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->obj->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 int
  50 i915_gem_evict_something(struct drm_device *dev, struct i915_address_space *vm,
  51                          int min_size, unsigned alignment, unsigned cache_level,
  52                          bool mappable, bool nonblocking)
  53 {
  54         drm_i915_private_t *dev_priv = dev->dev_private;
  55         struct list_head eviction_list, unwind_list;
  56         struct i915_vma *vma;
  57         int ret = 0;
  58         int pass = 0;
  59
  60         trace_i915_gem_evict(dev, min_size, alignment, mappable);
  61
  62         /*
  63          * The goal is to evict objects and amalgamate space in LRU order.
  64          * The oldest idle objects reside on the inactive list, which is in
  65          * retirement order. The next objects to retire are those on the (per
  66          * ring) active list that do not have an outstanding flush. Once the
  67          * hardware reports completion (the seqno is updated after the
  68          * batchbuffer has been finished) the clean buffer objects would
  69          * be retired to the inactive list. Any dirty objects would be added
  70          * to the tail of the flushing list. So after processing the clean
  71          * active objects we need to emit a MI_FLUSH to retire the flushing
  72          * list, hence the retirement order of the flushing list is in
  73          * advance of the dirty objects on the active lists.
  74          *
  75          * The retirement sequence is thus:
  76          *   1. Inactive objects (already retired)
  77          *   2. Clean active objects
  78          *   3. Flushing list
  79          *   4. Dirty active objects.
  80          *
  81          * On each list, the oldest objects lie at the HEAD with the freshest
  82          * object on the TAIL.
  83          */
  84
  85         INIT_LIST_HEAD(&unwind_list);
  86         if (mappable) {
  87                 BUG_ON(!i915_is_ggtt(vm));
  88                 drm_mm_init_scan_with_range(&vm->mm, min_size,
  89                                             alignment, cache_level, 0,
  90                                             dev_priv->gtt.mappable_end);
  91         } else
  92                 drm_mm_init_scan(&vm->mm, min_size, alignment, cache_level);
  93
  94 search_again:
  95         /* First see if there is a large enough contiguous idle region... */
  96         list_for_each_entry(vma, &vm->inactive_list, mm_list) {
  97                 if (mark_free(vma, &unwind_list))
  98                         goto found;
  99         }
 100
 101         if (nonblocking)
 102                 goto none;
 103
 104         /* Now merge in the soon-to-be-expired objects... */
 105         list_for_each_entry(vma, &vm->active_list, mm_list) {
 106                 if (mark_free(vma, &unwind_list))
 107                         goto found;
 108         }
 109
 110 none:
 111         /* Nothing found, clean up and bail out! */
 112         while (!list_empty(&unwind_list)) {
 113                 vma = list_first_entry(&unwind_list,
 114                                        struct i915_vma,
 115                                        exec_list);
 116                 ret = drm_mm_scan_remove_block(&vma->node);
 117                 BUG_ON(ret);
 118
 119                 list_del_init(&vma->exec_list);
 120         }
 121
 122         /* Can we unpin some objects such as idle hw contents,
 123          * or pending flips?
 124          */
 125         if (nonblocking)
 126                 return -ENOSPC;
 127
 128         /* Only idle the GPU and repeat the search once */
 129         if (pass++ == 0) {
 130                 ret = i915_gpu_idle(dev);
 131                 if (ret)
 132                         return ret;
 133
 134                 i915_gem_retire_requests(dev);
 135                 goto search_again;
 136         }
 137
 138         /* If we still have pending pageflip completions, drop
 139          * back to userspace to give our workqueues time to
 140          * acquire our locks and unpin the old scanouts.
 141          */
 142         return intel_has_pending_fb_unpin(dev) ? -EAGAIN : -ENOSPC;
 143
 144 found:
 145         /* drm_mm doesn't allow any other other operations while
 146          * scanning, therefore store to be evicted objects on a
 147          * temporary list. */
 148         INIT_LIST_HEAD(&eviction_list);
 149         while (!list_empty(&unwind_list)) {
 150                 vma = list_first_entry(&unwind_list,
 151                                        struct i915_vma,
 152                                        exec_list);
 153                 if (drm_mm_scan_remove_block(&vma->node)) {
 154                         list_move(&vma->exec_list, &eviction_list);
 155                         drm_gem_object_reference(&vma->obj->base);
 156                         continue;
 157                 }
 158                 list_del_init(&vma->exec_list);
 159         }
 160
 161         /* Unbinding will emit any required flushes */
 162         while (!list_empty(&eviction_list)) {
 163                 struct drm_gem_object *obj;
 164                 vma = list_first_entry(&eviction_list,
 165                                        struct i915_vma,
 166                                        exec_list);
 167
 168                 obj =  &vma->obj->base;
 169                 list_del_init(&vma->exec_list);
 170                 if (ret == 0)
 171                         ret = i915_vma_unbind(vma);
 172
 173                 drm_gem_object_unreference(obj);
 174         }
 175
 176         return ret;
 177 }
 178
 179 /**
 180  * i915_gem_evict_vm - Try to free up VM space
 181  *
 182  * @vm: Address space to evict from
 183  * @do_idle: Boolean directing whether to idle first.
 184  *
 185  * VM eviction is about freeing up virtual address space. If one wants fine
 186  * grained eviction, they should see evict something for more details. In terms
 187  * of freeing up actual system memory, this function may not accomplish the
 188  * desired result. An object may be shared in multiple address space, and this
 189  * function will not assert those objects be freed.
 190  *
 191  * Using do_idle will result in a more complete eviction because it retires, and
 192  * inactivates current BOs.
 193  */
 194 int i915_gem_evict_vm(struct i915_address_space *vm, bool do_idle)
 195 {
 196         struct i915_vma *vma, *next;
 197         int ret;
 198
 199         trace_i915_gem_evict_vm(vm);
 200
 201         if (do_idle) {
 202                 ret = i915_gpu_idle(vm->dev);
 203                 if (ret)
 204                         return ret;
 205
 206                 i915_gem_retire_requests(vm->dev);
 207         }
 208
 209         list_for_each_entry_safe(vma, next, &vm->inactive_list, mm_list)
 210                 if (vma->obj->pin_count == 0)
 211                         WARN_ON(i915_vma_unbind(vma));
 212
 213         return 0;
 214 }
 215
 216 int
 217 i915_gem_evict_everything(struct drm_device *dev)
 218 {
 219         drm_i915_private_t *dev_priv = dev->dev_private;
 220         struct i915_address_space *vm;
 221         bool lists_empty = true;
 222         int ret;
 223
 224         list_for_each_entry(vm, &dev_priv->vm_list, global_link) {
 225                 lists_empty = (list_empty(&vm->inactive_list) &&
 226                                list_empty(&vm->active_list));
 227                 if (!lists_empty)
 228                         lists_empty = false;
 229         }
 230
 231         if (lists_empty)
 232                 return -ENOSPC;
 233
 234         trace_i915_gem_evict_everything(dev);
 235
 236         /* The gpu_idle will flush everything in the write domain to the
 237          * active list. Then we must move everything off the active list
 238          * with retire requests.
 239          */
 240         ret = i915_gpu_idle(dev);
 241         if (ret)
 242                 return ret;
 243
 244         i915_gem_retire_requests(dev);
 245
 246         /* Having flushed everything, unbind() should never raise an error */
 247         list_for_each_entry(vm, &dev_priv->vm_list, global_link)
 248                 WARN_ON(i915_gem_evict_vm(vm, false));
 249
 250         return 0;
 251 }