sys/dev/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         lockmgr(&glob->lru_lock, LK_EXCLUSIVE);
  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         lockmgr(&glob->lru_lock, LK_RELEASE);
  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                            struct list_head *dups)
  98 {
  99         struct ttm_bo_global *glob;
 100         struct ttm_validate_buffer *entry;
 101         int ret;
 102
 103         if (list_empty(list))
 104                 return 0;
 105
 106         entry = list_first_entry(list, struct ttm_validate_buffer, head);
 107         glob = entry->bo->glob;
 108
 109         if (ticket)
 110                 ww_acquire_init(ticket, &reservation_ww_class);
 111
 112         list_for_each_entry(entry, list, head) {
 113                 struct ttm_buffer_object *bo = entry->bo;
 114
 115                 ret = __ttm_bo_reserve(bo, intr, (ticket == NULL), ticket);
 116                 if (!ret && unlikely(atomic_read(&bo->cpu_writers) > 0)) {
 117                         __ttm_bo_unreserve(bo);
 118
 119                         ret = -EBUSY;
 120
 121                 } else if (ret == -EALREADY && dups) {
 122                         struct ttm_validate_buffer *safe = entry;
 123                         entry = list_prev_entry(entry, head);
 124                         list_del(&safe->head);
 125                         list_add(&safe->head, dups);
 126                         continue;
 127                 }
 128
 129                 if (!ret) {
 130                         if (!entry->shared)
 131                                 continue;
 132
 133                         ret = reservation_object_reserve_shared(bo->resv);
 134                         if (!ret)
 135                                 continue;
 136                 }
 137
 138                 /* uh oh, we lost out, drop every reservation and try
 139                  * to only reserve this buffer, then start over if
 140                  * this succeeds.
 141                  */
 142                 ttm_eu_backoff_reservation_reverse(list, entry);
 143
 144                 if (ret == -EDEADLK && intr) {
 145                         ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock,
 146                                                                ticket);
 147                 } else if (ret == -EDEADLK) {
 148                         ww_mutex_lock_slow(&bo->resv->lock, ticket);
 149                         ret = 0;
 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         lockmgr(&glob->lru_lock, LK_EXCLUSIVE);
 175         ttm_eu_del_from_lru_locked(list);
 176         lockmgr(&glob->lru_lock, LK_RELEASE);
 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, struct fence *fence)
 183 {
 184         struct ttm_validate_buffer *entry;
 185         struct ttm_buffer_object *bo;
 186         struct ttm_bo_global *glob;
 187         struct ttm_bo_device *bdev;
 188         struct ttm_bo_driver *driver;
 189
 190         if (list_empty(list))
 191                 return;
 192
 193         bo = list_first_entry(list, struct ttm_validate_buffer, head)->bo;
 194         bdev = bo->bdev;
 195         driver = bdev->driver;
 196         glob = bo->glob;
 197
 198         lockmgr(&glob->lru_lock, LK_EXCLUSIVE);
 199
 200         list_for_each_entry(entry, list, head) {
 201                 bo = entry->bo;
 202                 if (entry->shared)
 203                         reservation_object_add_shared_fence(bo->resv, fence);
 204                 else
 205                         reservation_object_add_excl_fence(bo->resv, fence);
 206                 ttm_bo_add_to_lru(bo);
 207                 __ttm_bo_unreserve(bo);
 208         }
 209         lockmgr(&glob->lru_lock, LK_RELEASE);
 210         if (ticket)
 211                 ww_acquire_fini(ticket);
 212 }
 213 EXPORT_SYMBOL(ttm_eu_fence_buffer_objects);