From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755515Ab1JMPdM (ORCPT ); Thu, 13 Oct 2011 11:33:12 -0400 Received: from gate.crashing.org ([63.228.1.57]:45848 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752464Ab1JMPdK convert rfc822-to-8bit (ORCPT ); Thu, 13 Oct 2011 11:33:10 -0400 Subject: Re: [PATCH][v2] uio: Support 36-bit physical addresses on 32-bit systems Mime-Version: 1.0 (Apple Message framework v1251.1) Content-Type: text/plain; charset=US-ASCII From: Kumar Gala In-Reply-To: Date: Thu, 13 Oct 2011 10:32:51 -0500 Cc: "hjk@hansjkoch.de" , "linuxppc-dev@ozlabs.org" , "gregkh@suse.de" , Jiang Kai-B18973 , "linux-kernel@vger.kernel.org" Content-Transfer-Encoding: 7BIT Message-Id: <9BD33578-CD8E-4784-AC6A-ADE4614E0FC1@kernel.crashing.org> References: <1318453063-17349-1-git-send-email-galak@kernel.crashing.org> To: Tabi Timur-B04825 X-Mailer: Apple Mail (2.1251.1) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Oct 13, 2011, at 9:37 AM, Tabi Timur-B04825 wrote: > On Wed, Oct 12, 2011 at 3:57 PM, Kumar Gala wrote: >> From: Kai Jiang >> >> To support >32-bit physical addresses for UIO_MEM_PHYS type we need to >> extend the width of 'addr' in struct uio_mem. Numerous platforms like >> embedded PPC, ARM, and X86 have support for systems with larger physical >> address than logical. >> >> Since 'addr' may contain a physical, logical, or virtual address the >> easiest solution is to just change the type to 'unsigned long long' >> regardless of which type is utilized. > > You forgot to update this description. will fix and update commit message > >> struct uio_mem { >> const char *name; >> - unsigned long addr; >> + phys_addr_t addr; > > Please add a comment here saying: > > 1) That 'addr' can be a virtual or physical address The code and everything else makes that clear > 2) That the kernel guarantees that sizeof(phys_addr_t) >= sizeof(void > *), so it's safe to use phys_addr_t for a virtual pointer. The commit message will cover that so I don't plan on add it. - k