Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758928AbXJYLZA (ORCPT ); Thu, 25 Oct 2007 07:25:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755106AbXJYLYw (ORCPT ); Thu, 25 Oct 2007 07:24:52 -0400 Received: from mail.sf-mail.de ([62.27.20.61]:36231 "EHLO mail.sf-mail.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753007AbXJYLYv (ORCPT ); Thu, 25 Oct 2007 07:24:51 -0400 From: Rolf Eike Beer To: Jens Axboe Subject: Re: [PATCH 2.6.24-rc1] fix sg_phys to use dma_addr_t Date: Thu, 25 Oct 2007 13:24:38 +0200 User-Agent: KMail/1.9.6 (enterprise 20070904.708012) Cc: Arjan van de Ven , Hugh Dickins , linux-kernel@vger.kernel.org References: <200710251100.29739.eike-kernel@sf-tec.de> <20071025090646.GI5053@kernel.dk> In-Reply-To: <20071025090646.GI5053@kernel.dk> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart1481609.6DQFjXFsSr"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Message-Id: <200710251324.45776.eike-kernel@sf-tec.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2240 Lines: 57 --nextPart1481609.6DQFjXFsSr Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Disposition: inline Jens Axboe wrote: > On Thu, Oct 25 2007, Rolf Eike Beer wrote: > > Jens Axboe wrote: > > > On Thu, Oct 25 2007, Rolf Eike Beer wrote: > > > > Am Donnerstag, 25. Oktober 2007 schrieb Arjan van de Ven: > > > > > > Signed-off-by: Hugh Dickins > > > > > > --- > > > > > > Whether this is a complete patch, suitable for all architectures, > > > > > > I'm not sure: it builds, boots and runs correctly on the x86_32 > > > > > > box in question, but you'll be a lot wiser than me about using > > > > > > dma_addr_t for everyone. (Seems a bit of a shame to include > > > > > > here, when I think all arches already get to > > > > > > include it one way or another, typically via asm/scatterlist.h; > > > > > > but I guess it's safest to repeat it.) > > > > > > > > > > there is a problem with this... sg_phys doesn't return an actual > > > > > *dma* address.... at least not an address you can give to the > > > > > device. Using dma_addr_t is thus a bit misleading..... > > > > > > > > Ok, then: how do I actually get such an address? > > > > > > You use the dma mapping api, Documentation/DMA-mapping.txt > > > > Which comes back always to the same point: if I get a buffer from > > userspace to use for DMA: what can I do then? I need to convert a > > given list of (physical, pinned) pages to DMA addresses. > > get_user_pages() -> fill in sg table -> pci/dma_map_sg() So the answer to the first question should have been sg_dma_address() ;) Eike --nextPart1481609.6DQFjXFsSr Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4-svn0 (GNU/Linux) iD8DBQBHIHz9XKSJPmm5/E4RAmo7AJ9b6YWqxlGPnNYD8RIoo4DepereLQCgoOG9 wRFJhbZZdJrkkO9UPz1lLkY= =uSoA -----END PGP SIGNATURE----- --nextPart1481609.6DQFjXFsSr-- - 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/