From patchwork Wed Apr 1 00:03:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rishabh Bhatnagar X-Patchwork-Id: 11468491 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D4A8B1667 for ; Wed, 1 Apr 2020 00:04:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9F5A420772 for ; Wed, 1 Apr 2020 00:04:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="V6B+L2rV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731604AbgDAAEM (ORCPT ); Tue, 31 Mar 2020 20:04:12 -0400 Received: from mail27.static.mailgun.info ([104.130.122.27]:40643 "EHLO mail27.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729514AbgDAAEM (ORCPT ); Tue, 31 Mar 2020 20:04:12 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1585699451; h=Message-Id: Date: Subject: Cc: To: From: Sender; bh=ZBJAAaa3TvwvVz/4rY37gGSVlw1f3QzL6lY3lGWRPEg=; b=V6B+L2rVWBsxW0sy+MC86lO4WP0STrC8QMiS5PEHJM3tbtkfUaqsGqZM8i71GAO4/lmI753+ /NG3gFAqHMrC0WHLsgOftYgFSJwYaQ8cfiIdVZg1hubY02qTDT7DOpsBKD0i5J0OPUJgUBCf gGZvXpg5vMjNOrxatp8CJ9fKqMs= X-Mailgun-Sending-Ip: 104.130.122.27 X-Mailgun-Sid: WyI4ZWZiZiIsICJsaW51eC1yZW1vdGVwcm9jQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by mxa.mailgun.org with ESMTP id 5e83da75.7f8c32be4180-smtp-out-n02; Wed, 01 Apr 2020 00:04:05 -0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 0CD62C44788; Wed, 1 Apr 2020 00:04:05 +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 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from rishabhb-linux.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: rishabhb) by smtp.codeaurora.org (Postfix) with ESMTPSA id 99CA7C433D2; Wed, 1 Apr 2020 00:04:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 99CA7C433D2 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=rishabhb@codeaurora.org From: Rishabh Bhatnagar To: linux-kernel@vger.kernel.org, linux-remoteproc@vger.kernel.org, bjorn.andersson@linaro.org Cc: psodagud@codeaurora.org, tsoni@codeaurora.org, sidgup@codeaurora.org, Rishabh Bhatnagar Subject: [PATCH v2 1/2] remoteproc: Add character device interface Date: Tue, 31 Mar 2020 17:03:57 -0700 Message-Id: <1585699438-14394-1-git-send-email-rishabhb@codeaurora.org> X-Mailer: git-send-email 1.9.1 Sender: linux-remoteproc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-remoteproc@vger.kernel.org Add the character device interface for userspace applications. This interface can be used in order to boot up and shutdown remote subsystems. Currently there is only a sysfs interface which the userspace clients can use. If a usersapce application crashes after booting the remote processor does not get any indication about the crash. It might still assume that the application is running. For example modem uses remotefs service to fetch data from disk/flash memory. If the remotefs service crashes, modem keeps on requesting data which might lead to a crash. Adding a character device interface makes the remote processor tightly coupled with the user space application. A crash of the application leads to a close on the file descriptors therefore shutting down the remoteproc. Signed-off-by: Rishabh Bhatnagar --- drivers/remoteproc/Kconfig | 9 +++ drivers/remoteproc/Makefile | 1 + drivers/remoteproc/remoteproc_cdev.c | 100 +++++++++++++++++++++++++++++++ drivers/remoteproc/remoteproc_internal.h | 22 +++++++ include/linux/remoteproc.h | 2 + 5 files changed, 134 insertions(+) create mode 100644 drivers/remoteproc/remoteproc_cdev.c 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..8182bd1 --- /dev/null +++ b/drivers/remoteproc/remoteproc_cdev.c @@ -0,0 +1,100 @@ +// 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 "remoteproc_internal.h" + +#define NUM_RPROC_DEVICES 64 +static dev_t rproc_cdev; +static DEFINE_IDA(cdev_minor_ida); + +static int rproc_cdev_open(struct inode *inode, struct file *file) +{ + struct rproc *rproc; + + rproc = container_of(inode->i_cdev, struct rproc, char_dev); + + if (!rproc) + return -EINVAL; + + if (rproc->state == RPROC_RUNNING) + return -EBUSY; + + return rproc_boot(rproc); +} + +static int rproc_cdev_release(struct inode *inode, struct file *file) +{ + struct rproc *rproc; + + rproc = container_of(inode->i_cdev, struct rproc, char_dev); + + if (!rproc || rproc->state != RPROC_RUNNING) + return -EINVAL; + + rproc_shutdown(rproc); + + return 0; +} + +static const struct file_operations rproc_fops = { + .open = rproc_cdev_open, + .release = rproc_cdev_release, +}; + +int rproc_char_device_add(struct rproc *rproc) +{ + int ret, minor; + dev_t cdevt; + + minor = ida_simple_get(&cdev_minor_ida, 0, NUM_RPROC_DEVICES, + GFP_KERNEL); + if (minor < 0) { + dev_err(&rproc->dev, "%s: No more minor numbers left! rc:%d\n", + __func__, minor); + return -ENODEV; + } + + cdev_init(&rproc->char_dev, &rproc_fops); + rproc->char_dev.owner = THIS_MODULE; + + cdevt = MKDEV(MAJOR(rproc_cdev), minor); + ret = cdev_add(&rproc->char_dev, cdevt, 1); + if (ret < 0) + ida_simple_remove(&cdev_minor_ida, minor); + + rproc->dev.devt = cdevt; + return ret; +} + +void rproc_char_device_remove(struct rproc *rproc) +{ + __unregister_chrdev(MAJOR(rproc->dev.devt), MINOR(rproc->dev.devt), 1, + "rproc"); + ida_simple_remove(&cdev_minor_ida, MINOR(rproc->dev.devt)); +} + +void __init rproc_init_cdev(void) +{ + int ret; + + ret = alloc_chrdev_region(&rproc_cdev, 0, NUM_RPROC_DEVICES, "rproc"); + if (ret < 0) { + pr_err("Failed to alloc rproc_cdev region, err %d\n", ret); + return; + } +} + +void __exit rproc_exit_cdev(void) +{ + __unregister_chrdev(MAJOR(rproc_cdev), 0, NUM_RPROC_DEVICES, "rproc"); +} diff --git a/drivers/remoteproc/remoteproc_internal.h b/drivers/remoteproc/remoteproc_internal.h index 493ef92..28d61a1 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); @@ -63,6 +84,7 @@ struct resource_table *rproc_elf_find_loaded_rsc_table(struct rproc *rproc, struct rproc_mem_entry * rproc_find_carveout_by_name(struct rproc *rproc, const char *name, ...); + static inline int rproc_fw_sanity_check(struct rproc *rproc, const struct firmware *fw) { diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h index 16ad666..c4ca796 100644 --- a/include/linux/remoteproc.h +++ b/include/linux/remoteproc.h @@ -37,6 +37,7 @@ #include #include +#include #include #include #include @@ -514,6 +515,7 @@ struct rproc { bool auto_boot; struct list_head dump_segments; int nb_vdev; + struct cdev char_dev; }; /**