Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752453AbaBXMTT (ORCPT ); Mon, 24 Feb 2014 07:19:19 -0500 Received: from smtp02.citrix.com ([66.165.176.63]:11138 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751450AbaBXMTS (ORCPT ); Mon, 24 Feb 2014 07:19:18 -0500 X-IronPort-AV: E=Sophos;i="4.97,534,1389744000"; d="scan'208";a="103507957" Date: Mon, 24 Feb 2014 12:19:11 +0000 From: Stefano Stabellini X-X-Sender: sstabellini@kaball.uk.xensource.com To: Ian Campbell CC: Julien Grall , , , , , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Rob Landley , Russell King , , "gregkh@linuxfoundation.org" Subject: Re: [PATCH 2/2] arm/xen: Don't use xen DMA ops when the device is protected by an IOMMU In-Reply-To: <1392914159.32657.18.camel@kazak.uk.xensource.com> Message-ID: References: <1392913301-25524-1-git-send-email-julien.grall@linaro.org> <1392914159.32657.18.camel@kazak.uk.xensource.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" X-DLP: MIA2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org CC'ing Greg. On Thu, 20 Feb 2014, Ian Campbell wrote: > On Thu, 2014-02-20 at 16:21 +0000, Julien Grall wrote: > > Only Xen is able to know if a device can safely avoid to use xen-swiotlb. > > This patch introduce a new property "protected-devices" for the hypervisor > > node which list device which the IOMMU are been correctly programmed by Xen. > > > > During Linux boot, Xen specific code will create an hash table which > > contains all these devices. The hash table will be used in need_xen_dma_ops > > to check if the Xen DMA ops needs to be used for the current device. > > Is it out of the question to find a field within struct device itself to > store this e.g. in struct device_dma_parameters perhaps and avoid the > need for a hashtable lookup. > > device->iommu_group might be another option, if we can create our own > group? I agree that a field in struct device would be ideal. Greg, get_maintainer.pl points at you as main maintainer of device.h, do you have an opinion on this? -- 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/