drivers/gpu/drm/ttm/ttm_execbuf_util.c

   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);