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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 64DD3C433FE for ; Mon, 11 Oct 2021 12:53:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4865D60E9C for ; Mon, 11 Oct 2021 12:53:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236708AbhJKMzU (ORCPT ); Mon, 11 Oct 2021 08:55:20 -0400 Received: from mx08-00178001.pphosted.com ([91.207.212.93]:37874 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S230061AbhJKMzS (ORCPT ); Mon, 11 Oct 2021 08:55:18 -0400 Received: from pps.filterd (m0046661.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 19B9GVev022125; Mon, 11 Oct 2021 14:53:17 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foss.st.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=selector1; bh=D917K3Q1knSyVA1O8QE0bgZaxDjZWp8DN2uOU/as1g0=; b=M1gSDcan9lDvgfT74iJlLyn2Jfa6gQ0I7GiP5oyGbEkbMwcP/32QfD9lmPkSdRbbkRi1 N3kBcNHgjSwk8aWsYZ+XO3ET+9A3T4kfxPBsmW/p0HBbHp6h+1THjEceMx4pLbOJywep BEagb9BKz4VYBxg98ZINDIvvY54yBeE7nf30r4Frv0s7V9swP+KAva7N0CzJcaioY8Y0 1QqTg7JluZhbXFtOviKQQmvd9pWAnOgWly/K+68B08UawtCb3JYg2L0FAqGbTTHvgBjG aS850x4rhlLBUYTuTEaoKFMqKyq5JU5UlJOR8g82WDtIoSg7ASfVWS4DEoxUnpkgjw3d Hg== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com with ESMTP id 3bmd35u1af-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 11 Oct 2021 14:53:17 +0200 Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 8CF5710002A; Mon, 11 Oct 2021 14:53:16 +0200 (CEST) Received: from Webmail-eu.st.com (sfhdag2node2.st.com [10.75.127.5]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 7F16B226FAB; Mon, 11 Oct 2021 14:53:16 +0200 (CEST) Received: from lmecxl0889.lme.st.com (10.75.127.50) by SFHDAG2NODE2.st.com (10.75.127.5) with Microsoft SMTP Server (TLS) id 15.0.1497.18; Mon, 11 Oct 2021 14:53:15 +0200 Subject: Re: [PATCH v3] rpmsg: ctrl: Introduce new RPMSG_CREATE/RELEASE_DEV_IOCTL controls To: Bjorn Andersson CC: Ohad Ben-Cohen , Mathieu Poirier , , , References: <20210712132303.25058-1-arnaud.pouliquen@foss.st.com> From: Arnaud POULIQUEN Message-ID: <277171bf-5947-9d1b-6ad5-e80dc15c4cc1@foss.st.com> Date: Mon, 11 Oct 2021 14:53:15 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.75.127.50] X-ClientProxiedBy: SFHDAG2NODE3.st.com (10.75.127.6) To SFHDAG2NODE2.st.com (10.75.127.5) X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.182.1,Aquarius:18.0.790,Hydra:6.0.391,FMLib:17.0.607.475 definitions=2021-10-11_04,2021-10-07_02,2020-04-07_01 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/9/21 2:25 AM, Bjorn Andersson wrote: > On Mon 12 Jul 06:23 PDT 2021, Arnaud Pouliquen wrote: > >> Allow the user space application to create and release an rpmsg device >> by adding RPMSG_CREATE_DEV_IOCTL and RPMSG_RELEASE_DEV_IOCTL ioctrls to >> the /dev/rpmsg_ctrl interface >> > > With > https://lore.kernel.org/linux-remoteproc/CAHk-=wgea9bo-j4+LAvZF7OKPAXKqrGgiBAhXTJ3Jv5JAZgA+A@mail.gmail.com/ > and > https://lore.kernel.org/linux-arm-msm/1609958656-15064-1-git-send-email-hemantk@codeaurora.org/ > in mind, I would like some concrete examples of when and how this is > going to be used. > > > Also, as I said previously, this would have been better to put together > with the split out of rpmsg_ctrl, because afaict this is the only reason > for doing that. Or am I simply missing something? This as been done by steps to ease the review. Any way, these controls also require, to be usable for the rpmsg_char, the implementation of the rpmsg-raw channel in the rpmsg_char. Should i squash the 3 patchsets in one and add concrete examples in cover letter? > >> The RPMSG_CREATE_DEV_IOCTL Ioctl can be used to instantiate a local rpmsg >> device. >> Depending on the back-end implementation, the associated rpmsg driver is >> probed and a NS announcement can be sent to the remote processor. >> > > So, does this imply that in order to spawn a new rpmsg_char from the > host side, I would use RPMSG_CREATE_DEV_IOCTL and to open a channel > announced by the remote I would use RPMSG_CREATE_EPT_IOCTL? No, if announced by the remote side the rpmsg_char dev should be automatically probed by the virtio bus. The RPMSG_CREATE_EPT_IOCTL is the legacy control that is used by QCOM drivers to creates the cdev. It doesn't really make sense for the virtio backend, as virtio is based on a rpmsg channel that is associated