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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 | ||
5 | #include <linux/acpi.h> | |
6 | #include <linux/arm_sdei.h> | |
7 | #include <linux/arm-smccc.h> | |
f92b5462 | 8 | #include <linux/atomic.h> |
ad6eb31e JM |
9 | #include <linux/bitops.h> |
10 | #include <linux/compiler.h> | |
da351827 | 11 | #include <linux/cpuhotplug.h> |
f92b5462 | 12 | #include <linux/cpu.h> |
da351827 | 13 | #include <linux/cpu_pm.h> |
ad6eb31e JM |
14 | #include <linux/errno.h> |
15 | #include <linux/hardirq.h> | |
16 | #include <linux/kernel.h> | |
17 | #include <linux/kprobes.h> | |
18 | #include <linux/kvm_host.h> | |
19 | #include <linux/list.h> | |
20 | #include <linux/mutex.h> | |
da351827 | 21 | #include <linux/notifier.h> |
ad6eb31e JM |
22 | #include <linux/of.h> |
23 | #include <linux/of_platform.h> | |
24 | #include <linux/percpu.h> | |
25 | #include <linux/platform_device.h> | |
da351827 | 26 | #include <linux/pm.h> |
ad6eb31e JM |
27 | #include <linux/ptrace.h> |
28 | #include <linux/preempt.h> | |
da351827 | 29 | #include <linux/reboot.h> |
ad6eb31e JM |
30 | #include <linux/slab.h> |
31 | #include <linux/smp.h> | |
32 | #include <linux/spinlock.h> | |
33 | #include <linux/uaccess.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 | struct sdei_event { | |
da351827 | 47 | /* These three are protected by the sdei_list_lock */ |
ad6eb31e | 48 | struct list_head list; |
da351827 JM |
49 | bool reregister; |
50 | bool reenable; | |
51 | ||
ad6eb31e JM |
52 | u32 event_num; |
53 | u8 type; | |
54 | u8 priority; | |
55 | ||
56 | /* This pointer is handed to firmware as the event argument. */ | |
f92b5462 JM |
57 | union { |
58 | /* Shared events */ | |
59 | struct sdei_registered_event *registered; | |
60 | ||
61 | /* CPU private events */ | |
62 | struct sdei_registered_event __percpu *private_registered; | |
63 | }; | |
ad6eb31e JM |
64 | }; |
65 | ||
66 | /* Take the mutex for any API call or modification. Take the mutex first. */ | |
67 | static DEFINE_MUTEX(sdei_events_lock); | |
68 | ||
69 | /* and then hold this when modifying the list */ | |
70 | static DEFINE_SPINLOCK(sdei_list_lock); | |
71 | static LIST_HEAD(sdei_list); | |
72 | ||
f92b5462 JM |
73 | /* Private events are registered/enabled via IPI passing one of these */ |
74 | struct sdei_crosscall_args { | |
75 | struct sdei_event *event; | |
76 | atomic_t errors; | |
77 | int first_error; | |
78 | }; | |
79 | ||
80 | #define CROSSCALL_INIT(arg, event) (arg.event = event, \ | |
81 | arg.first_error = 0, \ | |
82 | atomic_set(&arg.errors, 0)) | |
83 | ||
84 | static inline int sdei_do_cross_call(void *fn, struct sdei_event * event) | |
85 | { | |
86 | struct sdei_crosscall_args arg; | |
87 | ||
88 | CROSSCALL_INIT(arg, event); | |
89 | on_each_cpu(fn, &arg, true); | |
90 | ||
91 | return arg.first_error; | |
92 | } | |
93 | ||
94 | static inline void | |
95 | sdei_cross_call_return(struct sdei_crosscall_args *arg, int err) | |
96 | { | |
97 | if (err && (atomic_inc_return(&arg->errors) == 1)) | |
98 | arg->first_error = err; | |
99 | } | |
100 | ||
ad6eb31e JM |
101 | static int sdei_to_linux_errno(unsigned long sdei_err) |
102 | { | |
103 | switch (sdei_err) { | |
104 | case SDEI_NOT_SUPPORTED: | |
105 | return -EOPNOTSUPP; | |
106 | case SDEI_INVALID_PARAMETERS: | |
107 | return -EINVAL; | |
108 | case SDEI_DENIED: | |
109 | return -EPERM; | |
110 | case SDEI_PENDING: | |
111 | return -EINPROGRESS; | |
112 | case SDEI_OUT_OF_RESOURCE: | |
113 | return -ENOMEM; | |
114 | } | |
115 | ||
116 | /* Not an error value ... */ | |
117 | return sdei_err; | |
118 | } | |
119 | ||
120 | /* | |
121 | * If x0 is any of these values, then the call failed, use sdei_to_linux_errno() | |
122 | * to translate. | |
123 | */ | |
124 | static int sdei_is_err(struct arm_smccc_res *res) | |
125 | { | |
126 | switch (res->a0) { | |
127 | case SDEI_NOT_SUPPORTED: | |
128 | case SDEI_INVALID_PARAMETERS: | |
