1 // SPDX-License-Identifier: GPL-2.0-only
3 * Record and handle CPU attributes.
5 * Copyright (C) 2014 ARM Ltd.
7 #include <asm/arch_timer.h>
10 #include <asm/cputype.h>
11 #include <asm/cpufeature.h>
12 #include <asm/fpsimd.h>
14 #include <linux/bitops.h>
15 #include <linux/bug.h>
16 #include <linux/compat.h>
17 #include <linux/elf.h>
18 #include <linux/init.h>
19 #include <linux/kernel.h>
20 #include <linux/personality.h>
21 #include <linux/preempt.h>
22 #include <linux/printk.h>
23 #include <linux/seq_file.h>
24 #include <linux/sched.h>
25 #include <linux/smp.h>
26 #include <linux/delay.h>
29 * In case the boot CPU is hotpluggable, we record its initial state and
30 * current state separately. Certain system registers may contain different
31 * values depending on configuration at or after reset.
33 DEFINE_PER_CPU(struct cpuinfo_arm64, cpu_data);
34 static struct cpuinfo_arm64 boot_cpu_data;
36 static inline const char *icache_policy_str(int l1ip)
39 case CTR_EL0_L1Ip_VPIPT:
41 case CTR_EL0_L1Ip_VIPT:
43 case CTR_EL0_L1Ip_PIPT:
46 return "RESERVED/UNKNOWN";
50 unsigned long __icache_flags;
52 static const char *const hwcap_str[] = {
53 [KERNEL_HWCAP_FP] = "fp",
54 [KERNEL_HWCAP_ASIMD] = "asimd",
55 [KERNEL_HWCAP_EVTSTRM] = "evtstrm",
56 [KERNEL_HWCAP_AES] = "aes",
57 [KERNEL_HWCAP_PMULL] = "pmull",
58 [KERNEL_HWCAP_SHA1] = "sha1",
59 [KERNEL_HWCAP_SHA2] = "sha2",
60 [KERNEL_HWCAP_CRC32] = "crc32",
61 [KERNEL_HWCAP_ATOMICS] = "atomics",
62 [KERNEL_HWCAP_FPHP] = "fphp",
63 [KERNEL_HWCAP_ASIMDHP] = "asimdhp",
64 [KERNEL_HWCAP_CPUID] = "cpuid",
65 [KERNEL_HWCAP_ASIMDRDM] = "asimdrdm",
66 [KERNEL_HWCAP_JSCVT] = "jscvt",
67 [KERNEL_HWCAP_FCMA] = "fcma",
68 [KERNEL_HWCAP_LRCPC] = "lrcpc",
69 [KERNEL_HWCAP_DCPOP] = "dcpop",
70 [KERNEL_HWCAP_SHA3] = "sha3",
71 [KERNEL_HWCAP_SM3] = "sm3",
72 [KERNEL_HWCAP_SM4] = "sm4",
73 [KERNEL_HWCAP_ASIMDDP] = "asimddp",
74 [KERNEL_HWCAP_SHA512] = "sha512",
75 [KERNEL_HWCAP_SVE] = "sve",
76 [KERNEL_HWCAP_ASIMDFHM] = "asimdfhm",
77 [KERNEL_HWCAP_DIT] = "dit",
78 [KERNEL_HWCAP_USCAT] = "uscat",
79 [KERNEL_HWCAP_ILRCPC] = "ilrcpc",
80 [KERNEL_HWCAP_FLAGM] = "flagm",
81 [KERNEL_HWCAP_SSBS] = "ssbs",
82 [KERNEL_HWCAP_SB] = "sb",
83 [KERNEL_HWCAP_PACA] = "paca",
84 [KERNEL_HWCAP_PACG] = "pacg",
85 [KERNEL_HWCAP_DCPODP] = "dcpodp",
86 [KERNEL_HWCAP_SVE2] = "sve2",
87 [KERNEL_HWCAP_SVEAES] = "sveaes",
88 [KERNEL_HWCAP_SVEPMULL] = "svepmull",
89 [KERNEL_HWCAP_SVEBITPERM] = "svebitperm",
90 [KERNEL_HWCAP_SVESHA3] = "svesha3",
91 [KERNEL_HWCAP_SVESM4] = "svesm4",
92 [KERNEL_HWCAP_FLAGM2] = "flagm2",
93 [KERNEL_HWCAP_FRINT] = "frint",
94 [KERNEL_HWCAP_SVEI8MM] = "svei8mm",
95 [KERNEL_HWCAP_SVEF32MM] = "svef32mm",
96 [KERNEL_HWCAP_SVEF64MM] = "svef64mm",
97 [KERNEL_HWCAP_SVEBF16] = "svebf16",
98 [KERNEL_HWCAP_I8MM] = "i8mm",
99 [KERNEL_HWCAP_BF16] = "bf16",
100 [KERNEL_HWCAP_DGH] = "dgh",
101 [KERNEL_HWCAP_RNG] = "rng",
