1/*
2 * Copyright 2014 Advanced Micro Devices, Inc.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20 * OTHER DEALINGS IN THE SOFTWARE.
21 */
22
23#include <linux/mm_types.h>
24#include <linux/slab.h>
25#include <linux/types.h>
26#include <linux/sched.h>
27#include <linux/uaccess.h>
28#include <linux/mm.h>
29#include <linux/mman.h>
30#include <linux/memory.h>
31#include "kfd_priv.h"
32#include "kfd_events.h"
33#include <linux/device.h>
34
35/*
36 * A task can only be on a single wait_queue at a time, but we need to support
37 * waiting on multiple events (any/all).
38 * Instead of each event simply having a wait_queue with sleeping tasks, it
39 * has a singly-linked list of tasks.
40 * A thread that wants to sleep creates an array of these, one for each event
41 * and adds one to each event's waiter chain.
42 */
43struct kfd_event_waiter {
44	struct list_head waiters;
45	struct task_struct *sleeping_task;
46
47	/* Transitions to true when the event this belongs to is signaled. */
48	bool activated;
49
50	/* Event */
51	struct kfd_event *event;
52	uint32_t input_index;
53};
54
55/*
56 * Over-complicated pooled allocator for event notification slots.
57 *
58 * Each signal event needs a 64-bit signal slot where the signaler will write
59 * a 1 before sending an interrupt.l (This is needed because some interrupts
60 * do not contain enough spare data bits to identify an event.)
61 * We get whole pages from vmalloc and map them to the process VA.
62 * Individual signal events are then allocated a slot in a page.
63 */
64
65struct signal_page {
66	struct list_head event_pages;	/* kfd_process.signal_event_pages */
67	uint64_t *kernel_address;
68	uint64_t __user *user_address;
69	uint32_t page_index;		/* Index into the mmap aperture. */
70	unsigned int free_slots;
71	unsigned long used_slot_bitmap[0];
72};
73
74#define SLOTS_PER_PAGE KFD_SIGNAL_EVENT_LIMIT
75#define SLOT_BITMAP_SIZE BITS_TO_LONGS(SLOTS_PER_PAGE)
76#define BITS_PER_PAGE (ilog2(SLOTS_PER_PAGE)+1)
77#define SIGNAL_PAGE_SIZE (sizeof(struct signal_page) + \
78				SLOT_BITMAP_SIZE * sizeof(long))
79
80/*
81 * For signal events, the event ID is used as the interrupt user data.
82 * For SQ s_sendmsg interrupts, this is limited to 8 bits.
83 */
84
85#define INTERRUPT_DATA_BITS 8
86#define SIGNAL_EVENT_ID_SLOT_SHIFT 0
87
88static uint64_t *page_slots(struct signal_page *page)
89{
90	return page->kernel_address;
91}
92
93static bool allocate_free_slot(struct kfd_process *process,
94				struct signal_page **out_page,
95				unsigned int *out_slot_index)
96{
97	struct signal_page *page;
98
99	list_for_each_entry(page, &process->signal_event_pages, event_pages) {
100		if (page->free_slots > 0) {
101			unsigned int slot =
102				find_first_zero_bit(page->used_slot_bitmap,
103							SLOTS_PER_PAGE);
104
105			__set_bit(slot, page->used_slot_bitmap);
106			page->free_slots--;
107
108			page_slots(page)[slot] = UNSIGNALED_EVENT_SLOT;
109
110			*out_page = page;
111			*out_slot_index = slot;
112
113			pr_debug("allocated event signal slot in page %p, slot %d\n",
114					page, slot);
115
116			return true;
117		}
118	}
119
120	pr_debug("No free event signal slots were found for process %p\n",
121			process);
122
123	return false;
124}
125
126#define list_tail_entry(head, type, member) \
127	list_entry((head)->prev, type, member)
128
129static bool allocate_signal_page(struct file *devkfd, struct kfd_process *p)
130{
