Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261648AbUCVDFi (ORCPT ); Sun, 21 Mar 2004 22:05:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261651AbUCVDFi (ORCPT ); Sun, 21 Mar 2004 22:05:38 -0500 Received: from fw.osdl.org ([65.172.181.6]:1411 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S261648AbUCVDFd (ORCPT ); Sun, 21 Mar 2004 22:05:33 -0500 Date: Sun, 21 Mar 2004 19:05:24 -0800 (PST) From: Linus Torvalds To: Andrea Arcangeli cc: Jeff Garzik , David Woodhouse , Christoph Hellwig , William Lee Irwin III , Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: can device drivers return non-ram via vm_ops->nopage? In-Reply-To: <20040322003429.GE3649@dualathlon.random> Message-ID: References: <20040321204931.A11519@infradead.org> <1079902670.17681.324.camel@imladris.demon.co.uk> <20040321222327.D26708@flint.arm.linux.org.uk> <405E1859.5030906@pobox.com> <20040321225117.F26708@flint.arm.linux.org.uk> <405E23A5.7080903@pobox.com> <20040321235854.H26708@flint.arm.linux.org.uk> <20040322003429.GE3649@dualathlon.random> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1086 Lines: 30 On Mon, 22 Mar 2004, Andrea Arcangeli wrote: > > On Sun, Mar 21, 2004 at 11:58:54PM +0000, Russell King wrote: > > On Sun, Mar 21, 2004 at 03:51:31PM -0800, Linus Torvalds wrote: > > > That might be the minimal fix, since it would basically involve: > > > - change whatever offensive "virt_to_page()" calls into > > > "dma_map_to_page()". > > > - implement "dma_map_to_page()" for all architectures. > > > > > > Would that make people happy? > > > > Unfortunately this doesn't make dwmw2 happy - he claims to have machines > > which implement dma_alloc_coherent using RAM which doesn't have any > > struct page associated with it. > > I would suggest to add a ->nopage_dma (or whatever other name for an > additional callback in the vm_ops) that will return a non pageable "pfn" No. Fix the broken architecture instead. Linus - 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/