1 /* SPDX-License-Identifier: GPL-2.0 OR MIT */
2 /**************************************************************************
3 *
4 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
5 * All Rights Reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the
9 * "Software"), to deal in the Software without restriction, including
10 * without limitation the rights to use, copy, modify, merge, publish,
11 * distribute, sub license, and/or sell copies of the Software, and to
12 * permit persons to whom the Software is furnished to do so, subject to
13 * the following conditions:
14 *
15 * The above copyright notice and this permission notice (including the
16 * next paragraph) shall be included in all copies or substantial portions
17 * of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
22 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
23 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
24 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
25 * USE OR OTHER DEALINGS IN THE SOFTWARE.
26 *
27 **************************************************************************/
28
29 #include <drm/ttm/ttm_execbuf_util.h>
30 #include <drm/ttm/ttm_bo_driver.h>
31 #include <drm/ttm/ttm_placement.h>
32 #include <linux/wait.h>
33 #include <linux/sched.h>
34 #include <linux/module.h>
35
ttm_eu_backoff_reservation_reverse(struct list_head * list,struct ttm_validate_buffer * entry)36 static void ttm_eu_backoff_reservation_reverse(struct list_head *list,
37 struct ttm_validate_buffer *entry)
38 {
39 list_for_each_entry_continue_reverse(entry, list, head) {
40 struct ttm_buffer_object *bo = entry->bo;
41
42 dma_resv_unlock(bo->base.resv);
43 }
44 }
45
ttm_eu_backoff_reservation(struct ww_acquire_ctx * ticket,struct list_head * list)46 void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket,
47 struct list_head *list)
48 {
49 struct ttm_validate_buffer *entry;
50
51 if (list_empty(list))
52 return;
53
54 list_for_each_entry(entry, list, head) {
55 struct ttm_buffer_object *bo = entry->bo;
56
57 ttm_bo_move_to_lru_tail_unlocked(bo);
58 dma_resv_unlock(bo->base.resv);
59 }
60
61 if (ticket)
62 ww_acquire_fini(ticket);
63 }
64 EXPORT_SYMBOL(ttm_eu_backoff_reservation);
65
66 /*
67 * Reserve buffers for validation.
68 *
69 * If a buffer in the list is marked for CPU access, we back off and
70 * wait for that buffer to become free for GPU access.
71 *
72 * If a buffer is reserved for another validation, the validator with
73 * the highest validation sequence backs off and waits for that buffer
74 * to become unreserved. This prevents deadlocks when validating multiple
75 * buffers in different orders.
76 */
77
ttm_eu_reserve_buffers(struct ww_acquire_ctx * ticket,struct list_head * list,bool intr,struct list_head * dups)78 int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket,
79 struct list_head *list, bool intr,
80 struct list_head *dups)
81 {
82 struct ttm_validate_buffer *entry;
83 int ret;
84
85 if (list_empty(list))
86 return 0;
87
88 if (ticket)
89 ww_acquire_init(ticket, &reservation_ww_class);
90
91 list_for_each_entry(entry, list, head) {
92 struct ttm_buffer_object *bo = entry->bo;
93
94 ret = ttm_bo_reserve(bo, intr, (ticket == NULL), ticket);
95 if (ret == -EALREADY && dups) {
96 struct ttm_validate_buffer *safe = entry;
97 entry = list_prev_entry(entry, head);
98 list_del(&safe->head);
99 list_add(&safe->head, dups);
100 continue;
101 }
102
103 if (!ret) {
104 if (!entry->num_shared)
105 continue;
106
107 ret = dma_resv_reserve_shared(bo->base.resv,
108 entry->num_shared);
109 if (!ret)
110 continue;
111 }
112
113 /* uh oh, we lost out, drop every reservation and try
114 * to only reserve this buffer, then start over if
115 * this succeeds.
116 */
117 ttm_eu_backoff_reservation_reverse(list, entry);
118
119 if (ret == -EDEADLK) {
120 ret = ttm_bo_reserve_slowpath(bo, intr, ticket);
121 }
122
123 if (!ret && entry->num_shared)
124 ret = dma_resv_reserve_shared(bo->base.resv,
125 entry->num_shared);
126
127 if (unlikely(ret != 0)) {
128 if (ticket) {
129 ww_acquire_done(ticket);
130 ww_acquire_fini(ticket);
131 }
132 return ret;
133 }
134
135 /* move this item to the front of the list,
136 * forces correct iteration of the loop without keeping track
137 */
138 list_del(&entry->head);
139 list_add(&entry->head, list);
140 }
141
142 return 0;
143 }
144 EXPORT_SYMBOL(ttm_eu_reserve_buffers);
145
ttm_eu_fence_buffer_objects(struct ww_acquire_ctx * ticket,struct list_head * list,struct dma_fence * fence)146 void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,
147 struct list_head *list,
148 struct dma_fence *fence)
149 {
150 struct ttm_validate_buffer *entry;
151
152 if (list_empty(list))
153 return;
154
155 list_for_each_entry(entry, list, head) {
156 struct ttm_buffer_object *bo = entry->bo;
157
158 if (entry->num_shared)
159 dma_resv_add_shared_fence(bo->base.resv, fence);
160 else
161 dma_resv_add_excl_fence(bo->base.resv, fence);
162 ttm_bo_move_to_lru_tail_unlocked(bo);
163 dma_resv_unlock(bo->base.resv);
164 }
165 if (ticket)
166 ww_acquire_fini(ticket);
167 }
168 EXPORT_SYMBOL(ttm_eu_fence_buffer_objects);
169