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 sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(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_BOOT));
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
housekeeping_show(struct device * dev,struct device_attribute * attr,char * buf)303 static ssize_t housekeeping_show(struct device *dev,
304 struct device_attribute *attr, char *buf)
305 {
306 const struct cpumask *hk_mask;
307
308 hk_mask = housekeeping_cpumask(HK_TYPE_KERNEL_NOISE);
309
310 if (housekeeping_enabled(HK_TYPE_KERNEL_NOISE))
311 return sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(hk_mask));
312 return sysfs_emit(buf, "\n");
313 }
314 static DEVICE_ATTR_RO(housekeeping);
315
316 #ifdef CONFIG_NO_HZ_FULL
nohz_full_show(struct device * dev,struct device_attribute * attr,char * buf)317 static ssize_t nohz_full_show(struct device *dev,
318 struct device_attribute *attr,
319 char *buf)
320 {
321 if (cpumask_available(tick_nohz_full_mask))
322 return sysfs_emit(buf, "%*pbl\n",
323 cpumask_pr_args(tick_nohz_full_mask));
324 return sysfs_emit(buf, "\n");
325 }
326 static DEVICE_ATTR_RO(nohz_full);
327 #endif
328
329 #ifdef CONFIG_CRASH_HOTPLUG
crash_hotplug_show(struct device * dev,struct device_attribute * attr,char * buf)330 static ssize_t crash_hotplug_show(struct device *dev,
331 struct device_attribute *attr,
332 char *buf)
333 {
334 return sysfs_emit(buf, "%d\n", crash_check_hotplug_support());
335 }
336 static DEVICE_ATTR_RO(crash_hotplug);
337 #endif
338
cpu_device_release(struct device * dev)339 static void cpu_device_release(struct device *dev)
340 {
341 /*
342 * This is an empty function to prevent the driver core from spitting a
343 * warning at us. Yes, I know this is directly opposite of what the
344 * documentation for the driver core and kobjects say, and the author
345 * of this code has already been publicly ridiculed for doing
346 * something as foolish as this. However, at this point in time, it is
347 * the only way to handle the issue of statically allocated cpu
348 * devices. The different architectures will have their cpu device
349 * code reworked to properly handle this in the near future, so this
350 * function will then be changed to correctly free up the memory held
351 * by the cpu device.
352 *
353 * Never copy this way of doing things, or you too will be made fun of
354 * on the linux-kernel list, you have been warned.
355 */
356 }
357
358 #ifdef CONFIG_GENERIC_CPU_AUTOPROBE
print_cpu_modalias(struct device * dev,struct device_attribute * attr,char * buf)359 static ssize_t print_cpu_modalias(struct device *dev,
360 struct device_attribute *attr,
361 char *buf)
362 {
363 int len = 0;
364 u32 i;
365
366 len += sysfs_emit_at(buf, len,
367 "cpu:type:" CPU_FEATURE_TYPEFMT ":feature:",
368 CPU_FEATURE_TYPEVAL);
369
370 for (i = 0; i < MAX_CPU_FEATURES; i++)
371 if (cpu_have_feature(i)) {
372 if (len + sizeof(",XXXX\n") >= PAGE_SIZE) {
373 WARN(1, "CPU features overflow page\n");
374 break;
375 }
376 len += sysfs_emit_at(buf, len, ",%04X", i);
377 }
378 len += sysfs_emit_at(buf, len, "\n");
379 return len;
380 }
381
cpu_uevent(const struct device * dev,struct kobj_uevent_env * env)382 static int cpu_uevent(const struct device *dev, struct kobj_uevent_env *env)
383 {
384 char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
385 if (buf) {
386 print_cpu_modalias(NULL, NULL, buf);
387 add_uevent_var(env, "MODALIAS=%s", buf);
388 kfree(buf);
389 }
390 return 0;
391 }
392 #endif
393
394 #ifdef CONFIG_PREFERRED_CPU
preferred_show(struct device * dev,struct device_attribute * attr,char * buf)395 static ssize_t preferred_show(struct device *dev,
396 struct device_attribute *attr, char *buf)
397 {
398 return sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(cpu_preferred_mask));
399 }
400 static DEVICE_ATTR_RO(preferred);
401 #endif
402
403 const struct bus_type cpu_subsys = {
404 .name = "cpu",
405 .dev_name = "cpu",
406 .match = cpu_subsys_match,
407 #ifdef CONFIG_HOTPLUG_CPU
408 .online = cpu_subsys_online,
409 .offline = cpu_subsys_offline,
410 #endif
411 #ifdef CONFIG_GENERIC_CPU_AUTOPROBE
412 .uevent = cpu_uevent,
413 #endif
414 };
415 EXPORT_SYMBOL_GPL(cpu_subsys);
416
417 /*
418 * register_cpu - Setup a sysfs device for a CPU.