129 | case SDEI_DENIED: | |
130 | case SDEI_PENDING: | |
131 | case SDEI_OUT_OF_RESOURCE: | |
132 | return true; | |
133 | } | |
134 | ||
135 | return false; | |
136 | } | |
137 | ||
138 | static int invoke_sdei_fn(unsigned long function_id, unsigned long arg0, | |
139 | unsigned long arg1, unsigned long arg2, | |
140 | unsigned long arg3, unsigned long arg4, | |
141 | u64 *result) | |
142 | { | |
143 | int err = 0; | |
144 | struct arm_smccc_res res; | |
145 | ||
146 | if (sdei_firmware_call) { | |
147 | sdei_firmware_call(function_id, arg0, arg1, arg2, arg3, arg4, | |
148 | &res); | |
149 | if (sdei_is_err(&res)) | |
150 | err = sdei_to_linux_errno(res.a0); | |
151 | } else { | |
152 | /* | |
153 | * !sdei_firmware_call means we failed to probe or called | |
154 | * sdei_mark_interface_broken(). -EIO is not an error returned | |
155 | * by sdei_to_linux_errno() and is used to suppress messages | |
156 | * from this driver. | |
157 | */ | |
158 | err = -EIO; | |
159 | res.a0 = SDEI_NOT_SUPPORTED; | |
160 | } | |
161 | ||
162 | if (result) | |
163 | *result = res.a0; | |
164 | ||
165 | return err; | |
166 | } | |
167 | ||
168 | static struct sdei_event *sdei_event_find(u32 event_num) | |
169 | { | |
170 | struct sdei_event *e, *found = NULL; | |
171 | ||
172 | lockdep_assert_held(&sdei_events_lock); | |
173 | ||
174 | spin_lock(&sdei_list_lock); | |
175 | list_for_each_entry(e, &sdei_list, list) { | |
176 | if (e->event_num == event_num) { | |
177 | found = e; | |
178 | break; | |
179 | } | |
180 | } | |
181 | spin_unlock(&sdei_list_lock); | |
182 | ||
183 | return found; | |
184 | } | |
185 | ||
186 | int sdei_api_event_context(u32 query, u64 *result) | |
187 | { | |
188 | return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_CONTEXT, query, 0, 0, 0, 0, | |
189 | result); | |
190 | } | |
191 | NOKPROBE_SYMBOL(sdei_api_event_context); | |
192 | ||
193 | static int sdei_api_event_get_info(u32 event, u32 info, u64 *result) | |
194 | { | |
195 | return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_GET_INFO, event, info, 0, | |
196 | 0, 0, result); | |
197 | } | |
198 | ||
199 | static struct sdei_event *sdei_event_create(u32 event_num, | |
200 | sdei_event_callback *cb, | |
201 | void *cb_arg) | |
202 | { | |
203 | int err; | |
204 | u64 result; | |
205 | struct sdei_event *event; | |
206 | struct sdei_registered_event *reg; | |
207 | ||
208 | lockdep_assert_held(&sdei_events_lock); | |
209 | ||
210 | event = kzalloc(sizeof(*event), GFP_KERNEL); | |
211 | if (!event) | |
212 | return ERR_PTR(-ENOMEM); | |
213 | ||
214 | INIT_LIST_HEAD(&event->list); | |
215 | event->event_num = event_num; | |
216 | ||
217 | err = sdei_api_event_get_info(event_num, SDEI_EVENT_INFO_EV_PRIORITY, | |
218 | &result); | |
219 | if (err) { | |
220 | kfree(event); | |
221 | return ERR_PTR(err); | |
222 | } | |
223 | event->priority = result; | |
224 | ||
225 | err = sdei_api_event_get_info(event_num, SDEI_EVENT_INFO_EV_TYPE, | |
226 | &result); | |
227 | if (err) { | |
228 | kfree(event); | |
229 | return ERR_PTR(err); | |
230 | } | |
231 | event->type = result; | |
232 | ||
233 | if (event->type == SDEI_EVENT_TYPE_SHARED) { | |
234 | reg = kzalloc(sizeof(*reg), GFP_KERNEL); | |
235 | if (!reg) { | |
236 | kfree(event); | |
237 | return ERR_PTR(-ENOMEM); | |
238 | } | |
239 | ||
240 | reg->event_num = event_num; | |
241 | reg->priority = event->priority; | |
242 | ||
243 | reg->callback = cb; | |
244 | reg->callback_arg = cb_arg; | |
245 | event->registered = reg; | |
f92b5462 JM |
246 | } else { |
247 | int cpu; | |
248 | struct sdei_registered_event __percpu *regs; | |
249 | ||
250 | regs = alloc_percpu(struct sdei_registered_event); | |
251 | if (!regs) { | |
252 | kfree(event); | |
253 | return ERR_PTR(-ENOMEM); | |
254 | } | |
255 | ||
256 | for_each_possible_cpu(cpu) { | |
257 | reg = per_cpu_ptr(regs, cpu); | |
258 | ||
259 | reg->event_num = event->event_num; | |
260 | reg->priority = event->priority; | |
