| Message ID | 20180212183352.22730-5-jean-philippe.brucker@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
> From: Jean-Philippe Brucker > Sent: Tuesday, February 13, 2018 2:33 AM > > 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. what about registering the callback in sva_device_init? > > Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> > --- > 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
On 13/02/18 08:11, Tian, Kevin wrote: >> From: Jean-Philippe Brucker >> Sent: Tuesday, February 13, 2018 2:33 AM >> >> 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. > > what about registering the callback in sva_device_init? I don't have a preference. This way it look like iommu_register_device_fault_handler, but adding the callback to sva_device_init makes sense too. Thanks, Jean
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 */
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 <jean-philippe.brucker@arm.com> --- drivers/iommu/iommu-sva.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++ include/linux/iommu.h | 18 ++++++++++++++++ 2 files changed, 72 insertions(+)