a89d1f921c
We need to move to a more flexible timeline that doesn't assume one fence context per engine, and so allow for a single timeline to be used across a combination of engines. This means that preallocating a fence context per engine is now a hindrance, and so we want to introduce the singular timeline. From the code perspective, this has the notable advantage of clearing up a lot of mirky semantics and some clumsy pointer chasing. By splitting the timeline up into a single entity rather than an array of per-engine timelines, we can realise the goal of the previous patch of tracking the timeline alongside the ring. v2: Tweak wait_for_idle to stop the compiling thinking that ret may be uninitialised. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20180502163839.3248-2-chris@chris-wilson.co.uk
106 lines
2.6 KiB
C
106 lines
2.6 KiB
C
/*
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* SPDX-License-Identifier: MIT
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*
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* Copyright © 2016-2018 Intel Corporation
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*/
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#include "i915_drv.h"
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#include "i915_timeline.h"
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#include "i915_syncmap.h"
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void i915_timeline_init(struct drm_i915_private *i915,
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struct i915_timeline *timeline,
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const char *name)
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{
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lockdep_assert_held(&i915->drm.struct_mutex);
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/*
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* Ideally we want a set of engines on a single leaf as we expect
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* to mostly be tracking synchronisation between engines. It is not
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* a huge issue if this is not the case, but we may want to mitigate
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* any page crossing penalties if they become an issue.
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*/
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BUILD_BUG_ON(KSYNCMAP < I915_NUM_ENGINES);
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timeline->name = name;
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list_add(&timeline->link, &i915->gt.timelines);
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/* Called during early_init before we know how many engines there are */
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timeline->fence_context = dma_fence_context_alloc(1);
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spin_lock_init(&timeline->lock);
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init_request_active(&timeline->last_request, NULL);
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INIT_LIST_HEAD(&timeline->requests);
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i915_syncmap_init(&timeline->sync);
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}
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/**
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* i915_timelines_park - called when the driver idles
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* @i915: the drm_i915_private device
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*
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* When the driver is completely idle, we know that all of our sync points
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* have been signaled and our tracking is then entirely redundant. Any request
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* to wait upon an older sync point will be completed instantly as we know
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* the fence is signaled and therefore we will not even look them up in the
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* sync point map.
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*/
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void i915_timelines_park(struct drm_i915_private *i915)
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{
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struct i915_timeline *timeline;
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lockdep_assert_held(&i915->drm.struct_mutex);
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list_for_each_entry(timeline, &i915->gt.timelines, link) {
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/*
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* All known fences are completed so we can scrap
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* the current sync point tracking and start afresh,
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* any attempt to wait upon a previous sync point
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* will be skipped as the fence was signaled.
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*/
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i915_syncmap_free(&timeline->sync);
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}
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}
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void i915_timeline_fini(struct i915_timeline *timeline)
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{
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GEM_BUG_ON(!list_empty(&timeline->requests));
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i915_syncmap_free(&timeline->sync);
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list_del(&timeline->link);
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}
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struct i915_timeline *
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i915_timeline_create(struct drm_i915_private *i915, const char *name)
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{
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struct i915_timeline *timeline;
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timeline = kzalloc(sizeof(*timeline), GFP_KERNEL);
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if (!timeline)
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return ERR_PTR(-ENOMEM);
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i915_timeline_init(i915, timeline, name);
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kref_init(&timeline->kref);
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return timeline;
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}
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void __i915_timeline_free(struct kref *kref)
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{
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struct i915_timeline *timeline =
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container_of(kref, typeof(*timeline), kref);
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i915_timeline_fini(timeline);
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kfree(timeline);
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}
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#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
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#include "selftests/mock_timeline.c"
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#include "selftests/i915_timeline.c"
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#endif
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