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 <drm/drmP.h>
  30 #include <drm/i915_drm.h>
  31
  32 #include "i915_drv.h"
  33 #include "intel_drv.h"
  34 #include "i915_trace.h"
  35
  36 static bool
  37 mark_free(struct i915_vma *vma, struct list_head *unwind)
  38 {
  39         if (vma->pin_count)
  40                 return false;
  41
  42         if (WARN_ON(!list_empty(&vma->exec_list)))
  43                 return false;
  44
  45         list_add(&vma->exec_list, unwind);
  46         return drm_mm_scan_add_block(&vma->node);
  47 }
  48
  49 /**
  50  * i915_gem_evict_something - Evict vmas to make room for binding a new one
  51  * @dev: drm_device
  52  * @vm: address space to evict from
  53  * @size: size of the desired free space
  54  * @alignment: alignment constraint of the desired free space
  55  * @cache_level: cache_level for the desired space
  56  * @mappable: whether the free space must be mappable
  57  * @nonblocking: whether evicting active objects is allowed or not
  58  *
  59  * This function will try to evict vmas until a free space satisfying the
  60  * requirements is found. Callers must check first whether any such hole exists
  61  * already before calling this function.
  62  *
  63  * This function is used by the object/vma binding code.
  64  *
  65  * To clarify: This is for freeing up virtual address space, not for freeing
  66  * memory in e.g. the shrinker.
  67  */
  68 int
  69 i915_gem_evict_something(struct drm_device *dev, struct i915_address_space *vm,
  70                          int min_size, unsigned alignment, unsigned cache_level,
  71                          unsigned flags)
  72 {
  73         drm_i915_private_t *dev_priv = dev->dev_private;
  74         struct list_head eviction_list, unwind_list;
  75         struct i915_vma *vma;
  76         int ret = 0;
  77         int pass = 0;
  78
  79         trace_i915_gem_evict(dev, min_size, alignment, flags);
  80
  81         /*
  82          * The goal is to evict objects and amalgamate space in LRU order.
  83          * The oldest idle objects reside on the inactive list, which is in
  84          * retirement order. The next objects to retire are those on the (per
  85          * ring) active list that do not have an outstanding flush. Once the
  86          * hardware reports completion (the seqno is updated after the
  87          * batchbuffer has been finished) the clean buffer objects would
  88          * be retired to the inactive list. Any dirty objects would be added
  89          * to the tail of the flushing list. So after processing the clean
  90          * active objects we need to emit a MI_FLUSH to retire the flushing
  91          * list, hence the retirement order of the flushing list is in
  92          * advance of the dirty objects on the active lists.
  93          *
  94          * The retirement sequence is thus:
  95          *   1. Inactive objects (already retired)
  96          *   2. Clean active objects
  97          *   3. Flushing list
  98          *   4. Dirty active objects.
  99          *
 100          * On each list, the oldest objects lie at the HEAD with the freshest
 101          * object on the TAIL.
 102          */
 103
 104         INIT_LIST_HEAD(&unwind_list);
 105         if (flags & PIN_MAPPABLE) {
 106                 BUG_ON(!i915_is_ggtt(vm));
 107                 drm_mm_init_scan_with_range(&vm->mm, min_size,
 108                                             alignment, cache_level, 0,
 109                                             dev_priv->gtt.mappable_end);
 110         } else
 111                 drm_mm_init_scan(&vm->mm, min_size, alignment, cache_level);
 112
 113 search_again:
 114         /* First see if there is a large enough contiguous idle region... */
 115         list_for_each_entry(vma, &vm->inactive_list, mm_list) {
 116                 if (mark_free(vma, &unwind_list))
 117                         goto found;
 118         }
 119
 120         if (flags & PIN_NONBLOCK)
 121                 goto none;
 122
 123         /* Now merge in the soon-to-be-expired objects... */
 124         list_for_each_entry(vma, &vm->active_list, mm_list) {
 125                 if (mark_free(vma, &unwind_list))
 126                         goto found;
 127         }
 128
 129 none:
 130         /* Nothing found, clean up and bail out! */
 131         while (!list_empty(&unwind_list)) {
 132                 vma = list_first_entry(&unwind_list,
 133                                        struct i915_vma,
 134                                        exec_list);
 135                 ret = drm_mm_scan_remove_block(&vma->node);
 136                 BUG_ON(ret);
 137
 138                 list_del_init(&vma->exec_list);
 139         }
 140
 141         /* Can we unpin some objects such as idle hw contents,
 142          * or pending flips?
