Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933717AbaKSVHI (ORCPT ); Wed, 19 Nov 2014 16:07:08 -0500 Received: from aserp1040.oracle.com ([141.146.126.69]:17425 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932793AbaKSVHE (ORCPT ); Wed, 19 Nov 2014 16:07:04 -0500 Date: Wed, 19 Nov 2014 16:06:26 -0500 From: Konrad Rzeszutek Wilk To: Stefano Stabellini Cc: xen-devel@lists.xensource.com, Ian.Campbell@citrix.com, david.vrabel@citrix.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com Subject: Re: [PATCH v9 13/13] swiotlb-xen: remove BUG_ON in xen_bus_to_phys Message-ID: <20141119210626.GD20440@laptop.dumpdata.com> References: <1415792454-23161-13-git-send-email-stefano.stabellini@eu.citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1415792454-23161-13-git-send-email-stefano.stabellini@eu.citrix.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-Source-IP: acsinet21.oracle.com [141.146.126.237] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 12, 2014 at 11:40:54AM +0000, Stefano Stabellini wrote: > On x86 truncation cannot occur because config XEN depends on X86_64 || > (X86_32 && X86_PAE). > > On ARM truncation can occur without CONFIG_ARM_LPAE, when the dma > operation involves foreign grants. However in that case the physical > address returned by xen_bus_to_phys is actually invalid (there is no mfn > to pfn tracking for foreign grants on ARM) and it is not used. > > Signed-off-by: Stefano Stabellini > Reviewed-by: Catalin Marinas Acked-by: Konrad Rzeszutek Wilk > --- > drivers/xen/swiotlb-xen.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c > index 498b654..153cf14 100644 > --- a/drivers/xen/swiotlb-xen.c > +++ b/drivers/xen/swiotlb-xen.c > @@ -96,8 +96,6 @@ static inline phys_addr_t xen_bus_to_phys(dma_addr_t baddr) > dma_addr_t dma = (dma_addr_t)pfn << PAGE_SHIFT; > phys_addr_t paddr = dma; > > - BUG_ON(paddr != dma); /* truncation has occurred, should never happen */ > - > paddr |= baddr & ~PAGE_MASK; > > return paddr; > -- > 1.7.10.4 > -- 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/