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_reverse(struct list_head *list,
36 struct ttm_validate_buffer *entry)
38 list_for_each_entry_continue_reverse(entry, list, head) {
39 struct ttm_buffer_object *bo = entry->bo;
41 __ttm_bo_unreserve(bo);
45 static void ttm_eu_del_from_lru_locked(struct list_head *list)
47 struct ttm_validate_buffer *entry;
49 list_for_each_entry(entry, list, head) {
50 struct ttm_buffer_object *bo = entry->bo;
51 unsigned put_count = ttm_bo_del_from_lru(bo);
53 ttm_bo_list_ref_sub(bo, put_count, true);
57 void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket,
58 struct list_head *list)
60 struct ttm_validate_buffer *entry;
61 struct ttm_bo_global *glob;
66 entry = list_first_entry(list, struct ttm_validate_buffer, head);
67 glob = entry->bo->glob;
69 spin_lock(&glob->lru_lock);
70 list_for_each_entry(entry, list, head) {
71 struct ttm_buffer_object *bo = entry->bo;
73 ttm_bo_add_to_lru(bo);
74 __ttm_bo_unreserve(bo);
76 spin_unlock(&glob->lru_lock);
79 ww_acquire_fini(ticket);
81 EXPORT_SYMBOL(ttm_eu_backoff_reservation);
84 * Reserve buffers for validation.
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.
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.
95 int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket,
96 struct list_head *list, bool intr)
98 struct ttm_bo_global *glob;
99 struct ttm_validate_buffer *entry;
102 if (list_empty(list))
105 entry = list_first_entry(list, struct ttm_validate_buffer, head);
106 glob = entry->bo->glob;
109 ww_acquire_init(ticket, &reservation_ww_class);
111 list_for_each_entry(entry, list, head) {
112 struct ttm_buffer_object *bo = entry->bo;
114 ret = __ttm_bo_reserve(bo, intr, (ticket == NULL), true,
116 if (!ret && unlikely(atomic_read(&bo->cpu_writers) > 0)) {
117 __ttm_bo_unreserve(bo);
125 /* uh oh, we lost out, drop every reservation and try
126 * to only reserve this buffer, then start over if
129 ttm_eu_backoff_reservation_reverse(list, entry);
131 if (ret == -EDEADLK && intr) {
132 ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock,
134 } else if (ret == -EDEADLK) {
135 ww_mutex_lock_slow(&bo->resv->lock, ticket);
139 if (unlikely(ret != 0)) {
143 ww_acquire_done(ticket);
144 ww_acquire_fini(ticket);
149 /* move this item to the front of the list,
150 * forces correct iteration of the loop without keeping track
152 list_del(&entry->head);
153 list_add(&entry->head, list);
157 ww_acquire_done(ticket);
158 spin_lock(&glob->lru_lock);
159 ttm_eu_del_from_lru_locked(list);
160 spin_unlock(&glob->lru_lock);
163 EXPORT_SYMBOL(ttm_eu_reserve_buffers);
165 void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,
166 struct list_head *list, struct fence *fence)
168 struct ttm_validate_buffer *entry;
169 struct ttm_buffer_object *bo;
170 struct ttm_bo_global *glob;
171 struct ttm_bo_device *bdev;
172 struct ttm_bo_driver *driver;
174 if (list_empty(list))
177 bo = list_first_entry(list, struct ttm_validate_buffer, head)->bo;
179 driver = bdev->driver;
182 spin_lock(&glob->lru_lock);
184 list_for_each_entry(entry, list, head) {
186 reservation_object_add_excl_fence(bo->resv, fence);
187 ttm_bo_add_to_lru(bo);
188 __ttm_bo_unreserve(bo);
190 spin_unlock(&glob->lru_lock);
192 ww_acquire_fini(ticket);
194 EXPORT_SYMBOL(ttm_eu_fence_buffer_objects);