102 [KERNEL_HWCAP_BTI] = "bti",
103 [KERNEL_HWCAP_MTE] = "mte",
104 [KERNEL_HWCAP_ECV] = "ecv",
105 [KERNEL_HWCAP_AFP] = "afp",
106 [KERNEL_HWCAP_RPRES] = "rpres",
107 [KERNEL_HWCAP_MTE3] = "mte3",
108 [KERNEL_HWCAP_SME] = "sme",
109 [KERNEL_HWCAP_SME_I16I64] = "smei16i64",
110 [KERNEL_HWCAP_SME_F64F64] = "smef64f64",
111 [KERNEL_HWCAP_SME_I8I32] = "smei8i32",
112 [KERNEL_HWCAP_SME_F16F32] = "smef16f32",
113 [KERNEL_HWCAP_SME_B16F32] = "smeb16f32",
114 [KERNEL_HWCAP_SME_F32F32] = "smef32f32",
115 [KERNEL_HWCAP_SME_FA64] = "smefa64",
116 [KERNEL_HWCAP_WFXT] = "wfxt",
117 [KERNEL_HWCAP_EBF16] = "ebf16",
118 [KERNEL_HWCAP_SVE_EBF16] = "sveebf16",
119 [KERNEL_HWCAP_CSSC] = "cssc",
120 [KERNEL_HWCAP_RPRFM] = "rprfm",
121 [KERNEL_HWCAP_SVE2P1] = "sve2p1",
122 [KERNEL_HWCAP_SME2] = "sme2",
123 [KERNEL_HWCAP_SME2P1] = "sme2p1",
124 [KERNEL_HWCAP_SME_I16I32] = "smei16i32",
125 [KERNEL_HWCAP_SME_BI32I32] = "smebi32i32",
126 [KERNEL_HWCAP_SME_B16B16] = "smeb16b16",
127 [KERNEL_HWCAP_SME_F16F16] = "smef16f16",
128 [KERNEL_HWCAP_MOPS] = "mops",
129 [KERNEL_HWCAP_HBC] = "hbc",
130 [KERNEL_HWCAP_SVE_B16B16] = "sveb16b16",
131 [KERNEL_HWCAP_LRCPC3] = "lrcpc3",
132 [KERNEL_HWCAP_LSE128] = "lse128",
136 #define COMPAT_KERNEL_HWCAP(x) const_ilog2(COMPAT_HWCAP_ ## x)
137 static const char *const compat_hwcap_str[] = {
138 [COMPAT_KERNEL_HWCAP(SWP)] = "swp",
139 [COMPAT_KERNEL_HWCAP(HALF)] = "half",
140 [COMPAT_KERNEL_HWCAP(THUMB)] = "thumb",
141 [COMPAT_KERNEL_HWCAP(26BIT)] = NULL, /* Not possible on arm64 */
142 [COMPAT_KERNEL_HWCAP(FAST_MULT)] = "fastmult",
143 [COMPAT_KERNEL_HWCAP(FPA)] = NULL, /* Not possible on arm64 */
144 [COMPAT_KERNEL_HWCAP(VFP)] = "vfp",
145 [COMPAT_KERNEL_HWCAP(EDSP)] = "edsp",
146 [COMPAT_KERNEL_HWCAP(JAVA)] = NULL, /* Not possible on arm64 */
147 [COMPAT_KERNEL_HWCAP(IWMMXT)] = NULL, /* Not possible on arm64 */
148 [COMPAT_KERNEL_HWCAP(CRUNCH)] = NULL, /* Not possible on arm64 */
149 [COMPAT_KERNEL_HWCAP(THUMBEE)] = NULL, /* Not possible on arm64 */
150 [COMPAT_KERNEL_HWCAP(NEON)] = "neon",
151 [COMPAT_KERNEL_HWCAP(VFPv3)] = "vfpv3",
152 [COMPAT_KERNEL_HWCAP(VFPV3D16)] = NULL, /* Not possible on arm64 */
153 [COMPAT_KERNEL_HWCAP(TLS)] = "tls",
154 [COMPAT_KERNEL_HWCAP(VFPv4)] = "vfpv4",
155 [COMPAT_KERNEL_HWCAP(IDIVA)] = "idiva",
156 [COMPAT_KERNEL_HWCAP(IDIVT)] = "idivt",
157 [COMPAT_KERNEL_HWCAP(VFPD32)] = NULL, /* Not possible on arm64 */
158 [COMPAT_KERNEL_HWCAP(LPAE)] = "lpae",
159 [COMPAT_KERNEL_HWCAP(EVTSTRM)] = "evtstrm",
160 [COMPAT_KERNEL_HWCAP(FPHP)] = "fphp",
161 [COMPAT_KERNEL_HWCAP(ASIMDHP)] = "asimdhp",
162 [COMPAT_KERNEL_HWCAP(ASIMDDP)] = "asimddp",
163 [COMPAT_KERNEL_HWCAP(ASIMDFHM)] = "asimdfhm",
164 [COMPAT_KERNEL_HWCAP(ASIMDBF16)] = "asimdbf16",
165 [COMPAT_KERNEL_HWCAP(I8MM)] = "i8mm",
168 #define COMPAT_KERNEL_HWCAP2(x) const_ilog2(COMPAT_HWCAP2_ ## x)
169 static const char *const compat_hwcap2_str[] = {