to a rpmsg device. The only use case I have in mind would be to create endpoint without channel but using fixed addresses. No concrete use case identified in ST Microelectronics for hardcoded endpoint addresses. > >> The RPMSG_RELEASE_DEV_IOCTL allows the user application to release a >> rpmsg device created either by the remote processor or with the >> RPMSG_CREATE_DEV_IOCTL call. > > Is this a side effect, bug or a feature? Both a side effect but also a feature to remove a channel from the initiative of the user application. Regards, Arnaud > > Regards, > Bjorn > >> Depending on the back-end implementation, the associated rpmsg driver is >> removed and a NS destroy rpmsg can be sent to the remote processor. >> >> Suggested-by: Mathieu Poirier >> Signed-off-by: Arnaud Pouliquen >> Reviewed-by: Mathieu Poirier >> --- >> update from V2 >> - add Reviewed-by: Mathieu Poirier >> - rebased on kernel V.14-rc1 + >> series V5 Restructure the rpmsg char to decorrelate the control part [1] >> >> >> [1] https://patchwork.kernel.org/project/linux-remoteproc/list/?series=514017 >> >> --- >> drivers/rpmsg/rpmsg_ctrl.c | 37 +++++++++++++++++++++++++++++++++---- >> include/uapi/linux/rpmsg.h | 10 ++++++++++ >> 2 files changed, 43 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/rpmsg/rpmsg_ctrl.c b/drivers/rpmsg/rpmsg_ctrl.c >> index eeb1708548c1..cb19e32d05e1 100644 >> --- a/drivers/rpmsg/rpmsg_ctrl.c >> +++ b/drivers/rpmsg/rpmsg_ctrl.c >> @@ -23,6 +23,7 @@ >> #include >> >> #include "rpmsg_char.h" >> +#include "rpmsg_internal.h" >> >> static dev_t rpmsg_major; >> >> @@ -37,11 +38,13 @@ static DEFINE_IDA(rpmsg_minor_ida); >> * @rpdev: underlaying rpmsg device >> * @cdev: cdev for the ctrl device >> * @dev: device for the ctrl device >> + * @ctrl_lock: serialize the ioctrls. >> */ >> struct rpmsg_ctrldev { >> struct rpmsg_device *rpdev; >> struct cdev cdev; >> struct device dev; >> + struct mutex ctrl_lock; >> }; >> >> static int rpmsg_ctrldev_open(struct inode *inode, struct file *filp) >> @@ -70,9 +73,8 @@ static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd, >> void __user *argp = (void __user *)arg; >> struct rpmsg_endpoint_info eptinfo; >> struct rpmsg_channel_info chinfo; >> - >> - if (cmd != RPMSG_CREATE_EPT_IOCTL) >> - return -EINVAL; >> + struct rpmsg_device *rpdev; >> + int ret = 0; >> >> if (copy_from_user(&eptinfo, argp, sizeof(eptinfo))) >> return -EFAULT; >> @@ -82,7 +84,33 @@ static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd, >> chinfo.src = eptinfo.src; >> chinfo.dst = eptinfo.dst; >> >> - return rpmsg_chrdev_eptdev_create(ctrldev->rpdev, &ctrldev->dev, chinfo); >> + mutex_lock(&ctrldev->ctrl_lock); >> + switch (cmd) { >> + case RPMSG_CREATE_EPT_IOCTL: >> + ret = rpmsg_chrdev_eptdev_create(ctrldev->rpdev, &ctrldev->dev, chinfo); >> + break; >> + >> + case RPMSG_CREATE_DEV_IOCTL: >> + rpdev = rpmsg_create_channel(ctrldev->rpdev, &chinfo); >> + if (!rpdev) { >> + dev_err(&ctrldev->dev, "failed to create %s channel\n", chinfo.name); >> + ret = -ENXIO; >> + } >> + break; >> + >> + case RPMSG_RELEASE_DEV_IOCTL: >> + ret = rpmsg_release_channel(ctrldev->rpdev, &chinfo); >> + if (ret) >> + dev_err(&ctrldev->dev, "failed to release %s channel (%d)\n", >> + chinfo.name, ret); >> + break; >> + >> + default: >> + ret = -EINVAL; >> + } >> + mutex_unlock(&ctrldev->ctrl_lock); >> + >> + return ret; >> }; >> >> static const struct file_operations rpmsg_ctrldev_fops = { >> @@ -119,6 +147,7 @@ static int rpmsg_ctrldev_probe(struct rpmsg_device *rpdev) >> device_initialize(dev); >> dev->parent = &rpdev->dev; >> >> + mutex_init(&ctrldev->ctrl_lock); >> cdev_init(&ctrldev->cdev, &rpmsg_ctrldev_fops); >> ctrldev->cdev.owner = THIS_MODULE; >> >> diff --git a/include/uapi/linux/rpmsg.h b/include/uapi/linux/rpmsg.h >> index f5ca8740f3fb..1637e68177d9 100644 >> --- a/include/uapi/linux/rpmsg.h >> +++ b/include/uapi/linux/rpmsg.h >> @@ -33,4 +33,14 @@ struct rpmsg_endpoint_info { >> */ >> #define RPMSG_DESTROY_EPT_IOCTL _IO(0xb5, 0x2) >> >> +/** >> + * Instantiate a new local rpmsg service device. >> + */ >> +#define RPMSG_CREATE_DEV_IOCTL _IOW(0xb5, 0x3, struct rpmsg_endpoint_info) >> + >> +/** >> + * Release a local rpmsg device. >> + */ >> +#define RPMSG_RELEASE_DEV_IOCTL _IOW(0xb5, 0x4, struct rpmsg_endpoint_info) >> + >> #endif >> -- >> 2.17.1 >>