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         drm_gem_object_reference(&obj_priv->base);
  83         return drm_mm_scan_add_block(obj_priv->gtt_space);
  84 }
  85
  86 #define i915_for_each_active_object(OBJ, R, B) \
  87         *(R) = dev_priv->render_ring.active_list.next; \
  88         *(B) = dev_priv->bsd_ring.active_list.next; \
  89         while (((OBJ) = i915_gem_next_active_object(dev, (R), (B))) != NULL)
  90
  91 int
  92 i915_gem_evict_something(struct drm_device *dev, int min_size, unsigned alignment)
  93 {
  94         drm_i915_private_t *dev_priv = dev->dev_private;
  95         struct list_head eviction_list, unwind_list;
  96         struct drm_i915_gem_object *obj_priv, *tmp_obj_priv;
  97         struct list_head *render_iter, *bsd_iter;
  98         int ret = 0;
  99
 100         i915_gem_retire_requests(dev);
 101
 102         /* Re-check for free space after retiring requests */
 103         if (drm_mm_search_free(&dev_priv->mm.gtt_space,
 104                                min_size, alignment, 0))
 105                 return 0;
 106
 107         /*
 108          * The goal is to evict objects and amalgamate space in LRU order.
 109          * The oldest idle objects reside on the inactive list, which is in
 110          * retirement order. The next objects to retire are those on the (per
 111          * ring) active list that do not have an outstanding flush. Once the
 112          * hardware reports completion (the seqno is updated after the
 113          * batchbuffer has been finished) the clean buffer objects would
 114          * be retired to the inactive list. Any dirty objects would be added
 115          * to the tail of the flushing list. So after processing the clean
 116          * active objects we need to emit a MI_FLUSH to retire the flushing
 117          * list, hence the retirement order of the flushing list is in
 118          * advance of the dirty objects on the active lists.
 119          *
 120          * The retirement sequence is thus:
 121          *   1. Inactive objects (already retired)
 122          *   2. Clean active objects
 123          *   3. Flushing list
 124          *   4. Dirty active objects.
 125          *
 126          * On each list, the oldest objects lie at the HEAD with the freshest
 127          * object on the TAIL.
 128          */
 129
 130         INIT_LIST_HEAD(&unwind_list);
 131         drm_mm_init_scan(&dev_priv->mm.gtt_space, min_size, alignment);
 132
 133         /* First see if there is a large enough contiguous idle region... */
 134         list_for_each_entry(obj_priv, &dev_priv->mm.inactive_list, list) {
 135                 if (mark_free(obj_priv, &unwind_list))
 136                         goto found;
 137         }
 138
 139         /* Now merge in the soon-to-be-expired objects... */
 140         i915_for_each_active_object(obj_priv, &render_iter, &bsd_iter) {
 141                 /* Does the object require an outstanding flush? */
 142                 if (obj_priv->base.write_domain || obj_priv->pin_count)
 143                         continue;
 144
 145                 if (mark_free(obj_priv, &unwind_list))
 146                         goto found;
 147         }
 148
 149         /* Finally add anything with a pending flush (in order of retirement) */
 150         list_for_each_entry(obj_priv, &dev_priv->mm.flushing_list, list) {
 151                 if (obj_priv->pin_count)
 152                         continue;
 153
 154                 if (mark_free(obj_priv, &unwind_list))
 155                         goto found;
 156         }
 157         i915_for_each_active_object(obj_priv, &render_iter, &bsd_iter) {
 158                 if (! obj_priv->base.write_domain || obj_priv->pin_count)
 159                         continue;
 160
 161                 if (mark_free(obj_priv, &unwind_list))
 162                         goto found;
 163         }
 164
 165         /* Nothing found, clean up and bail out! */
 166         list_for_each_entry(obj_priv, &unwind_list, evict_list) {
 167                 ret = drm_mm_scan_remove_block(obj_priv->gtt_space);
 168                 BUG_ON(ret);
 169                 drm_gem_object_unreference(&obj_priv->base);
 170         }
 171
 172         /* We expect the caller to unpin, evict all and try again, or give up.
 173          * So calling i915_gem_evict_everything() is unnecessary.
