drivers/gpu/drm/i915/i915_gem_evict.c

   1 /*
   2  * Copyright © 2008-2010 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  *    Eric Anholt <eric@anholt.net>
  25  *    Chris Wilson <chris@chris-wilson.co.uuk>
  26  *
  27  */
  28
  29 #include "drmP.h"
  30 #include "drm.h"
  31 #include "i915_drv.h"
  32 #include "i915_drm.h"
  33
  34 static struct drm_i915_gem_object *
  35 i915_gem_next_active_object(struct drm_device *dev,
  36                             struct list_head **render_iter,
  37                             struct list_head **bsd_iter)
  38 {
  39         drm_i915_private_t *dev_priv = dev->dev_private;
  40         struct drm_i915_gem_object *render_obj = NULL, *bsd_obj = NULL;
  41
  42         if (*render_iter != &dev_priv->render_ring.active_list)
  43                 render_obj = list_entry(*render_iter,
  44                                         struct drm_i915_gem_object,
  45                                         list);
  46
  47         if (HAS_BSD(dev)) {
  48                 if (*bsd_iter != &dev_priv->bsd_ring.active_list)
  49                         bsd_obj = list_entry(*bsd_iter,
  50                                              struct drm_i915_gem_object,
  51                                              list);
  52
  53                 if (render_obj == NULL) {
  54                         *bsd_iter = (*bsd_iter)->next;
  55                         return bsd_obj;
  56                 }
  57
  58                 if (bsd_obj == NULL) {
  59                         *render_iter = (*render_iter)->next;
  60                         return render_obj;
  61                 }
  62
  63                 /* XXX can we handle seqno wrapping? */
  64                 if (render_obj->last_rendering_seqno < bsd_obj->last_rendering_seqno) {
  65                         *render_iter = (*render_iter)->next;
  66                         return render_obj;
  67                 } else {
  68                         *bsd_iter = (*bsd_iter)->next;
  69                         return bsd_obj;
  70                 }
  71         } else {
  72                 *render_iter = (*render_iter)->next;
  73                 return render_obj;
  74         }
  75 }
  76
  77 static bool
  78 mark_free(struct drm_i915_gem_object *obj_priv,
  79            struct list_head *unwind)
  80 {
  81         list_add(&obj_priv->evict_list, unwind);
  82         return drm_mm_scan_add_block(obj_priv->gtt_space);
  83 }
  84
  85 #define i915_for_each_active_object(OBJ, R, B) \
  86         *(R) = dev_priv->render_ring.active_list.next; \
  87         *(B) = dev_priv->bsd_ring.active_list.next; \
  88         while (((OBJ) = i915_gem_next_active_object(dev, (R), (B))) != NULL)
  89
  90 int
  91 i915_gem_evict_something(struct drm_device *dev, int min_size, unsigned alignment)
  92 {
  93         drm_i915_private_t *dev_priv = dev->dev_private;
  94         struct list_head eviction_list, unwind_list;
  95         struct drm_i915_gem_object *obj_priv, *tmp_obj_priv;
  96         struct list_head *render_iter, *bsd_iter;
  97         int ret = 0;
  98
  99         i915_gem_retire_requests(dev);
 100
 101         /* Re-check for free space after retiring requests */
 102         if (drm_mm_search_free(&dev_priv->mm.gtt_space,
 103                                min_size, alignment, 0))
 104                 return 0;
 105
 106         /*
 107          * The goal is to evict objects and amalgamate space in LRU order.
 108          * The oldest idle objects reside on the inactive list, which is in
 109          * retirement order. The next objects to retire are those on the (per
 110          * ring) active list that do not have an outstanding flush. Once the
 111          * hardware reports completion (the seqno is updated after the
 112          * batchbuffer has been finished) the clean buffer objects would
 113          * be retired to the inactive list. Any dirty objects would be added
 114          * to the tail of the flushing list. So after processing the clean
 115          * active objects we need to emit a MI_FLUSH to retire the flushing
 116          * list, hence the retirement order of the flushing list is in
 117          * advance of the dirty objects on the active lists.
 118          *
 119          * The retirement sequence is thus:
 120          *   1. Inactive objects (already retired)
 121          *   2. Clean active objects
 122          *   3. Flushing list
 123          *   4. Dirty active objects.
 124          *
 125          * On each list, the oldest objects lie at the HEAD with the freshest
 126          * object on the TAIL.
