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                 __ttm_bo_unreserve(bo);
  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                 unsigned put_count = ttm_bo_del_from_lru(bo);
  52
  53                 ttm_bo_list_ref_sub(bo, put_count, true);
  54         }
  55 }
  56
  57 void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket,
  58                                 struct list_head *list)
  59 {
  60         struct ttm_validate_buffer *entry;
  61         struct ttm_bo_global *glob;
  62
  63         if (list_empty(list))
  64                 return;
  65
  66         entry = list_first_entry(list, struct ttm_validate_buffer, head);
  67         glob = entry->bo->glob;
  68
  69         spin_lock(&glob->lru_lock);
  70         list_for_each_entry(entry, list, head) {
  71                 struct ttm_buffer_object *bo = entry->bo;
  72
  73                 ttm_bo_add_to_lru(bo);
  74                 __ttm_bo_unreserve(bo);
  75         }
  76         spin_unlock(&glob->lru_lock);
  77
  78         if (ticket)
  79                 ww_acquire_fini(ticket);
  80 }
  81 EXPORT_SYMBOL(ttm_eu_backoff_reservation);
  82
  83 /*
  84  * Reserve buffers for validation.
  85  *
  86  * If a buffer in the list is marked for CPU access, we back off and
  87  * wait for that buffer to become free for GPU access.
  88  *
  89  * If a buffer is reserved for another validation, the validator with
  90  * the highest validation sequence backs off and waits for that buffer
  91  * to become unreserved. This prevents deadlocks when validating multiple
  92  * buffers in different orders.
  93  */
  94
  95 int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket,
  96                            struct list_head *list, bool intr)
  97 {
  98         struct ttm_bo_global *glob;
  99         struct ttm_validate_buffer *entry;
 100         int ret;
 101
 102         if (list_empty(list))
 103                 return 0;
 104
 105         entry = list_first_entry(list, struct ttm_validate_buffer, head);
 106         glob = entry->bo->glob;
 107
 108         if (ticket)
 109                 ww_acquire_init(ticket, &reservation_ww_class);
 110
 111         list_for_each_entry(entry, list, head) {
 112                 struct ttm_buffer_object *bo = entry->bo;
 113
 114                 ret = __ttm_bo_reserve(bo, intr, (ticket == NULL), true,
 115                                        ticket);
 116                 if (!ret && unlikely(atomic_read(&bo->cpu_writers) > 0)) {
 117                         __ttm_bo_unreserve(bo);
 118
 119                         ret = -EBUSY;
 120                 }
 121
 122                 if (!ret) {
 123                         if (!entry->shared)
 124                                 continue;
 125
 126                         ret = reservation_object_reserve_shared(bo->resv);
 127                         if (!ret)
 128                                 continue;
 129                 }
 130
 131                 /* uh oh, we lost out, drop every reservation and try
 132                  * to only reserve this buffer, then start over if
 133                  * this succeeds.
 134                  */
 135                 ttm_eu_backoff_reservation_reverse(list, entry);
 136
 137                 if (ret == -EDEADLK && intr) {
 138                         ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock,
 139                                                                ticket);
 140                 } else if (ret == -EDEADLK) {
 141                         ww_mutex_lock_slow(&bo->resv->lock, ticket);
 142                         ret = 0;
 143                 }
 144
 145                 if (!ret && entry->shared)
 146                         ret = reservation_object_reserve_shared(bo->resv);
 147
 148                 if (unlikely(ret != 0)) {
 149                         if (ret == -EINTR)
 150                                 ret = -ERESTARTSYS;
 151                         if (ticket) {
 152                                 ww_acquire_done(ticket);
 153                                 ww_acquire_fini(ticket);
 154                         }
 155                         return ret;
 156                 }
 157
 158                 /* move this item to the front of the list,
 159                  * forces correct iteration of the loop without keeping track
 160                  */
 161                 list_del(&entry->head);
 162                 list_add(&entry->head, list);
 163         }
 164
 165         if (ticket)
 166                 ww_acquire_done(ticket);
 167         spin_lock(&glob->lru_lock);
 168         ttm_eu_del_from_lru_locked(list);
 169         spin_unlock(&glob->lru_lock);
 170         return 0;
 171 }
 172 EXPORT_SYMBOL(ttm_eu_reserve_buffers);
 173
 174 void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,
 175                                  struct list_head *list, struct fence *fence)
 176 {
 177         struct ttm_validate_buffer *entry;
 178         struct ttm_buffer_object *bo;
 179         struct ttm_bo_global *glob;
 180         struct ttm_bo_device *bdev;
 181         struct ttm_bo_driver *driver;
 182
 183         if (list_empty(list))
 184                 return;
 185
 186         bo = list_first_entry(list, struct ttm_validate_buffer, head)->bo;
 187         bdev = bo->bdev;
 188         driver = bdev->driver;
 189         glob = bo->glob;
 190
 191         spin_lock(&glob->lru_lock);
 192
 193         list_for_each_entry(entry, list, head) {
 194                 bo = entry->bo;
 195                 if (entry->shared)
 196                         reservation_object_add_shared_fence(bo->resv, fence);
 197                 else
 198                         reservation_object_add_excl_fence(bo->resv, fence);
 199                 ttm_bo_add_to_lru(bo);
 200                 __ttm_bo_unreserve(bo);
 201         }
 202         spin_unlock(&glob->lru_lock);
 203         if (ticket)
 204                 ww_acquire_fini(ticket);
 205 }
 206 EXPORT_SYMBOL(ttm_eu_fence_buffer_objects);