cpuinfo.c 14 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * Record and handle CPU attributes.
  4. *
  5. * Copyright (C) 2014 ARM Ltd.
  6. */
  7. #include <asm/arch_timer.h>
  8. #include <asm/cache.h>
  9. #include <asm/cpu.h>
  10. #include <asm/cputype.h>
  11. #include <asm/cpufeature.h>
  12. #include <asm/fpsimd.h>
  13. #include <linux/bitops.h>
  14. #include <linux/bug.h>
  15. #include <linux/compat.h>
  16. #include <linux/elf.h>
  17. #include <linux/init.h>
  18. #include <linux/kernel.h>
  19. #include <linux/personality.h>
  20. #include <linux/preempt.h>
  21. #include <linux/printk.h>
  22. #include <linux/seq_file.h>
  23. #include <linux/sched.h>
  24. #include <linux/smp.h>
  25. #include <linux/delay.h>
  26. /*
  27. * In case the boot CPU is hotpluggable, we record its initial state and
  28. * current state separately. Certain system registers may contain different
  29. * values depending on configuration at or after reset.
  30. */
  31. DEFINE_PER_CPU(struct cpuinfo_arm64, cpu_data);
  32. static struct cpuinfo_arm64 boot_cpu_data;
  33. static inline const char *icache_policy_str(int l1ip)
  34. {
  35. switch (l1ip) {
  36. case CTR_EL0_L1Ip_VPIPT:
  37. return "VPIPT";
  38. case CTR_EL0_L1Ip_VIPT:
  39. return "VIPT";
  40. case CTR_EL0_L1Ip_PIPT:
  41. return "PIPT";
  42. default:
  43. return "RESERVED/UNKNOWN";
  44. }
  45. }
  46. unsigned long __icache_flags;
  47. static const char *const hwcap_str[] = {
  48. [KERNEL_HWCAP_FP] = "fp",
  49. [KERNEL_HWCAP_ASIMD] = "asimd",
  50. [KERNEL_HWCAP_EVTSTRM] = "evtstrm",
  51. [KERNEL_HWCAP_AES] = "aes",
  52. [KERNEL_HWCAP_PMULL] = "pmull",
  53. [KERNEL_HWCAP_SHA1] = "sha1",
  54. [KERNEL_HWCAP_SHA2] = "sha2",
  55. [KERNEL_HWCAP_CRC32] = "crc32",
  56. [KERNEL_HWCAP_ATOMICS] = "atomics",
  57. [KERNEL_HWCAP_FPHP] = "fphp",
  58. [KERNEL_HWCAP_ASIMDHP] = "asimdhp",
  59. [KERNEL_HWCAP_CPUID] = "cpuid",
  60. [KERNEL_HWCAP_ASIMDRDM] = "asimdrdm",
  61. [KERNEL_HWCAP_JSCVT] = "jscvt",
  62. [KERNEL_HWCAP_FCMA] = "fcma",
  63. [KERNEL_HWCAP_LRCPC] = "lrcpc",
  64. [KERNEL_HWCAP_DCPOP] = "dcpop",
  65. [KERNEL_HWCAP_SHA3] = "sha3",
  66. [KERNEL_HWCAP_SM3] = "sm3",
  67. [KERNEL_HWCAP_SM4] = "sm4",
  68. [KERNEL_HWCAP_ASIMDDP] = "asimddp",
  69. [KERNEL_HWCAP_SHA512] = "sha512",
  70. [KERNEL_HWCAP_SVE] = "sve",
  71. [KERNEL_HWCAP_ASIMDFHM] = "asimdfhm",
  72. [KERNEL_HWCAP_DIT] = "dit",