 127          */
 128
 129         INIT_LIST_HEAD(&unwind_list);
 130         drm_mm_init_scan(&dev_priv->mm.gtt_space, min_size, alignment);
 131
 132         /* First see if there is a large enough contiguous idle region... */
 133         list_for_each_entry(obj_priv, &dev_priv->mm.inactive_list, list) {
 134                 if (mark_free(obj_priv, &unwind_list))
 135                         goto found;
 136         }
 137
 138         /* Now merge in the soon-to-be-expired objects... */
 139         i915_for_each_active_object(obj_priv, &render_iter, &bsd_iter) {
 140                 /* Does the object require an outstanding flush? */
 141                 if (obj_priv->base.write_domain || obj_priv->pin_count)
 142                         continue;
 143
 144                 if (mark_free(obj_priv, &unwind_list))
 145                         goto found;
 146         }
 147
 148         /* Finally add anything with a pending flush (in order of retirement) */
 149         list_for_each_entry(obj_priv, &dev_priv->mm.flushing_list, list) {
 150                 if (obj_priv->pin_count)
 151                         continue;
 152
 153                 if (mark_free(obj_priv, &unwind_list))
 154                         goto found;
 155         }
 156         i915_for_each_active_object(obj_priv, &render_iter, &bsd_iter) {
 157                 if (! obj_priv->base.write_domain || obj_priv->pin_count)
 158                         continue;
 159
 160                 if (mark_free(obj_priv, &unwind_list))
 161                         goto found;
 162         }
 163
 164         /* Nothing found, clean up and bail out! */
 165         list_for_each_entry(obj_priv, &unwind_list, evict_list) {
 166                 ret = drm_mm_scan_remove_block(obj_priv->gtt_space);
 167                 BUG_ON(ret);
 168         }
 169
 170         /* We expect the caller to unpin, evict all and try again, or give up.
 171          * So calling i915_gem_evict_everything() is unnecessary.
 172          */
 173         return -ENOSPC;
 174
 175 found:
 176         INIT_LIST_HEAD(&eviction_list);
 177         list_for_each_entry_safe(obj_priv, tmp_obj_priv,
 178                                  &unwind_list, evict_list) {
 179                 if (drm_mm_scan_remove_block(obj_priv->gtt_space)) {
 180                         /* drm_mm doesn't allow any other other operations while
 181                          * scanning, therefore store to be evicted objects on a
 182                          * temporary list. */
 183                         list_move(&obj_priv->evict_list, &eviction_list);
 184                 }
 185         }
 186
 187         /* Unbinding will emit any required flushes */
 188         list_for_each_entry_safe(obj_priv, tmp_obj_priv,
 189                                  &eviction_list, evict_list) {
 190 #if WATCH_LRU
 191                 DRM_INFO("%s: evicting %p\n", __func__, obj);
 192 #endif
 193                 ret = i915_gem_object_unbind(&obj_priv->base);
 194                 if (ret)
 195                         return ret;
 196         }
 197
 198         /* The just created free hole should be on the top of the free stack
 199          * maintained by drm_mm, so this BUG_ON actually executes in O(1).
 200          * Furthermore all accessed data has just recently been used, so it
 201          * should be really fast, too. */
 202         BUG_ON(!drm_mm_search_free(&dev_priv->mm.gtt_space, min_size,
 203                                    alignment, 0));
 204
 205         return 0;
 206 }
 207
 208 int
 209 i915_gem_evict_everything(struct drm_device *dev)
 210 {
 211         drm_i915_private_t *dev_priv = dev->dev_private;
 212         int ret;
 213         bool lists_empty;
 214
 215         spin_lock(&dev_priv->mm.active_list_lock);
 216         lists_empty = (list_empty(&dev_priv->mm.inactive_list) &&
 217                        list_empty(&dev_priv->mm.flushing_list) &&
 218                        list_empty(&dev_priv->render_ring.active_list) &&
 219                        (!HAS_BSD(dev)
 220                         || list_empty(&dev_priv->bsd_ring.active_list)));
 221         spin_unlock(&dev_priv->mm.active_list_lock);
 222
 223         if (lists_empty)
 224                 return -ENOSPC;
 225
 226         /* Flush everything (on to the inactive lists) and evict */
 227         ret = i915_gpu_idle(dev);
 228         if (ret)
 229                 return ret;
 230
 231         BUG_ON(!list_empty(&dev_priv->mm.flushing_list));
 232
 233         ret = i915_gem_evict_inactive(dev);
 234         if (ret)
 235                 return ret;
 236
 237         spin_lock(&dev_priv->mm.active_list_lock);
 238         lists_empty = (list_empty(&dev_priv->mm.inactive_list) &&
 239                        list_empty(&dev_priv->mm.flushing_list) &&
 240                        list_empty(&dev_priv->render_ring.active_list) &&
 241                        (!HAS_BSD(dev)
 242                         || list_empty(&dev_priv->bsd_ring.active_list)));
 243         spin_unlock(&dev_priv->mm.active_list_lock);
 244         BUG_ON(!lists_empty);
 245
 246         return 0;
 247 }
 248
 249 /** Unbinds all inactive objects. */
 250 int
 251 i915_gem_evict_inactive(struct drm_device *dev)
 252 {
 253         drm_i915_private_t *dev_priv = dev->dev_private;
 254
 255         while (!list_empty(&dev_priv->mm.inactive_list)) {
 256                 struct drm_gem_object *obj;
 257                 int ret;
 258
 259                 obj = &list_first_entry(&dev_priv->mm.inactive_list,
 260                                         struct drm_i915_gem_object,
 261                                         list)->base;
 262
 263                 ret = i915_gem_object_unbind(obj);
 264                 if (ret != 0) {
 265                         DRM_ERROR("Error unbinding object: %d\n", ret);
 266                         return ret;
 267                 }
 268         }
 269
 270         return 0;
 271 }