1 | // SPDX-License-Identifier: GPL-2.0 |
2 | // Copyright (C) 2017 Arm Ltd. |
3 | #define pr_fmt(fmt) "sdei: " fmt |
4 | |
5 | #include <acpi/ghes.h> |
6 | #include <linux/acpi.h> |
7 | #include <linux/arm_sdei.h> |
8 | #include <linux/arm-smccc.h> |
9 | #include <linux/atomic.h> |
10 | #include <linux/bitops.h> |
11 | #include <linux/compiler.h> |
12 | #include <linux/cpuhotplug.h> |
13 | #include <linux/cpu.h> |
14 | #include <linux/cpu_pm.h> |
15 | #include <linux/errno.h> |
16 | #include <linux/hardirq.h> |
17 | #include <linux/kernel.h> |
18 | #include <linux/kprobes.h> |
19 | #include <linux/kvm_host.h> |
20 | #include <linux/list.h> |
21 | #include <linux/mutex.h> |
22 | #include <linux/notifier.h> |
23 | #include <linux/of.h> |
24 | #include <linux/of_platform.h> |
25 | #include <linux/percpu.h> |
26 | #include <linux/platform_device.h> |
27 | #include <linux/pm.h> |
28 | #include <linux/ptrace.h> |
29 | #include <linux/preempt.h> |
30 | #include <linux/reboot.h> |
31 | #include <linux/slab.h> |
32 | #include <linux/smp.h> |
33 | #include <linux/spinlock.h> |
34 | |
35 | /* |
36 | * The call to use to reach the firmware. |
37 | */ |
38 | static asmlinkage void (*sdei_firmware_call)(unsigned long function_id, |
39 | unsigned long arg0, unsigned long arg1, |
40 | unsigned long arg2, unsigned long arg3, |
41 | unsigned long arg4, struct arm_smccc_res *res); |
42 | |
43 | /* entry point from firmware to arch asm code */ |
44 | static unsigned long sdei_entry_point; |
45 | |
46 | static int sdei_hp_state; |
47 | |
48 | struct sdei_event { |
49 | /* These three are protected by the sdei_list_lock */ |
50 | struct list_head list; |
51 | bool reregister; |
52 | bool reenable; |
53 | |
54 | u32 event_num; |
55 | u8 type; |
56 | u8 priority; |
57 | |
58 | /* This pointer is handed to firmware as the event argument. */ |
59 | union { |
60 | /* Shared events */ |
61 | struct sdei_registered_event *registered; |
62 | |
63 | /* CPU private events */ |
64 | struct sdei_registered_event __percpu *private_registered; |
65 | }; |
66 | }; |
67 | |
68 | /* Take the mutex for any API call or modification. Take the mutex first. */ |
69 | static DEFINE_MUTEX(sdei_events_lock); |
70 | |
71 | /* and then hold this when modifying the list */ |
72 | static DEFINE_SPINLOCK(sdei_list_lock); |
73 | static LIST_HEAD(sdei_list); |
74 | |
75 | /* Private events are registered/enabled via IPI passing one of these */ |
76 | struct sdei_crosscall_args { |
77 | struct sdei_event *event; |
78 | atomic_t errors; |
79 | int first_error; |
80 | }; |
81 | |
82 | #define CROSSCALL_INIT(arg, event) \ |
83 | do { \ |
84 | arg.event = event; \ |
85 | arg.first_error = 0; \ |
86 | atomic_set(&arg.errors, 0); \ |
87 | } while (0) |
88 | |
89 | static inline int sdei_do_local_call(smp_call_func_t fn, |
90 | struct sdei_event *event) |
91 | { |
92 | struct sdei_crosscall_args arg; |
93 | |
94 | CROSSCALL_INIT(arg, event); |
95 | fn(&arg); |
96 | |
97 | return arg.first_error; |
98 | } |
99 | |
100 | static inline int sdei_do_cross_call(smp_call_func_t fn, |
101 | struct sdei_event *event) |
102 | { |
103 | struct sdei_crosscall_args arg; |
104 | |
105 | CROSSCALL_INIT(arg, event); |
106 | on_each_cpu(func: fn, info: &arg, wait: true); |
107 | |
108 | return arg.first_error; |
109 | } |
110 | |
111 | static inline void |
112 | sdei_cross_call_return(struct sdei_crosscall_args *arg, int err) |
113 | { |
114 | if (err && (atomic_inc_return(v: &arg->errors) == 1)) |
115 | arg->first_error = err; |
116 | } |
117 | |
118 | static int sdei_to_linux_errno(unsigned long sdei_err) |
119 | { |
120 | switch (sdei_err) { |
121 | case SDEI_NOT_SUPPORTED: |
122 | return -EOPNOTSUPP; |
123 | case SDEI_INVALID_PARAMETERS: |
124 | return -EINVAL; |
125 | case SDEI_DENIED: |
126 | return -EPERM; |
127 | case SDEI_PENDING: |
128 | return -EINPROGRESS; |
129 | case SDEI_OUT_OF_RESOURCE: |
130 | return -ENOMEM; |
131 | } |
132 | |
133 | return 0; |
134 | } |
135 | |
136 | static int invoke_sdei_fn(unsigned long function_id, unsigned long arg0, |
137 | unsigned long arg1, unsigned long arg2, |
138 | unsigned long arg3, unsigned long arg4, |
