From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 16 Nov 2001 09:33:56 +0100 From: Jens Axboe Subject: Re: parisc scatterlist doesn't want page/offset Message-ID: <20011116093356.D27010@suse.de> References: <200111160730.AAA18774@puffin.external.hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200111160730.AAA18774@puffin.external.hp.com> Sender: owner-linux-mm@kvack.org Return-Path: To: Grant Grundler Cc: "David S. Miller" , linux-mm@kvack.org, parisc-linux@lists.parisc-linux.org List-ID: On Fri, Nov 16 2001, Grant Grundler wrote: > Hi all, > Could someone point me to any discussion about adding > page/offset to struct scatterlist? See lkml a couple months back, 32-bit dma etc discussion. > > To me, it looks like a half-assed step to support DMA to HIGHMEM > on 32-bit arches. TBH, I'd like to see page/offset replace > address in the pci_map* interfaces and struct scatterlist. > But then replace it across the board so the DMA mapping code > doesn't have to decide which field to use (KISS). This really > belongs in 2.5 kernel. It's not half-assed, it's needed. I would imagine that pci_map_single etc stays though, although pci_map_page or pci_map_sg is the preferred approach. Regarding the patch -- please add a helper function to set the sg list instead of introducing CONFIG_HIGHMEM all over the place. I'm assuming you are missing the piece which leaves out page/offset for non-highmem, if not you are really pedantic about saving a few cycles :-) -- Jens Axboe -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/