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