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ad6eb31e JM |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | // Copyright (C) 2017 Arm Ltd. | |
3 | #define pr_fmt(fmt) "sdei: " fmt | |
4 | ||
f96935d3 | 5 | #include <acpi/ghes.h> |
ad6eb31e JM |
6 | #include <linux/acpi.h> |
7 | #include <linux/arm_sdei.h> | |
8 | #include <linux/arm-smccc.h> | |
f92b5462 | 9 | #include <linux/atomic.h> |
ad6eb31e JM |
10 | #include <linux/bitops.h> |
11 | #include <linux/compiler.h> | |
da351827 | 12 | #include <linux/cpuhotplug.h> |
f92b5462 | 13 | #include <linux/cpu.h> |
da351827 | 14 | #include <linux/cpu_pm.h> |
ad6eb31e JM |
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> | |
da351827 | 22 | #include <linux/notifier.h> |
ad6eb31e JM |
23 | #include <linux/of.h> |
24 | #include <linux/of_platform.h> | |
25 | #include <linux/percpu.h> | |
26 | #include <linux/platform_device.h> | |
da351827 | 27 | #include <linux/pm.h> |
ad6eb31e JM |
28 | #include <linux/ptrace.h> |
29 | #include <linux/preempt.h> | |
da351827 | 30 | #include <linux/reboot.h> |
ad6eb31e JM |
31 | #include <linux/slab.h> |
32 | #include <linux/smp.h> | |
33 | #include <linux/spinlock.h> | |
34 | #include <linux/uaccess.h> | |
35 | ||
36 | /* | |
37 | * The call to use to reach the firmware. | |
38 | */ | |
39 | static asmlinkage void (*sdei_firmware_call)(unsigned long function_id, | |
40 | unsigned long arg0, unsigned long arg1, | |
41 | unsigned long arg2, unsigned long arg3, | |
42 | unsigned long arg4, struct arm_smccc_res *res); | |
43 | ||
44 | /* entry point from firmware to arch asm code */ | |
45 | static unsigned long sdei_entry_point; | |
46 | ||
47 | struct sdei_event { | |
da351827 | 48 | /* These three are protected by the sdei_list_lock */ |
ad6eb31e | 49 | struct list_head list; |
da351827 JM |
50 | bool reregister; |
51 | bool reenable; | |
52 | ||
ad6eb31e JM |
53 | u32 event_num; |
54 | u8 type; | |
55 | u8 priority; | |
56 | ||
57 | /* This pointer is handed to firmware as the event argument. */ | |
f92b5462 JM |
58 | union { |
59 | /* Shared events */ | |
60 | struct sdei_registered_event *registered; | |
61 | ||
62 | /* CPU private events */ | |
63 | struct sdei_registered_event __percpu *private_registered; | |
64 | }; | |
ad6eb31e JM |
65 | }; |
66 | ||
67 | /* Take the mutex for any API call or modification. Take the mutex first. */ | |
68 | static DEFINE_MUTEX(sdei_events_lock); | |
69 | ||
70 | /* and then hold this when modifying the list */ | |
71 | static DEFINE_SPINLOCK(sdei_list_lock); | |
72 | static LIST_HEAD(sdei_list); | |
73 | ||
f92b5462 JM |
74 | /* Private events are registered/enabled via IPI passing one of these */ |
75 | struct sdei_crosscall_args { | |
76 | struct sdei_event *event; | |
77 | atomic_t errors; | |
78 | int first_error; | |
79 | }; | |
80 | ||
81 | #define CROSSCALL_INIT(arg, event) (arg.event = event, \ | |
82 | arg.first_error = 0, \ | |
83 | atomic_set(&arg.errors, 0)) | |
84 | ||
85 | static inline int sdei_do_cross_call(void *fn, struct sdei_event * event) | |
86 | { | |
87 | struct sdei_crosscall_args arg; | |
88 | ||
89 | CROSSCALL_INIT(arg, event); | |
90 | on_each_cpu(fn, &arg, true); | |
91 | ||
92 | return arg.first_error; | |
93 | } | |
94 | ||
95 | static inline void | |
96 | sdei_cross_call_return(struct sdei_crosscall_args *arg, int err) | |
97 | { | |
98 | if (err && (atomic_inc_return(&arg->errors) == 1)) | |
99 | arg->first_error = err; | |
100 | } | |
101 | ||
ad6eb31e JM |
102 | static int sdei_to_linux_errno(unsigned long sdei_err) |
103 | { | |
104 | switch (sdei_err) { | |
105 | case SDEI_NOT_SUPPORTED: | |
106 | return -EOPNOTSUPP; | |
107 | case SDEI_INVALID_PARAMETERS: | |
108 | return -EINVAL; | |
109 | case SDEI_DENIED: | |
110 | return -EPERM; | |
111 | case SDEI_PENDING: | |
112 | return -EINPROGRESS; | |
113 | case SDEI_OUT_OF_RESOURCE: | |
114 | return -ENOMEM; | |
115 | } | |
116 | ||
117 | /* Not an error value ... */ | |
118 | return sdei_err; | |
119 | } | |
120 | ||
121 | /* | |
122 | * If x0 is any of these values, then the call failed, use sdei_to_linux_errno() | |
123 | * to translate. | |
124 | */ | |
125 | static int sdei_is_err(struct arm_smccc_res *res) | |
126 | { | |
127 | switch (res->a0) { | |
128 | case SDEI_NOT_SUPPORTED: | |
129 | case SDEI_INVALID_PARAMETERS: | |
130 | case SDEI_DENIED: | |
131 | case SDEI_PENDING: | |
132 | case SDEI_OUT_OF_RESOURCE: | |
133 | return true; | |
134 | } | |
135 | ||
136 | return false; | |
137 | } | |
138 | ||
139 | static int invoke_sdei_fn(unsigned long function_id, unsigned long arg0, | |