131	void *backing_store;
132	struct signal_page *page;
133
134	page = kzalloc(SIGNAL_PAGE_SIZE, GFP_KERNEL);
135	if (!page)
136		goto fail_alloc_signal_page;
137
138	page->free_slots = SLOTS_PER_PAGE;
139
140	backing_store = (void *) __get_free_pages(GFP_KERNEL | __GFP_ZERO,
141					get_order(KFD_SIGNAL_EVENT_LIMIT * 8));
142	if (!backing_store)
143		goto fail_alloc_signal_store;
144
145	/* prevent user-mode info leaks */
146	memset(backing_store, (uint8_t) UNSIGNALED_EVENT_SLOT,
147		KFD_SIGNAL_EVENT_LIMIT * 8);
148
149	page->kernel_address = backing_store;
150
151	if (list_empty(&p->signal_event_pages))
152		page->page_index = 0;
153	else
154		page->page_index = list_tail_entry(&p->signal_event_pages,
155						   struct signal_page,
156						   event_pages)->page_index + 1;
157
158	pr_debug("allocated new event signal page at %p, for process %p\n",
159			page, p);
160	pr_debug("page index is %d\n", page->page_index);
161
162	list_add(&page->event_pages, &p->signal_event_pages);
163
164	return true;
165
166fail_alloc_signal_store:
167	kfree(page);
168fail_alloc_signal_page:
169	return false;
170}
171
172static bool allocate_event_notification_slot(struct file *devkfd,
173					struct kfd_process *p,
174					struct signal_page **page,
175					unsigned int *signal_slot_index)
176{
177	bool ret;
178
179	ret = allocate_free_slot(p, page, signal_slot_index);
180	if (ret == false) {
181		ret = allocate_signal_page(devkfd, p);
182		if (ret == true)
183			ret = allocate_free_slot(p, page, signal_slot_index);
184	}
185
186	return ret;
187}
188
189/* Assumes that the process's event_mutex is locked. */
190static void release_event_notification_slot(struct signal_page *page,
191						size_t slot_index)
192{
193	__clear_bit(slot_index, page->used_slot_bitmap);
194	page->free_slots++;
195
196	/* We don't free signal pages, they are retained by the process
197	 * and reused until it exits. */
198}
199
200static struct signal_page *lookup_signal_page_by_index(struct kfd_process *p,
201						unsigned int page_index)
202{
203	struct signal_page *page;
204
205	/*
206	 * This is safe because we don't delete signal pages until the
207	 * process exits.
208	 */
209	list_for_each_entry(page, &p->signal_event_pages, event_pages)
210		if (page->page_index == page_index)
211			return page;
212
213	return NULL;
214}
215
216/*
217 * Assumes that p->event_mutex is held and of course that p is not going
218 * away (current or locked).
219 */
220static struct kfd_event *lookup_event_by_id(struct kfd_process *p, uint32_t id)
221{
222	struct kfd_event *ev;
223
224	hash_for_each_possible(p->events, ev, events, id)
225		if (ev->event_id == id)
226			return ev;
227
228	return NULL;
229}
230
231static u32 make_signal_event_id(struct signal_page *page,
232					 unsigned int signal_slot_index)
233{
234	return page->page_index |
235			(signal_slot_index << SIGNAL_EVENT_ID_SLOT_SHIFT);
236}
237
238/*
239 * Produce a kfd event id for a nonsignal event.
240 * These are arbitrary numbers, so we do a sequential search through
241 * the hash table for an unused number.
242 */
243static u32 make_nonsignal_event_id(struct kfd_process *p)
244{
245	u32 id;
246
247	for (id = p->next_nonsignal_event_id;
248		id < KFD_LAST_NONSIGNAL_EVENT_ID &&
249		lookup_event_by_id(p, id) != NULL;
250		id++)
251		;
252
253	if (id < KFD_LAST_NONSIGNAL_EVENT_ID) {
254
255		/*
256		 * What if id == LAST_NONSIGNAL_EVENT_ID - 1?
