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 35 static void ttm_eu_backoff_reservation_reverse(struct list_head *list, 36 struct ttm_validate_buffer *entry) 37 { 38 list_for_each_entry_continue_reverse(entry, list, head) { 39 struct ttm_buffer_object *bo = entry->bo; 40 41 __ttm_bo_unreserve(bo); 42 } 43 } 44 45 static void ttm_eu_del_from_lru_locked(struct list_head *list) 46 { 47 struct ttm_validate_buffer *entry; 48 49 list_for_each_entry(entry, list, head) { 50 struct ttm_buffer_object *bo = entry->bo; 51 ttm_bo_del_from_lru(bo); 52 } 53 } 54 55 void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket, 56 struct list_head *list) 57 { 58 struct ttm_validate_buffer *entry; 59 struct ttm_bo_global *glob; 60 61 if (list_empty(list)) 62 return; 63 64 entry = list_first_entry(list, struct ttm_validate_buffer, head); 65 glob = entry->bo->bdev->glob; 66 67 lockmgr(&glob->lru_lock, LK_EXCLUSIVE); 68 list_for_each_entry(entry, list, head) { 69 struct ttm_buffer_object *bo = entry->bo; 70 71 ttm_bo_add_to_lru(bo); 72 __ttm_bo_unreserve(bo); 73 } 74 lockmgr(&glob->lru_lock, LK_RELEASE); 75 76 if (ticket) 77 ww_acquire_fini(ticket); 78 } 79 EXPORT_SYMBOL(ttm_eu_backoff_reservation); 80 81 /* 82 * Reserve buffers for validation. 83 * 84 * If a buffer in the list is marked for CPU access, we back off and 85 * wait for that buffer to become free for GPU access. 86 * 87 * If a buffer is reserved for another validation, the validator with 88 * the highest validation sequence backs off and waits for that buffer 89 * to become unreserved. This prevents deadlocks when validating multiple 90 * buffers in different orders. 91 */ 92 93 int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket, 94 struct list_head *list, bool intr, 95 struct list_head *dups) 96 { 97 struct ttm_bo_global *glob; 98 struct ttm_validate_buffer *entry; 99 int ret; 100 101 if (list_empty(list)) 102 return 0; 103 104 entry = list_first_entry(list, struct ttm_validate_buffer, head); 105 glob = entry->bo->bdev->glob; 106 107 if (ticket) 108 ww_acquire_init(ticket, &reservation_ww_class); 109 110 list_for_each_entry(entry, list, head) { 111 struct ttm_buffer_object *bo = entry->bo; 112 113 ret = __ttm_bo_reserve(bo, intr, (ticket == NULL), ticket); 114 if (!ret && unlikely(atomic_read(&bo->cpu_writers) > 0)) { 115 __ttm_bo_unreserve(bo); 116 117 ret = -EBUSY; 118 119 } else if (ret == -EALREADY && dups) { 120 struct ttm_validate_buffer *safe = entry; 121 entry = list_prev_entry(entry, head); 122 list_del(&safe->head); 123 list_add(&safe->head, dups); 124 continue; 125 } 126 127 if (!ret) { 128 if (!entry->shared) 129 continue; 130 131 ret = reservation_object_reserve_shared(bo->resv); 132 if (!ret) 133 continue; 134 } 135 136 /* uh oh, we lost out, drop every reservation and try 137 * to only reserve this buffer, then start over if 138 * this succeeds. 139 */ 140 ttm_eu_backoff_reservation_reverse(list, entry); 141 142 if (ret == -EDEADLK && intr) { 143 ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock, 144 ticket); 145 } else if (ret == -EDEADLK) { 146 ww_mutex_lock_slow(&bo->resv->lock, ticket); 147 ret = 0; 148 } 149 150 if (!ret && entry->shared) 151 ret = reservation_object_reserve_shared(bo->resv); 152 153 if (unlikely(ret != 0)) { 154 if (ret == -EINTR) 155 ret = -ERESTARTSYS; 156 if (ticket) { 157 ww_acquire_done(ticket); 158 ww_acquire_fini(ticket); 159 } 160 return ret; 161 } 162 163 /* move this item to the front of the list, 164 * forces correct iteration of the loop without keeping track 165 */ 166 list_del(&entry->head); 167 list_add(&entry->head, list); 168 } 169 170 if (ticket) 171 ww_acquire_done(ticket); 172 lockmgr(&glob->lru_lock, LK_EXCLUSIVE); 173 ttm_eu_del_from_lru_locked(list); 174 lockmgr(&glob->lru_lock, LK_RELEASE); 175 return 0; 176 } 177 EXPORT_SYMBOL(ttm_eu_reserve_buffers); 178 179 void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket, 180 struct list_head *list, 181 struct dma_fence *fence) 182 { 183 struct ttm_validate_buffer *entry; 184 struct ttm_buffer_object *bo; 185 struct ttm_bo_global *glob; 186 struct ttm_bo_device *bdev; 187 struct ttm_bo_driver *driver; 188 189 if (list_empty(list)) 190 return; 191 192 bo = list_first_entry(list, struct ttm_validate_buffer, head)->bo; 193 bdev = bo->bdev; 194 driver = bdev->driver; 195 glob = bo->bdev->glob; 196 197 lockmgr(&glob->lru_lock, LK_EXCLUSIVE); 198 199 list_for_each_entry(entry, list, head) { 200 bo = entry->bo; 201 if (entry->shared) 202 reservation_object_add_shared_fence(bo->resv, fence); 203 else 204 reservation_object_add_excl_fence(bo->resv, fence); 205 ttm_bo_add_to_lru(bo); 206 __ttm_bo_unreserve(bo); 207 } 208 lockmgr(&glob->lru_lock, LK_RELEASE); 209 if (ticket) 210 ww_acquire_fini(ticket); 211 } 212 EXPORT_SYMBOL(ttm_eu_fence_buffer_objects); 213