419 * @cpu - cpu->hotpluggable field set to 1 will generate a control file in
420 * sysfs for this CPU.
421 * @num - CPU number to use when creating the device.
422 *
423 * Initialize and register the CPU device.
424 */
register_cpu(struct cpu * cpu,int num)425 int register_cpu(struct cpu *cpu, int num)
426 {
427 int error;
428
429 cpu->node_id = cpu_to_node(num);
430 memset(&cpu->dev, 0x00, sizeof(struct device));
431 cpu->dev.id = num;
432 cpu->dev.bus = &cpu_subsys;
433 cpu->dev.release = cpu_device_release;
434 dev_assign_offline_disabled(&cpu->dev, !cpu->hotpluggable);
435 dev_assign_offline(&cpu->dev, !cpu_online(num));
436 cpu->dev.of_node = of_get_cpu_node(num, NULL);
437 cpu->dev.groups = common_cpu_attr_groups;
438 if (cpu->hotpluggable)
439 cpu->dev.groups = hotplugable_cpu_attr_groups;
440 error = device_register(&cpu->dev);
441 if (error) {
442 put_device(&cpu->dev);
443 return error;
444 }
445
446 per_cpu(cpu_sys_devices, num) = &cpu->dev;
447 register_cpu_under_node(num, cpu_to_node(num));
448 dev_pm_qos_expose_latency_limit(&cpu->dev,
449 PM_QOS_RESUME_LATENCY_NO_CONSTRAINT);
450 set_cpu_enabled(num, true);
451
452 return 0;
453 }
454
get_cpu_device(unsigned int cpu)455 struct device *get_cpu_device(unsigned int cpu)
456 {
457 if (cpu < nr_cpu_ids && cpu_possible(cpu))
458 return per_cpu(cpu_sys_devices, cpu);
459 else
460 return NULL;
461 }
462 EXPORT_SYMBOL_GPL(get_cpu_device);
463
device_create_release(struct device * dev)464 static void device_create_release(struct device *dev)
465 {
466 kfree(dev);
467 }
468
469 __printf(4, 0)
470 static struct device *
__cpu_device_create(struct device * parent,void * drvdata,const struct attribute_group ** groups,const char * fmt,va_list args)471 __cpu_device_create(struct device *parent, void *drvdata,
472 const struct attribute_group **groups,
473 const char *fmt, va_list args)
474 {
475 struct device *dev = NULL;
476 int retval = -ENOMEM;
477
478 dev = kzalloc_obj(*dev);
479 if (!dev)
480 goto error;
481
482 device_initialize(dev);
483 dev->parent = parent;
484 dev->groups = groups;
485 dev->release = device_create_release;
486 device_set_pm_not_required(dev);
487 dev_set_drvdata(dev, drvdata);
488
489 retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
490 if (retval)
491 goto error;
492
493 retval = device_add(dev);
494 if (retval)
495 goto error;
496
497 return dev;
498
499 error:
500 put_device(dev);
501 return ERR_PTR(retval);
502 }
503
cpu_device_create(struct device * parent,void * drvdata,const struct attribute_group ** groups,const char * fmt,...)504 struct device *cpu_device_create(struct device *parent, void *drvdata,
505 const struct attribute_group **groups,
506 const char *fmt, ...)
