1// SPDX-License-Identifier: GPL-2.0 OR MIT
2/*
3 * Copyright 2014-2022 Advanced Micro Devices, Inc.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be included in
13 * all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
19 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
20 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
21 * OTHER DEALINGS IN THE SOFTWARE.
22 */
23
24#include <linux/mm_types.h>
25#include <linux/slab.h>
26#include <linux/types.h>
27#include <linux/sched/signal.h>
28#include <linux/sched/mm.h>
29#include <linux/uaccess.h>
30#include <linux/mman.h>
31#include <linux/memory.h>
32#include "kfd_priv.h"
33#include "kfd_events.h"
34#include <linux/device.h>
35
36/*
37 * Wrapper around wait_queue_entry_t
38 */
39struct kfd_event_waiter {
40	wait_queue_entry_t wait;
41	struct kfd_event *event; /* Event to wait for */
42	bool activated;		 /* Becomes true when event is signaled */
43	bool event_age_enabled;  /* set to true when last_event_age is non-zero */
44};
45
46/*
47 * Each signal event needs a 64-bit signal slot where the signaler will write
48 * a 1 before sending an interrupt. (This is needed because some interrupts
49 * do not contain enough spare data bits to identify an event.)
50 * We get whole pages and map them to the process VA.
51 * Individual signal events use their event_id as slot index.
52 */
53struct kfd_signal_page {
54	uint64_t *kernel_address;
55	uint64_t __user *user_address;
56	bool need_to_free_pages;
57};
58
59static uint64_t *page_slots(struct kfd_signal_page *page)
60{
61	return page->kernel_address;
62}
63
64static struct kfd_signal_page *allocate_signal_page(struct kfd_process *p)
65{
66	void *backing_store;
67	struct kfd_signal_page *page;
68
69	page = kzalloc(sizeof(*page), GFP_KERNEL);
70	if (!page)
71		return NULL;
72
73	backing_store = (void *) __get_free_pages(GFP_KERNEL,
74					get_order(KFD_SIGNAL_EVENT_LIMIT * 8));
75	if (!backing_store)
76		goto fail_alloc_signal_store;
77
78	/* Initialize all events to unsignaled */
79	memset(backing_store, (uint8_t) UNSIGNALED_EVENT_SLOT,
80	       KFD_SIGNAL_EVENT_LIMIT * 8);
81
82	page->kernel_address = backing_store;
83	page->need_to_free_pages = true;
84	pr_debug("Allocated new event signal page at %p, for process %p\n",
85			page, p);
86
87	return page;
88
89fail_alloc_signal_store:
90	kfree(page);
91	return NULL;
92}
93
94static int allocate_event_notification_slot(struct kfd_process *p,
95					    struct kfd_event *ev,
96					    const int *restore_id)
97{
98	int id;
99
100	if (!p->signal_page) {
101		p->signal_page = allocate_signal_page(p);
102		if (!p->signal_page)
103			return -ENOMEM;
104		/* Oldest user mode expects 256 event slots */
105		p->signal_mapped_size = 256*8;
106	}
107
108	if (restore_id) {
109		id = idr_alloc(&p->event_idr, ev, *restore_id, *restore_id + 1,
110				GFP_KERNEL);
111	} else {
112		/*
113		 * Compatibility with old user mode: Only use signal slots
114		 * user mode has mapped, may be less than
115		 * KFD_SIGNAL_EVENT_LIMIT. This also allows future increase
116		 * of the event limit without breaking user mode.
117		 */
118		id = idr_alloc(&p->event_idr, ev, 0, p->signal_mapped_size / 8,
119				GFP_KERNEL);
120	}
121	if (id < 0)
122		return id;
123
124	ev->event_id = id;
125	page_slots(p->signal_page)[id] = UNSIGNALED_EVENT_SLOT;
126
127	return 0;
128}
129
130/*
131 * Assumes that p->event_mutex or rcu_readlock is held and of course that p is
132 * not going away.
133 */
134static struct kfd_event *lookup_event_by_id(struct kfd_process *p, uint32_t id)
135{
136	return idr_find(&p->event_idr, id);
137}
138
139/**
140 * lookup_signaled_event_by_partial_id - Lookup signaled event from partial ID
141 * @p:     Pointer to struct kfd_process
142 * @id:    ID to look up
143 * @bits:  Number of valid bits in @id
144 *
145 * Finds the first signaled event with a matching partial ID. If no
146 * matching signaled event is found, returns NULL. In that case the
147 * caller should assume that the partial ID is invalid and do an
148 * exhaustive search of all siglaned events.
149 *
150 * If multiple events with the same partial ID signal at the same
151 * time, they will be found one interrupt at a time, not necessarily
152 * in the same order the interrupts occurred. As long as the number of
153 * interrupts is correct, all signaled events will be seen by the
154 * driver.
155 */
156static struct kfd_event *lookup_signaled_event_by_partial_id(
157	struct kfd_process *p, uint32_t id, uint32_t bits)
158{
159	struct kfd_event *ev;
160
161	if (!p->signal_page || id >= KFD_SIGNAL_EVENT_LIMIT)
162		return NULL;
163
164	/* Fast path for the common case that @id is not a partial ID
165	 * and we only need a single lookup.
166	 */
167	if (bits > 31 || (1U << bits) >= KFD_SIGNAL_EVENT_LIMIT) {
168		if (page_slots(p->signal_page)[id] == UNSIGNALED_EVENT_SLOT)
169			return NULL;
170
171		return idr_find(&p->event_idr, id);
172	}
173
174	/* General case for partial IDs: Iterate over all matching IDs
175	 * and find the first one that has signaled.
176	 */
177	for (ev = NULL; id < KFD_SIGNAL_EVENT_LIMIT && !ev; id += 1U << bits) {
178		if (page_slots(p->signal_page)[id] == UNSIGNALED_EVENT_SLOT)
179			continue;
180
181		ev = idr_find(&p->event_idr, id);
182	}
183
184	return ev;
185}
186
187static int create_signal_event(struct file *devkfd, struct kfd_process *p,
188				struct kfd_event *ev, const int *restore_id)
189{
190	int ret;
191
192	if (p->signal_mapped_size &&
193	    p->signal_event_count == p->signal_mapped_size / 8) {
194		if (!p->signal_event_limit_reached) {
195			pr_debug("Signal event wasn't created because limit was reached\n");
196			p->signal_event_limit_reached = true;
197		}
198		return -ENOSPC;
199	}
200
201	ret = allocate_event_notification_slot(p, ev, restore_id);
202	if (ret) {
203		pr_warn("Signal event wasn't created because out of kernel memory\n");
204		return ret;
205	}
206
207	p->signal_event_count++;
208
209	ev->user_signal_address = &p->signal_page->user_address[ev->event_id];
210	pr_debug("Signal event number %zu created with id %d, address %p\n",
211			p->signal_event_count, ev->event_id,
212			ev->user_signal_address);
213
214	return 0;
215}
216
217static int create_other_event(struct kfd_process *p, struct kfd_event *ev, const int *restore_id)
218{
219	int id;
220
221	if (restore_id)
222		id = idr_alloc(&p->event_idr, ev, *restore_id, *restore_id + 1,
223			GFP_KERNEL);
224	else
225		/* Cast KFD_LAST_NONSIGNAL_EVENT to uint32_t. This allows an
226		 * intentional integer overflow to -1 without a compiler
227		 * warning. idr_alloc treats a negative value as "maximum
228		 * signed integer".
229		 */
230		id = idr_alloc(&p->event_idr, ev, KFD_FIRST_NONSIGNAL_EVENT_ID,
231				(uint32_t)KFD_LAST_NONSIGNAL_EVENT_ID + 1,
232				GFP_KERNEL);
233
234	if (id < 0)
235		return id;
236	ev->event_id = id;
237
238	return 0;
239}
240
241int kfd_event_init_process(struct kfd_process *p)
242{
243	int id;
244
245	mutex_init(&p->event_mutex);
246	idr_init(&p->event_idr);
247	p->signal_page = NULL;
248	p->signal_event_count = 1;
249	/* Allocate event ID 0. It is used for a fast path to ignore bogus events
250	 * that are sent by the CP without a context ID
251	 */
252	id = idr_alloc(&p->event_idr, NULL, 0, 1, GFP_KERNEL);
253	if (id < 0) {
254		idr_destroy(&p->event_idr);
255		mutex_destroy(&p->event_mutex);
256		return id;
257	}
258	return 0;
259}
260
261static void destroy_event(struct kfd_process *p, struct kfd_event *ev)
262{
263	struct kfd_event_waiter *waiter;
264
265	/* Wake up pending waiters. They will return failure */
266	spin_lock(&ev->lock);
267	list_for_each_entry(waiter, &ev->wq.head, wait.entry)
268		WRITE_ONCE(waiter->event, NULL);
269	wake_up_all(&ev->wq);
270	spin_unlock(&ev->lock);
271
272	if (ev->type == KFD_EVENT_TYPE_SIGNAL ||
273	    ev->type == KFD_EVENT_TYPE_DEBUG)
274		p->signal_event_count--;
275
276	idr_remove(&p->event_idr, ev->event_id);
277	kfree_rcu(ev, rcu);
278}
279
280static void destroy_events(struct kfd_process *p)
281{
282	struct kfd_event *ev;
283	uint32_t id;
284
285	idr_for_each_entry(&p->event_idr, ev, id)
286		if (ev)
287			destroy_event(p, ev);
288	idr_destroy(&p->event_idr);
289	mutex_destroy(&p->event_mutex);
290}
291
292/*
293 * We assume that the process is being destroyed and there is no need to
294 * unmap the pages or keep bookkeeping data in order.
295 */
296static void shutdown_signal_page(struct kfd_process *p)
297{
298	struct kfd_signal_page *page = p->signal_page;
299
300	if (page) {
301		if (page->need_to_free_pages)
302			free_pages((unsigned long)page->kernel_address,
303				   get_order(KFD_SIGNAL_EVENT_LIMIT * 8));
304		kfree(page);
305	}
306}
307
308void kfd_event_free_process(struct kfd_process *p)
309{
310	destroy_events(p);
311	shutdown_signal_page(p);
312}
313
314static bool event_can_be_gpu_signaled(const struct kfd_event *ev)
315{
316	return ev->type == KFD_EVENT_TYPE_SIGNAL ||
317					ev->type == KFD_EVENT_TYPE_DEBUG;
318}
319
320static bool event_can_be_cpu_signaled(const struct kfd_event *ev)
321{
322	return ev->type == KFD_EVENT_TYPE_SIGNAL;
323}
324
325static int kfd_event_page_set(struct kfd_process *p, void *kernel_address,
326		       uint64_t size, uint64_t user_handle)
327{
328	struct kfd_signal_page *page;
329
330	if (p->signal_page)
331		return -EBUSY;
332
333	page = kzalloc(sizeof(*page), GFP_KERNEL);
334	if (!page)
335		return -ENOMEM;
336
337	/* Initialize all events to unsignaled */
338	memset(kernel_address, (uint8_t) UNSIGNALED_EVENT_SLOT,
339	       KFD_SIGNAL_EVENT_LIMIT * 8);
340
341	page->kernel_address = kernel_address;
342
343	p->signal_page = page;
344	p->signal_mapped_size = size;
345	p->signal_handle = user_handle;
346	return 0;
347}
348
349int kfd_kmap_event_page(struct kfd_process *p, uint64_t event_page_offset)