140 | unsigned long arg1, unsigned long arg2, | |
141 | unsigned long arg3, unsigned long arg4, | |
142 | u64 *result) | |
143 | { | |
144 | int err = 0; | |
145 | struct arm_smccc_res res; | |
146 | ||
147 | if (sdei_firmware_call) { | |
148 | sdei_firmware_call(function_id, arg0, arg1, arg2, arg3, arg4, | |
149 | &res); | |
150 | if (sdei_is_err(&res)) | |
151 | err = sdei_to_linux_errno(res.a0); | |
152 | } else { | |
153 | /* | |
154 | * !sdei_firmware_call means we failed to probe or called | |
155 | * sdei_mark_interface_broken(). -EIO is not an error returned | |
156 | * by sdei_to_linux_errno() and is used to suppress messages | |
157 | * from this driver. | |
158 | */ | |
159 | err = -EIO; | |
160 | res.a0 = SDEI_NOT_SUPPORTED; | |
161 | } | |
162 | ||
163 | if (result) | |
164 | *result = res.a0; | |
165 | ||
166 | return err; | |
167 | } | |
2f1d4e24 | 168 | NOKPROBE_SYMBOL(invoke_sdei_fn); |
ad6eb31e JM |
169 | |
170 | static struct sdei_event *sdei_event_find(u32 event_num) | |
171 | { | |
172 | struct sdei_event *e, *found = NULL; | |
173 | ||
174 | lockdep_assert_held(&sdei_events_lock); | |
175 | ||
176 | spin_lock(&sdei_list_lock); | |
177 | list_for_each_entry(e, &sdei_list, list) { | |
178 | if (e->event_num == event_num) { | |
179 | found = e; | |
180 | break; | |
181 | } | |
182 | } | |
183 | spin_unlock(&sdei_list_lock); | |
184 | ||
185 | return found; | |
186 | } | |
187 | ||
188 | int sdei_api_event_context(u32 query, u64 *result) | |
189 | { | |
190 | return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_CONTEXT, query, 0, 0, 0, 0, | |
191 | result); | |
192 | } | |
193 | NOKPROBE_SYMBOL(sdei_api_event_context); | |
194 | ||
195 | static int sdei_api_event_get_info(u32 event, u32 info, u64 *result) | |
196 | { | |
197 | return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_GET_INFO, event, info, 0, | |
198 | 0, 0, result); | |
199 | } | |
200 | ||
201 | static struct sdei_event *sdei_event_create(u32 event_num, | |
202 | sdei_event_callback *cb, | |
203 | void *cb_arg) | |
204 | { | |
205 | int err; | |
206 | u64 result; | |
207 | struct sdei_event *event; | |
208 | struct sdei_registered_event *reg; | |
209 | ||
210 | lockdep_assert_held(&sdei_events_lock); | |
211 | ||
212 | event = kzalloc(sizeof(*event), GFP_KERNEL); | |
213 | if (!event) | |
214 | return ERR_PTR(-ENOMEM); | |
215 | ||
216 | INIT_LIST_HEAD(&event->list); | |
217 | event->event_num = event_num; | |
218 | ||
219 | err = sdei_api_event_get_info(event_num, SDEI_EVENT_INFO_EV_PRIORITY, | |
220 | &result); | |
221 | if (err) { | |
222 | kfree(event); | |
223 | return ERR_PTR(err); | |
224 | } | |
225 | event->priority = result; | |
226 | ||
227 | err = sdei_api_event_get_info(event_num, SDEI_EVENT_INFO_EV_TYPE, | |
228 | &result); | |
229 | if (err) { | |
230 | kfree(event); | |
231 | return ERR_PTR(err); | |
232 | } | |
233 | event->type = result; | |
234 | ||
235 | if (event->type == SDEI_EVENT_TYPE_SHARED) { | |
236 | reg = kzalloc(sizeof(*reg), GFP_KERNEL); | |
237 | if (!reg) { | |
238 | kfree(event); | |
239 | return ERR_PTR(-ENOMEM); | |
240 | } | |
241 | ||
242 | reg->event_num = event_num; | |
243 | reg->priority = event->priority; | |
244 | ||
245 | reg->callback = cb; | |
246 | reg->callback_arg = cb_arg; | |
247 | event->registered = reg; | |
f92b5462 JM |
248 | } else { |
249 | int cpu; | |
250 | struct sdei_registered_event __percpu *regs; | |
251 | ||
252 | regs = alloc_percpu(struct sdei_registered_event); | |
253 | if (!regs) { | |
254 | kfree(event); | |
255 | return ERR_PTR(-ENOMEM); | |
256 | } | |
257 | ||
258 | for_each_possible_cpu(cpu) { | |
259 | reg = per_cpu_ptr(regs, cpu); | |
260 | ||
261 | reg->event_num = event->event_num; | |
262 | reg->priority = event->priority; | |
263 | reg->callback = cb; | |
264 | reg->callback_arg = cb_arg; | |
265 | } | |
266 | ||
267 | event->private_registered = regs; | |
ad6eb31e JM |
268 | } |
269 | ||
f7d5ef0c LZ |
270 | spin_lock(&sdei_list_lock); |
271 | list_add(&event->list, &sdei_list); | |
272 | spin_unlock(&sdei_list_lock); | |
ad6eb31e JM |
273 | |
274 | return event; | |
275 | } | |
276 | ||
c66d52b1 | 277 | static void sdei_event_destroy_llocked(struct sdei_event *event) |
ad6eb31e JM |
278 | { |
279 | lockdep_assert_held(&sdei_events_lock); | |
c66d52b1 | 280 | lockdep_assert_held(&sdei_list_lock); |
ad6eb31e | 281 | |
ad6eb31e | 282 | list_del(&event->list); |
ad6eb31e JM |
283 | |
284 | if (event->type == SDEI_EVENT_TYPE_SHARED) | |
285 | kfree(event->registered); | |
f92b5462 JM |
286 | else |
