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 "i915_drv.h"
  31 #include <drm/i915_drm.h>
  32 #include "i915_trace.h"
  33
  34 static bool
  35 mark_free(struct i915_vma *vma, struct list_head *unwind)
  36 {
  37         if (vma->obj->pin_count)
  38                 return false;
  39
  40         if (WARN_ON(!list_empty(&vma->exec_list)))
  41                 return false;
  42
  43         list_add(&vma->exec_list, unwind);
  44         return drm_mm_scan_add_block(&vma->node);
  45 }
  46
  47 int
  48 i915_gem_evict_something(struct drm_device *dev, struct i915_address_space *vm,
  49                          int min_size, unsigned alignment, unsigned cache_level,
  50                          bool mappable, bool nonblocking)
  51 {
  52         drm_i915_private_t *dev_priv = dev->dev_private;
  53         struct list_head eviction_list, unwind_list;
  54         struct i915_vma *vma;
  55         int ret = 0;
  56
  57         trace_i915_gem_evict(dev, min_size, alignment, mappable);
  58
  59         /*
  60          * The goal is to evict objects and amalgamate space in LRU order.
  61          * The oldest idle objects reside on the inactive list, which is in
  62          * retirement order. The next objects to retire are those on the (per
  63          * ring) active list that do not have an outstanding flush. Once the
  64          * hardware reports completion (the seqno is updated after the
  65          * batchbuffer has been finished) the clean buffer objects would
  66          * be retired to the inactive list. Any dirty objects would be added
  67          * to the tail of the flushing list. So after processing the clean
  68          * active objects we need to emit a MI_FLUSH to retire the flushing
  69          * list, hence the retirement order of the flushing list is in
  70          * advance of the dirty objects on the active lists.
  71          *
  72          * The retirement sequence is thus:
  73          *   1. Inactive objects (already retired)
  74          *   2. Clean active objects
  75          *   3. Flushing list
  76          *   4. Dirty active objects.
  77          *
  78          * On each list, the oldest objects lie at the HEAD with the freshest
  79          * object on the TAIL.
  80          */
  81
  82         INIT_LIST_HEAD(&unwind_list);
  83         if (mappable) {
  84                 BUG_ON(!i915_is_ggtt(vm));
  85                 drm_mm_init_scan_with_range(&vm->mm, min_size,
  86                                             alignment, cache_level, 0,
  87                                             dev_priv->gtt.mappable_end);
  88         } else
  89                 drm_mm_init_scan(&vm->mm, min_size, alignment, cache_level);
  90
  91 search_again:
  92         /* First see if there is a large enough contiguous idle region... */
  93         list_for_each_entry(vma, &vm->inactive_list, mm_list) {
  94                 if (mark_free(vma, &unwind_list))
  95                         goto found;
  96         }
  97
  98         if (nonblocking)
  99                 goto none;
 100
 101         /* Now merge in the soon-to-be-expired objects... */
 102         list_for_each_entry(vma, &vm->active_list, mm_list) {
 103                 if (mark_free(vma, &unwind_list))
 104                         goto found;
 105         }
 106
 107 none:
 108         /* Nothing found, clean up and bail out! */
 109         while (!list_empty(&unwind_list)) {
 110                 vma = list_first_entry(&unwind_list,
 111                                        struct i915_vma,
 112                                        exec_list);
 113                 ret = drm_mm_scan_remove_block(&vma->node);
 114                 BUG_ON(ret);
 115
 116                 list_del_init(&vma->exec_list);
 117         }
 118
 119         /* Can we unpin some objects such as idle hw contents,
 120          * or pending flips?
