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 C735BC3DA4A for ; Thu, 22 Aug 2024 10:47:26 +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=130Bb7iGM4IiJnWyCyMIcJDc9FNtzAAmWkd6A+PuPag=; b=JICMhmpups+VRHQVPWVeCGvVXD KfoTcYIEXk9SOCXzJjy71ISzq0Z+NEGERLiHYJ4Jrv4DErtmmvikBm07NmTjBoxFAbxWymxcAmsfa Md2+i071awRD6jkXIuRhkQLBxv6G7+5Po0di3VUo2514WUiP4n+eaJkVOIn+gmrvqKKbNXi/cP7iS 5uhjE70Pdinqr+om+VeTHZKfHlqbjKEZFZJnOn0GYjxgK9tOaYP3RenroGhGirpfJ1wdieOvV22TI RG1yRNNg1UdAmbqsRNSAI6EXi1IAf0e01npcPvcPP/3fDEY3f+GXfnZ5K2h3IUBuZ8tfl3oHVOZpy GuF8JIWA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sh5LZ-0000000CTZi-2LLC; Thu, 22 Aug 2024 10:47:17 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sh5Ko-0000000CTPK-17yg for linux-arm-kernel@lists.infradead.org; Thu, 22 Aug 2024 10:46:32 +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 ED9C9DA7; Thu, 22 Aug 2024 03:46:52 -0700 (PDT) Received: from bogus (e107155-lin.cambridge.arm.com [10.1.198.42]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 14CDE3F66E; Thu, 22 Aug 2024 03:46:23 -0700 (PDT) Date: Thu, 22 Aug 2024 11:46:21 +0100 From: Sudeep Holla To: Florian Fainelli Cc: linux-arm-kernel@lists.infradead.org, Rob Herring , Krzysztof Kozlowski , Conor Dooley , Sudeep Holla , Cristian Marussi , devicetree@vger.kernel.org (open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS), linux-kernel@vger.kernel.org (open list), arm-scmi@vger.kernel.org (open list:SYSTEM CONTROL & POWER/MANAGEMENT INTERFACE), justin.chen@broadcom.com, opendmb@gmail.com, kapil.hali@broadcom.com, bcm-kernel-feedback-list@broadcom.com Subject: Re: [PATCH v3 2/2] firmware: arm_scmi: Support 'reg-io-width' property for shared memory Message-ID: References: <20240816224221.3256455-1-florian.fainelli@broadcom.com> <20240816224221.3256455-3-florian.fainelli@broadcom.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240816224221.3256455-3-florian.fainelli@broadcom.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240822_034630_406767_E91B52A9 X-CRM114-Status: GOOD ( 12.56 ) 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 Hi Florian, Sorry for getting late to this party, I wasn't able to review this before. Overall changes look correct. But my main concern is that is SCMI the right place to have such IO accessors. It is better to run it through Arnd if he is happy with it before I send him the pull request containing these. On Fri, Aug 16, 2024 at 03:42:21PM -0700, Florian Fainelli wrote: > Some shared memory areas might only support a certain access width, > such as 32-bit, which memcpy_{from,to}_io() does not adhere to at least > on ARM64 by making both 8-bit and 64-bit accesses to such memory. > Is this limitation on the hardware for both read and writes ? The reason I ask is I see arm64 does have memcpy_toio_aligned() or __iowrite32_copy_full() for 32 bit aligned writes. -- Regards, Sudeep