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/sort.h>
  23 #include <linux/types.h>
  24 #include <asm/cpu.h>
  25 #include <asm/cpufeature.h>
  26 #include <asm/cpu_ops.h>
  27 #include <asm/processor.h>
  28 #include <asm/sysreg.h>
  29
  30 unsigned long elf_hwcap __read_mostly;
  31 EXPORT_SYMBOL_GPL(elf_hwcap);
  32
  33 #ifdef CONFIG_COMPAT
  34 #define COMPAT_ELF_HWCAP_DEFAULT        \
  35                                 (COMPAT_HWCAP_HALF|COMPAT_HWCAP_THUMB|\
  36                                  COMPAT_HWCAP_FAST_MULT|COMPAT_HWCAP_EDSP|\
  37                                  COMPAT_HWCAP_TLS|COMPAT_HWCAP_VFP|\
  38                                  COMPAT_HWCAP_VFPv3|COMPAT_HWCAP_VFPv4|\
  39                                  COMPAT_HWCAP_NEON|COMPAT_HWCAP_IDIV|\
  40                                  COMPAT_HWCAP_LPAE)
  41 unsigned int compat_elf_hwcap __read_mostly = COMPAT_ELF_HWCAP_DEFAULT;
  42 unsigned int compat_elf_hwcap2 __read_mostly;
  43 #endif
  44
  45 DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS);
  46
  47 #define ARM64_FTR_BITS(STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
  48         {                                               \
  49                 .strict = STRICT,                       \
  50                 .type = TYPE,                           \
  51                 .shift = SHIFT,                         \
  52                 .width = WIDTH,                         \
  53                 .safe_val = SAFE_VAL,                   \
  54         }
  55
  56 #define ARM64_FTR_END                                   \
  57         {                                               \
  58                 .width = 0,                             \
  59         }
  60
  61 static struct arm64_ftr_bits ftr_id_aa64isar0[] = {
  62         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 32, 32, 0),
  63         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64ISAR0_RDM_SHIFT, 4, 0),
  64         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 24, 4, 0),
  65         ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_ATOMICS_SHIFT, 4, 0),
  66         ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_CRC32_SHIFT, 4, 0),
  67         ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA2_SHIFT, 4, 0),
  68         ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA1_SHIFT, 4, 0),
  69         ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_AES_SHIFT, 4, 0),
  70         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 4, 0), /* RAZ */
  71         ARM64_FTR_END,
  72 };
  73
  74 static struct arm64_ftr_bits ftr_id_aa64pfr0[] = {
  75         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 32, 32, 0),
  76         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 28, 4, 0),
  77         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64PFR0_GIC_SHIFT, 4, 0),
  78         ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_ASIMD_SHIFT, 4, ID_AA64PFR0_ASIMD_NI),
  79         ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_FP_SHIFT, 4, ID_AA64PFR0_FP_NI),
  80         /* Linux doesn't care about the EL3 */
  81         ARM64_FTR_BITS(FTR_NONSTRICT, FTR_EXACT, ID_AA64PFR0_EL3_SHIFT, 4, 0),
  82         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64PFR0_EL2_SHIFT, 4, 0),
  83         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64PFR0_EL1_SHIFT, 4, ID_AA64PFR0_EL1_64BIT_ONLY),
  84         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64PFR0_EL0_SHIFT, 4, ID_AA64PFR0_EL0_64BIT_ONLY),
  85         ARM64_FTR_END,
  86 };
  87
  88 static struct arm64_ftr_bits ftr_id_aa64mmfr0[] = {
  89         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 32, 32, 0),
  90         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN4_SHIFT, 4, ID_AA64MMFR0_TGRAN4_NI),
  91         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN64_SHIFT, 4, ID_AA64MMFR0_TGRAN64_NI),
  92         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN16_SHIFT, 4, ID_AA64MMFR0_TGRAN16_NI),
  93         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_BIGENDEL0_SHIFT, 4, 0),
  94         /* Linux shouldn't care about secure memory */
  95         ARM64_FTR_BITS(FTR_NONSTRICT, FTR_EXACT, ID_AA64MMFR0_SNSMEM_SHIFT, 4, 0),
  96         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_BIGENDEL_SHIFT, 4, 0),
  97         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_ASID_SHIFT, 4, 0),
  98         /*
  99          * Differing PARange is fine as long as all peripherals and memory are mapped
 100          * within the minimum PARange of all CPUs
 101          */
 102         ARM64_FTR_BITS(FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_PARANGE_SHIFT, 4, 0),
 103         ARM64_FTR_END,
 104 };
 105
 106 static struct arm64_ftr_bits ftr_id_aa64mmfr1[] = {
 107         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 32, 32, 0),
 108         ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_PAN_SHIFT, 4, 0),
 109         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_LOR_SHIFT, 4, 0),
 110         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_HPD_SHIFT, 4, 0),
 111         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_VHE_SHIFT, 4, 0),
 112         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_VMIDBITS_SHIFT, 4, 0),
 113         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_HADBS_SHIFT, 4, 0),
 114         ARM64_FTR_END,
 115 };
 116
 117 static struct arm64_ftr_bits ftr_ctr[] = {
 118         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 31, 1, 1),        /* RAO */
 119         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 28, 3, 0),
