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
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>
27
28 /*
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.
32 */
33 DEFINE_PER_CPU(struct cpuinfo_arm64, cpu_data);
34 static struct cpuinfo_arm64 boot_cpu_data;
35
36 static const char *icache_policy_str[] = {
37 [ICACHE_POLICY_VPIPT] = "VPIPT",
38 [ICACHE_POLICY_RESERVED] = "RESERVED/UNKNOWN",
39 [ICACHE_POLICY_VIPT] = "VIPT",
40 [ICACHE_POLICY_PIPT] = "PIPT",
41 };
42
43 unsigned long __icache_flags;
44
45 static const char *const hwcap_str[] = {
46 [KERNEL_HWCAP_FP] = "fp",
47 [KERNEL_HWCAP_ASIMD] = "asimd",
48 [KERNEL_HWCAP_EVTSTRM] = "evtstrm",
49 [KERNEL_HWCAP_AES] = "aes",
50 [KERNEL_HWCAP_PMULL] = "pmull",
51 [KERNEL_HWCAP_SHA1] = "sha1",
52 [KERNEL_HWCAP_SHA2] = "sha2",
53 [KERNEL_HWCAP_CRC32] = "crc32",
54 [KERNEL_HWCAP_ATOMICS] = "atomics",
55 [KERNEL_HWCAP_FPHP] = "fphp",
56 [KERNEL_HWCAP_ASIMDHP] = "asimdhp",
57 [KERNEL_HWCAP_CPUID] = "cpuid",
58 [KERNEL_HWCAP_ASIMDRDM] = "asimdrdm",
59 [KERNEL_HWCAP_JSCVT] = "jscvt",
60 [KERNEL_HWCAP_FCMA] = "fcma",
61 [KERNEL_HWCAP_LRCPC] = "lrcpc",
62 [KERNEL_HWCAP_DCPOP] = "dcpop",
63 [KERNEL_HWCAP_SHA3] = "sha3",
64 [KERNEL_HWCAP_SM3] = "sm3",
65 [KERNEL_HWCAP_SM4] = "sm4",
66 [KERNEL_HWCAP_ASIMDDP] = "asimddp",
67 [KERNEL_HWCAP_SHA512] = "sha512",
68 [KERNEL_HWCAP_SVE] = "sve",
69 [KERNEL_HWCAP_ASIMDFHM] = "asimdfhm",
70 [KERNEL_HWCAP_DIT] = "dit",
71 [KERNEL_HWCAP_USCAT] = "uscat",
72 [KERNEL_HWCAP_ILRCPC] = "ilrcpc",
73 [KERNEL_HWCAP_FLAGM] = "flagm",
74 [KERNEL_HWCAP_SSBS] = "ssbs",
75 [KERNEL_HWCAP_SB] = "sb",
76 [KERNEL_HWCAP_PACA] = "paca",
77 [KERNEL_HWCAP_PACG] = "pacg",
78 [KERNEL_HWCAP_DCPODP] = "dcpodp",
79 [KERNEL_HWCAP_SVE2] = "sve2",
80 [KERNEL_HWCAP_SVEAES] = "sveaes",
81 [KERNEL_HWCAP_SVEPMULL] = "svepmull",
82 [KERNEL_HWCAP_SVEBITPERM] = "svebitperm",
83 [KERNEL_HWCAP_SVESHA3] = "svesha3",
84 [KERNEL_HWCAP_SVESM4] = "svesm4",
85 [KERNEL_HWCAP_FLAGM2] = "flagm2",
86 [KERNEL_HWCAP_FRINT] = "frint",
87 [KERNEL_HWCAP_SVEI8MM] = "svei8mm",
88 [KERNEL_HWCAP_SVEF32MM] = "svef32mm",
89 [KERNEL_HWCAP_SVEF64MM] = "svef64mm",
90 [KERNEL_HWCAP_SVEBF16] = "svebf16",
91 [KERNEL_HWCAP_I8MM] = "i8mm",
92 [KERNEL_HWCAP_BF16] = "bf16",
93 [KERNEL_HWCAP_DGH] = "dgh",
94 [KERNEL_HWCAP_RNG] = "rng",
95 [KERNEL_HWCAP_BTI] = "bti",