  73. [KERNEL_HWCAP_USCAT] = "uscat",
  74. [KERNEL_HWCAP_ILRCPC] = "ilrcpc",
  75. [KERNEL_HWCAP_FLAGM] = "flagm",
  76. [KERNEL_HWCAP_SSBS] = "ssbs",
  77. [KERNEL_HWCAP_SB] = "sb",
  78. [KERNEL_HWCAP_PACA] = "paca",
  79. [KERNEL_HWCAP_PACG] = "pacg",
  80. [KERNEL_HWCAP_DCPODP] = "dcpodp",
  81. [KERNEL_HWCAP_SVE2] = "sve2",
  82. [KERNEL_HWCAP_SVEAES] = "sveaes",
  83. [KERNEL_HWCAP_SVEPMULL] = "svepmull",
  84. [KERNEL_HWCAP_SVEBITPERM] = "svebitperm",
  85. [KERNEL_HWCAP_SVESHA3] = "svesha3",
  86. [KERNEL_HWCAP_SVESM4] = "svesm4",
  87. [KERNEL_HWCAP_FLAGM2] = "flagm2",
  88. [KERNEL_HWCAP_FRINT] = "frint",
  89. [KERNEL_HWCAP_SVEI8MM] = "svei8mm",
  90. [KERNEL_HWCAP_SVEF32MM] = "svef32mm",
  91. [KERNEL_HWCAP_SVEF64MM] = "svef64mm",
  92. [KERNEL_HWCAP_SVEBF16] = "svebf16",
  93. [KERNEL_HWCAP_I8MM] = "i8mm",
  94. [KERNEL_HWCAP_BF16] = "bf16",
  95. [KERNEL_HWCAP_DGH] = "dgh",
  96. [KERNEL_HWCAP_RNG] = "rng",
  97. [KERNEL_HWCAP_BTI] = "bti",
  98. [KERNEL_HWCAP_MTE] = "mte",
  99. [KERNEL_HWCAP_ECV] = "ecv",
  100. [KERNEL_HWCAP_AFP] = "afp",
  101. [KERNEL_HWCAP_RPRES] = "rpres",
  102. [KERNEL_HWCAP_MTE3] = "mte3",
  103. [KERNEL_HWCAP_SME] = "sme",
  104. [KERNEL_HWCAP_SME_I16I64] = "smei16i64",
  105. [KERNEL_HWCAP_SME_F64F64] = "smef64f64",
  106. [KERNEL_HWCAP_SME_I8I32] = "smei8i32",
  107. [KERNEL_HWCAP_SME_F16F32] = "smef16f32",
  108. [KERNEL_HWCAP_SME_B16F32] = "smeb16f32",
  109. [KERNEL_HWCAP_SME_F32F32] = "smef32f32",
  110. [KERNEL_HWCAP_SME_FA64] = "smefa64",
  111. [KERNEL_HWCAP_WFXT] = "wfxt",
  112. [KERNEL_HWCAP_EBF16] = "ebf16",
  113. [KERNEL_HWCAP_SVE_EBF16] = "sveebf16",
  114. };
  115. #ifdef CONFIG_COMPAT
  116. #define COMPAT_KERNEL_HWCAP(x) const_ilog2(COMPAT_HWCAP_ ## x)
  117. static const char *const compat_hwcap_str[] = {
  118. [COMPAT_KERNEL_HWCAP(SWP)] = "swp",
  119. [COMPAT_KERNEL_HWCAP(HALF)] = "half",
  120. [COMPAT_KERNEL_HWCAP(THUMB)] = "thumb",
  121. [COMPAT_KERNEL_HWCAP(26BIT)] = NULL, /* Not possible on arm64 */
  122. [COMPAT_KERNEL_HWCAP(FAST_MULT)] = "fastmult",
  123. [COMPAT_KERNEL_HWCAP(FPA)] = NULL, /* Not possible on arm64 */
  124. [COMPAT_KERNEL_HWCAP(VFP)] = "vfp",
  125. [COMPAT_KERNEL_HWCAP(EDSP)] = "edsp",
  126. [COMPAT_KERNEL_HWCAP(JAVA)] = NULL, /* Not possible on arm64 */
  127. [COMPAT_KERNEL_HWCAP(IWMMXT)] = NULL, /* Not possible on arm64 */
