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1/* SPDX-License-Identifier: GPL-2.0 OR MIT */2/**************************************************************************3 *4 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA5 * All Rights Reserved.6 *7 * Permission is hereby granted, free of charge, to any person obtaining a8 * copy of this software and associated documentation files (the9 * "Software"), to deal in the Software without restriction, including10 * without limitation the rights to use, copy, modify, merge, publish,11 * distribute, sub license, and/or sell copies of the Software, and to12 * permit persons to whom the Software is furnished to do so, subject to13 * the following conditions:14 *15 * The above copyright notice and this permission notice (including the16 * next paragraph) shall be included in all copies or substantial portions17 * of the Software.18 *19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,21 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL22 * 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 OR24 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE25 * USE OR OTHER DEALINGS IN THE SOFTWARE.26 *27 **************************************************************************/28 29#include <drm/ttm/ttm_execbuf_util.h>30#include <drm/ttm/ttm_bo.h>31 32static void ttm_eu_backoff_reservation_reverse(struct list_head *list,33 struct ttm_validate_buffer *entry)34{35 list_for_each_entry_continue_reverse(entry, list, head) {36 struct ttm_buffer_object *bo = entry->bo;37 38 dma_resv_unlock(bo->base.resv);39 }40}41 42void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket,43 struct list_head *list)44{45 struct ttm_validate_buffer *entry;46 47 if (list_empty(list))48 return;49 50 list_for_each_entry(entry, list, head) {51 struct ttm_buffer_object *bo = entry->bo;52 53 ttm_bo_move_to_lru_tail_unlocked(bo);54 dma_resv_unlock(bo->base.resv);55 }56 57 if (ticket)58 ww_acquire_fini(ticket);59}60EXPORT_SYMBOL(ttm_eu_backoff_reservation);61 62/*63 * Reserve buffers for validation.64 *65 * If a buffer in the list is marked for CPU access, we back off and66 * wait for that buffer to become free for GPU access.67 *68 * If a buffer is reserved for another validation, the validator with69 * the highest validation sequence backs off and waits for that buffer70 * to become unreserved. This prevents deadlocks when validating multiple71 * buffers in different orders.72 */73 74int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket,75 struct list_head *list, bool intr,76 struct list_head *dups)77{78 struct ttm_validate_buffer *entry;79 int ret;80 81 if (list_empty(list))82 return 0;83 84 if (ticket)85 ww_acquire_init(ticket, &reservation_ww_class);86 87 list_for_each_entry(entry, list, head) {88 struct ttm_buffer_object *bo = entry->bo;89 unsigned int num_fences;90 91 ret = ttm_bo_reserve(bo, intr, (ticket == NULL), ticket);92 if (ret == -EALREADY && dups) {93 struct ttm_validate_buffer *safe = entry;94 entry = list_prev_entry(entry, head);95 list_del(&safe->head);96 list_add(&safe->head, dups);97 continue;98 }99 100 num_fences = max(entry->num_shared, 1u);101 if (!ret) {102 ret = dma_resv_reserve_fences(bo->base.resv,103 num_fences);104 if (!ret)105 continue;106 }107 108 /* uh oh, we lost out, drop every reservation and try109 * to only reserve this buffer, then start over if110 * this succeeds.111 */112 ttm_eu_backoff_reservation_reverse(list, entry);113 114 if (ret == -EDEADLK) {115 ret = ttm_bo_reserve_slowpath(bo, intr, ticket);116 }117 118 if (!ret)119 ret = dma_resv_reserve_fences(bo->base.resv,120 num_fences);121 122 if (unlikely(ret != 0)) {123 if (ticket) {124 ww_acquire_done(ticket);125 ww_acquire_fini(ticket);126 }127 return ret;128 }129 130 /* move this item to the front of the list,131 * forces correct iteration of the loop without keeping track132 */133 list_del(&entry->head);134 list_add(&entry->head, list);135 }136 137 return 0;138}139EXPORT_SYMBOL(ttm_eu_reserve_buffers);140 141void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,142 struct list_head *list,143 struct dma_fence *fence)144{145 struct ttm_validate_buffer *entry;146 147 if (list_empty(list))148 return;149 150 list_for_each_entry(entry, list, head) {151 struct ttm_buffer_object *bo = entry->bo;152 153 dma_resv_add_fence(bo->base.resv, fence, entry->num_shared ?154 DMA_RESV_USAGE_READ : DMA_RESV_USAGE_WRITE);155 ttm_bo_move_to_lru_tail_unlocked(bo);156 dma_resv_unlock(bo->base.resv);157 }158 if (ticket)159 ww_acquire_fini(ticket);160}161EXPORT_SYMBOL(ttm_eu_fence_buffer_objects);162