Re: [PATCH v5 11/16] rpmsg: virtio: register the rpmsg_ctrl device

[Arnaud POULIQUEN <arnaud.pouliquen@foss.st.com>]

On 3/3/21 7:43 PM, Mathieu Poirier wrote:
> On Fri, Feb 19, 2021 at 12:14:56PM +0100, Arnaud Pouliquen wrote:
>> Instantiate the rpmsg_ioctl device on virtio RPMsg bus creation.
> 
> s/rpmsg_ioctl/rpmsg_ctrl
> 
> Now I understand what you meant in patch 05.
> 
>> This provides the possibility to expose the RPMSG_CREATE_EPT_IOCTL
>> to create RPMsg chdev endpoints.
> 
> You mean RPMSG device endpoints, i.e rpmsg_eptdev?  If so I think it should be
> added to the changelog.  Otherwiser someone could be tempted to look for "chdev"
> and find anything but a rpmsg_eptdev.

In fact it is RPMsg char device endpoints, I will add more explicit details in
the changelog.

> 
>>
>> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
>>
>> ---
>> V5:
>> Fix compilation issue
>> Reported-by: kernel test robot <lkp@intel.com>
>> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
>> ---
>>  drivers/rpmsg/virtio_rpmsg_bus.c | 57 +++++++++++++++++++++++++++++---
>>  1 file changed, 52 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c b/drivers/rpmsg/virtio_rpmsg_bus.c
>> index e87d4cf926eb..2e6b34084012 100644
>> --- a/drivers/rpmsg/virtio_rpmsg_bus.c
>> +++ b/drivers/rpmsg/virtio_rpmsg_bus.c
>> @@ -813,14 +813,52 @@ static void rpmsg_xmit_done(struct virtqueue *svq)
>>  	wake_up_interruptible(&vrp->sendq);
>>  }
>>  
>> +static struct rpmsg_device *rpmsg_virtio_add_ctrl_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) {
>> +		kfree(vch);
>> +		return ERR_PTR(err);
>> +	}
>> +
>> +	return rpdev_ctrl;
>> +}
>> +
>> +static void rpmsg_virtio_del_ctrl_dev(struct rpmsg_device *rpdev_ctrl)
>> +{
>> +	if (!rpdev_ctrl)
>> +		return;
>> +	kfree(to_virtio_rpmsg_channel(rpdev_ctrl));
>> +}
>> +
>>  static int rpmsg_probe(struct virtio_device *vdev)
>>  {
>>  	vq_callback_t *vq_cbs[] = { rpmsg_recv_done, rpmsg_xmit_done };
>>  	static const char * const names[] = { "input", "output" };
>>  	struct virtqueue *vqs[2];
>>  	struct virtproc_info *vrp;
>> -	struct virtio_rpmsg_channel *vch;
>> -	struct rpmsg_device *rpdev_ns;
>> +	struct virtio_rpmsg_channel *vch = NULL;
>> +	struct rpmsg_device *rpdev_ns = NULL, *rpdev_ctrl;
> 
> As far as I can tell @rpdev_ns doesn't have to be initialized.

You are right,no more needed in V5 with the error cases restructuring.

Thanks,
Arnaud

> 
>>  	void *bufs_va;
>>  	int err = 0, i;
>>  	size_t total_buf_space;
>> @@ -894,12 +932,18 @@ static int rpmsg_probe(struct virtio_device *vdev)
>>  
>>  	vdev->priv = vrp;
>>  
>> +	rpdev_ctrl = rpmsg_virtio_add_ctrl_dev(vdev);
>> +	if (IS_ERR(rpdev_ctrl)) {
>> +		err = PTR_ERR(rpdev_ctrl);
>> +		goto free_coherent;
>> +	}
>> +
>>  	/* if supported by the remote processor, enable the name service */
>>  	if (virtio_has_feature(vdev, VIRTIO_RPMSG_F_NS)) {
>>  		vch = kzalloc(sizeof(*vch), GFP_KERNEL);
>>  		if (!vch) {
>>  			err = -ENOMEM;
>> -			goto free_coherent;
>> +			goto free_ctrldev;
>>  		}
>>  
>>  		/* Link the channel to our vrp */
>> @@ -915,7 +959,7 @@ static int rpmsg_probe(struct virtio_device *vdev)
>>  
>>  		err = rpmsg_ns_register_device(rpdev_ns);
>>  		if (err)
>> -			goto free_coherent;
>> +			goto free_vch;
>>  	}
>>  
>>  	/*
>> @@ -939,8 +983,11 @@ static int rpmsg_probe(struct virtio_device *vdev)
>>  
>>  	return 0;
>>  
>> -free_coherent:
>> +free_vch:
>>  	kfree(vch);
>> +free_ctrldev:
>> +	rpmsg_virtio_del_ctrl_dev(rpdev_ctrl);
>> +free_coherent:
>>  	dma_free_coherent(vdev->dev.parent, total_buf_space,
>>  			  bufs_va, vrp->bufs_dma);
>>  vqs_del:
>> -- 
>> 2.17.1
>>