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=-6.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 94A31C433E0 for ; Thu, 11 Mar 2021 16:49:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5CBC364FF6 for ; Thu, 11 Mar 2021 16:49:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229854AbhCKQss (ORCPT ); Thu, 11 Mar 2021 11:48:48 -0500 Received: from mail.kernel.org ([198.145.29.99]:59662 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229632AbhCKQs0 (ORCPT ); Thu, 11 Mar 2021 11:48:26 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5ED2864FFB; Thu, 11 Mar 2021 16:48:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1615481305; bh=FgHbw5HS/VjP7/VZBF5aykDpmElBQPo7RYwq/98R/y0=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=Xjm2VLWQbRLzLjMb3wGyLY/D8Qc6zsY+gHm5tR9VhAap9AW7Ethi7WR+IkUl/0Ven 86SK1RQXK0WdIlpmesgdJltCy4fWuo7zvsnG84lBdRk/0N5nLcpvF/hUG2KEB5pLoz tWo9qSkUf4/NaR5c1K87+wc/ZFqufD/AI9+3vQKwbJ0F6MTGOe0EjpzFbfmJFgp1By 6it0kiNaV/p+q+R5Epwa6oFu3B96Y6qWUqC8c+bS1k1kY7FIeO2gDXVNEjQ/8GKwYd rhLOSyDPImswIt6JrFSqzVhWrt1RA+zyTvkjXNeUBHAjiZOmku848V1UN6kGJtsqcW bxfRyUcYFwIww== Received: by mail-oo1-f46.google.com with SMTP id e19-20020a4a73530000b02901b62c0e1bb6so831805oof.11; Thu, 11 Mar 2021 08:48:25 -0800 (PST) X-Gm-Message-State: AOAM532BIdwPeQXtk+8rcA4oFQkV2ikl5155G19Ek+co8I95IqiPvwaY og6VIqYmRUq73oCM8eEBS4Qx5qLkT3pj6c58zYw= X-Google-Smtp-Source: ABdhPJwIgrbXVP3PRPUXHopliI3qsXWZiXkZVPwqkBfIWll0HvAMT6p5npMnLVv5OxG3dnsn4P6GmJ7wCO0i3CmSEgk= X-Received: by 2002:a4a:304a:: with SMTP id z10mr7486554ooz.26.1615481304355; Thu, 11 Mar 2021 08:48:24 -0800 (PST) MIME-Version: 1.0 References: <20210304213902.83903-1-marcan@marcan.st> <20210304213902.83903-13-marcan@marcan.st> <6e4880b3-1fb6-0cbf-c1a5-7a46fd9ccf62@marcan.st> <20210308211306.GA2920998@robh.at.kernel.org> <332c0b9a-dcfd-4c3b-9038-47cbda90eb3f@marcan.st> In-Reply-To: From: Arnd Bergmann Date: Thu, 11 Mar 2021 17:48:07 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [RFT PATCH v3 12/27] of/address: Add infrastructure to declare MMIO as non-posted To: Rob Herring Cc: Hector Martin , linux-arm-kernel , Marc Zyngier , Olof Johansson , Krzysztof Kozlowski , Mark Kettenis , Tony Lindgren , Mohamed Mediouni , Stan Skowronek , Alexander Graf , Will Deacon , Linus Walleij , Mark Rutland , Andy Shevchenko , Greg Kroah-Hartman , Jonathan Corbet , Catalin Marinas , Christoph Hellwig , "David S. Miller" , DTML , "open list:SERIAL DRIVERS" , Linux Doc Mailing List , linux-samsung-soc , "open list:GENERIC INCLUDE/ASM HEADER FILES" , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 11, 2021 at 5:10 PM Rob Herring wrote: > On Thu, Mar 11, 2021 at 2:12 AM Arnd Bergmann wrote: > > On Wed, Mar 10, 2021 at 6:01 PM Rob Herring wrote: > > Ok, makes sense. > > > > Conceptually, I'd like to then see a check that verifies that the > > property is only set for nodes whose parent also has it set, since > > that is how AXI defines it: A bus can wait for the ack from its > > child node, or it can acknowledge the write to its parent early. > > However, this breaks down as soon as a bus does the early ack: > > all its children by definition use posted writes (as seen by the > > CPU), even if they wait for stores that come from other masters. > > > > Does this make sense to you? > > BTW, I don't think it's clear in this thread, but the current > definition proposed for the spec[1] and schema is 'nonposted-mmio' is > specific to 'simple-bus'. I like this restriction and we can expand > where 'nonposted-mmio' is allowed later if needed. That sounds ok, as long as we can express everything for the mac at the moment. Do we need to explicitly add a description to allow the property in the root node in addition to simple-bus to be able to enforce the rule about parent buses also having it? Arnd 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=-4.