350{
351	struct kfd_node *kfd;
352	struct kfd_process_device *pdd;
353	void *mem, *kern_addr;
354	uint64_t size;
355	int err = 0;
356
357	if (p->signal_page) {
358		pr_err("Event page is already set\n");
359		return -EINVAL;
360	}
361
362	pdd = kfd_process_device_data_by_id(p, GET_GPU_ID(event_page_offset));
363	if (!pdd) {
364		pr_err("Getting device by id failed in %s\n", __func__);
365		return -EINVAL;
366	}
367	kfd = pdd->dev;
368
369	pdd = kfd_bind_process_to_device(kfd, p);
370	if (IS_ERR(pdd))
371		return PTR_ERR(pdd);
372
373	mem = kfd_process_device_translate_handle(pdd,
374			GET_IDR_HANDLE(event_page_offset));
375	if (!mem) {
376		pr_err("Can't find BO, offset is 0x%llx\n", event_page_offset);
377		return -EINVAL;
378	}
379
380	err = amdgpu_amdkfd_gpuvm_map_gtt_bo_to_kernel(mem, &kern_addr, &size);
381	if (err) {
382		pr_err("Failed to map event page to kernel\n");
383		return err;
384	}
385
386	err = kfd_event_page_set(p, kern_addr, size, event_page_offset);
387	if (err) {
388		pr_err("Failed to set event page\n");
389		amdgpu_amdkfd_gpuvm_unmap_gtt_bo_from_kernel(mem);
390		return err;
391	}
392	return err;
393}
394
395int kfd_event_create(struct file *devkfd, struct kfd_process *p,
396		     uint32_t event_type, bool auto_reset, uint32_t node_id,
397		     uint32_t *event_id, uint32_t *event_trigger_data,
398		     uint64_t *event_page_offset, uint32_t *event_slot_index)
399{
400	int ret = 0;
401	struct kfd_event *ev = kzalloc(sizeof(*ev), GFP_KERNEL);
402
403	if (!ev)
404		return -ENOMEM;
405
406	ev->type = event_type;
407	ev->auto_reset = auto_reset;
408	ev->signaled = false;
409
410	spin_lock_init(&ev->lock);
411	init_waitqueue_head(&ev->wq);
412
413	*event_page_offset = 0;
414
415	mutex_lock(&p->event_mutex);
416
417	switch (event_type) {
418	case KFD_EVENT_TYPE_SIGNAL:
419	case KFD_EVENT_TYPE_DEBUG:
420		ret = create_signal_event(devkfd, p, ev, NULL);
421		if (!ret) {
422			*event_page_offset = KFD_MMAP_TYPE_EVENTS;
423			*event_slot_index = ev->event_id;
424		}
425		break;
426	default:
427		ret = create_other_event(p, ev, NULL);
428		break;
429	}
430
431	if (!ret) {
432		*event_id = ev->event_id;
433		*event_trigger_data = ev->event_id;
434		ev->event_age = 1;
435	} else {
436		kfree(ev);
437	}
438
439	mutex_unlock(&p->event_mutex);
440
441	return ret;
442}
443
444int kfd_criu_restore_event(struct file *devkfd,
445			   struct kfd_process *p,
446			   uint8_t __user *user_priv_ptr,
447			   uint64_t *priv_data_offset,
448			   uint64_t max_priv_data_size)
449{
450	struct kfd_criu_event_priv_data *ev_priv;
451	struct kfd_event *ev = NULL;
452	int ret = 0;
453
454	ev_priv = kmalloc(sizeof(*ev_priv), GFP_KERNEL);
455	if (!ev_priv)
456		return -ENOMEM;
457
458	ev = kzalloc(sizeof(*ev), GFP_KERNEL);
459	if (!ev) {
460		ret = -ENOMEM;
461		goto exit;
462	}
463
464	if (*priv_data_offset + sizeof(*ev_priv) > max_priv_data_size) {
465		ret = -EINVAL;
466		goto exit;
467	}
468
469	ret = copy_from_user(ev_priv, user_priv_ptr + *priv_data_offset, sizeof(*ev_priv));
470	if (ret) {
471		ret = -EFAULT;
472		goto exit;
473	}
474	*priv_data_offset += sizeof(*ev_priv);
475
476	if (ev_priv->user_handle) {
477		ret = kfd_kmap_event_page(p, ev_priv->user_handle);
478		if (ret)
479			goto exit;
480	}
481
482	ev->type = ev_priv->type;
483	ev->auto_reset = ev_priv->auto_reset;
484	ev->signaled = ev_priv->signaled;
485
486	spin_lock_init(&ev->lock);
487	init_waitqueue_head(&ev->wq);
488
489	mutex_lock(&p->event_mutex);
490	switch (ev->type) {
491	case KFD_EVENT_TYPE_SIGNAL:
492	case KFD_EVENT_TYPE_DEBUG:
493		ret = create_signal_event(devkfd, p, ev, &ev_priv->event_id);
494		break;
495	case KFD_EVENT_TYPE_MEMORY:
496		memcpy(&ev->memory_exception_data,
497			&ev_priv->memory_exception_data,
498			sizeof(struct kfd_hsa_memory_exception_data));
499
500		ret = create_other_event(p, ev, &ev_priv->event_id);
501		break;
502	case KFD_EVENT_TYPE_HW_EXCEPTION:
503		memcpy(&ev->hw_exception_data,
504			&ev_priv->hw_exception_data,
505			sizeof(struct kfd_hsa_hw_exception_data));
506
507		ret = create_other_event(p, ev, &ev_priv->event_id);
508		break;
509	}
510	mutex_unlock(&p->event_mutex);
511
512exit:
513	if (ret)
514		kfree(ev);
515
516	kfree(ev_priv);
517
518	return ret;
519}
520
521int kfd_criu_checkpoint_events(struct kfd_process *p,
522			 uint8_t __user *user_priv_data,
523			 uint64_t *priv_data_offset)
524{
525	struct kfd_criu_event_priv_data *ev_privs;
526	int i = 0;
527	int ret =  0;
528	struct kfd_event *ev;
529	uint32_t ev_id;
530
531	uint32_t num_events = kfd_get_num_events(p);
532
533	if (!num_events)
534		return 0;
535
536	ev_privs = kvzalloc(num_events * sizeof(*ev_privs), GFP_KERNEL);
537	if (!ev_privs)
538		return -ENOMEM;
539
540
