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
cpu_subsys_match(struct device * dev,const struct device_driver * drv)29 static int cpu_subsys_match(struct device *dev, const 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
change_cpu_under_node(struct cpu * cpu,unsigned int from_nid,unsigned int to_nid)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
cpu_subsys_online(struct device * dev)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
cpu_subsys_offline(struct device * dev)89 static int cpu_subsys_offline(struct device *dev)
90 {
91 return cpu_device_down(dev);
92 }
93
unregister_cpu(struct cpu * cpu)94 void unregister_cpu(struct cpu *cpu)
95 {
96 int logical_cpu = cpu->dev.id;
97
98 set_cpu_enabled(logical_cpu, false);
99 unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu));
100
101 device_unregister(&cpu->dev);
102 per_cpu(cpu_sys_devices, logical_cpu) = NULL;
103 return;
104 }
105
106 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
cpu_probe_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)107 static ssize_t cpu_probe_store(struct device *dev,
108 struct device_attribute *attr,
109 const char *buf,
110 size_t count)
111 {
112 ssize_t cnt;
113 int ret;
114
115 ret = lock_device_hotplug_sysfs();
116 if (ret)
117 return ret;
118
119 cnt = arch_cpu_probe(buf, count);
120
121 unlock_device_hotplug();
122 return cnt;
123 }
124
cpu_release_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)125 static ssize_t cpu_release_store(struct device *dev,
126 struct device_attribute *attr,
127 const char *buf,
128 size_t count)
129 {
130 ssize_t cnt;
131 int ret;
132
133 ret = lock_device_hotplug_sysfs();
134 if (ret)
135 return ret;
136
137 cnt = arch_cpu_release(buf, count);
138
139 unlock_device_hotplug();
140 return cnt;
141 }
142
143 static DEVICE_ATTR(probe, S_IWUSR, NULL, cpu_probe_store);
144 static DEVICE_ATTR(release, S_IWUSR, NULL, cpu_release_store);
145 #endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
146 #endif /* CONFIG_HOTPLUG_CPU */
147
148 #ifdef CONFIG_CRASH_DUMP
149 #include <linux/kexec.h>
150
crash_notes_show(struct device * dev,struct device_attribute * attr,char * buf)151 static ssize_t crash_notes_show(struct device *dev,
152 struct device_attribute *attr,
153 char *buf)
154 {
155 struct cpu *cpu = container_of(dev, struct cpu, dev);
156 unsigned long long addr;
157 int cpunum;
158
159 cpunum = cpu->dev.id;
160
161 /*
162 * Might be reading other cpu's data based on which cpu read thread
163 * has been scheduled. But cpu data (memory) is allocated once during
164 * boot up and this data does not change there after. Hence this
165 * operation should be safe. No locking required.
166 */
167 addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpunum));
168
169 return sysfs_emit(buf, "%llx\n", addr);
170 }
171 static DEVICE_ATTR_ADMIN_RO(crash_notes);
172
crash_notes_size_show(struct device * dev,struct device_attribute * attr,char * buf)173 static ssize_t crash_notes_size_show(struct device *dev,
174 struct device_attribute *attr,
175 char *buf)
176 {
177 return sysfs_emit(buf, "%zu\n", sizeof(note_buf_t));
178 }
179 static DEVICE_ATTR_ADMIN_RO(crash_notes_size);
180
181 static struct attribute *crash_note_cpu_attrs[] = {
182 &dev_attr_crash_notes.attr,
183 &dev_attr_crash_notes_size.attr,
184 NULL
185 };
186
187 static const struct attribute_group crash_note_cpu_attr_group = {
