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 <sys/cdefs.h>
29 #include <dev/drm2/drmP.h>
30 #include <dev/drm2/ttm/ttm_execbuf_util.h>
31 #include <dev/drm2/ttm/ttm_bo_driver.h>
32 #include <dev/drm2/ttm/ttm_placement.h>
33
ttm_eu_backoff_reservation_locked(struct list_head * list)34 static void ttm_eu_backoff_reservation_locked(struct list_head *list)
35 {
36 struct ttm_validate_buffer *entry;
37
38 list_for_each_entry(entry, list, head) {
39 struct ttm_buffer_object *bo = entry->bo;
40 if (!entry->reserved)
41 continue;
42
43 if (entry->removed) {
44 ttm_bo_add_to_lru(bo);
45 entry->removed = false;
46
47 }
48 entry->reserved = false;
49 atomic_set(&bo->reserved, 0);
50 wakeup(bo);
51 }
52 }
53
ttm_eu_del_from_lru_locked(struct list_head * list)54 static void ttm_eu_del_from_lru_locked(struct list_head *list)
55 {
56 struct ttm_validate_buffer *entry;
57
58 list_for_each_entry(entry, list, head) {
59 struct ttm_buffer_object *bo = entry->bo;
60 if (!entry->reserved)
61 continue;
62
63 if (!entry->removed) {
64 entry->put_count = ttm_bo_del_from_lru(bo);
65 entry->removed = true;
66 }
67 }
68 }
69
ttm_eu_list_ref_sub(struct list_head * list)70 static void ttm_eu_list_ref_sub(struct list_head *list)
71 {
72 struct ttm_validate_buffer *entry;
73
74 list_for_each_entry(entry, list, head) {
75 struct ttm_buffer_object *bo = entry->bo;
76
77 if (entry->put_count) {
78 ttm_bo_list_ref_sub(bo, entry->put_count, true);
79 entry->put_count = 0;
80 }
81 }
82 }
83
ttm_eu_backoff_reservation(struct list_head * list)84 void ttm_eu_backoff_reservation(struct list_head *list)
85 {
86 struct ttm_validate_buffer *entry;
87 struct ttm_bo_global *glob;
88
89 if (list_empty(list))
90 return;
91
92 entry = list_first_entry(list, struct ttm_validate_buffer, head);
93 glob = entry->bo->glob;
94 mtx_lock(&glob->lru_lock);
95 ttm_eu_backoff_reservation_locked(list);
96 mtx_unlock(&glob->lru_lock);
97 }
98
99 /*
100 * Reserve buffers for validation.
101 *
102 * If a buffer in the list is marked for CPU access, we back off and
103 * wait for that buffer to become free for GPU access.
104 *
105 * If a buffer is reserved for another validation, the validator with
106 * the highest validation sequence backs off and waits for that buffer
107 * to become unreserved. This prevents deadlocks when validating multiple
108 * buffers in different orders.
109 */
110
ttm_eu_reserve_buffers(struct list_head * list)111 int ttm_eu_reserve_buffers(struct list_head *list)
112 {
113 struct ttm_bo_global *glob;
114 struct ttm_validate_buffer *entry;
115 int ret;
116 uint32_t val_seq;
117
118 if (list_empty(list))
119 return 0;
120
121 list_for_each_entry(entry, list, head) {
122 entry->reserved = false;
123 entry->put_count = 0;
124 entry->removed = false;
125 }
126
127 entry = list_first_entry(list, struct ttm_validate_buffer, head);
128 glob = entry->bo->glob;
129
130 mtx_lock(&glob->lru_lock);
131 val_seq = entry->bo->bdev->val_seq++;
132
133 retry_locked:
134 list_for_each_entry(entry, list, head) {
135 struct ttm_buffer_object *bo = entry->bo;
136
137 /* already slowpath reserved? */
138 if (entry->reserved)
139 continue;
140
141 ret = ttm_bo_reserve_nolru(bo, true, true, true, val_seq);
142 switch (ret) {
143 case 0:
144 break;
145 case -EBUSY:
146 ttm_eu_del_from_lru_locked(list);
147 ret = ttm_bo_reserve_nolru(bo, true, false,
148 true, val_seq);
149 if (!ret)
150 break;
151
152 if (unlikely(ret != -EAGAIN))
153 goto err;
154
155 /* fallthrough */
156 case -EAGAIN:
157 ttm_eu_backoff_reservation_locked(list);
158
159 /*
160 * temporarily increase sequence number every retry,
161 * to prevent us from seeing our old reservation
162 * sequence when someone else reserved the buffer,
163 * but hasn't updated the seq_valid/seqno members yet.
164 */
165 val_seq = entry->bo->bdev->val_seq++;
166
167 ttm_eu_list_ref_sub(list);
168 ret = ttm_bo_reserve_slowpath_nolru(bo, true, val_seq);
169 if (unlikely(ret != 0)) {
170 mtx_unlock(&glob->lru_lock);
171 return ret;
172 }
173 entry->reserved = true;
174 if (unlikely(atomic_read(&bo->cpu_writers) > 0)) {
175 ret = -EBUSY;
176 goto err;
177 }
178 goto retry_locked;
179 default:
180 goto err;
181 }
182
183 entry->reserved = true;
184 if (unlikely(atomic_read(&bo->cpu_writers) > 0)) {
185 ret = -EBUSY;
186 goto err;
187 }
188 }
189
190 ttm_eu_del_from_lru_locked(list);
191 mtx_unlock(&glob->lru_lock);
192 ttm_eu_list_ref_sub(list);
193
194 return 0;
195
196 err:
197 ttm_eu_backoff_reservation_locked(list);
198 mtx_unlock(&glob->lru_lock);
199 ttm_eu_list_ref_sub(list);
200 return ret;
201 }
202
ttm_eu_fence_buffer_objects(struct list_head * list,void * sync_obj)203 void ttm_eu_fence_buffer_objects(struct list_head *list, void *sync_obj)
204 {
205 struct ttm_validate_buffer *entry;
206 struct ttm_buffer_object *bo;
207 struct ttm_bo_global *glob;
208 struct ttm_bo_device *bdev;
209 struct ttm_bo_driver *driver;
210
211 if (list_empty(list))
212 return;
213
214 bo = list_first_entry(list, struct ttm_validate_buffer, head)->bo;
215 bdev = bo->bdev;
216 driver = bdev->driver;
217 glob = bo->glob;
218
219 mtx_lock(&glob->lru_lock);
220 mtx_lock(&bdev->fence_lock);
221
222 list_for_each_entry(entry, list, head) {
223 bo = entry->bo;
224 entry->old_sync_obj = bo->sync_obj;
225 bo->sync_obj = driver->sync_obj_ref(sync_obj);
226 ttm_bo_unreserve_locked(bo);
227 entry->reserved = false;
228 }
229 mtx_unlock(&bdev->fence_lock);
230 mtx_unlock(&glob->lru_lock);
231
232 list_for_each_entry(entry, list, head) {
233 if (entry->old_sync_obj)
234 driver->sync_obj_unref(&entry->old_sync_obj);
235 }
236 }
237