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 gpu_is_idle(struct drm_i915_private *dev_priv)
  38 {
  39         struct intel_engine_cs *engine;
  40
  41         for_each_engine(engine, dev_priv) {
  42                 if (intel_engine_is_active(engine))
  43                         return false;
  44         }
  45
  46         return true;
  47 }
  48
  49 static bool
  50 mark_free(struct i915_vma *vma, unsigned int flags, struct list_head *unwind)
  51 {
  52         if (i915_vma_is_pinned(vma))
  53                 return false;
  54
  55         if (WARN_ON(!list_empty(&vma->exec_list)))
  56                 return false;
  57
  58         if (flags & PIN_NONFAULT && vma->obj->fault_mappable)
  59                 return false;
  60
  61         list_add(&vma->exec_list, unwind);
  62         return drm_mm_scan_add_block(&vma->node);
  63 }
  64
  65 /**
  66  * i915_gem_evict_something - Evict vmas to make room for binding a new one
  67  * @vm: address space to evict from
  68  * @min_size: size of the desired free space
  69  * @alignment: alignment constraint of the desired free space
  70  * @cache_level: cache_level for the desired space
  71  * @start: start (inclusive) of the range from which to evict objects
  72  * @end: end (exclusive) of the range from which to evict objects
  73  * @flags: additional flags to control the eviction algorithm
  74  *
  75  * This function will try to evict vmas until a free space satisfying the
  76  * requirements is found. Callers must check first whether any such hole exists
  77  * already before calling this function.
  78  *
  79  * This function is used by the object/vma binding code.
  80  *
  81  * Since this function is only used to free up virtual address space it only
  82  * ignores pinned vmas, and not object where the backing storage itself is
  83  * pinned. Hence obj->pages_pin_count does not protect against eviction.
  84  *
  85  * To clarify: This is for freeing up virtual address space, not for freeing
  86  * memory in e.g. the shrinker.
  87  */
  88 int
  89 i915_gem_evict_something(struct i915_address_space *vm,
  90                          u64 min_size, u64 alignment,
  91                          unsigned cache_level,
  92                          u64 start, u64 end,
  93                          unsigned flags)
  94 {
  95         struct drm_i915_private *dev_priv = to_i915(vm->dev);
  96         struct list_head eviction_list;
  97         struct list_head *phases[] = {
  98                 &vm->inactive_list,
  99                 &vm->active_list,
 100                 NULL,
 101         }, **phase;
 102         struct i915_vma *vma, *next;
 103         int ret;
 104
 105         trace_i915_gem_evict(vm, min_size, alignment, flags);
 106
 107         /*
 108          * The goal is to evict objects and amalgamate space in LRU order.
 109          * The oldest idle objects reside on the inactive list, which is in
 110          * retirement order. The next objects to retire are those in flight,
 111          * on the active list, again in retirement order.
 112          *
 113          * The retirement sequence is thus:
 114          *   1. Inactive objects (already retired)
 115          *   2. Active objects (will stall on unbinding)
 116          *
 117          * On each list, the oldest objects lie at the HEAD with the freshest
 118          * object on the TAIL.
 119          */
 120         if (start != 0 || end != vm->total) {
 121                 drm_mm_init_scan_with_range(&vm->mm, min_size,
 122                                             alignment, cache_level,
 123                                             start, end);
 124         } else
 125                 drm_mm_init_scan(&vm->mm, min_size, alignment, cache_level);
 126
 127         if (flags & PIN_NONBLOCK)
 128                 phases[1] = NULL;
 129
 130 search_again:
 131         INIT_LIST_HEAD(&eviction_list);
 132         phase = phases;
 133         do {
 134                 list_for_each_entry(vma, *phase, vm_link)
 135                         if (mark_free(vma, flags, &eviction_list))
 136                                 goto found;
 137         } while (*++phase);
 138
 139         /* Nothing found, clean up and bail out! */
 140         list_for_each_entry_safe(vma, next, &eviction_list, exec_list) {
 141                 ret = drm_mm_scan_remove_block(&vma->node);
 142                 BUG_ON(ret);
 143
 144                 INIT_LIST_HEAD(&vma->exec_list);
 145         }
 146
 147         /* Can we unpin some objects such as idle hw contents,
 148          * or pending flips? But since only the GGTT has global entries
 149          * such as scanouts, rinbuffers and contexts, we can skip the
 150          * purge when inspecting per-process local address spaces.
 151          */
 152         if (!i915_is_ggtt(vm) || flags & PIN_NONBLOCK)
 153                 return -ENOSPC;
 154
 155         if (gpu_is_idle(dev_priv)) {
 156                 /* If we still have pending pageflip completions, drop
 157                  * back to userspace to give our workqueues time to
 158                  * acquire our locks and unpin the old scanouts.