139 | u64 *result) |
140 | { |
141 | int err; |
142 | struct arm_smccc_res res; |
143 | |
144 | if (sdei_firmware_call) { |
145 | sdei_firmware_call(function_id, arg0, arg1, arg2, arg3, arg4, |
146 | &res); |
147 | err = sdei_to_linux_errno(sdei_err: res.a0); |
148 | } else { |
149 | /* |
150 | * !sdei_firmware_call means we failed to probe or called |
151 | * sdei_mark_interface_broken(). -EIO is not an error returned |
152 | * by sdei_to_linux_errno() and is used to suppress messages |
153 | * from this driver. |
154 | */ |
155 | err = -EIO; |
156 | res.a0 = SDEI_NOT_SUPPORTED; |
157 | } |
158 | |
159 | if (result) |
160 | *result = res.a0; |
161 | |
162 | return err; |
163 | } |
164 | NOKPROBE_SYMBOL(invoke_sdei_fn); |
165 | |
166 | static struct sdei_event *sdei_event_find(u32 event_num) |
167 | { |
168 | struct sdei_event *e, *found = NULL; |
169 | |
170 | lockdep_assert_held(&sdei_events_lock); |
171 | |
172 | spin_lock(lock: &sdei_list_lock); |
173 | list_for_each_entry(e, &sdei_list, list) { |
174 | if (e->event_num == event_num) { |
175 | found = e; |
176 | break; |
177 | } |
178 | } |
179 | spin_unlock(lock: &sdei_list_lock); |
180 | |
181 | return found; |
182 | } |
183 | |
184 | int sdei_api_event_context(u32 query, u64 *result) |
185 | { |
186 | return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_CONTEXT, arg0: query, arg1: 0, arg2: 0, arg3: 0, arg4: 0, |
187 | result); |
188 | } |
189 | NOKPROBE_SYMBOL(sdei_api_event_context); |
190 | |
191 | static int sdei_api_event_get_info(u32 event, u32 info, u64 *result) |
192 | { |
193 | return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_GET_INFO, arg0: event, arg1: info, arg2: 0, |
194 | arg3: 0, arg4: 0, result); |
195 | } |
196 | |
197 | static struct sdei_event *sdei_event_create(u32 event_num, |
198 | sdei_event_callback *cb, |
199 | void *cb_arg) |
200 | { |
201 | int err; |
202 | u64 result; |
203 | struct sdei_event *event; |
204 | struct sdei_registered_event *reg; |
205 | |
206 | lockdep_assert_held(&sdei_events_lock); |
207 | |
208 | event = kzalloc(size: sizeof(*event), GFP_KERNEL); |
209 | if (!event) { |
210 | err = -ENOMEM; |
211 | goto fail; |
212 | } |
213 | |
214 | INIT_LIST_HEAD(list: &event->list); |
215 | event->event_num = event_num; |
216 | |
217 | err = sdei_api_event_get_info(event: event_num, SDEI_EVENT_INFO_EV_PRIORITY, |
218 | result: &result); |
219 | if (err) |
220 | goto fail; |
221 | event->priority = result; |
222 | |
223 | err = sdei_api_event_get_info(event: event_num, SDEI_EVENT_INFO_EV_TYPE, |
224 | result: &result); |
225 | if (err) |
226 | goto fail; |
227 | event->type = result; |
228 | |
229 | if (event->type == SDEI_EVENT_TYPE_SHARED) { |
230 | reg = kzalloc(size: sizeof(*reg), GFP_KERNEL); |
231 | if (!reg) { |
232 | err = -ENOMEM; |
233 | goto fail; |
234 | } |
235 | |
236 | reg->event_num = event->event_num; |
237 | reg->priority = event->priority; |
238 | |
239 | reg->callback = cb; |
240 | reg->callback_arg = cb_arg; |
241 | event->registered = reg; |
242 | } else { |
243 | int cpu; |
244 | struct sdei_registered_event __percpu *regs; |
245 | |
246 | regs = alloc_percpu(struct sdei_registered_event); |
247 | if (!regs) { |
248 | err = -ENOMEM; |
249 | goto fail; |
250 | } |
251 | |
252 | for_each_possible_cpu(cpu) { |
253 | reg = per_cpu_ptr(regs, cpu); |
254 | |
255 | reg->event_num = event->event_num; |
256 | reg->priority = event->priority; |
257 | reg->callback = cb; |
258 | reg->callback_arg = cb_arg; |
259 | } |
260 | |
261 | event->private_registered = regs; |
262 | } |
263 | |
264 | spin_lock(lock: &sdei_list_lock); |
265 | list_add(new: &event->list, head: &sdei_list); |
266 | spin_unlock(lock: &sdei_list_lock); |
267 | |
268 | return event; |
269 | |
270 | fail: |
271 | kfree(objp: event); |
272 | return ERR_PTR(error: err); |
273 | } |
274 | |
275 | static void sdei_event_destroy_llocked(struct sdei_event *event) |
276 | { |
277 | lockdep_assert_held(&sdei_events_lock); |
278 | lockdep_assert_held(&sdei_list_lock); |
279 | |
280 | list_del(entry: &event->list); |
281 | |
282 | if (event->type == SDEI_EVENT_TYPE_SHARED) |