96 [KERNEL_HWCAP_MTE] = "mte",
97 [KERNEL_HWCAP_ECV] = "ecv",
98 [KERNEL_HWCAP_AFP] = "afp",
99 [KERNEL_HWCAP_RPRES] = "rpres",
100 };
101
102 #ifdef CONFIG_COMPAT
103 #define COMPAT_KERNEL_HWCAP(x) const_ilog2(COMPAT_HWCAP_ ## x)
104 static const char *const compat_hwcap_str[] = {
105 [COMPAT_KERNEL_HWCAP(SWP)] = "swp",
106 [COMPAT_KERNEL_HWCAP(HALF)] = "half",
107 [COMPAT_KERNEL_HWCAP(THUMB)] = "thumb",
108 [COMPAT_KERNEL_HWCAP(26BIT)] = NULL, /* Not possible on arm64 */
109 [COMPAT_KERNEL_HWCAP(FAST_MULT)] = "fastmult",
110 [COMPAT_KERNEL_HWCAP(FPA)] = NULL, /* Not possible on arm64 */
111 [COMPAT_KERNEL_HWCAP(VFP)] = "vfp",
112 [COMPAT_KERNEL_HWCAP(EDSP)] = "edsp",
113 [COMPAT_KERNEL_HWCAP(JAVA)] = NULL, /* Not possible on arm64 */
114 [COMPAT_KERNEL_HWCAP(IWMMXT)] = NULL, /* Not possible on arm64 */
115 [COMPAT_KERNEL_HWCAP(CRUNCH)] = NULL, /* Not possible on arm64 */
116 [COMPAT_KERNEL_HWCAP(THUMBEE)] = NULL, /* Not possible on arm64 */
117 [COMPAT_KERNEL_HWCAP(NEON)] = "neon",
118 [COMPAT_KERNEL_HWCAP(VFPv3)] = "vfpv3",
119 [COMPAT_KERNEL_HWCAP(VFPV3D16)] = NULL, /* Not possible on arm64 */
120 [COMPAT_KERNEL_HWCAP(TLS)] = "tls",
121 [COMPAT_KERNEL_HWCAP(VFPv4)] = "vfpv4",
122 [COMPAT_KERNEL_HWCAP(IDIVA)] = "idiva",
123 [COMPAT_KERNEL_HWCAP(IDIVT)] = "idivt",
124 [COMPAT_KERNEL_HWCAP(VFPD32)] = NULL, /* Not possible on arm64 */
125 [COMPAT_KERNEL_HWCAP(LPAE)] = "lpae",
126 [COMPAT_KERNEL_HWCAP(EVTSTRM)] = "evtstrm",
127 };
128
129 #define COMPAT_KERNEL_HWCAP2(x) const_ilog2(COMPAT_HWCAP2_ ## x)
130 static const char *const compat_hwcap2_str[] = {
131 [COMPAT_KERNEL_HWCAP2(AES)] = "aes",
132 [COMPAT_KERNEL_HWCAP2(PMULL)] = "pmull",
133 [COMPAT_KERNEL_HWCAP2(SHA1)] = "sha1",
134 [COMPAT_KERNEL_HWCAP2(SHA2)] = "sha2",
135 [COMPAT_KERNEL_HWCAP2(CRC32)] = "crc32",
136 };
137 #endif /* CONFIG_COMPAT */
138
c_show(struct seq_file * m,void * v)139 static int c_show(struct seq_file *m, void *v)
140 {
141 int i, j;
142 bool compat = personality(current->personality) == PER_LINUX32;
143
144 for_each_online_cpu(i) {
145 struct cpuinfo_arm64 *cpuinfo = &per_cpu(cpu_data, i);
146 u32 midr = cpuinfo->reg_midr;
147
148 /*
149 * glibc reads /proc/cpuinfo to determine the number of
150 * online processors, looking for lines beginning with
151 * "processor". Give glibc what it expects.