541	idr_for_each_entry(&p->event_idr, ev, ev_id) {
542		struct kfd_criu_event_priv_data *ev_priv;
543
544		/*
545		 * Currently, all events have same size of private_data, but the current ioctl's
546		 * and CRIU plugin supports private_data of variable sizes
547		 */
548		ev_priv = &ev_privs[i];
549
550		ev_priv->object_type = KFD_CRIU_OBJECT_TYPE_EVENT;
551
552		/* We store the user_handle with the first event */
553		if (i == 0 && p->signal_page)
554			ev_priv->user_handle = p->signal_handle;
555
556		ev_priv->event_id = ev->event_id;
557		ev_priv->auto_reset = ev->auto_reset;
558		ev_priv->type = ev->type;
559		ev_priv->signaled = ev->signaled;
560
561		if (ev_priv->type == KFD_EVENT_TYPE_MEMORY)
562			memcpy(&ev_priv->memory_exception_data,
563				&ev->memory_exception_data,
564				sizeof(struct kfd_hsa_memory_exception_data));
565		else if (ev_priv->type == KFD_EVENT_TYPE_HW_EXCEPTION)
566			memcpy(&ev_priv->hw_exception_data,
567				&ev->hw_exception_data,
568				sizeof(struct kfd_hsa_hw_exception_data));
569
570		pr_debug("Checkpointed event[%d] id = 0x%08x auto_reset = %x type = %x signaled = %x\n",
571			  i,
572			  ev_priv->event_id,
573			  ev_priv->auto_reset,
574			  ev_priv->type,
575			  ev_priv->signaled);
576		i++;
577	}
578
579	ret = copy_to_user(user_priv_data + *priv_data_offset,
580			   ev_privs, num_events * sizeof(*ev_privs));
581	if (ret) {
582		pr_err("Failed to copy events priv to user\n");
583		ret = -EFAULT;
584	}
585
586	*priv_data_offset += num_events * sizeof(*ev_privs);
587
588	kvfree(ev_privs);
589	return ret;
590}
591
592int kfd_get_num_events(struct kfd_process *p)
593{
594	struct kfd_event *ev;
595	uint32_t id;
596	u32 num_events = 0;
597
598	idr_for_each_entry(&p->event_idr, ev, id)
599		num_events++;
600
601	return num_events;
602}
603
604/* Assumes that p is current. */
605int kfd_event_destroy(struct kfd_process *p, uint32_t event_id)
606{
607	struct kfd_event *ev;
608	int ret = 0;
609
610	mutex_lock(&p->event_mutex);
611
612	ev = lookup_event_by_id(p, event_id);
613
614	if (ev)
615		destroy_event(p, ev);
616	else
617		ret = -EINVAL;
618
619	mutex_unlock(&p->event_mutex);
620	return ret;
621}
622
623static void set_event(struct kfd_event *ev)
624{
625	struct kfd_event_waiter *waiter;
626
627	/* Auto reset if the list is non-empty and we're waking
628	 * someone. waitqueue_active is safe here because we're
629	 * protected by the ev->lock, which is also held when
630	 * updating the wait queues in kfd_wait_on_events.
631	 */
632	ev->signaled = !ev->auto_reset || !waitqueue_active(&ev->wq);
633	if (!(++ev->event_age)) {
634		/* Never wrap back to reserved/default event age 0/1 */
635		ev->event_age = 2;
636		WARN_ONCE(1, "event_age wrap back!");
637	}
638
639	list_for_each_entry(waiter, &ev->wq.head, wait.entry)
640		WRITE_ONCE(waiter->activated, true);
641
642	wake_up_all(&ev->wq);
643}
644
645/* Assumes that p is current. */
646int kfd_set_event(struct kfd_process *p, uint32_t event_id)
647{
648	int ret = 0;
649	struct kfd_event *ev;
650
651	rcu_read_lock();
652
653	ev = lookup_event_by_id(p, event_id);
654	if (!ev) {
655		ret = -EINVAL;
656		goto unlock_rcu;
657	}
658	spin_lock(&ev->lock);
659
660	if (event_can_be_cpu_signaled(ev))
661		set_event(ev);
662	else
663		ret = -EINVAL;
664
665	spin_unlock(&ev->lock);
666unlock_rcu:
667	rcu_read_unlock();
668	return ret;
669}
670
671static void reset_event(struct kfd_event *ev)
672{
673	ev->signaled = false;
674}
675
676/* Assumes that p is current. */
677int kfd_reset_event(struct kfd_process *p, uint32_t event_id)
678{
679	int ret = 0;
680	struct kfd_event *ev;
681
682	rcu_read_lock();
683
684	ev = lookup_event_by_id(p, event_id);
685	if (!ev) {
686		ret = -EINVAL;
687		goto unlock_rcu;
688	}
689	spin_lock(&ev->lock);
690
691	if (event_can_be_cpu_signaled(ev))
692		reset_event(ev);
693	else
694		ret = -EINVAL;
695
696	spin_unlock(&ev->lock);
697unlock_rcu:
698	rcu_read_unlock();
699	return ret;
700
701}
702
703static void acknowledge_signal(struct kfd_process *p, struct kfd_event *ev)
704{
705	WRITE_ONCE(page_slots(p->signal_page)[ev->event_id], UNSIGNALED_EVENT_SLOT);
706}
707
708static void set_event_from_interrupt(struct kfd_process *p,
709					struct kfd_event *ev)
710{
711	if (ev && event_can_be_gpu_signaled(ev)) {
712		acknowledge_signal(p, ev);
713		spin_lock(&ev->lock);
714		set_event(ev);
715		spin_unlock(&ev->lock);
716	}
717}
718
719void kfd_signal_event_interrupt(u32 pasid, uint32_t partial_id,
720				uint32_t valid_id_bits)
721{
722	struct kfd_event *ev = NULL;
723
724	/*
725	 * Because we are called from arbitrary context (workqueue) as opposed
726	 * to process context, kfd_process could attempt to exit while we are
727	 * running so the lookup function increments the process ref count.
