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  * To clarify: This is for freeing up virtual address space, not for freeing
  67  * memory in e.g. the shrinker.
  68  */
  69 int
  70 i915_gem_evict_something(struct drm_device *dev, struct i915_address_space *vm,
  71                          int min_size, unsigned alignment, unsigned cache_level,
  72                          unsigned long start, unsigned long end,
  73                          unsigned flags)
  74 {
  75         struct list_head eviction_list, unwind_list;
  76         struct i915_vma *vma;
  77         int ret = 0;
  78         int pass = 0;
  79
  80         trace_i915_gem_evict(dev, min_size, alignment, flags);
  81
  82         /*
  83          * The goal is to evict objects and amalgamate space in LRU order.
  84          * The oldest idle objects reside on the inactive list, which is in
  85          * retirement order. The next objects to retire are those on the (per
  86          * ring) active list that do not have an outstanding flush. Once the
  87          * hardware reports completion (the seqno is updated after the
  88          * batchbuffer has been finished) the clean buffer objects would
  89          * be retired to the inactive list. Any dirty objects would be added
  90          * to the tail of the flushing list. So after processing the clean
  91          * active objects we need to emit a MI_FLUSH to retire the flushing
  92          * list, hence the retirement order of the flushing list is in
  93          * advance of the dirty objects on the active lists.
  94          *
  95          * The retirement sequence is thus:
  96          *   1. Inactive objects (already retired)
  97          *   2. Clean active objects
  98          *   3. Flushing list
  99          *   4. Dirty active objects.
 100          *
 101          * On each list, the oldest objects lie at the HEAD with the freshest
 102          * object on the TAIL.
 103          */
 104
 105         INIT_LIST_HEAD(&unwind_list);
 106         if (start != 0 || end != vm->total) {
 107                 drm_mm_init_scan_with_range(&vm->mm, min_size,
 108                                             alignment, cache_level,
 109                                             start, 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  * @vm: Address space to cleanse
 201  * @do_idle: Boolean directing whether to idle first.
 202  *
 203  * This function evicts all idles vmas from a vm. If all unpinned vmas should be
 204  * evicted the @do_idle needs to be set to true.
 205  *
 206  * This is used by the execbuf code as a last-ditch effort to defragment the
 207  * address space.
 208  *
 209  * To clarify: This is for freeing up virtual address space, not for freeing
 210  * memory in e.g. the shrinker.
 211  */
 212 int i915_gem_evict_vm(struct i915_address_space *vm, bool do_idle)
 213 {
 214         struct i915_vma *vma, *next;
 215         int ret;
 216
 217         WARN_ON(!mutex_is_locked(&vm->dev->struct_mutex));
 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                 WARN_ON(!list_empty(&vm->active_list));
 228         }
 229
 230         list_for_each_entry_safe(vma, next, &vm->inactive_list, mm_list)
 231                 if (vma->pin_count == 0)
 232                         WARN_ON(i915_vma_unbind(vma));
 233
 234         return 0;
 235 }
 236
 237 /**
 238  * i915_gem_evict_everything - Try to evict all objects
 239  * @dev: Device to evict objects for
 240  *
 241  * This functions tries to evict all gem objects from all address spaces. Used
 242  * by the shrinker as a last-ditch effort and for suspend, before releasing the
 243  * backing storage of all unbound objects.
 244  */
 245 int
 246 i915_gem_evict_everything(struct drm_device *dev)
 247 {
 248         struct drm_i915_private *dev_priv = dev->dev_private;
 249         struct i915_address_space *vm, *v;
 250         bool lists_empty = true;
 251         int ret;
 252
 253         list_for_each_entry(vm, &dev_priv->vm_list, global_link) {
 254                 lists_empty = (list_empty(&vm->inactive_list) &&
 255                                list_empty(&vm->active_list));
 256                 if (!lists_empty)
 257                         lists_empty = false;
 258         }
 259
 260         if (lists_empty)
 261                 return -ENOSPC;
 262
 263         trace_i915_gem_evict_everything(dev);
 264
 265         /* The gpu_idle will flush everything in the write domain to the
 266          * active list. Then we must move everything off the active list
 267          * with retire requests.
 268          */
 269         ret = i915_gpu_idle(dev);
 270         if (ret)
 271                 return ret;
 272
 273         i915_gem_retire_requests(dev);
 274
 275         /* Having flushed everything, unbind() should never raise an error */
 276         list_for_each_entry_safe(vm, v, &dev_priv->vm_list, global_link)
 277                 WARN_ON(i915_gem_evict_vm(vm, false));
 278
 279         return 0;
 280 }