ttm_execbuf_util.c revision 254861 
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 <sys/cdefs.h>
29__FBSDID("$FreeBSD: head/sys/dev/drm2/ttm/ttm_execbuf_util.c 254861 2013-08-25 14:39:51Z dumbbell $");
30
31#include <dev/drm2/drmP.h>
32#include <dev/drm2/ttm/ttm_execbuf_util.h>
33#include <dev/drm2/ttm/ttm_bo_driver.h>
34#include <dev/drm2/ttm/ttm_placement.h>
35
36static 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		if (entry->removed) {
46			ttm_bo_add_to_lru(bo);
47			entry->removed = false;
48
49		}
50		entry->reserved = false;
51		atomic_set(&bo->reserved, 0);
52		wakeup(bo);
53	}
54}
55
56static void ttm_eu_del_from_lru_locked(struct list_head *list)
57{
58	struct ttm_validate_buffer *entry;
59
60	list_for_each_entry(entry, list, head) {
61		struct ttm_buffer_object *bo = entry->bo;
62		if (!entry->reserved)
63			continue;
64
65		if (!entry->removed) {
66			entry->put_count = ttm_bo_del_from_lru(bo);
67			entry->removed = true;
68		}
69	}
70}
71
72static void ttm_eu_list_ref_sub(struct list_head *list)
73{
74	struct ttm_validate_buffer *entry;
75
76	list_for_each_entry(entry, list, head) {
77		struct ttm_buffer_object *bo = entry->bo;
78
79		if (entry->put_count) {
80			ttm_bo_list_ref_sub(bo, entry->put_count, true);
81			entry->put_count = 0;
82		}
83	}
84}
85
86static int ttm_eu_wait_unreserved_locked(struct list_head *list,
87					 struct ttm_buffer_object *bo)
88{
89	int ret;
90
91	ttm_eu_del_from_lru_locked(list);
92	ret = ttm_bo_wait_unreserved_locked(bo, true);
93	if (unlikely(ret != 0))
94		ttm_eu_backoff_reservation_locked(list);
95	return ret;
96}
97
98
99void ttm_eu_backoff_reservation(struct list_head *list)
100{
101	struct ttm_validate_buffer *entry;
102	struct ttm_bo_global *glob;
103
104	if (list_empty(list))
105		return;
106
107	entry = list_first_entry(list, struct ttm_validate_buffer, head);
108	glob = entry->bo->glob;
109	mtx_lock(&glob->lru_lock);
110	ttm_eu_backoff_reservation_locked(list);
111	mtx_unlock(&glob->lru_lock);
112}
113
114/*
115 * Reserve buffers for validation.
116 *
117 * If a buffer in the list is marked for CPU access, we back off and
118 * wait for that buffer to become free for GPU access.
119 *
120 * If a buffer is reserved for another validation, the validator with
121 * the highest validation sequence backs off and waits for that buffer
122 * to become unreserved. This prevents deadlocks when validating multiple
123 * buffers in different orders.
124 */
125
126int ttm_eu_reserve_buffers(struct list_head *list)
127{
128	struct ttm_bo_global *glob;
129	struct ttm_validate_buffer *entry;
130	int ret;
131	uint32_t val_seq;
132
133	if (list_empty(list))
134		return 0;
135
136	list_for_each_entry(entry, list, head) {
137		entry->reserved = false;
138		entry->put_count = 0;
139		entry->removed = false;
140	}
141
142	entry = list_first_entry(list, struct ttm_validate_buffer, head);
143	glob = entry->bo->glob;
144
145	mtx_lock(&glob->lru_lock);
146retry_locked:
147	val_seq = entry->bo->bdev->val_seq++;
148
149	list_for_each_entry(entry, list, head) {
150		struct ttm_buffer_object *bo = entry->bo;
151
152retry_this_bo:
153		ret = ttm_bo_reserve_nolru(bo, true, true, true, val_seq);
154		switch (ret) {
155		case 0:
156			break;
157		case -EBUSY:
158			ret = ttm_eu_wait_unreserved_locked(list, bo);
159			if (unlikely(ret != 0)) {
160				mtx_unlock(&glob->lru_lock);
161				ttm_eu_list_ref_sub(list);
162				return ret;
163			}
164			goto retry_this_bo;
165		case -EAGAIN:
166			ttm_eu_backoff_reservation_locked(list);
167			ttm_eu_list_ref_sub(list);
168			ret = ttm_bo_wait_unreserved_locked(bo, true);
169			if (unlikely(ret != 0)) {
170				mtx_unlock(&glob->lru_lock);
171				return ret;
172			}
173			goto retry_locked;
174		default:
175			ttm_eu_backoff_reservation_locked(list);
176			mtx_unlock(&glob->lru_lock);
177			ttm_eu_list_ref_sub(list);
178			return ret;
179		}
180
181		entry->reserved = true;
182		if (unlikely(atomic_read(&bo->cpu_writers) > 0)) {
183			ttm_eu_backoff_reservation_locked(list);
184			mtx_unlock(&glob->lru_lock);
185			ttm_eu_list_ref_sub(list);
186			return -EBUSY;
187		}
188	}
189
190	ttm_eu_del_from_lru_locked(list);
191	mtx_unlock(&glob->lru_lock);
192	ttm_eu_list_ref_sub(list);
193
194	return 0;
195}
196
197void ttm_eu_fence_buffer_objects(struct list_head *list, void *sync_obj)
198{
199	struct ttm_validate_buffer *entry;
200	struct ttm_buffer_object *bo;
201	struct ttm_bo_global *glob;
202	struct ttm_bo_device *bdev;
203	struct ttm_bo_driver *driver;
204
205	if (list_empty(list))
206		return;
207
208	bo = list_first_entry(list, struct ttm_validate_buffer, head)->bo;
209	bdev = bo->bdev;
210	driver = bdev->driver;
211	glob = bo->glob;
212
213	mtx_lock(&glob->lru_lock);
214	mtx_lock(&bdev->fence_lock);
215
216	list_for_each_entry(entry, list, head) {
217		bo = entry->bo;
218		entry->old_sync_obj = bo->sync_obj;
219		bo->sync_obj = driver->sync_obj_ref(sync_obj);
220		ttm_bo_unreserve_locked(bo);
221		entry->reserved = false;
222	}
223	mtx_unlock(&bdev->fence_lock);
224	mtx_unlock(&glob->lru_lock);
225
226	list_for_each_entry(entry, list, head) {
227		if (entry->old_sync_obj)
228			driver->sync_obj_unref(&entry->old_sync_obj);
229	}
230}
231