1 /* 2 * Record and handle CPU attributes. 3 * 4 * Copyright (C) 2014 ARM Ltd. 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program. If not, see <http://www.gnu.org/licenses/>. 16 */ 17 #include <asm/arch_timer.h> 18 #include <asm/cache.h> 19 #include <asm/cpu.h> 20 #include <asm/cputype.h> 21 #include <asm/cpufeature.h> 22 23 #include <linux/bitops.h> 24 #include <linux/bug.h> 25 #include <linux/compat.h> 26 #include <linux/elf.h> 27 #include <linux/init.h> 28 #include <linux/kernel.h> 29 #include <linux/personality.h> 30 #include <linux/preempt.h> 31 #include <linux/printk.h> 32 #include <linux/seq_file.h> 33 #include <linux/sched.h> 34 #include <linux/smp.h> 35 #include <linux/delay.h> 36 37 /* 38 * In case the boot CPU is hotpluggable, we record its initial state and 39 * current state separately. Certain system registers may contain different 40 * values depending on configuration at or after reset. 41 */ 42 DEFINE_PER_CPU(struct cpuinfo_arm64, cpu_data); 43 static struct cpuinfo_arm64 boot_cpu_data; 44 45 static char *icache_policy_str[] = { 46 [0 ... ICACHE_POLICY_PIPT] = "RESERVED/UNKNOWN", 47 [ICACHE_POLICY_VIPT] = "VIPT", 48 [ICACHE_POLICY_PIPT] = "PIPT", 49 [ICACHE_POLICY_VPIPT] = "VPIPT", 50 }; 51 52 unsigned long __icache_flags; 53 54 static const char *const hwcap_str[] = { 55 "fp", 56 "asimd", 57 "evtstrm", 58 "aes", 59 "pmull", 60 "sha1", 61 "sha2", 62 "crc32", 63 "atomics", 64 "fphp", 65 "asimdhp", 66 "cpuid", 67 "asimdrdm", 68 "jscvt", 69 "fcma", 70 "lrcpc", 71 NULL 72 }; 73 74 #ifdef CONFIG_COMPAT 75 static const char *const compat_hwcap_str[] = { 76 "swp", 77 "half", 78 "thumb", 79 "26bit", 80 "fastmult", 81 "fpa", 82 "vfp", 83 "edsp", 84 "java", 85 "iwmmxt", 86 "crunch", 87 "thumbee", 88 "neon", 89 "vfpv3", 90 "vfpv3d16", 91 "tls", 92 "vfpv4", 93 "idiva", 94 "idivt", 95 "vfpd32", 96 "lpae", 97 "evtstrm", 98 NULL 99 }; 100 101 static const char *const compat_hwcap2_str[] = { 102 "aes", 103 "pmull", 104 "sha1", 105 "sha2", 106 "crc32", 107 NULL 108 }; 109 #endif /* CONFIG_COMPAT */ 110 111 static int c_show(struct seq_file *m, void *v) 112 { 113 int i, j; 114 bool compat = personality(current->personality) == PER_LINUX32; 115 116 for_each_online_cpu(i) { 117 struct cpuinfo_arm64 *cpuinfo = &per_cpu(cpu_data, i); 118 u32 midr = cpuinfo->reg_midr; 119 120 /* 121 * glibc reads /proc/cpuinfo to determine the number of 122 * online processors, looking for lines beginning with 123 * "processor". Give glibc what it expects. 124 */ 125 seq_printf(m, "processor\t: %d\n", i); 126 if (compat) 127 seq_printf(m, "model name\t: ARMv8 Processor rev %d (%s)\n", 128 MIDR_REVISION(midr), COMPAT_ELF_PLATFORM); 129 130 seq_printf(m, "BogoMIPS\t: %lu.%02lu\n", 131 loops_per_jiffy / (500000UL/HZ), 132 loops_per_jiffy / (5000UL/HZ) % 100); 133 134 /* 135 * Dump out the common processor features in a single line. 136 * Userspace should read the hwcaps with getauxval(AT_HWCAP) 137 * rather than attempting to parse this, but there's a body of 138 * software which does already (at least for 32-bit). 