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  * @min_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  * @start: start (inclusive) of the range from which to evict objects
  57  * @end: end (exclusive) of the range from which to evict objects
  58  * @flags: additional flags to control the eviction algorithm
  59  *
  60  * This function will try to evict vmas until a free space satisfying the
  61  * requirements is found. Callers must check first whether any such hole exists
  62  * already before calling this function.
  63  *
  64  * This function is used by the object/vma binding code.
  65  *
  66  * Since this function is only used to free up virtual address space it only
  67  * ignores pinned vmas, and not object where the backing storage itself is
  68  * pinned. Hence obj->pages_pin_count does not protect against eviction.
  69  *
  70  * To clarify: This is for freeing up virtual address space, not for freeing
  71  * memory in e.g. the shrinker.
  72  */
  73 int
  74 i915_gem_evict_something(struct drm_device *dev, struct i915_address_space *vm,
  75                          int min_size, unsigned alignment, unsigned cache_level,
  76                          unsigned long start, unsigned long end,
  77                          unsigned flags)
  78 {
  79         struct list_head eviction_list, unwind_list;
  80         struct i915_vma *vma;
  81         int ret = 0;
  82         int pass = 0;
  83
  84         trace_i915_gem_evict(dev, min_size, alignment, flags);
  85
  86         /*
  87          * The goal is to evict objects and amalgamate space in LRU order.
  88          * The oldest idle objects reside on the inactive list, which is in
  89          * retirement order. The next objects to retire are those on the (per
  90          * ring) active list that do not have an outstanding flush. Once the
  91          * hardware reports completion (the seqno is updated after the
  92          * batchbuffer has been finished) the clean buffer objects would
  93          * be retired to the inactive list. Any dirty objects would be added
  94          * to the tail of the flushing list. So after processing the clean
  95          * active objects we need to emit a MI_FLUSH to retire the flushing
  96          * list, hence the retirement order of the flushing list is in
  97          * advance of the dirty objects on the active lists.
  98          *
  99          * The retirement sequence is thus:
 100          *   1. Inactive objects (already retired)
 101          *   2. Clean active objects
 102          *   3. Flushing list
 103          *   4. Dirty active objects.
 104          *
 105          * On each list, the oldest objects lie at the HEAD with the freshest
 106          * object on the TAIL.
 107          */
 108
 109         INIT_LIST_HEAD(&unwind_list);
 110         if (start != 0 || end != vm->total) {
 111                 drm_mm_init_scan_with_range(&vm->mm, min_size,
 112                                             alignment, cache_level,
 113                                             start, end);
 114         } else
 115                 drm_mm_init_scan(&vm->mm, min_size, alignment, cache_level);
 116
 117 search_again:
 118         /* First see if there is a large enough contiguous idle region... */
 119         list_for_each_entry(vma, &vm->inactive_list, vm_link) {
 120                 if (mark_free(vma, &unwind_list))
 121                         goto found;
 122         }
 123
 124         if (flags & PIN_NONBLOCK)
 125                 goto none;
 126
 127         /* Now merge in the soon-to-be-expired objects... */
 128         list_for_each_entry(vma, &vm->active_list, vm_link) {
 129                 if (mark_free(vma, &unwind_list))
 130                         goto found;
 131         }
 132
 133 none:
 134         /* Nothing found, clean up and bail out! */
 135         while (!list_empty(&unwind_list)) {
 136                 vma = list_first_entry(&unwind_list,
 137                                        struct i915_vma,
 138                                        exec_list);
 139                 ret = drm_mm_scan_remove_block(&vma->node);
 140                 BUG_ON(ret);
 141
 142                 list_del_init(&vma->exec_list);
 143         }
 144
 145         /* Can we unpin some objects such as idle hw contents,
 146          * or pending flips?
 147          */
 148         if (flags & PIN_NONBLOCK)
 149                 return -ENOSPC;
 150
 151         /* Only idle the GPU and repeat the search once */
 152         if (pass++ == 0) {
 153                 ret = i915_gpu_idle(dev);
 154                 if (ret)
 155                         return ret;
 156
 157                 i915_gem_retire_requests(dev);
 158                 goto search_again;
 159         }
 160
 161         /* If we still have pending pageflip completions, drop
 162          * back to userspace to give our workqueues time to
 163          * acquire our locks and unpin the old scanouts.