283 | kfree(objp: event->registered); |
284 | else |
285 | free_percpu(pdata: event->private_registered); |
286 | |
287 | kfree(objp: event); |
288 | } |
289 | |
290 | static void sdei_event_destroy(struct sdei_event *event) |
291 | { |
292 | spin_lock(lock: &sdei_list_lock); |
293 | sdei_event_destroy_llocked(event); |
294 | spin_unlock(lock: &sdei_list_lock); |
295 | } |
296 | |
297 | static int sdei_api_get_version(u64 *version) |
298 | { |
299 | return invoke_sdei_fn(SDEI_1_0_FN_SDEI_VERSION, arg0: 0, arg1: 0, arg2: 0, arg3: 0, arg4: 0, result: version); |
300 | } |
301 | |
302 | int sdei_mask_local_cpu(void) |
303 | { |
304 | int err; |
305 | |
306 | err = invoke_sdei_fn(SDEI_1_0_FN_SDEI_PE_MASK, arg0: 0, arg1: 0, arg2: 0, arg3: 0, arg4: 0, NULL); |
307 | if (err && err != -EIO) { |
308 | pr_warn_once("failed to mask CPU[%u]: %d\n" , |
309 | smp_processor_id(), err); |
310 | return err; |
311 | } |
312 | |
313 | return 0; |
314 | } |
315 | |
316 | static void _ipi_mask_cpu(void *ignored) |
317 | { |
318 | WARN_ON_ONCE(preemptible()); |
319 | sdei_mask_local_cpu(); |
320 | } |
321 | |
322 | int sdei_unmask_local_cpu(void) |
323 | { |
324 | int err; |
325 | |
326 | err = invoke_sdei_fn(SDEI_1_0_FN_SDEI_PE_UNMASK, arg0: 0, arg1: 0, arg2: 0, arg3: 0, arg4: 0, NULL); |
327 | if (err && err != -EIO) { |
328 | pr_warn_once("failed to unmask CPU[%u]: %d\n" , |
329 | smp_processor_id(), err); |
330 | return err; |
331 | } |
332 | |
333 | return 0; |
334 | } |
335 | |
336 | static void _ipi_unmask_cpu(void *ignored) |
337 | { |
338 | WARN_ON_ONCE(preemptible()); |
339 | sdei_unmask_local_cpu(); |
340 | } |
341 | |
342 | static void _ipi_private_reset(void *ignored) |
343 | { |
344 | int err; |
345 | |
346 | WARN_ON_ONCE(preemptible()); |
347 | |
348 | err = invoke_sdei_fn(SDEI_1_0_FN_SDEI_PRIVATE_RESET, arg0: 0, arg1: 0, arg2: 0, arg3: 0, arg4: 0, |
349 | NULL); |
350 | if (err && err != -EIO) |
351 | pr_warn_once("failed to reset CPU[%u]: %d\n" , |
352 | smp_processor_id(), err); |
353 | } |
354 | |
355 | static int sdei_api_shared_reset(void) |
356 | { |
357 | return invoke_sdei_fn(SDEI_1_0_FN_SDEI_SHARED_RESET, arg0: 0, arg1: 0, arg2: 0, arg3: 0, arg4: 0, |
358 | NULL); |
359 | } |
360 | |
361 | static void sdei_mark_interface_broken(void) |
362 | { |
363 | pr_err("disabling SDEI firmware interface\n" ); |
364 | on_each_cpu(func: &_ipi_mask_cpu, NULL, wait: true); |
365 | sdei_firmware_call = NULL; |
366 | } |
367 | |
368 | static int sdei_platform_reset(void) |
369 | { |
370 | int err; |
371 | |
372 | on_each_cpu(func: &_ipi_private_reset, NULL, wait: true); |
373 | err = sdei_api_shared_reset(); |
374 | if (err) { |
375 | pr_err("Failed to reset platform: %d\n" , err); |
376 | sdei_mark_interface_broken(); |
377 | } |
378 | |
379 | return err; |
380 | } |
381 | |
382 | static int sdei_api_event_enable(u32 event_num) |
383 | { |
384 | return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_ENABLE, arg0: event_num, arg1: 0, arg2: 0, arg3: 0, |
385 | arg4: 0, NULL); |
386 | } |
387 | |
388 | /* Called directly by the hotplug callbacks */ |
389 | static void _local_event_enable(void *data) |
390 | { |
391 | int err; |
392 | struct sdei_crosscall_args *arg = data; |
393 | |
394 | err = sdei_api_event_enable(event_num: arg->event->event_num); |
395 | |
396 | sdei_cross_call_return(arg, err); |
397 | } |
398 | |
399 | int sdei_event_enable(u32 event_num) |
400 | { |
401 | int err = -EINVAL; |
402 | struct sdei_event *event; |
403 | |
404 | mutex_lock(&sdei_events_lock); |
405 | event = sdei_event_find(event_num); |
406 | if (!event) { |
407 | mutex_unlock(lock: &sdei_events_lock); |
408 | return -ENOENT; |
409 | } |
410 | |
411 | |
412 | cpus_read_lock(); |
413 | if (event->type == SDEI_EVENT_TYPE_SHARED) |
414 | err = sdei_api_event_enable(event_num: event->event_num); |
415 | else |
416 | err = sdei_do_cross_call(fn: _local_event_enable, event); |
417 | |
418 | if (!err) { |
419 | spin_lock(lock: &sdei_list_lock); |
420 | event->reenable = true; |
421 | spin_unlock(lock: &sdei_list_lock); |
422 | } |
423 | cpus_read_unlock(); |