 120         ARM64_FTR_BITS(FTR_STRICT, FTR_HIGHER_SAFE, 24, 4, 0),  /* CWG */
 121         ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0),   /* ERG */
 122         ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 1),   /* DminLine */
 123         /*
 124          * Linux can handle differing I-cache policies. Userspace JITs will
 125          * make use of *minLine
 126          */
 127         ARM64_FTR_BITS(FTR_NONSTRICT, FTR_EXACT, 14, 2, 0),     /* L1Ip */
 128         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 10, 0),        /* RAZ */
 129         ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),    /* IminLine */
 130         ARM64_FTR_END,
 131 };
 132
 133 static struct arm64_ftr_bits ftr_id_mmfr0[] = {
 134         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 28, 4, 0),        /* InnerShr */
 135         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 24, 4, 0),        /* FCSE */
 136         ARM64_FTR_BITS(FTR_NONSTRICT, FTR_LOWER_SAFE, 20, 4, 0),        /* AuxReg */
 137         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 16, 4, 0),        /* TCM */
 138         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 12, 4, 0),        /* ShareLvl */
 139         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 8, 4, 0), /* OuterShr */
 140         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 4, 0), /* PMSA */
 141         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 4, 0), /* VMSA */
 142         ARM64_FTR_END,
 143 };
 144
 145 static struct arm64_ftr_bits ftr_id_aa64dfr0[] = {
 146         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 32, 32, 0),
 147         ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_CTX_CMPS_SHIFT, 4, 0),
 148         ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_WRPS_SHIFT, 4, 0),
 149         ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_BRPS_SHIFT, 4, 0),
 150         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64DFR0_PMUVER_SHIFT, 4, 0),
 151         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64DFR0_TRACEVER_SHIFT, 4, 0),
 152         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64DFR0_DEBUGVER_SHIFT, 4, 0x6),
 153         ARM64_FTR_END,
 154 };
 155
 156 static struct arm64_ftr_bits ftr_mvfr2[] = {
 157         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 8, 24, 0),        /* RAZ */
 158         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 4, 0),         /* FPMisc */
 159         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 4, 0),         /* SIMDMisc */
 160         ARM64_FTR_END,
 161 };
 162
 163 static struct arm64_ftr_bits ftr_dczid[] = {
 164         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 5, 27, 0),        /* RAZ */
 165         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 1, 1),         /* DZP */
 166         ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),    /* BS */
 167         ARM64_FTR_END,
 168 };
 169
 170
 171 static struct arm64_ftr_bits ftr_id_isar5[] = {
 172         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_RDM_SHIFT, 4, 0),
 173         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 20, 4, 0),        /* RAZ */
 174         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_CRC32_SHIFT, 4, 0),
 175         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_SHA2_SHIFT, 4, 0),
 176         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_SHA1_SHIFT, 4, 0),
 177         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_AES_SHIFT, 4, 0),
 178         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_SEVL_SHIFT, 4, 0),
 179         ARM64_FTR_END,
 180 };
 181
 182 static struct arm64_ftr_bits ftr_id_mmfr4[] = {
 183         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 8, 24, 0),        /* RAZ */
 184         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 4, 0),         /* ac2 */
 185         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 4, 0),         /* RAZ */
 186         ARM64_FTR_END,
 187 };
 188
 189 static struct arm64_ftr_bits ftr_id_pfr0[] = {
 190         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 16, 16, 0),       /* RAZ */
 191         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 12, 4, 0),        /* State3 */
 192         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 8, 4, 0),         /* State2 */
 193         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 4, 0),         /* State1 */
 194         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 4, 0),         /* State0 */
 195         ARM64_FTR_END,
 196 };
 197
 198 /*
 199  * Common ftr bits for a 32bit register with all hidden, strict
 200  * attributes, with 4bit feature fields and a default safe value of
 201  * 0. Covers the following 32bit registers:
 202  * id_isar[0-4], id_mmfr[1-3], id_pfr1, mvfr[0-1]
 203  */
 204 static struct arm64_ftr_bits ftr_generic_32bits[] = {
 205         ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0),
 206         ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0),
 207         ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0),
 208         ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0),
 209         ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),
 210         ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0),
 211         ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),
 212         ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),
 213         ARM64_FTR_END,
 214 };
 215
 216 static struct arm64_ftr_bits ftr_generic[] = {
 217         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 64, 0),