 174          */
 175         return -ENOSPC;
 176
 177 found:
 178         INIT_LIST_HEAD(&eviction_list);
 179         list_for_each_entry_safe(obj_priv, tmp_obj_priv,
 180                                  &unwind_list, evict_list) {
 181                 if (drm_mm_scan_remove_block(obj_priv->gtt_space)) {
 182                         /* drm_mm doesn't allow any other other operations while
 183                          * scanning, therefore store to be evicted objects on a
 184                          * temporary list. */
 185                         list_move(&obj_priv->evict_list, &eviction_list);
 186                 } else
 187                         drm_gem_object_unreference(&obj_priv->base);
 188         }
 189
 190         /* Unbinding will emit any required flushes */
 191         list_for_each_entry_safe(obj_priv, tmp_obj_priv,
 192                                  &eviction_list, evict_list) {
 193 #if WATCH_LRU
 194                 DRM_INFO("%s: evicting %p\n", __func__, &obj_priv->base);
 195 #endif
 196                 ret = i915_gem_object_unbind(&obj_priv->base);
 197                 if (ret)
 198                         return ret;
 199
 200                 drm_gem_object_unreference(&obj_priv->base);
 201         }
 202
 203         /* The just created free hole should be on the top of the free stack
 204          * maintained by drm_mm, so this BUG_ON actually executes in O(1).
 205          * Furthermore all accessed data has just recently been used, so it
 206          * should be really fast, too. */
 207         BUG_ON(!drm_mm_search_free(&dev_priv->mm.gtt_space, min_size,
 208                                    alignment, 0));
 209
 210         return 0;
 211 }
 212
 213 int
 214 i915_gem_evict_everything(struct drm_device *dev)
 215 {
 216         drm_i915_private_t *dev_priv = dev->dev_private;
 217         int ret;
 218         bool lists_empty;
 219
 220         spin_lock(&dev_priv->mm.active_list_lock);
 221         lists_empty = (list_empty(&dev_priv->mm.inactive_list) &&
 222                        list_empty(&dev_priv->mm.flushing_list) &&
 223                        list_empty(&dev_priv->render_ring.active_list) &&
 224                        (!HAS_BSD(dev)
 225                         || list_empty(&dev_priv->bsd_ring.active_list)));
 226         spin_unlock(&dev_priv->mm.active_list_lock);
 227
 228         if (lists_empty)
 229                 return -ENOSPC;
 230
 231         /* Flush everything (on to the inactive lists) and evict */
 232         ret = i915_gpu_idle(dev);
 233         if (ret)
 234                 return ret;
 235
 236         BUG_ON(!list_empty(&dev_priv->mm.flushing_list));
 237
 238         ret = i915_gem_evict_inactive(dev);
 239         if (ret)
 240                 return ret;
 241
 242         spin_lock(&dev_priv->mm.active_list_lock);
 243         lists_empty = (list_empty(&dev_priv->mm.inactive_list) &&
 244                        list_empty(&dev_priv->mm.flushing_list) &&
 245                        list_empty(&dev_priv->render_ring.active_list) &&
 246                        (!HAS_BSD(dev)
 247                         || list_empty(&dev_priv->bsd_ring.active_list)));
 248         spin_unlock(&dev_priv->mm.active_list_lock);
 249         BUG_ON(!lists_empty);
 250
 251         return 0;
 252 }
 253
 254 /** Unbinds all inactive objects. */
 255 int
 256 i915_gem_evict_inactive(struct drm_device *dev)
 257 {
 258         drm_i915_private_t *dev_priv = dev->dev_private;
 259
 260         while (!list_empty(&dev_priv->mm.inactive_list)) {
 261                 struct drm_gem_object *obj;
 262                 int ret;
 263
 264                 obj = &list_first_entry(&dev_priv->mm.inactive_list,
 265                                         struct drm_i915_gem_object,
 266                                         list)->base;
 267
 268                 ret = i915_gem_object_unbind(obj);
 269                 if (ret != 0) {
 270                         DRM_ERROR("Error unbinding object: %d\n", ret);
 271                         return ret;
 272                 }
 273         }
 274
 275         return 0;
 276 }