507 {
508 va_list vargs;
509 struct device *dev;
510
511 va_start(vargs, fmt);
512 dev = __cpu_device_create(parent, drvdata, groups, fmt, vargs);
513 va_end(vargs);
514 return dev;
515 }
516 EXPORT_SYMBOL_GPL(cpu_device_create);
517
518 #ifdef CONFIG_GENERIC_CPU_AUTOPROBE
519 static DEVICE_ATTR(modalias, 0444, print_cpu_modalias, NULL);
520 #endif
521
522 static struct attribute *cpu_root_attrs[] = {
523 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
524 &dev_attr_probe.attr,
525 &dev_attr_release.attr,
526 #endif
527 &cpu_attrs[0].attr.attr,
528 &cpu_attrs[1].attr.attr,
529 &cpu_attrs[2].attr.attr,
530 &dev_attr_kernel_max.attr,
531 &dev_attr_offline.attr,
532 &dev_attr_enabled.attr,
533 &dev_attr_isolated.attr,
534 &dev_attr_housekeeping.attr,
535 #ifdef CONFIG_NO_HZ_FULL
536 &dev_attr_nohz_full.attr,
537 #endif
538 #ifdef CONFIG_CRASH_HOTPLUG
539 &dev_attr_crash_hotplug.attr,
540 #endif
541 #ifdef CONFIG_GENERIC_CPU_AUTOPROBE
542 &dev_attr_modalias.attr,
543 #endif
544 #ifdef CONFIG_PREFERRED_CPU
545 &dev_attr_preferred.attr,
546 #endif
547 NULL
548 };
549
550 static const struct attribute_group cpu_root_attr_group = {
551 .attrs = cpu_root_attrs,
552 };
553
554 static const struct attribute_group *cpu_root_attr_groups[] = {
555 &cpu_root_attr_group,
556 NULL,
557 };
558
cpu_is_hotpluggable(unsigned int cpu)559 bool cpu_is_hotpluggable(unsigned int cpu)
560 {
561 struct device *dev = get_cpu_device(cpu);
562 return dev && container_of(dev, struct cpu, dev)->hotpluggable
563 && tick_nohz_cpu_hotpluggable(cpu);
564 }
565 EXPORT_SYMBOL_GPL(cpu_is_hotpluggable);
566
567 #ifdef CONFIG_GENERIC_CPU_DEVICES
568 DEFINE_PER_CPU(struct cpu, cpu_devices);
569
arch_cpu_is_hotpluggable(int cpu)570 bool __weak arch_cpu_is_hotpluggable(int cpu)
571 {
572 return false;
573 }
574
arch_register_cpu(int cpu)575 int __weak arch_register_cpu(int cpu)
576 {
577 struct cpu *c = &per_cpu(cpu_devices, cpu);
578
579 c->hotpluggable = arch_cpu_is_hotpluggable(cpu);
580
581 return register_cpu(c, cpu);
582 }
583
584 #ifdef CONFIG_HOTPLUG_CPU
arch_unregister_cpu(int num)585 void __weak arch_unregister_cpu(int num)
586 {
587 unregister_cpu(&per_cpu(cpu_devices, num));
588 }
589 #endif /* CONFIG_HOTPLUG_CPU */
590 #endif /* CONFIG_GENERIC_CPU_DEVICES */
591
cpu_dev_register_generic(void)592 static void __init cpu_dev_register_generic(void)
593 {
594 int i, ret;
595
596 if (!IS_ENABLED(CONFIG_GENERIC_CPU_DEVICES))
597 return;
598
599 for_each_present_cpu(i) {
600 ret = arch_register_cpu(i);
601 if (ret && ret != -EPROBE_DEFER)
602 pr_warn("register_cpu %d failed (%d)\n", i, ret);
603 }
604 }
605
606 #ifdef CONFIG_GENERIC_CPU_VULNERABILITIES
cpu_show_not_affected(struct device * dev,struct device_attribute * attr,char * buf)607 static ssize_t cpu_show_not_affected(struct device *dev,
608 struct device_attribute *attr, char *buf)
609 {
610 return sysfs_emit(buf, "Not affected\n");
611 }
612
613 #define CPU_SHOW_VULN_FALLBACK(func) \
614 ssize_t cpu_show_##func(struct device *, \
615 struct device_attribute *, char *) \
616 __attribute__((weak, alias("cpu_show_not_affected")))
617
618 CPU_SHOW_VULN_FALLBACK(meltdown);
619 CPU_SHOW_VULN_FALLBACK(spectre_v1);
620 CPU_SHOW_VULN_FALLBACK(spectre_v2);
621 CPU_SHOW_VULN_FALLBACK(spec_store_bypass);
622 CPU_SHOW_VULN_FALLBACK(l1tf);
623 CPU_SHOW_VULN_FALLBACK(mds);
624 CPU_SHOW_VULN_FALLBACK(tsx_async_abort);
625 CPU_SHOW_VULN_FALLBACK(itlb_multihit);
