From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robin Murphy Subject: Re: [PATCH v7 08/10] iommu/dma-reserved_iommu: iommu_msi_mapping_desc_to_domain Date: Wed, 20 Apr 2016 18:19:58 +0100 Message-ID: <5717BA3E.8050901@arm.com> References: <1461084994-2355-1-git-send-email-eric.auger@linaro.org> <1461084994-2355-9-git-send-email-eric.auger@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1461084994-2355-9-git-send-email-eric.auger-QSEj5FYQhm4dnm+yROfE0A@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: Eric Auger , eric.auger-qxv4g6HH51o@public.gmane.org, alex.williamson-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, will.deacon-5wv7dgnIgG8@public.gmane.org, joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org, tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org, jason-NLaQJdtUoK4Be96aLqz0jA@public.gmane.org, marc.zyngier-5wv7dgnIgG8@public.gmane.org, christoffer.dall-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org Cc: julien.grall-5wv7dgnIgG8@public.gmane.org, patches-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, p.fedin-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, pranav.sawargaonkar-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org List-Id: iommu@lists.linux-foundation.org On 19/04/16 17:56, Eric Auger wrote: > This function checks whether > - the device emitting the MSI belongs to a non default iommu domain > - the iommu domain requires the MSI address to be mapped. > > If those conditions are met, the function returns the iommu domain > to be used for mapping the MSI doorbell; else it returns NULL. > > Signed-off-by: Eric Auger > --- > drivers/iommu/dma-reserved-iommu.c | 19 +++++++++++++++++++ > include/linux/dma-reserved-iommu.h | 18 ++++++++++++++++++ > 2 files changed, 37 insertions(+) > > diff --git a/drivers/iommu/dma-reserved-iommu.c b/drivers/iommu/dma-reserved-iommu.c > index 2522235..907a17f 100644 > --- a/drivers/iommu/dma-reserved-iommu.c > +++ b/drivers/iommu/dma-reserved-iommu.c > @@ -17,6 +17,7 @@ > > #include > #include > +#include > > struct reserved_iova_domain { > struct iova_domain *iovad; > @@ -332,3 +333,21 @@ unlock: > } > EXPORT_SYMBOL_GPL(iommu_put_reserved_iova); > > +struct iommu_domain *iommu_msi_mapping_desc_to_domain(struct msi_desc *desc) > +{ > + struct device *dev; > + struct iommu_domain *d; > + > + dev = msi_desc_to_dev(desc); > + > + d = iommu_get_domain_for_dev(dev); > + > + if (!d || (d->type == IOMMU_DOMAIN_DMA)) > + return NULL; > + > + if (iommu_domain_get_attr(d, DOMAIN_ATTR_MSI_MAPPING, NULL)) > + return NULL; Yeah, I don't see why we couldn't just use if (domain->ops->capable(IOMMU_CAP_INTR_REMAP)) return NULL there instead. > + > + return d; > +} > +EXPORT_SYMBOL_GPL(iommu_msi_mapping_desc_to_domain); > diff --git a/include/linux/dma-reserved-iommu.h b/include/linux/dma-reserved-iommu.h > index 8722131..8373929 100644 > --- a/include/linux/dma-reserved-iommu.h > +++ b/include/linux/dma-reserved-iommu.h > @@ -19,6 +19,7 @@ > #include > > struct iommu_domain; > +struct msi_desc; > > #ifdef CONFIG_IOMMU_DMA_RESERVED > > @@ -70,6 +71,17 @@ int iommu_get_reserved_iova(struct iommu_domain *domain, > * if the binding ref count is null, destroy the reserved mapping > */ > void iommu_put_reserved_iova(struct iommu_domain *domain, phys_addr_t addr); > + > +/** > + * iommu_msi_mapping_desc_to_domain: in case the MSI originates from a device > + * upstream to an IOMMU and this IOMMU translates the MSI transaction, > + * this function returns the iommu domain the MSI doorbell address must be > + * mapped in. Else it returns NULL. > + * > + * @desc: msi desc handle > + */ > +struct iommu_domain *iommu_msi_mapping_desc_to_domain(struct msi_desc *desc); > + > #else > > static inline int > @@ -93,5 +105,11 @@ static inline int iommu_get_reserved_iova(struct iommu_domain *domain, > static inline void iommu_put_reserved_iova(struct iommu_domain *domain, > phys_addr_t addr) {} > > +static inline struct iommu_domain * > +iommu_msi_mapping_desc_to_domain(struct msi_desc *desc) > +{ > + return NULL; > +} > + > #endif /* CONFIG_IOMMU_DMA_RESERVED */ > #endif /* __DMA_RESERVED_IOMMU_H */ >