 218         ARM64_FTR_END,
 219 };
 220
 221 static struct arm64_ftr_bits ftr_generic32[] = {
 222         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 32, 0),
 223         ARM64_FTR_END,
 224 };
 225
 226 static struct arm64_ftr_bits ftr_aa64raz[] = {
 227         ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 64, 0),
 228         ARM64_FTR_END,
 229 };
 230
 231 #define ARM64_FTR_REG(id, table)                \
 232         {                                       \
 233                 .sys_id = id,                   \
 234                 .name = #id,                    \
 235                 .ftr_bits = &((table)[0]),      \
 236         }
 237
 238 static struct arm64_ftr_reg arm64_ftr_regs[] = {
 239
 240         /* Op1 = 0, CRn = 0, CRm = 1 */
 241         ARM64_FTR_REG(SYS_ID_PFR0_EL1, ftr_id_pfr0),
 242         ARM64_FTR_REG(SYS_ID_PFR1_EL1, ftr_generic_32bits),
 243         ARM64_FTR_REG(SYS_ID_DFR0_EL1, ftr_generic_32bits),
 244         ARM64_FTR_REG(SYS_ID_MMFR0_EL1, ftr_id_mmfr0),
 245         ARM64_FTR_REG(SYS_ID_MMFR1_EL1, ftr_generic_32bits),
 246         ARM64_FTR_REG(SYS_ID_MMFR2_EL1, ftr_generic_32bits),
 247         ARM64_FTR_REG(SYS_ID_MMFR3_EL1, ftr_generic_32bits),
 248
 249         /* Op1 = 0, CRn = 0, CRm = 2 */
 250         ARM64_FTR_REG(SYS_ID_ISAR0_EL1, ftr_generic_32bits),
 251         ARM64_FTR_REG(SYS_ID_ISAR1_EL1, ftr_generic_32bits),
 252         ARM64_FTR_REG(SYS_ID_ISAR2_EL1, ftr_generic_32bits),
 253         ARM64_FTR_REG(SYS_ID_ISAR3_EL1, ftr_generic_32bits),
 254         ARM64_FTR_REG(SYS_ID_ISAR4_EL1, ftr_generic_32bits),
 255         ARM64_FTR_REG(SYS_ID_ISAR5_EL1, ftr_id_isar5),
 256         ARM64_FTR_REG(SYS_ID_MMFR4_EL1, ftr_id_mmfr4),
 257
 258         /* Op1 = 0, CRn = 0, CRm = 3 */
 259         ARM64_FTR_REG(SYS_MVFR0_EL1, ftr_generic_32bits),
 260         ARM64_FTR_REG(SYS_MVFR1_EL1, ftr_generic_32bits),
 261         ARM64_FTR_REG(SYS_MVFR2_EL1, ftr_mvfr2),
 262
 263         /* Op1 = 0, CRn = 0, CRm = 4 */
 264         ARM64_FTR_REG(SYS_ID_AA64PFR0_EL1, ftr_id_aa64pfr0),
 265         ARM64_FTR_REG(SYS_ID_AA64PFR1_EL1, ftr_aa64raz),
 266
 267         /* Op1 = 0, CRn = 0, CRm = 5 */
 268         ARM64_FTR_REG(SYS_ID_AA64DFR0_EL1, ftr_id_aa64dfr0),
 269         ARM64_FTR_REG(SYS_ID_AA64DFR1_EL1, ftr_generic),
 270
 271         /* Op1 = 0, CRn = 0, CRm = 6 */
 272         ARM64_FTR_REG(SYS_ID_AA64ISAR0_EL1, ftr_id_aa64isar0),
 273         ARM64_FTR_REG(SYS_ID_AA64ISAR1_EL1, ftr_aa64raz),
 274
 275         /* Op1 = 0, CRn = 0, CRm = 7 */
 276         ARM64_FTR_REG(SYS_ID_AA64MMFR0_EL1, ftr_id_aa64mmfr0),
 277         ARM64_FTR_REG(SYS_ID_AA64MMFR1_EL1, ftr_id_aa64mmfr1),
 278
 279         /* Op1 = 3, CRn = 0, CRm = 0 */
 280         ARM64_FTR_REG(SYS_CTR_EL0, ftr_ctr),
 281         ARM64_FTR_REG(SYS_DCZID_EL0, ftr_dczid),
 282
 283         /* Op1 = 3, CRn = 14, CRm = 0 */
 284         ARM64_FTR_REG(SYS_CNTFRQ_EL0, ftr_generic32),
 285 };
 286
 287 static int search_cmp_ftr_reg(const void *id, const void *regp)
 288 {
 289         return (int)(unsigned long)id - (int)((const struct arm64_ftr_reg *)regp)->sys_id;
 290 }
 291
 292 /*
 293  * get_arm64_ftr_reg - Lookup a feature register entry using its
 294  * sys_reg() encoding. With the array arm64_ftr_regs sorted in the
 295  * ascending order of sys_id , we use binary search to find a matching
 296  * entry.
 297  *
 298  * returns - Upon success,  matching ftr_reg entry for id.
 299  *         - NULL on failure. It is upto the caller to decide
 300  *           the impact of a failure.
 301  */
 302 static struct arm64_ftr_reg *get_arm64_ftr_reg(u32 sys_id)
 303 {
 304         return bsearch((const void *)(unsigned long)sys_id,
 305                         arm64_ftr_regs,
 306                         ARRAY_SIZE(arm64_ftr_regs),
 307                         sizeof(arm64_ftr_regs[0]),
 308                         search_cmp_ftr_reg);
 309 }
 310
 311 static u64 arm64_ftr_set_value(struct arm64_ftr_bits *ftrp, s64 reg, s64 ftr_val)
 312 {
 313         u64 mask = arm64_ftr_mask(ftrp);
 314
 315         reg &= ~mask;
 316         reg |= (ftr_val << ftrp->shift) & mask;
 317         return reg;
 318 }
 319
 320 static s64 arm64_ftr_safe_value(struct arm64_ftr_bits *ftrp, s64 new, s64 cur)
 321 {
 322         s64 ret = 0;
 323
 324         switch (ftrp->type) {
 325         case FTR_EXACT:
 326                 ret = ftrp->safe_val;
 327                 break;
 328         case FTR_LOWER_SAFE:
 329                 ret = new < cur ? new : cur;
 330                 break;
 331         case FTR_HIGHER_SAFE:
 332                 ret = new > cur ? new : cur;
 333                 break;
 334         default:
 335                 BUG();
 336         }
 337
 338         return ret;
 339 }
 340
 341 static int __init sort_cmp_ftr_regs(const void *a, const void *b)
 342 {
 343         return ((const struct arm64_ftr_reg *)a)->sys_id -
 344                  ((const struct arm64_ftr_reg *)b)->sys_id;
 345 }
 346
 347 static void __init swap_ftr_regs(void *a, void *b, int size)
 348 {
 349         struct arm64_ftr_reg tmp = *(struct arm64_ftr_reg *)a;
 350         *(struct arm64_ftr_reg *)a = *(struct arm64_ftr_reg *)b;
 351         *(struct arm64_ftr_reg *)b = tmp;
 352 }
 353
 354 static void __init sort_ftr_regs(void)
 355 {
 356         /* Keep the array sorted so that we can do the binary search */
 357         sort(arm64_ftr_regs,
 358                 ARRAY_SIZE(arm64_ftr_regs),
 359                 sizeof(arm64_ftr_regs[0]),
 360                 sort_cmp_ftr_regs,
 361                 swap_ftr_regs);
 362 }
 363
 364 /*
 365  * Initialise the CPU feature register from Boot CPU values.
