From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2A2EBC76191 for ; Wed, 24 Jul 2019 17:23:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EB6D0229F3 for ; Wed, 24 Jul 2019 17:23:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728281AbfGXRXz (ORCPT ); Wed, 24 Jul 2019 13:23:55 -0400 Received: from mx2.suse.de ([195.135.220.15]:54190 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2387421AbfGXRXy (ORCPT ); Wed, 24 Jul 2019 13:23:54 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 1E42DAE2E; Wed, 24 Jul 2019 17:23:53 +0000 (UTC) Message-ID: Subject: Re: [PATCH 2/2] arm: use swiotlb for bounce buffer on LPAE configs From: Nicolas Saenz Julienne To: Christoph Hellwig , Russell King - ARM Linux admin Cc: Vignesh Raghavendra , Konrad Rzeszutek Wilk , linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, Roger Quadros Date: Wed, 24 Jul 2019 19:23:50 +0200 In-Reply-To: <20190709142011.24984-3-hch@lst.de> References: <20190709142011.24984-1-hch@lst.de> <20190709142011.24984-3-hch@lst.de> Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-whG6SPAwfjFfvDK3372+" User-Agent: Evolution 3.32.3 MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-whG6SPAwfjFfvDK3372+ Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, 2019-07-09 at 07:20 -0700, Christoph Hellwig wrote: > The DMA API requires that 32-bit DMA masks are always supported, but on > arm LPAE configs they do not currently work when memory is present > above 4GB. Wire up the swiotlb code like for all other architectures > to provide the bounce buffering in that case. >=20 > Fixes: 21e07dba9fb11 ("scsi: reduce use of block bounce buffers"). > Reported-by: Roger Quadros > Signed-off-by: Christoph Hellwig > --- Hi Chistoph, Out of curiosity, what is the reason stopping us from using dma-direct/swio= tlb instead of arm_dma_ops altogether? Regards, Nicolas --=-whG6SPAwfjFfvDK3372+ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEErOkkGDHCg2EbPcGjlfZmHno8x/4FAl04lCcACgkQlfZmHno8 x/5jKAgAszLIqjIi52NyfR8TyZ+bPsWKIAQKAn5HBQa6grZi+PtHDVbHAxKTikMQ PgjbRl5aI7uPsbYFuq8R6jr+2mQLXI7gvgHn2x22hh+3+cC+mYWJoORNg7v5VrI9 c2Q4FaZcHLxPLNjPNLsJJHyrM8wLiZ9bMbpKpQ8Fs0UoJmD9fefIDXRIHYQTakeZ ooLgoUnyEje4u1jCI8dbJrDXRxzVwF7CYlY6V5+PG+7GrdP6sqYeNDk1+PAtzUtf EIRenYS6MAHo3skOiC+Egr/DeYEsk72iZzIZpWKm7k0HGX9kSc6+eWXt6lPwyiqq 22EzPtQpZAz/Jim+FmDtgz/5II5T+g== =3iIi -----END PGP SIGNATURE----- --=-whG6SPAwfjFfvDK3372+--