152 */
153 seq_printf(m, "processor\t: %d\n", i);
154 if (compat)
155 seq_printf(m, "model name\t: ARMv8 Processor rev %d (%s)\n",
156 MIDR_REVISION(midr), COMPAT_ELF_PLATFORM);
157
158 seq_printf(m, "BogoMIPS\t: %lu.%02lu\n",
159 loops_per_jiffy / (500000UL/HZ),
160 loops_per_jiffy / (5000UL/HZ) % 100);
161
162 /*
163 * Dump out the common processor features in a single line.
164 * Userspace should read the hwcaps with getauxval(AT_HWCAP)
165 * rather than attempting to parse this, but there's a body of
166 * software which does already (at least for 32-bit).
167 */
168 seq_puts(m, "Features\t:");
169 if (compat) {
170 #ifdef CONFIG_COMPAT
171 for (j = 0; j < ARRAY_SIZE(compat_hwcap_str); j++) {
172 if (compat_elf_hwcap & (1 << j)) {
173 /*
174 * Warn once if any feature should not
175 * have been present on arm64 platform.
176 */
177 if (WARN_ON_ONCE(!compat_hwcap_str[j]))
178 continue;
179
180 seq_printf(m, " %s", compat_hwcap_str[j]);
181 }
182 }
183
184 for (j = 0; j < ARRAY_SIZE(compat_hwcap2_str); j++)
185 if (compat_elf_hwcap2 & (1 << j))
186 seq_printf(m, " %s", compat_hwcap2_str[j]);
187 #endif /* CONFIG_COMPAT */
188 } else {
189 for (j = 0; j < ARRAY_SIZE(hwcap_str); j++)
190 if (cpu_have_feature(j))
191 seq_printf(m, " %s", hwcap_str[j]);
192 }
193 seq_puts(m, "\n");
194
195 seq_printf(m, "CPU implementer\t: 0x%02x\n",
196 MIDR_IMPLEMENTOR(midr));
197 seq_printf(m, "CPU architecture: 8\n");
198 seq_printf(m, "CPU variant\t: 0x%x\n", MIDR_VARIANT(midr));
199 seq_printf(m, "CPU part\t: 0x%03x\n", MIDR_PARTNUM(midr));
200 seq_printf(m, "CPU revision\t: %d\n\n", MIDR_REVISION(midr));
201 }
202
203 return 0;
204 }
205
c_start(struct seq_file * m,loff_t * pos)206 static void *c_start(struct seq_file *m, loff_t *pos)
207 {
208 return *pos < 1 ? (void *)1 : NULL;
209 }
210
c_next(struct seq_file * m,void * v,loff_t * pos)211 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
212 {
213 ++*pos;
214 return NULL;
215 }
216
c_stop(struct seq_file * m,void * v)217 static void c_stop(struct seq_file *m, void *v)
218 {
219 }
220
221 const struct seq_operations cpuinfo_op = {
222 .start = c_start,
223 .next = c_next,
224 .stop = c_stop,
225 .show = c_show
226 };
227
228
229 static struct kobj_type cpuregs_kobj_type = {
230 .sysfs_ops = &kobj_sysfs_ops,
231 };
232
233 /*
234 * The ARM ARM uses the phrase "32-bit register" to describe a register
235 * whose upper 32 bits are RES0 (per C5.1.1, ARM DDI 0487A.i), however
236 * no statement is made as to whether the upper 32 bits will or will not
237 * be made use of in future, and between ARM DDI 0487A.c and ARM DDI
238 * 0487A.d CLIDR_EL1 was expanded from 32-bit to 64-bit.
239 *
240 * Thus, while both MIDR_EL1 and REVIDR_EL1 are described as 32-bit
241 * registers, we expose them both as 64 bit values to cater for possible
242 * future expansion without an ABI break.
