Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262006AbUFVKll (ORCPT ); Tue, 22 Jun 2004 06:41:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262045AbUFVKll (ORCPT ); Tue, 22 Jun 2004 06:41:41 -0400 Received: from cantor.suse.de ([195.135.220.2]:17537 "EHLO Cantor.suse.de") by vger.kernel.org with ESMTP id S262006AbUFVKlj (ORCPT ); Tue, 22 Jun 2004 06:41:39 -0400 Date: Tue, 22 Jun 2004 12:40:45 +0200 Message-ID: From: Takashi Iwai To: Linus Torvalds Cc: Jeff Garzik , Russell King , Matt Porter , Jamey Hicks , Ian Molton , linux-kernel@vger.kernel.org, greg@kroah.com, tony@atomide.com, david-b@pacbell.net, joshua@joshuawise.com Subject: Re: DMA API issues In-Reply-To: References: <20040618175902.778e616a.spyro@f2s.com> <20040618110721.B3851@home.com> <40D3356E.8040800@hp.com> <20040618122112.D3851@home.com> <20040618204322.C17516@flint.arm.linux.org.uk> <20040622000838.B7802@flint.arm.linux.org.uk> <40D7941F.3020909@pobox.com> User-Agent: Wanderlust/2.10.1 (Watching The Wheels) SEMI/1.14.5 (Awara-Onsen) FLIM/1.14.5 (Demachiyanagi) APEL/10.6 MULE XEmacs/21.4 (patch 15) (Security Through Obscurity) (i386-suse-linux) MIME-Version: 1.0 (generated by SEMI 1.14.5 - "Awara-Onsen") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1195 Lines: 29 At Mon, 21 Jun 2004 20:26:39 -0700 (PDT), Linus Torvalds wrote: > > On Mon, 21 Jun 2004, Linus Torvalds wrote: > > > > The argument at some point was that some architectures may not even _have_ > > a "struct page" for DMA memory, since it's not "normal" memory (ie "slow > > memory" on m68k). However, I thought we all agreed that such a "struct > > page" could be furnished if that architecture wants so support mmap'ing. > > .. which is not to say that we shouldn't have a "pci_mmap_pages()" thing > _too_. Pretty clearly the easiest interface often is to just map the pages > at mmap() time, and then we should just have a helper function to do that. > > I thought we did one already, but hey, maybe not. I don't think we have such. Russell has once proposed a similar one (but not pci-specific), and I believe it makes sense for many drivers. We can hide the architecture-specific cache handling inside the helper function, too. Takashi - 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/