summaryrefslogtreecommitdiff
path: root/drivers/gpu/drm/ttm/ttm_execbuf_util.c
blob: 957ec375a4ba54b5399c89aa5dda91ae822e9abd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
/* SPDX-License-Identifier: GPL-2.0 OR MIT */
/**************************************************************************
 *
 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 * USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 **************************************************************************/

#include <drm/ttm/ttm_execbuf_util.h>
#include <drm/ttm/ttm_bo_driver.h>
#include <drm/ttm/ttm_placement.h>
#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/module.h>

static void ttm_eu_backoff_reservation_reverse(struct list_head *list,
					      struct ttm_validate_buffer *entry)
{
	list_for_each_entry_continue_reverse(entry, list, head) {
		struct ttm_buffer_object *bo = entry->bo;

		reservation_object_unlock(bo->resv);
	}
}

static void ttm_eu_del_from_lru_locked(struct list_head *list)
{
	struct ttm_validate_buffer *entry;

	list_for_each_entry(entry, list, head) {
		struct ttm_buffer_object *bo = entry->bo;
		ttm_bo_del_from_lru(bo);
	}
}

void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket,
				struct list_head *list)
{
	struct ttm_validate_buffer *entry;
	struct ttm_bo_global *glob;

	if (list_empty(list))
		return;

	entry = list_first_entry(list, struct ttm_validate_buffer, head);
	glob = entry->bo->bdev->glob;

	spin_lock(&glob->lru_lock);
	list_for_each_entry(entry, list, head) {
		struct ttm_buffer_object *bo = entry->bo;

		if (list_empty(&bo->lru))
			ttm_bo_add_to_lru(bo);
		reservation_object_unlock(bo->resv);
	}
	spin_unlock(&glob->lru_lock);

	if (ticket)
		ww_acquire_fini(ticket);
}
EXPORT_SYMBOL(ttm_eu_backoff_reservation);

/*
 * Reserve buffers for validation.
 *
 * If a buffer in the list is marked for CPU access, we back off and
 * wait for that buffer to become free for GPU access.
 *
 * If a buffer is reserved for another validation, the validator with
 * the highest validation sequence backs off and waits for that buffer
 * to become unreserved. This prevents deadlocks when validating multiple
 * buffers in different orders.
 */

int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket,
			   struct list_head *list, bool intr,
			   struct list_head *dups, bool del_lru)
{
	struct ttm_bo_global *glob;
	struct ttm_validate_buffer *entry;
	int ret;

	if (list_empty(list))
		return 0;

	entry = list_first_entry(list, struct ttm_validate_buffer, head);
	glob = entry->bo->bdev->glob;

	if (ticket)
		ww_acquire_init(ticket, &reservation_ww_class);

	list_for_each_entry(entry, list, head) {
		struct ttm_buffer_object *bo = entry->bo;

		ret = __ttm_bo_reserve(bo, intr, (ticket == NULL), ticket);
		if (!ret && unlikely(atomic_read(&bo->cpu_writers) > 0)) {
			reservation_object_unlock(bo->resv);

			ret = -EBUSY;

		} else if (ret == -EALREADY && dups) {
			struct ttm_validate_buffer *safe = entry;
			entry = list_prev_entry(entry, head);
			list_del(&safe->head);
			list_add(&safe->head, dups);
			continue;
		}

		if (!ret) {
			if (!entry->num_shared)
				continue;

			ret = reservation_object_reserve_shared(bo->resv,
								entry->num_shared);
			if (!ret)
				continue;
		}

		/* uh oh, we lost out, drop every reservation and try
		 * to only reserve this buffer, then start over if
		 * this succeeds.
		 */
		ttm_eu_backoff_reservation_reverse(list, entry);

		if (ret == -EDEADLK) {
			if (intr) {
				ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock,
								       ticket);
			} else {
				ww_mutex_lock_slow(&bo->resv->lock, ticket);
				ret = 0;
			}
		}

		if (!ret && entry->num_shared)
			ret = reservation_object_reserve_shared(bo->resv,
								entry->num_shared);

		if (unlikely(ret != 0)) {
			if (ret == -EINTR)
				ret = -ERESTARTSYS;
			if (ticket) {
				ww_acquire_done(ticket);
				ww_acquire_fini(ticket);
			}
			return ret;
		}

		/* move this item to the front of the list,
		 * forces correct iteration of the loop without keeping track
		 */
		list_del(&entry->head);
		list_add(&entry->head, list);
	}

	if (del_lru) {
		spin_lock(&glob->lru_lock);
		ttm_eu_del_from_lru_locked(list);
		spin_unlock(&glob->lru_lock);
	}
	return 0;
}
EXPORT_SYMBOL(ttm_eu_reserve_buffers);

void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,
				 struct list_head *list,
				 struct dma_fence *fence)
{
	struct ttm_validate_buffer *entry;
	struct ttm_buffer_object *bo;
	struct ttm_bo_global *glob;

	if (list_empty(list))
		return;

	bo = list_first_entry(list, struct ttm_validate_buffer, head)->bo;
	glob = bo->bdev->glob;

	spin_lock(&glob->lru_lock);

	list_for_each_entry(entry, list, head) {
		bo = entry->bo;
		if (entry->num_shared)
			reservation_object_add_shared_fence(bo->resv, fence);
		else
			reservation_object_add_excl_fence(bo->resv, fence);
		if (list_empty(&bo->lru))
			ttm_bo_add_to_lru(bo);
		else
			ttm_bo_move_to_lru_tail(bo, NULL);
		reservation_object_unlock(bo->resv);
	}
	spin_unlock(&glob->lru_lock);
	if (ticket)
		ww_acquire_fini(ticket);
}
EXPORT_SYMBOL(ttm_eu_fence_buffer_objects);