188 .attrs = crash_note_cpu_attrs,
189 };
190 #endif
191
192 static const struct attribute_group *common_cpu_attr_groups[] = {
193 #ifdef CONFIG_CRASH_DUMP
194 &crash_note_cpu_attr_group,
195 #endif
196 NULL
197 };
198
199 static const struct attribute_group *hotplugable_cpu_attr_groups[] = {
200 #ifdef CONFIG_CRASH_DUMP
201 &crash_note_cpu_attr_group,
202 #endif
203 NULL
204 };
205
206 /*
207 * Print cpu online, possible, present, and system maps
208 */
209
210 struct cpu_attr {
211 struct device_attribute attr;
212 const struct cpumask *const map;
213 };
214
show_cpus_attr(struct device * dev,struct device_attribute * attr,char * buf)215 static ssize_t show_cpus_attr(struct device *dev,
216 struct device_attribute *attr,
217 char *buf)
218 {
219 struct cpu_attr *ca = container_of(attr, struct cpu_attr, attr);
220
221 return cpumap_print_to_pagebuf(true, buf, ca->map);
222 }
223
224 #define _CPU_ATTR(name, map) \
225 { __ATTR(name, 0444, show_cpus_attr, NULL), map }
226
227 /* Keep in sync with cpu_subsys_attrs */
228 static struct cpu_attr cpu_attrs[] = {
229 _CPU_ATTR(online, &__cpu_online_mask),
230 _CPU_ATTR(possible, &__cpu_possible_mask),
231 _CPU_ATTR(present, &__cpu_present_mask),
232 };
233
234 /*
235 * Print values for NR_CPUS and offlined cpus
236 */
print_cpus_kernel_max(struct device * dev,struct device_attribute * attr,char * buf)237 static ssize_t print_cpus_kernel_max(struct device *dev,
238 struct device_attribute *attr, char *buf)
239 {
240 return sysfs_emit(buf, "%d\n", NR_CPUS - 1);
241 }
242 static DEVICE_ATTR(kernel_max, 0444, print_cpus_kernel_max, NULL);
243
244 /* arch-optional setting to enable display of offline cpus >= nr_cpu_ids */
245 unsigned int total_cpus;
246
print_cpus_offline(struct device * dev,struct device_attribute * attr,char * buf)247 static ssize_t print_cpus_offline(struct device *dev,
248 struct device_attribute *attr, char *buf)
249 {
250 int len = 0;
251 cpumask_var_t offline;
252
253 /* display offline cpus < nr_cpu_ids */
254 if (!alloc_cpumask_var(&offline, GFP_KERNEL))
255 return -ENOMEM;
256 cpumask_andnot(offline, cpu_possible_mask, cpu_online_mask);
257 len += sysfs_emit_at(buf, len, "%*pbl", cpumask_pr_args(offline));
258 free_cpumask_var(offline);
259
260 /* display offline cpus >= nr_cpu_ids */
261 if (total_cpus && nr_cpu_ids < total_cpus) {
262 len += sysfs_emit_at(buf, len, ",");
263
264 if (nr_cpu_ids == total_cpus-1)
265 len += sysfs_emit_at(buf, len, "%u", nr_cpu_ids);
266 else
267 len += sysfs_emit_at(buf, len, "%u-%d",
268 nr_cpu_ids, total_cpus - 1);
269 }
270
271 len += sysfs_emit_at(buf, len, "\n");
272
273 return len;
274 }
275 static DEVICE_ATTR(offline, 0444, print_cpus_offline, NULL);
276
print_cpus_enabled(struct device * dev,struct device_attribute * attr,char * buf)277 static ssize_t print_cpus_enabled(struct device *dev,
278 struct device_attribute *attr, char *buf)
279 {
280 return sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(cpu_enabled_mask));
281 }
282 static DEVICE_ATTR(enabled, 0444, print_cpus_enabled, NULL);
283
print_cpus_isolated(struct device * dev,struct device_attribute * attr,char * buf)284 static ssize_t print_cpus_isolated(struct device *dev,
285 struct device_attribute *attr, char *buf)
286 {
287 int len;
288 cpumask_var_t isolated;
289
290 if (!alloc_cpumask_var(&isolated, GFP_KERNEL))
291 return -ENOMEM;
292
293 cpumask_andnot(isolated, cpu_possible_mask,