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 4470CC4321A for ; Thu, 11 Mar 2021 16:49:53 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 99EAA64FF1 for ; Thu, 11 Mar 2021 16:49:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 99EAA64FF1 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+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=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:Cc:To:Subject:Message-ID:Date:From:In-Reply-To: References:MIME-Version:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=kuK8a92o8UkZ6zYCtTjywkYVcf/yBiItDWG5B6yxJrs=; b=fRnsM9sgmoUYWALvQBzsyyoG4 KSnuTmWnGmCWm0/KcxeMHgfveQ4V9jvtzOYQ7eAsmiPMvEmdithS9O5dbvxcc+uFoe0jATg3knJOZ rBOi/sIzlpW9QsL/upPL0nMx53nYc3xKmr5yexMpj1dGJXCwQA6m7VP7Gan3tK/kgey3+5JhlUCKY OvqcRkUGXVPJzx8aYeExeKd4HulEypaH4w/Cvr4+NmjNnrTFzK/3UPJ8fuhWydzxzrfVyCITzaHh/ dXA7IXs/iDBP1WM06JCksLhCcvD9NziMpzZf/QvHMHVFvpLCVPDfhK1Fikf1w3CY+3a/pNLOgkzVt cYiePwPEg==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lKOUC-009c7N-PW; Thu, 11 Mar 2021 16:48:32 +0000 Received: from mail.kernel.org ([198.145.29.99]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lKOU6-009c5U-TS for linux-arm-kernel@lists.infradead.org; Thu, 11 Mar 2021 16:48:30 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 53FE564FF5 for ; Thu, 11 Mar 2021 16:48:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1615481305; bh=FgHbw5HS/VjP7/VZBF5aykDpmElBQPo7RYwq/98R/y0=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=Xjm2VLWQbRLzLjMb3wGyLY/D8Qc6zsY+gHm5tR9VhAap9AW7Ethi7WR+IkUl/0Ven 86SK1RQXK0WdIlpmesgdJltCy4fWuo7zvsnG84lBdRk/0N5nLcpvF/hUG2KEB5pLoz tWo9qSkUf4/NaR5c1K87+wc/ZFqufD/AI9+3vQKwbJ0F6MTGOe0EjpzFbfmJFgp1By 6it0kiNaV/p+q+R5Epwa6oFu3B96Y6qWUqC8c+bS1k1kY7FIeO2gDXVNEjQ/8GKwYd rhLOSyDPImswIt6JrFSqzVhWrt1RA+zyTvkjXNeUBHAjiZOmku848V1UN6kGJtsqcW bxfRyUcYFwIww== Received: by mail-oo1-f41.google.com with SMTP id h3-20020a4ae8c30000b02901b68b39e2d3so830414ooe.9 for ; Thu, 11 Mar 2021 08:48:25 -0800 (PST) X-Gm-Message-State: AOAM533Q5TE5aFx++0EJVxAsbC7bEh57rf8IyEhElZpTtVvQ7iDNAfSf W8Lx+pDUMPsWUHf9KpJJTfeE3iw2zksdEEX9Z/o= X-Google-Smtp-Source: ABdhPJwIgrbXVP3PRPUXHopliI3qsXWZiXkZVPwqkBfIWll0HvAMT6p5npMnLVv5OxG3dnsn4P6GmJ7wCO0i3CmSEgk= X-Received: by 2002:a4a:304a:: with SMTP id z10mr7486554ooz.26.1615481304355; Thu, 11 Mar 2021 08:48:24 -0800 (PST) MIME-Version: 1.0 References: <20210304213902.83903-1-marcan@marcan.st> <20210304213902.83903-13-marcan@marcan.st> <6e4880b3-1fb6-0cbf-c1a5-7a46fd9ccf62@marcan.st> <20210308211306.GA2920998@robh.at.kernel.org> <332c0b9a-dcfd-4c3b-9038-47cbda90eb3f@marcan.st> In-Reply-To: From: Arnd Bergmann Date: Thu, 11 Mar 2021 17:48:07 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [RFT PATCH v3 12/27] of/address: Add infrastructure to declare MMIO as non-posted To: Rob Herring Cc: Hector Martin , linux-arm-kernel , Marc Zyngier , Olof Johansson , Krzysztof Kozlowski , Mark Kettenis , Tony Lindgren , Mohamed Mediouni , Stan Skowronek , Alexander Graf , Will Deacon , Linus Walleij , Mark Rutland , Andy Shevchenko , Greg Kroah-Hartman , Jonathan Corbet , Catalin Marinas , Christoph Hellwig , "David S. Miller" , DTML , "open list:SERIAL DRIVERS" , Linux Doc Mailing List , linux-samsung-soc , "open list:GENERIC INCLUDE/ASM HEADER FILES" , "linux-kernel@vger.kernel.org" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210311_164827_340730_7F64DB76 X-CRM114-Status: GOOD ( 23.53 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Mar 11, 2021 at 5:10 PM Rob Herring wrote: > On Thu, Mar 11, 2021 at 2:12 AM Arnd Bergmann wrote: > > On Wed, Mar 10, 2021 at 6:01 PM Rob Herring wrote: > > Ok, makes sense. > > > > Conceptually, I'd like to then see a check that verifies that the > > property is only set for nodes whose parent also has it set, since > > that is how AXI defines it: A bus can wait for the ack from its > > child node, or it can acknowledge the write to its parent early. > > However, this breaks down as soon as a bus does the early ack: > > all its children by definition use posted writes (as seen by the > > CPU), even if they wait for stores that come from other masters. > > > > Does this make sense to you? > > BTW, I don't think it's clear in this thread, but the current > definition proposed for the spec[1] and schema is 'nonposted-mmio' is > specific to 'simple-bus'. I like this restriction and we can expand > where 'nonposted-mmio' is allowed later if needed. That sounds ok, as long as we can express everything for the mac at the moment. Do we need to explicitly add a description to allow the property in the root node in addition to simple-bus to be able to enforce the rule about parent buses also having it? Arnd _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel