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=-6.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 14CE8C3B18F for ; Fri, 14 Feb 2020 09:36:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CC08124649 for ; Fri, 14 Feb 2020 09:36:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="qv1aWnVk" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729074AbgBNJgE (ORCPT ); Fri, 14 Feb 2020 04:36:04 -0500 Received: from mail-qk1-f193.google.com ([209.85.222.193]:39704 "EHLO mail-qk1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728513AbgBNJgE (ORCPT ); Fri, 14 Feb 2020 04:36:04 -0500 Received: by mail-qk1-f193.google.com with SMTP id w15so8569322qkf.6; Fri, 14 Feb 2020 01:36:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=oa5NDVj7Ww7HISYPz7pS4O1dMmAYIYvs6C5w/rOHWLk=; b=qv1aWnVkEHdBsaGWDkL0jhE/FUY/uu6Hf83IozRDZ8/USWVkcM1b3x5WxADaYIJVf0 eI9hqdqOtWlar6fkWd/zA7alEA1jU4jZi+SzVdBo3OT4sGRJXv1cRNK1ifAY40NYl/q1 RbMihHzBpuzETJ7pvrdrExhMLmcT88xh3/Ha4EpWvxKbJuCti0nHlQWZ/AqmSbQM11Lq TDUw5gnUGz86gAbjIVLZ7SgL9HkNmTUNylRH7O0wUBfXPwWlIb47FPwAnAFm1X525bWY QsisSCSp4XReAE/W8fZdAj0ky2+VqE4DqmY6q00pxC5ZKk46S0943nqxxJEtrdiK624c 5EFQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=oa5NDVj7Ww7HISYPz7pS4O1dMmAYIYvs6C5w/rOHWLk=; b=O7B6bLg3mRobwcQv7sZIXur4d0RpA25oKqvXgxisw5MY0k1YNLV1dWu4TWeFQ8M1yb FBHybog/cal599LCW0wRO5RcICINPoBKkRyh3wt4m+UGrKKmtrv93hNPD8UdFRIk9Aq8 wfzt1C4HXC6KtJ4qA7u6qkFD41ACVvjjnW+oB5umVDS8EZzuxLpQ0VfeSXmffJrojzZs yfUYgDIkD7mvrYzjWCiaDV4qe9jFH8x1vfGePdSC7G3sD/dvoNd3O3f23XHU3soJ5ZKH XsNp9jOzQjPIaVHXrbDv8GUwCyg/W4/Du9dhQjAQMcmhBkPxCl7R4k+BBEVAflvrYziz R2mg== X-Gm-Message-State: APjAAAXII74X0mypSc5q9aRaIxMaCDygxz/UIWsNMFAVZ1MBVU12xf61 W37ID2WdtWXHZdCG83fSsPG1vekuhrrz0Z0YjGg= X-Google-Smtp-Source: APXvYqyHsNKe8cE7KTCOSuiuGIQ0n7i20+XRZLzrumHlIYQqnDuttK9oecRRmKAsLDwKlsPchqhCiQuZ5YiTc9gV/50= X-Received: by 2002:a37:b744:: with SMTP id h65mr1665365qkf.85.1581672961675; Fri, 14 Feb 2020 01:36:01 -0800 (PST) MIME-Version: 1.0 References: <20200214062637.216209-1-evanbenn@chromium.org> <20200214172512.2.I7c8247c29891a538f258cb47828d58acf22c95a2@changeid> In-Reply-To: <20200214172512.2.I7c8247c29891a538f258cb47828d58acf22c95a2@changeid> From: Enric Balletbo Serra Date: Fri, 14 Feb 2020 10:35:49 +0100 Message-ID: Subject: Re: [PATCH 2/2] watchdog: Add new arm_smc_wdt watchdog driver To: Evan Benn Cc: LKML , jwerner@chromium.org, Bjorn Andersson , Guenter Roeck , Mauro Carvalho Chehab , Marcin Juszkiewicz , Catalin Marinas , Olof Johansson , Leonard Crestez , Jonathan Cameron , Dinh Nguyen , Linux ARM , Greg Kroah-Hartman , Will Deacon , linux-watchdog@vger.kernel.org, Rob Herring , Wim Van Sebroeck , =?UTF-8?B?Q2zDqW1lbnQgUMOpcm9u?= , Shawn Guo , "David S. Miller" , Anson Huang Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-watchdog-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org Hi Evan and Julius, Many thanks for sending this upstream, I have some trivial comments, especially the license one, other than that, the driver looks good to me. Missatge de Evan Benn del dia dv., 14 de febr. 2020 a les 7:28: > > From: Julius Werner > > This patch adds a stub watchdog driver that can be used on ARM systems > with a Secure Monitor firmware to forward watchdog operations to > firmware via a Secure Monitor Call. This may be useful for platforms > using TrustZone that want the Secure Monitor firmware to have the final > control over the watchdog. > > Signed-off-by: Julius Werner > Signed-off-by: Evan Benn > --- > > MAINTAINERS | 1 + > arch/arm64/configs/defconfig | 1 + > drivers/watchdog/Kconfig | 12 +++ > drivers/watchdog/Makefile | 1 + > drivers/watchdog/arm_smc_wdt.c | 191 +++++++++++++++++++++++++++++++++ > 5 files changed, 206 insertions(+) > create mode 100644 drivers/watchdog/arm_smc_wdt.