xref: /dflybsd-src/sys/dev/drm/ttm/ttm_execbuf_util.c (revision 1012d7827f4145ff76f5077a2d9a915880da2748)
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  * $FreeBSD: head/sys/dev/drm2/ttm/ttm_execbuf_util.c 247835 2013-03-05 09:49:34Z kib $
27  **************************************************************************/
28 
29 #include <dev/drm/drmP.h>
30 #include <dev/drm/ttm/ttm_execbuf_util.h>
31 #include <dev/drm/ttm/ttm_bo_driver.h>
32 #include <dev/drm/ttm/ttm_placement.h>
33 
34 static void ttm_eu_backoff_reservation_locked(struct list_head *list)
35 {
36 	struct ttm_validate_buffer *entry;
37 
38 	list_for_each_entry(entry, list, head) {
39 		struct ttm_buffer_object *bo = entry->bo;
40 		if (!entry->reserved)
41 			continue;
42 
43 		if (entry->removed) {
44 			ttm_bo_add_to_lru(bo);
45 			entry->removed = false;
46 
47 		}
48 		entry->reserved = false;
49 		atomic_set(&bo->reserved, 0);
50 		wakeup(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 static int ttm_eu_wait_unreserved_locked(struct list_head *list,
85 					 struct ttm_buffer_object *bo)
86 {
87 	int ret;
88 
89 	ttm_eu_del_from_lru_locked(list);
90 	ret = ttm_bo_wait_unreserved_locked(bo, true);
91 	if (unlikely(ret != 0))
92 		ttm_eu_backoff_reservation_locked(list);
93 	return ret;
94 }
95 
96 
97 void ttm_eu_backoff_reservation(struct list_head *list)
98 {
99 	struct ttm_validate_buffer *entry;
100 	struct ttm_bo_global *glob;
101 
102 	if (list_empty(list))
103 		return;
104 
105 	entry = list_first_entry(list, struct ttm_validate_buffer, head);
106 	glob = entry->bo->glob;
107 	lockmgr(&glob->lru_lock, LK_EXCLUSIVE);
108 	ttm_eu_backoff_reservation_locked(list);
109 	lockmgr(&glob->lru_lock, LK_RELEASE);
110 }
111 
112 /*
113  * Reserve buffers for validation.
114  *
115  * If a buffer in the list is marked for CPU access, we back off and
116  * wait for that buffer to become free for GPU access.
117  *
118  * If a buffer is reserved for another validation, the validator with
119  * the highest validation sequence backs off and waits for that buffer
120  * to become unreserved. This prevents deadlocks when validating multiple
121  * buffers in different orders.
122  */
123 
124 int ttm_eu_reserve_buffers(struct list_head *list)
125 {
126 	struct ttm_bo_global *glob;
127 	struct ttm_validate_buffer *entry;
128 	int ret;
129 	uint32_t val_seq;
130 
131 	if (list_empty(list))
132 		return 0;
133 
134 	list_for_each_entry(entry, list, head) {
135 		entry->reserved = false;
136 		entry->put_count = 0;
137 		entry->removed = false;
138 	}
139 
140 	entry = list_first_entry(list, struct ttm_validate_buffer, head);
141 	glob = entry->bo->glob;
142 
143 	lockmgr(&glob->lru_lock, LK_EXCLUSIVE);
144 retry_locked:
145 	val_seq = entry->bo->bdev->val_seq++;
146 
147 	list_for_each_entry(entry, list, head) {
148 		struct ttm_buffer_object *bo = entry->bo;
149 
150 retry_this_bo:
151 		ret = ttm_bo_reserve_locked(bo, true, true, true, val_seq);
152 		switch (ret) {
153 		case 0:
154 			break;
155 		case -EBUSY:
156 			ret = ttm_eu_wait_unreserved_locked(list, bo);
157 			if (unlikely(ret != 0)) {
158 				lockmgr(&glob->lru_lock, LK_RELEASE);
159 				ttm_eu_list_ref_sub(list);
160 				return ret;
161 			}
162 			goto retry_this_bo;
163 		case -EAGAIN:
164 			ttm_eu_backoff_reservation_locked(list);
165 			ttm_eu_list_ref_sub(list);
166 			ret = ttm_bo_wait_unreserved_locked(bo, true);
167 			if (unlikely(ret != 0)) {
168 				lockmgr(&glob->lru_lock, LK_RELEASE);
169 				return ret;
170 			}
171 			goto retry_locked;
172 		default:
173 			ttm_eu_backoff_reservation_locked(list);
174 			lockmgr(&glob->lru_lock, LK_RELEASE);
175 			ttm_eu_list_ref_sub(list);
176 			return ret;
177 		}
178 
179 		entry->reserved = true;
180 		if (unlikely(atomic_read(&bo->cpu_writers) > 0)) {
181 			ttm_eu_backoff_reservation_locked(list);
182 			lockmgr(&glob->lru_lock, LK_RELEASE);
183 			ttm_eu_list_ref_sub(list);
184 			return -EBUSY;
185 		}
186 	}
187 
188 	ttm_eu_del_from_lru_locked(list);
189 	lockmgr(&glob->lru_lock, LK_RELEASE);
190 	ttm_eu_list_ref_sub(list);
191 
192 	return 0;
193 }
194 
195 void ttm_eu_fence_buffer_objects(struct list_head *list, void *sync_obj)
196 {
197 	struct ttm_validate_buffer *entry;
198 	struct ttm_buffer_object *bo;
199 	struct ttm_bo_global *glob;
200 	struct ttm_bo_device *bdev;
201 	struct ttm_bo_driver *driver;
202 
203 	if (list_empty(list))
204 		return;
205 
206 	bo = list_first_entry(list, struct ttm_validate_buffer, head)->bo;
207 	bdev = bo->bdev;
208 	driver = bdev->driver;
209 	glob = bo->glob;
210 
211 	lockmgr(&glob->lru_lock, LK_EXCLUSIVE);
212 	lockmgr(&bdev->fence_lock, LK_EXCLUSIVE);
213 
214 	list_for_each_entry(entry, list, head) {
215 		bo = entry->bo;
216 		entry->old_sync_obj = bo->sync_obj;
217 		bo->sync_obj = driver->sync_obj_ref(sync_obj);
218 		ttm_bo_unreserve_locked(bo);
219 		entry->reserved = false;
220 	}
221 	lockmgr(&bdev->fence_lock, LK_RELEASE);
222 	lockmgr(&glob->lru_lock, LK_RELEASE);
223 
224 	list_for_each_entry(entry, list, head) {
225 		if (entry->old_sync_obj)
226 			driver->sync_obj_unref(&entry->old_sync_obj);
227 	}
228 }
229