728	 */
729	struct kfd_process *p = kfd_lookup_process_by_pasid(pasid);
730
731	if (!p)
732		return; /* Presumably process exited. */
733
734	rcu_read_lock();
735
736	if (valid_id_bits)
737		ev = lookup_signaled_event_by_partial_id(p, partial_id,
738							 valid_id_bits);
739	if (ev) {
740		set_event_from_interrupt(p, ev);
741	} else if (p->signal_page) {
742		/*
743		 * Partial ID lookup failed. Assume that the event ID
744		 * in the interrupt payload was invalid and do an
745		 * exhaustive search of signaled events.
746		 */
747		uint64_t *slots = page_slots(p->signal_page);
748		uint32_t id;
749
750		if (valid_id_bits)
751			pr_debug_ratelimited("Partial ID invalid: %u (%u valid bits)\n",
752					     partial_id, valid_id_bits);
753
754		if (p->signal_event_count < KFD_SIGNAL_EVENT_LIMIT / 64) {
755			/* With relatively few events, it's faster to
756			 * iterate over the event IDR
757			 */
758			idr_for_each_entry(&p->event_idr, ev, id) {
759				if (id >= KFD_SIGNAL_EVENT_LIMIT)
760					break;
761
762				if (READ_ONCE(slots[id]) != UNSIGNALED_EVENT_SLOT)
763					set_event_from_interrupt(p, ev);
764			}
765		} else {
766			/* With relatively many events, it's faster to
767			 * iterate over the signal slots and lookup
768			 * only signaled events from the IDR.
769			 */
770			for (id = 1; id < KFD_SIGNAL_EVENT_LIMIT; id++)
771				if (READ_ONCE(slots[id]) != UNSIGNALED_EVENT_SLOT) {
772					ev = lookup_event_by_id(p, id);
773					set_event_from_interrupt(p, ev);
774				}
775		}
776	}
777
778	rcu_read_unlock();
779	kfd_unref_process(p);
780}
781
782static struct kfd_event_waiter *alloc_event_waiters(uint32_t num_events)
783{
784	struct kfd_event_waiter *event_waiters;
785	uint32_t i;
786
787	event_waiters = kcalloc(num_events, sizeof(struct kfd_event_waiter),
788				GFP_KERNEL);
789	if (!event_waiters)
790		return NULL;
791
792	for (i = 0; i < num_events; i++)
793		init_wait(&event_waiters[i].wait);
794
795	return event_waiters;
796}
797
798static int init_event_waiter(struct kfd_process *p,
799		struct kfd_event_waiter *waiter,
800		struct kfd_event_data *event_data)
801{
802	struct kfd_event *ev = lookup_event_by_id(p, event_data->event_id);
803
804	if (!ev)
805		return -EINVAL;
806
807	spin_lock(&ev->lock);
808	waiter->event = ev;
809	waiter->activated = ev->signaled;
810	ev->signaled = ev->signaled && !ev->auto_reset;
811
812	/* last_event_age = 0 reserved for backward compatible */
813	if (waiter->event->type == KFD_EVENT_TYPE_SIGNAL &&
814		event_data->signal_event_data.last_event_age) {
815		waiter->event_age_enabled = true;
816		if (ev->event_age != event_data->signal_event_data.last_event_age)
817			waiter->activated = true;
818	}
819
820	if (!waiter->activated)
821		add_wait_queue(&ev->wq, &waiter->wait);
822	spin_unlock(&ev->lock);
823
824	return 0;
825}
826
827/* test_event_condition - Test condition of events being waited for
828 * @all:           Return completion only if all events have signaled
829 * @num_events:    Number of events to wait for
830 * @event_waiters: Array of event waiters, one per event
831 *
832 * Returns KFD_IOC_WAIT_RESULT_COMPLETE if all (or one) event(s) have
833 * signaled. Returns KFD_IOC_WAIT_RESULT_TIMEOUT if no (or not all)
834 * events have signaled. Returns KFD_IOC_WAIT_RESULT_FAIL if any of
835 * the events have been destroyed.
836 */
837static uint32_t test_event_condition(bool all, uint32_t num_events,
838				struct kfd_event_waiter *event_waiters)
839{
840	uint32_t i;
841	uint32_t activated_count = 0;
842
843	for (i = 0; i < num_events; i++) {
844		if (!READ_ONCE(event_waiters[i].event))
845			return KFD_IOC_WAIT_RESULT_FAIL;
846
847		if (READ_ONCE(event_waiters[i].activated)) {
848			if (!all)
849				return KFD_IOC_WAIT_RESULT_COMPLETE;
850
851			activated_count++;
852		}
853	}
854
855	return activated_count == num_events ?
856		KFD_IOC_WAIT_RESULT_COMPLETE : KFD_IOC_WAIT_RESULT_TIMEOUT;
857}
858
859/*
860 * Copy event specific data, if defined.
861 * Currently only memory exception events have additional data to copy to user
862 */
863static int copy_signaled_event_data(uint32_t num_events,
864		struct kfd_event_waiter *event_waiters,
865		struct kfd_event_data __user *data)
866{
867	void *src;
868	void __user *dst;
869	struct kfd_event_waiter *waiter;
870	struct kfd_event *event;
871	uint32_t i, size = 0;
872
873	for (i = 0; i < num_events; i++) {
874		waiter = &event_waiters[i];
875		event = waiter->event;
876		if (!event)
877			return -EINVAL; /* event was destroyed */
878		if (waiter->activated) {
879			if (event->type == KFD_EVENT_TYPE_MEMORY) {
880				dst = &data[i].memory_exception_data;
881				src = &event->memory_exception_data;
882				size = sizeof(struct kfd_hsa_memory_exception_data);
883			} else if (event->type == KFD_EVENT_TYPE_SIGNAL &&
884				waiter->event_age_enabled) {
885				dst = &data[i].signal_event_data.last_event_age;
886				src = &event->event_age;
887				size = sizeof(u64);
888			}
889			if (size && copy_to_user(dst, src, size))
890				return -EFAULT;
891		}
892	}
893
894	return 0;
895}
896
897static long user_timeout_to_jiffies(uint32_t user_timeout_ms)
898{
899	if (user_timeout_ms == KFD_EVENT_TIMEOUT_IMMEDIATE)
900		return 0;
901
902	if (user_timeout_ms == KFD_EVENT_TIMEOUT_INFINITE)
903		return MAX_SCHEDULE_TIMEOUT;
904
905	/*
906	 * msecs_to_jiffies interprets all values above 2^31-1 as infinite,
907	 * but we consider them finite.
