drm/vc4: improve throughput by pipelining binning and rendering jobs

The hardware provides us with separate threads for binning and
rendering, and the existing model waits for them both to complete
before submitting the next job.

Splitting the binning and rendering submissions reduces idle time and
gives us approx 20-30% speedup with some x11perf tests such as -line10
and -tilerect1.  Improves openarena performance by 1.01897% +/-
0.247857% (n=16).

Thanks to anholt for suggesting this.

v2: Rebase on the spurious resets fix (change by anholt).

Signed-off-by: Varad Gautam <varadgautam@gmail.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Eric Anholt <eric@anholt.net>

1 files changed, 49 insertions, 9 deletions

diff --git a/drivers/gpu/drm/vc4/vc4_irq.c b/drivers/gpu/drm/vc4/vc4_irq.c
index 78a21357fb2d..b0104a346a74 100644
--- a/drivers/gpu/drm/vc4/vc4_irq.c
+++ b/drivers/gpu/drm/vc4/vc4_irq.c
@@ -30,6 +30,10 @@
  * disables that specific interrupt, and 0s written are ignored
  * (reading either one returns the set of enabled interrupts).
  *
+ * When we take a binning flush done interrupt, we need to submit the
+ * next frame for binning and move the finished frame to the render
+ * thread.
+ *
  * When we take a render frame interrupt, we need to wake the
  * processes waiting for some frame to be done, and get the next frame
  * submitted ASAP (so the hardware doesn't sit idle when there's work
@@ -44,6 +48,7 @@
 #include "vc4_regs.h"
 
 #define V3D_DRIVER_IRQS (V3D_INT_OUTOMEM | \
+			 V3D_INT_FLDONE | \
 			 V3D_INT_FRDONE)
 
 DECLARE_WAIT_QUEUE_HEAD(render_wait);
@@ -77,7 +82,7 @@ vc4_overflow_mem_work(struct work_struct *work)
 		unsigned long irqflags;
 
 		spin_lock_irqsave(&vc4->job_lock, irqflags);
-		current_exec = vc4_first_job(vc4);
+		current_exec = vc4_first_bin_job(vc4);
 		if (current_exec) {
 			vc4->overflow_mem->seqno = vc4->finished_seqno + 1;
 			list_add_tail(&vc4->overflow_mem->unref_head,
@@ -98,17 +103,43 @@ vc4_overflow_mem_work(struct work_struct *work)
 }
 
 static void
-vc4_irq_finish_job(struct drm_device *dev)
+vc4_irq_finish_bin_job(struct drm_device *dev)
+{
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
+	struct vc4_exec_info *exec = vc4_first_bin_job(vc4);
+
+	if (!exec)
+		return;
+
+	vc4_move_job_to_render(dev, exec);
+	vc4_submit_next_bin_job(dev);
+}
+
+static void
+vc4_cancel_bin_job(struct drm_device *dev)
+{
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
+	struct vc4_exec_info *exec = vc4_first_bin_job(vc4);
+
+	if (!exec)
+		return;
+
+	list_move_tail(&exec->head, &vc4->bin_job_list);
+	vc4_submit_next_bin_job(dev);
+}
+
+static void
+vc4_irq_finish_render_job(struct drm_device *dev)
 {
 	struct vc4_dev *vc4 = to_vc4_dev(dev);
-	struct vc4_exec_info *exec = vc4_first_job(vc4);
+	struct vc4_exec_info *exec = vc4_first_render_job(vc4);
 
 	if (!exec)
 		return;
 
 	vc4->finished_seqno++;
 	list_move_tail(&exec->head, &vc4->job_done_list);
-	vc4_submit_next_job(dev);
+	vc4_submit_next_render_job(dev);
 
 	wake_up_all(&vc4->job_wait_queue);
 	schedule_work(&vc4->job_done_work);
@@ -125,9 +156,10 @@ vc4_irq(int irq, void *arg)
 	barrier();
 	intctl = V3D_READ(V3D_INTCTL);
 
-	/* Acknowledge the interrupts we're handling here. The render
-	 * frame done interrupt will be cleared, while OUTOMEM will
-	 * stay high until the underlying cause is cleared.
+	/* Acknowledge the interrupts we're handling here. The binner
+	 * last flush / render frame done interrupt will be cleared,
+	 * while OUTOMEM will stay high until the underlying cause is
+	 * cleared.
 	 */
 	V3D_WRITE(V3D_INTCTL, intctl);
 
@@ -138,9 +170,16 @@ vc4_irq(int irq, void *arg)
 		status = IRQ_HANDLED;
 	}
 
+	if (intctl & V3D_INT_FLDONE) {
+		spin_lock(&vc4->job_lock);
+		vc4_irq_finish_bin_job(dev);
+		spin_unlock(&vc4->job_lock);
+		status = IRQ_HANDLED;
+	}
+
 	if (intctl & V3D_INT_FRDONE) {
 		spin_lock(&vc4->job_lock);
-		vc4_irq_finish_job(dev);
+		vc4_irq_finish_render_job(dev);
 		spin_unlock(&vc4->job_lock);
 		status = IRQ_HANDLED;
 	}
@@ -205,6 +244,7 @@ void vc4_irq_reset(struct drm_device *dev)
 	V3D_WRITE(V3D_INTENA, V3D_DRIVER_IRQS);
 
 	spin_lock_irqsave(&vc4->job_lock, irqflags);
-	vc4_irq_finish_job(dev);
+	vc4_cancel_bin_job(dev);
+	vc4_irq_finish_render_job(dev);
 	spin_unlock_irqrestore(&vc4->job_lock, irqflags);
 }