261 | reg->callback = cb; | |
262 | reg->callback_arg = cb_arg; | |
263 | } | |
264 | ||
265 | event->private_registered = regs; | |
ad6eb31e JM |
266 | } |
267 | ||
268 | if (sdei_event_find(event_num)) { | |
269 | kfree(event->registered); | |
270 | kfree(event); | |
271 | event = ERR_PTR(-EBUSY); | |
272 | } else { | |
273 | spin_lock(&sdei_list_lock); | |
274 | list_add(&event->list, &sdei_list); | |
275 | spin_unlock(&sdei_list_lock); | |
276 | } | |
277 | ||
278 | return event; | |
279 | } | |
280 | ||
281 | static void sdei_event_destroy(struct sdei_event *event) | |
282 | { | |
283 | lockdep_assert_held(&sdei_events_lock); | |
284 | ||
285 | spin_lock(&sdei_list_lock); | |
286 | list_del(&event->list); | |
287 | spin_unlock(&sdei_list_lock); | |
288 | ||
289 | if (event->type == SDEI_EVENT_TYPE_SHARED) | |
290 | kfree(event->registered); | |
f92b5462 JM |
291 | else |
292 | free_percpu(event->private_registered); | |
ad6eb31e JM |
293 | |
294 | kfree(event); | |
295 | } | |
296 | ||
297 | static int sdei_api_get_version(u64 *version) | |
298 | { | |
299 | return invoke_sdei_fn(SDEI_1_0_FN_SDEI_VERSION, 0, 0, 0, 0, 0, version); | |
300 | } | |
301 | ||
302 | int sdei_mask_local_cpu(void) | |
303 | { | |
304 | int err; | |
305 | ||
306 | WARN_ON_ONCE(preemptible()); | |
307 | ||
308 | err = invoke_sdei_fn(SDEI_1_0_FN_SDEI_PE_MASK, 0, 0, 0, 0, 0, NULL); | |
309 | if (err && err != -EIO) { | |
310 | pr_warn_once("failed to mask CPU[%u]: %d\n", | |
311 | smp_processor_id(), err); | |
312 | return err; | |
313 | } | |
314 | ||
315 | return 0; | |
316 | } | |
317 | ||
318 | static void _ipi_mask_cpu(void *ignored) | |
319 | { | |
320 | sdei_mask_local_cpu(); | |
321 | } | |
322 | ||
323 | int sdei_unmask_local_cpu(void) | |
324 | { | |
325 | int err; | |
326 | ||
327 | WARN_ON_ONCE(preemptible()); | |
328 | ||
329 | err = invoke_sdei_fn(SDEI_1_0_FN_SDEI_PE_UNMASK, 0, 0, 0, 0, 0, NULL); | |
330 | if (err && err != -EIO) { | |
331 | pr_warn_once("failed to unmask CPU[%u]: %d\n", | |
332 | smp_processor_id(), err); | |
333 | return err; | |
334 | } | |
335 | ||
336 | return 0; | |
337 | } | |
338 | ||
339 | static void _ipi_unmask_cpu(void *ignored) | |
340 | { | |
341 | sdei_unmask_local_cpu(); | |
342 | } | |
343 | ||
344 | static void _ipi_private_reset(void *ignored) | |
345 | { | |
346 | int err; | |
347 | ||
348 | err = invoke_sdei_fn(SDEI_1_0_FN_SDEI_PRIVATE_RESET, 0, 0, 0, 0, 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, 0, 0, 0, 0, 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(&_ipi_mask_cpu, NULL, true); | |
365 | sdei_firmware_call = NULL; | |
366 | } | |
367 | ||
368 | static int sdei_platform_reset(void) | |
369 | { | |
370 | int err; | |
371 | ||
372 | on_each_cpu(&_ipi_private_reset, NULL, 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, event_num, 0, 0, 0, | |
385 | 0, NULL); | |
386 | } | |
387 | ||
f92b5462 JM |
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 | WARN_ON_ONCE(preemptible()); | |
395 | ||
396 | err = sdei_api_event_enable(arg->event->event_num); | |
397 | ||
398 | sdei_cross_call_return(arg, err); | |
399 | } | |
400 | ||
ad6eb31e JM |
401 | int sdei_event_enable(u32 event_num) |
402 | { | |
403 | int err = -EINVAL; | |
404 | struct sdei_event *event; | |
405 | ||
406 | mutex_lock(&sdei_events_lock); | |
407 | event = sdei_event_find(event_num); | |
408 | if (!event) { | |
409 | mutex_unlock(&sdei_events_lock); | |
410 | return -ENOENT; | |
411 | } | |
412 | ||
da351827 JM |
413 | spin_lock(&sdei_list_lock); |
414 | event->reenable = true; | |
415 | spin_unlock(&sdei_list_lock); | |
416 | ||
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); | |
ad6eb31e JM |
421 | mutex_unlock(&sdei_events_lock); |
422 | ||
423 | return err; | |
424 | } | |
425 | EXPORT_SYMBOL(sdei_event_enable); | |
426 | ||
427 | static int sdei_api_event_disable(u32 event_num) | |
428 | { | |
429 | return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_DISABLE, event_num, 0, 0, | |
