Linux Virtualization - Jul 2019 - [PATCH v6 02/18] drm/virtio: switch virtio_gpu_wait_ioctl() to gem helper.

Use drm_gem_reservation_object_wait() in virtio_gpu_wait_ioctl().
This also makes the ioctl run lockless.

v5: handle lookup failure.
v2: use reservation_object_test_signaled_rcu for VIRTGPU_WAIT_NOWAIT.

Signed-off-by: Gerd Hoffmann <kraxel at redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/virtio/virtgpu_ioctl.c | 28 ++++++++++++--------------
 1 file changed, 13 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c
b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
index 1b50c34a29dc..c06dde541491 100644
--- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c
+++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
@@ -464,23 +464,21 @@ static int virtio_gpu_wait_ioctl(struct drm_device *dev,
void *data,
 			    struct drm_file *file)
 {
 	struct drm_virtgpu_3d_wait *args = data;
-	struct drm_gem_object *gobj = NULL;
-	struct virtio_gpu_object *qobj = NULL;
+	struct drm_gem_object *obj;
+	long timeout = 15 * HZ;
 	int ret;
-	bool nowait = false;
 
-	gobj = drm_gem_object_lookup(file, args->handle);
-	if (gobj == NULL)
-		return -ENOENT;
-
-	qobj = gem_to_virtio_gpu_obj(gobj);
-
-	if (args->flags & VIRTGPU_WAIT_NOWAIT)
-		nowait = true;
-	ret = virtio_gpu_object_wait(qobj, nowait);
-
-	drm_gem_object_put_unlocked(gobj);
-	return ret;
+	if (args->flags & VIRTGPU_WAIT_NOWAIT) {
+		obj = drm_gem_object_lookup(file, args->handle);
+		if (obj == NULL)
+			return -ENOENT;
+		ret = reservation_object_test_signaled_rcu(obj->resv, true);
+		drm_gem_object_put_unlocked(obj);
+		return ret ? 0 : -EBUSY;
+	}
+
+	return drm_gem_reservation_object_wait(file, args->handle,
+					       true, timeout);
 }
 
 static int virtio_gpu_get_caps_ioctl(struct drm_device *dev,
-- 
2.18.1