Linux Virtualization - Dec 2019 - [PATCH AUTOSEL 5.4 002/350] drm/virtio: switch virtio_gpu_wait_ioctl() to gem helper.

From: Gerd Hoffmann <kraxel at redhat.com>

[ Upstream commit 29cf12394c0565d7eb1685bf0c1b4749aa6a8b66 ]

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

v9: fix return value.
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>
Reviewed-by: Chia-I Wu <olvaffe at gmail.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20190829103301.3539-3-kraxel
at redhat.com
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
 drivers/gpu/drm/virtio/virtgpu_ioctl.c | 28 +++++++++++++++-----------
 1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c
b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
index 0a88ef11b9d3f..a662394f68921 100644
--- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c
+++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
@@ -463,25 +463,29 @@ out:
 }
 
 static int virtio_gpu_wait_ioctl(struct drm_device *dev, void *data,
-			    struct drm_file *file)
+				 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)
+	obj = drm_gem_object_lookup(file, args->handle);
+	if (obj == 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);
+	if (args->flags & VIRTGPU_WAIT_NOWAIT) {
+		ret = dma_resv_test_signaled_rcu(obj->resv, true);
+	} else {
+		ret = dma_resv_wait_timeout_rcu(obj->resv, true, true,
+						timeout);
+	}
+	if (ret == 0)
+		ret = -EBUSY;
+	else if (ret > 0)
+		ret = 0;
 
-	drm_gem_object_put_unlocked(gobj);
+	drm_gem_object_put_unlocked(obj);
 	return ret;
 }
 
-- 
2.20.1