Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759808AbXLQMlt (ORCPT ); Mon, 17 Dec 2007 07:41:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754225AbXLQMll (ORCPT ); Mon, 17 Dec 2007 07:41:41 -0500 Received: from colin.muc.de ([193.149.48.1]:1273 "EHLO mail.muc.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753091AbXLQMll (ORCPT ); Mon, 17 Dec 2007 07:41:41 -0500 Date: 17 Dec 2007 13:41:37 +0100 Date: Mon, 17 Dec 2007 13:41:37 +0100 From: Andi Kleen To: Paul Mackerras Cc: Greg KH , David Miller , venkatesh.pallipadi@intel.com, ebiederm@xmission.com, rdreier@cisco.com, torvalds@linux-foundation.org, airlied@skynet.ie, davej@redhat.com, mingo@elte.hu, tglx@linutronix.de, hpa@zytor.com, akpm@linux-foundation.org, arjan@infradead.org, jesse.barnes@intel.com, linux-kernel@vger.kernel.org, suresh.b.siddha@intel.com Subject: Re: [RFC PATCH 08/12] PAT 64b: coherent mmap and sysfs bin ioctl Message-ID: <20071217124137.GA18648@muc.de> References: <20071213235543.568682000@intel.com> <20071213235712.813201000@intel.com> <20071214001932.GA10389@suse.de> <20071213.163505.14070110.davem@davemloft.net> <20071214063424.GB10100@suse.de> <18277.40798.828760.919571@cargo.ozlabs.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <18277.40798.828760.919571@cargo.ozlabs.ibm.com> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1088 Lines: 29 On Mon, Dec 17, 2007 at 08:57:50AM +1100, Paul Mackerras wrote: > Greg KH writes: > > > Ok, sorry, it wasn't blindingly obvious that this was for pci sysfs > > devices that are mmaped, that makes a bit more sense. > > > > But I'd like to see what ioctl is wanted here first. > > I believe the ioctl would be to set whether the mapping goes to I/O or > memory space, x86 cannot really access IO space through mmap so no that wasn't planned The main planned use was to get the translated bus address (after IOMMU) for a mapping and to set the caching modes. > So the alternative to the ioctl would be to have multiple files in > sysfs, one per combination of modes -- i.e., 4 files, or 3 if we > exclude the "I/O with write combining" mode, which would be > reasonable. At least for the IOMMU translation case that wouldn't work. -Andi -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/