287 | free_percpu(event->private_registered); | |
ad6eb31e JM |
288 | |
289 | kfree(event); | |
290 | } | |
291 | ||
c66d52b1 LZ |
292 | static void sdei_event_destroy(struct sdei_event *event) |
293 | { | |
294 | spin_lock(&sdei_list_lock); | |
295 | sdei_event_destroy_llocked(event); | |
296 | spin_unlock(&sdei_list_lock); | |
297 | } | |
298 | ||
ad6eb31e JM |
299 | static int sdei_api_get_version(u64 *version) |
300 | { | |
301 | return invoke_sdei_fn(SDEI_1_0_FN_SDEI_VERSION, 0, 0, 0, 0, 0, version); | |
302 | } | |
303 | ||
304 | int sdei_mask_local_cpu(void) | |
305 | { | |
306 | int err; | |
307 | ||
308 | WARN_ON_ONCE(preemptible()); | |
309 | ||
310 | err = invoke_sdei_fn(SDEI_1_0_FN_SDEI_PE_MASK, 0, 0, 0, 0, 0, NULL); | |
311 | if (err && err != -EIO) { | |
312 | pr_warn_once("failed to mask CPU[%u]: %d\n", | |
313 | smp_processor_id(), err); | |
314 | return err; | |
315 | } | |
316 | ||
317 | return 0; | |
318 | } | |
319 | ||
320 | static void _ipi_mask_cpu(void *ignored) | |
321 | { | |
322 | sdei_mask_local_cpu(); | |
323 | } | |
324 | ||
325 | int sdei_unmask_local_cpu(void) | |
326 | { | |
327 | int err; | |
328 | ||
329 | WARN_ON_ONCE(preemptible()); | |
330 | ||
331 | err = invoke_sdei_fn(SDEI_1_0_FN_SDEI_PE_UNMASK, 0, 0, 0, 0, 0, NULL); | |
332 | if (err && err != -EIO) { | |
333 | pr_warn_once("failed to unmask CPU[%u]: %d\n", | |
334 | smp_processor_id(), err); | |
335 | return err; | |
336 | } | |
337 | ||
338 | return 0; | |
339 | } | |
340 | ||
341 | static void _ipi_unmask_cpu(void *ignored) | |
342 | { | |
343 | sdei_unmask_local_cpu(); | |
344 | } | |
345 | ||
346 | static void _ipi_private_reset(void *ignored) | |
347 | { | |
348 | int err; | |
349 | ||
350 | err = invoke_sdei_fn(SDEI_1_0_FN_SDEI_PRIVATE_RESET, 0, 0, 0, 0, 0, | |
351 | NULL); | |
352 | if (err && err != -EIO) | |
353 | pr_warn_once("failed to reset CPU[%u]: %d\n", | |
354 | smp_processor_id(), err); | |
355 | } | |
356 | ||
357 | static int sdei_api_shared_reset(void) | |
358 | { | |
359 | return invoke_sdei_fn(SDEI_1_0_FN_SDEI_SHARED_RESET, 0, 0, 0, 0, 0, | |
360 | NULL); | |
361 | } | |
362 | ||
363 | static void sdei_mark_interface_broken(void) | |
364 | { | |
365 | pr_err("disabling SDEI firmware interface\n"); | |
366 | on_each_cpu(&_ipi_mask_cpu, NULL, true); | |
367 | sdei_firmware_call = NULL; | |
368 | } | |
369 | ||
370 | static int sdei_platform_reset(void) | |
371 | { | |
372 | int err; | |
373 | ||
374 | on_each_cpu(&_ipi_private_reset, NULL, true); | |
375 | err = sdei_api_shared_reset(); | |
376 | if (err) { | |
377 | pr_err("Failed to reset platform: %d\n", err); | |
378 | sdei_mark_interface_broken(); | |
379 | } | |
380 | ||
381 | return err; | |
382 | } | |
383 | ||
384 | static int sdei_api_event_enable(u32 event_num) | |
385 | { | |
386 | return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_ENABLE, event_num, 0, 0, 0, | |
387 | 0, NULL); | |
388 | } | |
389 | ||
f92b5462 JM |
390 | /* Called directly by the hotplug callbacks */ |
391 | static void _local_event_enable(void *data) | |
392 | { | |
393 | int err; | |
394 | struct sdei_crosscall_args *arg = data; | |
395 | ||
396 | WARN_ON_ONCE(preemptible()); | |
397 | ||
398 | err = sdei_api_event_enable(arg->event->event_num); | |
399 | ||
400 | sdei_cross_call_return(arg, err); | |
401 | } | |
402 | ||
ad6eb31e JM |
403 | int sdei_event_enable(u32 event_num) |
404 | { | |
405 | int err = -EINVAL; | |
406 | struct sdei_event *event; | |
407 | ||
408 | mutex_lock(&sdei_events_lock); | |
409 | event = sdei_event_find(event_num); | |
410 | if (!event) { | |
411 | mutex_unlock(&sdei_events_lock); | |
412 | return -ENOENT; | |
413 | } | |
414 | ||
da351827 | 415 | |
54f529a6 | 416 | cpus_read_lock(); |
ad6eb31e JM |
417 | if (event->type == SDEI_EVENT_TYPE_SHARED) |
418 | err = sdei_api_event_enable(event->event_num); | |
f92b5462 JM |
419 | else |
420 | err = sdei_do_cross_call(_local_event_enable, event); | |
54f529a6 JM |
421 | |
422 | if (!err) { | |
423 | spin_lock(&sdei_list_lock); | |
424 | event->reenable = true; | |
425 | spin_unlock(&sdei_list_lock); | |
426 | } | |
427 | cpus_read_unlock(); | |
ad6eb31e JM |
428 | mutex_unlock(&sdei_events_lock); |
429 | ||
430 | return err; | |
431 | } | |
ad6eb31e JM |
432 | |
433 | static int sdei_api_event_disable(u32 event_num) | |
434 | { | |
435 | return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_DISABLE, event_num, 0, 0, | |
436 | 0, 0, NULL); | |
437 | } | |
438 | ||
f92b5462 JM |
439 | static void _ipi_event_disable(void *data) |
440 | { | |
441 | int err; | |
442 | struct sdei_crosscall_args *arg = data; | |