243 */
244 #define kobj_to_cpuinfo(kobj) container_of(kobj, struct cpuinfo_arm64, kobj)
245 #define CPUREGS_ATTR_RO(_name, _field) \
246 static ssize_t _name##_show(struct kobject *kobj, \
247 struct kobj_attribute *attr, char *buf) \
248 { \
249 struct cpuinfo_arm64 *info = kobj_to_cpuinfo(kobj); \
250 \
251 if (info->reg_midr) \
252 return sprintf(buf, "0x%016x\n", info->reg_##_field); \
253 else \
254 return 0; \
255 } \
256 static struct kobj_attribute cpuregs_attr_##_name = __ATTR_RO(_name)
257
258 CPUREGS_ATTR_RO(midr_el1, midr);
259 CPUREGS_ATTR_RO(revidr_el1, revidr);
260
261 static struct attribute *cpuregs_id_attrs[] = {
262 &cpuregs_attr_midr_el1.attr,
263 &cpuregs_attr_revidr_el1.attr,
264 NULL
265 };
266
267 static const struct attribute_group cpuregs_attr_group = {
268 .attrs = cpuregs_id_attrs,
269 .name = "identification"
270 };
271
cpuid_cpu_online(unsigned int cpu)272 static int cpuid_cpu_online(unsigned int cpu)
273 {
274 int rc;
275 struct device *dev;
276 struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu);
277
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 out:
290 return rc;
291 }
292
cpuid_cpu_offline(unsigned int cpu)293 static int cpuid_cpu_offline(unsigned int cpu)
294 {
295 struct device *dev;
296 struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu);
297
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
306 return 0;
307 }
308
cpuinfo_regs_init(void)309 static int __init cpuinfo_regs_init(void)
310 {
311 int cpu, ret;
312
313 for_each_possible_cpu(cpu) {
314 struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu);
315
316 kobject_init(&info->kobj, &cpuregs_kobj_type);
317 }
318
319 ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "arm64/cpuinfo:online",
320 cpuid_cpu_online, cpuid_cpu_offline);
321 if (ret < 0) {
322 pr_err("cpuinfo: failed to register hotplug callbacks.\n");
323 return ret;
324 }
325 return 0;
326 }
327 device_initcall(cpuinfo_regs_init);
328
cpuinfo_detect_icache_policy(struct cpuinfo_arm64 * info)329 static void cpuinfo_detect_icache_policy(struct cpuinfo_arm64 *info)
330 {
331 unsigned int cpu = smp_processor_id();
332 u32 l1ip = CTR_L1IP(info->reg_ctr);
333
334 switch (l1ip) {
335 case ICACHE_POLICY_PIPT:
336 break;
337 case ICACHE_POLICY_VPIPT:
338 set_bit(ICACHEF_VPIPT, &__icache_flags);
339 break;
340 case ICACHE_POLICY_RESERVED:
341 case ICACHE_POLICY_VIPT:
342 /* Assume aliasing */
343 set_bit(ICACHEF_ALIASING, &__icache_flags);
344 break;
345 }
346
347 pr_info("Detected %s I-cache on CPU%d\n", icache_policy_str[l1ip], cpu);
348 }
349
__cpuinfo_store_cpu(struct cpuinfo_arm64 * info)350 static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info)
351 {
352 info->reg_cntfrq = arch_timer_get_cntfrq();
353 /*
354 * Use the effective value of the CTR_EL0 than the raw value
355 * exposed by the CPU. CTR_EL0.IDC field value must be interpreted
356 * with the CLIDR_EL1 fields to avoid triggering false warnings
357 * when there is a mismatch across the CPUs. Keep track of the
358 * effective value of the CTR_EL0 in our internal records for
359 * acurate sanity check and feature enablement.