257		 * Then next_nonsignal_event_id = LAST_NONSIGNAL_EVENT_ID so
258		 * the first loop fails immediately and we proceed with the
259		 * wraparound loop below.
260		 */
261		p->next_nonsignal_event_id = id + 1;
262
263		return id;
264	}
265
266	for (id = KFD_FIRST_NONSIGNAL_EVENT_ID;
267		id < KFD_LAST_NONSIGNAL_EVENT_ID &&
268		lookup_event_by_id(p, id) != NULL;
269		id++)
270		;
271
272
273	if (id < KFD_LAST_NONSIGNAL_EVENT_ID) {
274		p->next_nonsignal_event_id = id + 1;
275		return id;
276	}
277
278	p->next_nonsignal_event_id = KFD_FIRST_NONSIGNAL_EVENT_ID;
279	return 0;
280}
281
282static struct kfd_event *lookup_event_by_page_slot(struct kfd_process *p,
283						struct signal_page *page,
284						unsigned int signal_slot)
285{
286	return lookup_event_by_id(p, make_signal_event_id(page, signal_slot));
287}
288
289static int create_signal_event(struct file *devkfd,
290				struct kfd_process *p,
291				struct kfd_event *ev)
292{
293	if (p->signal_event_count == KFD_SIGNAL_EVENT_LIMIT) {
294		pr_warn("amdkfd: Signal event wasn't created because limit was reached\n");
295		return -ENOMEM;
296	}
297
298	if (!allocate_event_notification_slot(devkfd, p, &ev->signal_page,
299						&ev->signal_slot_index)) {
300		pr_warn("amdkfd: Signal event wasn't created because out of kernel memory\n");
301		return -ENOMEM;
302	}
303
304	p->signal_event_count++;
305
306	ev->user_signal_address =
307			&ev->signal_page->user_address[ev->signal_slot_index];
308
309	ev->event_id = make_signal_event_id(ev->signal_page,
310						ev->signal_slot_index);
311
312	pr_debug("signal event number %zu created with id %d, address %p\n",
313			p->signal_event_count, ev->event_id,
314			ev->user_signal_address);
315
316	pr_debug("signal event number %zu created with id %d, address %p\n",
317			p->signal_event_count, ev->event_id,
318			ev->user_signal_address);
319
320	return 0;
321}
322
323/*
324 * No non-signal events are supported yet.
325 * We create them as events that never signal.
326 * Set event calls from user-mode are failed.
327 */
328static int create_other_event(struct kfd_process *p, struct kfd_event *ev)
329{
330	ev->event_id = make_nonsignal_event_id(p);
331	if (ev->event_id == 0)
332		return -ENOMEM;
333
334	return 0;
335}
336
337void kfd_event_init_process(struct kfd_process *p)
338{
339	mutex_init(&p->event_mutex);
340	hash_init(p->events);
341	INIT_LIST_HEAD(&p->signal_event_pages);
342	p->next_nonsignal_event_id = KFD_FIRST_NONSIGNAL_EVENT_ID;
343	p->signal_event_count = 0;
344}
345
346static void destroy_event(struct kfd_process *p, struct kfd_event *ev)
347{
348	if (ev->signal_page != NULL) {
349		release_event_notification_slot(ev->signal_page,
350						ev->signal_slot_index);
351		p->signal_event_count--;
352	}
353
354	/*
355	 * Abandon the list of waiters. Individual waiting threads will
356	 * clean up their own data.
357	 */
358	list_del(&ev->waiters);
359
360	hash_del(&ev->events);
361	kfree(ev);
362}
363
364static void destroy_events(struct kfd_process *p)
365{
366	struct kfd_event *ev;
367	struct hlist_node *tmp;
368	unsigned int hash_bkt;
369
370	hash_for_each_safe(p->events, hash_bkt, tmp, ev, events)
371		destroy_event(p, ev);
372}
373
374/*
375 * We assume that the process is being destroyed and there is no need to
376 * unmap the pages or keep bookkeeping data in order.