 366  * Also initiliases the strict_mask for the register.
 367  */
 368 static void __init init_cpu_ftr_reg(u32 sys_reg, u64 new)
 369 {
 370         u64 val = 0;
 371         u64 strict_mask = ~0x0ULL;
 372         struct arm64_ftr_bits *ftrp;
 373         struct arm64_ftr_reg *reg = get_arm64_ftr_reg(sys_reg);
 374
 375         BUG_ON(!reg);
 376
 377         for (ftrp  = reg->ftr_bits; ftrp->width; ftrp++) {
 378                 s64 ftr_new = arm64_ftr_value(ftrp, new);
 379
 380                 val = arm64_ftr_set_value(ftrp, val, ftr_new);
 381                 if (!ftrp->strict)
 382                         strict_mask &= ~arm64_ftr_mask(ftrp);
 383         }
 384         reg->sys_val = val;
 385         reg->strict_mask = strict_mask;
 386 }
 387
 388 void __init init_cpu_features(struct cpuinfo_arm64 *info)
 389 {
 390         /* Before we start using the tables, make sure it is sorted */
 391         sort_ftr_regs();
 392
 393         init_cpu_ftr_reg(SYS_CTR_EL0, info->reg_ctr);
 394         init_cpu_ftr_reg(SYS_DCZID_EL0, info->reg_dczid);
 395         init_cpu_ftr_reg(SYS_CNTFRQ_EL0, info->reg_cntfrq);
 396         init_cpu_ftr_reg(SYS_ID_AA64DFR0_EL1, info->reg_id_aa64dfr0);
 397         init_cpu_ftr_reg(SYS_ID_AA64DFR1_EL1, info->reg_id_aa64dfr1);
 398         init_cpu_ftr_reg(SYS_ID_AA64ISAR0_EL1, info->reg_id_aa64isar0);
 399         init_cpu_ftr_reg(SYS_ID_AA64ISAR1_EL1, info->reg_id_aa64isar1);
 400         init_cpu_ftr_reg(SYS_ID_AA64MMFR0_EL1, info->reg_id_aa64mmfr0);
 401         init_cpu_ftr_reg(SYS_ID_AA64MMFR1_EL1, info->reg_id_aa64mmfr1);
 402         init_cpu_ftr_reg(SYS_ID_AA64PFR0_EL1, info->reg_id_aa64pfr0);
 403         init_cpu_ftr_reg(SYS_ID_AA64PFR1_EL1, info->reg_id_aa64pfr1);
 404         init_cpu_ftr_reg(SYS_ID_DFR0_EL1, info->reg_id_dfr0);
 405         init_cpu_ftr_reg(SYS_ID_ISAR0_EL1, info->reg_id_isar0);
 406         init_cpu_ftr_reg(SYS_ID_ISAR1_EL1, info->reg_id_isar1);
 407         init_cpu_ftr_reg(SYS_ID_ISAR2_EL1, info->reg_id_isar2);
 408         init_cpu_ftr_reg(SYS_ID_ISAR3_EL1, info->reg_id_isar3);
 409         init_cpu_ftr_reg(SYS_ID_ISAR4_EL1, info->reg_id_isar4);
 410         init_cpu_ftr_reg(SYS_ID_ISAR5_EL1, info->reg_id_isar5);
 411         init_cpu_ftr_reg(SYS_ID_MMFR0_EL1, info->reg_id_mmfr0);
 412         init_cpu_ftr_reg(SYS_ID_MMFR1_EL1, info->reg_id_mmfr1);
 413         init_cpu_ftr_reg(SYS_ID_MMFR2_EL1, info->reg_id_mmfr2);
 414         init_cpu_ftr_reg(SYS_ID_MMFR3_EL1, info->reg_id_mmfr3);
 415         init_cpu_ftr_reg(SYS_ID_PFR0_EL1, info->reg_id_pfr0);
 416         init_cpu_ftr_reg(SYS_ID_PFR1_EL1, info->reg_id_pfr1);
 417         init_cpu_ftr_reg(SYS_MVFR0_EL1, info->reg_mvfr0);
 418         init_cpu_ftr_reg(SYS_MVFR1_EL1, info->reg_mvfr1);
 419         init_cpu_ftr_reg(SYS_MVFR2_EL1, info->reg_mvfr2);
 420 }
 421
 422 static void update_cpu_ftr_reg(struct arm64_ftr_reg *reg, u64 new)
 423 {
 424         struct arm64_ftr_bits *ftrp;
 425
 426         for (ftrp = reg->ftr_bits; ftrp->width; ftrp++) {
 427                 s64 ftr_cur = arm64_ftr_value(ftrp, reg->sys_val);
 428                 s64 ftr_new = arm64_ftr_value(ftrp, new);
 429
 430                 if (ftr_cur == ftr_new)
 431                         continue;
 432                 /* Find a safe value */
 433                 ftr_new = arm64_ftr_safe_value(ftrp, ftr_new, ftr_cur);
 434                 reg->sys_val = arm64_ftr_set_value(ftrp, reg->sys_val, ftr_new);
 435         }
 436
 437 }
 438
 439 static int check_update_ftr_reg(u32 sys_id, int cpu, u64 val, u64 boot)
 440 {
 441         struct arm64_ftr_reg *regp = get_arm64_ftr_reg(sys_id);
 442
 443         BUG_ON(!regp);
 444         update_cpu_ftr_reg(regp, val);
 445         if ((boot & regp->strict_mask) == (val & regp->strict_mask))
 446                 return 0;
 447         pr_warn("SANITY CHECK: Unexpected variation in %s. Boot CPU: %#016llx, CPU%d: %#016llx\n",
 448                         regp->name, boot, cpu, val);
 449         return 1;
 450 }
 451
 452 /*
 453  * Update system wide CPU feature registers with the values from a
 454  * non-boot CPU. Also performs SANITY checks to make sure that there
 455  * aren't any insane variations from that of the boot CPU.