  128. [COMPAT_KERNEL_HWCAP(CRUNCH)] = NULL, /* Not possible on arm64 */
  129. [COMPAT_KERNEL_HWCAP(THUMBEE)] = NULL, /* Not possible on arm64 */
  130. [COMPAT_KERNEL_HWCAP(NEON)] = "neon",
  131. [COMPAT_KERNEL_HWCAP(VFPv3)] = "vfpv3",
  132. [COMPAT_KERNEL_HWCAP(VFPV3D16)] = NULL, /* Not possible on arm64 */
  133. [COMPAT_KERNEL_HWCAP(TLS)] = "tls",
  134. [COMPAT_KERNEL_HWCAP(VFPv4)] = "vfpv4",
  135. [COMPAT_KERNEL_HWCAP(IDIVA)] = "idiva",
  136. [COMPAT_KERNEL_HWCAP(IDIVT)] = "idivt",
  137. [COMPAT_KERNEL_HWCAP(VFPD32)] = NULL, /* Not possible on arm64 */
  138. [COMPAT_KERNEL_HWCAP(LPAE)] = "lpae",
  139. [COMPAT_KERNEL_HWCAP(EVTSTRM)] = "evtstrm",
  140. };
  141. #define COMPAT_KERNEL_HWCAP2(x) const_ilog2(COMPAT_HWCAP2_ ## x)
  142. static const char *const compat_hwcap2_str[] = {
  143. [COMPAT_KERNEL_HWCAP2(AES)] = "aes",
  144. [COMPAT_KERNEL_HWCAP2(PMULL)] = "pmull",
  145. [COMPAT_KERNEL_HWCAP2(SHA1)] = "sha1",
  146. [COMPAT_KERNEL_HWCAP2(SHA2)] = "sha2",
  147. [COMPAT_KERNEL_HWCAP2(CRC32)] = "crc32",
  148. };
  149. #endif /* CONFIG_COMPAT */
  150. static int c_show(struct seq_file *m, void *v)
  151. {
  152. int i, j;
  153. bool compat = personality(current->personality) == PER_LINUX32;
  154. for_each_online_cpu(i) {
  155. struct cpuinfo_arm64 *cpuinfo = &per_cpu(cpu_data, i);
  156. u32 midr = cpuinfo->reg_midr;
  157. /*
  158. * glibc reads /proc/cpuinfo to determine the number of
  159. * online processors, looking for lines beginning with
  160. * "processor". Give glibc what it expects.
  161. */
  162. seq_printf(m, "processor\t: %d\n", i);
  163. if (compat)
  164. seq_printf(m, "model name\t: ARMv8 Processor rev %d (%s)\n",
  165. MIDR_REVISION(midr), COMPAT_ELF_PLATFORM);
  166. seq_printf(m, "BogoMIPS\t: %lu.%02lu\n",
  167. loops_per_jiffy / (500000UL/HZ),
  168. loops_per_jiffy / (5000UL/HZ) % 100);
  169. /*
  170. * Dump out the common processor features in a single line.
  171. * Userspace should read the hwcaps with getauxval(AT_HWCAP)
  172. * rather than attempting to parse this, but there's a body of
  173. * software which does already (at least for 32-bit).
  174. */
  175. seq_puts(m, "Features\t:");
  176. if (compat) {
  177. #ifdef CONFIG_COMPAT
  178. for (j = 0; j < ARRAY_SIZE(compat_hwcap_str); j++) {
  179. if (compat_elf_hwcap & (1 << j)) {
  180. /*
  181. * Warn once if any feature should not
  182. * have been present on arm64 platform.