424 | mutex_unlock(lock: &sdei_events_lock); |
425 | |
426 | return err; |
427 | } |
428 | |
429 | static int sdei_api_event_disable(u32 event_num) |
430 | { |
431 | return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_DISABLE, arg0: event_num, arg1: 0, arg2: 0, |
432 | arg3: 0, arg4: 0, NULL); |
433 | } |
434 | |
435 | static void _ipi_event_disable(void *data) |
436 | { |
437 | int err; |
438 | struct sdei_crosscall_args *arg = data; |
439 | |
440 | err = sdei_api_event_disable(event_num: arg->event->event_num); |
441 | |
442 | sdei_cross_call_return(arg, err); |
443 | } |
444 | |
445 | int sdei_event_disable(u32 event_num) |
446 | { |
447 | int err = -EINVAL; |
448 | struct sdei_event *event; |
449 | |
450 | mutex_lock(&sdei_events_lock); |
451 | event = sdei_event_find(event_num); |
452 | if (!event) { |
453 | mutex_unlock(lock: &sdei_events_lock); |
454 | return -ENOENT; |
455 | } |
456 | |
457 | spin_lock(lock: &sdei_list_lock); |
458 | event->reenable = false; |
459 | spin_unlock(lock: &sdei_list_lock); |
460 | |
461 | if (event->type == SDEI_EVENT_TYPE_SHARED) |
462 | err = sdei_api_event_disable(event_num: event->event_num); |
463 | else |
464 | err = sdei_do_cross_call(fn: _ipi_event_disable, event); |
465 | mutex_unlock(lock: &sdei_events_lock); |
466 | |
467 | return err; |
468 | } |
469 | |
470 | static int sdei_api_event_unregister(u32 event_num) |
471 | { |
472 | return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_UNREGISTER, arg0: event_num, arg1: 0, |
473 | arg2: 0, arg3: 0, arg4: 0, NULL); |
474 | } |
475 | |
476 | /* Called directly by the hotplug callbacks */ |
477 | static void _local_event_unregister(void *data) |
478 | { |
479 | int err; |
480 | struct sdei_crosscall_args *arg = data; |
481 | |
482 | err = sdei_api_event_unregister(event_num: arg->event->event_num); |
483 | |
484 | sdei_cross_call_return(arg, err); |
485 | } |
486 | |
487 | int sdei_event_unregister(u32 event_num) |
488 | { |
489 | int err; |
490 | struct sdei_event *event; |
491 | |
492 | WARN_ON(in_nmi()); |
493 | |
494 | mutex_lock(&sdei_events_lock); |
495 | event = sdei_event_find(event_num); |
496 | if (!event) { |
497 | pr_warn("Event %u not registered\n" , event_num); |
498 | err = -ENOENT; |
499 | goto unlock; |
500 | } |
501 | |
502 | spin_lock(lock: &sdei_list_lock); |
503 | event->reregister = false; |
504 | event->reenable = false; |
505 | spin_unlock(lock: &sdei_list_lock); |
506 | |
507 | if (event->type == SDEI_EVENT_TYPE_SHARED) |
508 | err = sdei_api_event_unregister(event_num: event->event_num); |
509 | else |
510 | err = sdei_do_cross_call(fn: _local_event_unregister, event); |
511 | |
512 | if (err) |
513 | goto unlock; |
514 | |
515 | sdei_event_destroy(event); |
516 | unlock: |
517 | mutex_unlock(lock: &sdei_events_lock); |
518 | |
519 | return err; |
520 | } |
521 | |
522 | /* |
523 | * unregister events, but don't destroy them as they are re-registered by |
524 | * sdei_reregister_shared(). |
525 | */ |
526 | static int sdei_unregister_shared(void) |
527 | { |
528 | int err = 0; |
529 | struct sdei_event *event; |
530 | |
531 | mutex_lock(&sdei_events_lock); |
532 | spin_lock(lock: &sdei_list_lock); |
533 | list_for_each_entry(event, &sdei_list, list) { |
534 | if (event->type != SDEI_EVENT_TYPE_SHARED) |
535 | continue; |
536 | |
537 | err = sdei_api_event_unregister(event_num: event->event_num); |
538 | if (err) |
539 | break; |
540 | } |
541 | spin_unlock(lock: &sdei_list_lock); |
542 | mutex_unlock(lock: &sdei_events_lock); |
543 | |
544 | return err; |
545 | } |
546 | |
547 | static int sdei_api_event_register(u32 event_num, unsigned long entry_point, |
548 | void *arg, u64 flags, u64 affinity) |
549 | { |
550 | return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_REGISTER, arg0: event_num, |
551 | arg1: (unsigned long)entry_point, arg2: (unsigned long)arg, |
552 | arg3: flags, arg4: affinity, NULL); |
553 | } |
554 | |
555 | /* Called directly by the hotplug callbacks */ |
556 | static void _local_event_register(void *data) |
557 | { |
558 | int err; |
559 | struct sdei_registered_event *reg; |
560 | struct sdei_crosscall_args *arg = data; |