360 */
361 info->reg_ctr = read_cpuid_effective_cachetype();
362 info->reg_dczid = read_cpuid(DCZID_EL0);
363 info->reg_midr = read_cpuid_id();
364 info->reg_revidr = read_cpuid(REVIDR_EL1);
365
366 info->reg_id_aa64dfr0 = read_cpuid(ID_AA64DFR0_EL1);
367 info->reg_id_aa64dfr1 = read_cpuid(ID_AA64DFR1_EL1);
368 info->reg_id_aa64isar0 = read_cpuid(ID_AA64ISAR0_EL1);
369 info->reg_id_aa64isar1 = read_cpuid(ID_AA64ISAR1_EL1);
370 info->reg_id_aa64isar2 = read_cpuid(ID_AA64ISAR2_EL1);
371 info->reg_id_aa64mmfr0 = read_cpuid(ID_AA64MMFR0_EL1);
372 info->reg_id_aa64mmfr1 = read_cpuid(ID_AA64MMFR1_EL1);
373 info->reg_id_aa64mmfr2 = read_cpuid(ID_AA64MMFR2_EL1);
374 info->reg_id_aa64pfr0 = read_cpuid(ID_AA64PFR0_EL1);
375 info->reg_id_aa64pfr1 = read_cpuid(ID_AA64PFR1_EL1);
376 info->reg_id_aa64zfr0 = read_cpuid(ID_AA64ZFR0_EL1);
377
378 /* Update the 32bit ID registers only if AArch32 is implemented */
379 if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0)) {
380 info->reg_id_dfr0 = read_cpuid(ID_DFR0_EL1);
381 info->reg_id_dfr1 = read_cpuid(ID_DFR1_EL1);
382 info->reg_id_isar0 = read_cpuid(ID_ISAR0_EL1);
383 info->reg_id_isar1 = read_cpuid(ID_ISAR1_EL1);
384 info->reg_id_isar2 = read_cpuid(ID_ISAR2_EL1);
385 info->reg_id_isar3 = read_cpuid(ID_ISAR3_EL1);
386 info->reg_id_isar4 = read_cpuid(ID_ISAR4_EL1);
387 info->reg_id_isar5 = read_cpuid(ID_ISAR5_EL1);
388 info->reg_id_isar6 = read_cpuid(ID_ISAR6_EL1);
389 info->reg_id_mmfr0 = read_cpuid(ID_MMFR0_EL1);
390 info->reg_id_mmfr1 = read_cpuid(ID_MMFR1_EL1);
391 info->reg_id_mmfr2 = read_cpuid(ID_MMFR2_EL1);
392 info->reg_id_mmfr3 = read_cpuid(ID_MMFR3_EL1);
393 info->reg_id_mmfr4 = read_cpuid(ID_MMFR4_EL1);
394 info->reg_id_mmfr5 = read_cpuid(ID_MMFR5_EL1);
395 info->reg_id_pfr0 = read_cpuid(ID_PFR0_EL1);
396 info->reg_id_pfr1 = read_cpuid(ID_PFR1_EL1);
397 info->reg_id_pfr2 = read_cpuid(ID_PFR2_EL1);
398
399 info->reg_mvfr0 = read_cpuid(MVFR0_EL1);
400 info->reg_mvfr1 = read_cpuid(MVFR1_EL1);
401 info->reg_mvfr2 = read_cpuid(MVFR2_EL1);
402 }
403
404 if (IS_ENABLED(CONFIG_ARM64_SVE) &&
405 id_aa64pfr0_sve(info->reg_id_aa64pfr0))
406 info->reg_zcr = read_zcr_features();
407
408 cpuinfo_detect_icache_policy(info);
409 }
410
cpuinfo_store_cpu(void)411 void cpuinfo_store_cpu(void)
412 {
413 struct cpuinfo_arm64 *info = this_cpu_ptr(&cpu_data);
414 __cpuinfo_store_cpu(info);
415 update_cpu_features(smp_processor_id(), info, &boot_cpu_data);
416 }
417
cpuinfo_store_boot_cpu(void)418 void __init cpuinfo_store_boot_cpu(void)
419 {
420 struct cpuinfo_arm64 *info = &per_cpu(cpu_data, 0);
421 __cpuinfo_store_cpu(info);
422
423 boot_cpu_data = *info;
424 init_cpu_features(&boot_cpu_data);
425 }
426