Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752549AbWAFU1o (ORCPT ); Fri, 6 Jan 2006 15:27:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752546AbWAFU1O (ORCPT ); Fri, 6 Jan 2006 15:27:14 -0500 Received: from mx.pathscale.com ([64.160.42.68]:57991 "EHLO mx.pathscale.com") by vger.kernel.org with ESMTP id S1752548AbWAFU1F (ORCPT ); Fri, 6 Jan 2006 15:27:05 -0500 Content-Type: multipart/mixed; boundary="===============0495824558==" MIME-Version: 1.0 Subject: [PATCH 0 of 3] 32-bit MMIO copy routine Message-Id: Date: Fri, 6 Jan 2006 12:26:33 -0800 From: "Bryan O'Sullivan" To: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1318 Lines: 31 --===============0495824558== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Following some discussion with Roland, and patterned after the style anointed by Linus last week, here is a new version of the 32-bit MMIO copy routine needed by our InfiniPath device. The name of the routine has changed from memcpy_toio32 to __raw_memcpy_toio32. This reflects the basic nature of the routine; it dodes not guarantee the order in which writes are performed, nor does it perform a memory barrier after it is done. The reason for this is that our chip treats the first and last writes to some MMIO regions specially; our driver performs those directly using writel, and uses __raw_memcpy_toio32 for the bits in between. Regarding the specialised x86_64 implementation, Andi Kleen asked me to perform some measurements of its performance impact. It makes a difference of about 5% in performance on moderately large copies over the HyperTransport bus, compared to the generic implementation.