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=-10.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 5959DC433E4 for ; Wed, 15 Jul 2020 20:18:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 34E8E2065D for ; Wed, 15 Jul 2020 20:18:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="eUrje6w1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726761AbgGOUSp (ORCPT ); Wed, 15 Jul 2020 16:18:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48990 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726670AbgGOUSn (ORCPT ); Wed, 15 Jul 2020 16:18:43 -0400 Received: from mail-pj1-x1043.google.com (mail-pj1-x1043.google.com [IPv6:2607:f8b0:4864:20::1043]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B047C08C5DB for ; Wed, 15 Jul 2020 13:18:43 -0700 (PDT) Received: by mail-pj1-x1043.google.com with SMTP id ls15so3645951pjb.1 for ; Wed, 15 Jul 2020 13:18:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=2q3I7QDMdOcMA9wa9UsOqUNLAwlF6nyn2XSA60pRumc=; b=eUrje6w18PkwKTMx/8Zbq4rVkIWQUWnVKjXWyTCwy8eK1GIFyz7L8yTxWcSyKPYGAR sL0TWCH5YGUIDxtwxRRoC31Yj+dNrqLOhS6yLgCu6A47en6iyCc769/d0R1rwj/+y8U8 k0JOFsEDIlxgX/G/gqvTkM3L0J4wg17PrfCd7KMDTivxeRyQhZVvZMv9wmYnJ4s0vrkj mEoiSBwQ/0SlYui17h6Ex48rakkpnthJXVVdifuHFATuR8au9izGHOpVdRojA6j7cfy2 jhvVLE/ROSinYryjpEWUWQCmDxwbYXvMYlaAA4KedrTbFVYvXp+rEjcHSgwIOynEFGdI mTCw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=2q3I7QDMdOcMA9wa9UsOqUNLAwlF6nyn2XSA60pRumc=; b=SEfu/UaVaE/4/P4oEe+61YovXKA0yhenOI//ZmRuRWssIDOhy27vFSdyPzBttCZy4m 8lME9weyD6jLqRIfsl+23i599+T94e3f9Rrq19k0Uv2YPpCS9ZZm9Pm0ebFQjt8Gc20F b2vMsYAC5Fs3tC3c63RYsaLoeQuqIUQalcQcLmuqQnmIPTBlI7dxQf/E1Kq/vOW5oscZ sybNYTUoI2VhoSvuzztwhCRcf8tPUKo8kcuW5DCimkFsG4VZxYM6/zEbg/9aoqG5O542 mOUUq7IqqFKkG8BqQD+Fs6pk2kGC/jJZR9KB9JD+rOHjWLRYt//gwTAljHAtK/+ZUCHy nPPw== X-Gm-Message-State: AOAM532YKYHIrIw8c/WheAF2sz+u+nwP+NU87TaWMAZCs+O1q4jTkbYb J3qSO8rzm1oRbFMl17u3508wdQ== X-Google-Smtp-Source: ABdhPJyQ1PNz4HJZVuPUQnS7Z3goKHvuYpv2/of+ERim7YEk8lh1kDzWFXYrtWUq+KZEcSvyQCxRSg== X-Received: by 2002:a17:90a:2c0e:: with SMTP id m14mr1446415pjd.166.1594844322668; Wed, 15 Jul 2020 13:18:42 -0700 (PDT) Received: from xps15 (S0106002369de4dac.cg.shawcable.net. [68.147.8.254]) by smtp.gmail.com with ESMTPSA id b128sm2814793pfg.114.2020.07.15.13.18.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 15 Jul 2020 13:18:42 -0700 (PDT) Date: Wed, 15 Jul 2020 14:18:39 -0600 From: Mathieu Poirier To: Siddharth Gupta Cc: agross@kernel.org, bjorn.andersson@linaro.org, ohad@wizery.com, corbet@lwn.net, linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, tsoni@codeaurora.org, psodagud@codeaurora.org, rishabhb@codeaurora.org, linux-doc@vger.kernel.org Subject: Re: [PATCH v4 1/2] remoteproc: Add remoteproc character device interface Message-ID: <20200715201839.GA3204081@xps15> References: <1594148870-27276-1-git-send-email-sidgup@codeaurora.org> <1594148870-27276-2-git-send-email-sidgup@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1594148870-27276-2-git-send-email-sidgup@codeaurora.org> Sender: linux-remoteproc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-remoteproc@vger.kernel.org On Tue, Jul 07, 2020 at 12:07:49PM -0700, Siddharth Gupta 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. > > Signed-off-by: Rishabh Bhatnagar > Signed-off-by: Siddharth Gupta > --- > Documentation/userspace-api/ioctl/ioctl-number.rst | 1 + > drivers/remoteproc/Kconfig | 9 ++ > drivers/remoteproc/Makefile | 1 + > drivers/remoteproc/remoteproc_cdev.c | 146 +++++++++++++++++++++ > drivers/remoteproc/remoteproc_internal.h | 28 ++++ > include/linux/remoteproc.h | 5 + > include/uapi/linux/remoteproc_cdev.h | 37 ++++++ > 7 files changed, 227 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 59472cd..2a19883 100644 > --- a/Documentation/userspace-api/ioctl/ioctl-number.rst > +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst > @@ -339,6 +339,7 @@ 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 c4d1731..652060f 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 the 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 e8b886e..311ae3f 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-$(CONFIG_INGENIC_VPU_RPROC) += ingenic_rproc.o > obj-$(CONFIG_MTK_SCP) += mtk_scp.o mtk_scp_ipi.o > diff --git a/drivers/remoteproc/remoteproc_cdev.c b/drivers/remoteproc/remoteproc_cdev.c > new file mode 100644 > index 0000000..8a0eb47 > --- /dev/null > +++ b/drivers/remoteproc/remoteproc_cdev.c > @@ -0,0 +1,146 @@ > +// 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 Alphabetical order