377 */
378static void shutdown_signal_pages(struct kfd_process *p)
379{
380	struct signal_page *page, *tmp;
381
382	list_for_each_entry_safe(page, tmp, &p->signal_event_pages,
383					event_pages) {
384		free_pages((unsigned long)page->kernel_address,
385				get_order(KFD_SIGNAL_EVENT_LIMIT * 8));
386		kfree(page);
387	}
388}
389
390void kfd_event_free_process(struct kfd_process *p)
391{
392	destroy_events(p);
393	shutdown_signal_pages(p);
394}
395
396static bool event_can_be_gpu_signaled(const struct kfd_event *ev)
397{
398	return ev->type == KFD_EVENT_TYPE_SIGNAL ||
399					ev->type == KFD_EVENT_TYPE_DEBUG;
400}
401
402static bool event_can_be_cpu_signaled(const struct kfd_event *ev)
403{
404	return ev->type == KFD_EVENT_TYPE_SIGNAL;
405}
406
407int kfd_event_create(struct file *devkfd, struct kfd_process *p,
408		     uint32_t event_type, bool auto_reset, uint32_t node_id,
409		     uint32_t *event_id, uint32_t *event_trigger_data,
410		     uint64_t *event_page_offset, uint32_t *event_slot_index)
411{
412	int ret = 0;
413	struct kfd_event *ev = kzalloc(sizeof(*ev), GFP_KERNEL);
414
415	if (!ev)
416		return -ENOMEM;
417
418	ev->type = event_type;
419	ev->auto_reset = auto_reset;
420	ev->signaled = false;
421
422	INIT_LIST_HEAD(&ev->waiters);
423
424	*event_page_offset = 0;
425
426	mutex_lock(&p->event_mutex);
427
428	switch (event_type) {
429	case KFD_EVENT_TYPE_SIGNAL:
430	case KFD_EVENT_TYPE_DEBUG:
431		ret = create_signal_event(devkfd, p, ev);
432		if (!ret) {
433			*event_page_offset = (ev->signal_page->page_index |
434					KFD_MMAP_EVENTS_MASK);
435			*event_page_offset <<= PAGE_SHIFT;
436			*event_slot_index = ev->signal_slot_index;
437		}
438		break;
439	default:
440		ret = create_other_event(p, ev);
441		break;
442	}
443
444	if (!ret) {
445		hash_add(p->events, &ev->events, ev->event_id);
446
447		*event_id = ev->event_id;
448		*event_trigger_data = ev->event_id;
449	} else {
450		kfree(ev);
451	}
452
453	mutex_unlock(&p->event_mutex);
454
455	return ret;
456}
457
458/* Assumes that p is current. */
459int kfd_event_destroy(struct kfd_process *p, uint32_t event_id)
460{
461	struct kfd_event *ev;
462	int ret = 0;
463
464	mutex_lock(&p->event_mutex);
465
466	ev = lookup_event_by_id(p, event_id);
467
468	if (ev)
469		destroy_event(p, ev);
470	else
471		ret = -EINVAL;
472
473	mutex_unlock(&p->event_mutex);
474	return ret;
475}
476
477static void set_event(struct kfd_event *ev)
478{
479	struct kfd_event_waiter *waiter;
480	struct kfd_event_waiter *next;
481
482	/* Auto reset if the list is non-empty and we're waking someone. */
483	ev->signaled = !ev->auto_reset || list_empty(&ev->waiters);
484
485	list_for_each_entry_safe(waiter, next, &ev->waiters, waiters) {
486		waiter->activated = true;
487
488		/* _init because free_waiters will call list_del */
489		list_del_init(&waiter->waiters);
490
491		wake_up_process(waiter->sleeping_task);
492	}
493}
494
495/* Assumes that p is current. */
496int kfd_set_event(struct kfd_process *p, uint32_t event_id)
497{
498	int ret = 0;
499	struct kfd_event *ev;
500
501	mutex_lock(&p->event_mutex);
502
503	ev = lookup_event_by_id(p, event_id);
504
505	if (ev && event_can_be_cpu_signaled(ev))
506		set_event(ev);
507	else
508		ret = -EINVAL;
509
510	mutex_unlock(&p->event_mutex);
511	return ret;
512}
513
514static void reset_event(struct kfd_event *ev)
515{
516	ev->signaled = false;
517}
518
519/* Assumes that p is current. */
520int kfd_reset_event(struct kfd_process *p, uint32_t event_id)
521{
522	int ret = 0;