  183. */
  184. if (WARN_ON_ONCE(!compat_hwcap_str[j]))
  185. continue;
  186. seq_printf(m, " %s", compat_hwcap_str[j]);
  187. }
  188. }
  189. for (j = 0; j < ARRAY_SIZE(compat_hwcap2_str); j++)
  190. if (compat_elf_hwcap2 & (1 << j))
  191. seq_printf(m, " %s", compat_hwcap2_str[j]);
  192. #endif /* CONFIG_COMPAT */
  193. } else {
  194. for (j = 0; j < ARRAY_SIZE(hwcap_str); j++)
  195. if (cpu_have_feature(j))
  196. seq_printf(m, " %s", hwcap_str[j]);
  197. }
  198. seq_puts(m, "\n");
  199. seq_printf(m, "CPU implementer\t: 0x%02x\n",
  200. MIDR_IMPLEMENTOR(midr));
  201. seq_printf(m, "CPU architecture: 8\n");
  202. seq_printf(m, "CPU variant\t: 0x%x\n", MIDR_VARIANT(midr));
  203. seq_printf(m, "CPU part\t: 0x%03x\n", MIDR_PARTNUM(midr));
  204. seq_printf(m, "CPU revision\t: %d\n\n", MIDR_REVISION(midr));
  205. }
  206. return 0;
  207. }
  208. static void *c_start(struct seq_file *m, loff_t *pos)
  209. {
  210. return *pos < 1 ? (void *)1 : NULL;
  211. }
  212. static void *c_next(struct seq_file *m, void *v, loff_t *pos)
  213. {
  214. ++*pos;
  215. return NULL;
  216. }
  217. static void c_stop(struct seq_file *m, void *v)
  218. {
  219. }
  220. const struct seq_operations cpuinfo_op = {
  221. .start = c_start,
  222. .next = c_next,
  223. .stop = c_stop,
  224. .show = c_show
  225. };
  226. static struct kobj_type cpuregs_kobj_type = {
  227. .sysfs_ops = &kobj_sysfs_ops,
  228. };
  229. /*
  230. * The ARM ARM uses the phrase "32-bit register" to describe a register
  231. * whose upper 32 bits are RES0 (per C5.1.1, ARM DDI 0487A.i), however
  232. * no statement is made as to whether the upper 32 bits will or will not
  233. * be made use of in future, and between ARM DDI 0487A.c and ARM DDI
  234. * 0487A.d CLIDR_EL1 was expanded from 32-bit to 64-bit.
  235. *
  236. * Thus, while both MIDR_EL1 and REVIDR_EL1 are described as 32-bit
  237. * registers, we expose them both as 64 bit values to cater for possible
  238. * future expansion without an ABI break.
  239. */
  240. #define kobj_to_cpuinfo(kobj) container_of(kobj, struct cpuinfo_arm64, kobj)
  241. #define CPUREGS_ATTR_RO(_name, _field) \
  242. static ssize_t _name##_show(struct kobject *kobj, \
  243. struct kobj_attribute *attr, char *buf) \
  244. { \
  245. struct cpuinfo_arm64 *info = kobj_to_cpuinfo(kobj); \
  246. \
  247. if (info->reg_midr) \
  248. return sprintf(buf, "0x%016llx\n", info->reg_##_field); \
  249. else \
  250. return 0; \
  251. } \
  252. static struct kobj_attribute cpuregs_attr_##_name = __ATTR_RO(_name)
  253. CPUREGS_ATTR_RO(midr_el1, midr);
  254. CPUREGS_ATTR_RO(revidr_el1, revidr);
  255. CPUREGS_ATTR_RO(smidr_el1, smidr);
  256. static struct attribute *cpuregs_id_attrs[] = {
  257. &cpuregs_attr_midr_el1.attr,
  258. &cpuregs_attr_revidr_el1.attr,
  259. NULL
  260. };
  261. static const struct attribute_group cpuregs_attr_group = {
