sys/dev/drm2/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 <sys/cdefs.h>
  29 __FBSDID("$FreeBSD$");
  30
  31 #include <dev/drm2/drmP.h>
  32 #include <dev/drm2/ttm/ttm_execbuf_util.h>
  33 #include <dev/drm2/ttm/ttm_bo_driver.h>
  34 #include <dev/drm2/ttm/ttm_placement.h>
  35
  36 static void ttm_eu_backoff_reservation_locked(struct list_head *list)
  37 {
  38         struct ttm_validate_buffer *entry;
  39
  40         list_for_each_entry(entry, list, head) {
  41                 struct ttm_buffer_object *bo = entry->bo;
  42                 if (!entry->reserved)
  43                         continue;
  44
  45                 if (entry->removed) {
  46                         ttm_bo_add_to_lru(bo);
  47                         entry->removed = false;
  48
  49                 }
  50                 entry->reserved = false;
  51                 atomic_set(&bo->reserved, 0);
  52                 wakeup(bo);
  53         }
  54 }
  55
  56 static void ttm_eu_del_from_lru_locked(struct list_head *list)
  57 {
  58         struct ttm_validate_buffer *entry;
  59
  60         list_for_each_entry(entry, list, head) {
  61                 struct ttm_buffer_object *bo = entry->bo;
  62                 if (!entry->reserved)
  63                         continue;
  64
  65                 if (!entry->removed) {
  66                         entry->put_count = ttm_bo_del_from_lru(bo);
  67                         entry->removed = true;
  68                 }
  69         }
  70 }
  71
  72 static void ttm_eu_list_ref_sub(struct list_head *list)
  73 {
  74         struct ttm_validate_buffer *entry;
  75
  76         list_for_each_entry(entry, list, head) {
  77                 struct ttm_buffer_object *bo = entry->bo;
  78
  79                 if (entry->put_count) {
  80                         ttm_bo_list_ref_sub(bo, entry->put_count, true);
  81                         entry->put_count = 0;
  82                 }
  83         }
  84 }
  85
  86 void ttm_eu_backoff_reservation(struct list_head *list)
  87 {
  88         struct ttm_validate_buffer *entry;
  89         struct ttm_bo_global *glob;
  90
  91         if (list_empty(list))
  92                 return;
  93
  94         entry = list_first_entry(list, struct ttm_validate_buffer, head);
  95         glob = entry->bo->glob;
  96         mtx_lock(&glob->lru_lock);
  97         ttm_eu_backoff_reservation_locked(list);
  98         mtx_unlock(&glob->lru_lock);
  99 }
 100
 101 /*
 102  * Reserve buffers for validation.
 103  *
 104  * If a buffer in the list is marked for CPU access, we back off and
 105  * wait for that buffer to become free for GPU access.
 106  *
 107  * If a buffer is reserved for another validation, the validator with
 108  * the highest validation sequence backs off and waits for that buffer
 109  * to become unreserved. This prevents deadlocks when validating multiple
 110  * buffers in different orders.
 111  */
 112
 113 int ttm_eu_reserve_buffers(struct list_head *list)
 114 {
 115         struct ttm_bo_global *glob;
 116         struct ttm_validate_buffer *entry;
 117         int ret;
 118         uint32_t val_seq;
 119
 120         if (list_empty(list))
 121                 return 0;
 122
 123         list_for_each_entry(entry, list, head) {
 124                 entry->reserved = false;
 125                 entry->put_count = 0;
 126                 entry->removed = false;
 127         }
 128
 129         entry = list_first_entry(list, struct ttm_validate_buffer, head);
 130         glob = entry->bo->glob;
 131
 132         mtx_lock(&glob->lru_lock);
 133         val_seq = entry->bo->bdev->val_seq++;
 134
 135 retry_locked:
 136         list_for_each_entry(entry, list, head) {
 137                 struct ttm_buffer_object *bo = entry->bo;
 138
 139                 /* already slowpath reserved? */
 140                 if (entry->reserved)
 141                         continue;
 142
 143                 ret = ttm_bo_reserve_nolru(bo, true, true, true, val_seq);
 144                 switch (ret) {
 145                 case 0:
 146                         break;
 147                 case -EBUSY:
 148                         ttm_eu_del_from_lru_locked(list);
 149                         ret = ttm_bo_reserve_nolru(bo, true, false,
 150                                                    true, val_seq);
 151                         if (!ret)
 152                                 break;
 153
 154                         if (unlikely(ret != -EAGAIN))
 155                                 goto err;
 156
 157                         /* fallthrough */
 158                 case -EAGAIN:
 159                         ttm_eu_backoff_reservation_locked(list);
 160
 161                         /*
 162                          * temporarily increase sequence number every retry,
 163                          * to prevent us from seeing our old reservation
 164                          * sequence when someone else reserved the buffer,
 165                          * but hasn't updated the seq_valid/seqno members yet.
 166                          */
 167                         val_seq = entry->bo->bdev->val_seq++;
 168
 169                         ttm_eu_list_ref_sub(list);
 170                         ret = ttm_bo_reserve_slowpath_nolru(bo, true, val_seq);
 171                         if (unlikely(ret != 0)) {
 172                                 mtx_unlock(&glob->lru_lock);
 173                                 return ret;
 174                         }
 175                         entry->reserved = true;
 176                         if (unlikely(atomic_read(&bo->cpu_writers) > 0)) {
 177                                 ret = -EBUSY;
 178                                 goto err;
 179                         }
 180                         goto retry_locked;
 181                 default:
 182                         goto err;
 183                 }
 184
 185                 entry->reserved = true;
 186                 if (unlikely(atomic_read(&bo->cpu_writers) > 0)) {
 187                         ret = -EBUSY;
 188                         goto err;
 189                 }
 190         }
 191
 192         ttm_eu_del_from_lru_locked(list);
 193         mtx_unlock(&glob->lru_lock);
 194         ttm_eu_list_ref_sub(list);
 195
 196         return 0;
 197
 198 err:
 199         ttm_eu_backoff_reservation_locked(list);
 200         mtx_unlock(&glob->lru_lock);
 201         ttm_eu_list_ref_sub(list);
 202         return ret;
 203 }
 204
 205 void ttm_eu_fence_buffer_objects(struct list_head *list, void *sync_obj)
 206 {
 207         struct ttm_validate_buffer *entry;
 208         struct ttm_buffer_object *bo;
 209         struct ttm_bo_global *glob;
 210         struct ttm_bo_device *bdev;
 211         struct ttm_bo_driver *driver;
 212
 213         if (list_empty(list))
 214                 return;
 215
 216         bo = list_first_entry(list, struct ttm_validate_buffer, head)->bo;
 217         bdev = bo->bdev;
 218         driver = bdev->driver;
 219         glob = bo->glob;
 220
 221         mtx_lock(&glob->lru_lock);
 222         mtx_lock(&bdev->fence_lock);
 223
 224         list_for_each_entry(entry, list, head) {
 225                 bo = entry->bo;
 226                 entry->old_sync_obj = bo->sync_obj;
 227                 bo->sync_obj = driver->sync_obj_ref(sync_obj);
 228                 ttm_bo_unreserve_locked(bo);
 229                 entry->reserved = false;
 230         }
 231         mtx_unlock(&bdev->fence_lock);
 232         mtx_unlock(&glob->lru_lock);
 233
 234         list_for_each_entry(entry, list, head) {
 235                 if (entry->old_sync_obj)
 236                         driver->sync_obj_unref(&entry->old_sync_obj);
 237         }
 238 }