[PATCH v2 4/5] drm/scheduler: Add fence deadline support

[Rob Clark]

From: Rob Clark <robdclark at chromium.org>

As the finished fence is the one that is exposed to userspace, and
therefore the one that other operations, like atomic update, would
block on, we need to propagate the deadline from from the finished
fence to the actual hw fence.

Signed-off-by: Rob Clark <robdclark at chromium.org>
---
 drivers/gpu/drm/scheduler/sched_fence.c | 25 +++++++++++++++++++++++++
 drivers/gpu/drm/scheduler/sched_main.c  |  3 +++
 include/drm/gpu_scheduler.h             |  6 ++++++
 3 files changed, 34 insertions(+)

diff --git a/drivers/gpu/drm/scheduler/sched_fence.c b/drivers/gpu/drm/scheduler/sched_fence.c
index 69de2c76731f..f389dca44185 100644
--- a/drivers/gpu/drm/scheduler/sched_fence.c
+++ b/drivers/gpu/drm/scheduler/sched_fence.c
@@ -128,6 +128,30 @@ static void drm_sched_fence_release_finished(struct dma_fence *f)
 	dma_fence_put(&fence->scheduled);
 }
 
+static void drm_sched_fence_set_deadline_finished(struct dma_fence *f,
+						  ktime_t deadline)
+{
+	struct drm_sched_fence *fence = to_drm_sched_fence(f);
+	unsigned long flags;
+
+	spin_lock_irqsave(&fence->lock, flags);
+
+	/* If we already have an earlier deadline, keep it: */
+	if (test_bit(DMA_FENCE_FLAG_HAS_DEADLINE_BIT, &f->flags) &&
+	    ktime_before(fence->deadline, deadline)) {
+		spin_unlock_irqrestore(&fence->lock, flags);
+		return;
+	}
+
+	fence->deadline = deadline;
+	set_bit(DMA_FENCE_FLAG_HAS_DEADLINE_BIT, &f->flags);
+
+	spin_unlock_irqrestore(&fence->lock, flags);
+
+	if (fence->parent)
+		dma_fence_set_deadline(fence->parent, deadline);
+}
+
 static const struct dma_fence_ops drm_sched_fence_ops_scheduled = {
 	.get_driver_name = drm_sched_fence_get_driver_name,
 	.get_timeline_name = drm_sched_fence_get_timeline_name,
@@ -138,6 +162,7 @@ static const struct dma_fence_ops drm_sched_fence_ops_finished = {
 	.get_driver_name = drm_sched_fence_get_driver_name,
 	.get_timeline_name = drm_sched_fence_get_timeline_name,
 	.release = drm_sched_fence_release_finished,
+	.set_deadline = drm_sched_fence_set_deadline_finished,
 };
 
 struct drm_sched_fence *to_drm_sched_fence(struct dma_fence *f)
diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
index a2a953693b45..3ab0900d3596 100644
--- a/drivers/gpu/drm/scheduler/sched_main.c
+++ b/drivers/gpu/drm/scheduler/sched_main.c
@@ -818,6 +818,9 @@ static int drm_sched_main(void *param)
 
 		if (!IS_ERR_OR_NULL(fence)) {
 			s_fence->parent = dma_fence_get(fence);
+			if (test_bit(DMA_FENCE_FLAG_HAS_DEADLINE_BIT,
+				     &s_fence->finished.flags))
+				dma_fence_set_deadline(fence, s_fence->deadline);
 			r = dma_fence_add_callback(fence, &sched_job->cb,
 						   drm_sched_job_done_cb);
 			if (r == -ENOENT)
diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h
index d18af49fd009..0f08ade614ae 100644
--- a/include/drm/gpu_scheduler.h
+++ b/include/drm/gpu_scheduler.h
@@ -144,6 +144,12 @@ struct drm_sched_fence {
          */
 	struct dma_fence		finished;
 
+	/**
+	 * @deadline: deadline set on &drm_sched_fence.finished which
+	 * potentially needs to be propagated to &drm_sched_fence.parent
+	 */
+	ktime_t				deadline;
+
         /**
          * @parent: the fence returned by &drm_sched_backend_ops.run_job
          * when scheduling the job on hardware. We signal the
-- 
2.31.1