virtio-gpu: add virtio_gpu_queue_ctrl_buffer_locked

Add virtio_gpu_queue_ctrl_buffer_locked function, which does the same as
virtio_gpu_queue_ctrl_buffer but does not take the virtqueue lock.  The
caller must hold the lock instead.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c
index 1698669f4185747ce3ce51f1d933c8668ee5c726..5b9bc242890fea4720278f7acd1e549a18aaf961 100644 (file)
--- a/drivers/gpu/drm/virtio/virtgpu_vq.c
+++ b/drivers/gpu/drm/virtio/virtgpu_vq.c
@@ -293,8 +293,8 @@ void virtio_gpu_dequeue_cursor_func(struct work_struct *work)
        wake_up(&vgdev->cursorq.ack_queue);
 }
 
-static int virtio_gpu_queue_ctrl_buffer(struct virtio_gpu_device *vgdev,
-                                       struct virtio_gpu_vbuffer *vbuf)
+static int virtio_gpu_queue_ctrl_buffer_locked(struct virtio_gpu_device *vgdev,
+                                              struct virtio_gpu_vbuffer *vbuf)
 {
        struct virtqueue *vq = vgdev->ctrlq.vq;
        struct scatterlist *sgs[3], vcmd, vout, vresp;
@@ -320,7 +320,6 @@ static int virtio_gpu_queue_ctrl_buffer(struct virtio_gpu_device *vgdev,
                incnt++;
        }
 
-       spin_lock(&vgdev->ctrlq.qlock);
 retry:
        ret = virtqueue_add_sgs(vq, sgs, outcnt, incnt, vbuf, GFP_ATOMIC);
        if (ret == -ENOSPC) {
@@ -331,13 +330,23 @@ retry:
        } else {
                virtqueue_kick(vq);
        }
-       spin_unlock(&vgdev->ctrlq.qlock);
 
        if (!ret)
                ret = vq->num_free;
        return ret;
 }
 
+static int virtio_gpu_queue_ctrl_buffer(struct virtio_gpu_device *vgdev,
+                                       struct virtio_gpu_vbuffer *vbuf)
+{
+       int rc;
+
+       spin_lock(&vgdev->ctrlq.qlock);
+       rc = virtio_gpu_queue_ctrl_buffer_locked(vgdev, vbuf);
+       spin_unlock(&vgdev->ctrlq.qlock);
+       return rc;
+}
+
 static int virtio_gpu_queue_cursor(struct virtio_gpu_device *vgdev,
                                   struct virtio_gpu_vbuffer *vbuf)
 {