From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-x241.google.com (mail-qk0-x241.google.com [IPv6:2607:f8b0:400d:c09::241]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3wtvdK2hXnzDqjH for ; Fri, 23 Jun 2017 07:20:53 +1000 (AEST) Received: by mail-qk0-x241.google.com with SMTP id 16so3901333qkg.2 for ; Thu, 22 Jun 2017 14:20:53 -0700 (PDT) Sender: Richard Henderson 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 MIME-Version: 1.0 In-Reply-To: <20170622164817.25515-5-logang@deltatee.com> Content-Type: text/plain; charset=utf-8; format=flowed List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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.