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_locked(struct list_head *list)
  36 {
  37         struct ttm_validate_buffer *entry;
  38
  39         list_for_each_entry(entry, list, head) {
  40                 struct ttm_buffer_object *bo = entry->bo;
  41                 if (!entry->reserved)
  42                         continue;
  43
  44                 if (entry->removed) {
  45                         ttm_bo_add_to_lru(bo);
  46                         entry->removed = false;
  47
  48                 }
  49                 entry->reserved = false;
  50                 atomic_set(&bo->reserved, 0);
  51                 wake_up_all(&bo->event_queue);
  52         }
  53 }
  54
  55 static void ttm_eu_del_from_lru_locked(struct list_head *list)
  56 {
  57         struct ttm_validate_buffer *entry;
  58
  59         list_for_each_entry(entry, list, head) {
  60                 struct ttm_buffer_object *bo = entry->bo;
  61                 if (!entry->reserved)
  62                         continue;
  63
  64                 if (!entry->removed) {
  65                         entry->put_count = ttm_bo_del_from_lru(bo);
  66                         entry->removed = true;
  67                 }
  68         }
  69 }
  70
  71 static void ttm_eu_list_ref_sub(struct list_head *list)
  72 {
  73         struct ttm_validate_buffer *entry;
  74
  75         list_for_each_entry(entry, list, head) {
  76                 struct ttm_buffer_object *bo = entry->bo;
  77
  78                 if (entry->put_count) {
  79                         ttm_bo_list_ref_sub(bo, entry->put_count, true);
  80                         entry->put_count = 0;
  81                 }
  82         }
  83 }
  84
  85 static int ttm_eu_wait_unreserved_locked(struct list_head *list,
  86                                          struct ttm_buffer_object *bo)
  87 {
  88         struct ttm_bo_global *glob = bo->glob;
  89         int ret;
  90
  91         ttm_eu_del_from_lru_locked(list);
  92         spin_unlock(&glob->lru_lock);
  93         ret = ttm_bo_wait_unreserved(bo, true);
  94         spin_lock(&glob->lru_lock);
  95         if (unlikely(ret != 0))
  96                 ttm_eu_backoff_reservation_locked(list);
  97         return ret;
  98 }
  99
 100
 101 void ttm_eu_backoff_reservation(struct list_head *list)
 102 {
 103         struct ttm_validate_buffer *entry;
 104         struct ttm_bo_global *glob;
 105
 106         if (list_empty(list))
 107                 return;
 108
 109         entry = list_first_entry(list, struct ttm_validate_buffer, head);
 110         glob = entry->bo->glob;
 111         spin_lock(&glob->lru_lock);
 112         ttm_eu_backoff_reservation_locked(list);
 113         spin_unlock(&glob->lru_lock);
 114 }
 115 EXPORT_SYMBOL(ttm_eu_backoff_reservation);
 116
 117 /*
 118  * Reserve buffers for validation.
 119  *
 120  * If a buffer in the list is marked for CPU access, we back off and
 121  * wait for that buffer to become free for GPU access.
 122  *
 123  * If a buffer is reserved for another validation, the validator with
 124  * the highest validation sequence backs off and waits for that buffer
 125  * to become unreserved. This prevents deadlocks when validating multiple
 126  * buffers in different orders.
 127  */
 128
 129 int ttm_eu_reserve_buffers(struct list_head *list)
 130 {
 131         struct ttm_bo_global *glob;
 132         struct ttm_validate_buffer *entry;
 133         int ret;
 134         uint32_t val_seq;
 135
 136         if (list_empty(list))
 137                 return 0;
 138
 139         list_for_each_entry(entry, list, head) {
 140                 entry->reserved = false;
 141                 entry->put_count = 0;
 142                 entry->removed = false;
 143         }
 144
 145         entry = list_first_entry(list, struct ttm_validate_buffer, head);
 146         glob = entry->bo->glob;
 147
 148 retry:
 149         spin_lock(&glob->lru_lock);
 150         val_seq = entry->bo->bdev->val_seq++;
 151
 152         list_for_each_entry(entry, list, head) {
 153                 struct ttm_buffer_object *bo = entry->bo;
 154
 155 retry_this_bo:
 156                 ret = ttm_bo_reserve_locked(bo, true, true, true, val_seq);
 157                 switch (ret) {
 158                 case 0:
 159                         break;
 160                 case -EBUSY:
 161                         ret = ttm_eu_wait_unreserved_locked(list, bo);
 162                         if (unlikely(ret != 0)) {
 163                                 spin_unlock(&glob->lru_lock);
 164                                 ttm_eu_list_ref_sub(list);
 165                                 return ret;
 166                         }
 167                         goto retry_this_bo;
 168                 case -EAGAIN:
 169                         ttm_eu_backoff_reservation_locked(list);
 170                         spin_unlock(&glob->lru_lock);
 171                         ttm_eu_list_ref_sub(list);
 172                         ret = ttm_bo_wait_unreserved(bo, true);
 173                         if (unlikely(ret != 0))
 174                                 return ret;
 175                         goto retry;
 176                 default:
 177                         ttm_eu_backoff_reservation_locked(list);
 178                         spin_unlock(&glob->lru_lock);
 179                         ttm_eu_list_ref_sub(list);
 180                         return ret;
 181                 }
 182
 183                 entry->reserved = true;
 184                 if (unlikely(atomic_read(&bo->cpu_writers) > 0)) {
 185                         ttm_eu_backoff_reservation_locked(list);
 186                         spin_unlock(&glob->lru_lock);
 187                         ttm_eu_list_ref_sub(list);
 188                         return -EBUSY;
 189                 }
 190         }
 191
 192         ttm_eu_del_from_lru_locked(list);
 193         spin_unlock(&glob->lru_lock);
 194         ttm_eu_list_ref_sub(list);
 195
 196         return 0;
 197 }
 198 EXPORT_SYMBOL(ttm_eu_reserve_buffers);
 199
 200 void ttm_eu_fence_buffer_objects(struct list_head *list, void *sync_obj)
 201 {
 202         struct ttm_validate_buffer *entry;
 203         struct ttm_buffer_object *bo;
 204         struct ttm_bo_global *glob;
 205         struct ttm_bo_device *bdev;
 206         struct ttm_bo_driver *driver;
 207
 208         if (list_empty(list))
 209                 return;
 210
 211         bo = list_first_entry(list, struct ttm_validate_buffer, head)->bo;
 212         bdev = bo->bdev;
 213         driver = bdev->driver;
 214         glob = bo->glob;
 215
 216         spin_lock(&glob->lru_lock);
 217         spin_lock(&bdev->fence_lock);
 218
 219         list_for_each_entry(entry, list, head) {
 220                 bo = entry->bo;
 221                 entry->old_sync_obj = bo->sync_obj;
 222                 bo->sync_obj = driver->sync_obj_ref(sync_obj);
 223                 ttm_bo_unreserve_locked(bo);
 224                 entry->reserved = false;
 225         }
 226         spin_unlock(&bdev->fence_lock);
 227         spin_unlock(&glob->lru_lock);
 228
 229         list_for_each_entry(entry, list, head) {
 230                 if (entry->old_sync_obj)
 231                         driver->sync_obj_unref(&entry->old_sync_obj);
 232         }
 233 }
 234 EXPORT_SYMBOL(ttm_eu_fence_buffer_objects);