Received: by 2002:ac0:8c9a:0:0:0:0:0 with SMTP id r26csp522562ima; Fri, 1 Feb 2019 06:55:45 -0800 (PST) X-Google-Smtp-Source: ALg8bN6bidROTw+9UlZ3iTwLLUu/E9GXYBe/qucRl31EzI3ckkLx3ywWbA3JNInAHL14wuKAuE6P X-Received: by 2002:a17:902:848f:: with SMTP id c15mr32523922plo.119.1549032945256; Fri, 01 Feb 2019 06:55:45 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1549032945; cv=none; d=google.com; s=arc-20160816; b=KPung64MfJB0Bq1RjAUdZ/ZT83hR1ASNzSbPNmoGSIaPNeC8IwJuQ7nGIfNKZNFBEO /M2Q0nmlc5e4FtncENlMFaMwoLINvGiG4Al73ZXpoyFZnT44aTJ66B52gEf9YlDsSRDb MGRRu/nRq5kxjW16+R8auN/bOZJmvQZRobFnDbRen5CtVoadWgI/mU9Dkvlu3ewsspmv +68fZFCDopsW+s4I8c36+Z3t987TymouhtDktQsTx1Q53oaNqSPYJQDSjzitzF0sQRzf 0auccblbiBsssX8p2jOK06BBP/Ia2bZ0Kw1VLYcTV2AmiRO7tnWVZxv+2A0s+JG9Vjg3 RG2A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date; bh=+4xAWvOOfptiaOqK2pimhvmibgaiK5oZEhkUgabzbqg=; b=zrPtsVL2mF9Y6kmS4+mARSZ8izplT6Egn5RDSDGJXRoUMv+/uZL+6fYu3tNr3ghXJt TsVZ+OwzaWipHet2HeWekLOZKPNK/Zq2/6TF2guWXaaqs3ebLQYIQKY5V07Z0rC3Fzvf OvjnPNRoF5lxw0wU6JvPrZpW5dBXRVEEAl1p4qPH84DQAFQ9e7kepnEHCWQguzf1cd1b iOgUSKSRuafgz/wWV0cXzM9JsjgylpE+OrtcAI+/U4/DN+IGxXM31ecHILxEUXjL8G5r 89y06jEeAQ0KmVrbAXsyrvtf2iU/PxN2AEy5PFTbaomdYqKiEAVSC0knxDMFjskDJlPp dF9Q== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id q3si7127821plb.209.2019.02.01.06.55.30; Fri, 01 Feb 2019 06:55:45 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729779AbfBAOy5 (ORCPT + 99 others); Fri, 1 Feb 2019 09:54:57 -0500 Received: from mga05.intel.com ([192.55.52.43]:26928 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726446AbfBAOy4 (ORCPT ); Fri, 1 Feb 2019 09:54:56 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 01 Feb 2019 06:54:56 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,549,1539673200"; d="scan'208";a="123181295" Received: from unknown (HELO localhost.localdomain) ([10.232.112.69]) by orsmga003.jf.intel.com with ESMTP; 01 Feb 2019 06:54:55 -0800 Date: Fri, 1 Feb 2019 07:54:14 -0700 From: Keith Busch To: Takao Indoh Cc: axboe@fb.com, hch@lst.de, sagi@grimberg.me, linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, Takao Indoh Subject: Re: [PATCH] nvme: Enable acceleration feature of A64FX processor Message-ID: <20190201145414.GA22199@localhost.localdomain> References: <20190201124615.16107-1-indou.takao@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190201124615.16107-1-indou.takao@jp.fujitsu.com> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 01, 2019 at 09:46:15PM +0900, Takao Indoh wrote: > From: Takao Indoh > > Fujitsu A64FX processor has a feature to accelerate data transfer of > internal bus by relaxed ordering. It is enabled when the bit 56 of dma > address is set to 1. Wait, what? RO is a standard PCIe TLP attribute. Why would we need this?