 456  */
 457 void update_cpu_features(int cpu,
 458                          struct cpuinfo_arm64 *info,
 459                          struct cpuinfo_arm64 *boot)
 460 {
 461         int taint = 0;
 462
 463         /*
 464          * The kernel can handle differing I-cache policies, but otherwise
 465          * caches should look identical. Userspace JITs will make use of
 466          * *minLine.
 467          */
 468         taint |= check_update_ftr_reg(SYS_CTR_EL0, cpu,
 469                                       info->reg_ctr, boot->reg_ctr);
 470
 471         /*
 472          * Userspace may perform DC ZVA instructions. Mismatched block sizes
 473          * could result in too much or too little memory being zeroed if a
 474          * process is preempted and migrated between CPUs.
 475          */
 476         taint |= check_update_ftr_reg(SYS_DCZID_EL0, cpu,
 477                                       info->reg_dczid, boot->reg_dczid);
 478
 479         /* If different, timekeeping will be broken (especially with KVM) */
 480         taint |= check_update_ftr_reg(SYS_CNTFRQ_EL0, cpu,
 481                                       info->reg_cntfrq, boot->reg_cntfrq);
 482
 483         /*
 484          * The kernel uses self-hosted debug features and expects CPUs to
 485          * support identical debug features. We presently need CTX_CMPs, WRPs,
 486          * and BRPs to be identical.
 487          * ID_AA64DFR1 is currently RES0.
 488          */
 489         taint |= check_update_ftr_reg(SYS_ID_AA64DFR0_EL1, cpu,
 490                                       info->reg_id_aa64dfr0, boot->reg_id_aa64dfr0);
 491         taint |= check_update_ftr_reg(SYS_ID_AA64DFR1_EL1, cpu,
 492                                       info->reg_id_aa64dfr1, boot->reg_id_aa64dfr1);
 493         /*
 494          * Even in big.LITTLE, processors should be identical instruction-set
 495          * wise.
 496          */
 497         taint |= check_update_ftr_reg(SYS_ID_AA64ISAR0_EL1, cpu,
 498                                       info->reg_id_aa64isar0, boot->reg_id_aa64isar0);
 499         taint |= check_update_ftr_reg(SYS_ID_AA64ISAR1_EL1, cpu,
 500                                       info->reg_id_aa64isar1, boot->reg_id_aa64isar1);
 501
 502         /*
 503          * Differing PARange support is fine as long as all peripherals and
 504          * memory are mapped within the minimum PARange of all CPUs.
 505          * Linux should not care about secure memory.
 506          */
 507         taint |= check_update_ftr_reg(SYS_ID_AA64MMFR0_EL1, cpu,
 508                                       info->reg_id_aa64mmfr0, boot->reg_id_aa64mmfr0);
 509         taint |= check_update_ftr_reg(SYS_ID_AA64MMFR1_EL1, cpu,
 510                                       info->reg_id_aa64mmfr1, boot->reg_id_aa64mmfr1);
 511
 512         /*
 513          * EL3 is not our concern.
 514          * ID_AA64PFR1 is currently RES0.
 515          */
 516         taint |= check_update_ftr_reg(SYS_ID_AA64PFR0_EL1, cpu,
 517                                       info->reg_id_aa64pfr0, boot->reg_id_aa64pfr0);
 518         taint |= check_update_ftr_reg(SYS_ID_AA64PFR1_EL1, cpu,
 519                                       info->reg_id_aa64pfr1, boot->reg_id_aa64pfr1);
 520
 521         /*
 522          * If we have AArch32, we care about 32-bit features for compat. These
 523          * registers should be RES0 otherwise.
 524          */
 525         taint |= check_update_ftr_reg(SYS_ID_DFR0_EL1, cpu,
 526                                         info->reg_id_dfr0, boot->reg_id_dfr0);
 527         taint |= check_update_ftr_reg(SYS_ID_ISAR0_EL1, cpu,
 528                                         info->reg_id_isar0, boot->reg_id_isar0);
 529         taint |= check_update_ftr_reg(SYS_ID_ISAR1_EL1, cpu,
 530                                         info->reg_id_isar1, boot->reg_id_isar1);
 531         taint |= check_update_ftr_reg(SYS_ID_ISAR2_EL1, cpu,
 532                                         info->reg_id_isar2, boot->reg_id_isar2);
 533         taint |= check_update_ftr_reg(SYS_ID_ISAR3_EL1, cpu,
 534                                         info->reg_id_isar3, boot->reg_id_isar3);
 535         taint |= check_update_ftr_reg(SYS_ID_ISAR4_EL1, cpu,
 536                                         info->reg_id_isar4, boot->reg_id_isar4);
 537         taint |= check_update_ftr_reg(SYS_ID_ISAR5_EL1, cpu,
 538                                         info->reg_id_isar5, boot->reg_id_isar5);
 539
 540         /*
 541          * Regardless of the value of the AuxReg field, the AIFSR, ADFSR, and
 542          * ACTLR formats could differ across CPUs and therefore would have to
 543          * be trapped for virtualization anyway.
