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