From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5B5B7C77B61 for ; Mon, 24 Apr 2023 13:34:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232535AbjDXNeJ (ORCPT ); Mon, 24 Apr 2023 09:34:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34414 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232480AbjDXNdp (ORCPT ); Mon, 24 Apr 2023 09:33:45 -0400 Received: from mx07-00178001.pphosted.com (mx07-00178001.pphosted.com [185.132.182.106]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E72767AA4; Mon, 24 Apr 2023 06:33:32 -0700 (PDT) Received: from pps.filterd (m0241204.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 33OAJVb4015326; 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Mon, 24 Apr 2023 15:33:19 +0200 (CEST) Received: from Webmail-eu.st.com (shfdag1node2.st.com [10.75.129.70]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 5019022FA5E; Mon, 24 Apr 2023 15:33:19 +0200 (CEST) Received: from [10.252.21.25] (10.252.21.25) by SHFDAG1NODE2.st.com (10.75.129.70) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.21; Mon, 24 Apr 2023 15:33:18 +0200 Message-ID: <2fe5b739-b700-0fa7-78df-fde9358c794e@foss.st.com> Date: Mon, 24 Apr 2023 15:33:18 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.10.0 Subject: Re: [PATCH V7 3/3] rpmsg: char: Add RPMSG GET/SET FLOWCONTROL IOCTL support Content-Language: en-US To: Sarannya S , , , , CC: , , , Deepak Kumar Singh , Bjorn Andersson References: <1682160127-18103-1-git-send-email-quic_sarannya@quicinc.com> <1682160127-18103-4-git-send-email-quic_sarannya@quicinc.com> From: Arnaud POULIQUEN Organization: STMicroelectronics In-Reply-To: <1682160127-18103-4-git-send-email-quic_sarannya@quicinc.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.252.21.25] X-ClientProxiedBy: SHFCAS1NODE1.st.com (10.75.129.72) To SHFDAG1NODE2.st.com (10.75.129.70) X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-04-24_07,2023-04-21_01,2023-02-09_01 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/22/23 12:42, Sarannya S wrote: > From: Chris Lew > > Add RPMSG_GET_OUTGOING_FLOWCONTROL and RPMSG_SET_INCOMING_FLOWCONTROL > IOCTL support for rpmsg char device nodes to get/set the low level > transport signals. > > Signed-off-by: Chris Lew > Signed-off-by: Deepak Kumar Singh > Signed-off-by: Sarannya S > --- > drivers/rpmsg/rpmsg_char.c | 49 ++++++++++++++++++++++++++++++++++++++++------ > include/uapi/linux/rpmsg.h | 11 ++++++++++- > 2 files changed, 53 insertions(+), 7 deletions(-) > > diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c > index a271fce..d50908f 100644 > --- a/drivers/rpmsg/rpmsg_char.c > +++ b/drivers/rpmsg/rpmsg_char.c > @@ -23,6 +23,7 @@ > #include > #include > #include > +#include Seems useless now > #include > #include > > @@ -68,6 +69,8 @@ struct rpmsg_eptdev { > struct sk_buff_head queue; > wait_queue_head_t readq; > > + bool remote_flow; > + bool remote_flow_updated; > }; > > int rpmsg_chrdev_eptdev_destroy(struct device *dev, void *data) > @@ -116,6 +119,18 @@ static int rpmsg_ept_cb(struct rpmsg_device *rpdev, void *buf, int len, > return 0; > } > > +static int rpmsg_ept_flow_cb(struct rpmsg_device *rpdev, void *priv, bool enable) > +{ > + struct rpmsg_eptdev *eptdev = priv; > + > + eptdev->remote_flow = enable; > + eptdev->remote_flow_updated = true; > + > + wake_up_interruptible(&eptdev->readq); > + > + return 