From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932312AbZHLJgY (ORCPT ); Wed, 12 Aug 2009 05:36:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752224AbZHLJgY (ORCPT ); Wed, 12 Aug 2009 05:36:24 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:48524 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751998AbZHLJgX (ORCPT ); Wed, 12 Aug 2009 05:36:23 -0400 Subject: Re: [RFC patch] init default dma_ops to prepare intel_iommu_init failure From: David Woodhouse To: Luming Yu Cc: "Yu, Fenghua" , "Luck, Tony" , LKML , Andrew Morton In-Reply-To: <3877989d0908120220q5104d2e7rd272ececbc45e377@mail.gmail.com> References: <3877989d0908120220q5104d2e7rd272ececbc45e377@mail.gmail.com> Content-Type: text/plain Date: Wed, 12 Aug 2009 10:36:08 +0100 Message-Id: <1250069768.29180.85.camel@macbook.infradead.org> Mime-Version: 1.0 X-Mailer: Evolution 2.26.3 (2.26.3-1.fc11) Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2009-08-12 at 17:20 +0800, Luming Yu wrote: > Hi there, > > On ia64 platform with dmar table and new upstream > kernel(config_dmar_default_on enabled), > if intel_iommu_init ends up without dma_ops initialized or other iommu > failures. > We got nothing to fall back. The following patch fixes it. Hm, don't we then end up with a 64MiB allocation for swiotlb buffers which we don't need? We can't defer the allocation until we know -- I think we need to come up with some way to give it _back_ if the swiotlb turns out not to be needed? And we should do this for i386/x86_64 too. -- David Woodhouse Open Source Technology Centre David.Woodhouse@intel.com Intel Corporation