443 | ||
444 | err = sdei_api_event_disable(arg->event->event_num); | |
445 | ||
446 | sdei_cross_call_return(arg, err); | |
447 | } | |
448 | ||
ad6eb31e JM |
449 | int sdei_event_disable(u32 event_num) |
450 | { | |
451 | int err = -EINVAL; | |
452 | struct sdei_event *event; | |
453 | ||
454 | mutex_lock(&sdei_events_lock); | |
455 | event = sdei_event_find(event_num); | |
456 | if (!event) { | |
457 | mutex_unlock(&sdei_events_lock); | |
458 | return -ENOENT; | |
459 | } | |
460 | ||
da351827 JM |
461 | spin_lock(&sdei_list_lock); |
462 | event->reenable = false; | |
463 | spin_unlock(&sdei_list_lock); | |
464 | ||
ad6eb31e JM |
465 | if (event->type == SDEI_EVENT_TYPE_SHARED) |
466 | err = sdei_api_event_disable(event->event_num); | |
f92b5462 JM |
467 | else |
468 | err = sdei_do_cross_call(_ipi_event_disable, event); | |
ad6eb31e JM |
469 | mutex_unlock(&sdei_events_lock); |
470 | ||
471 | return err; | |
472 | } | |
ad6eb31e JM |
473 | |
474 | static int sdei_api_event_unregister(u32 event_num) | |
475 | { | |
476 | return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_UNREGISTER, event_num, 0, | |
477 | 0, 0, 0, NULL); | |
478 | } | |
479 | ||
f92b5462 JM |
480 | /* Called directly by the hotplug callbacks */ |
481 | static void _local_event_unregister(void *data) | |
482 | { | |
483 | int err; | |
484 | struct sdei_crosscall_args *arg = data; | |
485 | ||
486 | WARN_ON_ONCE(preemptible()); | |
487 | ||
488 | err = sdei_api_event_unregister(arg->event->event_num); | |
489 | ||
490 | sdei_cross_call_return(arg, err); | |
491 | } | |
492 | ||
ad6eb31e JM |
493 | static int _sdei_event_unregister(struct sdei_event *event) |
494 | { | |
495 | lockdep_assert_held(&sdei_events_lock); | |
496 | ||
497 | if (event->type == SDEI_EVENT_TYPE_SHARED) | |
498 | return sdei_api_event_unregister(event->event_num); | |
499 | ||
f92b5462 | 500 | return sdei_do_cross_call(_local_event_unregister, event); |
ad6eb31e JM |
501 | } |
502 | ||
503 | int sdei_event_unregister(u32 event_num) | |
504 | { | |
505 | int err; | |
506 | struct sdei_event *event; | |
507 | ||
508 | WARN_ON(in_nmi()); | |
509 | ||
510 | mutex_lock(&sdei_events_lock); | |
511 | event = sdei_event_find(event_num); | |
512 | do { | |
513 | if (!event) { | |
514 | pr_warn("Event %u not registered\n", event_num); | |
515 | err = -ENOENT; | |
516 | break; | |
517 | } | |
518 | ||
6ded0b61 JM |
519 | spin_lock(&sdei_list_lock); |
520 | event->reregister = false; | |
521 | event->reenable = false; | |
522 | spin_unlock(&sdei_list_lock); | |
523 | ||
ad6eb31e JM |
524 | err = _sdei_event_unregister(event); |
525 | if (err) | |
526 | break; | |
527 | ||
528 | sdei_event_destroy(event); | |
529 | } while (0); | |
530 | mutex_unlock(&sdei_events_lock); | |
531 | ||
532 | return err; | |
533 | } | |
ad6eb31e | 534 | |
da351827 JM |
535 | /* |
536 | * unregister events, but don't destroy them as they are re-registered by | |
537 | * sdei_reregister_shared(). | |
538 | */ | |
539 | static int sdei_unregister_shared(void) | |
540 | { | |
541 | int err = 0; | |
542 | struct sdei_event *event; | |
543 | ||
544 | mutex_lock(&sdei_events_lock); | |
545 | spin_lock(&sdei_list_lock); | |
546 | list_for_each_entry(event, &sdei_list, list) { | |
547 | if (event->type != SDEI_EVENT_TYPE_SHARED) | |
548 | continue; | |
549 | ||
550 | err = _sdei_event_unregister(event); | |
551 | if (err) | |
552 | break; | |
553 | } | |
554 | spin_unlock(&sdei_list_lock); | |
555 | mutex_unlock(&sdei_events_lock); | |
556 | ||
557 | return err; | |
558 | } | |
559 | ||
ad6eb31e JM |
560 | static int sdei_api_event_register(u32 event_num, unsigned long entry_point, |
561 | void *arg, u64 flags, u64 affinity) | |
562 | { | |
563 | return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_REGISTER, event_num, | |
564 | (unsigned long)entry_point, (unsigned long)arg, | |
565 | flags, affinity, NULL); | |
566 | } | |
567 | ||
f92b5462 JM |
568 | /* Called directly by the hotplug callbacks */ |
569 | static void _local_event_register(void *data) | |
570 | { | |
571 | int err; | |
572 | struct sdei_registered_event *reg; | |
573 | struct sdei_crosscall_args *arg = data; | |
574 | ||
575 | WARN_ON(preemptible()); | |
576 | ||
577 | reg = per_cpu_ptr(arg->event->private_registered, smp_processor_id()); | |
578 | err = sdei_api_event_register(arg->event->event_num, sdei_entry_point, | |
579 | reg, 0, 0); | |
580 | ||
581 | sdei_cross_call_return(arg, err); | |
582 | } | |
583 | ||
ad6eb31e JM |
584 | static int _sdei_event_register(struct sdei_event *event) |