523	struct kfd_event *ev;
524
525	mutex_lock(&p->event_mutex);
526
527	ev = lookup_event_by_id(p, event_id);
528
529	if (ev && event_can_be_cpu_signaled(ev))
530		reset_event(ev);
531	else
532		ret = -EINVAL;
533
534	mutex_unlock(&p->event_mutex);
535	return ret;
536
537}
538
539static void acknowledge_signal(struct kfd_process *p, struct kfd_event *ev)
540{
541	page_slots(ev->signal_page)[ev->signal_slot_index] =
542						UNSIGNALED_EVENT_SLOT;
543}
544
545static bool is_slot_signaled(struct signal_page *page, unsigned int index)
546{
547	return page_slots(page)[index] != UNSIGNALED_EVENT_SLOT;
548}
549
550static void set_event_from_interrupt(struct kfd_process *p,
551					struct kfd_event *ev)
552{
553	if (ev && event_can_be_gpu_signaled(ev)) {
554		acknowledge_signal(p, ev);
555		set_event(ev);
556	}
557}
558
559void kfd_signal_event_interrupt(unsigned int pasid, uint32_t partial_id,
560				uint32_t valid_id_bits)
561{
562	struct kfd_event *ev;
563
564	/*
565	 * Because we are called from arbitrary context (workqueue) as opposed
566	 * to process context, kfd_process could attempt to exit while we are
567	 * running so the lookup function returns a locked process.
568	 */
569	struct kfd_process *p = kfd_lookup_process_by_pasid(pasid);
570
571	if (!p)
572		return; /* Presumably process exited. */
573
574	mutex_lock(&p->event_mutex);
575
576	if (valid_id_bits >= INTERRUPT_DATA_BITS) {
577		/* Partial ID is a full ID. */
578		ev = lookup_event_by_id(p, partial_id);
579		set_event_from_interrupt(p, ev);
580	} else {
581		/*
582		 * Partial ID is in fact partial. For now we completely
583		 * ignore it, but we could use any bits we did receive to
584		 * search faster.
585		 */
586		struct signal_page *page;
587		unsigned i;
588
589		list_for_each_entry(page, &p->signal_event_pages, event_pages)
590			for (i = 0; i < SLOTS_PER_PAGE; i++)
591				if (is_slot_signaled(page, i)) {
592					ev = lookup_event_by_page_slot(p,
593								page, i);
594					set_event_from_interrupt(p, ev);
595				}
596	}
597
598	mutex_unlock(&p->event_mutex);
599	mutex_unlock(&p->mutex);
600}
601
602static struct kfd_event_waiter *alloc_event_waiters(uint32_t num_events)
603{
604	struct kfd_event_waiter *event_waiters;
605	uint32_t i;
606
607	event_waiters = kmalloc_array(num_events,
608					sizeof(struct kfd_event_waiter),
609					GFP_KERNEL);
610
611	for (i = 0; (event_waiters) && (i < num_events) ; i++) {
612		INIT_LIST_HEAD(&event_waiters[i].waiters);
613		event_waiters[i].sleeping_task = current;
614		event_waiters[i].activated = false;
615	}
616
617	return event_waiters;
618}
619
620static int init_event_waiter(struct kfd_process *p,
621		struct kfd_event_waiter *waiter,
622		uint32_t event_id,
623		uint32_t input_index)
624{
625	struct kfd_event *ev = lookup_event_by_id(p, event_id);
626
627	if (!ev)
628		return -EINVAL;
629
630	waiter->event = ev;
631	waiter->input_index = input_index;
632	waiter->activated = ev->signaled;
633	ev->signaled = ev->signaled && !ev->auto_reset;
634
635	list_add(&waiter->waiters, &ev->waiters);
636
637	return 0;
638}
639
640static bool test_event_condition(bool all, uint32_t num_events,
641				struct kfd_event_waiter *event_waiters)
642{
643	uint32_t i;
644	uint32_t activated_count = 0;
645
646	for (i = 0; i < num_events; i++) {
647		if (event_waiters[i].activated) {
648			if (!all)
649				return true;
650
651			activated_count++;
652		}
653	}
654
655	return activated_count == num_events;
656}
657
658/*
659 * Copy event specific data, if defined.