430 | 0, 0, NULL); | |
431 | } | |
432 | ||
f92b5462 JM |
433 | static void _ipi_event_disable(void *data) |
434 | { | |
435 | int err; | |
436 | struct sdei_crosscall_args *arg = data; | |
437 | ||
438 | err = sdei_api_event_disable(arg->event->event_num); | |
439 | ||
440 | sdei_cross_call_return(arg, err); | |
441 | } | |
442 | ||
ad6eb31e JM |
443 | int sdei_event_disable(u32 event_num) |
444 | { | |
445 | int err = -EINVAL; | |
446 | struct sdei_event *event; | |
447 | ||
448 | mutex_lock(&sdei_events_lock); | |
449 | event = sdei_event_find(event_num); | |
450 | if (!event) { | |
451 | mutex_unlock(&sdei_events_lock); | |
452 | return -ENOENT; | |
453 | } | |
454 | ||
da351827 JM |
455 | spin_lock(&sdei_list_lock); |
456 | event->reenable = false; | |
457 | spin_unlock(&sdei_list_lock); | |
458 | ||
ad6eb31e JM |
459 | if (event->type == SDEI_EVENT_TYPE_SHARED) |
460 | err = sdei_api_event_disable(event->event_num); | |
f92b5462 JM |
461 | else |
462 | err = sdei_do_cross_call(_ipi_event_disable, event); | |
ad6eb31e JM |
463 | mutex_unlock(&sdei_events_lock); |
464 | ||
465 | return err; | |
466 | } | |
467 | EXPORT_SYMBOL(sdei_event_disable); | |
468 | ||
469 | static int sdei_api_event_unregister(u32 event_num) | |
470 | { | |
471 | return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_UNREGISTER, event_num, 0, | |
472 | 0, 0, 0, NULL); | |
473 | } | |
474 | ||
f92b5462 JM |
475 | /* Called directly by the hotplug callbacks */ |
476 | static void _local_event_unregister(void *data) | |
477 | { | |
478 | int err; | |
479 | struct sdei_crosscall_args *arg = data; | |
480 | ||
481 | WARN_ON_ONCE(preemptible()); | |
482 | ||
483 | err = sdei_api_event_unregister(arg->event->event_num); | |
484 | ||
485 | sdei_cross_call_return(arg, err); | |
486 | } | |
487 | ||
ad6eb31e JM |
488 | static int _sdei_event_unregister(struct sdei_event *event) |
489 | { | |
490 | lockdep_assert_held(&sdei_events_lock); | |
491 | ||
da351827 JM |
492 | spin_lock(&sdei_list_lock); |
493 | event->reregister = false; | |
494 | event->reenable = false; | |
495 | spin_unlock(&sdei_list_lock); | |
496 | ||
ad6eb31e JM |
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 | ||
519 | err = _sdei_event_unregister(event); | |
520 | if (err) | |
521 | break; | |
522 | ||
523 | sdei_event_destroy(event); | |
524 | } while (0); | |
525 | mutex_unlock(&sdei_events_lock); | |
526 | ||
527 | return err; | |
528 | } | |
529 | EXPORT_SYMBOL(sdei_event_unregister); | |
530 | ||
da351827 JM |
531 | /* |
532 | * unregister events, but don't destroy them as they are re-registered by | |
533 | * sdei_reregister_shared(). | |
534 | */ | |
535 | static int sdei_unregister_shared(void) | |
536 | { | |
537 | int err = 0; | |
538 | struct sdei_event *event; | |
539 | ||
540 | mutex_lock(&sdei_events_lock); | |
541 | spin_lock(&sdei_list_lock); | |
542 | list_for_each_entry(event, &sdei_list, list) { | |
543 | if (event->type != SDEI_EVENT_TYPE_SHARED) | |
544 | continue; | |
545 | ||
546 | err = _sdei_event_unregister(event); | |
547 | if (err) | |
548 | break; | |
549 | } | |
550 | spin_unlock(&sdei_list_lock); | |
551 | mutex_unlock(&sdei_events_lock); | |
552 | ||
553 | return err; | |
554 | } | |
555 | ||
ad6eb31e JM |
556 | static int sdei_api_event_register(u32 event_num, unsigned long entry_point, |
557 | void *arg, u64 flags, u64 affinity) | |
558 | { | |
559 | return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_REGISTER, event_num, | |
560 | (unsigned long)entry_point, (unsigned long)arg, | |
561 | flags, affinity, NULL); | |
562 | } | |
563 | ||
f92b5462 JM |
564 | /* Called directly by the hotplug callbacks */ |
565 | static void _local_event_register(void *data) | |
566 | { | |
567 | int err; | |
568 | struct sdei_registered_event *reg; | |
569 | struct sdei_crosscall_args *arg = data; | |
570 | ||
571 | WARN_ON(preemptible()); | |
572 | ||
573 | reg = per_cpu_ptr(arg->event->private_registered, smp_processor_id()); | |