 544          */
 545         taint |= check_update_ftr_reg(SYS_ID_MMFR0_EL1, cpu,
 546                                         info->reg_id_mmfr0, boot->reg_id_mmfr0);
 547         taint |= check_update_ftr_reg(SYS_ID_MMFR1_EL1, cpu,
 548                                         info->reg_id_mmfr1, boot->reg_id_mmfr1);
 549         taint |= check_update_ftr_reg(SYS_ID_MMFR2_EL1, cpu,
 550                                         info->reg_id_mmfr2, boot->reg_id_mmfr2);
 551         taint |= check_update_ftr_reg(SYS_ID_MMFR3_EL1, cpu,
 552                                         info->reg_id_mmfr3, boot->reg_id_mmfr3);
 553         taint |= check_update_ftr_reg(SYS_ID_PFR0_EL1, cpu,
 554                                         info->reg_id_pfr0, boot->reg_id_pfr0);
 555         taint |= check_update_ftr_reg(SYS_ID_PFR1_EL1, cpu,
 556                                         info->reg_id_pfr1, boot->reg_id_pfr1);
 557         taint |= check_update_ftr_reg(SYS_MVFR0_EL1, cpu,
 558                                         info->reg_mvfr0, boot->reg_mvfr0);
 559         taint |= check_update_ftr_reg(SYS_MVFR1_EL1, cpu,
 560                                         info->reg_mvfr1, boot->reg_mvfr1);
 561         taint |= check_update_ftr_reg(SYS_MVFR2_EL1, cpu,
 562                                         info->reg_mvfr2, boot->reg_mvfr2);
 563
 564         /*
 565          * Mismatched CPU features are a recipe for disaster. Don't even
 566          * pretend to support them.
 567          */
 568         WARN_TAINT_ONCE(taint, TAINT_CPU_OUT_OF_SPEC,
 569                         "Unsupported CPU feature variation.\n");
 570 }
 571
 572 u64 read_system_reg(u32 id)
 573 {
 574         struct arm64_ftr_reg *regp = get_arm64_ftr_reg(id);
 575
 576         /* We shouldn't get a request for an unsupported register */
 577         BUG_ON(!regp);
 578         return regp->sys_val;
 579 }
 580
 581 static bool
 582 feature_matches(u64 reg, const struct arm64_cpu_capabilities *entry)
 583 {
 584         int val = cpuid_feature_extract_field(reg, entry->field_pos);
 585
 586         return val >= entry->min_field_value;
 587 }
 588
 589 static bool
 590 has_cpuid_feature(const struct arm64_cpu_capabilities *entry)
 591 {
 592         u64 val;
 593
 594         val = read_system_reg(entry->sys_reg);
 595         return feature_matches(val, entry);
 596 }
 597
 598 static const struct arm64_cpu_capabilities arm64_features[] = {
 599         {
 600                 .desc = "GIC system register CPU interface",
 601                 .capability = ARM64_HAS_SYSREG_GIC_CPUIF,
 602                 .matches = has_cpuid_feature,
 603                 .sys_reg = SYS_ID_AA64PFR0_EL1,
 604                 .field_pos = ID_AA64PFR0_GIC_SHIFT,
 605                 .min_field_value = 1,
 606         },
 607 #ifdef CONFIG_ARM64_PAN
 608         {
 609                 .desc = "Privileged Access Never",
 610                 .capability = ARM64_HAS_PAN,
 611                 .matches = has_cpuid_feature,
 612                 .sys_reg = SYS_ID_AA64MMFR1_EL1,
 613                 .field_pos = ID_AA64MMFR1_PAN_SHIFT,
 614                 .min_field_value = 1,
 615                 .enable = cpu_enable_pan,
 616         },
 617 #endif /* CONFIG_ARM64_PAN */
 618 #if defined(CONFIG_AS_LSE) && defined(CONFIG_ARM64_LSE_ATOMICS)
 619         {
 620                 .desc = "LSE atomic instructions",
 621                 .capability = ARM64_HAS_LSE_ATOMICS,
 622                 .matches = has_cpuid_feature,
 623                 .sys_reg = SYS_ID_AA64ISAR0_EL1,
 624                 .field_pos = ID_AA64ISAR0_ATOMICS_SHIFT,
 625                 .min_field_value = 2,
 626         },
 627 #endif /* CONFIG_AS_LSE && CONFIG_ARM64_LSE_ATOMICS */
 628         {},
 629 };
 630
 631 #define HWCAP_CAP(reg, field, min_value, type, cap)             \
 632         {                                                       \
 633                 .desc = #cap,                                   \
 634                 .matches = has_cpuid_feature,                   \
 635                 .sys_reg = reg,                                 \
 636                 .field_pos = field,                             \
 637                 .min_field_value = min_value,                   \
 638                 .hwcap_type = type,                             \
 639                 .hwcap = cap,                                   \
 640         }
 641
 642 static const struct arm64_cpu_capabilities arm64_hwcaps[] = {
 643         HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_AES_SHIFT, 2, CAP_HWCAP, HWCAP_PMULL),
 644         HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_AES_SHIFT, 1, CAP_HWCAP, HWCAP_AES),
 645         HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA1_SHIFT, 1, CAP_HWCAP, HWCAP_SHA1),
 646         HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA2_SHIFT, 1, CAP_HWCAP, HWCAP_SHA2),
 647         HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_CRC32_SHIFT, 1, CAP_HWCAP, HWCAP_CRC32),
 648         HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_ATOMICS_SHIFT, 2, CAP_HWCAP, HWCAP_ATOMICS),