660 * Currently only memory exception events have additional data to copy to user
661 */
662static bool copy_signaled_event_data(uint32_t num_events,
663		struct kfd_event_waiter *event_waiters,
664		struct kfd_event_data __user *data)
665{
666	struct kfd_hsa_memory_exception_data *src;
667	struct kfd_hsa_memory_exception_data __user *dst;
668	struct kfd_event_waiter *waiter;
669	struct kfd_event *event;
670	uint32_t i;
671
672	for (i = 0; i < num_events; i++) {
673		waiter = &event_waiters[i];
674		event = waiter->event;
675		if (waiter->activated && event->type == KFD_EVENT_TYPE_MEMORY) {
676			dst = &data[waiter->input_index].memory_exception_data;
677			src = &event->memory_exception_data;
678			if (copy_to_user(dst, src,
679				sizeof(struct kfd_hsa_memory_exception_data)))
680				return false;
681		}
682	}
683
684	return true;
685
686}
687
688
689
690static long user_timeout_to_jiffies(uint32_t user_timeout_ms)
691{
692	if (user_timeout_ms == KFD_EVENT_TIMEOUT_IMMEDIATE)
693		return 0;
694
695	if (user_timeout_ms == KFD_EVENT_TIMEOUT_INFINITE)
696		return MAX_SCHEDULE_TIMEOUT;
697
698	/*
699	 * msecs_to_jiffies interprets all values above 2^31-1 as infinite,
700	 * but we consider them finite.
701	 * This hack is wrong, but nobody is likely to notice.
702	 */
703	user_timeout_ms = min_t(uint32_t, user_timeout_ms, 0x7FFFFFFF);
704
705	return msecs_to_jiffies(user_timeout_ms) + 1;
706}
707
708static void free_waiters(uint32_t num_events, struct kfd_event_waiter *waiters)
709{
710	uint32_t i;
711
712	for (i = 0; i < num_events; i++)
713		list_del(&waiters[i].waiters);
714
715	kfree(waiters);
716}
717
718int kfd_wait_on_events(struct kfd_process *p,
719		       uint32_t num_events, void __user *data,
720		       bool all, uint32_t user_timeout_ms,
721		       enum kfd_event_wait_result *wait_result)
722{
723	struct kfd_event_data __user *events =
724			(struct kfd_event_data __user *) data;
725	uint32_t i;
726	int ret = 0;
727	struct kfd_event_waiter *event_waiters = NULL;
728	long timeout = user_timeout_to_jiffies(user_timeout_ms);
729
730	mutex_lock(&p->event_mutex);
731
732	event_waiters = alloc_event_waiters(num_events);
733	if (!event_waiters) {
734		ret = -ENOMEM;
735		goto fail;
736	}
737
738	for (i = 0; i < num_events; i++) {
739		struct kfd_event_data event_data;
740
741		if (copy_from_user(&event_data, &events[i],
742				sizeof(struct kfd_event_data)))
743			goto fail;
744
745		ret = init_event_waiter(p, &event_waiters[i],
746				event_data.event_id, i);
747		if (ret)
748			goto fail;
749	}
750
751	mutex_unlock(&p->event_mutex);
752
753	while (true) {
754		if (fatal_signal_pending(current)) {
755			ret = -EINTR;
756			break;
757		}
758
759		if (signal_pending(current)) {
760			/*
761			 * This is wrong when a nonzero, non-infinite timeout
762			 * is specified. We need to use
763			 * ERESTARTSYS_RESTARTBLOCK, but struct restart_block
764			 * contains a union with data for each user and it's
765			 * in generic kernel code that I don't want to
766			 * touch yet.
