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 | #include <linux/export.h> |
35 | |
36 | static void ttm_eu_backoff_reservation_locked(struct list_head *list) |
37 | { |
38 | struct ttm_validate_buffer *entry; |
39 | |
40 | list_for_each_entry(entry, list, head) { |
41 | struct ttm_buffer_object *bo = entry->bo; |
42 | if (!entry->reserved) |
43 | continue; |
44 | |
45 | entry->reserved = false; |
46 | if (entry->removed) { |
47 | ttm_bo_add_to_lru(bo); |
48 | entry->removed = false; |
49 | } |
50 | __ttm_bo_unreserve(bo); |
51 | } |
52 | } |
53 | |
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 | |
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 | |
84 | void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket, |
85 | struct list_head *list) |
86 | { |
87 | struct ttm_validate_buffer *entry; |
88 | struct ttm_bo_global *glob; |
89 | |
90 | if (list_empty(list)) |
91 | return; |
92 | |
93 | entry = list_first_entry(list, struct ttm_validate_buffer, head); |
94 | glob = entry->bo->glob; |
95 | spin_lock(&glob->lru_lock); |
96 | ttm_eu_backoff_reservation_locked(list); |
97 | if (ticket) |
98 | ww_acquire_fini(ticket); |
99 | spin_unlock(&glob->lru_lock); |
100 | } |
101 | EXPORT_SYMBOL(ttm_eu_backoff_reservation); |
102 | |
103 | /* |
104 | * Reserve buffers for validation. |
105 | * |
106 | * If a buffer in the list is marked for CPU access, we back off and |
107 | * wait for that buffer to become free for GPU access. |
108 | * |
109 | * If a buffer is reserved for another validation, the validator with |
110 | * the highest validation sequence backs off and waits for that buffer |
111 | * to become unreserved. This prevents deadlocks when validating multiple |
112 | * buffers in different orders. |
113 | */ |
114 | |
115 | int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket, |
116 | struct list_head *list) |
117 | { |
118 | struct ttm_bo_global *glob; |
119 | struct ttm_validate_buffer *entry; |
120 | int ret; |
121 | |
122 | if (list_empty(list)) |
123 | return 0; |
124 | |
125 | list_for_each_entry(entry, list, head) { |
126 | entry->reserved = false; |
127 | entry->put_count = 0; |
128 | entry->removed = false; |
129 | } |
130 | |
131 | entry = list_first_entry(list, struct ttm_validate_buffer, head); |
132 | glob = entry->bo->glob; |
133 | |
134 | if (ticket) |
135 | ww_acquire_init(ticket, &reservation_ww_class); |
136 | retry: |
137 | list_for_each_entry(entry, list, head) { |
138 | struct ttm_buffer_object *bo = entry->bo; |
139 | |
140 | /* already slowpath reserved? */ |
141 | if (entry->reserved) |
142 | continue; |
143 | |
144 | ret = __ttm_bo_reserve(bo, true, (ticket == NULL), true, |
145 | ticket); |
146 | |
147 | if (ret == -EDEADLK) { |
148 | /* uh oh, we lost out, drop every reservation and try |
149 | * to only reserve this buffer, then start over if |
150 | * this succeeds. |
151 | */ |
152 | BUG_ON(ticket == NULL); |
153 | spin_lock(&glob->lru_lock); |
154 | ttm_eu_backoff_reservation_locked(list); |
155 | spin_unlock(&glob->lru_lock); |
156 | ttm_eu_list_ref_sub(list); |
157 | ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock, |
158 | ticket); |
159 | if (unlikely(ret != 0)) { |
160 | if (ret == -EINTR) |
161 | ret = -ERESTARTSYS; |
162 | goto err_fini; |
163 | } |
164 | |
165 | entry->reserved = true; |
166 | if (unlikely(atomic_read(&bo->cpu_writers) > 0)) { |
167 | ret = -EBUSY; |
168 | goto err; |
169 | } |
170 | goto retry; |
171 | } else if (ret) |
172 | goto err; |
173 | |
174 | entry->reserved = true; |
175 | if (unlikely(atomic_read(&bo->cpu_writers) > 0)) { |
176 | ret = -EBUSY; |
177 | goto err; |
178 | } |
179 | } |
180 | |
181 | if (ticket) |
182 | ww_acquire_done(ticket); |
183 | spin_lock(&glob->lru_lock); |
184 | ttm_eu_del_from_lru_locked(list); |
185 | spin_unlock(&glob->lru_lock); |
186 | ttm_eu_list_ref_sub(list); |
187 | return 0; |
188 | |
189 | err: |
190 | spin_lock(&glob->lru_lock); |
191 | ttm_eu_backoff_reservation_locked(list); |
192 | spin_unlock(&glob->lru_lock); |
193 | ttm_eu_list_ref_sub(list); |
194 | err_fini: |
195 | if (ticket) { |
196 | ww_acquire_done(ticket); |
197 | ww_acquire_fini(ticket); |
198 | } |
199 | return ret; |
200 | } |
201 | EXPORT_SYMBOL(ttm_eu_reserve_buffers); |
202 | |
203 | void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket, |
204 | struct list_head *list, void *sync_obj) |
205 | { |
206 | struct ttm_validate_buffer *entry; |
207 | struct ttm_buffer_object *bo; |
208 | struct ttm_bo_global *glob; |
209 | struct ttm_bo_device *bdev; |
210 | struct ttm_bo_driver *driver; |
211 | |
212 | if (list_empty(list)) |
213 | return; |
214 | |
215 | bo = list_first_entry(list, struct ttm_validate_buffer, head)->bo; |
216 | bdev = bo->bdev; |
217 | driver = bdev->driver; |
218 | glob = bo->glob; |
219 | |
220 | spin_lock(&glob->lru_lock); |
221 | spin_lock(&bdev->fence_lock); |
222 | |
223 | list_for_each_entry(entry, list, head) { |
224 | bo = entry->bo; |
225 | entry->old_sync_obj = bo->sync_obj; |
226 | bo->sync_obj = driver->sync_obj_ref(sync_obj); |
227 | ttm_bo_add_to_lru(bo); |
228 | __ttm_bo_unreserve(bo); |
229 | entry->reserved = false; |
230 | } |
231 | spin_unlock(&bdev->fence_lock); |
232 | spin_unlock(&glob->lru_lock); |
233 | if (ticket) |
234 | ww_acquire_fini(ticket); |
235 | |
236 | list_for_each_entry(entry, list, head) { |
237 | if (entry->old_sync_obj) |
238 | driver->sync_obj_unref(&entry->old_sync_obj); |
239 | } |
240 | } |
241 | EXPORT_SYMBOL(ttm_eu_fence_buffer_objects); |
242 | |