ttm_execbuf_util.c revision 1.2.30.2
1 /* $NetBSD: ttm_execbuf_util.c,v 1.2.30.2 2020/04/08 14:08:26 martin Exp $ */ 2 3 /************************************************************************** 4 * 5 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA 6 * All Rights Reserved. 7 * 8 * Permission is hereby granted, free of charge, to any person obtaining a 9 * copy of this software and associated documentation files (the 10 * "Software"), to deal in the Software without restriction, including 11 * without limitation the rights to use, copy, modify, merge, publish, 12 * distribute, sub license, and/or sell copies of the Software, and to 13 * permit persons to whom the Software is furnished to do so, subject to 14 * the following conditions: 15 * 16 * The above copyright notice and this permission notice (including the 17 * next paragraph) shall be included in all copies or substantial portions 18 * of the Software. 19 * 20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL 23 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, 24 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR 25 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE 26 * USE OR OTHER DEALINGS IN THE SOFTWARE. 27 * 28 **************************************************************************/ 29 30 #include <sys/cdefs.h> 31 __KERNEL_RCSID(0, "$NetBSD: ttm_execbuf_util.c,v 1.2.30.2 2020/04/08 14:08:26 martin Exp $"); 32 33 #include <drm/ttm/ttm_execbuf_util.h> 34 #include <drm/ttm/ttm_bo_driver.h> 35 #include <drm/ttm/ttm_placement.h> 36 #include <linux/wait.h> 37 #include <linux/sched.h> 38 #include <linux/module.h> 39 40 static void ttm_eu_backoff_reservation_reverse(struct list_head *list, 41 struct ttm_validate_buffer *entry) 42 { 43 list_for_each_entry_continue_reverse(entry, list, head) { 44 struct ttm_buffer_object *bo = entry->bo; 45 46 __ttm_bo_unreserve(bo); 47 } 48 } 49 50 static void ttm_eu_del_from_lru_locked(struct list_head *list) 51 { 52 struct ttm_validate_buffer *entry; 53 54 list_for_each_entry(entry, list, head) { 55 struct ttm_buffer_object *bo = entry->bo; 56 unsigned put_count = ttm_bo_del_from_lru(bo); 57 58 ttm_bo_list_ref_sub(bo, put_count, true); 59 } 60 } 61 62 void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket, 63 struct list_head *list) 64 { 65 struct ttm_validate_buffer *entry; 66 struct ttm_bo_global *glob; 67 68 if (list_empty(list)) 69 return; 70 71 entry = list_first_entry(list, struct ttm_validate_buffer, head); 72 glob = entry->bo->glob; 73 74 spin_lock(&glob->lru_lock); 75 list_for_each_entry(entry, list, head) { 76 struct ttm_buffer_object *bo = entry->bo; 77 78 ttm_bo_add_to_lru(bo); 79 __ttm_bo_unreserve(bo); 80 } 81 spin_unlock(&glob->lru_lock); 82 83 if (ticket) 84 ww_acquire_fini(ticket); 85 } 86 EXPORT_SYMBOL(ttm_eu_backoff_reservation); 87 88 /* 89 * Reserve buffers for validation. 90 * 91 * If a buffer in the list is marked for CPU access, we back off and 92 * wait for that buffer to become free for GPU access. 93 * 94 * If a buffer is reserved for another validation, the validator with 95 * the highest validation sequence backs off and waits for that buffer 96 * to become unreserved. This prevents deadlocks when validating multiple 97 * buffers in different orders. 98 */ 99 100 int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket, 101 struct list_head *list, bool intr, 102 struct list_head *dups) 103 { 104 struct ttm_bo_global *glob; 105 struct ttm_validate_buffer *entry; 106 int ret; 107 108 if (list_empty(list)) 109 return 0; 110 111 entry = list_first_entry(list, struct ttm_validate_buffer, head); 112 glob = entry->bo->glob; 113 114 if (ticket) 115 ww_acquire_init(ticket, &reservation_ww_class); 116 117 list_for_each_entry(entry, list, head) { 118 struct ttm_buffer_object *bo = entry->bo; 119 120 ret = __ttm_bo_reserve(bo, intr, (ticket == NULL), true, 121 ticket); 122 if (!ret && unlikely(atomic_read(&bo->cpu_writers) > 0)) { 123 __ttm_bo_unreserve(bo); 124 125 ret = -EBUSY; 126 127 } else if (ret == -EALREADY && dups) { 128 struct ttm_validate_buffer *safe = entry; 129 entry = list_prev_entry(entry, head); 130 list_del(&safe->head); 131 list_add(&safe->head, dups); 132 continue; 133 } 134 135 if (!ret) { 136 if (!entry->shared) 137 continue; 138 139 ret = reservation_object_reserve_shared(bo->resv); 140 if (!ret) 141 continue; 142 } 143 144 /* uh oh, we lost out, drop every reservation and try 145 * to only reserve this buffer, then start over if 146 * this succeeds. 147 */ 148 ttm_eu_backoff_reservation_reverse(list, entry); 149 150 if (ret == -EDEADLK && intr) { 151 ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock, 152 ticket); 153 } else if (ret == -EDEADLK) { 154 ww_mutex_lock_slow(&bo->resv->lock, ticket); 155 ret = 0; 156 } 157 158 if (!ret && entry->shared) 159 ret = reservation_object_reserve_shared(bo->resv); 160 161 if (unlikely(ret != 0)) { 162 if (ret == -EINTR) 163 ret = -ERESTARTSYS; 164 if (ticket) { 165 ww_acquire_done(ticket); 166 ww_acquire_fini(ticket); 167 } 168 return ret; 169 } 170 171 /* move this item to the front of the list, 172 * forces correct iteration of the loop without keeping track 173 */ 174 list_del(&entry->head); 175 list_add(&entry->head, list); 176 } 177 178 if (ticket) 179 ww_acquire_done(ticket); 180 spin_lock(&glob->lru_lock); 181 ttm_eu_del_from_lru_locked(list); 182 spin_unlock(&glob->lru_lock); 183 return 0; 184 } 185 EXPORT_SYMBOL(ttm_eu_reserve_buffers); 186 187 void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket, 188 struct list_head *list, struct fence *fence) 189 { 190 struct ttm_validate_buffer *entry; 191 struct ttm_buffer_object *bo; 192 struct ttm_bo_global *glob; 193 struct ttm_bo_device *bdev; 194 struct ttm_bo_driver *driver __unused; 195 196 if (list_empty(list)) 197 return; 198 199 bo = list_first_entry(list, struct ttm_validate_buffer, head)->bo; 200 bdev = bo->bdev; 201 driver = bdev->driver; 202 glob = bo->glob; 203 204 spin_lock(&glob->lru_lock); 205 206 list_for_each_entry(entry, list, head) { 207 bo = entry->bo; 208 if (entry->shared) 209 reservation_object_add_shared_fence(bo->resv, fence); 210 else 211 reservation_object_add_excl_fence(bo->resv, fence); 212 ttm_bo_add_to_lru(bo); 213 __ttm_bo_unreserve(bo); 214 } 215 spin_unlock(&glob->lru_lock); 216 if (ticket) 217 ww_acquire_fini(ticket); 218 } 219 EXPORT_SYMBOL(ttm_eu_fence_buffer_objects); 220
Indexes created Tue Sep 30 11:09:46 GMT 2025