574 | err = sdei_api_event_register(arg->event->event_num, sdei_entry_point, | |
575 | reg, 0, 0); | |
576 | ||
577 | sdei_cross_call_return(arg, err); | |
578 | } | |
579 | ||
ad6eb31e JM |
580 | static int _sdei_event_register(struct sdei_event *event) |
581 | { | |
f92b5462 JM |
582 | int err; |
583 | ||
ad6eb31e JM |
584 | lockdep_assert_held(&sdei_events_lock); |
585 | ||
f92b5462 JM |
586 | spin_lock(&sdei_list_lock); |
587 | event->reregister = true; | |
588 | spin_unlock(&sdei_list_lock); | |
589 | ||
ad6eb31e JM |
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 JM |
596 | |
597 | err = sdei_do_cross_call(_local_event_register, event); | |
598 | if (err) { | |
599 | spin_lock(&sdei_list_lock); | |
600 | event->reregister = false; | |
601 | event->reenable = false; | |
602 | spin_unlock(&sdei_list_lock); | |
603 | ||
604 | sdei_do_cross_call(_local_event_unregister, event); | |
605 | } | |
606 | ||
607 | return err; | |
ad6eb31e JM |
608 | } |
609 | ||
610 | int sdei_event_register(u32 event_num, sdei_event_callback *cb, void *arg) | |
611 | { | |
612 | int err; | |
613 | struct sdei_event *event; | |
614 | ||
615 | WARN_ON(in_nmi()); | |
616 | ||
617 | mutex_lock(&sdei_events_lock); | |
618 | do { | |
619 | if (sdei_event_find(event_num)) { | |
620 | pr_warn("Event %u already registered\n", event_num); | |
621 | err = -EBUSY; | |
622 | break; | |
623 | } | |
624 | ||
625 | event = sdei_event_create(event_num, cb, arg); | |
626 | if (IS_ERR(event)) { | |
627 | err = PTR_ERR(event); | |
628 | pr_warn("Failed to create event %u: %d\n", event_num, | |
629 | err); | |
630 | break; | |
631 | } | |
632 | ||
633 | err = _sdei_event_register(event); | |
634 | if (err) { | |
635 | sdei_event_destroy(event); | |
636 | pr_warn("Failed to register event %u: %d\n", event_num, | |
637 | err); | |
638 | } | |
639 | } while (0); | |
640 | mutex_unlock(&sdei_events_lock); | |
641 | ||
642 | return err; | |
643 | } | |
644 | EXPORT_SYMBOL(sdei_event_register); | |
645 | ||
da351827 JM |
646 | static int sdei_reregister_event(struct sdei_event *event) |
647 | { | |
648 | int err; | |
649 | ||
650 | lockdep_assert_held(&sdei_events_lock); | |
651 | ||
652 | err = _sdei_event_register(event); | |
653 | if (err) { | |
654 | pr_err("Failed to re-register event %u\n", event->event_num); | |
655 | sdei_event_destroy(event); | |
656 | return err; | |
657 | } | |
658 | ||
659 | if (event->reenable) { | |
660 | if (event->type == SDEI_EVENT_TYPE_SHARED) | |
661 | err = sdei_api_event_enable(event->event_num); | |
f92b5462 JM |
662 | else |
663 | err = sdei_do_cross_call(_local_event_enable, event); | |
da351827 JM |
664 | } |
665 | ||
666 | if (err) | |
667 | pr_err("Failed to re-enable event %u\n", event->event_num); | |
668 | ||
669 | return err; | |
670 | } | |
671 | ||
672 | static int sdei_reregister_shared(void) | |
673 | { | |
674 | int err = 0; | |
675 | struct sdei_event *event; | |
676 | ||
677 | mutex_lock(&sdei_events_lock); | |
678 | spin_lock(&sdei_list_lock); | |
679 | list_for_each_entry(event, &sdei_list, list) { | |
680 | if (event->type != SDEI_EVENT_TYPE_SHARED) | |
681 | continue; | |
682 | ||
683 | if (event->reregister) { | |
684 | err = sdei_reregister_event(event); | |
685 | if (err) | |
686 | break; | |
687 | } | |
688 | } | |
689 | spin_unlock(&sdei_list_lock); | |
690 | mutex_unlock(&sdei_events_lock); | |
691 | ||
692 | return err; | |
693 | } | |
694 | ||
f92b5462 JM |
695 | static int sdei_cpuhp_down(unsigned int cpu) |
696 | { | |
697 | struct sdei_event *event; | |
698 | struct sdei_crosscall_args arg; | |
699 | ||
700 | /* un-register private events */ | |
701 | spin_lock(&sdei_list_lock); | |
702 | list_for_each_entry(event, &sdei_list, list) { | |
703 | if (event->type == SDEI_EVENT_TYPE_SHARED) | |
704 | continue; | |
705 | ||
706 | CROSSCALL_INIT(arg, event); | |
707 | /* call the cross-call function locally... */ | |
708 | _local_event_unregister(&arg); | |
