Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756371Ab3JJUzL (ORCPT ); Thu, 10 Oct 2013 16:55:11 -0400 Received: from mx1.redhat.com ([209.132.183.28]:6751 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755703Ab3JJUzI (ORCPT ); Thu, 10 Oct 2013 16:55:08 -0400 Message-ID: <1381438469.2796.58.camel@ul30vt.home> Subject: Re: [PATCH v10 20/20] iommu/exynos: add devices attached to the System MMU to an IOMMU group From: Alex Williamson To: Cho KyongHo Cc: Linux ARM Kernel , Linux DeviceTree , Linux IOMMU , Linux Kernel , Linux Samsung SOC , Antonios Motakis , Grant Grundler , Joerg Roedel , Kukjin Kim , Prathyush , Rahul Sharma , Sachin Kamat , Subash Patel , Varun Sethi , Sylwester Nawrocki , Tomasz Figa Date: Thu, 10 Oct 2013 14:54:29 -0600 In-Reply-To: <20131007105844.a260f37a9a941bed894adca3@samsung.com> References: <20131007105844.a260f37a9a941bed894adca3@samsung.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2420 Lines: 75 On Mon, 2013-10-07 at 10:58 +0900, Cho KyongHo wrote: > Patch written by Antonios Motakis : > > IOMMU groups are expected by certain users of the IOMMU API, > e.g. VFIO. Since each device is behind its own System MMU, we > can allocate a new IOMMU group for each device. > > Reviewd-by: Cho KyongHo > Signed-off-by: Antonios Motakis > --- > drivers/iommu/exynos-iommu.c | 28 ++++++++++++++++++++++++++++ > 1 files changed, 28 insertions(+), 0 deletions(-) > > diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c > index 5025338..24505a0 100644 > --- a/drivers/iommu/exynos-iommu.c > +++ b/drivers/iommu/exynos-iommu.c > @@ -1028,6 +1028,32 @@ static phys_addr_t exynos_iommu_iova_to_phys(struct iommu_domain *domain, > return phys; > } > > +static int exynos_iommu_add_device(struct device *dev) > +{ > + struct iommu_group *group; > + int ret; > + > + group = iommu_group_get(dev); Seems reasonable, my only nit would be whether it's really an error to get a group back from the above call. If devices are always isolated and IOMMU groups are always singleton, it would be an error to find one already associated with the device. Right? Thanks, Alex > + > + if (!group) { > + group = iommu_group_alloc(); > + if (IS_ERR(group)) { > + dev_err(dev, "Failed to allocate IOMMU group\n"); > + return PTR_ERR(group); > + } > + } > + > + ret = iommu_group_add_device(group, dev); > + iommu_group_put(group); > + > + return ret; > +} > + > +static void exynos_iommu_remove_device(struct device *dev) > +{ > + iommu_group_remove_device(dev); > +} > + > static struct iommu_ops exynos_iommu_ops = { > .domain_init = &exynos_iommu_domain_init, > .domain_destroy = &exynos_iommu_domain_destroy, > @@ -1036,6 +1062,8 @@ static struct iommu_ops exynos_iommu_ops = { > .map = &exynos_iommu_map, > .unmap = &exynos_iommu_unmap, > .iova_to_phys = &exynos_iommu_iova_to_phys, > + .add_device = &exynos_iommu_add_device, > + .remove_device = &exynos_iommu_remove_device, > .pgsize_bitmap = SECT_SIZE | LPAGE_SIZE | SPAGE_SIZE, > }; > -- 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/