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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 74BFCC282D1 for ; Mon, 3 Mar 2025 14:49:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=3AaXglqBPlc/ouLZcp3hxFj9nawQ7T6NNeT4rwMrQgc=; b=RlX8RjJDGWW/QRaXVUUFiUt8Lm pM9/5W7P3KQMMpT4eSZEgE/X0lt4vrpfme3+PPujyqnR4Pxf+w7o2Jsn87WzzUNQmqslZOLSBGZUg sXuU+6zWtXuOXimMFG8SLKHn/Woc/Y+QZc4wsGaIWp/Piuzr7TYxOPyVREm82Ai9aNuwDj7+aw/3o 6vTiFQhk9RlngUB7KbdoS1QgMjEfV9A3AABnUGZ4R4JWZB28JSgB3JRhoSwFQuhakFZJ8Sb3vxltm rQEfLrNCsvq77MljKsmbmtigHctqSCcSxSBNH9Y/kTOZSoH+UwWFyaFBireB4rPCFV56nZ+vCbIRr 9bQo6nSQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tp76Z-00000001Ac2-12Mk; Mon, 03 Mar 2025 14:49:15 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tp72z-000000019uD-0jLP for linux-arm-kernel@lists.infradead.org; Mon, 03 Mar 2025 14:45:34 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 72BAD106F; Mon, 3 Mar 2025 06:45:46 -0800 (PST) Received: from bogus (e133711.arm.com [10.1.196.55]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 41B9D3F66E; Mon, 3 Mar 2025 06:45:31 -0800 (PST) Date: Mon, 3 Mar 2025 14:45:28 +0000 From: Sudeep Holla To: Paul Benoit , Mark Rutland Cc: , Sudeep Holla , Lorenzo Pieralisi , Subject: Re: [PATCH v4] firmware: smccc: Support optional Arm SMC SOC_ID name Message-ID: References: <20241114030452.10149-1-paul@os.amperecomputing.com> <20250219005932.3466-1-paul@os.amperecomputing.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250303_064533_301991_D27DF7FA X-CRM114-Status: GOOD ( 26.79 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Mar 03, 2025 at 02:18:05PM +0000, Mark Rutland wrote: > Hi Paul, > > This looks generally good with a couple of minor nits. > > On Tue, Feb 18, 2025 at 04:59:32PM -0800, Paul Benoit wrote: > > Issue Number 1.6 of the Arm SMC Calling Convention introduces an optional > > SOC_ID name string. If implemented, point the 'machine' field of the SoC > > Device Attributes at this string so that it will appear under > > /sys/bus/soc/devices/soc0/machine. > > > > On Arm SMC compliant SoCs, this will allow things like 'lscpu' to > > eventually get a SoC provider model name from there rather than each > > tool/utility needing to get a possibly inconsistent, obsolete, or incorrect > > model/machine name from its own hardcoded model/machine name table. > > > > Signed-off-by: Paul Benoit > > Cc: Mark Rutland > > Cc: Lorenzo Pieralisi > > Cc: Sudeep Holla > > Cc: linux-arm-kernel@lists.infradead.org > > --- [...] > > +static char __init *smccc_soc_name_init(void) > > +{ > > + struct arm_smccc_1_2_regs args; > > + struct arm_smccc_1_2_regs res; > > + size_t len; > > + > > + /* > > + * Issue Number 1.6 of the Arm SMC Calling Convention > > + * specification introduces an optional "name" string > > + * to the ARM_SMCCC_ARCH_SOC_ID function. Fetch it if > > + * available. > > + */ > > + args.a0 = ARM_SMCCC_ARCH_SOC_ID; > > + args.a1 = 2; /* SOC_ID name */ > > + arm_smccc_1_2_invoke(&args, &res); > > + if ((u32)res.a0 == 0) { > > + const unsigned int regsize = sizeof(res.a1); > > + > > + /* > > + * Copy res.a1..res.a17 to the smccc_soc_id_name string > > + * 8 bytes at a time. As per Issue 1.6 of the Arm SMC > > + * Calling Convention, the string will be NUL terminated > > + * and padded, from the end of the string to the end of the > > + * 136 byte buffer, with NULs. > > + */ > > + str_fragment_from_reg(smccc_soc_id_name + 0*regsize, res.a1); > > + str_fragment_from_reg(smccc_soc_id_name + 1*regsize, res.a2); > > + str_fragment_from_reg(smccc_soc_id_name + 2*regsize, res.a3); > > + str_fragment_from_reg(smccc_soc_id_name + 3*regsize, res.a4); > > + str_fragment_from_reg(smccc_soc_id_name + 4*regsize, res.a5); > > + str_fragment_from_reg(smccc_soc_id_name + 5*regsize, res.a6); > > + str_fragment_from_reg(smccc_soc_id_name + 6*regsize, res.a7); > > + str_fragment_from_reg(smccc_soc_id_name + 7*regsize, res.a8); > > + str_fragment_from_reg(smccc_soc_id_name + 8*regsize, res.a9); > > + str_fragment_from_reg(smccc_soc_id_name + 9*regsize, res.a10); > > + str_fragment_from_reg(smccc_soc_id_name + 10*regsize, res.a11); > > + str_fragment_from_reg(smccc_soc_id_name + 11*regsize, res.a12); > > + str_fragment_from_reg(smccc_soc_id_name + 12*regsize, res.a13); > > + str_fragment_from_reg(smccc_soc_id_name + 13*regsize, res.a14); > > + str_fragment_from_reg(smccc_soc_id_name + 14*regsize, res.a15); > > + str_fragment_from_reg(smccc_soc_id_name + 15*regsize, res.a16); > > + str_fragment_from_reg(smccc_soc_id_name + 16*regsize, res.a17); > > Please get rid of 'regsize' and use '8' directly. This only exists for > arm64, where the registeres are 8 bytes, and the comment immediately > above refers to "8 bytes" specifically anyway, so 'regsize' only serves > to make this harder to read. > > It'd be a bit clearer as: > > str_fragment_from_reg(smccc_soc_id_name + 8 * 0, res.a1); > str_fragment_from_reg(smccc_soc_id_name + 8 * 1, res.a2); > ... > str_fragment_from_reg(smccc_soc_id_name + 8 * 15, res.a16); > str_fragment_from_reg(smccc_soc_id_name + 8 * 16, res.a17); > > Sudeep, are you happy to fix that up when applying? > > > + > > + len = strnlen(smccc_soc_id_name, sizeof(smccc_soc_id_name)); > > + if (len) { > > + if (len == sizeof(smccc_soc_id_name)) > > + pr_warn(FW_BUG "Ignoring improperly formatted Name\n"); > > It's odd that 'Name' is capitalized here. Not a big deal, but it doesn't > look quite right. > I can fix both of these and apply. No need to repost. -- Regards, Sudeep