294 housekeeping_cpumask(HK_TYPE_DOMAIN));
295 len = sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(isolated));
296
297 free_cpumask_var(isolated);
298
299 return len;
300 }
301 static DEVICE_ATTR(isolated, 0444, print_cpus_isolated, NULL);
302
303 #ifdef CONFIG_NO_HZ_FULL
print_cpus_nohz_full(struct device * dev,struct device_attribute * attr,char * buf)304 static ssize_t print_cpus_nohz_full(struct device *dev,
305 struct device_attribute *attr, char *buf)
306 {
307 return sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(tick_nohz_full_mask));
308 }
309 static DEVICE_ATTR(nohz_full, 0444, print_cpus_nohz_full, NULL);
310 #endif
311
312 #ifdef CONFIG_CRASH_HOTPLUG
crash_hotplug_show(struct device * dev,struct device_attribute * attr,char * buf)313 static ssize_t crash_hotplug_show(struct device *dev,
314 struct device_attribute *attr,
315 char *buf)
316 {
317 return sysfs_emit(buf, "%d\n", crash_check_hotplug_support());
318 }
319 static DEVICE_ATTR_RO(crash_hotplug);
320 #endif
321
cpu_device_release(struct device * dev)322 static void cpu_device_release(struct device *dev)
323 {
324 /*
325 * This is an empty function to prevent the driver core from spitting a
326 * warning at us. Yes, I know this is directly opposite of what the
327 * documentation for the driver core and kobjects say, and the author
328 * of this code has already been publically ridiculed for doing
329 * something as foolish as this. However, at this point in time, it is
330 * the only way to handle the issue of statically allocated cpu
331 * devices. The different architectures will have their cpu device
332 * code reworked to properly handle this in the near future, so this
333 * function will then be changed to correctly free up the memory held
334 * by the cpu device.
335 *
336 * Never copy this way of doing things, or you too will be made fun of
337 * on the linux-kernel list, you have been warned.
338 */
339 }
340
341 #ifdef CONFIG_GENERIC_CPU_AUTOPROBE
print_cpu_modalias(struct device * dev,struct device_attribute * attr,char * buf)342 static ssize_t print_cpu_modalias(struct device *dev,
343 struct device_attribute *attr,
344 char *buf)
345 {
346 int len = 0;
347 u32 i;
348
349 len += sysfs_emit_at(buf, len,
350 "cpu:type:" CPU_FEATURE_TYPEFMT ":feature:",
351 CPU_FEATURE_TYPEVAL);
352
353 for (i = 0; i < MAX_CPU_FEATURES; i++)
354 if (cpu_have_feature(i)) {
355 if (len + sizeof(",XXXX\n") >= PAGE_SIZE) {
356 WARN(1, "CPU features overflow page\n");
357 break;
358 }
359 len += sysfs_emit_at(buf, len, ",%04X", i);
360 }
361 len += sysfs_emit_at(buf, len, "\n");
362 return len;
363 }
364
cpu_uevent(const struct device * dev,struct kobj_uevent_env * env)365 static int cpu_uevent(const struct device *dev, struct kobj_uevent_env *env)
366 {
367 char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
368 if (buf) {
369 print_cpu_modalias(NULL, NULL, buf);
370 add_uevent_var(env, "MODALIAS=%s", buf);
371 kfree(buf);
372 }
373 return 0;
374 }
375 #endif
376
377 const struct bus_type cpu_subsys = {
378 .name = "cpu",
379 .dev_name = "cpu",
380 .match = cpu_subsys_match,
381 #ifdef CONFIG_HOTPLUG_CPU
382 .online = cpu_subsys_online,
383 .offline = cpu_subsys_offline,
384 #endif
385 #ifdef CONFIG_GENERIC_CPU_AUTOPROBE
386 .uevent = cpu_uevent,
387 #endif
388 };
389 EXPORT_SYMBOL_GPL(cpu_subsys);
390
391 /*
392 * register_cpu - Setup a sysfs device for a CPU.
393 * @cpu - cpu->hotpluggable field set to 1 will generate a control file in
394 * sysfs for this CPU.
395 * @num - CPU number to use when creating the device.
396 *
397 * Initialize and register the CPU device.
398 */
register_cpu(struct cpu * cpu,int num)399 int register_cpu(struct cpu *cpu, int num)
400 {
401 int error;
402
403 cpu->node_id = cpu_to_node(num);
404 memset(&cpu->dev, 0x00, sizeof(struct device));
405 cpu->dev.id = num;
406 cpu->dev.bus = &cpu_subsys;
407 cpu->dev.release = cpu_device_release;
408 cpu->dev.offline_disabled = !cpu->hotpluggable;
409 cpu->dev.offline = !cpu_online(num);
410 cpu->dev.of_node = of_get_cpu_node(num, NULL);
411 cpu->dev.groups = common_cpu_attr_groups;
412 if (cpu->hotpluggable)
413 cpu->dev.groups = hotplugable_cpu_attr_groups;
414 error = device_register(&cpu->dev);
415 if (error) {
416 put_device(&cpu->dev);
417 return error;
418 }
419
420 per_cpu(cpu_sys_devices, num) = &cpu->dev;
421 register_cpu_under_node(num, cpu_to_node(num));
422 dev_pm_qos_expose_latency_limit(&cpu->dev,
423 PM_QOS_RESUME_LATENCY_NO_CONSTRAINT);
424 set_cpu_enabled(num, true);
425
426 return 0;
427 }
428
get_cpu_device(unsigned int cpu)429 struct device *get_cpu_device(unsigned int cpu)
430 {
431 if (cpu < nr_cpu_ids && cpu_possible(cpu))
432 return per_cpu(cpu_sys_devices, cpu);
433 else
434 return NULL;
435 }
436 EXPORT_SYMBOL_GPL(get_cpu_device);
437
device_create_release(struct device * dev)438 static void device_create_release(struct device *dev)
439 {
440 kfree(dev);
441 }
442
443 __printf(4, 0)
444 static struct device *
__cpu_device_create(struct device * parent,void * drvdata,const struct attribute_group ** groups,const char * fmt,va_list args)445 __cpu_device_create(struct device *parent, void *drvdata,
446 const struct attribute_group **groups,
447 const char *fmt, va_list args)
448 {
449 struct device *dev = NULL;
450 int retval = -ENOMEM;
451
452 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
453 if (!dev)
454 goto error;
455
456 device_initialize(dev);
457 dev->parent = parent;
458 dev->groups = groups;
459 dev->release = device_create_release;
460 device_set_pm_not_required(dev);
461 dev_set_drvdata(dev, drvdata);
462
463 retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
464 if (retval)
465 goto error;
466
467 retval = device_add(dev);
468 if (retval)
469 goto error;
470
471 return dev;
472
473 error:
474 put_device(dev);
475 return ERR_PTR(retval);
476 }
477
cpu_device_create(struct device * parent,void * drvdata,const struct attribute_group ** groups,const char * fmt,...)478 struct device *cpu_device_create(struct device *parent, void *drvdata,
479 const struct attribute_group **groups,
480 const char *fmt, ...)