  262. .attrs = cpuregs_id_attrs,
  263. .name = "identification"
  264. };
  265. static struct attribute *sme_cpuregs_id_attrs[] = {
  266. &cpuregs_attr_smidr_el1.attr,
  267. NULL
  268. };
  269. static const struct attribute_group sme_cpuregs_attr_group = {
  270. .attrs = sme_cpuregs_id_attrs,
  271. .name = "identification"
  272. };
  273. static int cpuid_cpu_online(unsigned int cpu)
  274. {
  275. int rc;
  276. struct device *dev;
  277. struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu);
  278. dev = get_cpu_device(cpu);
  279. if (!dev) {
  280. rc = -ENODEV;
  281. goto out;
  282. }
  283. rc = kobject_add(&info->kobj, &dev->kobj, "regs");
  284. if (rc)
  285. goto out;
  286. rc = sysfs_create_group(&info->kobj, &cpuregs_attr_group);
  287. if (rc)
  288. kobject_del(&info->kobj);
  289. if (system_supports_sme())
  290. rc = sysfs_merge_group(&info->kobj, &sme_cpuregs_attr_group);
  291. out:
  292. return rc;
  293. }
  294. static int cpuid_cpu_offline(unsigned int cpu)
  295. {
  296. struct device *dev;
  297. struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu);
  298. dev = get_cpu_device(cpu);
  299. if (!dev)
  300. return -ENODEV;
  301. if (info->kobj.parent) {
  302. sysfs_remove_group(&info->kobj, &cpuregs_attr_group);
  303. kobject_del(&info->kobj);
  304. }
  305. return 0;
  306. }
  307. static int __init cpuinfo_regs_init(void)
  308. {
  309. int cpu, ret;
  310. for_each_possible_cpu(cpu) {
  311. struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu);
  312. kobject_init(&info->kobj, &cpuregs_kobj_type);
  313. }
  314. ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "arm64/cpuinfo:online",
  315. cpuid_cpu_online, cpuid_cpu_offline);
  316. if (ret < 0) {
  317. pr_err("cpuinfo: failed to register hotplug callbacks.\n");
  318. return ret;
  319. }
  320. return 0;
  321. }
  322. device_initcall(cpuinfo_regs_init);
  323. static void cpuinfo_detect_icache_policy(struct cpuinfo_arm64 *info)
  324. {
  325. unsigned int cpu = smp_processor_id();
  326. u32 l1ip = CTR_L1IP(info->reg_ctr);
  327. switch (l1ip) {
  328. case CTR_EL0_L1Ip_PIPT:
  329. break;
  330. case CTR_EL0_L1Ip_VPIPT:
  331. set_bit(ICACHEF_VPIPT, &__icache_flags);
  332. break;
  333. case CTR_EL0_L1Ip_VIPT:
  334. default:
  335. /* Assume aliasing */
  336. set_bit(ICACHEF_ALIASING, &__icache_flags);
  337. break;
  338. }
  339. pr_info("Detected %s I-cache on CPU%d\n", icache_policy_str(l1ip), cpu);
  340. }
  341. static void __cpuinfo_store_cpu_32bit(struct cpuinfo_32bit *info)
  342. {
  343. info->reg_id_dfr0 = read_cpuid(ID_DFR0_EL1);
  344. info->reg_id_dfr1 = read_cpuid(ID_DFR1_EL1);
  345. info->reg_id_isar0 = read_cpuid(ID_ISAR0_EL1);
  346. info->reg_id_isar1 = read_cpuid(ID_ISAR1_EL1);
  347. info->reg_id_isar2 = read_cpuid(ID_ISAR2_EL1);
  348. info->reg_id_isar3 = read_cpuid(ID_ISAR3_EL1);
  349. info->reg_id_isar4 = read_cpuid(ID_ISAR4_EL1);