561 | |
562 | reg = per_cpu_ptr(arg->event->private_registered, smp_processor_id()); |
563 | err = sdei_api_event_register(event_num: arg->event->event_num, entry_point: sdei_entry_point, |
564 | arg: reg, flags: 0, affinity: 0); |
565 | |
566 | sdei_cross_call_return(arg, err); |
567 | } |
568 | |
569 | int sdei_event_register(u32 event_num, sdei_event_callback *cb, void *arg) |
570 | { |
571 | int err; |
572 | struct sdei_event *event; |
573 | |
574 | WARN_ON(in_nmi()); |
575 | |
576 | mutex_lock(&sdei_events_lock); |
577 | if (sdei_event_find(event_num)) { |
578 | pr_warn("Event %u already registered\n" , event_num); |
579 | err = -EBUSY; |
580 | goto unlock; |
581 | } |
582 | |
583 | event = sdei_event_create(event_num, cb, cb_arg: arg); |
584 | if (IS_ERR(ptr: event)) { |
585 | err = PTR_ERR(ptr: event); |
586 | pr_warn("Failed to create event %u: %d\n" , event_num, err); |
587 | goto unlock; |
588 | } |
589 | |
590 | cpus_read_lock(); |
591 | if (event->type == SDEI_EVENT_TYPE_SHARED) { |
592 | err = sdei_api_event_register(event_num: event->event_num, |
593 | entry_point: sdei_entry_point, |
594 | arg: event->registered, |
595 | SDEI_EVENT_REGISTER_RM_ANY, affinity: 0); |
596 | } else { |
597 | err = sdei_do_cross_call(fn: _local_event_register, event); |
598 | if (err) |
599 | sdei_do_cross_call(fn: _local_event_unregister, event); |
600 | } |
601 | |
602 | if (err) { |
603 | sdei_event_destroy(event); |
604 | pr_warn("Failed to register event %u: %d\n" , event_num, err); |
605 | goto cpu_unlock; |
606 | } |
607 | |
608 | spin_lock(lock: &sdei_list_lock); |
609 | event->reregister = true; |
610 | spin_unlock(lock: &sdei_list_lock); |
611 | cpu_unlock: |
612 | cpus_read_unlock(); |
613 | unlock: |
614 | mutex_unlock(lock: &sdei_events_lock); |
615 | return err; |
616 | } |
617 | |
618 | static int sdei_reregister_shared(void) |
619 | { |
620 | int err = 0; |
621 | struct sdei_event *event; |
622 | |
623 | mutex_lock(&sdei_events_lock); |
624 | spin_lock(lock: &sdei_list_lock); |
625 | list_for_each_entry(event, &sdei_list, list) { |
626 | if (event->type != SDEI_EVENT_TYPE_SHARED) |
627 | continue; |
628 | |
629 | if (event->reregister) { |
630 | err = sdei_api_event_register(event_num: event->event_num, |
631 | entry_point: sdei_entry_point, arg: event->registered, |
632 | SDEI_EVENT_REGISTER_RM_ANY, affinity: 0); |
633 | if (err) { |
634 | pr_err("Failed to re-register event %u\n" , |
635 | event->event_num); |
636 | sdei_event_destroy_llocked(event); |
637 | break; |
638 | } |
639 | } |
640 | |
641 | if (event->reenable) { |
642 | err = sdei_api_event_enable(event_num: event->event_num); |
643 | if (err) { |
644 | pr_err("Failed to re-enable event %u\n" , |
645 | event->event_num); |
646 | break; |
647 | } |
648 | } |
649 | } |
650 | spin_unlock(lock: &sdei_list_lock); |
651 | mutex_unlock(lock: &sdei_events_lock); |
652 | |
653 | return err; |
654 | } |
655 | |
656 | static int sdei_cpuhp_down(unsigned int cpu) |
657 | { |
658 | struct sdei_event *event; |
659 | int err; |
660 | |
661 | /* un-register private events */ |
662 | spin_lock(lock: &sdei_list_lock); |
663 | list_for_each_entry(event, &sdei_list, list) { |
664 | if (event->type == SDEI_EVENT_TYPE_SHARED) |
665 | continue; |
666 | |
667 | err = sdei_do_local_call(fn: _local_event_unregister, event); |
668 | if (err) { |
669 | pr_err("Failed to unregister event %u: %d\n" , |
670 | event->event_num, err); |
671 | } |
672 | } |
673 | spin_unlock(lock: &sdei_list_lock); |
674 | |
675 | return sdei_mask_local_cpu(); |
676 | } |
677 | |
678 | static int sdei_cpuhp_up(unsigned int cpu) |
679 | { |
680 | struct sdei_event *event; |
681 | int err; |
682 | |
683 | /* re-register/enable private events */ |
684 | spin_lock(lock: &sdei_list_lock); |
685 | list_for_each_entry(event, &sdei_list, list) { |
686 | if (event->type == SDEI_EVENT_TYPE_SHARED) |
687 | continue; |
688 | |
689 | if (event->reregister) { |
690 | err = sdei_do_local_call(fn: _local_event_register, event); |
691 | if (err) { |
692 | pr_err("Failed to re-register event %u: %d\n" , |
693 | event->event_num, err); |
694 | } |
