| 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * CPU subsystem support |
| 4 | */ |
| 5 | |
| 6 | #include <linux/kernel.h> |
| 7 | #include <linux/module.h> |
| 8 | #include <linux/init.h> |
| 9 | #include <linux/sched.h> |
| 10 | #include <linux/cpu.h> |
| 11 | #include <linux/topology.h> |
| 12 | #include <linux/device.h> |
| 13 | #include <linux/node.h> |
| 14 | #include <linux/gfp.h> |
| 15 | #include <linux/slab.h> |
| 16 | #include <linux/percpu.h> |
| 17 | #include <linux/acpi.h> |
| 18 | #include <linux/of.h> |
| 19 | #include <linux/cpufeature.h> |
| 20 | #include <linux/tick.h> |
| 21 | #include <linux/pm_qos.h> |
| 22 | #include <linux/delay.h> |
| 23 | #include <linux/sched/isolation.h> |
| 24 | |
| 25 | #include "base.h" |
| 26 | |
| 27 | static DEFINE_PER_CPU(struct device *, cpu_sys_devices); |
| 28 | |
| 29 | static int cpu_subsys_match(struct device *dev, struct device_driver *drv) |
| 30 | { |
| 31 | /* ACPI style match is the only one that may succeed. */ |
| 32 | if (acpi_driver_match_device(dev, drv)) |
| 33 | return 1; |
| 34 | |
| 35 | return 0; |
| 36 | } |
| 37 | |
| 38 | #ifdef CONFIG_HOTPLUG_CPU |
| 39 | static void change_cpu_under_node(struct cpu *cpu, |
| 40 | unsigned int from_nid, unsigned int to_nid) |
| 41 | { |
| 42 | int cpuid = cpu->dev.id; |
| 43 | unregister_cpu_under_node(cpuid, from_nid); |
| 44 | register_cpu_under_node(cpuid, to_nid); |
| 45 | cpu->node_id = to_nid; |
| 46 | } |
| 47 | |
| 48 | static int cpu_subsys_online(struct device *dev) |
| 49 | { |
| 50 | struct cpu *cpu = container_of(dev, struct cpu, dev); |
| 51 | int cpuid = dev->id; |
| 52 | int from_nid, to_nid; |
| 53 | int ret; |
| 54 | int retries = 0; |
| 55 | |
| 56 | from_nid = cpu_to_node(cpuid); |
| 57 | if (from_nid == NUMA_NO_NODE) |
| 58 | return -ENODEV; |
| 59 | |
| 60 | retry: |
| 61 | ret = cpu_device_up(dev); |
| 62 | |
| 63 | /* |
| 64 | * If -EBUSY is returned, it is likely that hotplug is temporarily |
| 65 | * disabled when cpu_hotplug_disable() was called. This condition is |
| 66 | * transient. So we retry after waiting for an exponentially |
| 67 | * increasing delay up to a total of at least 620ms as some PCI |
| 68 | * device initialization can take quite a while. |
| 69 | */ |
| 70 | if (ret == -EBUSY) { |
| 71 | retries++; |
| 72 | if (retries > 5) |
| 73 | return ret; |
| 74 | msleep(10 * (1 << retries)); |
| 75 | goto retry; |
| 76 | } |
| 77 | |
| 78 | /* |
| 79 | * When hot adding memory to memoryless node and enabling a cpu |
| 80 | * on the node, node number of the cpu may internally change. |
| 81 | */ |
| 82 | to_nid = cpu_to_node(cpuid); |
| 83 | if (from_nid != to_nid) |
| 84 | change_cpu_under_node(cpu, from_nid, to_nid); |
| 85 | |
| 86 | return ret; |
| 87 | } |
| 88 | |
| 89 | static int cpu_subsys_offline(struct device *dev) |
