1436 /*
1437  * With CRm == 0, reg should be one of :
1438  * MIDR_EL1, MPIDR_EL1 or REVIDR_EL1.
1439  */
1440 static inline int emulate_id_reg(u32 id, u64 *valp)
1441 {
1442         switch (id) {
1443         case SYS_MIDR_EL1:
1444                 *valp = read_cpuid_id();
1445                 break;
1446         case SYS_MPIDR_EL1:
1447                 *valp = SYS_MPIDR_SAFE_VAL;
1448                 break;
1449         case SYS_REVIDR_EL1:
1450                 /* IMPLEMENTATION DEFINED values are emulated with 0 */
1451                 *valp = 0;
1452                 break;
1453         default:
1454                 return -EINVAL;
1455         }
1456
1457         return 0;
1458 }
1459
1460 static int emulate_sys_reg(u32 id, u64 *valp)
1461 {
1462         struct arm64_ftr_reg *regp;
1463
1464         if (!is_emulated(id))
1465                 return -EINVAL;
1466
1467         if (sys_reg_CRm(id) == 0)
1468                 return emulate_id_reg(id, valp);
1469
1470         regp = get_arm64_ftr_reg(id);
1471         if (regp)
1472                 *valp = arm64_ftr_reg_user_value(regp);
1473         else
1474                 /*
1475                  * The untracked registers are either IMPLEMENTATION DEFINED
1476                  * (e.g, ID_AFR0_EL1) or reserved RAZ.
1477                  */
1478                 *valp = 0;
1479         return 0;
1480 }
1481
1482 static int emulate_mrs(struct pt_regs *regs, u32 insn)
1483 {
1484         int rc;
1485         u32 sys_reg, dst;
1486         u64 val;
1487
1488         /*
1489          * sys_reg values are defined as used in mrs/msr instruction.
1490          * shift the imm value to get the encoding.
1491          */
1492         sys_reg = (u32)aarch64_insn_decode_immediate(AARCH64_INSN_IMM_16, insn) << 5;
1493         rc = emulate_sys_reg(sys_reg, &val);
1494         if (!rc) {
1495                 dst = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RT, insn);
1496                 pt_regs_write_reg(regs, dst, val);
1497                 arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);
1498         }
1499
1500         return rc;
1501 }
1502
1503 static struct undef_hook mrs_hook = {
1504         .instr_mask = 0xfff00000,
1505         .instr_val  = 0xd5300000,
1506         .pstate_mask = COMPAT_PSR_MODE_MASK,
1507         .pstate_val = PSR_MODE_EL0t,
1508         .fn = emulate_mrs,
1509 };
1510
1511 static int __init enable_mrs_emulation(void)
1512 {
1513         register_undef_hook(&mrs_hook);
1514         return 0;
1515 }
1516
1517 core_initcall(enable_mrs_emulation);
1518
1519 int cpu_clear_disr(void *__unused)
1520 {
1521         /* Firmware may have left a deferred SError in this register. */
1522         write_sysreg_s(0, SYS_DISR_EL1);
1523
1524         return 0;
1525 }