139 */ 140 seq_puts(m, "Features\t:"); 141 if (compat) { 142 #ifdef CONFIG_COMPAT 143 for (j = 0; compat_hwcap_str[j]; j++) 144 if (compat_elf_hwcap & (1 << j)) 145 seq_printf(m, " %s", compat_hwcap_str[j]); 146 147 for (j = 0; compat_hwcap2_str[j]; j++) 148 if (compat_elf_hwcap2 & (1 << j)) 149 seq_printf(m, " %s", compat_hwcap2_str[j]); 150 #endif /* CONFIG_COMPAT */ 151 } else { 152 for (j = 0; hwcap_str[j]; j++) 153 if (elf_hwcap & (1 << j)) 154 seq_printf(m, " %s", hwcap_str[j]); 155 } 156 seq_puts(m, "\n"); 157 158 seq_printf(m, "CPU implementer\t: 0x%02x\n", 159 MIDR_IMPLEMENTOR(midr)); 160 seq_printf(m, "CPU architecture: 8\n"); 161 seq_printf(m, "CPU variant\t: 0x%x\n", MIDR_VARIANT(midr)); 162 seq_printf(m, "CPU part\t: 0x%03x\n", MIDR_PARTNUM(midr)); 163 seq_printf(m, "CPU revision\t: %d\n\n", MIDR_REVISION(midr)); 164 } 165 166 return 0; 167 } 168 169 static void *c_start(struct seq_file *m, loff_t *pos) 170 { 171 return *pos < 1 ? (void *)1 : NULL; 172 } 173 174 static void *c_next(struct seq_file *m, void *v, loff_t *pos) 175 { 176 ++*pos; 177 return NULL; 178 } 179 180 static void c_stop(struct seq_file *m, void *v) 181 { 182 } 183 184 const struct seq_operations cpuinfo_op = { 185 .start = c_start, 186 .next = c_next, 187 .stop = c_stop, 188 .show = c_show 189 }; 190 191 192 static struct kobj_type cpuregs_kobj_type = { 193 .sysfs_ops = &kobj_sysfs_ops, 194 }; 195 196 /* 197 * The ARM ARM uses the phrase "32-bit register" to describe a register 198 * whose upper 32 bits are RES0 (per C5.1.1, ARM DDI 0487A.i), however 199 * no statement is made as to whether the upper 32 bits will or will not 200 * be made use of in future, and between ARM DDI 0487A.c and ARM DDI 201 * 0487A.d CLIDR_EL1 was expanded from 32-bit to 64-bit. 202 * 203 * Thus, while both MIDR_EL1 and REVIDR_EL1 are described as 32-bit 204 * registers, we expose them both as 64 bit values to cater for possible 205 * future expansion without an ABI break. 206 */ 207 #define kobj_to_cpuinfo(kobj) container_of(kobj, struct cpuinfo_arm64, kobj) 208 #define CPUREGS_ATTR_RO(_name, _field) \ 209 static ssize_t _name##_show(struct kobject *kobj, \ 210 struct kobj_attribute *attr, char *buf) \ 211 { \ 212 struct cpuinfo_arm64 *info = kobj_to_cpuinfo(kobj); \ 213 \ 214 if (info->reg_midr) \ 215 return sprintf(buf, "0x%016x\n", info->reg_##_field); \ 216 else \ 217 return 0; \ 218 } \ 219 static struct kobj_attribute cpuregs_attr_##_name = __ATTR_RO(_name) 220 221 CPUREGS_ATTR_RO(midr_el1, midr); 222 CPUREGS_ATTR_RO(revidr_el1, revidr); 223 224 static struct attribute *cpuregs_id_attrs[] = { 225 &cpuregs_attr_midr_el1.attr, 226 &cpuregs_attr_revidr_el1.attr, 227 NULL 228 }; 229 230 static struct attribute_group cpuregs_attr_group = { 231 .attrs = cpuregs_id_attrs, 232 .name = "identification" 233 }; 234 235 static int cpuid_cpu_online(unsigned int cpu) 236 { 237 int rc; 238 struct device *dev; 239 struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu); 240 241 dev = get_cpu_device(cpu); 242 if (!dev) { 243 rc = -ENODEV; 244 goto out; 245 } 246 rc = kobject_add(&info->kobj, &dev->kobj, "regs"); 247 if (rc) 248 goto out; 249 rc = sysfs_create_group(&info->kobj, &cpuregs_attr_group); 250 if (rc) 251 kobject_del(&info->kobj); 252 out: 253 return rc; 254 } 255 256 static int cpuid_cpu_offline(unsigned int cpu) 257 { 258 struct device *dev; 259 struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu); 260 261 dev = get_cpu_device(cpu); 262 if (!dev) 263 return -ENODEV; 264 if (info->kobj.parent) { 265 sysfs_remove_group(&info->kobj, &cpuregs_attr_group); 266 kobject_del(&info->kobj); 267 } 268 269 return 0; 270 } 271 272 static int __init cpuinfo_regs_init(void) 273 { 274 int cpu, ret; 275 276 for_each_possible_cpu(cpu) { 277 struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu); 278 279 kobject_init(&info->kobj, &cpuregs_kobj_type); 280 } 281 282 ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "arm64/cpuinfo:online", 283 cpuid_cpu_online, cpuid_cpu_offline); 284 if (ret < 0) { 285 pr_err("cpuinfo: failed to register hotplug callbacks.