695 | } |
696 | |
697 | if (event->reenable) { |
698 | err = sdei_do_local_call(fn: _local_event_enable, event); |
699 | if (err) { |
700 | pr_err("Failed to re-enable event %u: %d\n" , |
701 | event->event_num, err); |
702 | } |
703 | } |
704 | } |
705 | spin_unlock(lock: &sdei_list_lock); |
706 | |
707 | return sdei_unmask_local_cpu(); |
708 | } |
709 | |
710 | /* When entering idle, mask/unmask events for this cpu */ |
711 | static int sdei_pm_notifier(struct notifier_block *nb, unsigned long action, |
712 | void *data) |
713 | { |
714 | int rv; |
715 | |
716 | WARN_ON_ONCE(preemptible()); |
717 | |
718 | switch (action) { |
719 | case CPU_PM_ENTER: |
720 | rv = sdei_mask_local_cpu(); |
721 | break; |
722 | case CPU_PM_EXIT: |
723 | case CPU_PM_ENTER_FAILED: |
724 | rv = sdei_unmask_local_cpu(); |
725 | break; |
726 | default: |
727 | return NOTIFY_DONE; |
728 | } |
729 | |
730 | if (rv) |
731 | return notifier_from_errno(err: rv); |
732 | |
733 | return NOTIFY_OK; |
734 | } |
735 | |
736 | static struct notifier_block sdei_pm_nb = { |
737 | .notifier_call = sdei_pm_notifier, |
738 | }; |
739 | |
740 | static int sdei_device_suspend(struct device *dev) |
741 | { |
742 | on_each_cpu(func: _ipi_mask_cpu, NULL, wait: true); |
743 | |
744 | return 0; |
745 | } |
746 | |
747 | static int sdei_device_resume(struct device *dev) |
748 | { |
749 | on_each_cpu(func: _ipi_unmask_cpu, NULL, wait: true); |
750 | |
751 | return 0; |
752 | } |
753 | |
754 | /* |
755 | * We need all events to be reregistered when we resume from hibernate. |
756 | * |
757 | * The sequence is freeze->thaw. Reboot. freeze->restore. We unregister |
758 | * events during freeze, then re-register and re-enable them during thaw |
759 | * and restore. |
760 | */ |
761 | static int sdei_device_freeze(struct device *dev) |
762 | { |
763 | int err; |
764 | |
765 | /* unregister private events */ |
766 | cpuhp_remove_state(state: sdei_entry_point); |
767 | |
768 | err = sdei_unregister_shared(); |
769 | if (err) |
770 | return err; |
771 | |
772 | return 0; |
773 | } |
774 | |
775 | static int sdei_device_thaw(struct device *dev) |
776 | { |
777 | int err; |
778 | |
779 | /* re-register shared events */ |
780 | err = sdei_reregister_shared(); |
781 | if (err) { |
782 | pr_warn("Failed to re-register shared events...\n" ); |
783 | sdei_mark_interface_broken(); |
784 | return err; |
785 | } |
786 | |
787 | err = cpuhp_setup_state(state: CPUHP_AP_ONLINE_DYN, name: "SDEI" , |
788 | startup: &sdei_cpuhp_up, teardown: &sdei_cpuhp_down); |
789 | if (err < 0) { |
790 | pr_warn("Failed to re-register CPU hotplug notifier...\n" ); |
791 | return err; |
792 | } |
793 | |
794 | sdei_hp_state = err; |
795 | return 0; |
796 | } |
797 | |
798 | static int sdei_device_restore(struct device *dev) |
799 | { |
800 | int err; |
801 | |
802 | err = sdei_platform_reset(); |
803 | if (err) |
804 | return err; |
805 | |
806 | return sdei_device_thaw(dev); |
807 | } |
808 | |
809 | static const struct dev_pm_ops sdei_pm_ops = { |
810 | .suspend = sdei_device_suspend, |
811 | .resume = sdei_device_resume, |
812 | .freeze = sdei_device_freeze, |
813 | .thaw = sdei_device_thaw, |
814 | .restore = sdei_device_restore, |
815 | }; |
816 | |
817 | /* |
818 | * Mask all CPUs and unregister all events on panic, reboot or kexec. |
819 | */ |
820 | static int sdei_reboot_notifier(struct notifier_block *nb, unsigned long action, |
821 | void *data) |
822 | { |
823 | /* |
824 | * We are going to reset the interface, after this there is no point |
825 | * doing work when we take CPUs offline. |
826 | */ |
827 | cpuhp_remove_state(state: sdei_hp_state); |
828 | |
829 | sdei_platform_reset(); |
830 | |
831 | return NOTIFY_OK; |
832 | } |
833 | |
834 | static struct notifier_block sdei_reboot_nb = { |
835 | .notifier_call = sdei_reboot_notifier, |
836 | }; |
837 | |
838 | static void sdei_smccc_smc(unsigned long function_id, |
839 | unsigned long arg0, unsigned long arg1, |
840 | unsigned long arg2, unsigned long arg3, |
841 | unsigned long arg4, struct arm_smccc_res *res) |
842 | { |
843 | arm_smccc_smc(function_id, arg0, arg1, arg2, arg3, arg4, 0, 0, res); |
