[PATCH v3 1/7] virtio-gpu: add virtio_gpu_queue_ctrl_buffer_locked

Gerd Hoffmann
2015-10-02T11:58:39Z

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>
---
drivers/gpu/drm/virtio/virtgpu_vq.c | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c
index 1698669f..5b9bc24 100644
--- 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)
{
--
1.8.3.1