585 | { | |
f92b5462 JM |
586 | int err; |
587 | ||
ad6eb31e JM |
588 | lockdep_assert_held(&sdei_events_lock); |
589 | ||
590 | if (event->type == SDEI_EVENT_TYPE_SHARED) | |
591 | return sdei_api_event_register(event->event_num, | |
592 | sdei_entry_point, | |
593 | event->registered, | |
594 | SDEI_EVENT_REGISTER_RM_ANY, 0); | |
595 | ||
f92b5462 | 596 | err = sdei_do_cross_call(_local_event_register, event); |
6ded0b61 | 597 | if (err) |
f92b5462 | 598 | sdei_do_cross_call(_local_event_unregister, event); |
f92b5462 JM |
599 | |
600 | return err; | |
ad6eb31e JM |
601 | } |
602 | ||
603 | int sdei_event_register(u32 event_num, sdei_event_callback *cb, void *arg) | |
604 | { | |
605 | int err; | |
606 | struct sdei_event *event; | |
607 | ||
608 | WARN_ON(in_nmi()); | |
609 | ||
610 | mutex_lock(&sdei_events_lock); | |
611 | do { | |
612 | if (sdei_event_find(event_num)) { | |
613 | pr_warn("Event %u already registered\n", event_num); | |
614 | err = -EBUSY; | |
615 | break; | |
616 | } | |
617 | ||
618 | event = sdei_event_create(event_num, cb, arg); | |
619 | if (IS_ERR(event)) { | |
620 | err = PTR_ERR(event); | |
621 | pr_warn("Failed to create event %u: %d\n", event_num, | |
622 | err); | |
623 | break; | |
624 | } | |
625 | ||
54f529a6 | 626 | cpus_read_lock(); |
ad6eb31e JM |
627 | err = _sdei_event_register(event); |
628 | if (err) { | |
629 | sdei_event_destroy(event); | |
630 | pr_warn("Failed to register event %u: %d\n", event_num, | |
631 | err); | |
54f529a6 JM |
632 | } else { |
633 | spin_lock(&sdei_list_lock); | |
634 | event->reregister = true; | |
635 | spin_unlock(&sdei_list_lock); | |
ad6eb31e | 636 | } |
54f529a6 | 637 | cpus_read_unlock(); |
ad6eb31e JM |
638 | } while (0); |
639 | mutex_unlock(&sdei_events_lock); | |
640 | ||
641 | return err; | |
642 | } | |
ad6eb31e | 643 | |
c66d52b1 | 644 | static int sdei_reregister_event_llocked(struct sdei_event *event) |
da351827 JM |
645 | { |
646 | int err; | |
647 | ||
648 | lockdep_assert_held(&sdei_events_lock); | |
c66d52b1 | 649 | lockdep_assert_held(&sdei_list_lock); |
da351827 JM |
650 | |
651 | err = _sdei_event_register(event); | |
652 | if (err) { | |
653 | pr_err("Failed to re-register event %u\n", event->event_num); | |
c66d52b1 | 654 | sdei_event_destroy_llocked(event); |
da351827 JM |
655 | return err; |
656 | } | |
657 | ||
658 | if (event->reenable) { | |
659 | if (event->type == SDEI_EVENT_TYPE_SHARED) | |
660 | err = sdei_api_event_enable(event->event_num); | |
f92b5462 JM |
661 | else |
662 | err = sdei_do_cross_call(_local_event_enable, event); | |
da351827 JM |
663 | } |
664 | ||
665 | if (err) | |
666 | pr_err("Failed to re-enable event %u\n", event->event_num); | |
667 | ||
668 | return err; | |
669 | } | |
670 | ||
671 | static int sdei_reregister_shared(void) | |
672 | { | |
673 | int err = 0; | |
674 | struct sdei_event *event; | |
675 | ||
676 | mutex_lock(&sdei_events_lock); | |
677 | spin_lock(&sdei_list_lock); | |
678 | list_for_each_entry(event, &sdei_list, list) { | |
679 | if (event->type != SDEI_EVENT_TYPE_SHARED) | |
680 | continue; | |
681 | ||
682 | if (event->reregister) { | |
c66d52b1 | 683 | err = sdei_reregister_event_llocked(event); |
da351827 JM |
684 | if (err) |
685 | break; | |
686 | } | |
687 | } | |
688 | spin_unlock(&sdei_list_lock); | |
689 | mutex_unlock(&sdei_events_lock); | |
690 | ||
691 | return err; | |
692 | } | |
693 | ||
f92b5462 JM |
694 | static int sdei_cpuhp_down(unsigned int cpu) |
695 | { | |
696 | struct sdei_event *event; | |
697 | struct sdei_crosscall_args arg; | |
698 | ||
699 | /* un-register private events */ | |
700 | spin_lock(&sdei_list_lock); | |
701 | list_for_each_entry(event, &sdei_list, list) { | |
702 | if (event->type == SDEI_EVENT_TYPE_SHARED) | |
703 | continue; | |
704 | ||
705 | CROSSCALL_INIT(arg, event); | |
706 | /* call the cross-call function locally... */ | |
707 | _local_event_unregister(&arg); | |
708 | if (arg.first_error) | |
709 | pr_err("Failed to unregister event %u: %d\n", | |
710 | event->event_num, arg.first_error); | |
711 | } | |
712 | spin_unlock(&sdei_list_lock); | |
713 | ||
714 | return sdei_mask_local_cpu(); | |
715 | } | |
716 | ||
717 | static int sdei_cpuhp_up(unsigned int cpu) | |
718 | { | |
719 | struct sdei_event *event; | |
720 | struct sdei_crosscall_args arg; | |
721 | ||
722 | /* re-register/enable private events */ | |
723 | spin_lock(&sdei_list_lock); | |
724 | list_for_each_entry(event, &sdei_list, list) { | |
725 | if (event->type == SDEI_EVENT_TYPE_SHARED) | |
726 | continue; | |
727 | ||
728 | if (event->reregister) { | |
