linux-kernel - Re: [PATCH V5 1/3] rpmsg: core: Add signal API support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <0543735a-5f0c-bdf4-2a89-e94841bd4a68@foss.st.com>
Date:   Wed, 19 Apr 2023 11:53:49 +0200
From:   Arnaud POULIQUEN <arnaud.pouliquen@...s.st.com>
To:     Sarannya S <quic_sarannya@...cinc.com>,
        <quic_bjorande@...cinc.com>, <swboyd@...omium.org>,
        <quic_clew@...cinc.com>, <mathieu.poirier@...aro.org>
CC:     <linux-kernel@...r.kernel.org>, <linux-arm-msm@...r.kernel.org>,
        <linux-remoteproc@...r.kernel.org>,
        Deepak Kumar Singh <quic_deesin@...cinc.com>,
        Bjorn Andersson <andersson@...nel.org>
Subject: Re: [PATCH V5 1/3] rpmsg: core: Add signal API support

Hi,


On 4/18/23 10:48, Sarannya S wrote:
> From: Deepak Kumar Singh <quic_deesin@...cinc.com>
> 
> Some transports like Glink support the state notifications between
> clients using flow control signals similar to serial protocol signals.
> Local glink client drivers can send and receive flow control status
> to glink clients running on remote processors.
> 
> Add APIs to support sending and receiving of flow control status by
> rpmsg clients.
> 
> Signed-off-by: Deepak Kumar Singh <quic_deesin@...cinc.com>
> Signed-off-by: Sarannya S <quic_sarannya@...cinc.com>
> ---
>  drivers/rpmsg/rpmsg_core.c     | 20 ++++++++++++++++++++
>  drivers/rpmsg/rpmsg_internal.h |  2 ++
>  2 files changed, 22 insertions(+)
> 
> diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c
> index a2207c0..86b4912 100644
> --- a/drivers/rpmsg/rpmsg_core.c
> +++ b/drivers/rpmsg/rpmsg_core.c
> @@ -331,6 +331,24 @@ int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
>  EXPORT_SYMBOL(rpmsg_trysend_offchannel);
>  
>  /**
> + * rpmsg_set_flow_control() - sets/clears serial flow control signals
> + * @ept:	the rpmsg endpoint
> + * @enable:	pause/resume incoming data flow
> + *
> + * Return: 0 on success and an appropriate error value on failure.
> + */
> +int rpmsg_set_flow_control(struct rpmsg_endpoint *ept, bool enable)


Regression since V4[1]

In V4 version the function was:

int rpmsg_set_flow_control(struct rpmsg_endpoint *ept, bool enable, u32 dst)

Following comments on V3 [2]

Without dst parameter it is not compatible with the rpmsg_virtio backend


[1]https://lkml.org/lkml/2022/12/7/506
[2]https://www.spinics.net/lists/kernel/msg4573082.html

Regards
Arnaud

> +{
> +	if (WARN_ON(!ept))
> +		return -EINVAL;
> +	if (!ept->ops->set_flow_control)
> +		return -ENXIO;
> +
> +	return ept->ops->set_flow_control(ept, enable);
> +}
> +EXPORT_SYMBOL(rpmsg_set_flow_control);
> +
> +/**
>   * rpmsg_get_mtu() - get maximum transmission buffer size for sending message.
>   * @ept: the rpmsg endpoint
>   *
> @@ -539,6 +557,8 @@ static int rpmsg_dev_probe(struct device *dev)
>  
>  		rpdev->ept = ept;
>  		rpdev->src = ept->addr;
> +
> +		ept->flow_cb = rpdrv->flowcontrol;
>  	}
>  
>  	err = rpdrv->probe(rpdev);
> diff --git a/drivers/rpmsg/rpmsg_internal.h b/drivers/rpmsg/rpmsg_internal.h
> index 39b646d..4fea45a 100644
> --- a/drivers/rpmsg/rpmsg_internal.h
> +++ b/drivers/rpmsg/rpmsg_internal.h
> @@ -55,6 +55,7 @@ struct rpmsg_device_ops {
>   * @trysendto:		see @rpmsg_trysendto(), optional
>   * @trysend_offchannel:	see @rpmsg_trysend_offchannel(), optional
>   * @poll:		see @rpmsg_poll(), optional
> + * @set_flow_control:	see @rpmsg_set_flow_control(), optional
>   * @get_mtu:		see @rpmsg_get_mtu(), optional
>   *
>   * Indirection table for the operations that a rpmsg backend should implement.
> @@ -75,6 +76,7 @@ struct rpmsg_endpoint_ops {
>  			     void *data, int len);
>  	__poll_t (*poll)(struct rpmsg_endpoint *ept, struct file *filp,
>  			     poll_table *wait);
> +	int (*set_flow_control)(struct rpmsg_endpoint *ept, bool enable);
>  	ssize_t (*get_mtu)(struct rpmsg_endpoint *ept);
>  };
>