 143          */
 144         if (flags & PIN_NONBLOCK)
 145                 return -ENOSPC;
 146
 147         /* Only idle the GPU and repeat the search once */
 148         if (pass++ == 0) {
 149                 ret = i915_gpu_idle(dev);
 150                 if (ret)
 151                         return ret;
 152
 153                 i915_gem_retire_requests(dev);
 154                 goto search_again;
 155         }
 156
 157         /* If we still have pending pageflip completions, drop
 158          * back to userspace to give our workqueues time to
 159          * acquire our locks and unpin the old scanouts.
 160          */
 161         return intel_has_pending_fb_unpin(dev) ? -EAGAIN : -ENOSPC;
 162
 163 found:
 164         /* drm_mm doesn't allow any other other operations while
 165          * scanning, therefore store to be evicted objects on a
 166          * temporary list. */
 167         INIT_LIST_HEAD(&eviction_list);
 168         while (!list_empty(&unwind_list)) {
 169                 vma = list_first_entry(&unwind_list,
 170                                        struct i915_vma,
 171                                        exec_list);
 172                 if (drm_mm_scan_remove_block(&vma->node)) {
 173                         list_move(&vma->exec_list, &eviction_list);
 174                         drm_gem_object_reference(&vma->obj->base);
 175                         continue;
 176                 }
 177                 list_del_init(&vma->exec_list);
 178         }
 179
 180         /* Unbinding will emit any required flushes */
 181         while (!list_empty(&eviction_list)) {
 182                 struct drm_gem_object *obj;
 183                 vma = list_first_entry(&eviction_list,
 184                                        struct i915_vma,
 185                                        exec_list);
 186
 187                 obj =  &vma->obj->base;
 188                 list_del_init(&vma->exec_list);
 189                 if (ret == 0)
 190                         ret = i915_vma_unbind(vma);
 191
 192                 drm_gem_object_unreference(obj);
 193         }
 194
 195         return ret;
 196 }
 197
 198 /**
 199  * i915_gem_evict_vm - Evict all idle vmas from a vm
 200  *
 201  * @vm: Address space to cleanse
 202  * @do_idle: Boolean directing whether to idle first.
 203  *
 204  * This function evicts all idles vmas from a vm. If all unpinned vmas should be
 205  * evicted the @do_idle needs to be set to true.
 206  *
 207  * This is used by the execbuf code as a last-ditch effort to defragment the
 208  * address space.
 209  *
 210  * To clarify: This is for freeing up virtual address space, not for freeing
 211  * memory in e.g. the shrinker.
 212  */
 213 int i915_gem_evict_vm(struct i915_address_space *vm, bool do_idle)
 214 {
 215         struct i915_vma *vma, *next;
 216         int ret;
 217
 218         trace_i915_gem_evict_vm(vm);
 219
 220         if (do_idle) {
 221                 ret = i915_gpu_idle(vm->dev);
 222                 if (ret)
 223                         return ret;
 224
 225                 i915_gem_retire_requests(vm->dev);
 226         }
 227
 228         list_for_each_entry_safe(vma, next, &vm->inactive_list, mm_list)
 229                 if (vma->pin_count == 0)
 230                         WARN_ON(i915_vma_unbind(vma));
 231
 232         return 0;
 233 }
 234
 235 /**
 236  * i915_gem_evict_everything - Try to evict all objects
 237  * @dev: Device to evict objects for
 238  *
 239  * This functions tries to evict all gem objects from all address spaces. Used
 240  * by the shrinker as a last-ditch effort and for suspend, before releasing the
 241  * backing storage of all unbound objects.
 242  */
 243 int
 244 i915_gem_evict_everything(struct drm_device *dev)
 245 {
 246         drm_i915_private_t *dev_priv = dev->dev_private;
 247         struct i915_address_space *vm;
 248         bool lists_empty = true;
 249         int ret;
 250
 251         list_for_each_entry(vm, &dev_priv->vm_list, global_link) {
 252                 lists_empty = (list_empty(&vm->inactive_list) &&
 253                                list_empty(&vm->active_list));
 254                 if (!lists_empty)
 255                         lists_empty = false;
 256         }
 257
 258         if (lists_empty)
 259                 return -ENOSPC;
 260
 261         trace_i915_gem_evict_everything(dev);
 262
 263         /* The gpu_idle will flush everything in the write domain to the
 264          * active list. Then we must move everything off the active list
 265          * with retire requests.
 266          */
 267         ret = i915_gpu_idle(dev);
 268         if (ret)
 269                 return ret;
 270
 271         i915_gem_retire_requests(dev);
 272
 273         /* Having flushed everything, unbind() should never raise an error */
 274         list_for_each_entry(vm, &dev_priv->vm_list, global_link)
 275                 WARN_ON(i915_gem_evict_vm(vm, false));
 276
 277         return 0;
 278 }