729 | CROSSCALL_INIT(arg, event); | |
730 | /* call the cross-call function locally... */ | |
731 | _local_event_register(&arg); | |
732 | if (arg.first_error) | |
733 | pr_err("Failed to re-register event %u: %d\n", | |
734 | event->event_num, arg.first_error); | |
735 | } | |
736 | ||
737 | if (event->reenable) { | |
738 | CROSSCALL_INIT(arg, event); | |
739 | _local_event_enable(&arg); | |
740 | if (arg.first_error) | |
741 | pr_err("Failed to re-enable event %u: %d\n", | |
742 | event->event_num, arg.first_error); | |
743 | } | |
744 | } | |
745 | spin_unlock(&sdei_list_lock); | |
746 | ||
747 | return sdei_unmask_local_cpu(); | |
748 | } | |
749 | ||
da351827 JM |
750 | /* When entering idle, mask/unmask events for this cpu */ |
751 | static int sdei_pm_notifier(struct notifier_block *nb, unsigned long action, | |
752 | void *data) | |
753 | { | |
754 | int rv; | |
755 | ||
756 | switch (action) { | |
757 | case CPU_PM_ENTER: | |
758 | rv = sdei_mask_local_cpu(); | |
759 | break; | |
760 | case CPU_PM_EXIT: | |
761 | case CPU_PM_ENTER_FAILED: | |
762 | rv = sdei_unmask_local_cpu(); | |
763 | break; | |
764 | default: | |
765 | return NOTIFY_DONE; | |
766 | } | |
767 | ||
768 | if (rv) | |
769 | return notifier_from_errno(rv); | |
770 | ||
771 | return NOTIFY_OK; | |
772 | } | |
773 | ||
774 | static struct notifier_block sdei_pm_nb = { | |
775 | .notifier_call = sdei_pm_notifier, | |
776 | }; | |
777 | ||
778 | static int sdei_device_suspend(struct device *dev) | |
779 | { | |
780 | on_each_cpu(_ipi_mask_cpu, NULL, true); | |
781 | ||
782 | return 0; | |
783 | } | |
784 | ||
785 | static int sdei_device_resume(struct device *dev) | |
786 | { | |
787 | on_each_cpu(_ipi_unmask_cpu, NULL, true); | |
788 | ||
789 | return 0; | |
790 | } | |
791 | ||
792 | /* | |
793 | * We need all events to be reregistered when we resume from hibernate. | |
794 | * | |
795 | * The sequence is freeze->thaw. Reboot. freeze->restore. We unregister | |
796 | * events during freeze, then re-register and re-enable them during thaw | |
797 | * and restore. | |
798 | */ | |
799 | static int sdei_device_freeze(struct device *dev) | |
800 | { | |
801 | int err; | |
802 | ||
f92b5462 | 803 | /* unregister private events */ |
da351827 JM |
804 | cpuhp_remove_state(CPUHP_AP_ARM_SDEI_STARTING); |
805 | ||
806 | err = sdei_unregister_shared(); | |
807 | if (err) | |
808 | return err; | |
809 | ||
810 | return 0; | |
811 | } | |
812 | ||
813 | static int sdei_device_thaw(struct device *dev) | |
814 | { | |
815 | int err; | |
816 | ||
817 | /* re-register shared events */ | |
818 | err = sdei_reregister_shared(); | |
819 | if (err) { | |
820 | pr_warn("Failed to re-register shared events...\n"); | |
821 | sdei_mark_interface_broken(); | |
822 | return err; | |
823 | } | |
824 | ||
825 | err = cpuhp_setup_state(CPUHP_AP_ARM_SDEI_STARTING, "SDEI", | |
826 | &sdei_cpuhp_up, &sdei_cpuhp_down); | |
827 | if (err) | |
828 | pr_warn("Failed to re-register CPU hotplug notifier...\n"); | |
829 | ||
830 | return err; | |
831 | } | |
832 | ||
833 | static int sdei_device_restore(struct device *dev) | |
834 | { | |
835 | int err; | |
836 | ||
837 | err = sdei_platform_reset(); | |
838 | if (err) | |
839 | return err; | |
840 | ||
841 | return sdei_device_thaw(dev); | |
842 | } | |
843 | ||
844 | static const struct dev_pm_ops sdei_pm_ops = { | |
845 | .suspend = sdei_device_suspend, | |
846 | .resume = sdei_device_resume, | |
847 | .freeze = sdei_device_freeze, | |
848 | .thaw = sdei_device_thaw, | |
849 | .restore = sdei_device_restore, | |
850 | }; | |
851 | ||
852 | /* | |
853 | * Mask all CPUs and unregister all events on panic, reboot or kexec. | |
854 | */ | |
855 | static int sdei_reboot_notifier(struct notifier_block *nb, unsigned long action, | |
856 | void *data) | |
857 | { | |
858 | /* | |
859 | * We are going to reset the interface, after this there is no point | |
860 | * doing work when we take CPUs offline. | |
861 | */ | |
862 | cpuhp_remove_state(CPUHP_AP_ARM_SDEI_STARTING); | |
863 | ||
864 | sdei_platform_reset(); | |
865 | ||
866 | return NOTIFY_OK; | |
867 | } | |
868 | ||
869 | static struct notifier_block sdei_reboot_nb = { | |
870 | .notifier_call = sdei_reboot_notifier, | |
871 | }; | |
872 | ||
ad6eb31e JM |
873 | static void sdei_smccc_smc(unsigned long function_id, |
874 | unsigned long arg0, unsigned long arg1, | |
875 | unsigned long arg2, unsigned long arg3, | |
876 | unsigned long arg4, struct arm_smccc_res *res) | |
877 | { | |
878 | arm_smccc_smc(function_id, arg0, arg1, arg2, arg3, arg4, 0, 0, res); | |