709 | if (arg.first_error) | |
710 | pr_err("Failed to unregister event %u: %d\n", | |
711 | event->event_num, arg.first_error); | |
712 | } | |
713 | spin_unlock(&sdei_list_lock); | |
714 | ||
715 | return sdei_mask_local_cpu(); | |
716 | } | |
717 | ||
718 | static int sdei_cpuhp_up(unsigned int cpu) | |
719 | { | |
720 | struct sdei_event *event; | |
721 | struct sdei_crosscall_args arg; | |
722 | ||
723 | /* re-register/enable private events */ | |
724 | spin_lock(&sdei_list_lock); | |
725 | list_for_each_entry(event, &sdei_list, list) { | |
726 | if (event->type == SDEI_EVENT_TYPE_SHARED) | |
727 | continue; | |
728 | ||
729 | if (event->reregister) { | |
730 | CROSSCALL_INIT(arg, event); | |
731 | /* call the cross-call function locally... */ | |
732 | _local_event_register(&arg); | |
733 | if (arg.first_error) | |
734 | pr_err("Failed to re-register event %u: %d\n", | |
735 | event->event_num, arg.first_error); | |
736 | } | |
737 | ||
738 | if (event->reenable) { | |
739 | CROSSCALL_INIT(arg, event); | |
740 | _local_event_enable(&arg); | |
741 | if (arg.first_error) | |
742 | pr_err("Failed to re-enable event %u: %d\n", | |
743 | event->event_num, arg.first_error); | |
744 | } | |
745 | } | |
746 | spin_unlock(&sdei_list_lock); | |
747 | ||
748 | return sdei_unmask_local_cpu(); | |
749 | } | |
750 | ||
da351827 JM |
751 | /* When entering idle, mask/unmask events for this cpu */ |
752 | static int sdei_pm_notifier(struct notifier_block *nb, unsigned long action, | |
753 | void *data) | |
754 | { | |
755 | int rv; | |
756 | ||
757 | switch (action) { | |
758 | case CPU_PM_ENTER: | |
759 | rv = sdei_mask_local_cpu(); | |
760 | break; | |
761 | case CPU_PM_EXIT: | |
762 | case CPU_PM_ENTER_FAILED: | |
763 | rv = sdei_unmask_local_cpu(); | |
764 | break; | |
765 | default: | |
766 | return NOTIFY_DONE; | |
767 | } | |
768 | ||
769 | if (rv) | |
770 | return notifier_from_errno(rv); | |
771 | ||
772 | return NOTIFY_OK; | |
773 | } | |
774 | ||
775 | static struct notifier_block sdei_pm_nb = { | |
776 | .notifier_call = sdei_pm_notifier, | |
777 | }; | |
778 | ||
779 | static int sdei_device_suspend(struct device *dev) | |
780 | { | |
781 | on_each_cpu(_ipi_mask_cpu, NULL, true); | |
782 | ||
783 | return 0; | |
784 | } | |
785 | ||
786 | static int sdei_device_resume(struct device *dev) | |
787 | { | |
788 | on_each_cpu(_ipi_unmask_cpu, NULL, true); | |
789 | ||
790 | return 0; | |
791 | } | |
792 | ||
793 | /* | |
794 | * We need all events to be reregistered when we resume from hibernate. | |
795 | * | |
796 | * The sequence is freeze->thaw. Reboot. freeze->restore. We unregister | |
797 | * events during freeze, then re-register and re-enable them during thaw | |
798 | * and restore. | |
799 | */ | |
800 | static int sdei_device_freeze(struct device *dev) | |
801 | { | |
802 | int err; | |
803 | ||
f92b5462 | 804 | /* unregister private events */ |
da351827 JM |
805 | cpuhp_remove_state(CPUHP_AP_ARM_SDEI_STARTING); |
806 | ||
807 | err = sdei_unregister_shared(); | |
808 | if (err) | |
809 | return err; | |
810 | ||
811 | return 0; | |
812 | } | |
813 | ||
814 | static int sdei_device_thaw(struct device *dev) | |
815 | { | |
816 | int err; | |
817 | ||
818 | /* re-register shared events */ | |
819 | err = sdei_reregister_shared(); | |
820 | if (err) { | |
821 | pr_warn("Failed to re-register shared events...\n"); | |
822 | sdei_mark_interface_broken(); | |
823 | return err; | |
824 | } | |
825 | ||
826 | err = cpuhp_setup_state(CPUHP_AP_ARM_SDEI_STARTING, "SDEI", | |
827 | &sdei_cpuhp_up, &sdei_cpuhp_down); | |
828 | if (err) | |
829 | pr_warn("Failed to re-register CPU hotplug notifier...\n"); | |
830 | ||
831 | return err; | |
832 | } | |
833 | ||
834 | static int sdei_device_restore(struct device *dev) | |
835 | { | |
836 | int err; | |
837 | ||
838 | err = sdei_platform_reset(); | |
839 | if (err) | |
840 | return err; | |
841 | ||
842 | return sdei_device_thaw(dev); | |
843 | } | |
