drm/vc4: Allocate binner bo when starting to use the V3D

The binner BO is not required until the V3D is in use, so avoid
allocating it at probe and do it on the first non-dumb BO allocation.

Keep track of which clients are using the V3D and liberate the buffer
when there is none left, using a kref. Protect the logic with a
mutex to avoid race conditions.

The binner BO is created at the time of the first render ioctl and is
destroyed when there is no client and no exec job using it left.

The Out-Of-Memory (OOM) interrupt also gets some tweaking, to avoid
enabling it before having allocated a binner bo.

We also want to keep the BO alive during runtime suspend/resume to avoid
failing to allocate it at resume. This happens when the CMA pool is
full at that point and results in a hard crash.

Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20190516145544.29051-5-paul.kocialkowski@bootlin.com

1 files changed, 15 insertions, 6 deletions

diff --git a/drivers/gpu/drm/vc4/vc4_irq.c b/drivers/gpu/drm/vc4/vc4_irq.c
index 723dc86b4511..e226c24e543f 100644
--- a/drivers/gpu/drm/vc4/vc4_irq.c
+++ b/drivers/gpu/drm/vc4/vc4_irq.c
@@ -59,18 +59,22 @@ vc4_overflow_mem_work(struct work_struct *work)
 {
 	struct vc4_dev *vc4 =
 		container_of(work, struct vc4_dev, overflow_mem_work);
-	struct vc4_bo *bo = vc4->bin_bo;
+	struct vc4_bo *bo;
 	int bin_bo_slot;
 	struct vc4_exec_info *exec;
 	unsigned long irqflags;
 
-	if (!bo)
-		return;
+	mutex_lock(&vc4->bin_bo_lock);
+
+	if (!vc4->bin_bo)
+		goto complete;
+
+	bo = vc4->bin_bo;
 
 	bin_bo_slot = vc4_v3d_get_bin_slot(vc4);
 	if (bin_bo_slot < 0) {
 		DRM_ERROR("Couldn't allocate binner overflow mem\n");
-		return;
+		goto complete;
 	}
 
 	spin_lock_irqsave(&vc4->job_lock, irqflags);
@@ -101,6 +105,9 @@ vc4_overflow_mem_work(struct work_struct *work)
 	V3D_WRITE(V3D_INTCTL, V3D_INT_OUTOMEM);
 	V3D_WRITE(V3D_INTENA, V3D_INT_OUTOMEM);
 	spin_unlock_irqrestore(&vc4->job_lock, irqflags);
+
+complete:
+	mutex_unlock(&vc4->bin_bo_lock);
 }
 
 static void
@@ -252,8 +259,10 @@ vc4_irq_postinstall(struct drm_device *dev)
 	if (!vc4->v3d)
 		return 0;
 
-	/* Enable both the render done and out of memory interrupts. */
-	V3D_WRITE(V3D_INTENA, V3D_DRIVER_IRQS);
+	/* Enable the render done interrupts. The out-of-memory interrupt is
+	 * enabled as soon as we have a binner BO allocated.
+	 */
+	V3D_WRITE(V3D_INTENA, V3D_INT_FLDONE | V3D_INT_FRDONE);
 
 	return 0;
 }