170 [COMPAT_KERNEL_HWCAP2(AES)] = "aes",
171 [COMPAT_KERNEL_HWCAP2(PMULL)] = "pmull",
172 [COMPAT_KERNEL_HWCAP2(SHA1)] = "sha1",
173 [COMPAT_KERNEL_HWCAP2(SHA2)] = "sha2",
174 [COMPAT_KERNEL_HWCAP2(CRC32)] = "crc32",
175 [COMPAT_KERNEL_HWCAP2(SB)] = "sb",
176 [COMPAT_KERNEL_HWCAP2(SSBS)] = "ssbs",
178 #endif /* CONFIG_COMPAT */
180 static int c_show(struct seq_file *m, void *v)
183 bool compat = personality(current->personality) == PER_LINUX32;
185 for_each_online_cpu(i) {
186 struct cpuinfo_arm64 *cpuinfo = &per_cpu(cpu_data, i);
187 u32 midr = cpuinfo->reg_midr;
190 * glibc reads /proc/cpuinfo to determine the number of
191 * online processors, looking for lines beginning with
192 * "processor". Give glibc what it expects.
194 seq_printf(m, "processor\t: %d\n", i);
196 seq_printf(m, "model name\t: ARMv8 Processor rev %d (%s)\n",
197 MIDR_REVISION(midr), COMPAT_ELF_PLATFORM);
199 seq_printf(m, "BogoMIPS\t: %lu.%02lu\n",
200 loops_per_jiffy / (500000UL/HZ),
201 loops_per_jiffy / (5000UL/HZ) % 100);
204 * Dump out the common processor features in a single line.
205 * Userspace should read the hwcaps with getauxval(AT_HWCAP)
206 * rather than attempting to parse this, but there's a body of
207 * software which does already (at least for 32-bit).
209 seq_puts(m, "Features\t:");
212 for (j = 0; j < ARRAY_SIZE(compat_hwcap_str); j++) {
213 if (compat_elf_hwcap & (1 << j)) {
215 * Warn once if any feature should not
216 * have been present on arm64 platform.
218 if (WARN_ON_ONCE(!compat_hwcap_str[j]))
221 seq_printf(m, " %s", compat_hwcap_str[j]);
225 for (j = 0; j < ARRAY_SIZE(compat_hwcap2_str); j++)
226 if (compat_elf_hwcap2 & (1 << j))
227 seq_printf(m, " %s", compat_hwcap2_str[j]);
228 #endif /* CONFIG_COMPAT */
230 for (j = 0; j < ARRAY_SIZE(hwcap_str); j++)
231 if (cpu_have_feature(j))
232 seq_printf(m, " %s", hwcap_str[j]);
236 seq_printf(m, "CPU implementer\t: 0x%02x\n",
237 MIDR_IMPLEMENTOR(midr));
238 seq_printf(m, "CPU architecture: 8\n");
239 seq_printf(m, "CPU variant\t: 0x%x\n", MIDR_VARIANT(midr));
240 seq_printf(m, "CPU part\t: 0x%03x\n", MIDR_PARTNUM(midr));
241 seq_printf(m, "CPU revision\t: %d\n\n", MIDR_REVISION(midr));
247 static void *c_start(struct seq_file *m, loff_t *pos)
249 return *pos < 1 ? (void *)1 : NULL;
252 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
258 static void c_stop(struct seq_file *m, void *v)
262 const struct seq_operations cpuinfo_op = {
270 static struct kobj_type cpuregs_kobj_type = {
271 .sysfs_ops = &kobj_sysfs_ops,
275 * The ARM ARM uses the phrase "32-bit register" to describe a register
276 * whose upper 32 bits are RES0 (per C5.1.1, ARM DDI 0487A.i), however
277 * no statement is made as to whether the upper 32 bits will or will not
278 * be made use of in future, and between ARM DDI 0487A.c and ARM DDI
279 * 0487A.d CLIDR_EL1 was expanded from 32-bit to 64-bit.