0; > +} > + > static int rpmsg_eptdev_open(struct inode *inode, struct file *filp) > { > struct rpmsg_eptdev *eptdev = cdev_to_eptdev(inode->i_cdev); > @@ -152,6 +167,7 @@ static int rpmsg_eptdev_open(struct inode *inode, struct file *filp) > return -EINVAL; > } > > + ept->flow_cb = rpmsg_ept_flow_cb; > eptdev->ept = ept; > filp->private_data = eptdev; > mutex_unlock(&eptdev->ept_lock); > @@ -172,6 +188,7 @@ static int rpmsg_eptdev_release(struct inode *inode, struct file *filp) > eptdev->ept = NULL; > } > mutex_unlock(&eptdev->ept_lock); > + eptdev->remote_flow_updated = false; > > /* Discard all SKBs */ > skb_queue_purge(&eptdev->queue); > @@ -285,6 +302,9 @@ static __poll_t rpmsg_eptdev_poll(struct file *filp, poll_table *wait) > if (!skb_queue_empty(&eptdev->queue)) > mask |= EPOLLIN | EPOLLRDNORM; > > + if (eptdev->remote_flow_updated) > + mask |= EPOLLPRI; > + > mutex_lock(&eptdev->ept_lock); > mask |= rpmsg_poll(eptdev->ept, filp, wait); > mutex_unlock(&eptdev->ept_lock); > @@ -297,14 +317,31 @@ static long rpmsg_eptdev_ioctl(struct file *fp, unsigned int cmd, > { > struct rpmsg_eptdev *eptdev = fp->private_data; > > - if (cmd != RPMSG_DESTROY_EPT_IOCTL) > - return -EINVAL; > + bool set; > + int ret; > > - /* Don't allow to destroy a default endpoint. */ > - if (eptdev->default_ept) > - return -EINVAL; > + switch (cmd) { > + case RPMSG_GET_OUTGOING_FLOWCONTROL: > + eptdev->remote_flow_updated = false; > + ret = put_user(eptdev->remote_flow, (int __user *)arg); If the rpmsg_set_flow_control is not implemented on remote side or in the backend then we should return true by default. Else the communication should not be possible if eptdev->remote_flow is not initialized. Perhaps adding a "flow_ctrl" boolean in the rpmsg_device (similar to the "announce") would give the information if the flow control is supported or not. This "flow_ctrl" boolean would be initialized by the backend. Regards Arnaud > + break; > + case RPMSG_SET_INCOMING_FLOWCONTROL: > + set = !!arg; > + ret = rpmsg_set_flow_control(eptdev->ept, set, eptdev->chinfo.dst); > + break; > + case RPMSG_DESTROY_EPT_IOCTL: > + /* Don't allow to destroy a default endpoint. */ > + if (eptdev->default_ept) { > + ret = -EINVAL; > + break; > + } > + ret = rpmsg_chrdev_eptdev_destroy(&eptdev->dev, NULL); > + break; > + default: > + ret = -EINVAL; > + } > > - return rpmsg_chrdev_eptdev_destroy(&eptdev->dev, NULL); > + return ret; > } > > static const struct file_operations rpmsg_eptdev_fops = { > diff --git a/include/uapi/linux/rpmsg.h b/include/uapi/linux/rpmsg.h > index 1637e68..c955e27 100644 > --- a/include/uapi/linux/rpmsg.h > +++ b/include/uapi/linux/rpmsg.h > @@ -10,7 +10,6 @@ > #include > > #define RPMSG_ADDR_ANY 0xFFFFFFFF > - > /** > * struct rpmsg_endpoint_info - endpoint info representation > * @name: name of service > @@ -43,4 +42,14 @@ struct rpmsg_endpoint_info { > */ > #define RPMSG_RELEASE_DEV_IOCTL _IOW(0xb5, 0x4, struct rpmsg_endpoint_info) > > +/** > + * Set the flow control for the remote rpmsg char device. > + */ > +#define RPMSG_GET_OUTGOING_FLOWCONTROL _IOW(0xb5, 0x5, struct rpmsg_endpoint_info) > + > +/** > + * Set the flow control for the local rpmsg char device. > + */ > +#define RPMSG_SET_INCOMING_FLOWCONTROL _IOW(0xb5, 0x6, struct rpmsg_endpoint_info) > + > #endif