please. > + > +#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_RUNNING) > + return -EINVAL; > + > + 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 = compat_ptr(arg); > + int ret; > + int32_t param; > + > + switch (ioctl) { > + case RPROC_SET_SHUTDOWN_ON_RELEASE: > + ret = copy_from_user(¶m, argp, sizeof(int32_t)); > + if (ret) { > + dev_err(&rproc->dev, "Data copy from userspace failed\n"); > + return -EFAULT; > + } > + mutex_lock(&rproc->lock); > + rproc->cdev_put_on_release = param ? true : false; > + mutex_unlock(&rproc->lock); > + break; > + case RPROC_GET_SHUTDOWN_ON_RELEASE: > + mutex_lock(&rproc->lock); > + ret = copy_to_user(argp, &rproc->cdev_put_on_release, sizeof(bool)); > + mutex_unlock(&rproc->lock); > + if (ret) { > + dev_err(&rproc->dev, "Data copy to userspace failed\n"); > + return -EFAULT; > + } > + 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); > + bool release; > + > + mutex_lock(&rproc->lock); > + release = rproc->cdev_put_on_release; > + mutex_unlock(&rproc->lock); > + > + if (release && rproc->state == RPROC_RUNNING) I think the state of the processor should also be acquired when the lock is held. There is still a chance ->state can change between the time the lock is released and rproc_shutdown() is called but that's a known problem for which patches have been sent out. > + rproc_shutdown(rproc); > + > + return 0; > +} > + > +static const struct file_operations rproc_fops = { > + .write = rproc_cdev_write, > + .compat_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(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(rproc_major, rproc->index, 1, "remoteproc"); > +} > + > +void __init rproc_init_cdev(void) > +{ > + int ret; > + > + ret = alloc_chrdev_region(&rproc_major, 0, NUM_RPROC_DEVICES, "remoteproc"); > + 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(rproc_major, 0), NUM_RPROC_DEVICES); Please go back to the comment I made on this during my last review and respin. > +} > diff --git a/drivers/remoteproc/remoteproc_internal.h b/drivers/remoteproc/remoteproc_internal.h > index 4ba7cb5..f091ddc 100644 > --- a/drivers/remoteproc/remoteproc_internal.h > +++ b/drivers/remoteproc/remoteproc_internal.h > @@ -47,6 +47,34 @@ extern struct class rproc_class; > 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) > +{ > +} > + > +/* > + * The character device interface is an optional feature, if it is not enabled > + * the function should not return an error. > + */ > +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 e7b7bab..669cbfb 100644 > --- a/include/linux/remoteproc.h > +++ b/include/linux/remoteproc.h > @@ -40,6 +40,7 @@ > #include > #include > #include > +#include Move this above completion.h With all of the above modifications: Reviewed-by: Mathieu Poirier > #include > > /** > @@ -488,6 +489,8 @@ struct rproc_dump_segment { > * @auto_boot: flag to indicate if remote processor should be auto-started > * @dump_segments: list of segments in the firmware > * @nb_vdev: number of vdev currently handled by rproc > + * @char_dev: character device of the rproc > + * @cdev_put_on_release: flag to indicate if remoteproc should be shutdown on @char_dev release > */ > struct rproc { > struct list_head node; > @@ -523,6 +526,8 @@ struct rproc { > int nb_vdev; > u8 elf_class; > u16 elf_machine; > + struct cdev char_dev; > + bool cdev_put_on_release; > }; > > /** > diff --git a/include/uapi/linux/remoteproc_cdev.h b/include/uapi/linux/remoteproc_cdev.h > new file mode 100644 > index 0000000..c43768e > --- /dev/null > +++ b/include/uapi/linux/remoteproc_cdev.h > @@ -0,0 +1,37 @@ > +/* 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 > + > +/* > + * The RPROC_SET_SHUTDOWN_ON_RELEASE ioctl allows to enable/disable the shutdown of a remote > + * processor automatically when the controlling userpsace closes the char device interface. > + * > + * input parameter: integer > + * 0 : disable automatic shutdown > + * other : enable automatic shutdown > + */ > +#define RPROC_SET_SHUTDOWN_ON_RELEASE _IOW(RPROC_MAGIC, 1, __s32) > + > +/* > + * The RPROC_GET_SHUTDOWN_ON_RELEASE ioctl gets information about whether the automatic shutdown of > + * a remote processor is enabled or disabled when the controlling userspace closes the char device > + * interface. > + * > + * output parameter: integer > + * 0 : automatic shutdown disable > + * other : automatic shutdown enable > + */ > +#define RPROC_GET_SHUTDOWN_ON_RELEASE _IOR(RPROC_MAGIC, 2, __s32) > + > +#endif > -- > Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, > a Linux Foundation Collaborative Project >