From patchwork Tue Jul 7 19:07:48 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Siddharth Gupta X-Patchwork-Id: 11649805 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 2DFFA6C1 for ; Tue, 7 Jul 2020 19:08:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 15C6A206F6 for ; Tue, 7 Jul 2020 19:08:19 +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="SXyzudWM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728607AbgGGTIS (ORCPT ); Tue, 7 Jul 2020 15:08:18 -0400 Received: from mail29.static.mailgun.info ([104.130.122.29]:33401 "EHLO mail29.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728067AbgGGTIS (ORCPT ); Tue, 7 Jul 2020 15:08:18 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1594148898; h=Message-Id: Date: Subject: Cc: To: From: Sender; bh=9IrwGFZJCY5EJx1yIfyu048oORHtxrhYqRHCpxZifu4=; b=SXyzudWMXfdyWfvjDIkFb4d8n1Pr1gcRSSSXjvhOPhmpO19EjGNgU0AggOPauhKvOtdRR9qs 6FLFH7UORX4hKkygPvADUm1pXzTIaAChlOgwTtQZNIAnuDU8gHwf6m6ZYgW5Z2uRQDaMnTuB gkgnsl8n6PxMKOnnTNUFw0DrnOg= X-Mailgun-Sending-Ip: 104.130.122.29 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 smtp-out-n10.prod.us-west-2.postgun.com with SMTP id 5f04c8156e56afc68dc78fd2 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Tue, 07 Jul 2020 19:08:05 GMT Received: by smtp.codeaurora.org (Postfix, from userid 1001) id E06A8C433CB; Tue, 7 Jul 2020 19:08:04 +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 sidgup-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: sidgup) by smtp.codeaurora.org (Postfix) with ESMTPSA id C1B6BC433C8; Tue, 7 Jul 2020 19:08:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org C1B6BC433C8 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 From: Siddharth Gupta To: agross@kernel.org, bjorn.andersson@linaro.org, ohad@wizery.com, corbet@lwn.net Cc: Siddharth Gupta , 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: [PATCH v4 0/2] Add character device interface to remoteproc Date: Tue, 7 Jul 2020 12:07:48 -0700 Message-Id: <1594148870-27276-1-git-send-email-sidgup@codeaurora.org> X-Mailer: git-send-email 2.7.4 Sender: linux-remoteproc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-remoteproc@vger.kernel.org This patch series adds a character device interface to remoteproc framework. Currently there is only a sysfs interface which the userspace clients can use. If a usersapce application crashes after booting the remote processor through the sysfs interface 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 data from disk/flash memory. If the remotefs service crashes, modem still keeps on requesting data which might lead to crash on modem. Even if the service is restarted the file handles modem requested previously would become stale. 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. Changelog: v3 -> v4: - Addressed comments from Mathieu and Arnaud. - Added locks while writing/reading from the automatic-shutdown-on-release bool. - Changed return value when failing to copy to/from userspace. - Changed logic for calling shutdown on release. - Moved around code after the increase of max line length from 80 to 100. - Moved the call adding character device before device_add in rproc_add to add both sysfs and character device interface together. v2 -> v3: - Move booting of remoteproc from open to a write call. - Add ioctl interface for future functionality extension. - Add an ioctl call to default to rproc shutdown on release. v1 -> v2: - Fixed comments from Bjorn and Matthew. Siddharth Gupta (2): remoteproc: Add remoteproc character device interface remoteproc: core: Register the character device interface 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_core.c | 10 ++ drivers/remoteproc/remoteproc_internal.h | 28 ++++ include/linux/remoteproc.h | 5 + include/uapi/linux/remoteproc_cdev.h | 37 ++++++ 8 files changed, 237 insertions(+) create mode 100644 drivers/remoteproc/remoteproc_cdev.c create mode 100644 include/uapi/linux/remoteproc_cdev.h