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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,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 838A6C169C4 for ; Mon, 11 Feb 2019 20:35:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 52633218D8 for ; Mon, 11 Feb 2019 20:35:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549917318; bh=3jDQwnRz/p/blpP5NJhVM/v/GNO91OWCupemhUCpwaE=; h=From:Subject:To:Cc:References:Date:In-Reply-To:List-ID:From; b=nQeZHkziNoa7VESTCixzuqZAHywLz1J4rrH7qG5kQdT9g4VrG3iWH7lFssfV1L2Ez r4qKWvSW46oO8479l1NjJ954V7QZoYBNm26MPoE1F8TTBuHqgQvH6/qK45lY6kI3Dc dN0P25WawioDatIQt6Re5entudkIneS4UVHcESQE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727451AbfBKUfQ (ORCPT ); Mon, 11 Feb 2019 15:35:16 -0500 Received: from mail-qk1-f194.google.com ([209.85.222.194]:41281 "EHLO mail-qk1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726207AbfBKUfP (ORCPT ); Mon, 11 Feb 2019 15:35:15 -0500 Received: by mail-qk1-f194.google.com with SMTP id u188so7305022qkh.8; Mon, 11 Feb 2019 12:35:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:subject:to:cc:references:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=NzkMLHlmh/2mUIvkidKlXjIkFy1c+76A+Xd7Q1175rQ=; b=GZ5IliSVxhFVU0qk3/hSzopZlizwQa2O5Q2KY80oIgUVAoaEz2G8tR9gdJZPsTkfZ/ nLRXZv4kGrI6vgzzz1+0w9RJg+6c4RHWjrA+hlzX++WVII3sDEsaBkZLjkcYvXoSbdKa PkcwakhJZvkCQXejUOSih5f7ZCLlOX70QXqNaSfD/SlahamxT7WUM8Us9GbBdVQVujH+ 6+ZDWn4jEfHTHtWkI5xH/vnCngsl923sNn+yB0StJYNs0+6pfdYTcvM9JiEvNmeg/YZc 1b9ydd0DPJqvG98xbPDbgxMCw+7nnyylYufPbWvguM4PRq5k2Or56wZYBvzd4hpZY0sB rBFQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:subject:to:cc:references:message-id :date:user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=NzkMLHlmh/2mUIvkidKlXjIkFy1c+76A+Xd7Q1175rQ=; b=aHSZw+xk8P1H0AY6VG5Io2CFgozdRHF8vt0ypcERWQf/APeQxqnnLwOeKVZB0QS1N+ b5F2MLO4xXZIKRdOEZ1Mq+L2QuWyBM/sflDxOcNQiHBOMcDCiZ+WAyIqZzc3nPaFv49n ZFmP3Wqj1USJ4Bzh+izC6E1LfdSYzlxNZnjKazHsnp7nbc7B8XTdqIGTlEfLFs79Ecst 5lHHsZksSiJpWOMOHm86Dv6+KwWAr+h1FCovLV6XixLkEytbu/jSJYHRGGluinwmfgxD YgSg2+WpGiDA08amz9fWtv2kb8ZERktVUN0XMLJOPOF6PUiecDCBhSWQKPfnjY+xDCgD Z38A== X-Gm-Message-State: AHQUAuY5sDbGvZuyK9/EA6F1QxRr+Cq8zewjhcHPH1pu8z7uLDc0LyFg /l1KElRjT1Vy5ReRcm60hEA= X-Google-Smtp-Source: AHgI3IYcSQ64HD+iqxa0zU9DfKmDSQRTaZBHwxxwh/f4es0sNeCrO5e9bbXXAxWHY+fz43/e/BxANA== X-Received: by 2002:a37:c30d:: with SMTP id a13mr90085qkj.18.1549917314552; Mon, 11 Feb 2019 12:35:14 -0800 (PST) Received: from ?IPv6:2001:4898:4070:71:3025:7b73:eee8:a16e? ([2001:4898:8010:1:f0f4:7b73:eee8:a16e]) by smtp.gmail.com with ESMTPSA id f3sm10861727qkj.24.2019.02.11.12.35.13 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Feb 2019 12:35:13 -0800 (PST) From: Sinan Kaya X-Google-Original-From: Sinan Kaya Subject: Re: [PATCH v1 1/2] PCI: ATS: Add function to check ATS page aligned request status. To: "Raj, Ashok" Cc: sathyanarayanan.kuppuswamy@linux.intel.com, bhelgaas@google.com, joro@8bytes.org, dwmw2@infradead.org, linux-pci@vger.kernel.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Jacob Pan , Keith Busch References: <91bfae8b1d4b424219e3ce3c1fc03559c73f1ae7.1549478584.git.sathyanarayanan.kuppuswamy@linux.intel.com> <5d55e369-355f-b710-0594-03465aa985da@kernel.org> <32ec3293-28ea-8f0f-f801-0370b4cf0453@kernel.org> <351a1a1d-2517-5021-e7cd-99d700e17f4c@linux.intel.com> <815f2621-fc28-bff4-c300-cce7514cfe71@kernel.org> <20190211191549.GA12090@otc-nc-03> Message-ID: Date: Mon, 11 Feb 2019 15:35:13 -0500 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.5.0 MIME-Version: 1.0 In-Reply-To: <20190211191549.GA12090@otc-nc-03> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/11/2019 2:15 PM, Raj, Ashok wrote: > It seems rather odd we have to check for ATS version. > > I always assumed unspecified bits (Reserved) must be 0. We only check > this if ATS is enabled, and this particular bit wasn't given away for another > feature. > > Is it really required to check for ATS version before consuming this? Reading again, it looks like version check is not necessary since it is implied by the presence of this bit per this paragraph. Page Aligned Request – If Set, indicates the Untranslated Address is always aligned to a 4096 byte boundary. Setting this bit is recommended. This bit permits software to distinguish between implementations compatible with earlier version of this specification that permitted a requester to supply anything in bits [11:2].