| 90 | { |
| 91 | return cpu_device_down(dev); |
| 92 | } |
| 93 | |
| 94 | void unregister_cpu(struct cpu *cpu) |
| 95 | { |
| 96 | int logical_cpu = cpu->dev.id; |
| 97 | |
| 98 | unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu)); |
| 99 | |
| 100 | device_unregister(&cpu->dev); |
| 101 | per_cpu(cpu_sys_devices, logical_cpu) = NULL; |
| 102 | return; |
| 103 | } |
| 104 | |
| 105 | #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE |
| 106 | static ssize_t cpu_probe_store(struct device *dev, |
| 107 | struct device_attribute *attr, |
| 108 | const char *buf, |
| 109 | size_t count) |
| 110 | { |
| 111 | ssize_t cnt; |
| 112 | int ret; |
| 113 | |
| 114 | ret = lock_device_hotplug_sysfs(); |
| 115 | if (ret) |
| 116 | return ret; |
| 117 | |
| 118 | cnt = arch_cpu_probe(buf, count); |
| 119 | |
| 120 | unlock_device_hotplug(); |
| 121 | return cnt; |
| 122 | } |
| 123 | |
| 124 | static ssize_t cpu_release_store(struct device *dev, |
| 125 | struct device_attribute *attr, |
| 126 | const char *buf, |
| 127 | size_t count) |
| 128 | { |
| 129 | ssize_t cnt; |
| 130 | int ret; |
| 131 | |
| 132 | ret = lock_device_hotplug_sysfs(); |
| 133 | if (ret) |
| 134 | return ret; |
| 135 | |
| 136 | cnt = arch_cpu_release(buf, count); |
| 137 | |
| 138 | unlock_device_hotplug(); |
| 139 | return cnt; |
| 140 | } |
| 141 | |
| 142 | static DEVICE_ATTR(probe, S_IWUSR, NULL, cpu_probe_store); |
| 143 | static DEVICE_ATTR(release, S_IWUSR, NULL, cpu_release_store); |
| 144 | #endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */ |
| 145 | #endif /* CONFIG_HOTPLUG_CPU */ |
| 146 | |
| 147 | #ifdef CONFIG_CRASH_DUMP |
| 148 | #include <linux/kexec.h> |
| 149 | |
| 150 | static ssize_t crash_notes_show(struct device *dev, |
| 151 | struct device_attribute *attr, |
| 152 | char *buf) |
| 153 | { |
| 154 | struct cpu *cpu = container_of(dev, struct cpu, dev); |
| 155 | unsigned long long addr; |
| 156 | int cpunum; |
| 157 | |
| 158 | cpunum = cpu->dev.id; |
| 159 | |
| 160 | /* |
| 161 | * Might be reading other cpu's data based on which cpu read thread |
| 162 | * has been scheduled. But cpu data (memory) is allocated once during |
| 163 | * boot up and this data does not change there after. Hence this |
| 164 | * operation should be safe. No locking required. |
| 165 | */ |
| 166 | addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpunum)); |
| 167 | |
| 168 | return sysfs_emit(buf, "%llx\n", addr); |
| 169 | } |
| 170 | static DEVICE_ATTR_ADMIN_RO(crash_notes); |
| 171 | |
| 172 | static ssize_t crash_notes_size_show(struct device *dev, |
| 173 | struct device_attribute *attr, |
| 174 | char *buf) |
| 175 | { |
| 176 | return sysfs_emit(buf, "%zu\n", sizeof(note_buf_t)); |
| 177 | } |
| 178 | static DEVICE_ATTR_ADMIN_RO(crash_notes_size); |