908	 * This hack is wrong, but nobody is likely to notice.
909	 */
910	user_timeout_ms = min_t(uint32_t, user_timeout_ms, 0x7FFFFFFF);
911
912	return msecs_to_jiffies(user_timeout_ms) + 1;
913}
914
915static void free_waiters(uint32_t num_events, struct kfd_event_waiter *waiters,
916			 bool undo_auto_reset)
917{
918	uint32_t i;
919
920	for (i = 0; i < num_events; i++)
921		if (waiters[i].event) {
922			spin_lock(&waiters[i].event->lock);
923			remove_wait_queue(&waiters[i].event->wq,
924					  &waiters[i].wait);
925			if (undo_auto_reset && waiters[i].activated &&
926			    waiters[i].event && waiters[i].event->auto_reset)
927				set_event(waiters[i].event);
928			spin_unlock(&waiters[i].event->lock);
929		}
930
931	kfree(waiters);
932}
933
934int kfd_wait_on_events(struct kfd_process *p,
935		       uint32_t num_events, void __user *data,
936		       bool all, uint32_t *user_timeout_ms,
937		       uint32_t *wait_result)
938{
939	struct kfd_event_data __user *events =
940			(struct kfd_event_data __user *) data;
941	uint32_t i;
942	int ret = 0;
943
944	struct kfd_event_waiter *event_waiters = NULL;
945	long timeout = user_timeout_to_jiffies(*user_timeout_ms);
946
947	event_waiters = alloc_event_waiters(num_events);
948	if (!event_waiters) {
949		ret = -ENOMEM;
950		goto out;
951	}
952
953	/* Use p->event_mutex here to protect against concurrent creation and
954	 * destruction of events while we initialize event_waiters.
955	 */
956	mutex_lock(&p->event_mutex);
957
958	for (i = 0; i < num_events; i++) {
959		struct kfd_event_data event_data;
960
961		if (copy_from_user(&event_data, &events[i],
962				sizeof(struct kfd_event_data))) {
963			ret = -EFAULT;
964			goto out_unlock;
965		}
966
967		ret = init_event_waiter(p, &event_waiters[i], &event_data);
968		if (ret)
969			goto out_unlock;
970	}
971
972	/* Check condition once. */
973	*wait_result = test_event_condition(all, num_events, event_waiters);
974	if (*wait_result == KFD_IOC_WAIT_RESULT_COMPLETE) {
975		ret = copy_signaled_event_data(num_events,
976					       event_waiters, events);
977		goto out_unlock;
978	} else if (WARN_ON(*wait_result == KFD_IOC_WAIT_RESULT_FAIL)) {
979		/* This should not happen. Events shouldn't be
980		 * destroyed while we're holding the event_mutex
981		 */
982		goto out_unlock;
983	}
984
985	mutex_unlock(&p->event_mutex);
986
987	while (true) {
988		if (fatal_signal_pending(current)) {
989			ret = -EINTR;
990			break;
991		}
992
993		if (signal_pending(current)) {
994			ret = -ERESTARTSYS;
995			if (*user_timeout_ms != KFD_EVENT_TIMEOUT_IMMEDIATE &&
996			    *user_timeout_ms != KFD_EVENT_TIMEOUT_INFINITE)
997				*user_timeout_ms = jiffies_to_msecs(
998					max(0l, timeout-1));
999			break;
1000		}
1001
1002		/* Set task state to interruptible sleep before
1003		 * checking wake-up conditions. A concurrent wake-up
1004		 * will put the task back into runnable state. In that
1005		 * case schedule_timeout will not put the task to
1006		 * sleep and we'll get a chance to re-check the
1007		 * updated conditions almost immediately. Otherwise,
1008		 * this race condition would lead to a soft hang or a
1009		 * very long sleep.
1010		 */
1011		set_current_state(TASK_INTERRUPTIBLE);
1012
1013		*wait_result = test_event_condition(all, num_events,
1014						    event_waiters);
1015		if (*wait_result != KFD_IOC_WAIT_RESULT_TIMEOUT)
1016			break;
1017
1018		if (timeout <= 0)
1019			break;
1020
1021		timeout = schedule_timeout(timeout);
1022	}
1023	__set_current_state(TASK_RUNNING);
1024
1025	mutex_lock(&p->event_mutex);
1026	/* copy_signaled_event_data may sleep. So this has to happen
1027	 * after the task state is set back to RUNNING.
1028	 *
1029	 * The event may also have been destroyed after signaling. So
1030	 * copy_signaled_event_data also must confirm that the event
1031	 * still exists. Therefore this must be under the p->event_mutex
1032	 * which is also held when events are destroyed.
