From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932575Ab1JXNIp (ORCPT ); Mon, 24 Oct 2011 09:08:45 -0400 Received: from acsinet15.oracle.com ([141.146.126.227]:63722 "EHLO acsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932169Ab1JXNIn (ORCPT ); Mon, 24 Oct 2011 09:08:43 -0400 Date: Thu, 20 Oct 2011 20:40:31 -0400 From: Konrad Rzeszutek Wilk To: "Eric W. Biederman" , fujita.tomonori@lab.ntt.co.jp Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] x86 swiotlb: Verify we can perform the remapping requested. Message-ID: <20111021004031.GB13687@phenom.dumpdata.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: acsinet22.oracle.com [141.146.126.238] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A090202.4EA56319.019D:SCFMA922111,ss=1,re=-4.000,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 17, 2011 at 02:19:18PM -0700, Eric W. Biederman wrote: > > Recently I had a driver try with a peculiar 2G dma memory limit. > It failed in weird and strange ways because my bounce buffers were > being allocated above 2G where the driver could not reach, and > no error was reported when the mappings were setup. OK, so the overflow buffer was used instead.. which presumarily also was allocated above the 2G? That seems to point that alloc_bootmem_low_pages is not doing its job? > > Use the swiotlb_dma_supported to avoid silent problems like this > in the future. Which driver was it that had this limit? > > Signed-off-by: Eric W. Biederman I also CC-ed Fujita on this as he is the swiotlb maintainer. > --- > arch/x86/kernel/pci-swiotlb.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c > index 8f972cb..6a802fa 100644 > --- a/arch/x86/kernel/pci-swiotlb.c > +++ b/arch/x86/kernel/pci-swiotlb.c > @@ -38,7 +38,7 @@ static struct dma_map_ops swiotlb_dma_ops = { > .unmap_sg = swiotlb_unmap_sg_attrs, > .map_page = swiotlb_map_page, > .unmap_page = swiotlb_unmap_page, > - .dma_supported = NULL, > + .dma_supported = swiotlb_dma_supported, > }; > > /* > -- > 1.7.2.5 > > -- > 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/