767			 */
768			ret = -ERESTARTSYS;
769			break;
770		}
771
772		if (test_event_condition(all, num_events, event_waiters)) {
773			if (copy_signaled_event_data(num_events,
774					event_waiters, events))
775				*wait_result = KFD_WAIT_COMPLETE;
776			else
777				*wait_result = KFD_WAIT_ERROR;
778			break;
779		}
780
781		if (timeout <= 0) {
782			*wait_result = KFD_WAIT_TIMEOUT;
783			break;
784		}
785
786		timeout = schedule_timeout_interruptible(timeout);
787	}
788	__set_current_state(TASK_RUNNING);
789
790	mutex_lock(&p->event_mutex);
791	free_waiters(num_events, event_waiters);
792	mutex_unlock(&p->event_mutex);
793
794	return ret;
795
796fail:
797	if (event_waiters)
798		free_waiters(num_events, event_waiters);
799
800	mutex_unlock(&p->event_mutex);
801
802	*wait_result = KFD_WAIT_ERROR;
803
804	return ret;
805}
806
807int kfd_event_mmap(struct kfd_process *p, struct vm_area_struct *vma)
808{
809
810	unsigned int page_index;
811	unsigned long pfn;
812	struct signal_page *page;
813
814	/* check required size is logical */
815	if (get_order(KFD_SIGNAL_EVENT_LIMIT * 8) !=
816			get_order(vma->vm_end - vma->vm_start)) {
817		pr_err("amdkfd: event page mmap requested illegal size\n");
818		return -EINVAL;
819	}
820
821	page_index = vma->vm_pgoff;
822
823	page = lookup_signal_page_by_index(p, page_index);
824	if (!page) {
825		/* Probably KFD bug, but mmap is user-accessible. */
826		pr_debug("signal page could not be found for page_index %u\n",
827				page_index);
828		return -EINVAL;
829	}
830
831	pfn = __pa(page->kernel_address);
832	pfn >>= PAGE_SHIFT;
833
834	vma->vm_flags |= VM_IO | VM_DONTCOPY | VM_DONTEXPAND | VM_NORESERVE
835		       | VM_DONTDUMP | VM_PFNMAP;
836
837	pr_debug("mapping signal page\n");
838	pr_debug("     start user address  == 0x%08lx\n", vma->vm_start);
839	pr_debug("     end user address    == 0x%08lx\n", vma->vm_end);
840	pr_debug("     pfn                 == 0x%016lX\n", pfn);
841	pr_debug("     vm_flags            == 0x%08lX\n", vma->vm_flags);
842	pr_debug("     size                == 0x%08lX\n",
843			vma->vm_end - vma->vm_start);
844
845	page->user_address = (uint64_t __user *)vma->vm_start;
846
847	/* mapping the page to user process */
848	return remap_pfn_range(vma, vma->vm_start, pfn,
849			vma->vm_end - vma->vm_start, vma->vm_page_prot);
850}
851
852/*
853 * Assumes that p->event_mutex is held and of course
854 * that p is not going away (current or locked).