\n"); 286 return ret; 287 } 288 return 0; 289 } 290 static void cpuinfo_detect_icache_policy(struct cpuinfo_arm64 *info) 291 { 292 unsigned int cpu = smp_processor_id(); 293 u32 l1ip = CTR_L1IP(info->reg_ctr); 294 295 switch (l1ip) { 296 case ICACHE_POLICY_PIPT: 297 break; 298 case ICACHE_POLICY_VPIPT: 299 set_bit(ICACHEF_VPIPT, &__icache_flags); 300 break; 301 default: 302 /* Fallthrough */ 303 case ICACHE_POLICY_VIPT: 304 /* Assume aliasing */ 305 set_bit(ICACHEF_ALIASING, &__icache_flags); 306 } 307 308 pr_info("Detected %s I-cache on CPU%d\n", icache_policy_str[l1ip], cpu); 309 } 310 311 static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info) 312 { 313 info->reg_cntfrq = arch_timer_get_cntfrq(); 314 info->reg_ctr = read_cpuid_cachetype(); 315 info->reg_dczid = read_cpuid(DCZID_EL0); 316 info->reg_midr = read_cpuid_id(); 317 info->reg_revidr = read_cpuid(REVIDR_EL1); 318 319 info->reg_id_aa64dfr0 = read_cpuid(ID_AA64DFR0_EL1); 320 info->reg_id_aa64dfr1 = read_cpuid(ID_AA64DFR1_EL1); 321 info->reg_id_aa64isar0 = read_cpuid(ID_AA64ISAR0_EL1); 322 info->reg_id_aa64isar1 = read_cpuid(ID_AA64ISAR1_EL1); 323 info->reg_id_aa64mmfr0 = read_cpuid(ID_AA64MMFR0_EL1); 324 info->reg_id_aa64mmfr1 = read_cpuid(ID_AA64MMFR1_EL1); 325 info->reg_id_aa64mmfr2 = read_cpuid(ID_AA64MMFR2_EL1); 326 info->reg_id_aa64pfr0 = read_cpuid(ID_AA64PFR0_EL1); 327 info->reg_id_aa64pfr1 = read_cpuid(ID_AA64PFR1_EL1); 328 329 /* Update the 32bit ID registers only if AArch32 is implemented */ 330 if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0)) { 331 info->reg_id_dfr0 = read_cpuid(ID_DFR0_EL1); 332 info->reg_id_isar0 = read_cpuid(ID_ISAR0_EL1); 333 info->reg_id_isar1 = read_cpuid(ID_ISAR1_EL1); 334 info->reg_id_isar2 = read_cpuid(ID_ISAR2_EL1); 335 info->reg_id_isar3 = read_cpuid(ID_ISAR3_EL1); 336 info->reg_id_isar4 = read_cpuid(ID_ISAR4_EL1); 337 info->reg_id_isar5 = read_cpuid(ID_ISAR5_EL1); 338 info->reg_id_mmfr0 = read_cpuid(ID_MMFR0_EL1); 339 info->reg_id_mmfr1 = read_cpuid(ID_MMFR1_EL1); 340 info->reg_id_mmfr2 = read_cpuid(ID_MMFR2_EL1); 341 info->reg_id_mmfr3 = read_cpuid(ID_MMFR3_EL1); 342 info->reg_id_pfr0 = read_cpuid(ID_PFR0_EL1); 343 info->reg_id_pfr1 = read_cpuid(ID_PFR1_EL1); 344 345 info->reg_mvfr0 = read_cpuid(MVFR0_EL1); 346 info->reg_mvfr1 = read_cpuid(MVFR1_EL1); 347 info->reg_mvfr2 = read_cpuid(MVFR2_EL1); 348 } 349 350 cpuinfo_detect_icache_policy(info); 351 } 352 353 void cpuinfo_store_cpu(void) 354 { 355 struct cpuinfo_arm64 *info = this_cpu_ptr(&cpu_data); 356 __cpuinfo_store_cpu(info); 357 update_cpu_features(smp_processor_id(), info, &boot_cpu_data); 358 } 359 360 void __init cpuinfo_store_boot_cpu(void) 361 { 362 struct cpuinfo_arm64 *info = &per_cpu(cpu_data, 0); 363 __cpuinfo_store_cpu(info); 364 365 boot_cpu_data = *info; 366 init_cpu_features(&boot_cpu_data); 367 } 368 369 device_initcall(cpuinfo_regs_init); 370