  350. info->reg_id_isar5 = read_cpuid(ID_ISAR5_EL1);
  351. info->reg_id_isar6 = read_cpuid(ID_ISAR6_EL1);
  352. info->reg_id_mmfr0 = read_cpuid(ID_MMFR0_EL1);
  353. info->reg_id_mmfr1 = read_cpuid(ID_MMFR1_EL1);
  354. info->reg_id_mmfr2 = read_cpuid(ID_MMFR2_EL1);
  355. info->reg_id_mmfr3 = read_cpuid(ID_MMFR3_EL1);
  356. info->reg_id_mmfr4 = read_cpuid(ID_MMFR4_EL1);
  357. info->reg_id_mmfr5 = read_cpuid(ID_MMFR5_EL1);
  358. info->reg_id_pfr0 = read_cpuid(ID_PFR0_EL1);
  359. info->reg_id_pfr1 = read_cpuid(ID_PFR1_EL1);
  360. info->reg_id_pfr2 = read_cpuid(ID_PFR2_EL1);
  361. info->reg_mvfr0 = read_cpuid(MVFR0_EL1);
  362. info->reg_mvfr1 = read_cpuid(MVFR1_EL1);
  363. info->reg_mvfr2 = read_cpuid(MVFR2_EL1);
  364. }
  365. static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info)
  366. {
  367. info->reg_cntfrq = arch_timer_get_cntfrq();
  368. /*
  369. * Use the effective value of the CTR_EL0 than the raw value
  370. * exposed by the CPU. CTR_EL0.IDC field value must be interpreted
  371. * with the CLIDR_EL1 fields to avoid triggering false warnings
  372. * when there is a mismatch across the CPUs. Keep track of the
  373. * effective value of the CTR_EL0 in our internal records for
  374. * accurate sanity check and feature enablement.
  375. */
  376. info->reg_ctr = read_cpuid_effective_cachetype();
  377. info->reg_dczid = read_cpuid(DCZID_EL0);
  378. info->reg_midr = read_cpuid_id();
  379. info->reg_revidr = read_cpuid(REVIDR_EL1);
  380. info->reg_id_aa64dfr0 = read_cpuid(ID_AA64DFR0_EL1);
  381. info->reg_id_aa64dfr1 = read_cpuid(ID_AA64DFR1_EL1);
  382. info->reg_id_aa64isar0 = read_cpuid(ID_AA64ISAR0_EL1);
  383. info->reg_id_aa64isar1 = read_cpuid(ID_AA64ISAR1_EL1);
  384. info->reg_id_aa64isar2 = read_cpuid(ID_AA64ISAR2_EL1);
  385. info->reg_id_aa64mmfr0 = read_cpuid(ID_AA64MMFR0_EL1);
  386. info->reg_id_aa64mmfr1 = read_cpuid(ID_AA64MMFR1_EL1);
  387. info->reg_id_aa64mmfr2 = read_cpuid(ID_AA64MMFR2_EL1);
  388. info->reg_id_aa64pfr0 = read_cpuid(ID_AA64PFR0_EL1);
  389. info->reg_id_aa64pfr1 = read_cpuid(ID_AA64PFR1_EL1);
  390. info->reg_id_aa64zfr0 = read_cpuid(ID_AA64ZFR0_EL1);
  391. info->reg_id_aa64smfr0 = read_cpuid(ID_AA64SMFR0_EL1);
  392. if (id_aa64pfr1_mte(info->reg_id_aa64pfr1))
  393. info->reg_gmid = read_cpuid(GMID_EL1);
  394. if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0))
  395. __cpuinfo_store_cpu_32bit(&info->aarch32);
  396. cpuinfo_detect_icache_policy(info);
  397. }
  398. void cpuinfo_store_cpu(void)
  399. {
  400. struct cpuinfo_arm64 *info = this_cpu_ptr(&cpu_data);
  401. __cpuinfo_store_cpu(info);
  402. update_cpu_features(smp_processor_id(), info, &boot_cpu_data);
  403. }
  404. void __init cpuinfo_store_boot_cpu(void)
  405. {
  406. struct cpuinfo_arm64 *info = &per_cpu(cpu_data, 0);
  407. __cpuinfo_store_cpu(info);
  408. boot_cpu_data = *info;
  409. init_cpu_features(&boot_cpu_data);
  410. }