Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753703AbdFVVUy (ORCPT ); Thu, 22 Jun 2017 17:20:54 -0400 Received: from mail-qk0-f196.google.com ([209.85.220.196]:34649 "EHLO mail-qk0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752128AbdFVVUw (ORCPT ); Thu, 22 Jun 2017 17:20:52 -0400 Subject: Re: [PATCH 4/7] alpha: provide ioread64 and iowrite64 implementations To: Logan Gunthorpe , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-ntb@googlegroups.com, linux-alpha@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-crypto@vger.kernel.org, dri-devel@lists.freedesktop.org Cc: Arnd Bergmann , Greg Kroah-Hartman , Stephen Bates , Ivan Kokshaysky , Matt Turner References: <20170622164817.25515-1-logang@deltatee.com> <20170622164817.25515-5-logang@deltatee.com> From: Richard Henderson Message-ID: Date: Thu, 22 Jun 2017 14:20:43 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.1.0 MIME-Version: 1.0 In-Reply-To: <20170622164817.25515-5-logang@deltatee.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 682 Lines: 19 On 06/22/2017 09:48 AM, Logan Gunthorpe wrote: > Alpha implements its own io operation and doesn't use the > common library. Thus to make ioread64 and iowrite64 globally > available we need to add implementations for alpha. > > For this, we simply use calls that chain two 32-bit operations. > (mostly because I don't really understand the alpha architecture.) It's not difficult to provide this interface[*]. I believe the only reason I didn't do so from the beginning is that it wasn't used. r~ * At least for systems other than Jensen, which cannot generate 64-bit I/O. On the other hand, Jensen doesn't have PCI (EISA only), and so won't have any devices that care.