 164          */
 165         return intel_has_pending_fb_unpin(dev) ? -EAGAIN : -ENOSPC;
 166
 167 found:
 168         /* drm_mm doesn't allow any other other operations while
 169          * scanning, therefore store to be evicted objects on a
 170          * temporary list. */
 171         INIT_LIST_HEAD(&eviction_list);
 172         while (!list_empty(&unwind_list)) {
 173                 vma = list_first_entry(&unwind_list,
 174                                        struct i915_vma,
 175                                        exec_list);
 176                 if (drm_mm_scan_remove_block(&vma->node)) {
 177                         list_move(&vma->exec_list, &eviction_list);
 178                         drm_gem_object_reference(&vma->obj->base);
 179                         continue;
 180                 }
 181                 list_del_init(&vma->exec_list);
 182         }
 183
 184         /* Unbinding will emit any required flushes */
 185         while (!list_empty(&eviction_list)) {
 186                 struct drm_gem_object *obj;
 187                 vma = list_first_entry(&eviction_list,
 188                                        struct i915_vma,
 189                                        exec_list);
 190
 191                 obj =  &vma->obj->base;
 192                 list_del_init(&vma->exec_list);
 193                 if (ret == 0)
 194                         ret = i915_vma_unbind(vma);
 195
 196                 drm_gem_object_unreference(obj);
 197         }
 198
 199         return ret;
 200 }
 201
 202 int
 203 i915_gem_evict_for_vma(struct i915_vma *target)
 204 {
 205         struct drm_mm_node *node, *next;
 206
 207         list_for_each_entry_safe(node, next,
 208                         &target->vm->mm.head_node.node_list,
 209                         node_list) {
 210                 struct i915_vma *vma;
 211                 int ret;
 212
 213                 if (node->start + node->size <= target->node.start)
 214                         continue;
 215                 if (node->start >= target->node.start + target->node.size)
 216                         break;
 217
 218                 vma = container_of(node, typeof(*vma), node);
 219
 220                 if (vma->pin_count) {
 221                         if (!vma->exec_entry || (vma->pin_count > 1))
 222                                 /* Object is pinned for some other use */
 223                                 return -EBUSY;
 224
 225                         /* We need to evict a buffer in the same batch */
 226                         if (vma->exec_entry->flags & EXEC_OBJECT_PINNED)
 227                                 /* Overlapping fixed objects in the same batch */
 228                                 return -EINVAL;
 229
 230                         return -ENOSPC;
 231                 }
 232
 233                 ret = i915_vma_unbind(vma);
 234                 if (ret)
 235                         return ret;
 236         }
 237
 238         return 0;
 239 }
 240
 241 /**
 242  * i915_gem_evict_vm - Evict all idle vmas from a vm
 243  * @vm: Address space to cleanse
 244  * @do_idle: Boolean directing whether to idle first.
 245  *
 246  * This function evicts all idles vmas from a vm. If all unpinned vmas should be
 247  * evicted the @do_idle needs to be set to true.
 248  *
 249  * This is used by the execbuf code as a last-ditch effort to defragment the
 250  * address space.
 251  *
 252  * To clarify: This is for freeing up virtual address space, not for freeing
 253  * memory in e.g. the shrinker.
 254  */
 255 int i915_gem_evict_vm(struct i915_address_space *vm, bool do_idle)
 256 {
 257         struct i915_vma *vma, *next;
 258         int ret;
 259
 260         WARN_ON(!mutex_is_locked(&vm->dev->struct_mutex));
 261         trace_i915_gem_evict_vm(vm);
 262
 263         if (do_idle) {
 264                 ret = i915_gpu_idle(vm->dev);
 265                 if (ret)
 266                         return ret;
 267
 268                 i915_gem_retire_requests(vm->dev);
 269
 270                 WARN_ON(!list_empty(&vm->active_list));
 271         }
 272
 273         list_for_each_entry_safe(vma, next, &vm->inactive_list, vm_link)
 274                 if (vma->pin_count == 0)
 275                         WARN_ON(i915_vma_unbind(vma));
 276
 277         return 0;
 278 }