281 * Thus, while both MIDR_EL1 and REVIDR_EL1 are described as 32-bit
282 * registers, we expose them both as 64 bit values to cater for possible
283 * future expansion without an ABI break.
285 #define kobj_to_cpuinfo(kobj) container_of(kobj, struct cpuinfo_arm64, kobj)
286 #define CPUREGS_ATTR_RO(_name, _field) \
287 static ssize_t _name##_show(struct kobject *kobj, \
288 struct kobj_attribute *attr, char *buf) \
290 struct cpuinfo_arm64 *info = kobj_to_cpuinfo(kobj); \
292 if (info->reg_midr) \
293 return sprintf(buf, "0x%016llx\n", info->reg_##_field); \
297 static struct kobj_attribute cpuregs_attr_##_name = __ATTR_RO(_name)
299 CPUREGS_ATTR_RO(midr_el1, midr);
300 CPUREGS_ATTR_RO(revidr_el1, revidr);
301 CPUREGS_ATTR_RO(smidr_el1, smidr);
303 static struct attribute *cpuregs_id_attrs[] = {
304 &cpuregs_attr_midr_el1.attr,
305 &cpuregs_attr_revidr_el1.attr,
309 static const struct attribute_group cpuregs_attr_group = {
310 .attrs = cpuregs_id_attrs,
311 .name = "identification"
314 static struct attribute *sme_cpuregs_id_attrs[] = {
315 &cpuregs_attr_smidr_el1.attr,
319 static const struct attribute_group sme_cpuregs_attr_group = {
320 .attrs = sme_cpuregs_id_attrs,
321 .name = "identification"
324 static int cpuid_cpu_online(unsigned int cpu)
328 struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu);
330 dev = get_cpu_device(cpu);
335 rc = kobject_add(&info->kobj, &dev->kobj, "regs");
338 rc = sysfs_create_group(&info->kobj, &cpuregs_attr_group);
340 kobject_del(&info->kobj);
341 if (system_supports_sme())
342 rc = sysfs_merge_group(&info->kobj, &sme_cpuregs_attr_group);
347 static int cpuid_cpu_offline(unsigned int cpu)
350 struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu);
352 dev = get_cpu_device(cpu);
355 if (info->kobj.parent) {
356 sysfs_remove_group(&info->kobj, &cpuregs_attr_group);
357 kobject_del(&info->kobj);
363 static int __init cpuinfo_regs_init(void)
367 for_each_possible_cpu(cpu) {
368 struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu);
370 kobject_init(&info->kobj, &cpuregs_kobj_type);
373 ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "arm64/cpuinfo:online",
374 cpuid_cpu_online, cpuid_cpu_offline);
376 pr_err("cpuinfo: failed to register hotplug callbacks.\n");
381 device_initcall(cpuinfo_regs_init);
383 static void cpuinfo_detect_icache_policy(struct cpuinfo_arm64 *info)
385 unsigned int cpu = smp_processor_id();
386 u32 l1ip = CTR_L1IP(info->reg_ctr);
389 case CTR_EL0_L1Ip_PIPT:
391 case CTR_EL0_L1Ip_VPIPT:
392 set_bit(ICACHEF_VPIPT, &__icache_flags);
394 case CTR_EL0_L1Ip_VIPT:
396 /* Assume aliasing */
397 set_bit(ICACHEF_ALIASING, &__icache_flags);
401 pr_info("Detected %s I-cache on CPU%d\n", icache_policy_str(l1ip), cpu);
404 static void __cpuinfo_store_cpu_32bit(struct cpuinfo_32bit *info)
406 info->reg_id_dfr0 = read_cpuid(ID_DFR0_EL1);
407 info->reg_id_dfr1 = read_cpuid(ID_DFR1_EL1);
408 info->reg_id_isar0 = read_cpuid(ID_ISAR0_EL1);