 649 #ifdef CONFIG_COMPAT
 650         HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, 2, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_PMULL),
 651         HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_AES),
 652         HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA1_SHIFT, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA1),
 653         HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA2_SHIFT, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA2),
 654         HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_CRC32_SHIFT, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_CRC32),
 655 #endif
 656         {},
 657 };
 658
 659 static void cap_set_hwcap(const struct arm64_cpu_capabilities *cap)
 660 {
 661         switch (cap->hwcap_type) {
 662         case CAP_HWCAP:
 663                 elf_hwcap |= cap->hwcap;
 664                 break;
 665 #ifdef CONFIG_COMPAT
 666         case CAP_COMPAT_HWCAP:
 667                 compat_elf_hwcap |= (u32)cap->hwcap;
 668                 break;
 669         case CAP_COMPAT_HWCAP2:
 670                 compat_elf_hwcap2 |= (u32)cap->hwcap;
 671                 break;
 672 #endif
 673         default:
 674                 WARN_ON(1);
 675                 break;
 676         }
 677 }
 678
 679 /* Check if we have a particular HWCAP enabled */
 680 static bool cpus_have_hwcap(const struct arm64_cpu_capabilities *cap)
 681 {
 682         bool rc;
 683
 684         switch (cap->hwcap_type) {
 685         case CAP_HWCAP:
 686                 rc = (elf_hwcap & cap->hwcap) != 0;
 687                 break;
 688 #ifdef CONFIG_COMPAT
 689         case CAP_COMPAT_HWCAP:
 690                 rc = (compat_elf_hwcap & (u32)cap->hwcap) != 0;
 691                 break;
 692         case CAP_COMPAT_HWCAP2:
 693                 rc = (compat_elf_hwcap2 & (u32)cap->hwcap) != 0;
 694                 break;
 695 #endif
 696         default:
 697                 WARN_ON(1);
 698                 rc = false;
 699         }
 700
 701         return rc;
 702 }
 703
 704 static void setup_cpu_hwcaps(void)
 705 {
 706         int i;
 707         const struct arm64_cpu_capabilities *hwcaps = arm64_hwcaps;
 708
 709         for (i = 0; hwcaps[i].desc; i++)
 710                 if (hwcaps[i].matches(&hwcaps[i]))
 711                         cap_set_hwcap(&hwcaps[i]);
 712 }
 713
 714 void update_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
 715                             const char *info)
 716 {
 717         int i;
 718
 719         for (i = 0; caps[i].desc; i++) {
 720                 if (!caps[i].matches(&caps[i]))
 721                         continue;
 722
 723                 if (!cpus_have_cap(caps[i].capability))
 724                         pr_info("%s %s\n", info, caps[i].desc);
 725                 cpus_set_cap(caps[i].capability);
 726         }
 727 }
 728
 729 /*
 730  * Run through the enabled capabilities and enable() it on all active
 731  * CPUs
 732  */
 733 void enable_cpu_capabilities(const struct arm64_cpu_capabilities *caps)
 734 {
 735         int i;
 736
 737         for (i = 0; caps[i].desc; i++)
 738                 if (caps[i].enable && cpus_have_cap(caps[i].capability))
 739                         on_each_cpu(caps[i].enable, NULL, true);
 740 }
 741
 742 #ifdef CONFIG_HOTPLUG_CPU
 743
 744 /*
 745  * Flag to indicate if we have computed the system wide
 746  * capabilities based on the boot time active CPUs. This
 747  * will be used to determine if a new booting CPU should
 748  * go through the verification process to make sure that it
 749  * supports the system capabilities, without using a hotplug
 750  * notifier.
 751  */
 752 static bool sys_caps_initialised;
 753
 754 static inline void set_sys_caps_initialised(void)
 755 {
 756         sys_caps_initialised = true;
 757 }
 758
 759 /*
 760  * __raw_read_system_reg() - Used by a STARTING cpu before cpuinfo is populated.
 761  */
 762 static u64 __raw_read_system_reg(u32 sys_id)
 763 {
 764         switch (sys_id) {
 765         case SYS_ID_PFR0_EL1:           return (u64)read_cpuid(ID_PFR0_EL1);
 766         case SYS_ID_PFR1_EL1:           return (u64)read_cpuid(ID_PFR1_EL1);
 767         case SYS_ID_DFR0_EL1:           return (u64)read_cpuid(ID_DFR0_EL1);
 768         case SYS_ID_MMFR0_EL1:          return (u64)read_cpuid(ID_MMFR0_EL1);
 769         case SYS_ID_MMFR1_EL1:          return (u64)read_cpuid(ID_MMFR1_EL1);
 770         case SYS_ID_MMFR2_EL1:          return (u64)read_cpuid(ID_MMFR2_EL1);
 771         case SYS_ID_MMFR3_EL1:          return (u64)read_cpuid(ID_MMFR3_EL1);
 772         case SYS_ID_ISAR0_EL1:          return (u64)read_cpuid(ID_ISAR0_EL1);
 773         case SYS_ID_ISAR1_EL1:          return (u64)read_cpuid(ID_ISAR1_EL1);
 774         case SYS_ID_ISAR2_EL1:          return (u64)read_cpuid(ID_ISAR2_EL1);
 775         case SYS_ID_ISAR3_EL1:          return (u64)read_cpuid(ID_ISAR3_EL1);
 776         case SYS_ID_ISAR4_EL1:          return (u64)read_cpuid(ID_ISAR4_EL1);