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index 5c45536e1177..71df3c110fdb 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -1426,6 +1426,7 @@ M: Julius Werner > R: Evan Benn > S: Maintained > F: devicetree/bindings/watchdog/arm,smc-wdt.yaml > +F: drivers/watchdog/arm_smc_wdt.c > > ARM SMMU DRIVERS > M: Will Deacon > diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig > index b2f667307f82..8527db9e92a6 100644 > --- a/arch/arm64/configs/defconfig > +++ b/arch/arm64/configs/defconfig > @@ -451,6 +451,7 @@ CONFIG_QCOM_TSENS=3Dy > CONFIG_UNIPHIER_THERMAL=3Dy > CONFIG_WATCHDOG=3Dy > CONFIG_ARM_SP805_WATCHDOG=3Dy > +CONFIG_ARM_SMC_WATCHDOG=3Dy > CONFIG_S3C2410_WATCHDOG=3Dy > CONFIG_DW_WATCHDOG=3Dy > CONFIG_SUNXI_WATCHDOG=3Dm > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index cec868f8db3f..0f7f93342051 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -857,6 +857,18 @@ config DIGICOLOR_WATCHDOG > To compile this driver as a module, choose M here: the > module will be called digicolor_wdt. > > +config ARM_SMC_WATCHDOG > + tristate "ARM Secure Monitor Call based watchdog support" > + depends on ARM || ARM64 Looks like this driver is OF only, so add a dependency on CONFIG_OF > + select WATCHDOG_CORE > + help > + Say Y here to include support for a watchdog timer > + implemented by the EL3 Secure Monitor on ARM platforms. > + Requires firmware support. > + To compile this driver as a module, choose M here: the > + module will be called arm_smc_wdt. > + > + > config LPC18XX_WATCHDOG > tristate "LPC18xx/43xx Watchdog" > depends on ARCH_LPC18XX || COMPILE_TEST > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > index 2ee352bf3372..a1e6d83a7659 100644 > --- a/drivers/watchdog/Makefile > +++ b/drivers/watchdog/Makefile > @@ -92,6 +92,7 @@ obj-$(CONFIG_STM32_WATCHDOG) +=3D stm32_iwdg.o > obj-$(CONFIG_UNIPHIER_WATCHDOG) +=3D uniphier_wdt.o > obj-$(CONFIG_RTD119X_WATCHDOG) +=3D rtd119x_wdt.o > obj-$(CONFIG_SPRD_WATCHDOG) +=3D sprd_wdt.o > +obj-$(CONFIG_ARM_SMC_WATCHDOG) +=3D arm_smc_wdt.o > obj-$(CONFIG_PM8916_WATCHDOG) +=3D pm8916_wdt.o > > # X86 (i386 + ia64 + x86_64) Architecture > diff --git a/drivers/watchdog/arm_smc_wdt.c b/drivers/watchdog/arm_smc_wd= t.c > new file mode 100644 > index 000000000000..58e7294136ef > --- /dev/null > +++ b/drivers/watchdog/arm_smc_wdt.c > @@ -0,0 +1,191 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * ARM Secure Monitor Call watchdog driver > + * > + * Copyright 2018 The Chromium OS Authors. All rights reserved. > + * > + * Julius Werner > + * When adding new files to the kernel, use the regular Google copyright header to them. The main reason for this is that there=E2=80=98s no concept= of =E2=80=9CThe Chromium OS Authors=E2=80=9D outside of Chromium OS project, s= ince it refers to the AUTHORS file that isn=E2=80=99t bundled with the kernel. [1] In this case, it should be something like this: /* SPDX-License-Identifier: GPL-2.0-only */ /* * ARM Secure Monitor Call watchdog driver * * Copyright 2020 Google LLC. */ See: https://chromium.googlesource.com/chromiumos/docs/+/master/kernel_faq.= md > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + * Based on mtk_wdt.c Remove the license boilerplate, it is implicit in the SPDX tag. The reasoning is to avoid mismatches like what happens here. You are licensing the file as GPL-2.0-only but the boilerplate is GPL-2.0-or-later. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#define DRV_NAME "arm_smc_wdt" > +#define DRV_VERSION "1.0" > + > +#define SMCWD_FUNC_ID 0x82003d06 > + > +enum smcwd_call { > + SMCWD_INFO =3D 0, > + SMCWD_SET_TIMEOUT =3D 1, > + SMCWD_ENABLE =3D 2, > + SMCWD_PET =3D 3, > +}; > + > +static bool nowayout =3D WATCHDOG_NOWAYOUT; > +static unsigned int timeout; > + > +static int smcwd_call(enum smcwd_call call, unsigned long arg, > + struct arm_smccc_res *res) > +{ > + struct arm_smccc_res local_res; > + > + if (!res) > + res =3D &local_res; > + > + arm_smccc_smc(SMCWD_FUNC_ID, call, arg, 0, 0, 0, 0, 0, res); > + > + if ((int)res->a0 =3D=3D PSCI_RET_NOT_SUPPORTED) Is this cast really needed? > + return -ENOTSUPP; > + if ((int)res->a0 =3D=3D PSCI_RET_INVALID_PARAMS) ditto > + return -EINVAL; > + if ((int)res->a0 < 0) ditto > + return -EIO; > + return res->a0; > +} > + > +static int smcwd_ping(struct watchdog_device *wdd) > +{ > + return smcwd_call(SMCWD_PET, 0, NULL); > +} > + > +static int smcwd_set_timeout(struct watchdog_device *wdd, > + unsigned int timeout) nit: Alignment should match open parenthesis ( if you want to follow what checkpatch says with the --strict option ) > +{ > + int res; > + > + res =3D smcwd_call(SMCWD_SET_TIMEOUT, timeout, NULL); > + if (!res) > + wdd->timeout =3D timeout; > + return res; > +} > + > +static int smcwd_stop(struct watchdog_device *wdd) > +{ > + return smcwd_call(SMCWD_ENABLE, 0, NULL); > +} > + > +static int smcwd_start(struct watchdog_device *wdd) > +{ > + return smcwd_call(SMCWD_ENABLE, 1, NULL); > +} > + > +static const struct watchdog_info smcwd_info =3D { > + .identity =3D DRV_NAME, > + .options =3D WDIOF_SETTIMEOUT | > + WDIOF_KEEPALIVEPING | > + WDIOF_MAGICCLOSE, > +}; > + > +static const struct watchdog_ops smcwd_ops =3D { > + .owner =3D THIS_MODULE, > + .start =3D smcwd_start, > + .stop =3D smcwd_stop, > + .ping =3D smcwd_ping, > + .set_timeout =3D smcwd_set_timeout, > +}; > + > +static int smcwd_probe(struct platform_device *pdev) > +{ > + struct watchdog_device *wdd; > + int err; > + struct arm_smccc_res res; > + > + err =3D smcwd_call(SMCWD_INFO, 0, &res); > + if (err < 0) > + return err; > + > + wdd =3D devm_kzalloc(&pdev->dev, sizeof(*wdd), GFP_KERNEL); > + if (!wdd) > + return -ENOMEM; > + > + platform_set_drvdata(pdev, wdd); > + > + wdd->info =3D &smcwd_info; > + wdd->ops =3D &smcwd_ops; > + wdd->timeout =3D res.a2; > + wdd->max_timeout =3D res.a2; > + wdd->min_timeout =3D res.a1; > + wdd->parent =3D &pdev->dev; > + > + watchdog_set_nowayout(wdd, nowayout); > + watchdog_init_timeout(wdd, timeout, &pdev->dev); > + err =3D smcwd_set_timeout(wdd, wdd->timeout); > + if (err) > + return err; > + > + err =3D watchdog_register_device(wdd); > + if (err) > + return err; > + > + dev_info(&pdev->dev, "Watchdog enabled (timeout=3D%d sec, nowayou= t=3D%d)\n", > + wdd->timeout, nowayout); > + > + return 0; > +} > + > +static void smcwd_shutdown(struct platform_device *pdev) > +{ > + struct watchdog_device *wdd =3D platform_get_drvdata(pdev); > + > + if (watchdog_active(wdd)) > + smcwd_stop(wdd); > +} > + > +static int smcwd_remove(struct platform_device *pdev) > +{ > + struct watchdog_device *wdd =3D platform_get_drvdata(pdev); > + > + watchdog_unregister_device(wdd); > + > + return 0; > +} > + > +static const struct of_device_id smcwd_dt_ids[] =3D { > + { .compatible =3D "arm,smc-wdt" }, > + { /* sentinel */ } nit: not sure about this subsystem, but usually the /* sentinel */ word is removed because is really trivial what is { } at the end of struct. > +}; > +MODULE_DEVICE_TABLE(of, smcwd_dt_ids); > + > +static struct platform_driver smcwd_driver =3D { > + .probe =3D smcwd_probe, > + .remove =3D smcwd_remove, > + .shutdown =3D smcwd_shutdown, > + .driver =3D { > + .name =3D DRV_NAME, > + .of_match_table =3D smcwd_dt_ids, > + }, > +}; > + > +module_platform_driver(smcwd_driver); > + > +module_param(timeout, uint, 0); > +MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds"); > + > +module_param(nowayout, bool, 0); > +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (def= ault=3D" > + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); > + > +MODULE_LICENSE("GPL"); > +MODULE_AUTHOR("Julius Werner "); > +MODULE_DESCRIPTION("ARM Secure Monitor Call Watchdog Driver"); > +MODULE_VERSION(DRV_VERSION); > -- > 2.25.0.265.gbab2e86ba0-goog >