409 info->reg_id_isar1 = read_cpuid(ID_ISAR1_EL1);
410 info->reg_id_isar2 = read_cpuid(ID_ISAR2_EL1);
411 info->reg_id_isar3 = read_cpuid(ID_ISAR3_EL1);
412 info->reg_id_isar4 = read_cpuid(ID_ISAR4_EL1);
413 info->reg_id_isar5 = read_cpuid(ID_ISAR5_EL1);
414 info->reg_id_isar6 = read_cpuid(ID_ISAR6_EL1);
415 info->reg_id_mmfr0 = read_cpuid(ID_MMFR0_EL1);
416 info->reg_id_mmfr1 = read_cpuid(ID_MMFR1_EL1);
417 info->reg_id_mmfr2 = read_cpuid(ID_MMFR2_EL1);
418 info->reg_id_mmfr3 = read_cpuid(ID_MMFR3_EL1);
419 info->reg_id_mmfr4 = read_cpuid(ID_MMFR4_EL1);
420 info->reg_id_mmfr5 = read_cpuid(ID_MMFR5_EL1);
421 info->reg_id_pfr0 = read_cpuid(ID_PFR0_EL1);
422 info->reg_id_pfr1 = read_cpuid(ID_PFR1_EL1);
423 info->reg_id_pfr2 = read_cpuid(ID_PFR2_EL1);
425 info->reg_mvfr0 = read_cpuid(MVFR0_EL1);
426 info->reg_mvfr1 = read_cpuid(MVFR1_EL1);
427 info->reg_mvfr2 = read_cpuid(MVFR2_EL1);
430 static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info)
432 info->reg_cntfrq = arch_timer_get_cntfrq();
434 * Use the effective value of the CTR_EL0 than the raw value
435 * exposed by the CPU. CTR_EL0.IDC field value must be interpreted
436 * with the CLIDR_EL1 fields to avoid triggering false warnings
437 * when there is a mismatch across the CPUs. Keep track of the
438 * effective value of the CTR_EL0 in our internal records for
439 * accurate sanity check and feature enablement.
441 info->reg_ctr = read_cpuid_effective_cachetype();
442 info->reg_dczid = read_cpuid(DCZID_EL0);
443 info->reg_midr = read_cpuid_id();
444 info->reg_revidr = read_cpuid(REVIDR_EL1);
446 info->reg_id_aa64dfr0 = read_cpuid(ID_AA64DFR0_EL1);
447 info->reg_id_aa64dfr1 = read_cpuid(ID_AA64DFR1_EL1);
448 info->reg_id_aa64isar0 = read_cpuid(ID_AA64ISAR0_EL1);
449 info->reg_id_aa64isar1 = read_cpuid(ID_AA64ISAR1_EL1);
450 info->reg_id_aa64isar2 = read_cpuid(ID_AA64ISAR2_EL1);
451 info->reg_id_aa64mmfr0 = read_cpuid(ID_AA64MMFR0_EL1);
452 info->reg_id_aa64mmfr1 = read_cpuid(ID_AA64MMFR1_EL1);
453 info->reg_id_aa64mmfr2 = read_cpuid(ID_AA64MMFR2_EL1);
454 info->reg_id_aa64mmfr3 = read_cpuid(ID_AA64MMFR3_EL1);
455 info->reg_id_aa64pfr0 = read_cpuid(ID_AA64PFR0_EL1);
456 info->reg_id_aa64pfr1 = read_cpuid(ID_AA64PFR1_EL1);
457 info->reg_id_aa64zfr0 = read_cpuid(ID_AA64ZFR0_EL1);
458 info->reg_id_aa64smfr0 = read_cpuid(ID_AA64SMFR0_EL1);
460 if (id_aa64pfr1_mte(info->reg_id_aa64pfr1))
461 info->reg_gmid = read_cpuid(GMID_EL1);
463 if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0))
464 __cpuinfo_store_cpu_32bit(&info->aarch32);
466 cpuinfo_detect_icache_policy(info);
469 void cpuinfo_store_cpu(void)
471 struct cpuinfo_arm64 *info = this_cpu_ptr(&cpu_data);
472 __cpuinfo_store_cpu(info);
473 update_cpu_features(smp_processor_id(), info, &boot_cpu_data);
476 void __init cpuinfo_store_boot_cpu(void)
478 struct cpuinfo_arm64 *info = &per_cpu(cpu_data, 0);
479 __cpuinfo_store_cpu(info);
481 boot_cpu_data = *info;
482 init_cpu_features(&boot_cpu_data);