| 179 | |
| 180 | static struct attribute *crash_note_cpu_attrs[] = { |
| 181 | &dev_attr_crash_notes.attr, |
| 182 | &dev_attr_crash_notes_size.attr, |
| 183 | NULL |
| 184 | }; |
| 185 | |
| 186 | static const struct attribute_group crash_note_cpu_attr_group = { |
| 187 | .attrs = crash_note_cpu_attrs, |
| 188 | }; |
| 189 | #endif |
| 190 | |
| 191 | static const struct attribute_group *common_cpu_attr_groups[] = { |
| 192 | #ifdef CONFIG_CRASH_DUMP |
| 193 | &crash_note_cpu_attr_group, |
| 194 | #endif |
| 195 | NULL |
| 196 | }; |
| 197 | |
| 198 | static const struct attribute_group *hotplugable_cpu_attr_groups[] = { |
| 199 | #ifdef CONFIG_CRASH_DUMP |
| 200 | &crash_note_cpu_attr_group, |
| 201 | #endif |
| 202 | NULL |
| 203 | }; |
| 204 | |
| 205 | /* |
| 206 | * Print cpu online, possible, present, and system maps |
| 207 | */ |
| 208 | |
| 209 | struct cpu_attr { |
| 210 | struct device_attribute attr; |
| 211 | const struct cpumask *const map; |
| 212 | }; |
| 213 | |
| 214 | static ssize_t show_cpus_attr(struct device *dev, |
| 215 | struct device_attribute *attr, |
| 216 | char *buf) |
| 217 | { |
| 218 | struct cpu_attr *ca = container_of(attr, struct cpu_attr, attr); |
| 219 | |
| 220 | return cpumap_print_to_pagebuf(true, buf, ca->map); |
| 221 | } |
| 222 | |
| 223 | #define _CPU_ATTR(name, map) \ |
| 224 | { __ATTR(name, 0444, show_cpus_attr, NULL), map } |
| 225 | |
| 226 | /* Keep in sync with cpu_subsys_attrs */ |
| 227 | static struct cpu_attr cpu_attrs[] = { |
| 228 | _CPU_ATTR(online, &__cpu_online_mask), |
| 229 | _CPU_ATTR(possible, &__cpu_possible_mask), |
| 230 | _CPU_ATTR(present, &__cpu_present_mask), |
| 231 | }; |
| 232 | |
| 233 | /* |
| 234 | * Print values for NR_CPUS and offlined cpus |
| 235 | */ |
| 236 | static ssize_t print_cpus_kernel_max(struct device *dev, |
| 237 | struct device_attribute *attr, char *buf) |
| 238 | { |
| 239 | return sysfs_emit(buf, "%d\n", NR_CPUS - 1); |
| 240 | } |
| 241 | static DEVICE_ATTR(kernel_max, 0444, print_cpus_kernel_max, NULL); |
| 242 | |
| 243 | /* arch-optional setting to enable display of offline cpus >= nr_cpu_ids */ |
| 244 | unsigned int total_cpus; |
| 245 | |
| 246 | static ssize_t print_cpus_offline(struct device *dev, |
| 247 | struct device_attribute *attr, char *buf) |
| 248 | { |
| 249 | int len = 0; |
| 250 | cpumask_var_t offline; |
| 251 | |
| 252 | /* display offline cpus < nr_cpu_ids */ |
| 253 | if (!alloc_cpumask_var(&offline, GFP_KERNEL)) |
| 254 | return -ENOMEM; |
| 255 | cpumask_andnot(offline, cpu_possible_mask, cpu_online_mask); |
| 256 | len += sysfs_emit_at(buf, len, "%*pbl", cpumask_pr_args(offline)); |
| 257 | free_cpumask_var(offline); |
| 258 | |
| 259 | /* display offline cpus >= nr_cpu_ids */ |
| 260 | if (total_cpus && nr_cpu_ids < total_cpus) { |