481 {
482 va_list vargs;
483 struct device *dev;
484
485 va_start(vargs, fmt);
486 dev = __cpu_device_create(parent, drvdata, groups, fmt, vargs);
487 va_end(vargs);
488 return dev;
489 }
490 EXPORT_SYMBOL_GPL(cpu_device_create);
491
492 #ifdef CONFIG_GENERIC_CPU_AUTOPROBE
493 static DEVICE_ATTR(modalias, 0444, print_cpu_modalias, NULL);
494 #endif
495
496 static struct attribute *cpu_root_attrs[] = {
497 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
498 &dev_attr_probe.attr,
499 &dev_attr_release.attr,
500 #endif
501 &cpu_attrs[0].attr.attr,
502 &cpu_attrs[1].attr.attr,
503 &cpu_attrs[2].attr.attr,
504 &dev_attr_kernel_max.attr,
505 &dev_attr_offline.attr,
506 &dev_attr_enabled.attr,
507 &dev_attr_isolated.attr,
508 #ifdef CONFIG_NO_HZ_FULL
509 &dev_attr_nohz_full.attr,
510 #endif
511 #ifdef CONFIG_CRASH_HOTPLUG
512 &dev_attr_crash_hotplug.attr,
513 #endif
514 #ifdef CONFIG_GENERIC_CPU_AUTOPROBE
515 &dev_attr_modalias.attr,
516 #endif
517 NULL
518 };
519
520 static const struct attribute_group cpu_root_attr_group = {
521 .attrs = cpu_root_attrs,
522 };
523
524 static const struct attribute_group *cpu_root_attr_groups[] = {
525 &cpu_root_attr_group,
526 NULL,
527 };
528
cpu_is_hotpluggable(unsigned int cpu)529 bool cpu_is_hotpluggable(unsigned int cpu)
530 {
531 struct device *dev = get_cpu_device(cpu);
532 return dev && container_of(dev, struct cpu, dev)->hotpluggable
533 && tick_nohz_cpu_hotpluggable(cpu);
534 }
535 EXPORT_SYMBOL_GPL(cpu_is_hotpluggable);
536
537 #ifdef CONFIG_GENERIC_CPU_DEVICES
538 DEFINE_PER_CPU(struct cpu, cpu_devices);
539
arch_cpu_is_hotpluggable(int cpu)540 bool __weak arch_cpu_is_hotpluggable(int cpu)
541 {
542 return false;
543 }
544
arch_register_cpu(int cpu)545 int __weak arch_register_cpu(int cpu)
546 {
547 struct cpu *c = &per_cpu(cpu_devices, cpu);
548
549 c->hotpluggable = arch_cpu_is_hotpluggable(cpu);
550
551 return register_cpu(c, cpu);
552 }
553
554 #ifdef CONFIG_HOTPLUG_CPU
arch_unregister_cpu(int num)555 void __weak arch_unregister_cpu(int num)
556 {
557 unregister_cpu(&per_cpu(cpu_devices, num));
558 }
559 #endif /* CONFIG_HOTPLUG_CPU */
560 #endif /* CONFIG_GENERIC_CPU_DEVICES */
561
cpu_dev_register_generic(void)562 static void __init cpu_dev_register_generic(void)
563 {
564 int i, ret;
565
566 if (!IS_ENABLED(CONFIG_GENERIC_CPU_DEVICES))
567 return;
568
569 for_each_present_cpu(i) {
570 ret = arch_register_cpu(i);
571 if (ret && ret != -EPROBE_DEFER)
572 pr_warn("register_cpu %d failed (%d)\n", i, ret);
573 }
574 }
575
576 #ifdef CONFIG_GENERIC_CPU_VULNERABILITIES
cpu_show_not_affected(struct device * dev,struct device_attribute * attr,char * buf)577 static ssize_t cpu_show_not_affected(struct device *dev,
578 struct device_attribute *attr, char *buf)
579 {
580 return sysfs_emit(buf, "Not affected\n");
581 }
582
583 #define CPU_SHOW_VULN_FALLBACK(func) \
584 ssize_t cpu_show_##func(struct device *, \
585 struct device_attribute *, char *) \
586 __attribute__((weak, alias("cpu_show_not_affected")))
587
