Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752476AbcJKTpS (ORCPT ); Tue, 11 Oct 2016 15:45:18 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:39953 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751981AbcJKTpR (ORCPT ); Tue, 11 Oct 2016 15:45:17 -0400 Subject: Re: [RFC PATCH 6/6] sparc64: Enable 64-bit DMA To: Christoph Hellwig References: <1475796816-14448-1-git-send-email-tushar.n.dave@oracle.com> <1475796816-14448-7-git-send-email-tushar.n.dave@oracle.com> <20161007073252.GA8290@infradead.org> <4a70e648-a854-55d1-54ac-313b84841d04@oracle.com> <20161011163806.GA21231@infradead.org> Cc: davem@davemloft.net, chris.hyser@oracle.com, sowmini.varadhan@oracle.com, vgupta@synopsys.com, robin.murphy@arm.com, jroedel@suse.de, egtvedt@samfundet.no, krzk@kernel.org, sparclinux@vger.kernel.org, linux-kernel@vger.kernel.org From: tndave Message-ID: Date: Tue, 11 Oct 2016 12:42:06 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 In-Reply-To: <20161011163806.GA21231@infradead.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Source-IP: userv0022.oracle.com [156.151.31.74] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 598 Lines: 18 On 10/11/2016 09:38 AM, Christoph Hellwig wrote: > Hi Tushar, > > On Fri, Oct 07, 2016 at 01:09:15AM -0700, tndave wrote: >> With change made by patch 6/6, dma_addr_t is always 64-bit, no matter if >> device DMA mask is 32-bit (i.e. using existing IOMMU) or 64-bit (i.e >> using ATU) > > But only iff CONFIG_ARCH_ATU is set. Anyway, I'll wait for your patches > to got in first and will then propose getting rid of > CONFIG_ARCH_DMA_ADDR_T_64BIT separately. CONFIG_ARCH_ATU is by default set on 'SPARC64'. Therefore CONFIG_ARCH_DMA_ADDR_T_64BIT is also always set as well on SPARC64. -Tushar >