| 261 | len += sysfs_emit_at(buf, len, ","); |
| 262 | |
| 263 | if (nr_cpu_ids == total_cpus-1) |
| 264 | len += sysfs_emit_at(buf, len, "%u", nr_cpu_ids); |
| 265 | else |
| 266 | len += sysfs_emit_at(buf, len, "%u-%d", |
| 267 | nr_cpu_ids, total_cpus - 1); |
| 268 | } |
| 269 | |
| 270 | len += sysfs_emit_at(buf, len, "\n"); |
| 271 | |
| 272 | return len; |
| 273 | } |
| 274 | static DEVICE_ATTR(offline, 0444, print_cpus_offline, NULL); |
| 275 | |
| 276 | static ssize_t print_cpus_isolated(struct device *dev, |
| 277 | struct device_attribute *attr, char *buf) |
| 278 | { |
| 279 | int len; |
| 280 | cpumask_var_t isolated; |
| 281 | |
| 282 | if (!alloc_cpumask_var(&isolated, GFP_KERNEL)) |
| 283 | return -ENOMEM; |
| 284 | |
| 285 | cpumask_andnot(isolated, cpu_possible_mask, |
| 286 | housekeeping_cpumask(HK_TYPE_DOMAIN)); |
| 287 | len = sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(isolated)); |
| 288 | |
| 289 | free_cpumask_var(isolated); |
| 290 | |
| 291 | return len; |
| 292 | } |
| 293 | static DEVICE_ATTR(isolated, 0444, print_cpus_isolated, NULL); |
| 294 | |
| 295 | #ifdef CONFIG_NO_HZ_FULL |
| 296 | static ssize_t print_cpus_nohz_full(struct device *dev, |
| 297 | struct device_attribute *attr, char *buf) |
| 298 | { |
| 299 | return sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(tick_nohz_full_mask)); |
| 300 | } |
| 301 | static DEVICE_ATTR(nohz_full, 0444, print_cpus_nohz_full, NULL); |
| 302 | #endif |
| 303 | |
| 304 | #ifdef CONFIG_CRASH_HOTPLUG |
| 305 | static ssize_t crash_hotplug_show(struct device *dev, |
| 306 | struct device_attribute *attr, |
| 307 | char *buf) |
| 308 | { |
| 309 | return sysfs_emit(buf, "%d\n", crash_check_hotplug_support()); |
| 310 | } |
| 311 | static DEVICE_ATTR_ADMIN_RO(crash_hotplug); |
| 312 | #endif |
| 313 | |
| 314 | static void cpu_device_release(struct device *dev) |
| 315 | { |
| 316 | /* |
| 317 | * This is an empty function to prevent the driver core from spitting a |
| 318 | * warning at us. Yes, I know this is directly opposite of what the |
| 319 | * documentation for the driver core and kobjects say, and the author |
| 320 | * of this code has already been publically ridiculed for doing |
| 321 | * something as foolish as this. However, at this point in time, it is |
| 322 | * the only way to handle the issue of statically allocated cpu |
| 323 | * devices. The different architectures will have their cpu device |
| 324 | * code reworked to properly handle this in the near future, so this |
| 325 | * function will then be changed to correctly free up the memory held |
| 326 | * by the cpu device. |
| 327 | * |
| 328 | * Never copy this way of doing things, or you too will be made fun of |
| 329 | * on the linux-kernel list, you have been warned. |
| 330 | */ |