844 | } |
845 | NOKPROBE_SYMBOL(sdei_smccc_smc); |
846 | |
847 | static void sdei_smccc_hvc(unsigned long function_id, |
848 | unsigned long arg0, unsigned long arg1, |
849 | unsigned long arg2, unsigned long arg3, |
850 | unsigned long arg4, struct arm_smccc_res *res) |
851 | { |
852 | arm_smccc_hvc(function_id, arg0, arg1, arg2, arg3, arg4, 0, 0, res); |
853 | } |
854 | NOKPROBE_SYMBOL(sdei_smccc_hvc); |
855 | |
856 | int sdei_register_ghes(struct ghes *ghes, sdei_event_callback *normal_cb, |
857 | sdei_event_callback *critical_cb) |
858 | { |
859 | int err; |
860 | u64 result; |
861 | u32 event_num; |
862 | sdei_event_callback *cb; |
863 | |
864 | if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES)) |
865 | return -EOPNOTSUPP; |
866 | |
867 | event_num = ghes->generic->notify.vector; |
868 | if (event_num == 0) { |
869 | /* |
870 | * Event 0 is reserved by the specification for |
871 | * SDEI_EVENT_SIGNAL. |
872 | */ |
873 | return -EINVAL; |
874 | } |
875 | |
876 | err = sdei_api_event_get_info(event: event_num, SDEI_EVENT_INFO_EV_PRIORITY, |
877 | result: &result); |
878 | if (err) |
879 | return err; |
880 | |
881 | if (result == SDEI_EVENT_PRIORITY_CRITICAL) |
882 | cb = critical_cb; |
883 | else |
884 | cb = normal_cb; |
885 | |
886 | err = sdei_event_register(event_num, cb, arg: ghes); |
887 | if (!err) |
888 | err = sdei_event_enable(event_num); |
889 | |
890 | return err; |
891 | } |
892 | |
893 | int sdei_unregister_ghes(struct ghes *ghes) |
894 | { |
895 | int i; |
896 | int err; |
897 | u32 event_num = ghes->generic->notify.vector; |
898 | |
899 | might_sleep(); |
900 | |
901 | if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES)) |
902 | return -EOPNOTSUPP; |
903 | |
904 | /* |
905 | * The event may be running on another CPU. Disable it |
906 | * to stop new events, then try to unregister a few times. |
907 | */ |
908 | err = sdei_event_disable(event_num); |
909 | if (err) |
910 | return err; |
911 | |
912 | for (i = 0; i < 3; i++) { |
913 | err = sdei_event_unregister(event_num); |
914 | if (err != -EINPROGRESS) |
915 | break; |
916 | |
917 | schedule(); |
918 | } |
919 | |
920 | return err; |
921 | } |
922 | |
923 | static int sdei_get_conduit(struct platform_device *pdev) |
924 | { |
925 | const char *method; |
926 | struct device_node *np = pdev->dev.of_node; |
927 | |
928 | sdei_firmware_call = NULL; |
929 | if (np) { |
930 | if (of_property_read_string(np, propname: "method" , out_string: &method)) { |
931 | pr_warn("missing \"method\" property\n" ); |
932 | return SMCCC_CONDUIT_NONE; |
933 | } |
934 | |
935 | if (!strcmp("hvc" , method)) { |
936 | sdei_firmware_call = &sdei_smccc_hvc; |
937 | return SMCCC_CONDUIT_HVC; |
938 | } else if (!strcmp("smc" , method)) { |
939 | sdei_firmware_call = &sdei_smccc_smc; |
940 | return SMCCC_CONDUIT_SMC; |
941 | } |
942 | |
943 | pr_warn("invalid \"method\" property: %s\n" , method); |
944 | } else if (!acpi_disabled) { |
945 | if (acpi_psci_use_hvc()) { |
946 | sdei_firmware_call = &sdei_smccc_hvc; |
947 | return SMCCC_CONDUIT_HVC; |
948 | } else { |
949 | sdei_firmware_call = &sdei_smccc_smc; |
950 | return SMCCC_CONDUIT_SMC; |
951 | } |
952 | } |
953 | |
954 | return SMCCC_CONDUIT_NONE; |
955 | } |
956 | |
957 | static int sdei_probe(struct platform_device *pdev) |
958 | { |
959 | int err; |
960 | u64 ver = 0; |
961 | int conduit; |
962 | |
963 | conduit = sdei_get_conduit(pdev); |
964 | if (!sdei_firmware_call) |
965 | return 0; |
966 | |
967 | err = sdei_api_get_version(version: &ver); |
968 | if (err) { |
969 | pr_err("Failed to get SDEI version: %d\n" , err); |
970 | sdei_mark_interface_broken(); |
971 | return err; |
972 | } |
973 | |
974 | pr_info("SDEIv%d.%d (0x%x) detected in firmware.\n" , |
975 | (int)SDEI_VERSION_MAJOR(ver), (int)SDEI_VERSION_MINOR(ver), |
976 | (int)SDEI_VERSION_VENDOR(ver)); |
977 | |
978 | if (SDEI_VERSION_MAJOR(ver) != 1) { |
979 | pr_warn("Conflicting SDEI version detected.\n" ); |
980 | sdei_mark_interface_broken(); |
981 | return -EINVAL; |
982 | } |
983 | |
984 | err = sdei_platform_reset(); |
985 | if (err) |
986 | return err; |