588 CPU_SHOW_VULN_FALLBACK(meltdown);
589 CPU_SHOW_VULN_FALLBACK(spectre_v1);
590 CPU_SHOW_VULN_FALLBACK(spectre_v2);
591 CPU_SHOW_VULN_FALLBACK(spec_store_bypass);
592 CPU_SHOW_VULN_FALLBACK(l1tf);
593 CPU_SHOW_VULN_FALLBACK(mds);
594 CPU_SHOW_VULN_FALLBACK(tsx_async_abort);
595 CPU_SHOW_VULN_FALLBACK(itlb_multihit);
596 CPU_SHOW_VULN_FALLBACK(srbds);
597 CPU_SHOW_VULN_FALLBACK(mmio_stale_data);
598 CPU_SHOW_VULN_FALLBACK(retbleed);
599 CPU_SHOW_VULN_FALLBACK(spec_rstack_overflow);
600 CPU_SHOW_VULN_FALLBACK(gds);
601 CPU_SHOW_VULN_FALLBACK(reg_file_data_sampling);
602
603 static DEVICE_ATTR(meltdown, 0444, cpu_show_meltdown, NULL);
604 static DEVICE_ATTR(spectre_v1, 0444, cpu_show_spectre_v1, NULL);
605 static DEVICE_ATTR(spectre_v2, 0444, cpu_show_spectre_v2, NULL);
606 static DEVICE_ATTR(spec_store_bypass, 0444, cpu_show_spec_store_bypass, NULL);
607 static DEVICE_ATTR(l1tf, 0444, cpu_show_l1tf, NULL);
608 static DEVICE_ATTR(mds, 0444, cpu_show_mds, NULL);
609 static DEVICE_ATTR(tsx_async_abort, 0444, cpu_show_tsx_async_abort, NULL);
610 static DEVICE_ATTR(itlb_multihit, 0444, cpu_show_itlb_multihit, NULL);
611 static DEVICE_ATTR(srbds, 0444, cpu_show_srbds, NULL);
612 static DEVICE_ATTR(mmio_stale_data, 0444, cpu_show_mmio_stale_data, NULL);
613 static DEVICE_ATTR(retbleed, 0444, cpu_show_retbleed, NULL);
614 static DEVICE_ATTR(spec_rstack_overflow, 0444, cpu_show_spec_rstack_overflow, NULL);
615 static DEVICE_ATTR(gather_data_sampling, 0444, cpu_show_gds, NULL);
616 static DEVICE_ATTR(reg_file_data_sampling, 0444, cpu_show_reg_file_data_sampling, NULL);
617
618 static struct attribute *cpu_root_vulnerabilities_attrs[] = {
619 &dev_attr_meltdown.attr,
620 &dev_attr_spectre_v1.attr,
621 &dev_attr_spectre_v2.attr,
622 &dev_attr_spec_store_bypass.attr,
623 &dev_attr_l1tf.attr,
624 &dev_attr_mds.attr,
625 &dev_attr_tsx_async_abort.attr,
626 &dev_attr_itlb_multihit.attr,
627 &dev_attr_srbds.attr,
628 &dev_attr_mmio_stale_data.attr,
629 &dev_attr_retbleed.attr,
630 &dev_attr_spec_rstack_overflow.attr,
631 &dev_attr_gather_data_sampling.attr,
632 &dev_attr_reg_file_data_sampling.attr,
633 NULL
634 };
635
636 static const struct attribute_group cpu_root_vulnerabilities_group = {
637 .name = "vulnerabilities",
638 .attrs = cpu_root_vulnerabilities_attrs,
639 };
640
cpu_register_vulnerabilities(void)641 static void __init cpu_register_vulnerabilities(void)
642 {
643 struct device *dev = bus_get_dev_root(&cpu_subsys);
644
645 if (dev) {
646 if (sysfs_create_group(&dev->kobj, &cpu_root_vulnerabilities_group))
647 pr_err("Unable to register CPU vulnerabilities\n");
648 put_device(dev);
649 }
650 }
651
652 #else
cpu_register_vulnerabilities(void)653 static inline void cpu_register_vulnerabilities(void) { }
654 #endif
655
cpu_dev_init(void)656 void __init cpu_dev_init(void)
657 {
658 if (subsys_system_register(&cpu_subsys, cpu_root_attr_groups))
659 panic("Failed to register CPU subsystem");
660
661 cpu_dev_register_generic();
662 cpu_register_vulnerabilities();
663 }
664