| 331 | } |
| 332 | |
| 333 | #ifdef CONFIG_GENERIC_CPU_AUTOPROBE |
| 334 | static ssize_t print_cpu_modalias(struct device *dev, |
| 335 | struct device_attribute *attr, |
| 336 | char *buf) |
| 337 | { |
| 338 | int len = 0; |
| 339 | u32 i; |
| 340 | |
| 341 | len += sysfs_emit_at(buf, len, |
| 342 | "cpu:type:" CPU_FEATURE_TYPEFMT ":feature:", |
| 343 | CPU_FEATURE_TYPEVAL); |
| 344 | |
| 345 | for (i = 0; i < MAX_CPU_FEATURES; i++) |
| 346 | if (cpu_have_feature(i)) { |
| 347 | if (len + sizeof(",XXXX\n") >= PAGE_SIZE) { |
| 348 | WARN(1, "CPU features overflow page\n"); |
| 349 | break; |
| 350 | } |
| 351 | len += sysfs_emit_at(buf, len, ",%04X", i); |
| 352 | } |
| 353 | len += sysfs_emit_at(buf, len, "\n"); |
| 354 | return len; |
| 355 | } |
| 356 | |
| 357 | static int cpu_uevent(const struct device *dev, struct kobj_uevent_env *env) |
| 358 | { |
| 359 | char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL); |
| 360 | if (buf) { |
| 361 | print_cpu_modalias(NULL, NULL, buf); |
| 362 | add_uevent_var(env, "MODALIAS=%s", buf); |
| 363 | kfree(buf); |
| 364 | } |
| 365 | return 0; |
| 366 | } |
| 367 | #endif |
| 368 | |
| 369 | const struct bus_type cpu_subsys = { |
| 370 | .name = "cpu", |
| 371 | .dev_name = "cpu", |
| 372 | .match = cpu_subsys_match, |
| 373 | #ifdef CONFIG_HOTPLUG_CPU |
| 374 | .online = cpu_subsys_online, |
| 375 | .offline = cpu_subsys_offline, |
| 376 | #endif |
| 377 | #ifdef CONFIG_GENERIC_CPU_AUTOPROBE |
| 378 | .uevent = cpu_uevent, |
| 379 | #endif |
| 380 | }; |
| 381 | EXPORT_SYMBOL_GPL(cpu_subsys); |
| 382 | |
| 383 | /* |
| 384 | * register_cpu - Setup a sysfs device for a CPU. |
| 385 | * @cpu - cpu->hotpluggable field set to 1 will generate a control file in |
| 386 | * sysfs for this CPU. |
| 387 | * @num - CPU number to use when creating the device. |
| 388 | * |
| 389 | * Initialize and register the CPU device. |
| 390 | */ |
| 391 | int register_cpu(struct cpu *cpu, int num) |
| 392 | { |
| 393 | int error; |
| 394 | |
| 395 | cpu->node_id = cpu_to_node(num); |
| 396 | memset(&cpu->dev, 0x00, sizeof(struct device)); |
| 397 | cpu->dev.id = num; |
| 398 | cpu->dev.bus = &cpu_subsys; |
| 399 | cpu->dev.release = cpu_device_release; |
| 400 | cpu->dev.offline_disabled = !cpu->hotpluggable; |
| 401 | cpu->dev.offline = !cpu_online(num); |
| 402 | cpu->dev.of_node = of_get_cpu_node(num, NULL); |
| 403 | cpu->dev.groups = common_cpu_attr_groups; |
| 404 | if (cpu->hotpluggable) |
| 405 | cpu->dev.groups = hotplugable_cpu_attr_groups; |
| 406 | error = device_register(&cpu->dev); |
| 407 | if (error) { |
| 408 | put_device(&cpu->dev); |
| 409 | return error; |
| 410 | } |
| 411 | |
| 412 | per_cpu(cpu_sys_devices, num) = &cpu->dev; |
| 413 | register_cpu_under_node(num, cpu_to_node(num)); |