855 */
856static void lookup_events_by_type_and_signal(struct kfd_process *p,
857		int type, void *event_data)
858{
859	struct kfd_hsa_memory_exception_data *ev_data;
860	struct kfd_event *ev;
861	int bkt;
862	bool send_signal = true;
863
864	ev_data = (struct kfd_hsa_memory_exception_data *) event_data;
865
866	hash_for_each(p->events, bkt, ev, events)
867		if (ev->type == type) {
868			send_signal = false;
869			dev_dbg(kfd_device,
870					"Event found: id %X type %d",
871					ev->event_id, ev->type);
872			set_event(ev);
873			if (ev->type == KFD_EVENT_TYPE_MEMORY && ev_data)
874				ev->memory_exception_data = *ev_data;
875		}
876
877	/* Send SIGTERM no event of type "type" has been found*/
878	if (send_signal) {
879		if (send_sigterm) {
880			dev_warn(kfd_device,
881				"Sending SIGTERM to HSA Process with PID %d ",
882					p->lead_thread->pid);
883			send_sig(SIGTERM, p->lead_thread, 0);
884		} else {
885			dev_err(kfd_device,
886				"HSA Process (PID %d) got unhandled exception",
887				p->lead_thread->pid);
888		}
889	}
890}
891
892void kfd_signal_iommu_event(struct kfd_dev *dev, unsigned int pasid,
893		unsigned long address, bool is_write_requested,
894		bool is_execute_requested)
895{
896	struct kfd_hsa_memory_exception_data memory_exception_data;
897	struct vm_area_struct *vma;
898
899	/*
900	 * Because we are called from arbitrary context (workqueue) as opposed
901	 * to process context, kfd_process could attempt to exit while we are
902	 * running so the lookup function returns a locked process.
903	 */
904	struct kfd_process *p = kfd_lookup_process_by_pasid(pasid);
905
906	if (!p)
907		return; /* Presumably process exited. */
908
909	memset(&memory_exception_data, 0, sizeof(memory_exception_data));
910
911	down_read(&p->mm->mmap_sem);
912	vma = find_vma(p->mm, address);
913
914	memory_exception_data.gpu_id = dev->id;
915	memory_exception_data.va = address;
916	/* Set failure reason */
917	memory_exception_data.failure.NotPresent = 1;
918	memory_exception_data.failure.NoExecute = 0;
919	memory_exception_data.failure.ReadOnly = 0;
920	if (vma) {
921		if (vma->vm_start > address) {
922			memory_exception_data.failure.NotPresent = 1;
923			memory_exception_data.failure.NoExecute = 0;
924			memory_exception_data.failure.ReadOnly = 0;
925		} else {
926			memory_exception_data.failure.NotPresent = 0;
927			if (is_write_requested && !(vma->vm_flags & VM_WRITE))
928				memory_exception_data.failure.ReadOnly = 1;
929			else
930				memory_exception_data.failure.ReadOnly = 0;
931			if (is_execute_requested && !(vma->vm_flags & VM_EXEC))
932				memory_exception_data.failure.NoExecute = 1;
933			else
934				memory_exception_data.failure.NoExecute = 0;
935		}
936	}
937
938	up_read(&p->mm->mmap_sem);
939
940	mutex_lock(&p->event_mutex);
941
942	/* Lookup events by type and signal them */
943	lookup_events_by_type_and_signal(p, KFD_EVENT_TYPE_MEMORY,
944			&memory_exception_data);
945
946	mutex_unlock(&p->event_mutex);
947	mutex_unlock(&p->mutex);
948}
949
950void kfd_signal_hw_exception_event(unsigned int pasid)
951{
952	/*
953	 * Because we are called from arbitrary context (workqueue) as opposed
954	 * to process context, kfd_process could attempt to exit while we are
955	 * running so the lookup function returns a locked process.
956	 */
957	struct kfd_process *p = kfd_lookup_process_by_pasid(pasid);
958
959	if (!p)
960		return; /* Presumably process exited. */
961
962	mutex_lock(&p->event_mutex);
963
964	/* Lookup events by type and signal them */
965	lookup_events_by_type_and_signal(p, KFD_EVENT_TYPE_HW_EXCEPTION, NULL);
966
967	mutex_unlock(&p->event_mutex);
968	mutex_unlock(&p->mutex);
969}
970