1033	 */
1034	if (!ret && *wait_result == KFD_IOC_WAIT_RESULT_COMPLETE)
1035		ret = copy_signaled_event_data(num_events,
1036					       event_waiters, events);
1037
1038out_unlock:
1039	free_waiters(num_events, event_waiters, ret == -ERESTARTSYS);
1040	mutex_unlock(&p->event_mutex);
1041out:
1042	if (ret)
1043		*wait_result = KFD_IOC_WAIT_RESULT_FAIL;
1044	else if (*wait_result == KFD_IOC_WAIT_RESULT_FAIL)
1045		ret = -EIO;
1046
1047	return ret;
1048}
1049
1050int kfd_event_mmap(struct kfd_process *p, struct vm_area_struct *vma)
1051{
1052	unsigned long pfn;
1053	struct kfd_signal_page *page;
1054	int ret;
1055
1056	/* check required size doesn't exceed the allocated size */
1057	if (get_order(KFD_SIGNAL_EVENT_LIMIT * 8) <
1058			get_order(vma->vm_end - vma->vm_start)) {
1059		pr_err("Event page mmap requested illegal size\n");
1060		return -EINVAL;
1061	}
1062
1063	page = p->signal_page;
1064	if (!page) {
1065		/* Probably KFD bug, but mmap is user-accessible. */
1066		pr_debug("Signal page could not be found\n");
1067		return -EINVAL;
1068	}
1069
1070	pfn = __pa(page->kernel_address);
1071	pfn >>= PAGE_SHIFT;
1072
1073	vm_flags_set(vma, VM_IO | VM_DONTCOPY | VM_DONTEXPAND | VM_NORESERVE
1074		       | VM_DONTDUMP | VM_PFNMAP);
1075
1076	pr_debug("Mapping signal page\n");
1077	pr_debug("     start user address  == 0x%08lx\n", vma->vm_start);
1078	pr_debug("     end user address    == 0x%08lx\n", vma->vm_end);
1079	pr_debug("     pfn                 == 0x%016lX\n", pfn);
1080	pr_debug("     vm_flags            == 0x%08lX\n", vma->vm_flags);
1081	pr_debug("     size                == 0x%08lX\n",
1082			vma->vm_end - vma->vm_start);
1083
1084	page->user_address = (uint64_t __user *)vma->vm_start;
1085
1086	/* mapping the page to user process */
1087	ret = remap_pfn_range(vma, vma->vm_start, pfn,
1088			vma->vm_end - vma->vm_start, vma->vm_page_prot);
1089	if (!ret)
1090		p->signal_mapped_size = vma->vm_end - vma->vm_start;
1091
1092	return ret;
1093}
1094
1095/*
1096 * Assumes that p is not going away.
1097 */
1098static void lookup_events_by_type_and_signal(struct kfd_process *p,
1099		int type, void *event_data)
1100{
1101	struct kfd_hsa_memory_exception_data *ev_data;
1102	struct kfd_event *ev;
1103	uint32_t id;
1104	bool send_signal = true;
1105
1106	ev_data = (struct kfd_hsa_memory_exception_data *) event_data;
1107
1108	rcu_read_lock();
1109
1110	id = KFD_FIRST_NONSIGNAL_EVENT_ID;
1111	idr_for_each_entry_continue(&p->event_idr, ev, id)
1112		if (ev->type == type) {
1113			send_signal = false;
1114			dev_dbg(kfd_device,
1115					"Event found: id %X type %d",
1116					ev->event_id, ev->type);
1117			spin_lock(&ev->lock);
1118			set_event(ev);
1119			if (ev->type == KFD_EVENT_TYPE_MEMORY && ev_data)
1120				ev->memory_exception_data = *ev_data;
1121			spin_unlock(&ev->lock);
1122		}
1123
1124	if (type == KFD_EVENT_TYPE_MEMORY) {
1125		dev_warn(kfd_device,
1126			"Sending SIGSEGV to process %d (pasid 0x%x)",
1127				p->lead_thread->pid, p->pasid);
1128		send_sig(SIGSEGV, p->lead_thread, 0);
1129	}
1130
1131	/* Send SIGTERM no event of type "type" has been found*/
1132	if (send_signal) {
1133		if (send_sigterm) {
1134			dev_warn(kfd_device,
1135				"Sending SIGTERM to process %d (pasid 0x%x)",
1136					p->lead_thread->pid, p->pasid);
1137			send_sig(SIGTERM, p->lead_thread, 0);
1138		} else {
1139			dev_err(kfd_device,
1140				"Process %d (pasid 0x%x) got unhandled exception",
1141				p->lead_thread->pid, p->pasid);
1142		}
1143	}
1144
1145	rcu_read_unlock();
1146}
1147
1148void kfd_signal_hw_exception_event(u32 pasid)
1149{
1150	/*
1151	 * Because we are called from arbitrary context (workqueue) as opposed
1152	 * to process context, kfd_process could attempt to exit while we are
1153	 * running so the lookup function increments the process ref count.
1154	 */
1155	struct kfd_process *p = kfd_lookup_process_by_pasid(pasid);
1156
1157	if (!p)
1158		return; /* Presumably process exited. */
1159
1160	lookup_events_by_type_and_signal(p, KFD_EVENT_TYPE_HW_EXCEPTION, NULL);
1161	kfd_unref_process(p);
1162}
1163
1164void kfd_signal_vm_fault_event(struct kfd_node *dev, u32 pasid,
1165				struct kfd_vm_fault_info *info,
1166				struct kfd_hsa_memory_exception_data *data)
1167{
1168	struct kfd_event *ev;
1169	uint32_t id;
1170	struct kfd_process *p = kfd_lookup_process_by_pasid(pasid);
1171	struct kfd_hsa_memory_exception_data memory_exception_data;
1172	int user_gpu_id;
1173
1174	if (!p)
1175		return; /* Presumably process exited. */
1176
1177	user_gpu_id = kfd_process_get_user_gpu_id(p, dev->id);
1178	if (unlikely(user_gpu_id == -EINVAL)) {
1179		WARN_ONCE(1, "Could not get user_gpu_id from dev->id:%x\n", dev->id);
1180		return;
1181	}
1182
1183	/* SoC15 chips and onwards will pass in data from now on. */
1184	if (!data) {
1185		memset(&memory_exception_data, 0, sizeof(memory_exception_data));
1186		memory_exception_data.gpu_id = user_gpu_id;
1187		memory_exception_data.failure.imprecise = true;
1188
1189		/* Set failure reason */
1190		if (info) {
1191			memory_exception_data.va = (info->page_addr) <<
1192								PAGE_SHIFT;
1193			memory_exception_data.failure.NotPresent =
1194				info->prot_valid ? 1 : 0;
1195			memory_exception_data.failure.NoExecute =
1196				info->prot_exec ? 1 : 0;
1197			memory_exception_data.failure.ReadOnly =
1198				info->prot_write ? 1 : 0;
1199			memory_exception_data.failure.imprecise = 0;
1200		}
1201	}
1202
1203	rcu_read_lock();
1204
1205	id = KFD_FIRST_NONSIGNAL_EVENT_ID;
1206	idr_for_each_entry_continue(&p->event_idr, ev, id)
1207		if (ev->type == KFD_EVENT_TYPE_MEMORY) {
1208			spin_lock(&ev->lock);
1209			ev->memory_exception_data = data ? *data :
1210							memory_exception_data;
1211			set_event(ev);
1212			spin_unlock(&ev->lock);
1213		}
1214
1215	rcu_read_unlock();
1216	kfd_unref_process(p);
1217}
1218
1219void kfd_signal_reset_event(struct kfd_node *dev)
1220{
1221	struct kfd_hsa_hw_exception_data hw_exception_data;
1222	struct kfd_hsa_memory_exception_data memory_exception_data;
1223	struct kfd_process *p;
1224	struct kfd_event *ev;
1225	unsigned int temp;
1226	uint32_t id, idx;
1227	int reset_cause = atomic_read(&dev->sram_ecc_flag) ?