| 414 | dev_pm_qos_expose_latency_limit(&cpu->dev, |
| 415 | PM_QOS_RESUME_LATENCY_NO_CONSTRAINT); |
| 416 | |
| 417 | return 0; |
| 418 | } |
| 419 | |
| 420 | struct device *get_cpu_device(unsigned int cpu) |
| 421 | { |
| 422 | if (cpu < nr_cpu_ids && cpu_possible(cpu)) |
| 423 | return per_cpu(cpu_sys_devices, cpu); |
| 424 | else |
| 425 | return NULL; |
| 426 | } |
| 427 | EXPORT_SYMBOL_GPL(get_cpu_device); |
| 428 | |
| 429 | static void device_create_release(struct device *dev) |
| 430 | { |
| 431 | kfree(dev); |
| 432 | } |
| 433 | |
| 434 | __printf(4, 0) |
| 435 | static struct device * |
| 436 | __cpu_device_create(struct device *parent, void *drvdata, |
| 437 | const struct attribute_group **groups, |
| 438 | const char *fmt, va_list args) |
| 439 | { |
| 440 | struct device *dev = NULL; |
| 441 | int retval = -ENOMEM; |
| 442 | |
| 443 | dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
| 444 | if (!dev) |
| 445 | goto error; |
| 446 | |
| 447 | device_initialize(dev); |
| 448 | dev->parent = parent; |
| 449 | dev->groups = groups; |
| 450 | dev->release = device_create_release; |
| 451 | device_set_pm_not_required(dev); |
| 452 | dev_set_drvdata(dev, drvdata); |
| 453 | |
| 454 | retval = kobject_set_name_vargs(&dev->kobj, fmt, args); |
| 455 | if (retval) |
| 456 | goto error; |
| 457 | |
| 458 | retval = device_add(dev); |
| 459 | if (retval) |
| 460 | goto error; |
| 461 | |
| 462 | return dev; |
| 463 | |
| 464 | error: |
| 465 | put_device(dev); |
| 466 | return ERR_PTR(retval); |
| 467 | } |
| 468 | |
| 469 | struct device *cpu_device_create(struct device *parent, void *drvdata, |
| 470 | const struct attribute_group **groups, |
| 471 | const char *fmt, ...) |
| 472 | { |
| 473 | va_list vargs; |
| 474 | struct device *dev; |
| 475 | |
| 476 | va_start(vargs, fmt); |
| 477 | dev = __cpu_device_create(parent, drvdata, groups, fmt, vargs); |
| 478 | va_end(vargs); |
| 479 | return dev; |
| 480 | } |
| 481 | EXPORT_SYMBOL_GPL(cpu_device_create); |
| 482 | |
| 483 | #ifdef CONFIG_GENERIC_CPU_AUTOPROBE |
| 484 | static DEVICE_ATTR(modalias, 0444, print_cpu_modalias, NULL); |
| 485 | #endif |
| 486 | |
| 487 | static struct attribute *cpu_root_attrs[] = { |
| 488 | #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE |
| 489 | &dev_attr_probe.attr, |
| 490 | &dev_attr_release.attr, |
| 491 | #endif |
| 492 | &cpu_attrs[0].attr.attr, |
| 493 | &cpu_attrs[1].attr.attr, |
| 494 | &cpu_attrs[2].attr.attr, |
| 495 | &dev_attr_kernel_max.attr, |
| 496 | &dev_attr_offline.attr, |
| 497 | &dev_attr_isolated.attr, |
| 498 | #ifdef CONFIG_NO_HZ_FULL |
| 499 | &dev_attr_nohz_full.attr, |
| 500 | #endif |
| 501 | #ifdef CONFIG_CRASH_HOTPLUG |
| 502 | &dev_attr_crash_hotplug.attr, |
| 503 | #endif |
| 504 | #ifdef CONFIG_GENERIC_CPU_AUTOPROBE |
| 505 | &dev_attr_modalias.attr, |
