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