From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean-Philippe Brucker Subject: [PATCH 04/37] iommu/sva: Add a mm_exit callback for device drivers Date: Mon, 12 Feb 2018 18:33:19 +0000 Message-ID: <20180212183352.22730-5-jean-philippe.brucker@arm.com> References: <20180212183352.22730-1-jean-philippe.brucker@arm.com> Return-path: In-Reply-To: <20180212183352.22730-1-jean-philippe.brucker-5wv7dgnIgG8@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-acpi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org, robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, catalin.marinas-5wv7dgnIgG8@public.gmane.org, will.deacon-5wv7dgnIgG8@public.gmane.org, lorenzo.pieralisi-5wv7dgnIgG8@public.gmane.org, hanjun.guo-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, sudeep.holla-5wv7dgnIgG8@public.gmane.org, rjw-LthD3rsA81gm4RdzfppkhA@public.gmane.org, lenb-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, robin.murphy-5wv7dgnIgG8@public.gmane.org, bhelgaas-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, alex.williamson-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, tn-nYOzD4b6Jr9Wk0Htik3J/w@public.gmane.org, liubo95-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, thunder.leizhen-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, xieyisheng1-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, xuzaibo-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, ilias.apalodimas-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, jonathan.cameron-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, shunyong.yang-PT9Dzx9SjPiXmMXjJBpWqg@public.gmane.org, nwatters-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, okaya-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, jcrouse-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, rfranz-YGCgFSpz5w/QT0dZR+AlfA@public.gmane.org, dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, jacob.jun.pan-VuQAYsv1563Yd54FQh9/CA@public.gmane.org, yi.l.liu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, ashok.raj-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, robdclark-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, christian.koenig-5C7GfCeVMHo@public.gmane.org, bharatku-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org List-Id: devicetree@vger.kernel.org When an mm exits, devices that were bound to it must stop performing DMA on its PASID. Let device drivers register a callback to be notified on mm exit. Add the callback to the iommu_param structure attached to struct device. Signed-off-by: Jean-Philippe Brucker --- drivers/iommu/iommu-sva.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++ include/linux/iommu.h | 18 ++++++++++++++++ 2 files changed, 72 insertions(+) diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c index f9af9d66b3ed..90b524c99d3d 100644 --- a/drivers/iommu/iommu-sva.c +++ b/drivers/iommu/iommu-sva.c @@ -569,3 +569,57 @@ void __iommu_sva_unbind_dev_all(struct device *dev) spin_unlock(&iommu_sva_lock); } EXPORT_SYMBOL_GPL(__iommu_sva_unbind_dev_all); + +/** + * iommu_register_mm_exit_handler() - Set a callback for mm exit + * @dev: the device + * @handler: exit handler + * + * Users of the bind/unbind API should call this function to set a + * device-specific callback telling them when a mm is exiting. + * + * After the callback returns, the device must not issue any more transaction + * with the PASID given as argument to the handler. In addition the handler gets + * an opaque pointer corresponding to the drvdata passed as argument of bind(). + * + * The handler itself should return 0 on success, and an appropriate error code + * otherwise. + */ +int iommu_register_mm_exit_handler(struct device *dev, + iommu_mm_exit_handler_t handler) +{ + struct iommu_param *dev_param = dev->iommu_param; + + if (!dev_param) + return -EINVAL; + + /* + * FIXME: racy. Same as iommu_sva_device_init, but here we'll need a + * spinlock to call the mm_exit param from atomic context. + */ + if (dev_param->mm_exit) + return -EBUSY; + + get_device(dev); + dev_param->mm_exit = handler; + + return 0; +} +EXPORT_SYMBOL_GPL(iommu_register_mm_exit_handler); + +/** + * iommu_unregister_mm_exit_handler() - Remove mm exit callback + */ +int iommu_unregister_mm_exit_handler(struct device *dev) +{ + struct iommu_param *dev_param = dev->iommu_param; + + if (!dev_param || !dev_param->mm_exit) + return -EINVAL; + + dev_param->mm_exit = NULL; + put_device(dev); + + return 0; +} +EXPORT_SYMBOL_GPL(iommu_unregister_mm_exit_handler); diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 09d85f44142a..1b1a16892ac1 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -65,6 +65,8 @@ typedef int (*iommu_dev_fault_handler_t)(struct iommu_fault_event *, void *); /* Request I/O page fault support */ #define IOMMU_SVA_FEAT_IOPF (1 << 1) +typedef int (*iommu_mm_exit_handler_t)(struct device *dev, int pasid, void *); + struct iommu_domain_geometry { dma_addr_t aperture_start; /* First address that can be mapped */ dma_addr_t aperture_end; /* Last address that can be mapped */ @@ -424,6 +426,7 @@ struct iommu_param { unsigned int min_pasid; unsigned int max_pasid; struct list_head mm_list; + iommu_mm_exit_handler_t mm_exit; }; int iommu_device_register(struct iommu_device *iommu); @@ -941,6 +944,10 @@ extern int iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, int *pasid, unsigned long flags, void *drvdata); extern int iommu_sva_unbind_device(struct device *dev, int pasid); extern void __iommu_sva_unbind_dev_all(struct device *dev); +extern int iommu_register_mm_exit_handler(struct device *dev, + iommu_mm_exit_handler_t handler); +extern int iommu_unregister_mm_exit_handler(struct device *dev); + #else /* CONFIG_IOMMU_SVA */ static inline int iommu_sva_device_init(struct device *dev, unsigned long features, @@ -969,6 +976,17 @@ static inline int iommu_sva_unbind_device(struct device *dev, int pasid) static inline void __iommu_sva_unbind_dev_all(struct device *dev) { } + +static inline int iommu_register_mm_exit_handler(struct device *dev, + iommu_mm_exit_handler_t handler) +{ + return -ENODEV; +} + +static inline int iommu_unregister_mm_exit_handler(struct device *dev) +{ + return -ENODEV; +} #endif /* CONFIG_IOMMU_SVA */ #endif /* __LINUX_IOMMU_H */ -- 2.15.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html