 777         case SYS_ID_ISAR5_EL1:          return (u64)read_cpuid(ID_ISAR4_EL1);
 778         case SYS_MVFR0_EL1:             return (u64)read_cpuid(MVFR0_EL1);
 779         case SYS_MVFR1_EL1:             return (u64)read_cpuid(MVFR1_EL1);
 780         case SYS_MVFR2_EL1:             return (u64)read_cpuid(MVFR2_EL1);
 781
 782         case SYS_ID_AA64PFR0_EL1:       return (u64)read_cpuid(ID_AA64PFR0_EL1);
 783         case SYS_ID_AA64PFR1_EL1:       return (u64)read_cpuid(ID_AA64PFR0_EL1);
 784         case SYS_ID_AA64DFR0_EL1:       return (u64)read_cpuid(ID_AA64DFR0_EL1);
 785         case SYS_ID_AA64DFR1_EL1:       return (u64)read_cpuid(ID_AA64DFR0_EL1);
 786         case SYS_ID_AA64MMFR0_EL1:      return (u64)read_cpuid(ID_AA64MMFR0_EL1);
 787         case SYS_ID_AA64MMFR1_EL1:      return (u64)read_cpuid(ID_AA64MMFR1_EL1);
 788         case SYS_ID_AA64ISAR0_EL1:      return (u64)read_cpuid(ID_AA64ISAR0_EL1);
 789         case SYS_ID_AA64ISAR1_EL1:      return (u64)read_cpuid(ID_AA64ISAR1_EL1);
 790
 791         case SYS_CNTFRQ_EL0:            return (u64)read_cpuid(CNTFRQ_EL0);
 792         case SYS_CTR_EL0:               return (u64)read_cpuid(CTR_EL0);
 793         case SYS_DCZID_EL0:             return (u64)read_cpuid(DCZID_EL0);
 794         default:
 795                 BUG();
 796                 return 0;
 797         }
 798 }
 799
 800 /*
 801  * Park the CPU which doesn't have the capability as advertised
 802  * by the system.
 803  */
 804 static void fail_incapable_cpu(char *cap_type,
 805                                  const struct arm64_cpu_capabilities *cap)
 806 {
 807         int cpu = smp_processor_id();
 808
 809         pr_crit("CPU%d: missing %s : %s\n", cpu, cap_type, cap->desc);
 810         /* Mark this CPU absent */
 811         set_cpu_present(cpu, 0);
 812
 813         /* Check if we can park ourselves */
 814         if (cpu_ops[cpu] && cpu_ops[cpu]->cpu_die)
 815                 cpu_ops[cpu]->cpu_die(cpu);
 816         asm(
 817         "1:     wfe\n"
 818         "       wfi\n"
 819         "       b       1b");
 820 }
 821
 822 /*
 823  * Run through the enabled system capabilities and enable() it on this CPU.
 824  * The capabilities were decided based on the available CPUs at the boot time.
 825  * Any new CPU should match the system wide status of the capability. If the
 826  * new CPU doesn't have a capability which the system now has enabled, we
 827  * cannot do anything to fix it up and could cause unexpected failures. So
 828  * we park the CPU.
 829  */
 830 void verify_local_cpu_capabilities(void)
 831 {
 832         int i;
 833         const struct arm64_cpu_capabilities *caps;
 834
 835         /*
 836          * If we haven't computed the system capabilities, there is nothing
 837          * to verify.
 838          */
 839         if (!sys_caps_initialised)
 840                 return;
 841
 842         caps = arm64_features;
 843         for (i = 0; caps[i].desc; i++) {
 844                 if (!cpus_have_cap(caps[i].capability) || !caps[i].sys_reg)
 845                         continue;
 846                 /*
 847                  * If the new CPU misses an advertised feature, we cannot proceed
 848                  * further, park the cpu.
 849                  */
 850                 if (!feature_matches(__raw_read_system_reg(caps[i].sys_reg), &caps[i]))
 851                         fail_incapable_cpu("arm64_features", &caps[i]);
 852                 if (caps[i].enable)
 853                         caps[i].enable(NULL);
 854         }
 855
 856         for (i = 0, caps = arm64_hwcaps; caps[i].desc; i++) {
 857                 if (!cpus_have_hwcap(&caps[i]))
 858                         continue;
 859                 if (!feature_matches(__raw_read_system_reg(caps[i].sys_reg), &caps[i]))
 860                         fail_incapable_cpu("arm64_hwcaps", &caps[i]);
 861         }
 862 }
 863
 864 #else   /* !CONFIG_HOTPLUG_CPU */
 865
 866 static inline void set_sys_caps_initialised(void)
 867 {
 868 }
 869
 870 #endif  /* CONFIG_HOTPLUG_CPU */
 871
 872 static void setup_feature_capabilities(void)
 873 {
 874         update_cpu_capabilities(arm64_features, "detected feature:");
 875         enable_cpu_capabilities(arm64_features);
 876 }
 877
 878 void __init setup_cpu_features(void)
 879 {
 880         u32 cwg;
 881         int cls;
 882
 883         /* Set the CPU feature capabilies */
 884         setup_feature_capabilities();
 885         setup_cpu_hwcaps();
 886
 887         /* Advertise that we have computed the system capabilities */
 888         set_sys_caps_initialised();
 889
 890         /*
 891          * Check for sane CTR_EL0.CWG value.
 892          */
 893         cwg = cache_type_cwg();
 894         cls = cache_line_size();
 895         if (!cwg)
 896                 pr_warn("No Cache Writeback Granule information, assuming cache line size %d\n",
 897                         cls);
 898         if (L1_CACHE_BYTES < cls)
 899                 pr_warn("L1_CACHE_BYTES smaller than the Cache Writeback Granule (%d < %d)\n",
 900                         L1_CACHE_BYTES, cls);
 901 }