879 | } | |
2f1d4e24 | 880 | NOKPROBE_SYMBOL(sdei_smccc_smc); |
ad6eb31e JM |
881 | |
882 | static void sdei_smccc_hvc(unsigned long function_id, | |
883 | unsigned long arg0, unsigned long arg1, | |
884 | unsigned long arg2, unsigned long arg3, | |
885 | unsigned long arg4, struct arm_smccc_res *res) | |
886 | { | |
887 | arm_smccc_hvc(function_id, arg0, arg1, arg2, arg3, arg4, 0, 0, res); | |
888 | } | |
2f1d4e24 | 889 | NOKPROBE_SYMBOL(sdei_smccc_hvc); |
ad6eb31e | 890 | |
f96935d3 JM |
891 | int sdei_register_ghes(struct ghes *ghes, sdei_event_callback *normal_cb, |
892 | sdei_event_callback *critical_cb) | |
893 | { | |
894 | int err; | |
895 | u64 result; | |
896 | u32 event_num; | |
897 | sdei_event_callback *cb; | |
898 | ||
899 | if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES)) | |
900 | return -EOPNOTSUPP; | |
901 | ||
902 | event_num = ghes->generic->notify.vector; | |
903 | if (event_num == 0) { | |
904 | /* | |
905 | * Event 0 is reserved by the specification for | |
906 | * SDEI_EVENT_SIGNAL. | |
907 | */ | |
908 | return -EINVAL; | |
909 | } | |
910 | ||
911 | err = sdei_api_event_get_info(event_num, SDEI_EVENT_INFO_EV_PRIORITY, | |
912 | &result); | |
913 | if (err) | |
914 | return err; | |
915 | ||
916 | if (result == SDEI_EVENT_PRIORITY_CRITICAL) | |
917 | cb = critical_cb; | |
918 | else | |
919 | cb = normal_cb; | |
920 | ||
921 | err = sdei_event_register(event_num, cb, ghes); | |
922 | if (!err) | |
923 | err = sdei_event_enable(event_num); | |
924 | ||
925 | return err; | |
926 | } | |
927 | ||
928 | int sdei_unregister_ghes(struct ghes *ghes) | |
929 | { | |
930 | int i; | |
931 | int err; | |
932 | u32 event_num = ghes->generic->notify.vector; | |
933 | ||
934 | might_sleep(); | |
935 | ||
936 | if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES)) | |
937 | return -EOPNOTSUPP; | |
938 | ||
939 | /* | |
940 | * The event may be running on another CPU. Disable it | |
941 | * to stop new events, then try to unregister a few times. | |
942 | */ | |
943 | err = sdei_event_disable(event_num); | |
944 | if (err) | |
945 | return err; | |
946 | ||
947 | for (i = 0; i < 3; i++) { | |
948 | err = sdei_event_unregister(event_num); | |
949 | if (err != -EINPROGRESS) | |
950 | break; | |
951 | ||
952 | schedule(); | |
953 | } | |
954 | ||
955 | return err; | |
956 | } | |
957 | ||
ad6eb31e JM |
958 | static int sdei_get_conduit(struct platform_device *pdev) |
959 | { | |
960 | const char *method; | |
961 | struct device_node *np = pdev->dev.of_node; | |
962 | ||
963 | sdei_firmware_call = NULL; | |
964 | if (np) { | |
965 | if (of_property_read_string(np, "method", &method)) { | |
966 | pr_warn("missing \"method\" property\n"); | |
e6ea4651 | 967 | return SMCCC_CONDUIT_NONE; |
ad6eb31e JM |
968 | } |
969 | ||
970 | if (!strcmp("hvc", method)) { | |
971 | sdei_firmware_call = &sdei_smccc_hvc; | |
e6ea4651 | 972 | return SMCCC_CONDUIT_HVC; |
ad6eb31e JM |
973 | } else if (!strcmp("smc", method)) { |
974 | sdei_firmware_call = &sdei_smccc_smc; | |
e6ea4651 | 975 | return SMCCC_CONDUIT_SMC; |
ad6eb31e JM |
976 | } |
977 | ||
978 | pr_warn("invalid \"method\" property: %s\n", method); | |
677a60bd JM |
979 | } else if (IS_ENABLED(CONFIG_ACPI) && !acpi_disabled) { |
980 | if (acpi_psci_use_hvc()) { | |
981 | sdei_firmware_call = &sdei_smccc_hvc; | |
e6ea4651 | 982 | return SMCCC_CONDUIT_HVC; |
677a60bd JM |
983 | } else { |
984 | sdei_firmware_call = &sdei_smccc_smc; | |
e6ea4651 | 985 | return SMCCC_CONDUIT_SMC; |
677a60bd | 986 | } |
ad6eb31e JM |
987 | } |
988 | ||
e6ea4651 | 989 | return SMCCC_CONDUIT_NONE; |
ad6eb31e JM |
990 | } |
991 | ||
992 | static int sdei_probe(struct platform_device *pdev) | |
993 | { | |
994 | int err; | |
995 | u64 ver = 0; | |
996 | int conduit; | |
997 | ||
998 | conduit = sdei_get_conduit(pdev); | |
999 | if (!sdei_firmware_call) | |
1000 | return 0; | |
1001 | ||
1002 | err = sdei_api_get_version(&ver); | |
1003 | if (err == -EOPNOTSUPP) | |
1004 | pr_err("advertised but not implemented in platform firmware\n"); | |
1005 | if (err) { | |
1006 | pr_err("Failed to get SDEI version: %d\n", err); | |
1007 | sdei_mark_interface_broken(); | |
1008 | return err; | |
1009 | } | |
1010 | ||
1011 | pr_info("SDEIv%d.%d (0x%x) detected in firmware.\n", | |
1012 | (int)SDEI_VERSION_MAJOR(ver), (int)SDEI_VERSION_MINOR(ver), | |
1013 | (int)SDEI_VERSION_VENDOR(ver)); | |
1014 | ||
1015 | if (SDEI_VERSION_MAJOR(ver) != 1) { | |
1016 | pr_warn("Conflicting SDEI version detected.\n"); | |
1017 | sdei_mark_interface_broken(); | |
1018 | return -EINVAL; | |
