1 files changed, 105 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_timeline.c b/drivers/gpu/drm/i915/i915_timeline.c
new file mode 100644
index 000000000000..4667cc08c416
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_timeline.c
@@ -0,0 +1,105 @@
+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2016-2018 Intel Corporation
+ */
+
+#include "i915_drv.h"
+
+#include "i915_timeline.h"
+#include "i915_syncmap.h"
+
+void i915_timeline_init(struct drm_i915_private *i915,
+			struct i915_timeline *timeline,
+			const char *name)
+{
+	lockdep_assert_held(&i915->drm.struct_mutex);
+
+	/*
+	 * Ideally we want a set of engines on a single leaf as we expect
+	 * to mostly be tracking synchronisation between engines. It is not
+	 * a huge issue if this is not the case, but we may want to mitigate
+	 * any page crossing penalties if they become an issue.
+	 */
+	BUILD_BUG_ON(KSYNCMAP < I915_NUM_ENGINES);
+
+	timeline->name = name;
+
+	list_add(&timeline->link, &i915->gt.timelines);
+
+	/* Called during early_init before we know how many engines there are */
+
+	timeline->fence_context = dma_fence_context_alloc(1);
+
+	spin_lock_init(&timeline->lock);
+
+	init_request_active(&timeline->last_request, NULL);
+	INIT_LIST_HEAD(&timeline->requests);
+
+	i915_syncmap_init(&timeline->sync);
+}
+
+/**
+ * i915_timelines_park - called when the driver idles
+ * @i915: the drm_i915_private device
+ *
+ * When the driver is completely idle, we know that all of our sync points
+ * have been signaled and our tracking is then entirely redundant. Any request
+ * to wait upon an older sync point will be completed instantly as we know
+ * the fence is signaled and therefore we will not even look them up in the
+ * sync point map.
+ */
+void i915_timelines_park(struct drm_i915_private *i915)
+{
+	struct i915_timeline *timeline;
+
+	lockdep_assert_held(&i915->drm.struct_mutex);
+
+	list_for_each_entry(timeline, &i915->gt.timelines, link) {
+		/*
+		 * All known fences are completed so we can scrap
+		 * the current sync point tracking and start afresh,
+		 * any attempt to wait upon a previous sync point
+		 * will be skipped as the fence was signaled.
+		 */
+		i915_syncmap_free(&timeline->sync);
+	}
+}
+
+void i915_timeline_fini(struct i915_timeline *timeline)
+{
+	GEM_BUG_ON(!list_empty(&timeline->requests));
+
+	i915_syncmap_free(&timeline->sync);
+
+	list_del(&timeline->link);
+}
+
+struct i915_timeline *
+i915_timeline_create(struct drm_i915_private *i915, const char *name)
+{
+	struct i915_timeline *timeline;
+
+	timeline = kzalloc(sizeof(*timeline), GFP_KERNEL);
+	if (!timeline)
+		return ERR_PTR(-ENOMEM);
+
+	i915_timeline_init(i915, timeline, name);
+	kref_init(&timeline->kref);
+
+	return timeline;
+}
+
+void __i915_timeline_free(struct kref *kref)
+{
+	struct i915_timeline *timeline =
+		container_of(kref, typeof(*timeline), kref);
+
+	i915_timeline_fini(timeline);
+	kfree(timeline);
+}
+
+#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
+#include "selftests/mock_timeline.c"
+#include "selftests/i915_timeline.c"
+#endif