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=-2.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT 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 A17C6C10F0E for ; Fri, 12 Apr 2019 09:55:47 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7285D20850 for ; Fri, 12 Apr 2019 09:55:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="HB8Rbgwd" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7285D20850 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=+poGBz61lW2spfyzv2IGmNrOST5MAAUEuycY8/SeGns=; b=HB8Rbgwd00HRrQ Wts0o9H3VYO1Iez5NiMydJVf1Kq7oHrS4WxkBqUFPI7cMEaaCzun539KyL/uSRXbZeXZcF4g0FnTl 2mO9Zb6FsFXhkyTYCTgPMqOvg3lRX1ssExQc7aYMTonNuC/3Ett9x4MqEAVNt5+YFV74kZFMe5eo+ VzNDf4uaenWqkqXS9YeuAf8o9L/Gsi6O3NuTVEmWfnHvaEIiGRPGjZ+HTx0yibBaSxZBttUsAmjx5 82+c3qrni2skaMJdc6EGhhekyCbuFW9lHlovWsnQ1CfI439NdfhA5+NLr+Joy+vrCbm+7NG9DF3CC xCFLEO9I/cCxXdeslCcA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hEsuL-0005XM-Lo; Fri, 12 Apr 2019 09:55:41 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hEsuI-0005X0-Oj for linux-arm-kernel@lists.infradead.org; Fri, 12 Apr 2019 09:55:40 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 45D0F15AB; Fri, 12 Apr 2019 02:55:38 -0700 (PDT) Received: from e107155-lin (e107155-lin.cambridge.arm.com [10.1.196.42]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id BDE343F59C; Fri, 12 Apr 2019 02:55:36 -0700 (PDT) Date: Fri, 12 Apr 2019 10:55:28 +0100 From: Sudeep Holla To: Aaro Koskinen Subject: Re: [RESEND][PATCH v2] firmware/psci: add support for SYSTEM_RESET2 Message-ID: <20190412095528.GA12424@e107155-lin> References: <20190411103346.22462-1-sudeep.holla@arm.com> <20190411164936.GB5327@e107155-lin> <20190411182637.GC16745@darkstar.musicnaut.iki.fi> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190411182637.GC16745@darkstar.musicnaut.iki.fi> User-Agent: Mutt/1.9.4 (2018-02-28) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190412_025538_812550_C32CA848 X-CRM114-Status: GOOD ( 22.82 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Florian Fainelli , Michal Simek , "linux-kernel@vger.kernel.org" , Lorenzo Pieralisi , "Koskinen, Aaro \(Nokia - FI/Espoo\)" , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Apr 11, 2019 at 09:26:37PM +0300, Aaro Koskinen wrote: > Hi, > > On Thu, Apr 11, 2019 at 05:49:36PM +0100, Sudeep Holla wrote: > > On Thu, Apr 11, 2019 at 11:42:28AM +0000, Koskinen, Aaro (Nokia - FI/Espoo) wrote: > > > From: Sudeep Holla [sudeep.holla@arm.com]: > > > > static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd) > > > > { > > > > + if ((reboot_mode == REBOOT_WARM || reboot_mode == REBOOT_SOFT) && > > > > > > I would omit the REBOOT_SOFT here. > > > > I included REBOOT_SOFT for 2 reasons: > > 1. drivers/firmware/efi/reboot.c - efi_reboot treats WARM and SOFT reboots same > > 2. If the vendors specific reboots are added and handled in EFI, I assume it > > will be categorised under REBOOT_SOFT. > > > > If that's wrong I can drop REBOOT_SOFT. > > Not a big issue, but it's just unclear what SOFT means. WARM at least maps > nicely to the PSCI spec. > OK, I will keep it for now. > > > > + psci_system_reset2_supported) > > > > + /* > > > > + * reset_type[31] = 0 (architectural) > > > > + * reset_type[30:0] = 0 (SYSTEM_WARM_RESET) > > > > + * cookie = 0 (ignored by the implementation) > > > > + */ > > > > + invoke_psci_fn(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2), 0, 0, 0); > > > > + > > > > invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0); > > > > > > Use else here, so that we fall back to system halt if SYSTEM_RESET2 fails. > > > > Will that not change current behaviour ? IOW, is that expected behaviour ? > > I am not sure if halt can be prefer over cold reboot in absence of warm/soft > > reboot when the system is request to reboot. From PSCI perspective, since > > SYSTEM_RESET is mandatory I prefer that unless Linux has any restriction > > on this behaviour. > > Hmm, so does it mean that even if firmware tells that SYSTEM_RESET2 > is implemented it does not imply that SYSTEM_WARM_RESET is > available? I.e. the firmware could choose to implement only some > vendor-specific resets but not architectural ones. In that case, could > we fall back to cold reset only if NOT_SUPPORTED is returned? My point > is that if the warm reset fails unexpectedly, we should halt the system > like we do if the cold reset fails. > OK, I understood. Sorry I was under the assumption that architectural reset was mandatory if SYSTEM_RESET2 is implemented. I checked the PSCI specification and I am wrong. So I am happy to add else as per your suggestion. -- Regards, Sudeep _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel