drm/etnaviv: refcount the submit object

The submit object lifetime will get extended to the actual GPU
execution. As multiple users will depend on this, add a kref to
properly control destruction of the object.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>

drivers/gpu/drm/etnaviv/etnaviv_gem.h

@@ -101,6 +101,7 @@ struct etnaviv_gem_submit_bo {
  * lasts for the duration of the submit-ioctl.
  */
 struct etnaviv_gem_submit {
+	struct kref refcount;
 	struct etnaviv_gpu *gpu;
 	struct dma_fence *out_fence, *in_fence;
 	u32 flags;
@@ -109,6 +110,8 @@ struct etnaviv_gem_submit {
 	/* No new members here, the previous one is variable-length! */
 };
 
+void etnaviv_submit_put(struct etnaviv_gem_submit * submit);
+
 int etnaviv_gem_wait_bo(struct etnaviv_gpu *gpu, struct drm_gem_object *obj,
 	struct timespec *timeout);
 int etnaviv_gem_new_private(struct drm_device *dev, size_t size, u32 flags,

drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c

@@ -43,6 +43,7 @@ static struct etnaviv_gem_submit *submit_create(struct drm_device *dev,
 		return NULL;
 
 	submit->gpu = gpu;
+	kref_init(&submit->refcount);
 
 	return submit;
 }
@@ -341,8 +342,10 @@ static int submit_perfmon_validate(struct etnaviv_gem_submit *submit,
 	return 0;
 }
 
-static void submit_cleanup(struct etnaviv_gem_submit *submit)
+static void submit_cleanup(struct kref *kref)
 {
+	struct etnaviv_gem_submit *submit =
+			container_of(kref, struct etnaviv_gem_submit, refcount);
 	unsigned i;
 
 	for (i = 0; i < submit->nr_bos; i++) {
@@ -367,6 +370,11 @@ static void submit_cleanup(struct etnaviv_gem_submit *submit)
 	kfree(submit);
 }
 
+void etnaviv_submit_put(struct etnaviv_gem_submit *submit)
+{
+	kref_put(&submit->refcount, submit_cleanup);
+}
+
 int etnaviv_ioctl_gem_submit(struct drm_device *dev, void *data,
 		struct drm_file *file)
 {
@@ -544,7 +552,7 @@ int etnaviv_ioctl_gem_submit(struct drm_device *dev, void *data,
 	args->fence = submit->out_fence->seqno;
 
 err_submit_objects:
-	submit_cleanup(submit);
+	etnaviv_submit_put(submit);
 
 err_submit_ww_acquire:
 	ww_acquire_fini(&ticket);