844 | ||
845 | static const struct dev_pm_ops sdei_pm_ops = { | |
846 | .suspend = sdei_device_suspend, | |
847 | .resume = sdei_device_resume, | |
848 | .freeze = sdei_device_freeze, | |
849 | .thaw = sdei_device_thaw, | |
850 | .restore = sdei_device_restore, | |
851 | }; | |
852 | ||
853 | /* | |
854 | * Mask all CPUs and unregister all events on panic, reboot or kexec. | |
855 | */ | |
856 | static int sdei_reboot_notifier(struct notifier_block *nb, unsigned long action, | |
857 | void *data) | |
858 | { | |
859 | /* | |
860 | * We are going to reset the interface, after this there is no point | |
861 | * doing work when we take CPUs offline. | |
862 | */ | |
863 | cpuhp_remove_state(CPUHP_AP_ARM_SDEI_STARTING); | |
864 | ||
865 | sdei_platform_reset(); | |
866 | ||
867 | return NOTIFY_OK; | |
868 | } | |
869 | ||
870 | static struct notifier_block sdei_reboot_nb = { | |
871 | .notifier_call = sdei_reboot_notifier, | |
872 | }; | |
873 | ||
ad6eb31e JM |
874 | static void sdei_smccc_smc(unsigned long function_id, |
875 | unsigned long arg0, unsigned long arg1, | |
876 | unsigned long arg2, unsigned long arg3, | |
877 | unsigned long arg4, struct arm_smccc_res *res) | |
878 | { | |
879 | arm_smccc_smc(function_id, arg0, arg1, arg2, arg3, arg4, 0, 0, res); | |
880 | } | |
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 | } | |
889 | ||
890 | static int sdei_get_conduit(struct platform_device *pdev) | |
891 | { | |
892 | const char *method; | |
893 | struct device_node *np = pdev->dev.of_node; | |
894 | ||
895 | sdei_firmware_call = NULL; | |
896 | if (np) { | |
897 | if (of_property_read_string(np, "method", &method)) { | |
898 | pr_warn("missing \"method\" property\n"); | |
899 | return CONDUIT_INVALID; | |
900 | } | |
901 | ||
902 | if (!strcmp("hvc", method)) { | |
903 | sdei_firmware_call = &sdei_smccc_hvc; | |
904 | return CONDUIT_HVC; | |
905 | } else if (!strcmp("smc", method)) { | |
906 | sdei_firmware_call = &sdei_smccc_smc; | |
907 | return CONDUIT_SMC; | |
908 | } | |
909 | ||
910 | pr_warn("invalid \"method\" property: %s\n", method); | |
677a60bd JM |
911 | } else if (IS_ENABLED(CONFIG_ACPI) && !acpi_disabled) { |
912 | if (acpi_psci_use_hvc()) { | |
913 | sdei_firmware_call = &sdei_smccc_hvc; | |
914 | return CONDUIT_HVC; | |
915 | } else { | |
916 | sdei_firmware_call = &sdei_smccc_smc; | |
917 | return CONDUIT_SMC; | |
918 | } | |
ad6eb31e JM |
919 | } |
920 | ||
921 | return CONDUIT_INVALID; | |
922 | } | |
923 | ||
924 | static int sdei_probe(struct platform_device *pdev) | |
925 | { | |
926 | int err; | |
927 | u64 ver = 0; | |
928 | int conduit; | |
929 | ||
930 | conduit = sdei_get_conduit(pdev); | |
931 | if (!sdei_firmware_call) | |
932 | return 0; | |
933 | ||
934 | err = sdei_api_get_version(&ver); | |
935 | if (err == -EOPNOTSUPP) | |
936 | pr_err("advertised but not implemented in platform firmware\n"); | |
937 | if (err) { | |
938 | pr_err("Failed to get SDEI version: %d\n", err); | |
939 | sdei_mark_interface_broken(); | |
940 | return err; | |
941 | } | |
942 | ||
943 | pr_info("SDEIv%d.%d (0x%x) detected in firmware.\n", | |
944 | (int)SDEI_VERSION_MAJOR(ver), (int)SDEI_VERSION_MINOR(ver), | |
945 | (int)SDEI_VERSION_VENDOR(ver)); | |
946 | ||
947 | if (SDEI_VERSION_MAJOR(ver) != 1) { | |
948 | pr_warn("Conflicting SDEI version detected.\n"); | |
949 | sdei_mark_interface_broken(); | |
950 | return -EINVAL; | |
951 | } | |
952 | ||
953 | err = sdei_platform_reset(); | |
954 | if (err) | |
955 | return err; | |
956 | ||
957 | sdei_entry_point = sdei_arch_get_entry_point(conduit); | |
958 | if (!sdei_entry_point) { | |
959 | /* Not supported due to hardware or boot configuration */ | |
960 | sdei_mark_interface_broken(); | |
961 | return 0; | |
962 | } | |
963 | ||
da351827 JM |
964 | err = cpu_pm_register_notifier(&sdei_pm_nb); |
965 | if (err) { | |
966 | pr_warn("Failed to register CPU PM notifier...\n"); | |
967 | goto error; | |
968 | } | |
969 | ||