987 | |
988 | sdei_entry_point = sdei_arch_get_entry_point(conduit); |
989 | if (!sdei_entry_point) { |
990 | /* Not supported due to hardware or boot configuration */ |
991 | sdei_mark_interface_broken(); |
992 | return 0; |
993 | } |
994 | |
995 | err = cpu_pm_register_notifier(nb: &sdei_pm_nb); |
996 | if (err) { |
997 | pr_warn("Failed to register CPU PM notifier...\n" ); |
998 | goto error; |
999 | } |
1000 | |
1001 | err = register_reboot_notifier(&sdei_reboot_nb); |
1002 | if (err) { |
1003 | pr_warn("Failed to register reboot notifier...\n" ); |
1004 | goto remove_cpupm; |
1005 | } |
1006 | |
1007 | err = cpuhp_setup_state(state: CPUHP_AP_ONLINE_DYN, name: "SDEI" , |
1008 | startup: &sdei_cpuhp_up, teardown: &sdei_cpuhp_down); |
1009 | if (err < 0) { |
1010 | pr_warn("Failed to register CPU hotplug notifier...\n" ); |
1011 | goto remove_reboot; |
1012 | } |
1013 | |
1014 | sdei_hp_state = err; |
1015 | |
1016 | return 0; |
1017 | |
1018 | remove_reboot: |
1019 | unregister_reboot_notifier(&sdei_reboot_nb); |
1020 | |
1021 | remove_cpupm: |
1022 | cpu_pm_unregister_notifier(nb: &sdei_pm_nb); |
1023 | |
1024 | error: |
1025 | sdei_mark_interface_broken(); |
1026 | return err; |
1027 | } |
1028 | |
1029 | static const struct of_device_id sdei_of_match[] = { |
1030 | { .compatible = "arm,sdei-1.0" }, |
1031 | {} |
1032 | }; |
1033 | |
1034 | static struct platform_driver sdei_driver = { |
1035 | .driver = { |
1036 | .name = "sdei" , |
1037 | .pm = &sdei_pm_ops, |
1038 | .of_match_table = sdei_of_match, |
1039 | }, |
1040 | .probe = sdei_probe, |
1041 | }; |
1042 | |
1043 | static bool __init sdei_present_acpi(void) |
1044 | { |
1045 | acpi_status status; |
1046 | struct acpi_table_header *; |
1047 | |
1048 | if (acpi_disabled) |
1049 | return false; |
1050 | |
1051 | status = acpi_get_table(ACPI_SIG_SDEI, instance: 0, out_table: &sdei_table_header); |
1052 | if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) { |
1053 | const char *msg = acpi_format_exception(exception: status); |
1054 | |
1055 | pr_info("Failed to get ACPI:SDEI table, %s\n" , msg); |
1056 | } |
1057 | if (ACPI_FAILURE(status)) |
1058 | return false; |
1059 | |
1060 | acpi_put_table(table: sdei_table_header); |
1061 | |
1062 | return true; |
1063 | } |
1064 | |
1065 | void __init sdei_init(void) |
1066 | { |
1067 | struct platform_device *pdev; |
1068 | int ret; |
1069 | |
1070 | ret = platform_driver_register(&sdei_driver); |
1071 | if (ret || !sdei_present_acpi()) |
1072 | return; |
1073 | |
1074 | pdev = platform_device_register_simple(name: sdei_driver.driver.name, |
1075 | id: 0, NULL, num: 0); |
1076 | if (IS_ERR(ptr: pdev)) { |
1077 | ret = PTR_ERR(ptr: pdev); |
1078 | platform_driver_unregister(&sdei_driver); |
1079 | pr_info("Failed to register ACPI:SDEI platform device %d\n" , |
1080 | ret); |
1081 | } |
1082 | } |
1083 | |
1084 | int sdei_event_handler(struct pt_regs *regs, |
1085 | struct sdei_registered_event *arg) |
1086 | { |
1087 | int err; |
1088 | u32 event_num = arg->event_num; |
1089 | |
1090 | err = arg->callback(event_num, regs, arg->callback_arg); |
1091 | if (err) |
1092 | pr_err_ratelimited("event %u on CPU %u failed with error: %d\n" , |
1093 | event_num, smp_processor_id(), err); |
1094 | |
1095 | return err; |
1096 | } |
1097 | NOKPROBE_SYMBOL(sdei_event_handler); |
1098 | |
1099 | void sdei_handler_abort(void) |
1100 | { |
1101 | /* |
1102 | * If the crash happened in an SDEI event handler then we need to |
1103 | * finish the handler with the firmware so that we can have working |
1104 | * interrupts in the crash kernel. |
1105 | */ |
1106 | if (__this_cpu_read(sdei_active_critical_event)) { |
1107 | pr_warn("still in SDEI critical event context, attempting to finish handler.\n" ); |
1108 | __sdei_handler_abort(); |
1109 | __this_cpu_write(sdei_active_critical_event, NULL); |
1110 | } |
1111 | if (__this_cpu_read(sdei_active_normal_event)) { |
1112 | pr_warn("still in SDEI normal event context, attempting to finish handler.\n" ); |
1113 | __sdei_handler_abort(); |
1114 | __this_cpu_write(sdei_active_normal_event, NULL); |
1115 | } |
1116 | } |
1117 | |