> -----Original Message----- > From: linux-pci-owner@xxxxxxxxxxxxxxx [mailto:linux-pci-owner@xxxxxxxxxxxxxxx] > On Behalf Of Alex Williamson > Sent: Wednesday, September 25, 2013 10:16 PM > To: Bhushan Bharat-R65777 > Cc: joro@xxxxxxxxxx; benh@xxxxxxxxxxxxxxxxxxx; galak@xxxxxxxxxxxxxxxxxxx; linux- > kernel@xxxxxxxxxxxxxxx; linuxppc-dev@xxxxxxxxxxxxxxxx; linux- > pci@xxxxxxxxxxxxxxx; agraf@xxxxxxx; Wood Scott-B07421; iommu@lists.linux- > foundation.org; Bhushan Bharat-R65777 > Subject: Re: [PATCH 2/7] iommu: add api to get iommu_domain of a device > > 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 <bharat.bhushan@xxxxxxxxxxxxx> > > --- > > 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. Sorry for late query, somehow this email went into a folder and escaped; Just to be sure, there is not lock at generic "struct iommu_domain", but IP specific structure (link FSL domain) linked in iommu_domain->priv have a lock, so we need to ensure this race in FSL iommu code (say drivers/iommu/fsl_pamu_domain.c), right? Thanks -Bharat > > > /* > > * 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-pci" in the body > of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at > http://vger.kernel.org/majordomo-info.html ��.n��������+%������w��{.n�����{���"�)�� jg��� �����ݢj����G���� ���j:+v���w�m������w�������h�����٥
