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 sva_param structure attached to struct device.
Signed-off-by: Jean-Philippe Brucker <[email protected]> --- drivers/iommu/iommu-sva.c | 10 +++++++++- include/linux/iommu.h | 8 ++++++-- 2 files changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c index a486bc947335..08da479dad68 100644 --- a/drivers/iommu/iommu-sva.c +++ b/drivers/iommu/iommu-sva.c @@ -436,6 +436,7 @@ EXPORT_SYMBOL_GPL(iommu_sva_unbind_device_all); * @features: bitmask of features that need to be initialized * @min_pasid: min PASID value supported by the device * @max_pasid: max PASID value supported by the device + * @mm_exit: callback for process address space release * * Users of the bind()/unbind() API must call this function to initialize all * features required for SVA. @@ -447,13 +448,19 @@ EXPORT_SYMBOL_GPL(iommu_sva_unbind_device_all); * overrides it. Similarly, @min_pasid overrides the lower PASID limit supported * by the IOMMU. * + * @mm_exit is called when an address space bound to the device is about to be + * torn down by exit_mmap. After @mm_exit returns, the device must not issue any + * more transaction with the PASID given as argument. The handler gets an opaque + * pointer corresponding to the drvdata passed as argument to bind(). + * * The device should not be performing any DMA while this function is running, * otherwise the behavior is undefined. * * Return 0 if initialization succeeded, or an error. */ int iommu_sva_init_device(struct device *dev, unsigned long features, - unsigned int min_pasid, unsigned int max_pasid) + unsigned int min_pasid, unsigned int max_pasid, + iommu_mm_exit_handler_t mm_exit) { int ret; struct iommu_sva_param *param; @@ -472,6 +479,7 @@ int iommu_sva_init_device(struct device *dev, unsigned long features, param->features = features; param->min_pasid = min_pasid; param->max_pasid = max_pasid; + param->mm_exit = mm_exit; INIT_LIST_HEAD(¶m->mm_list); mutex_lock(&dev->iommu_param->sva_lock); diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 6a3ced6a5aa1..c95ff714ea66 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -60,6 +60,7 @@ struct iommu_fault_event; typedef int (*iommu_fault_handler_t)(struct iommu_domain *, struct device *, unsigned long, int, void *); typedef int (*iommu_dev_fault_handler_t)(struct iommu_fault_event *, void *); +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 */ @@ -216,6 +217,7 @@ struct iommu_sva_param { unsigned int min_pasid; unsigned int max_pasid; struct list_head mm_list; + iommu_mm_exit_handler_t mm_exit; }; /** @@ -967,7 +969,8 @@ static inline void iommu_debugfs_setup(void) {} #ifdef CONFIG_IOMMU_SVA extern int iommu_sva_init_device(struct device *dev, unsigned long features, unsigned int min_pasid, - unsigned int max_pasid); + unsigned int max_pasid, + iommu_mm_exit_handler_t mm_exit); extern void iommu_sva_shutdown_device(struct device *dev); extern int __iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, int *pasid, unsigned long flags, @@ -978,7 +981,8 @@ extern void iommu_sva_unbind_device_all(struct device *dev); static inline int iommu_sva_init_device(struct device *dev, unsigned long features, unsigned int min_pasid, - unsigned int max_pasid) + unsigned int max_pasid, + iommu_mm_exit_handler_t mm_exit) { return -ENODEV; } -- 2.18.0 _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