1228			KFD_HW_EXCEPTION_ECC :
1229			KFD_HW_EXCEPTION_GPU_HANG;
1230
1231	/* Whole gpu reset caused by GPU hang and memory is lost */
1232	memset(&hw_exception_data, 0, sizeof(hw_exception_data));
1233	hw_exception_data.memory_lost = 1;
1234	hw_exception_data.reset_cause = reset_cause;
1235
1236	memset(&memory_exception_data, 0, sizeof(memory_exception_data));
1237	memory_exception_data.ErrorType = KFD_MEM_ERR_SRAM_ECC;
1238	memory_exception_data.failure.imprecise = true;
1239
1240	idx = srcu_read_lock(&kfd_processes_srcu);
1241	hash_for_each_rcu(kfd_processes_table, temp, p, kfd_processes) {
1242		int user_gpu_id = kfd_process_get_user_gpu_id(p, dev->id);
1243
1244		if (unlikely(user_gpu_id == -EINVAL)) {
1245			WARN_ONCE(1, "Could not get user_gpu_id from dev->id:%x\n", dev->id);
1246			continue;
1247		}
1248
1249		rcu_read_lock();
1250
1251		id = KFD_FIRST_NONSIGNAL_EVENT_ID;
1252		idr_for_each_entry_continue(&p->event_idr, ev, id) {
1253			if (ev->type == KFD_EVENT_TYPE_HW_EXCEPTION) {
1254				spin_lock(&ev->lock);
1255				ev->hw_exception_data = hw_exception_data;
1256				ev->hw_exception_data.gpu_id = user_gpu_id;
1257				set_event(ev);
1258				spin_unlock(&ev->lock);
1259			}
1260			if (ev->type == KFD_EVENT_TYPE_MEMORY &&
1261			    reset_cause == KFD_HW_EXCEPTION_ECC) {
1262				spin_lock(&ev->lock);
1263				ev->memory_exception_data = memory_exception_data;
1264				ev->memory_exception_data.gpu_id = user_gpu_id;
1265				set_event(ev);
1266				spin_unlock(&ev->lock);
1267			}
1268		}
1269
1270		rcu_read_unlock();
1271	}
1272	srcu_read_unlock(&kfd_processes_srcu, idx);
1273}
1274
1275void kfd_signal_poison_consumed_event(struct kfd_node *dev, u32 pasid)
1276{
1277	struct kfd_process *p = kfd_lookup_process_by_pasid(pasid);
1278	struct kfd_hsa_memory_exception_data memory_exception_data;
1279	struct kfd_hsa_hw_exception_data hw_exception_data;
1280	struct kfd_event *ev;
1281	uint32_t id = KFD_FIRST_NONSIGNAL_EVENT_ID;
1282	int user_gpu_id;
1283
1284	if (!p)
1285		return; /* Presumably process exited. */
1286
1287	user_gpu_id = kfd_process_get_user_gpu_id(p, dev->id);
1288	if (unlikely(user_gpu_id == -EINVAL)) {
1289		WARN_ONCE(1, "Could not get user_gpu_id from dev->id:%x\n", dev->id);
1290		return;
1291	}
1292
1293	memset(&hw_exception_data, 0, sizeof(hw_exception_data));
1294	hw_exception_data.gpu_id = user_gpu_id;
1295	hw_exception_data.memory_lost = 1;
1296	hw_exception_data.reset_cause = KFD_HW_EXCEPTION_ECC;
1297
1298	memset(&memory_exception_data, 0, sizeof(memory_exception_data));
1299	memory_exception_data.ErrorType = KFD_MEM_ERR_POISON_CONSUMED;
1300	memory_exception_data.gpu_id = user_gpu_id;
1301	memory_exception_data.failure.imprecise = true;
1302
1303	rcu_read_lock();
1304
1305	idr_for_each_entry_continue(&p->event_idr, ev, id) {
1306		if (ev->type == KFD_EVENT_TYPE_HW_EXCEPTION) {
1307			spin_lock(&ev->lock);
1308			ev->hw_exception_data = hw_exception_data;
1309			set_event(ev);
1310			spin_unlock(&ev->lock);
1311		}
1312
1313		if (ev->type == KFD_EVENT_TYPE_MEMORY) {
1314			spin_lock(&ev->lock);
1315			ev->memory_exception_data = memory_exception_data;
1316			set_event(ev);
1317			spin_unlock(&ev->lock);
1318		}
1319	}
1320
1321	rcu_read_unlock();
1322
1323	/* user application will handle SIGBUS signal */
1324	send_sig(SIGBUS, p->lead_thread, 0);
1325
1326	kfd_unref_process(p);
1327}
1328