Received: by 2002:a05:6902:102b:0:0:0:0 with SMTP id x11csp79044ybt; Tue, 30 Jun 2020 15:13:42 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwrIchIIYRvPUhTK0gwSxywNOyi05TrslyFQWINeGSjO6GJAHZeOINp6TwBpYQowk44UOty X-Received: by 2002:a50:d501:: with SMTP id u1mr25502078edi.159.1593554791635; Tue, 30 Jun 2020 15:06:31 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1593554791; cv=none; d=google.com; s=arc-20160816; b=QdUTRAiGDJbvyEE4Nf2/QJB2Qlwu/XxK6Vr0x6yTtANgXdjy/ArcrAAZjDPn6Yij6s IuCpOR5WjUZZDeOURUfPjuEmsVZuLNK+1Nuc2jVpW6ZZZPBiXOqzg1BX7az+pBrBWI5X eANbi0IvErvAnXvTWT6oXW5LXO91sEWQH03veAko5k6mX6kqD0FkVwzqh3ynUGj41Qmk UDf+p1KhHdrA4Ndhyvd42xiSOO90lb1bDUQGoCdu9nDG7nJQpvX7G7sTI/d+Jjkac0Mk lpdUs8FXALMdZxqWC6wT/KjZcvmu0p9ode+musySGGtwMYeXpuGIMzUSWDGyoiZfyEgh Ws4Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-language :content-transfer-encoding:in-reply-to:mime-version:user-agent:date :message-id:from:references:cc:to:subject:dmarc-filter :dkim-signature; bh=1i8M/sNwdLERiaBp02XBSSbUjMTGVJbBimX0448lpCE=; b=JNC4bW0nrOxaa9R4wslZFXiFHU81iKr8+p6wct/PJulQt8iJKF1YOQ1glmGGDq7VbR ZWlKIjl36F/TduWmgxep6hGG/MzCSi2hzPTQyqIGjWIfDaHnYXrqJtTa2HfXUHZKJY3h TXwLxHHg96FhCxr78Mrd+ANsr3lZGjtCCXs5/aa8YVoY21JY5HX3IwaP9+VkUTnAqH5e LQAPOghWggE5UHekgvBFAXeulDQpdOVd4mb6gdcG4HOVh8h34UvHGk/LB7sMBUTUgc7S fi1WArLnM3YIKtTMQnD1kuyMGFfzQ3w0pKxM6s4OoMoxchM8iDaQxH4TrP7AQM7AKq6N ZOhg== ARC-Authentication-Results: i=1; mx.google.com; dkim=fail header.i=@mg.codeaurora.org header.s=smtp header.b=ABBFLq27; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id h1si2499958ejc.200.2020.06.30.15.06.08; Tue, 30 Jun 2020 15:06:31 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=fail header.i=@mg.codeaurora.org header.s=smtp header.b=ABBFLq27; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726156AbgF3WCv (ORCPT + 99 others); Tue, 30 Jun 2020 18:02:51 -0400 Received: from m43-7.mailgun.net ([69.72.43.7]:23499 "EHLO m43-7.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726033AbgF3WCv (ORCPT ); Tue, 30 Jun 2020 18:02:51 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1593554569; h=Content-Transfer-Encoding: Content-Type: In-Reply-To: MIME-Version: Date: Message-ID: From: References: Cc: To: Subject: Sender; bh=1i8M/sNwdLERiaBp02XBSSbUjMTGVJbBimX0448lpCE=; b=ABBFLq27X6MQgqMb4Yf7Mtc7bARXsNU0XORyN9XwcahwH1Gh3Y1YtK04YNy9gCZSsZOPTOLn rJsUtbQgI8czbeTBgFIvABpgiDzl4/CYQqfXj+R+0u5iIuPu8AJQEWF4afgIjP5TmdWzHNOM +hI185NswNBzN6eImSSVCaO8vuU= X-Mailgun-Sending-Ip: 69.72.43.7 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n09.prod.us-west-2.postgun.com with SMTP id 5efbb681e144dd511562ddcc (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Tue, 30 Jun 2020 22:02:41 GMT Received: by smtp.codeaurora.org (Postfix, from userid 1001) id E1A50C43391; Tue, 30 Jun 2020 22:02:40 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-caf-mail-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=2.0 tests=ALL_TRUSTED,SPF_NONE, URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from [192.168.1.10] (cpe-70-95-5-60.san.res.rr.com [70.95.5.60]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: sidgup) by smtp.codeaurora.org (Postfix) with ESMTPSA id D2F97C433C8; Tue, 30 Jun 2020 22:02:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org D2F97C433C8 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=none smtp.mailfrom=sidgup@codeaurora.org Subject: Re: [PATCH v3 1/2] remoteproc: Add remoteproc character device interface To: Arnaud POULIQUEN , "rishabhb@codeaurora.org" Cc: "linux-remoteproc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "bjorn.andersson@linaro.org" , "mathieu.poirier@linaro.org" , "ohad@wizery.com" , "tsoni@codeaurora.org" , "psodagud@codeaurora.org" , "linux-remoteproc-owner@vger.kernel.org" References: <1587492618-15896-1-git-send-email-rishabhb@codeaurora.org> <1587492618-15896-2-git-send-email-rishabhb@codeaurora.org> <3738198d-53d4-2fe6-a92b-2db0cd0afa68@st.com> <83c70517-32e4-9ce0-e1b4-2ed7a8b5c506@codeaurora.org> <94541ff3-ba34-3a08-f989-6e1a0a88fbf2@st.com> From: Siddharth Gupta Message-ID: Date: Tue, 30 Jun 2020 15:02:38 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: <94541ff3-ba34-3a08-f989-6e1a0a88fbf2@st.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/30/2020 12:43 AM, Arnaud POULIQUEN wrote: > > On 6/30/20 7:38 AM, Siddharth Gupta wrote: >> On 6/17/2020 1:44 AM, Arnaud POULIQUEN wrote: >>> On 6/16/20 9:56 PM, rishabhb@codeaurora.org wrote: >>>> On 2020-04-30 01:30, Arnaud POULIQUEN wrote: >>>>> 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) ? >> I think EPERM would indicate the operation is not permitted on the >> device, and >> EINVAL would indicate that the command/string they wrote to the char device >> is not a valid command/string. I guess even ENXIO may not be appropriate? >> >> In that case we could use EHOSTDOWN or ESHUTDOWN, thoughts? > Regarding remoteproc_sysfs.c[1], seems that the -EINVAL return would be coherent. Okay sure. > It would probably also be better to replace your condition with > if (rproc->state != RPROC_RUNNING) Will do. > > > [1] https://elixir.bootlin.com/linux/latest/source/drivers/remoteproc/remoteproc_sysfs.c#L104 > > Regards, > Arnaud > >> Thanks, >> Sid >> >>>>>> + >>>>>> + 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. >>>> I have added documentation to >>>> Documentation/userspace-api/ioctl/ioctl-number.rst >>>> Is there another place where I need to add documentation for this? >>> Could you add in this file comments that describe >>> the IOCTL usage and associated parameter? >>> >>> Regards, >>> Arnaud I don't see any for of comments that describe in detail the IOCTL usage, i.e., input parameters, etc. Could you provide an example so I can follow it? If not, should I instead put them in Documentation/remoteproc.txt? Thanks, Sid >>> >>>>> Thanks, >>>>> Arnaud