970 | err = register_reboot_notifier(&sdei_reboot_nb); | |
971 | if (err) { | |
972 | pr_warn("Failed to register reboot notifier...\n"); | |
973 | goto remove_cpupm; | |
974 | } | |
975 | ||
976 | err = cpuhp_setup_state(CPUHP_AP_ARM_SDEI_STARTING, "SDEI", | |
977 | &sdei_cpuhp_up, &sdei_cpuhp_down); | |
978 | if (err) { | |
979 | pr_warn("Failed to register CPU hotplug notifier...\n"); | |
980 | goto remove_reboot; | |
981 | } | |
ad6eb31e JM |
982 | |
983 | return 0; | |
da351827 JM |
984 | |
985 | remove_reboot: | |
986 | unregister_reboot_notifier(&sdei_reboot_nb); | |
987 | ||
988 | remove_cpupm: | |
989 | cpu_pm_unregister_notifier(&sdei_pm_nb); | |
990 | ||
991 | error: | |
992 | sdei_mark_interface_broken(); | |
993 | return err; | |
ad6eb31e JM |
994 | } |
995 | ||
996 | static const struct of_device_id sdei_of_match[] = { | |
997 | { .compatible = "arm,sdei-1.0" }, | |
998 | {} | |
999 | }; | |
1000 | ||
1001 | static struct platform_driver sdei_driver = { | |
1002 | .driver = { | |
1003 | .name = "sdei", | |
da351827 | 1004 | .pm = &sdei_pm_ops, |
ad6eb31e JM |
1005 | .of_match_table = sdei_of_match, |
1006 | }, | |
1007 | .probe = sdei_probe, | |
1008 | }; | |
1009 | ||
1010 | static bool __init sdei_present_dt(void) | |
1011 | { | |
1012 | struct platform_device *pdev; | |
1013 | struct device_node *np, *fw_np; | |
1014 | ||
1015 | fw_np = of_find_node_by_name(NULL, "firmware"); | |
1016 | if (!fw_np) | |
1017 | return false; | |
1018 | ||
1019 | np = of_find_matching_node(fw_np, sdei_of_match); | |
1020 | of_node_put(fw_np); | |
1021 | if (!np) | |
1022 | return false; | |
1023 | ||
1024 | pdev = of_platform_device_create(np, sdei_driver.driver.name, NULL); | |
1025 | of_node_put(np); | |
2f7aacf7 | 1026 | if (!pdev) |
ad6eb31e JM |
1027 | return false; |
1028 | ||
1029 | return true; | |
1030 | } | |
1031 | ||
677a60bd JM |
1032 | static bool __init sdei_present_acpi(void) |
1033 | { | |
1034 | acpi_status status; | |
1035 | struct platform_device *pdev; | |
1036 | struct acpi_table_header *sdei_table_header; | |
1037 | ||
1038 | if (acpi_disabled) | |
1039 | return false; | |
1040 | ||
1041 | status = acpi_get_table(ACPI_SIG_SDEI, 0, &sdei_table_header); | |
1042 | if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) { | |
1043 | const char *msg = acpi_format_exception(status); | |
1044 | ||
1045 | pr_info("Failed to get ACPI:SDEI table, %s\n", msg); | |
1046 | } | |
1047 | if (ACPI_FAILURE(status)) | |
1048 | return false; | |
1049 | ||
1050 | pdev = platform_device_register_simple(sdei_driver.driver.name, 0, NULL, | |
1051 | 0); | |
1052 | if (IS_ERR(pdev)) | |
1053 | return false; | |
1054 | ||
1055 | return true; | |
1056 | } | |
1057 | ||
ad6eb31e JM |
1058 | static int __init sdei_init(void) |
1059 | { | |
677a60bd | 1060 | if (sdei_present_dt() || sdei_present_acpi()) |
ad6eb31e JM |
1061 | platform_driver_register(&sdei_driver); |
1062 | ||
1063 | return 0; | |
1064 | } | |
1065 | ||
677a60bd JM |
1066 | /* |
1067 | * On an ACPI system SDEI needs to be ready before HEST:GHES tries to register | |
1068 | * its events. ACPI is initialised from a subsys_initcall(), GHES is initialised | |
1069 | * by device_initcall(). We want to be called in the middle. | |
1070 | */ | |
ad6eb31e JM |
1071 | subsys_initcall_sync(sdei_init); |
1072 | ||
1073 | int sdei_event_handler(struct pt_regs *regs, | |
1074 | struct sdei_registered_event *arg) | |
1075 | { | |
1076 | int err; | |
1077 | mm_segment_t orig_addr_limit; | |
1078 | u32 event_num = arg->event_num; | |
1079 | ||
1080 | orig_addr_limit = get_fs(); | |
1081 | set_fs(USER_DS); | |
1082 | ||
1083 | err = arg->callback(event_num, regs, arg->callback_arg); | |
1084 | if (err) | |
1085 | pr_err_ratelimited("event %u on CPU %u failed with error: %d\n", | |
1086 | event_num, smp_processor_id(), err); | |
1087 | ||
1088 | set_fs(orig_addr_limit); | |
1089 | ||
1090 | return err; | |
1091 | } | |
1092 | NOKPROBE_SYMBOL(sdei_event_handler); |