626 CPU_SHOW_VULN_FALLBACK(srbds);
627 CPU_SHOW_VULN_FALLBACK(mmio_stale_data);
628 CPU_SHOW_VULN_FALLBACK(retbleed);
629 CPU_SHOW_VULN_FALLBACK(spec_rstack_overflow);
630 CPU_SHOW_VULN_FALLBACK(gds);
631 CPU_SHOW_VULN_FALLBACK(reg_file_data_sampling);
632 CPU_SHOW_VULN_FALLBACK(ghostwrite);
633 CPU_SHOW_VULN_FALLBACK(old_microcode);
634 CPU_SHOW_VULN_FALLBACK(indirect_target_selection);
635 CPU_SHOW_VULN_FALLBACK(tsa);
636 CPU_SHOW_VULN_FALLBACK(vmscape);
637
638 static DEVICE_ATTR(meltdown, 0444, cpu_show_meltdown, NULL);
639 static DEVICE_ATTR(spectre_v1, 0444, cpu_show_spectre_v1, NULL);
640 static DEVICE_ATTR(spectre_v2, 0444, cpu_show_spectre_v2, NULL);
641 static DEVICE_ATTR(spec_store_bypass, 0444, cpu_show_spec_store_bypass, NULL);
642 static DEVICE_ATTR(l1tf, 0444, cpu_show_l1tf, NULL);
643 static DEVICE_ATTR(mds, 0444, cpu_show_mds, NULL);
644 static DEVICE_ATTR(tsx_async_abort, 0444, cpu_show_tsx_async_abort, NULL);
645 static DEVICE_ATTR(itlb_multihit, 0444, cpu_show_itlb_multihit, NULL);
646 static DEVICE_ATTR(srbds, 0444, cpu_show_srbds, NULL);
647 static DEVICE_ATTR(mmio_stale_data, 0444, cpu_show_mmio_stale_data, NULL);
648 static DEVICE_ATTR(retbleed, 0444, cpu_show_retbleed, NULL);
649 static DEVICE_ATTR(spec_rstack_overflow, 0444, cpu_show_spec_rstack_overflow, NULL);
650 static DEVICE_ATTR(gather_data_sampling, 0444, cpu_show_gds, NULL);
651 static DEVICE_ATTR(reg_file_data_sampling, 0444, cpu_show_reg_file_data_sampling, NULL);
652 static DEVICE_ATTR(ghostwrite, 0444, cpu_show_ghostwrite, NULL);
653 static DEVICE_ATTR(old_microcode, 0444, cpu_show_old_microcode, NULL);
654 static DEVICE_ATTR(indirect_target_selection, 0444, cpu_show_indirect_target_selection, NULL);
655 static DEVICE_ATTR(tsa, 0444, cpu_show_tsa, NULL);
656 static DEVICE_ATTR(vmscape, 0444, cpu_show_vmscape, NULL);
657
658 static struct attribute *cpu_root_vulnerabilities_attrs[] = {
659 &dev_attr_meltdown.attr,
660 &dev_attr_spectre_v1.attr,
661 &dev_attr_spectre_v2.attr,
662 &dev_attr_spec_store_bypass.attr,
663 &dev_attr_l1tf.attr,
664 &dev_attr_mds.attr,
665 &dev_attr_tsx_async_abort.attr,
666 &dev_attr_itlb_multihit.attr,
667 &dev_attr_srbds.attr,
668 &dev_attr_mmio_stale_data.attr,
669 &dev_attr_retbleed.attr,
670 &dev_attr_spec_rstack_overflow.attr,
671 &dev_attr_gather_data_sampling.attr,
672 &dev_attr_reg_file_data_sampling.attr,
673 &dev_attr_ghostwrite.attr,
674 &dev_attr_old_microcode.attr,
675 &dev_attr_indirect_target_selection.attr,
676 &dev_attr_tsa.attr,
677 &dev_attr_vmscape.attr,
678 NULL
679 };
680
681 static const struct attribute_group cpu_root_vulnerabilities_group = {
682 .name = "vulnerabilities",
683 .attrs = cpu_root_vulnerabilities_attrs,
684 };
685
cpu_register_vulnerabilities(void)686 static void __init cpu_register_vulnerabilities(void)
687 {
688 struct device *dev = bus_get_dev_root(&cpu_subsys);
689
690 if (dev) {
691 if (sysfs_create_group(&dev->kobj, &cpu_root_vulnerabilities_group))
692 pr_err("Unable to register CPU vulnerabilities\n");
693 put_device(dev);
694 }
695 }
696
697 #else
cpu_register_vulnerabilities(void)698 static inline void cpu_register_vulnerabilities(void) { }
699 #endif
700
cpu_dev_init(void)701 void __init cpu_dev_init(void)
702 {
703 if (subsys_system_register(&cpu_subsys, cpu_root_attr_groups))
704 panic("Failed to register CPU subsystem");
705
706 cpu_dev_register_generic();
707 cpu_register_vulnerabilities();
708 }
709