| 506 | #endif |
| 507 | NULL |
| 508 | }; |
| 509 | |
| 510 | static const struct attribute_group cpu_root_attr_group = { |
| 511 | .attrs = cpu_root_attrs, |
| 512 | }; |
| 513 | |
| 514 | static const struct attribute_group *cpu_root_attr_groups[] = { |
| 515 | &cpu_root_attr_group, |
| 516 | NULL, |
| 517 | }; |
| 518 | |
| 519 | bool cpu_is_hotpluggable(unsigned int cpu) |
| 520 | { |
| 521 | struct device *dev = get_cpu_device(cpu); |
| 522 | return dev && container_of(dev, struct cpu, dev)->hotpluggable |
| 523 | && tick_nohz_cpu_hotpluggable(cpu); |
| 524 | } |
| 525 | EXPORT_SYMBOL_GPL(cpu_is_hotpluggable); |
| 526 | |
| 527 | #ifdef CONFIG_GENERIC_CPU_DEVICES |
| 528 | DEFINE_PER_CPU(struct cpu, cpu_devices); |
| 529 | |
| 530 | bool __weak arch_cpu_is_hotpluggable(int cpu) |
| 531 | { |
| 532 | return false; |
| 533 | } |
| 534 | |
| 535 | int __weak arch_register_cpu(int cpu) |
| 536 | { |
| 537 | struct cpu *c = &per_cpu(cpu_devices, cpu); |
| 538 | |
| 539 | c->hotpluggable = arch_cpu_is_hotpluggable(cpu); |
| 540 | |
| 541 | return register_cpu(c, cpu); |
| 542 | } |
| 543 | |
| 544 | #ifdef CONFIG_HOTPLUG_CPU |
| 545 | void __weak arch_unregister_cpu(int num) |
| 546 | { |
| 547 | unregister_cpu(&per_cpu(cpu_devices, num)); |
| 548 | } |
| 549 | #endif /* CONFIG_HOTPLUG_CPU */ |
| 550 | #endif /* CONFIG_GENERIC_CPU_DEVICES */ |
| 551 | |
| 552 | static void __init cpu_dev_register_generic(void) |
| 553 | { |
| 554 | int i, ret; |
| 555 | |
| 556 | if (!IS_ENABLED(CONFIG_GENERIC_CPU_DEVICES)) |
| 557 | return; |
| 558 | |
| 559 | for_each_present_cpu(i) { |
| 560 | ret = arch_register_cpu(i); |
| 561 | if (ret) |
| 562 | pr_warn("register_cpu %d failed (%d)\n", i, ret); |
| 563 | } |
| 564 | } |
| 565 | |
| 566 | #ifdef CONFIG_GENERIC_CPU_VULNERABILITIES |
| 567 | static ssize_t cpu_show_not_affected(struct device *dev, |
| 568 | struct device_attribute *attr, char *buf) |
| 569 | { |
| 570 | return sysfs_emit(buf, "Not affected\n"); |
| 571 | } |
| 572 | |
| 573 | #define CPU_SHOW_VULN_FALLBACK(func) \ |
| 574 | ssize_t cpu_show_##func(struct device *, \ |
| 575 | struct device_attribute *, char *) \ |
| 576 | __attribute__((weak, alias("cpu_show_not_affected"))) |
| 577 | |
| 578 | CPU_SHOW_VULN_FALLBACK(meltdown); |
| 579 | CPU_SHOW_VULN_FALLBACK(spectre_v1); |
| 580 | CPU_SHOW_VULN_FALLBACK(spectre_v2); |
| 581 | CPU_SHOW_VULN_FALLBACK(spec_store_bypass); |
| 582 | CPU_SHOW_VULN_FALLBACK(l1tf); |
| 583 | CPU_SHOW_VULN_FALLBACK(mds); |
| 584 | CPU_SHOW_VULN_FALLBACK(tsx_async_abort); |
| 585 | CPU_SHOW_VULN_FALLBACK(itlb_multihit); |
| 586 | CPU_SHOW_VULN_FALLBACK(srbds); |
| 587 | CPU_SHOW_VULN_FALLBACK(mmio_stale_data); |
| 588 | CPU_SHOW_VULN_FALLBACK(retbleed); |
| 589 | CPU_SHOW_VULN_FALLBACK(spec_rstack_overflow); |
