1 /* SPDX-License-Identifier: GPL-2.0 OR MIT */
2 /**************************************************************************
3 *
4 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
5 * All Rights Reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the
9 * "Software"), to deal in the Software without restriction, including
10 * without limitation the rights to use, copy, modify, merge, publish,
11 * distribute, sub license, and/or sell copies of the Software, and to
12 * permit persons to whom the Software is furnished to do so, subject to
13 * the following conditions:
14 *
15 * The above copyright notice and this permission notice (including the
16 * next paragraph) shall be included in all copies or substantial portions
17 * of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
22 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
23 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
24 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
25 * USE OR OTHER DEALINGS IN THE SOFTWARE.
26 *
27 **************************************************************************/
28
29 #include <drm/ttm/ttm_execbuf_util.h>
30 #include <drm/ttm/ttm_bo_driver.h>
31 #include <drm/ttm/ttm_placement.h>
32 #include <linux/wait.h>
33 #include <linux/sched.h>
34 #include <linux/module.h>
35
ttm_eu_backoff_reservation_reverse(struct list_head * list,struct ttm_validate_buffer * entry)36 static void ttm_eu_backoff_reservation_reverse(struct list_head *list,
37 struct ttm_validate_buffer *entry)
38 {
39 list_for_each_entry_continue_reverse(entry, list, head) {
40 struct ttm_buffer_object *bo = entry->bo;
41
42 dma_resv_unlock(bo->base.resv);
43 }
44 }
45
ttm_eu_del_from_lru_locked(struct list_head * list)46 static void ttm_eu_del_from_lru_locked(struct list_head *list)
47 {
48 struct ttm_validate_buffer *entry;
49
50 list_for_each_entry(entry, list, head) {
51 struct ttm_buffer_object *bo = entry->bo;
52 ttm_bo_del_from_lru(bo);
53 }
54 }
55
ttm_eu_backoff_reservation(struct ww_acquire_ctx * ticket,struct list_head * list)56 void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket,
57 struct list_head *list)
58 {
59 struct ttm_validate_buffer *entry;
60 struct ttm_bo_global *glob;
61
62 if (list_empty(list))
63 return;
64
65 entry = list_first_entry(list, struct ttm_validate_buffer, head);
66 glob = entry->bo->bdev->glob;
67
68 spin_lock(&glob->lru_lock);
69 list_for_each_entry(entry, list, head) {
70 struct ttm_buffer_object *bo = entry->bo;
71
72 if (list_empty(&bo->lru))
73 ttm_bo_add_to_lru(bo);
74 dma_resv_unlock(bo->base.resv);
75 }
76 spin_unlock(&glob->lru_lock);
77
78 if (ticket)
79 ww_acquire_fini(ticket);
80 }
81 EXPORT_SYMBOL(ttm_eu_backoff_reservation);
82
83 /*
84 * Reserve buffers for validation.
85 *
86 * If a buffer in the list is marked for CPU access, we back off and
87 * wait for that buffer to become free for GPU access.
88 *
89 * If a buffer is reserved for another validation, the validator with
90 * the highest validation sequence backs off and waits for that buffer
91 * to become unreserved. This prevents deadlocks when validating multiple
92 * buffers in different orders.
93 */
94
ttm_eu_reserve_buffers(struct ww_acquire_ctx * ticket,struct list_head * list,bool intr,struct list_head * dups,bool del_lru)95 int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket,
96 struct list_head *list, bool intr,
97 struct list_head *dups, bool del_lru)
98 {
99 struct ttm_bo_global *glob;
100 struct ttm_validate_buffer *entry;
101 int ret;
102
103 if (list_empty(list))
104 return 0;
105
106 entry = list_first_entry(list, struct ttm_validate_buffer, head);
107 glob = entry->bo->bdev->glob;
108
109 if (ticket)
110 ww_acquire_init(ticket, &reservation_ww_class);
111
112 list_for_each_entry(entry, list, head) {
113 struct ttm_buffer_object *bo = entry->bo;
114
115 ret = __ttm_bo_reserve(bo, intr, (ticket == NULL), ticket);
116 if (!ret && unlikely(atomic_read(&bo->cpu_writers) > 0)) {
117 dma_resv_unlock(bo->base.resv);
118
119 ret = -EBUSY;
120
121 } else if (ret == -EALREADY && dups) {
122 struct ttm_validate_buffer *safe = entry;
123 entry = list_prev_entry(entry, head);
124 list_del(&safe->head);
125 list_add(&safe->head, dups);
126 continue;
127 }
128
129 if (!ret) {
130 if (!entry->num_shared)
131 continue;
132
133 ret = dma_resv_reserve_shared(bo->base.resv,
134 entry->num_shared);
135 if (!ret)
136 continue;
137 }
138
139 /* uh oh, we lost out, drop every reservation and try
140 * to only reserve this buffer, then start over if
141 * this succeeds.
142 */
143 ttm_eu_backoff_reservation_reverse(list, entry);
144
145 if (ret == -EDEADLK) {
146 if (intr) {
147 ret = dma_resv_lock_slow_interruptible(bo->base.resv,
148 ticket);
149 } else {
150 dma_resv_lock_slow(bo->base.resv, ticket);
151 ret = 0;
152 }
153 }
154
155 if (!ret && entry->num_shared)
156 ret = dma_resv_reserve_shared(bo->base.resv,
157 entry->num_shared);
158
159 if (unlikely(ret != 0)) {
160 if (ret == -EINTR)
161 ret = -ERESTARTSYS;
162 if (ticket) {
163 ww_acquire_done(ticket);
164 ww_acquire_fini(ticket);
165 }
166 return ret;
167 }
168
169 /* move this item to the front of the list,
170 * forces correct iteration of the loop without keeping track
171 */
172 list_del(&entry->head);
173 list_add(&entry->head, list);
174 }
175
176 if (del_lru) {
177 spin_lock(&glob->lru_lock);
178 ttm_eu_del_from_lru_locked(list);
179 spin_unlock(&glob->lru_lock);
180 }
181 return 0;
182 }
183 EXPORT_SYMBOL(ttm_eu_reserve_buffers);
184
ttm_eu_fence_buffer_objects(struct ww_acquire_ctx * ticket,struct list_head * list,struct dma_fence * fence)185 void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,
186 struct list_head *list,
187 struct dma_fence *fence)
188 {
189 struct ttm_validate_buffer *entry;
190 struct ttm_buffer_object *bo;
191 struct ttm_bo_global *glob;
192
193 if (list_empty(list))
194 return;
195
196 bo = list_first_entry(list, struct ttm_validate_buffer, head)->bo;
197 glob = bo->bdev->glob;
198
199 spin_lock(&glob->lru_lock);
200
201 list_for_each_entry(entry, list, head) {
202 bo = entry->bo;
203 if (entry->num_shared)
204 dma_resv_add_shared_fence(bo->base.resv, fence);
205 else
206 dma_resv_add_excl_fence(bo->base.resv, fence);
207 if (list_empty(&bo->lru))
208 ttm_bo_add_to_lru(bo);
209 else
210 ttm_bo_move_to_lru_tail(bo, NULL);
211 dma_resv_unlock(bo->base.resv);
212 }
213 spin_unlock(&glob->lru_lock);
214 if (ticket)
215 ww_acquire_fini(ticket);
216 }
217 EXPORT_SYMBOL(ttm_eu_fence_buffer_objects);
218
