| Message ID | 20180920170046.20154-7-jean-philippe.brucker@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | Shared Virtual Addressing for the IOMMU | expand |
Hi, On 09/21/2018 01:00 AM, Jean-Philippe Brucker wrote: > The fault handler will need to find an mm given its PASID. This is the > reason we have an IDR for storing address spaces, so hook it up. > > Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> > --- > drivers/iommu/iommu-sva.c | 26 ++++++++++++++++++++++++++ > include/linux/iommu.h | 7 +++++++ > 2 files changed, 33 insertions(+) > > diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c > index 5ff8967cb213..ee86f00ee1b9 100644 > --- a/drivers/iommu/iommu-sva.c > +++ b/drivers/iommu/iommu-sva.c > @@ -636,6 +636,32 @@ void iommu_sva_unbind_device_all(struct device *dev) > } > EXPORT_SYMBOL_GPL(iommu_sva_unbind_device_all); > > +/** > + * iommu_sva_find() - Find mm associated to the given PASID > + * @pasid: Process Address Space ID assigned to the mm > + * > + * Returns the mm corresponding to this PASID, or NULL if not found. A reference > + * to the mm is taken, and must be released with mmput(). > + */ > +struct mm_struct *iommu_sva_find(int pasid) > +{ > + struct io_mm *io_mm; > + struct mm_struct *mm = NULL; > + > + spin_lock(&iommu_sva_lock); > + io_mm = idr_find(&iommu_pasid_idr, pasid); The same thing here. We can't guarantee that a pointer of mm_struct type is associated with a pasid value when pasid is also used for other purposes. If hardware reports a bad pasid, this function might run into problem. Best regards, Lu Baolu > + if (io_mm && io_mm_get_locked(io_mm)) { > + if (mmget_not_zero(io_mm->mm)) > + mm = io_mm->mm; > + > + io_mm_put_locked(io_mm); > + } > + spin_unlock(&iommu_sva_lock); > + > + return mm; > +} > +EXPORT_SYMBOL_GPL(iommu_sva_find); > + > /** > * iommu_sva_init_device() - Initialize Shared Virtual Addressing for a device > * @dev: the device > diff --git a/include/linux/iommu.h b/include/linux/iommu.h > index 429f3dc37a35..a457650b80de 100644 > --- a/include/linux/iommu.h > +++ b/include/linux/iommu.h > @@ -987,6 +987,8 @@ extern int __iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, > void *drvdata); > extern int __iommu_sva_unbind_device(struct device *dev, int pasid); > extern void iommu_sva_unbind_device_all(struct device *dev); > +extern struct mm_struct *iommu_sva_find(int pasid); > + > #else /* CONFIG_IOMMU_SVA */ > static inline int iommu_sva_init_device(struct device *dev, > unsigned long features, > @@ -1016,6 +1018,11 @@ static inline int __iommu_sva_unbind_device(struct device *dev, int pasid) > static inline void iommu_sva_unbind_device_all(struct device *dev) > { > } > + > +static inline struct mm_struct *iommu_sva_find(int pasid) > +{ > + return NULL; > +} > #endif /* CONFIG_IOMMU_SVA */ > > #endif /* __LINUX_IOMMU_H */ >
diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c index 5ff8967cb213..ee86f00ee1b9 100644 --- a/drivers/iommu/iommu-sva.c +++ b/drivers/iommu/iommu-sva.c @@ -636,6 +636,32 @@ void iommu_sva_unbind_device_all(struct device *dev) } EXPORT_SYMBOL_GPL(iommu_sva_unbind_device_all); +/** + * iommu_sva_find() - Find mm associated to the given PASID + * @pasid: Process Address Space ID assigned to the mm + * + * Returns the mm corresponding to this PASID, or NULL if not found. A reference + * to the mm is taken, and must be released with mmput(). + */ +struct mm_struct *iommu_sva_find(int pasid) +{ + struct io_mm *io_mm; + struct mm_struct *mm = NULL; + + spin_lock(&iommu_sva_lock); + io_mm = idr_find(&iommu_pasid_idr, pasid); + if (io_mm && io_mm_get_locked(io_mm)) { + if (mmget_not_zero(io_mm->mm)) + mm = io_mm->mm; + + io_mm_put_locked(io_mm); + } + spin_unlock(&iommu_sva_lock); + + return mm; +} +EXPORT_SYMBOL_GPL(iommu_sva_find); + /** * iommu_sva_init_device() - Initialize Shared Virtual Addressing for a device * @dev: the device diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 429f3dc37a35..a457650b80de 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -987,6 +987,8 @@ extern int __iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void *drvdata); extern int __iommu_sva_unbind_device(struct device *dev, int pasid); extern void iommu_sva_unbind_device_all(struct device *dev); +extern struct mm_struct *iommu_sva_find(int pasid); + #else /* CONFIG_IOMMU_SVA */ static inline int iommu_sva_init_device(struct device *dev, unsigned long features, @@ -1016,6 +1018,11 @@ static inline int __iommu_sva_unbind_device(struct device *dev, int pasid) static inline void iommu_sva_unbind_device_all(struct device *dev) { } + +static inline struct mm_struct *iommu_sva_find(int pasid) +{ + return NULL; +} #endif /* CONFIG_IOMMU_SVA */ #endif /* __LINUX_IOMMU_H */
The fault handler will need to find an mm given its PASID. This is the reason we have an IDR for storing address spaces, so hook it up. Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> --- drivers/iommu/iommu-sva.c | 26 ++++++++++++++++++++++++++ include/linux/iommu.h | 7 +++++++ 2 files changed, 33 insertions(+)