[PATCH v4 11/16] rpmsg: virtio: register the rpmsg_ctrl device

[Arnaud Pouliquen]

Instantiate the rpmsg_ioctl device on virtio RPMsg bus creation.
This provides the possibility to expose the RPMSG_CREATE_EPT_IOCTL
to create RPMsg chdev endpoints.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxxxxxxx>

---
V3:
Fix compilation issue
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

warnings:
drivers/rpmsg/virtio_rpmsg_bus.c:978 rpmsg_probe() error: uninitialized symbol 'vch'.
drivers/rpmsg/virtio_rpmsg_bus.c:979 rpmsg_probe() error: uninitialized symbol 'rpdev_ctrl'.
---
 drivers/rpmsg/virtio_rpmsg_bus.c | 37 +++++++++++++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c b/drivers/rpmsg/virtio_rpmsg_bus.c
index e87d4cf926eb..5143fdeca306 100644
--- a/drivers/rpmsg/virtio_rpmsg_bus.c
+++ b/drivers/rpmsg/virtio_rpmsg_bus.c
@@ -813,6 +813,35 @@ static void rpmsg_xmit_done(struct virtqueue *svq)
 	wake_up_interruptible(&vrp->sendq);
 }
 
+static struct rpmsg_device *rpmsg_virtio_add_char_dev(struct virtio_device *vdev)
+{
+	struct virtproc_info *vrp = vdev->priv;
+	struct virtio_rpmsg_channel *vch;
+	struct rpmsg_device *rpdev_ctrl;
+	int err = 0;
+
+	vch = kzalloc(sizeof(*vch), GFP_KERNEL);
+	if (!vch)
+		return ERR_PTR(-ENOMEM);
+
+	/* Link the channel to the vrp */
+	vch->vrp = vrp;
+
+	/* Assign public information to the rpmsg_device */
+	rpdev_ctrl = &vch->rpdev;
+	rpdev_ctrl->ops = &virtio_rpmsg_ops;
+
+	rpdev_ctrl->dev.parent = &vrp->vdev->dev;
+	rpdev_ctrl->dev.release = virtio_rpmsg_release_device;
+	rpdev_ctrl->little_endian = virtio_is_little_endian(vrp->vdev);
+
+	err = rpmsg_ctrl_register_device(rpdev_ctrl);
+	if (err)
+		return ERR_PTR(err);
+
+	return rpdev_ctrl;
+}
+
 static int rpmsg_probe(struct virtio_device *vdev)
 {
 	vq_callback_t *vq_cbs[] = { rpmsg_recv_done, rpmsg_xmit_done };
@@ -820,7 +849,7 @@ static int rpmsg_probe(struct virtio_device *vdev)
 	struct virtqueue *vqs[2];
 	struct virtproc_info *vrp;
 	struct virtio_rpmsg_channel *vch;
-	struct rpmsg_device *rpdev_ns;
+	struct rpmsg_device *rpdev_ns = NULL, *rpdev_ctrl = NULL;
 	void *bufs_va;
 	int err = 0, i;
 	size_t total_buf_space;
@@ -918,6 +947,11 @@ static int rpmsg_probe(struct virtio_device *vdev)
 			goto free_coherent;
 	}
 
+	rpdev_ctrl = rpmsg_virtio_add_char_dev(vdev);
+	if (IS_ERR(rpdev_ctrl)) {
+		err = PTR_ERR(rpdev_ctrl);
+		goto free_coherent;
+	}
 	/*
 	 * Prepare to kick but don't notify yet - we can't do this before
 	 * device is ready.
@@ -941,6 +975,7 @@ static int rpmsg_probe(struct virtio_device *vdev)
 
 free_coherent:
 	kfree(vch);
+	kfree(to_virtio_rpmsg_channel(rpdev_ctrl));
 	dma_free_coherent(vdev->dev.parent, total_buf_space,
 			  bufs_va, vrp->bufs_dma);
 vqs_del:
-- 
2.17.1