1019 | } | |
1020 | ||
1021 | err = sdei_platform_reset(); | |
1022 | if (err) | |
1023 | return err; | |
1024 | ||
1025 | sdei_entry_point = sdei_arch_get_entry_point(conduit); | |
1026 | if (!sdei_entry_point) { | |
1027 | /* Not supported due to hardware or boot configuration */ | |
1028 | sdei_mark_interface_broken(); | |
1029 | return 0; | |
1030 | } | |
1031 | ||
da351827 JM |
1032 | err = cpu_pm_register_notifier(&sdei_pm_nb); |
1033 | if (err) { | |
1034 | pr_warn("Failed to register CPU PM notifier...\n"); | |
1035 | goto error; | |
1036 | } | |
1037 | ||
1038 | err = register_reboot_notifier(&sdei_reboot_nb); | |
1039 | if (err) { | |
1040 | pr_warn("Failed to register reboot notifier...\n"); | |
1041 | goto remove_cpupm; | |
1042 | } | |
1043 | ||
1044 | err = cpuhp_setup_state(CPUHP_AP_ARM_SDEI_STARTING, "SDEI", | |
1045 | &sdei_cpuhp_up, &sdei_cpuhp_down); | |
1046 | if (err) { | |
1047 | pr_warn("Failed to register CPU hotplug notifier...\n"); | |
1048 | goto remove_reboot; | |
1049 | } | |
ad6eb31e JM |
1050 | |
1051 | return 0; | |
da351827 JM |
1052 | |
1053 | remove_reboot: | |
1054 | unregister_reboot_notifier(&sdei_reboot_nb); | |
1055 | ||
1056 | remove_cpupm: | |
1057 | cpu_pm_unregister_notifier(&sdei_pm_nb); | |
1058 | ||
1059 | error: | |
1060 | sdei_mark_interface_broken(); | |
1061 | return err; | |
ad6eb31e JM |
1062 | } |
1063 | ||
1064 | static const struct of_device_id sdei_of_match[] = { | |
1065 | { .compatible = "arm,sdei-1.0" }, | |
1066 | {} | |
1067 | }; | |
1068 | ||
1069 | static struct platform_driver sdei_driver = { | |
1070 | .driver = { | |
1071 | .name = "sdei", | |
da351827 | 1072 | .pm = &sdei_pm_ops, |
ad6eb31e JM |
1073 | .of_match_table = sdei_of_match, |
1074 | }, | |
1075 | .probe = sdei_probe, | |
1076 | }; | |
1077 | ||
677a60bd JM |
1078 | static bool __init sdei_present_acpi(void) |
1079 | { | |
1080 | acpi_status status; | |
677a60bd JM |
1081 | struct acpi_table_header *sdei_table_header; |
1082 | ||
1083 | if (acpi_disabled) | |
1084 | return false; | |
1085 | ||
1086 | status = acpi_get_table(ACPI_SIG_SDEI, 0, &sdei_table_header); | |
1087 | if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) { | |
1088 | const char *msg = acpi_format_exception(status); | |
1089 | ||
1090 | pr_info("Failed to get ACPI:SDEI table, %s\n", msg); | |
1091 | } | |
1092 | if (ACPI_FAILURE(status)) | |
1093 | return false; | |
1094 | ||
70e6352a HG |
1095 | acpi_put_table(sdei_table_header); |
1096 | ||
677a60bd JM |
1097 | return true; |
1098 | } | |
1099 | ||
ad6eb31e JM |
1100 | static int __init sdei_init(void) |
1101 | { | |
caf2cd61 | 1102 | int ret = platform_driver_register(&sdei_driver); |
ad6eb31e | 1103 | |
caf2cd61 SH |
1104 | if (!ret && sdei_present_acpi()) { |
1105 | struct platform_device *pdev; | |
1106 | ||
1107 | pdev = platform_device_register_simple(sdei_driver.driver.name, | |
1108 | 0, NULL, 0); | |
1109 | if (IS_ERR(pdev)) | |
1110 | pr_info("Failed to register ACPI:SDEI platform device %ld\n", | |
1111 | PTR_ERR(pdev)); | |
1112 | } | |
1113 | ||
1114 | return ret; | |
ad6eb31e JM |
1115 | } |
1116 | ||
677a60bd JM |
1117 | /* |
1118 | * On an ACPI system SDEI needs to be ready before HEST:GHES tries to register | |
1119 | * its events. ACPI is initialised from a subsys_initcall(), GHES is initialised | |
1120 | * by device_initcall(). We want to be called in the middle. | |
1121 | */ | |
ad6eb31e JM |
1122 | subsys_initcall_sync(sdei_init); |
1123 | ||
1124 | int sdei_event_handler(struct pt_regs *regs, | |
1125 | struct sdei_registered_event *arg) | |
1126 | { | |
1127 | int err; | |
1128 | mm_segment_t orig_addr_limit; | |
1129 | u32 event_num = arg->event_num; | |
1130 | ||
472de63b JM |
1131 | /* |
1132 | * Save restore 'fs'. | |
1133 | * The architecture's entry code save/restores 'fs' when taking an | |
1134 | * exception from the kernel. This ensures addr_limit isn't inherited | |
1135 | * if you interrupted something that allowed the uaccess routines to | |
1136 | * access kernel memory. | |
1137 | * Do the same here because this doesn't come via the same entry code. | |
1138 | */ | |
ad6eb31e JM |
1139 | orig_addr_limit = get_fs(); |
1140 | set_fs(USER_DS); | |
1141 | ||
1142 | err = arg->callback(event_num, regs, arg->callback_arg); | |
1143 | if (err) | |
1144 | pr_err_ratelimited("event %u on CPU %u failed with error: %d\n", | |
1145 | event_num, smp_processor_id(), err); | |
1146 | ||
1147 | set_fs(orig_addr_limit); | |
1148 | ||
1149 | return err; | |
1150 | } | |
1151 | NOKPROBE_SYMBOL(sdei_event_handler); |