 159                  */
 160                 return intel_has_pending_fb_unpin(vm->dev) ? -EAGAIN : -ENOSPC;
 161         }
 162
 163         /* Not everything in the GGTT is tracked via vma (otherwise we
 164          * could evict as required with minimal stalling) so we are forced
 165          * to idle the GPU and explicitly retire outstanding requests in
 166          * the hopes that we can then remove contexts and the like only
 167          * bound by their active reference.
 168          */
 169         ret = i915_gem_switch_to_kernel_context(dev_priv);
 170         if (ret)
 171                 return ret;
 172
 173         ret = i915_gem_wait_for_idle(dev_priv,
 174                                      I915_WAIT_INTERRUPTIBLE |
 175                                      I915_WAIT_LOCKED);
 176         if (ret)
 177                 return ret;
 178
 179         i915_gem_retire_requests(dev_priv);
 180         goto search_again;
 181
 182 found:
 183         /* drm_mm doesn't allow any other other operations while
 184          * scanning, therefore store to-be-evicted objects on a
 185          * temporary list and take a reference for all before
 186          * calling unbind (which may remove the active reference
 187          * of any of our objects, thus corrupting the list).
 188          */
 189         list_for_each_entry_safe(vma, next, &eviction_list, exec_list) {
 190                 if (drm_mm_scan_remove_block(&vma->node))
 191                         __i915_vma_pin(vma);
 192                 else
 193                         list_del_init(&vma->exec_list);
 194         }
 195
 196         /* Unbinding will emit any required flushes */
 197         while (!list_empty(&eviction_list)) {
 198                 vma = list_first_entry(&eviction_list,
 199                                        struct i915_vma,
 200                                        exec_list);
 201
 202                 list_del_init(&vma->exec_list);
 203                 __i915_vma_unpin(vma);
 204                 if (ret == 0)
 205                         ret = i915_vma_unbind(vma);
 206         }
 207         return ret;
 208 }
 209
 210 int
 211 i915_gem_evict_for_vma(struct i915_vma *target)
 212 {
 213         struct drm_mm_node *node, *next;
 214
 215         list_for_each_entry_safe(node, next,
 216                         &target->vm->mm.head_node.node_list,
 217                         node_list) {
 218                 struct i915_vma *vma;
 219                 int ret;
 220
 221                 if (node->start + node->size <= target->node.start)
 222                         continue;
 223                 if (node->start >= target->node.start + target->node.size)
 224                         break;
 225
 226                 vma = container_of(node, typeof(*vma), node);
 227
 228                 if (i915_vma_is_pinned(vma)) {
 229                         if (!vma->exec_entry || i915_vma_pin_count(vma) > 1)
 230                                 /* Object is pinned for some other use */
 231                                 return -EBUSY;
 232
 233                         /* We need to evict a buffer in the same batch */
 234                         if (vma->exec_entry->flags & EXEC_OBJECT_PINNED)
 235                                 /* Overlapping fixed objects in the same batch */
 236                                 return -EINVAL;
 237
 238                         return -ENOSPC;
 239                 }
 240
 241                 ret = i915_vma_unbind(vma);
 242                 if (ret)
 243                         return ret;
 244         }
 245
 246         return 0;
 247 }
 248
 249 /**
 250  * i915_gem_evict_vm - Evict all idle vmas from a vm
 251  * @vm: Address space to cleanse
 252  * @do_idle: Boolean directing whether to idle first.
 253  *
 254  * This function evicts all idles vmas from a vm. If all unpinned vmas should be
 255  * evicted the @do_idle needs to be set to true.
 256  *
 257  * This is used by the execbuf code as a last-ditch effort to defragment the
 258  * address space.
 259  *
 260  * To clarify: This is for freeing up virtual address space, not for freeing
 261  * memory in e.g. the shrinker.
 262  */
 263 int i915_gem_evict_vm(struct i915_address_space *vm, bool do_idle)
 264 {
 265         struct i915_vma *vma, *next;
 266         int ret;
 267
 268         WARN_ON(!mutex_is_locked(&vm->dev->struct_mutex));
 269         trace_i915_gem_evict_vm(vm);
 270
 271         if (do_idle) {
 272                 struct drm_i915_private *dev_priv = to_i915(vm->dev);
 273
 274                 if (i915_is_ggtt(vm)) {
 275                         ret = i915_gem_switch_to_kernel_context(dev_priv);
 276                         if (ret)
 277                                 return ret;
 278                 }
 279
 280                 ret = i915_gem_wait_for_idle(dev_priv,
 281                                              I915_WAIT_INTERRUPTIBLE |
 282                                              I915_WAIT_LOCKED);
 283                 if (ret)
 284                         return ret;
 285
 286                 i915_gem_retire_requests(dev_priv);
 287                 WARN_ON(!list_empty(&vm->active_list));
 288         }
 289
 290         list_for_each_entry_safe(vma, next, &vm->inactive_list, vm_link)
 291                 if (!i915_vma_is_pinned(vma))
 292                         WARN_ON(i915_vma_unbind(vma));
 293
 294         return 0;
 295 }