Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751428Ab3IYQpt (ORCPT ); Wed, 25 Sep 2013 12:45:49 -0400 Received: from mx1.redhat.com ([209.132.183.28]:11224 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750845Ab3IYQps (ORCPT ); Wed, 25 Sep 2013 12:45:48 -0400 Message-ID: <1380127533.3030.319.camel@ul30vt.home> Subject: Re: [PATCH 2/7] iommu: add api to get iommu_domain of a device From: Alex Williamson To: Bharat Bhushan Cc: joro@8bytes.org, benh@kernel.crashing.org, galak@kernel.crashing.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-pci@vger.kernel.org, agraf@suse.de, scottwood@freescale.com, iommu@lists.linux-foundation.org, Bharat Bhushan Date: Wed, 25 Sep 2013 10:45:33 -0600 In-Reply-To: <1379575763-2091-3-git-send-email-Bharat.Bhushan@freescale.com> References: <1379575763-2091-1-git-send-email-Bharat.Bhushan@freescale.com> <1379575763-2091-3-git-send-email-Bharat.Bhushan@freescale.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: 2921 Lines: 77 On Thu, 2013-09-19 at 12:59 +0530, Bharat Bhushan wrote: > This api return the iommu domain to which the device is attached. > The iommu_domain is required for making API calls related to iommu. > Follow up patches which use this API to know iommu maping. > > Signed-off-by: Bharat Bhushan > --- > drivers/iommu/iommu.c | 10 ++++++++++ > include/linux/iommu.h | 7 +++++++ > 2 files changed, 17 insertions(+), 0 deletions(-) > > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c > index fbe9ca7..6ac5f50 100644 > --- a/drivers/iommu/iommu.c > +++ b/drivers/iommu/iommu.c > @@ -696,6 +696,16 @@ void iommu_detach_device(struct iommu_domain *domain, struct device *dev) > } > EXPORT_SYMBOL_GPL(iommu_detach_device); > > +struct iommu_domain *iommu_get_dev_domain(struct device *dev) > +{ > + struct iommu_ops *ops = dev->bus->iommu_ops; > + > + if (unlikely(ops == NULL || ops->get_dev_iommu_domain == NULL)) > + return NULL; > + > + return ops->get_dev_iommu_domain(dev); > +} > +EXPORT_SYMBOL_GPL(iommu_get_dev_domain); What prevents this from racing iommu_domain_free()? There's no references acquired, so there's no reason for the caller to assume the pointer is valid. > /* > * IOMMU groups are really the natrual working unit of the IOMMU, but > * the IOMMU API works on domains and devices. Bridge that gap by > diff --git a/include/linux/iommu.h b/include/linux/iommu.h > index 7ea319e..fa046bd 100644 > --- a/include/linux/iommu.h > +++ b/include/linux/iommu.h > @@ -127,6 +127,7 @@ struct iommu_ops { > int (*domain_set_windows)(struct iommu_domain *domain, u32 w_count); > /* Get the numer of window per domain */ > u32 (*domain_get_windows)(struct iommu_domain *domain); > + struct iommu_domain *(*get_dev_iommu_domain)(struct device *dev); > > unsigned long pgsize_bitmap; > }; > @@ -190,6 +191,7 @@ extern int iommu_domain_window_enable(struct iommu_domain *domain, u32 wnd_nr, > phys_addr_t offset, u64 size, > int prot); > extern void iommu_domain_window_disable(struct iommu_domain *domain, u32 wnd_nr); > +extern struct iommu_domain *iommu_get_dev_domain(struct device *dev); > /** > * report_iommu_fault() - report about an IOMMU fault to the IOMMU framework > * @domain: the iommu domain where the fault has happened > @@ -284,6 +286,11 @@ static inline void iommu_domain_window_disable(struct iommu_domain *domain, > { > } > > +static inline struct iommu_domain *iommu_get_dev_domain(struct device *dev) > +{ > + return NULL; > +} > + > static inline phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain, dma_addr_t iova) > { > return 0; -- 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/