[PATCH v4 04/26] iommu/sva: Search mm by PASID
From: Jean-Philippe Brucker <hidden>
Date: 2020-02-24 18:24:41
Also in:
linux-devicetree, linux-iommu, linux-mm, linux-pci
Subsystem:
iommu subsystem, the rest · Maintainers:
Joerg Roedel, Will Deacon, Linus Torvalds
From: Jean-Philippe Brucker <redacted> 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 <redacted> --- drivers/iommu/iommu-sva.c | 19 +++++++++++++++++++ include/linux/iommu.h | 9 +++++++++ 2 files changed, 28 insertions(+)
diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c
index 64f1d1c82383..bfd0c477f290 100644
--- a/drivers/iommu/iommu-sva.c
+++ b/drivers/iommu/iommu-sva.c@@ -559,3 +559,22 @@ int iommu_sva_get_pasid_generic(struct iommu_sva *handle) return pasid; } EXPORT_SYMBOL_GPL(iommu_sva_get_pasid_generic); + +/* ioasid wants a void * argument */ +static bool __mmget_not_zero(void *mm) +{ + return mmget_not_zero(mm); +} + +/** + * 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 an error if not found. A + * reference to the mm is taken, and must be released with mmput(). + */ +struct mm_struct *iommu_sva_find(int pasid) +{ + return ioasid_find(&shared_pasid, pasid, __mmget_not_zero); +} +EXPORT_SYMBOL_GPL(iommu_sva_find);
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index e7bc47ba24f8..e52a8731e7a9 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h@@ -1091,6 +1091,15 @@ void iommu_debugfs_setup(void); static inline void iommu_debugfs_setup(void) {} #endif +#ifdef CONFIG_IOMMU_SVA +extern struct mm_struct *iommu_sva_find(int pasid); +#else /* !CONFIG_IOMMU_SVA */ +static inline struct mm_struct *iommu_sva_find(int pasid) +{ + return NULL; +} +#endif /* !CONFIG_IOMMU_SVA */ + #ifdef CONFIG_IOMMU_PAGE_FAULT extern int iommu_queue_iopf(struct iommu_fault *fault, void *cookie);
--
2.25.0
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