| 590 | CPU_SHOW_VULN_FALLBACK(gds); |
| 591 | CPU_SHOW_VULN_FALLBACK(reg_file_data_sampling); |
| 592 | |
| 593 | static DEVICE_ATTR(meltdown, 0444, cpu_show_meltdown, NULL); |
| 594 | static DEVICE_ATTR(spectre_v1, 0444, cpu_show_spectre_v1, NULL); |
| 595 | static DEVICE_ATTR(spectre_v2, 0444, cpu_show_spectre_v2, NULL); |
| 596 | static DEVICE_ATTR(spec_store_bypass, 0444, cpu_show_spec_store_bypass, NULL); |
| 597 | static DEVICE_ATTR(l1tf, 0444, cpu_show_l1tf, NULL); |
| 598 | static DEVICE_ATTR(mds, 0444, cpu_show_mds, NULL); |
| 599 | static DEVICE_ATTR(tsx_async_abort, 0444, cpu_show_tsx_async_abort, NULL); |
| 600 | static DEVICE_ATTR(itlb_multihit, 0444, cpu_show_itlb_multihit, NULL); |
| 601 | static DEVICE_ATTR(srbds, 0444, cpu_show_srbds, NULL); |
| 602 | static DEVICE_ATTR(mmio_stale_data, 0444, cpu_show_mmio_stale_data, NULL); |
| 603 | static DEVICE_ATTR(retbleed, 0444, cpu_show_retbleed, NULL); |
| 604 | static DEVICE_ATTR(spec_rstack_overflow, 0444, cpu_show_spec_rstack_overflow, NULL); |
| 605 | static DEVICE_ATTR(gather_data_sampling, 0444, cpu_show_gds, NULL); |
| 606 | static DEVICE_ATTR(reg_file_data_sampling, 0444, cpu_show_reg_file_data_sampling, NULL); |
| 607 | |
| 608 | static struct attribute *cpu_root_vulnerabilities_attrs[] = { |
| 609 | &dev_attr_meltdown.attr, |
| 610 | &dev_attr_spectre_v1.attr, |
| 611 | &dev_attr_spectre_v2.attr, |
| 612 | &dev_attr_spec_store_bypass.attr, |
| 613 | &dev_attr_l1tf.attr, |
| 614 | &dev_attr_mds.attr, |
| 615 | &dev_attr_tsx_async_abort.attr, |
| 616 | &dev_attr_itlb_multihit.attr, |
| 617 | &dev_attr_srbds.attr, |
| 618 | &dev_attr_mmio_stale_data.attr, |
| 619 | &dev_attr_retbleed.attr, |
| 620 | &dev_attr_spec_rstack_overflow.attr, |
| 621 | &dev_attr_gather_data_sampling.attr, |
| 622 | &dev_attr_reg_file_data_sampling.attr, |
| 623 | NULL |
| 624 | }; |
| 625 | |
| 626 | static const struct attribute_group cpu_root_vulnerabilities_group = { |
| 627 | .name = "vulnerabilities", |
| 628 | .attrs = cpu_root_vulnerabilities_attrs, |
| 629 | }; |
| 630 | |
| 631 | static void __init cpu_register_vulnerabilities(void) |
| 632 | { |
| 633 | struct device *dev = bus_get_dev_root(&cpu_subsys); |
| 634 | |
| 635 | if (dev) { |
| 636 | if (sysfs_create_group(&dev->kobj, &cpu_root_vulnerabilities_group)) |
| 637 | pr_err("Unable to register CPU vulnerabilities\n"); |
| 638 | put_device(dev); |
| 639 | } |
| 640 | } |
| 641 | |
| 642 | #else |
| 643 | static inline void cpu_register_vulnerabilities(void) { } |
| 644 | #endif |
| 645 | |
| 646 | void __init cpu_dev_init(void) |
| 647 | { |
| 648 | if (subsys_system_register(&cpu_subsys, cpu_root_attr_groups)) |
| 649 | panic("Failed to register CPU subsystem"); |
| 650 | |
| 651 | cpu_dev_register_generic(); |
| 652 | cpu_register_vulnerabilities(); |
| 653 | } |