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 "ttm/ttm_execbuf_util.h"
  29 #include "ttm/ttm_bo_driver.h"
  30 #include "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
 105         list_for_each_entry(entry, list, head) {
 106                 struct ttm_buffer_object *bo = entry->bo;
 107                 if (!entry->reserved)
 108                         continue;
 109
 110                 entry->reserved = false;
 111                 ttm_bo_unreserve(bo);
 112         }
 113 }
 114 EXPORT_SYMBOL(ttm_eu_backoff_reservation);
 115
 116 /*
 117  * Reserve buffers for validation.
 118  *
 119  * If a buffer in the list is marked for CPU access, we back off and
 120  * wait for that buffer to become free for GPU access.
 121  *
 122  * If a buffer is reserved for another validation, the validator with
 123  * the highest validation sequence backs off and waits for that buffer
 124  * to become unreserved. This prevents deadlocks when validating multiple
 125  * buffers in different orders.
 126  */
 127
 128 int ttm_eu_reserve_buffers(struct list_head *list, uint32_t val_seq)
 129 {
 130         struct ttm_bo_global *glob;
 131         struct ttm_validate_buffer *entry;
 132         int ret;
 133
 134         if (list_empty(list))
 135                 return 0;
 136
 137         list_for_each_entry(entry, list, head) {
 138                 entry->reserved = false;
 139                 entry->put_count = 0;
 140                 entry->removed = false;
 141         }
 142
 143         entry = list_first_entry(list, struct ttm_validate_buffer, head);
 144         glob = entry->bo->glob;
 145
 146 retry:
 147         spin_lock(&glob->lru_lock);
 148         list_for_each_entry(entry, list, head) {
 149                 struct ttm_buffer_object *bo = entry->bo;
 150
 151 retry_this_bo:
 152                 ret = ttm_bo_reserve_locked(bo, true, true, true, val_seq);
 153                 switch (ret) {
 154                 case 0:
 155                         break;
 156                 case -EBUSY:
 157                         ret = ttm_eu_wait_unreserved_locked(list, bo);
 158                         if (unlikely(ret != 0)) {
 159                                 spin_unlock(&glob->lru_lock);
 160                                 ttm_eu_list_ref_sub(list);
 161                                 return ret;
 162                         }
 163                         goto retry_this_bo;
 164                 case -EAGAIN:
 165                         ttm_eu_backoff_reservation_locked(list);
 166                         spin_unlock(&glob->lru_lock);
 167                         ttm_eu_list_ref_sub(list);
 168                         ret = ttm_bo_wait_unreserved(bo, true);
 169                         if (unlikely(ret != 0))
 170                                 return ret;
 171                         goto retry;
 172                 default:
 173                         ttm_eu_backoff_reservation_locked(list);
 174                         spin_unlock(&glob->lru_lock);
 175                         ttm_eu_list_ref_sub(list);
 176                         return ret;
 177                 }
 178
 179                 entry->reserved = true;
 180                 if (unlikely(atomic_read(&bo->cpu_writers) > 0)) {
 181                         ttm_eu_backoff_reservation_locked(list);
 182                         spin_unlock(&glob->lru_lock);
 183                         ttm_eu_list_ref_sub(list);
 184                         ret = ttm_bo_wait_cpu(bo, false);
 185                         if (ret)
 186                                 return ret;
 187                         goto retry;
 188                 }
 189         }
 190
 191         ttm_eu_del_from_lru_locked(list);
 192         spin_unlock(&glob->lru_lock);
 193         ttm_eu_list_ref_sub(list);
 194
 195         return 0;
 196 }
 197 EXPORT_SYMBOL(ttm_eu_reserve_buffers);
 198
 199 void ttm_eu_fence_buffer_objects(struct list_head *list, void *sync_obj)
 200 {
 201         struct ttm_validate_buffer *entry;
 202
 203         list_for_each_entry(entry, list, head) {
 204                 struct ttm_buffer_object *bo = entry->bo;
 205                 struct ttm_bo_driver *driver = bo->bdev->driver;
 206                 void *old_sync_obj;
 207
 208                 spin_lock(&bo->lock);
 209                 old_sync_obj = bo->sync_obj;
 210                 bo->sync_obj = driver->sync_obj_ref(sync_obj);
 211                 bo->sync_obj_arg = entry->new_sync_obj_arg;
 212                 spin_unlock(&bo->lock);
 213                 ttm_bo_unreserve(bo);
 214                 entry->reserved = false;
 215                 if (old_sync_obj)
 216                         driver->sync_obj_unref(&old_sync_obj);
 217         }
 218 }
 219 EXPORT_SYMBOL(ttm_eu_fence_buffer_objects);