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 unsigned put_count = ttm_bo_del_from_lru(bo);
52
53 ttm_bo_list_ref_sub(bo, put_count, true);
54 }
55 }
56
ttm_eu_backoff_reservation(struct ww_acquire_ctx * ticket,struct list_head * list)57 void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket,
58 struct list_head *list)
59 {
60 struct ttm_validate_buffer *entry;
61 struct ttm_bo_global *glob;
62
63 if (list_empty(list))
64 return;
65
66 entry = list_first_entry(list, struct ttm_validate_buffer, head);
67 glob = entry->bo->glob;
68
69 spin_lock(&glob->lru_lock);
70 list_for_each_entry(entry, list, head) {
71 struct ttm_buffer_object *bo = entry->bo;
72
73 ttm_bo_add_to_lru(bo);
74 __ttm_bo_unreserve(bo);
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)95 int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket,
96 struct list_head *list, bool intr,
97 struct list_head *dups)
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->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 __ttm_bo_unreserve(bo);
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->shared)
131 continue;
132
133 ret = reservation_object_reserve_shared(bo->resv);
134 if (!ret)
135 continue;
136 }
137
138 /* uh oh, we lost out, drop every reservation and try
139 * to only reserve this buffer, then start over if
140 * this succeeds.
141 */
142 ttm_eu_backoff_reservation_reverse(list, entry);
143
144 if (ret == -EDEADLK && intr) {
145 ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock,
146 ticket);
147 } else if (ret == -EDEADLK) {
148 ww_mutex_lock_slow(&bo->resv->lock, ticket);
149 ret = 0;
150 }
151
152 if (!ret && entry->shared)
153 ret = reservation_object_reserve_shared(bo->resv);
154
155 if (unlikely(ret != 0)) {
156 if (ret == -EINTR)
157 ret = -ERESTARTSYS;
158 if (ticket) {
159 ww_acquire_done(ticket);
160 ww_acquire_fini(ticket);
161 }
162 return ret;
163 }
164
165 /* move this item to the front of the list,
166 * forces correct iteration of the loop without keeping track
167 */
168 list_del(&entry->head);
169 list_add(&entry->head, list);
170 }
171
172 if (ticket)
173 ww_acquire_done(ticket);
174 spin_lock(&glob->lru_lock);
175 ttm_eu_del_from_lru_locked(list);
176 spin_unlock(&glob->lru_lock);
177 return 0;
178 }
179 EXPORT_SYMBOL(ttm_eu_reserve_buffers);
180
ttm_eu_fence_buffer_objects(struct ww_acquire_ctx * ticket,struct list_head * list,struct fence * fence)181 void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,
182 struct list_head *list, struct fence *fence)
183 {
184 struct ttm_validate_buffer *entry;
185 struct ttm_buffer_object *bo;
186 struct ttm_bo_global *glob;
187 struct ttm_bo_device *bdev;
188 struct ttm_bo_driver *driver;
189
190 if (list_empty(list))
191 return;
192
193 bo = list_first_entry(list, struct ttm_validate_buffer, head)->bo;
194 bdev = bo->bdev;
195 driver = bdev->driver;
196 glob = bo->glob;
197
198 spin_lock(&glob->lru_lock);
199
200 list_for_each_entry(entry, list, head) {
201 bo = entry->bo;
202 if (entry->shared)
203 reservation_object_add_shared_fence(bo->resv, fence);
204 else
205 reservation_object_add_excl_fence(bo->resv, fence);
206 ttm_bo_add_to_lru(bo);
207 __ttm_bo_unreserve(bo);
208 }
209 spin_unlock(&glob->lru_lock);
210 if (ticket)
211 ww_acquire_fini(ticket);
212 }
213 EXPORT_SYMBOL(ttm_eu_fence_buffer_objects);
214