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 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 reservation_object_unlock(bo->resv); 43 } 44 } 45 46 static void ttm_eu_del_from_lru_locked(struct list_head *list) 47 { 48 struct ttm_validate_buffer *entry; 49 50 list_for_each_entry(entry, list, head) { 51 struct ttm_buffer_object *bo = entry->bo; 52 ttm_bo_del_from_lru(bo); 53 } 54 } 55 56 void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket, 57 struct list_head *list) 58 { 59 struct ttm_validate_buffer *entry; 60 struct ttm_bo_global *glob; 61 62 if (list_empty(list)) 63 return; 64 65 entry = list_first_entry(list, struct ttm_validate_buffer, head); 66 glob = entry->bo->bdev->glob; 67 68 spin_lock(&glob->lru_lock); 69 list_for_each_entry(entry, list, head) { 70 struct ttm_buffer_object *bo = entry->bo; 71 72 if (list_empty(&bo->lru)) 73 ttm_bo_add_to_lru(bo); 74 reservation_object_unlock(bo->resv); 75 } 76 spin_unlock(&glob->lru_lock); 77 78 if (ticket) 79 ww_acquire_fini(ticket); 80 } 81 EXPORT_SYMBOL(ttm_eu_backoff_reservation); 82 83 /* 84 * Reserve buffers for validation. 85 * 86 * If a buffer in the list is marked for CPU access, we back off and 87 * wait for that buffer to become free for GPU access. 88 * 89 * If a buffer is reserved for another validation, the validator with 90 * the highest validation sequence backs off and waits for that buffer 91 * to become unreserved. This prevents deadlocks when validating multiple 92 * buffers in different orders. 93 */ 94 95 int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket, 96 struct list_head *list, bool intr, 97 struct list_head *dups, bool del_lru) 98 { 99 struct ttm_bo_global *glob; 100 struct ttm_validate_buffer *entry; 101 int ret; 102 103 if (list_empty(list)) 104 return 0; 105 106 entry = list_first_entry(list, struct ttm_validate_buffer, head); 107 glob = entry->bo->bdev->glob; 108 109 if (ticket) 110 ww_acquire_init(ticket, &reservation_ww_class); 111 112 list_for_each_entry(entry, list, head) { 113 struct ttm_buffer_object *bo = entry->bo; 114 115 ret = __ttm_bo_reserve(bo, intr, (ticket == NULL), ticket); 116 if (!ret && unlikely(atomic_read(&bo->cpu_writers) > 0)) { 117 reservation_object_unlock(bo->resv); 118 119 ret = -EBUSY; 120 121 } else if (ret == -EALREADY && dups) { 122 struct ttm_validate_buffer *safe = entry; 123 entry = list_prev_entry(entry, head); 124 list_del(&safe->head); 125 list_add(&safe->head, dups); 126 continue; 127 } 128 129 if (!ret) { 130 if (!entry->num_shared) 131 continue; 132 133 ret = reservation_object_reserve_shared(bo->resv, 134 entry->num_shared); 135 if (!ret) 136 continue; 137 } 138 139 /* uh oh, we lost out, drop every reservation and try 140 * to only reserve this buffer, then start over if 141 * this succeeds. 142 */ 143 ttm_eu_backoff_reservation_reverse(list, entry); 144 145 if (ret == -EDEADLK) { 146 if (intr) { 147 ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock, 148 ticket); 149 } else { 150 ww_mutex_lock_slow(&bo->resv->lock, ticket); 151 ret = 0; 152 } 153 } 154 155 if (!ret && entry->num_shared) 156 ret = reservation_object_reserve_shared(bo->resv, 157 entry->num_shared); 158 159 if (unlikely(ret != 0)) { 160 if (ret == -EINTR) 161 ret = -ERESTARTSYS; 162 if (ticket) { 163 ww_acquire_done(ticket); 164 ww_acquire_fini(ticket); 165 } 166 return ret; 167 } 168 169 /* move this item to the front of the list, 170 * forces correct iteration of the loop without keeping track 171 */ 172 list_del(&entry->head); 173 list_add(&entry->head, list); 174 } 175 176 if (del_lru) { 177 spin_lock(&glob->lru_lock); 178 ttm_eu_del_from_lru_locked(list); 179 spin_unlock(&glob->lru_lock); 180 } 181 return 0; 182 } 183 EXPORT_SYMBOL(ttm_eu_reserve_buffers); 184 185 void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket, 186 struct list_head *list, 187 struct dma_fence *fence) 188 { 189 struct ttm_validate_buffer *entry; 190 struct ttm_buffer_object *bo; 191 struct ttm_bo_global *glob; 192 193 if (list_empty(list)) 194 return; 195 196 bo = list_first_entry(list, struct ttm_validate_buffer, head)->bo; 197 glob = bo->bdev->glob; 198 199 spin_lock(&glob->lru_lock); 200 201 list_for_each_entry(entry, list, head) { 202 bo = entry->bo; 203 if (entry->num_shared) 204 reservation_object_add_shared_fence(bo->resv, fence); 205 else 206 reservation_object_add_excl_fence(bo->resv, fence); 207 if (list_empty(&bo->lru)) 208 ttm_bo_add_to_lru(bo); 209 else 210 ttm_bo_move_to_lru_tail(bo, NULL); 211 reservation_object_unlock(bo->resv); 212 } 213 spin_unlock(&glob->lru_lock); 214 if (ticket) 215 ww_acquire_fini(ticket); 216 } 217 EXPORT_SYMBOL(ttm_eu_fence_buffer_objects); 218