 121          */
 122         ret = nonblocking ? -ENOSPC : i915_gpu_idle(dev);
 123         if (ret)
 124                 return ret;
 125
 126         /* Only idle the GPU and repeat the search once */
 127         i915_gem_retire_requests(dev);
 128         nonblocking = true;
 129         goto search_again;
 130
 131 found:
 132         /* drm_mm doesn't allow any other other operations while
 133          * scanning, therefore store to be evicted objects on a
 134          * temporary list. */
 135         INIT_LIST_HEAD(&eviction_list);
 136         while (!list_empty(&unwind_list)) {
 137                 vma = list_first_entry(&unwind_list,
 138                                        struct i915_vma,
 139                                        exec_list);
 140                 if (drm_mm_scan_remove_block(&vma->node)) {
 141                         list_move(&vma->exec_list, &eviction_list);
 142                         drm_gem_object_reference(&vma->obj->base);
 143                         continue;
 144                 }
 145                 list_del_init(&vma->exec_list);
 146         }
 147
 148         /* Unbinding will emit any required flushes */
 149         while (!list_empty(&eviction_list)) {
 150                 struct drm_gem_object *obj;
 151                 vma = list_first_entry(&eviction_list,
 152                                        struct i915_vma,
 153                                        exec_list);
 154
 155                 obj =  &vma->obj->base;
 156                 list_del_init(&vma->exec_list);
 157                 if (ret == 0)
 158                         ret = i915_vma_unbind(vma);
 159
 160                 drm_gem_object_unreference(obj);
 161         }
 162
 163         return ret;
 164 }
 165
 166 /**
 167  * i915_gem_evict_vm - Try to free up VM space
 168  *
 169  * @vm: Address space to evict from
 170  * @do_idle: Boolean directing whether to idle first.
 171  *
 172  * VM eviction is about freeing up virtual address space. If one wants fine
 173  * grained eviction, they should see evict something for more details. In terms
 174  * of freeing up actual system memory, this function may not accomplish the
 175  * desired result. An object may be shared in multiple address space, and this
 176  * function will not assert those objects be freed.
 177  *
 178  * Using do_idle will result in a more complete eviction because it retires, and
 179  * inactivates current BOs.
 180  */
 181 int i915_gem_evict_vm(struct i915_address_space *vm, bool do_idle)
 182 {
 183         struct i915_vma *vma, *next;
 184         int ret;
 185
 186         trace_i915_gem_evict_vm(vm);
 187
 188         if (do_idle) {
 189                 ret = i915_gpu_idle(vm->dev);
 190                 if (ret)
 191                         return ret;
 192
 193                 i915_gem_retire_requests(vm->dev);
 194         }
 195
 196         list_for_each_entry_safe(vma, next, &vm->inactive_list, mm_list)
 197                 if (vma->obj->pin_count == 0)
 198                         WARN_ON(i915_vma_unbind(vma));
 199
 200         return 0;
 201 }
 202
 203 int
 204 i915_gem_evict_everything(struct drm_device *dev)
 205 {
 206         drm_i915_private_t *dev_priv = dev->dev_private;
 207         struct i915_address_space *vm;
 208         bool lists_empty = true;
 209         int ret;
 210
 211         list_for_each_entry(vm, &dev_priv->vm_list, global_link) {
 212                 lists_empty = (list_empty(&vm->inactive_list) &&
 213                                list_empty(&vm->active_list));
 214                 if (!lists_empty)
 215                         lists_empty = false;
 216         }
 217
 218         if (lists_empty)
 219                 return -ENOSPC;
 220
 221         trace_i915_gem_evict_everything(dev);
 222
 223         /* The gpu_idle will flush everything in the write domain to the
 224          * active list. Then we must move everything off the active list
 225          * with retire requests.
 226          */
 227         ret = i915_gpu_idle(dev);
 228         if (ret)
 229                 return ret;
 230
 231         i915_gem_retire_requests(dev);
 232
 233         /* Having flushed everything, unbind() should never raise an error */
 234         list_for_each_entry(vm, &dev_priv->vm_list, global_link)
 235                 WARN_ON(i915_gem_evict_vm(vm, false));
 236
 237         return 0;
 238 }