From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Williamson Subject: Re: [PATCH 2/7] iommu: add api to get iommu_domain of a device Date: Wed, 25 Sep 2013 10:45:33 -0600 Message-ID: <1380127533.3030.319.camel@ul30vt.home> References: <1379575763-2091-1-git-send-email-Bharat.Bhushan@freescale.com> <1379575763-2091-3-git-send-email-Bharat.Bhushan@freescale.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1379575763-2091-3-git-send-email-Bharat.Bhushan-KZfg59tc24xl57MIdRCFDg@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Bharat Bhushan Cc: agraf-l3A5Bk7waGM@public.gmane.org, linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, galak-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, benh-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org, scottwood-KZfg59tc24xl57MIdRCFDg@public.gmane.org, linuxppc-dev-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org List-Id: iommu@lists.linux-foundation.org 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;