drivers/gpu/drm/i915/i915_timeline.c

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright © 2016-2018 Intel Corporation
   5  */
   6
   7 #include "i915_drv.h"
   8
   9 #include "i915_timeline.h"
  10 #include "i915_syncmap.h"
  11
  12 void i915_timeline_init(struct drm_i915_private *i915,
  13                         struct i915_timeline *timeline,
  14                         const char *name)
  15 {
  16         lockdep_assert_held(&i915->drm.struct_mutex);
  17
  18         /*
  19          * Ideally we want a set of engines on a single leaf as we expect
  20          * to mostly be tracking synchronisation between engines. It is not
  21          * a huge issue if this is not the case, but we may want to mitigate
  22          * any page crossing penalties if they become an issue.
  23          */
  24         BUILD_BUG_ON(KSYNCMAP < I915_NUM_ENGINES);
  25
  26         timeline->name = name;
  27
  28         list_add(&timeline->link, &i915->gt.timelines);
  29
  30         /* Called during early_init before we know how many engines there are */
  31
  32         timeline->fence_context = dma_fence_context_alloc(1);
  33
  34         spin_lock_init(&timeline->lock);
  35
  36         init_request_active(&timeline->last_request, NULL);
  37         INIT_LIST_HEAD(&timeline->requests);
  38
  39         i915_syncmap_init(&timeline->sync);
  40 }
  41
  42 /**
  43  * i915_timelines_park - called when the driver idles
  44  * @i915: the drm_i915_private device
  45  *
  46  * When the driver is completely idle, we know that all of our sync points
  47  * have been signaled and our tracking is then entirely redundant. Any request
  48  * to wait upon an older sync point will be completed instantly as we know
  49  * the fence is signaled and therefore we will not even look them up in the
  50  * sync point map.
  51  */
  52 void i915_timelines_park(struct drm_i915_private *i915)
  53 {
  54         struct i915_timeline *timeline;
  55
  56         lockdep_assert_held(&i915->drm.struct_mutex);
  57
  58         list_for_each_entry(timeline, &i915->gt.timelines, link) {
  59                 /*
  60                  * All known fences are completed so we can scrap
  61                  * the current sync point tracking and start afresh,
  62                  * any attempt to wait upon a previous sync point
  63                  * will be skipped as the fence was signaled.
  64                  */
  65                 i915_syncmap_free(&timeline->sync);
  66         }
  67 }
  68
  69 void i915_timeline_fini(struct i915_timeline *timeline)
  70 {
  71         GEM_BUG_ON(!list_empty(&timeline->requests));
  72
  73         i915_syncmap_free(&timeline->sync);
  74
  75         list_del(&timeline->link);
  76 }
  77
  78 struct i915_timeline *
  79 i915_timeline_create(struct drm_i915_private *i915, const char *name)
  80 {
  81         struct i915_timeline *timeline;
  82
  83         timeline = kzalloc(sizeof(*timeline), GFP_KERNEL);
  84         if (!timeline)
  85                 return ERR_PTR(-ENOMEM);
  86
  87         i915_timeline_init(i915, timeline, name);
  88         kref_init(&timeline->kref);
  89
  90         return timeline;
  91 }
  92
  93 void __i915_timeline_free(struct kref *kref)
  94 {
  95         struct i915_timeline *timeline =
  96                 container_of(kref, typeof(*timeline), kref);
  97
  98         i915_timeline_fini(timeline);
  99         kfree(timeline);
 100 }
 101
 102 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
 103 #include "selftests/mock_timeline.c"
 104 #include "selftests/i915_timeline.c"
 105 #endif