1 /**************************************************************************
3 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
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:
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
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.
26 **************************************************************************/
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>
35 static void ttm_eu_backoff_reservation_locked(struct list_head *list)
37 struct ttm_validate_buffer *entry;
39 list_for_each_entry(entry, list, head) {
40 struct ttm_buffer_object *bo = entry->bo;
44 entry->reserved = false;
46 ttm_bo_add_to_lru(bo);
47 entry->removed = false;
49 ww_mutex_unlock(&bo->resv->lock);
53 static void ttm_eu_del_from_lru_locked(struct list_head *list)
55 struct ttm_validate_buffer *entry;
57 list_for_each_entry(entry, list, head) {
58 struct ttm_buffer_object *bo = entry->bo;
62 if (!entry->removed) {
63 entry->put_count = ttm_bo_del_from_lru(bo);
64 entry->removed = true;
69 static void ttm_eu_list_ref_sub(struct list_head *list)
71 struct ttm_validate_buffer *entry;
73 list_for_each_entry(entry, list, head) {
74 struct ttm_buffer_object *bo = entry->bo;
76 if (entry->put_count) {
77 ttm_bo_list_ref_sub(bo, entry->put_count, true);
83 void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket,
84 struct list_head *list)
86 struct ttm_validate_buffer *entry;
87 struct ttm_bo_global *glob;
92 entry = list_first_entry(list, struct ttm_validate_buffer, head);
93 glob = entry->bo->glob;
94 spin_lock(&glob->lru_lock);
95 ttm_eu_backoff_reservation_locked(list);
97 ww_acquire_fini(ticket);
98 spin_unlock(&glob->lru_lock);
100 EXPORT_SYMBOL(ttm_eu_backoff_reservation);
103 * Reserve buffers for validation.
105 * If a buffer in the list is marked for CPU access, we back off and
106 * wait for that buffer to become free for GPU access.
108 * If a buffer is reserved for another validation, the validator with
109 * the highest validation sequence backs off and waits for that buffer
110 * to become unreserved. This prevents deadlocks when validating multiple
111 * buffers in different orders.
114 int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket,
115 struct list_head *list)
117 struct ttm_bo_global *glob;
118 struct ttm_validate_buffer *entry;
121 if (list_empty(list))
124 list_for_each_entry(entry, list, head) {
125 entry->reserved = false;
126 entry->put_count = 0;
127 entry->removed = false;
130 entry = list_first_entry(list, struct ttm_validate_buffer, head);
131 glob = entry->bo->glob;
134 ww_acquire_init(ticket, &reservation_ww_class);
136 list_for_each_entry(entry, list, head) {
137 struct ttm_buffer_object *bo = entry->bo;
139 /* already slowpath reserved? */
143 ret = ttm_bo_reserve_nolru(bo, true, (ticket == NULL), true,
146 if (ret == -EDEADLK) {
147 /* uh oh, we lost out, drop every reservation and try
148 * to only reserve this buffer, then start over if
151 BUG_ON(ticket == NULL);
152 spin_lock(&glob->lru_lock);
153 ttm_eu_backoff_reservation_locked(list);
154 spin_unlock(&glob->lru_lock);
155 ttm_eu_list_ref_sub(list);
156 ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock,
158 if (unlikely(ret != 0)) {
164 entry->reserved = true;
165 if (unlikely(atomic_read(&bo->cpu_writers) > 0)) {
173 entry->reserved = true;
174 if (unlikely(atomic_read(&bo->cpu_writers) > 0)) {
181 ww_acquire_done(ticket);
182 spin_lock(&glob->lru_lock);
183 ttm_eu_del_from_lru_locked(list);
184 spin_unlock(&glob->lru_lock);
185 ttm_eu_list_ref_sub(list);
189 spin_lock(&glob->lru_lock);
190 ttm_eu_backoff_reservation_locked(list);
191 spin_unlock(&glob->lru_lock);
192 ttm_eu_list_ref_sub(list);
195 ww_acquire_done(ticket);
196 ww_acquire_fini(ticket);
200 EXPORT_SYMBOL(ttm_eu_reserve_buffers);
202 void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,
203 struct list_head *list, void *sync_obj)
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;
211 if (list_empty(list))
214 bo = list_first_entry(list, struct ttm_validate_buffer, head)->bo;
216 driver = bdev->driver;
219 spin_lock(&glob->lru_lock);
220 spin_lock(&bdev->fence_lock);
222 list_for_each_entry(entry, list, head) {
224 entry->old_sync_obj = bo->sync_obj;
225 bo->sync_obj = driver->sync_obj_ref(sync_obj);
226 ttm_bo_add_to_lru(bo);
227 ww_mutex_unlock(&bo->resv->lock);
228 entry->reserved = false;
230 spin_unlock(&bdev->fence_lock);
231 spin_unlock(&glob->lru_lock);
233 ww_acquire_fini(ticket);
235 list_for_each_entry(entry, list, head) {
236 if (entry->old_sync_obj)
237 driver->sync_obj_unref(&entry->old_sync_obj);
240 EXPORT_SYMBOL(ttm_eu_fence_buffer_objects);