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         /* Freeing up memory requires no VMAs are pinned */
  38         if (i915_gem_obj_is_pinned(vma->obj))
  39                 return false;
  40
  41         if (WARN_ON(!list_empty(&vma->exec_list)))
  42                 return false;
  43
  44         list_add(&vma->exec_list, unwind);
  45         return drm_mm_scan_add_block(&vma->node);
  46 }
  47
  48 int
  49 i915_gem_evict_something(struct drm_device *dev, struct i915_address_space *vm,
  50                          int min_size, unsigned alignment, unsigned cache_level,
  51                          bool mappable, bool nonblocking)
  52 {
  53         drm_i915_private_t *dev_priv = dev->dev_private;
  54         struct list_head eviction_list, unwind_list;
  55         struct i915_vma *vma;
  56         int ret = 0;
  57
  58         trace_i915_gem_evict(dev, min_size, alignment, mappable);
  59
  60         /*
  61          * The goal is to evict objects and amalgamate space in LRU order.
  62          * The oldest idle objects reside on the inactive list, which is in
  63          * retirement order. The next objects to retire are those on the (per
  64          * ring) active list that do not have an outstanding flush. Once the
  65          * hardware reports completion (the seqno is updated after the
  66          * batchbuffer has been finished) the clean buffer objects would
  67          * be retired to the inactive list. Any dirty objects would be added
  68          * to the tail of the flushing list. So after processing the clean
  69          * active objects we need to emit a MI_FLUSH to retire the flushing
  70          * list, hence the retirement order of the flushing list is in
  71          * advance of the dirty objects on the active lists.
  72          *
  73          * The retirement sequence is thus:
  74          *   1. Inactive objects (already retired)
  75          *   2. Clean active objects
  76          *   3. Flushing list
  77          *   4. Dirty active objects.
  78          *
  79          * On each list, the oldest objects lie at the HEAD with the freshest
  80          * object on the TAIL.
  81          */
  82
  83         INIT_LIST_HEAD(&unwind_list);
  84         if (mappable) {
  85                 BUG_ON(!i915_is_ggtt(vm));
  86                 drm_mm_init_scan_with_range(&vm->mm, min_size,
  87                                             alignment, cache_level, 0,
  88                                             dev_priv->gtt.mappable_end);
  89         } else
  90                 drm_mm_init_scan(&vm->mm, min_size, alignment, cache_level);
  91
  92 search_again:
  93         /* First see if there is a large enough contiguous idle region... */
  94         list_for_each_entry(vma, &vm->inactive_list, mm_list) {
  95                 if (mark_free(vma, &unwind_list))
  96                         goto found;
  97         }
  98
  99         if (nonblocking)
 100                 goto none;
 101
 102         /* Now merge in the soon-to-be-expired objects... */
 103         list_for_each_entry(vma, &vm->active_list, mm_list) {
 104                 if (mark_free(vma, &unwind_list))
 105                         goto found;
 106         }
 107
 108 none:
 109         /* Nothing found, clean up and bail out! */
 110         while (!list_empty(&unwind_list)) {
 111                 vma = list_first_entry(&unwind_list,
 112                                        struct i915_vma,
 113                                        exec_list);
 114                 ret = drm_mm_scan_remove_block(&vma->node);
 115                 BUG_ON(ret);
 116
 117                 list_del_init(&vma->exec_list);
 118         }
 119
 120         /* Can we unpin some objects such as idle hw contents,
 121          * or pending flips?
 122          */
 123         ret = nonblocking ? -ENOSPC : i915_gpu_idle(dev);
 124         if (ret)
 125                 return ret;
 126
 127         /* Only idle the GPU and repeat the search once */
 128         i915_gem_retire_requests(dev);
 129         nonblocking = true;
 130         goto search_again;
 131
 132 found:
 133         /* drm_mm doesn't allow any other other operations while
 134          * scanning, therefore store to be evicted objects on a
 135          * temporary list. */
 136         INIT_LIST_HEAD(&eviction_list);
 137         while (!list_empty(&unwind_list)) {
 138                 vma = list_first_entry(&unwind_list,
 139                                        struct i915_vma,
 140                                        exec_list);
 141                 if (drm_mm_scan_remove_block(&vma->node)) {
 142                         list_move(&vma->exec_list, &eviction_list);
 143                         drm_gem_object_reference(&vma->obj->base);
 144                         continue;
 145                 }
 146                 list_del_init(&vma->exec_list);
 147         }
 148
 149         /* Unbinding will emit any required flushes */
 150         while (!list_empty(&eviction_list)) {
 151                 struct drm_gem_object *obj;
 152                 vma = list_first_entry(&eviction_list,
 153                                        struct i915_vma,
 154                                        exec_list);
 155
 156                 obj =  &vma->obj->base;
 157                 list_del_init(&vma->exec_list);
 158                 if (ret == 0)
 159                         ret = i915_vma_unbind(vma);
 160
 161                 drm_gem_object_unreference(obj);
 162         }
 163
 164         return ret;
 165 }
 166
 167 /**
 168  * i915_gem_evict_vm - Try to free up VM space
 169  *
 170  * @vm: Address space to evict from
 171  * @do_idle: Boolean directing whether to idle first.
 172  *
 173  * VM eviction is about freeing up virtual address space. If one wants fine
 174  * grained eviction, they should see evict something for more details. In terms
 175  * of freeing up actual system memory, this function may not accomplish the
 176  * desired result. An object may be shared in multiple address space, and this
 177  * function will not assert those objects be freed.
 178  *
 179  * Using do_idle will result in a more complete eviction because it retires, and
 180  * inactivates current BOs.
 181  */
 182 int i915_gem_evict_vm(struct i915_address_space *vm, bool do_idle)
 183 {
 184         struct i915_vma *vma, *next;
 185         int ret;
 186
 187         trace_i915_gem_evict_vm(vm);
 188
 189         if (do_idle) {
 190                 ret = i915_gpu_idle(vm->dev);
 191                 if (ret)
 192                         return ret;
 193
 194                 i915_gem_retire_requests(vm->dev);
 195         }
 196
 197         list_for_each_entry_safe(vma, next, &vm->inactive_list, mm_list)
 198                 if (vma->pin_count == 0)
 199                         WARN_ON(i915_vma_unbind(vma));
 200
 201         return 0;
 202 }
 203
 204 int
 205 i915_gem_evict_everything(struct drm_device *dev)
 206 {
 207         drm_i915_private_t *dev_priv = dev->dev_private;
 208         struct i915_address_space *vm;
 209         bool lists_empty = true;
 210         int ret;
 211
 212         list_for_each_entry(vm, &dev_priv->vm_list, global_link) {
 213                 lists_empty = (list_empty(&vm->inactive_list) &&
 214                                list_empty(&vm->active_list));
 215                 if (!lists_empty)
 216                         lists_empty = false;
 217         }
 218
 219         if (lists_empty)
 220                 return -ENOSPC;
 221
 222         trace_i915_gem_evict_everything(dev);
 223
 224         /* The gpu_idle will flush everything in the write domain to the
 225          * active list. Then we must move everything off the active list
 226          * with retire requests.
 227          */
 228         ret = i915_gpu_idle(dev);
 229         if (ret)
 230                 return ret;
 231
 232         i915_gem_retire_requests(dev);
 233
 234         /* Having flushed everything, unbind() should never raise an error */
 235         list_for_each_entry(vm, &dev_priv->vm_list, global_link)
 236                 WARN_ON(i915_gem_evict_vm(vm, false));
 237
 238         return 0;
 239 }