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 X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2E9C4C83001 for ; Thu, 30 Apr 2020 08:30:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F221720838 for ; Thu, 30 Apr 2020 08:30:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=st.com header.i=@st.com header.b="LbAX5IPl" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726852AbgD3IaP (ORCPT ); Thu, 30 Apr 2020 04:30:15 -0400 Received: from mx08-00178001.pphosted.com ([91.207.212.93]:21498 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726531AbgD3IaP (ORCPT ); Thu, 30 Apr 2020 04:30:15 -0400 Received: from pps.filterd (m0046660.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 03U8MVPW011011; Thu, 30 Apr 2020 10:30:07 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=st.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=STMicroelectronics; bh=OE0tp6+X5tTQDJZQL0I8xkm+cC1qOOa0U5/6s5K6JSc=; b=LbAX5IPlMwEthnL1IMzKAwbxsekznfCygV9FG2jz+zj6MqCUWGZoTSl2iYao4NSWMXbI 3jMd0Lzy4cFCMptZCqA9K5QrzPRQq+65sLeuRNgxcPjI3zqByopW31dEBU/PA2ZjvHjh stzKbtiWhnXeDqh977pXtpZHOjusFBWuSQvICykzi5++xuK6umwEdzeo9ZUscVlL82UM buBddmrVhmkAG76Fjj6uvB9rf+wANywSG5TvBe5t8Z7nvv4FvOGQQY4TNb/XQF/6vx4U 4BCPkvDbc9+sIO7lqBBFybM7i9ONVrs4fJpxuN0K0xrnTGkoFPfx3k18d3zK/0yC4Rai SA== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com with ESMTP id 30mhq6ayw2-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 30 Apr 2020 10:30:07 +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 B1B2F10002A; Thu, 30 Apr 2020 10:30:05 +0200 (CEST) Received: from Webmail-eu.st.com (sfhdag3node1.st.com [10.75.127.7]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 961AF2AD2DD; Thu, 30 Apr 2020 10:30:05 +0200 (CEST) Received: from lmecxl0889.tpe.st.com (10.75.127.49) by SFHDAG3NODE1.st.com (10.75.127.7) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Thu, 30 Apr 2020 10:30:04 +0200 Subject: Re: [PATCH v3 1/2] remoteproc: Add remoteproc character device interface To: Rishabh Bhatnagar , , CC: , , , , , References: <1587492618-15896-1-git-send-email-rishabhb@codeaurora.org> <1587492618-15896-2-git-send-email-rishabhb@codeaurora.org> From: Arnaud POULIQUEN Message-ID: Date: Thu, 30 Apr 2020 10:30:03 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <1587492618-15896-2-git-send-email-rishabhb@codeaurora.org> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.75.127.49] X-ClientProxiedBy: SFHDAG2NODE3.st.com (10.75.127.6) To SFHDAG3NODE1.st.com (10.75.127.7) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138,18.0.676 definitions=2020-04-30_03:2020-04-30,2020-04-30 signatures=0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Rishabh, On 4/21/20 8:10 PM, Rishabh Bhatnagar wrote: > Add the character device interface into remoteproc framework. > This interface can be used in order to boot/shutdown remote > subsystems and provides a basic ioctl based interface to implement > supplementary functionality. An ioctl call is implemented to enable > the shutdown on release feature which will allow remote processors to > be shutdown when the controlling userpsace application crashes or hangs. > Thanks for intruducing Ioctl, this will help for future evolutions. > Signed-off-by: Rishabh Bhatnagar > --- > Documentation/userspace-api/ioctl/ioctl-number.rst | 1 + > drivers/remoteproc/Kconfig | 9 ++ > drivers/remoteproc/Makefile | 1 + > drivers/remoteproc/remoteproc_cdev.c | 143 +++++++++++++++++++++ > drivers/remoteproc/remoteproc_internal.h | 21 +++ > include/linux/remoteproc.h | 3 + > include/uapi/linux/remoteproc_cdev.h | 20 +++ > 7 files changed, 198 insertions(+) > create mode 100644 drivers/remoteproc/remoteproc_cdev.c > create mode 100644 include/uapi/linux/remoteproc_cdev.h > > diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst > index 2e91370..412b2a0 100644 > --- a/Documentation/userspace-api/ioctl/ioctl-number.rst > +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst > @@ -337,6 +337,7 @@ Code Seq# Include File Comments > 0xB4 00-0F linux/gpio.h > 0xB5 00-0F uapi/linux/rpmsg.h > 0xB6 all linux/fpga-dfl.h > +0xB7 all uapi/linux/remoteproc_cdev.h > 0xC0 00-0F linux/usb/iowarrior.h > 0xCA 00-0F uapi/misc/cxl.h > 0xCA 10-2F uapi/misc/ocxl.h > diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig > index de3862c..6374b79 100644 > --- a/drivers/remoteproc/Kconfig > +++ b/drivers/remoteproc/Kconfig > @@ -14,6 +14,15 @@ config REMOTEPROC > > if REMOTEPROC > > +config REMOTEPROC_CDEV > + bool "Remoteproc character device interface" > + help > + Say y here to have a character device interface for Remoteproc > + framework. Userspace can boot/shutdown remote processors through > + this interface. > + > + It's safe to say N if you don't want to use this interface. > + > config IMX_REMOTEPROC > tristate "IMX6/7 remoteproc support" > depends on ARCH_MXC > diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile > index e30a1b1..b7d4f77 100644 > --- a/drivers/remoteproc/Makefile > +++ b/drivers/remoteproc/Makefile > @@ -9,6 +9,7 @@ remoteproc-y += remoteproc_debugfs.o > remoteproc-y += remoteproc_sysfs.o > remoteproc-y += remoteproc_virtio.o > remoteproc-y += remoteproc_elf_loader.o > +obj-$(CONFIG_REMOTEPROC_CDEV) += remoteproc_cdev.o > obj-$(CONFIG_IMX_REMOTEPROC) += imx_rproc.o > obj-$(CONFIG_MTK_SCP) += mtk_scp.o mtk_scp_ipi.o > obj-$(CONFIG_OMAP_REMOTEPROC) += omap_remoteproc.o > diff --git a/drivers/remoteproc/remoteproc_cdev.c b/drivers/remoteproc/remoteproc_cdev.c > new file mode 100644 > index 0000000..65142ec > --- /dev/null > +++ b/drivers/remoteproc/remoteproc_cdev.c > @@ -0,0 +1,143 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Character device interface driver for Remoteproc framework. > + * > + * Copyright (c) 2020, The Linux Foundation. All rights reserved. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include "remoteproc_internal.h" > + > +#define NUM_RPROC_DEVICES 64 > +static dev_t rproc_major; > + > +static ssize_t rproc_cdev_write(struct file *filp, const char __user *buf, > + size_t len, loff_t *pos) > +{ > + struct rproc *rproc = container_of(filp->f_inode->i_cdev, > + struct rproc, char_dev); > + int ret = 0; > + char cmd[10]; > + > + if (!len || len > sizeof(cmd)) > + return -EINVAL; > + > + ret = copy_from_user(cmd, buf, sizeof(cmd)); > + if (ret) > + return -EFAULT; > + > + if (sysfs_streq(cmd, "start")) { > + if (rproc->state == RPROC_RUNNING) > + return -EBUSY; > + > + ret = rproc_boot(rproc); > + if (ret) > + dev_err(&rproc->dev, "Boot failed:%d\n", ret); > + } else if (sysfs_streq(cmd, "stop")) { > + if (rproc->state == RPROC_OFFLINE) > + return -ENXIO; returning ENXIO in this case seems to me no appropriate , what about EPERM or EINVAL (rproc_sysfs) ? > + > + rproc_shutdown(rproc); > + } else { > + dev_err(&rproc->dev, "Unrecognized option\n"); > + ret = -EINVAL; > + } > + > + return ret ? ret : len; > +} > + > +static long rproc_device_ioctl(struct file *filp, unsigned int ioctl, > + unsigned long arg) > +{ > + struct rproc *rproc = container_of(filp->f_inode->i_cdev, > + struct rproc, char_dev); > + void __user *argp = (void __user *)arg; > + int ret; > + bool param; > + > + switch (ioctl) { > + case RPROC_SET_SHUTDOWN_ON_RELEASE: > + ret = copy_from_user(¶m, argp, sizeof(bool)); > + if (ret) { > + dev_err(&rproc->dev, "Data copy from userspace failed\n"); > + return -EINVAL; > + } > + rproc->cdev_put_on_release = param; argp is an void value, where cdev_put_on_release is a bool a check or a conversion seems missing > + break; > + case RPROC_GET_SHUTDOWN_ON_RELEASE: > + ret = copy_to_user(argp, &rproc->cdev_put_on_release, > + sizeof(bool)); > + if (ret) { > + dev_err(&rproc->dev, "Data copy to userspace failed\n"); > + return -EINVAL; > + } > + break; > + default: > + dev_err(&rproc->dev, "Unsupported ioctl\n"); > + return -EINVAL; > + } > + return 0; > +} > + > +static int rproc_cdev_release(struct inode *inode, struct file *filp) > +{ > + struct rproc *rproc = container_of(inode->i_cdev, struct rproc, > + char_dev); > + > + if (rproc->cdev_put_on_release && rproc->state != RPROC_OFFLINE) > + rproc_shutdown(rproc); > + > + return 0; > +} > + > + > +static const struct file_operations rproc_fops = { > + .write = rproc_cdev_write, > + .unlocked_ioctl = rproc_device_ioctl, > + .release = rproc_cdev_release, > +}; > + > +int rproc_char_device_add(struct rproc *rproc) > +{ > + int ret; > + dev_t cdevt; > + > + cdev_init(&rproc->char_dev, &rproc_fops); > + rproc->char_dev.owner = THIS_MODULE; > + > + cdevt = MKDEV(MAJOR(rproc_major), rproc->index); > + ret = cdev_add(&rproc->char_dev, cdevt, 1); > + if (ret < 0) > + goto out; > + > + rproc->dev.devt = cdevt; > +out: > + return ret; > +} > + > +void rproc_char_device_remove(struct rproc *rproc) > +{ > + __unregister_chrdev(MAJOR(rproc->dev.devt), rproc->index, 1, "rproc"); > +} > + > +void __init rproc_init_cdev(void) > +{ > + int ret; > + > + ret = alloc_chrdev_region(&rproc_major, 0, NUM_RPROC_DEVICES, "rproc"); "remoteproc"instead of "rproc" (in line with sysfs and debugfs naming) . > + if (ret < 0) > + pr_err("Failed to alloc rproc_cdev region, err %d\n", ret); > +} > + > +void __exit rproc_exit_cdev(void) > +{ > + unregister_chrdev_region(MKDEV(MAJOR(rproc_major), 0), > + NUM_RPROC_DEVICES); > +} > diff --git a/drivers/remoteproc/remoteproc_internal.h b/drivers/remoteproc/remoteproc_internal.h > index 493ef92..fb9d891 100644 > --- a/drivers/remoteproc/remoteproc_internal.h > +++ b/drivers/remoteproc/remoteproc_internal.h > @@ -47,6 +47,27 @@ struct dentry *rproc_create_trace_file(const char *name, struct rproc *rproc, > int rproc_init_sysfs(void); > void rproc_exit_sysfs(void); > > +#ifdef CONFIG_REMOTEPROC_CDEV > +void rproc_init_cdev(void); > +void rproc_exit_cdev(void); > +int rproc_char_device_add(struct rproc *rproc); > +void rproc_char_device_remove(struct rproc *rproc); > +#else > +static inline void rproc_init_cdev(void) > +{ > +} > +static inline void rproc_exit_cdev(void) > +{ > +} > +static inline int rproc_char_device_add(struct rproc *rproc) > +{ > + return 0; > +} > +static inline void rproc_char_device_remove(struct rproc *rproc) > +{ > +} > +#endif > + > void rproc_free_vring(struct rproc_vring *rvring); > int rproc_alloc_vring(struct rproc_vdev *rvdev, int i); > > diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h > index 16ad666..9bd2ff5 100644 > --- a/include/linux/remoteproc.h > +++ b/include/linux/remoteproc.h > @@ -40,6 +40,7 @@ > #include > #include > #include > +#include > #include > > /** > @@ -514,6 +515,8 @@ struct rproc { > bool auto_boot; > struct list_head dump_segments; > int nb_vdev; > + struct cdev char_dev; > + bool cdev_put_on_release; > }; These parameters are local variables of rproc_cdev. Could be defined in a separate structure. with a pointer in rproc to this structure. > > /** > diff --git a/include/uapi/linux/remoteproc_cdev.h b/include/uapi/linux/remoteproc_cdev.h > new file mode 100644 > index 0000000..3975120 > --- /dev/null > +++ b/include/uapi/linux/remoteproc_cdev.h > @@ -0,0 +1,20 @@ > +/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */ > +/* > + * IOCTLs for Remoteproc's character device interface. > + * > + * Copyright (c) 2020, The Linux Foundation. All rights reserved. > + */ > + > + > +#ifndef _UAPI_REMOTEPROC_CDEV_H_ > +#define _UAPI_REMOTEPROC_CDEV_H_ > + > +#include > +#include > + > +#define RPROC_MAGIC 0xB7 > + > +#define RPROC_SET_SHUTDOWN_ON_RELEASE _IOW(RPROC_MAGIC, 1, int) > +#define RPROC_GET_SHUTDOWN_ON_RELEASE _IOR(RPROC_MAGIC, 2, int) > + > +#endif > IOCTLs should probaly be documented. Thanks, Arnaud