drivers/gpu/drm/ttm/ttm_execbuf_util.c

   1 /**************************************************************************
   2  *
   3  * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  21  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
  22  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  23  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  24  * USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28 #include <drm/ttm/ttm_execbuf_util.h>
  29 #include <drm/ttm/ttm_bo_driver.h>
  30 #include <drm/ttm/ttm_placement.h>
  31 #include <linux/wait.h>
  32 #include <linux/sched.h>
  33 #include <linux/module.h>
  34
  35 static void ttm_eu_backoff_reservation_reverse(struct list_head *list,
  36                                               struct ttm_validate_buffer *entry)
  37 {
  38         list_for_each_entry_continue_reverse(entry, list, head) {
  39                 struct ttm_buffer_object *bo = entry->bo;
  40
  41                 reservation_object_unlock(bo->resv);
  42         }
  43 }
  44
  45 static void ttm_eu_del_from_lru_locked(struct list_head *list)
  46 {
  47         struct ttm_validate_buffer *entry;
  48
  49         list_for_each_entry(entry, list, head) {
  50                 struct ttm_buffer_object *bo = entry->bo;
  51                 ttm_bo_del_from_lru(bo);
  52         }
  53 }
  54
  55 void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket,
  56                                 struct list_head *list)
  57 {
  58         struct ttm_validate_buffer *entry;
  59         struct ttm_bo_global *glob;
  60
  61         if (list_empty(list))
  62                 return;
  63
  64         entry = list_first_entry(list, struct ttm_validate_buffer, head);
  65         glob = entry->bo->bdev->glob;
  66
  67         spin_lock(&glob->lru_lock);
  68         list_for_each_entry(entry, list, head) {
  69                 struct ttm_buffer_object *bo = entry->bo;
  70
  71                 ttm_bo_add_to_lru(bo);
  72                 reservation_object_unlock(bo->resv);
  73         }
  74         spin_unlock(&glob->lru_lock);
  75
  76         if (ticket)
  77                 ww_acquire_fini(ticket);
  78 }
  79 EXPORT_SYMBOL(ttm_eu_backoff_reservation);
  80
  81 /*
  82  * Reserve buffers for validation.
  83  *
  84  * If a buffer in the list is marked for CPU access, we back off and
  85  * wait for that buffer to become free for GPU access.
  86  *
  87  * If a buffer is reserved for another validation, the validator with
  88  * the highest validation sequence backs off and waits for that buffer
  89  * to become unreserved. This prevents deadlocks when validating multiple
  90  * buffers in different orders.
  91  */
  92
  93 int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket,
  94                            struct list_head *list, bool intr,
  95                            struct list_head *dups)
  96 {
  97         struct ttm_bo_global *glob;
  98         struct ttm_validate_buffer *entry;
  99         int ret;
 100
 101         if (list_empty(list))
 102                 return 0;
 103
 104         entry = list_first_entry(list, struct ttm_validate_buffer, head);
 105         glob = entry->bo->bdev->glob;
 106
 107         if (ticket)
 108                 ww_acquire_init(ticket, &reservation_ww_class);
 109
 110         list_for_each_entry(entry, list, head) {
 111                 struct ttm_buffer_object *bo = entry->bo;
 112
 113                 ret = __ttm_bo_reserve(bo, intr, (ticket == NULL), ticket);
 114                 if (!ret && unlikely(atomic_read(&bo->cpu_writers) > 0)) {
 115                         reservation_object_unlock(bo->resv);
 116
 117                         ret = -EBUSY;
 118
 119                 } else if (ret == -EALREADY && dups) {
 120                         struct ttm_validate_buffer *safe = entry;
 121                         entry = list_prev_entry(entry, head);
 122                         list_del(&safe->head);
 123                         list_add(&safe->head, dups);
 124                         continue;
 125                 }
 126
 127                 if (!ret) {
 128                         if (!entry->shared)
 129                                 continue;
 130
 131                         ret = reservation_object_reserve_shared(bo->resv);
 132                         if (!ret)
 133                                 continue;
 134                 }
 135
 136                 /* uh oh, we lost out, drop every reservation and try
 137                  * to only reserve this buffer, then start over if
 138                  * this succeeds.
 139                  */
 140                 ttm_eu_backoff_reservation_reverse(list, entry);
 141
 142                 if (ret == -EDEADLK) {
 143                         if (intr) {
 144                                 ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock,
 145                                                                        ticket);
 146                         } else {
 147                                 ww_mutex_lock_slow(&bo->resv->lock, ticket);
 148                                 ret = 0;
 149                         }
 150                 }
 151
 152                 if (!ret && entry->shared)
 153                         ret = reservation_object_reserve_shared(bo->resv);
 154
 155                 if (unlikely(ret != 0)) {
 156                         if (ret == -EINTR)
 157                                 ret = -ERESTARTSYS;
 158                         if (ticket) {
 159                                 ww_acquire_done(ticket);
 160                                 ww_acquire_fini(ticket);
 161                         }
 162                         return ret;
 163                 }
 164
 165                 /* move this item to the front of the list,
 166                  * forces correct iteration of the loop without keeping track
 167                  */
 168                 list_del(&entry->head);
 169                 list_add(&entry->head, list);
 170         }
 171
 172         if (ticket)
 173                 ww_acquire_done(ticket);
 174         spin_lock(&glob->lru_lock);
 175         ttm_eu_del_from_lru_locked(list);
 176         spin_unlock(&glob->lru_lock);
 177         return 0;
 178 }
 179 EXPORT_SYMBOL(ttm_eu_reserve_buffers);
 180
 181 void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,
 182                                  struct list_head *list,
 183                                  struct dma_fence *fence)
 184 {
 185         struct ttm_validate_buffer *entry;
 186         struct ttm_buffer_object *bo;
 187         struct ttm_bo_global *glob;
 188         struct ttm_bo_device *bdev;
 189         struct ttm_bo_driver *driver;
 190
 191         if (list_empty(list))
 192                 return;
 193
 194         bo = list_first_entry(list, struct ttm_validate_buffer, head)->bo;
 195         bdev = bo->bdev;
 196         driver = bdev->driver;
 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->shared)
 204                         reservation_object_add_shared_fence(bo->resv, fence);
 205                 else
 206                         reservation_object_add_excl_fence(bo->resv, fence);
 207                 ttm_bo_add_to_lru(bo);
 208                 reservation_object_unlock(bo->resv);
 209         }
 210         spin_unlock(&glob->lru_lock);
 211         if (ticket)
 212                 ww_acquire_fini(ticket);
 213 }
 214 EXPORT_SYMBOL(ttm_eu_fence_buffer_objects);