iommu/sva: Remove PASID to mm lookup function

There is no user of iommu_sva_find() function, remove it so that PASID
allocator can be a simple IDA. Device drivers are expected to store
and keep track of their own PASID metadata.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jason Gunthorpe<jgg@nvidia.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20230322200803.869130-4-jacob.jun.pan@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

Author: Jacob Pan

drivers/iommu/iommu-sva.c

@@ -51,26 +51,6 @@ int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max)
 }
 EXPORT_SYMBOL_GPL(iommu_sva_alloc_pasid);
 
-/* ioasid_find getter() requires 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
- *
- * On success a reference to the mm is taken, and must be released with mmput().
- *
- * Returns the mm corresponding to this PASID, or an error if not found.
- */
-struct mm_struct *iommu_sva_find(ioasid_t pasid)
-{
-	return ioasid_find(&iommu_sva_pasid, pasid, __mmget_not_zero);
-}
-EXPORT_SYMBOL_GPL(iommu_sva_find);
-
 /**
  * iommu_sva_bind_device() - Bind a process address space to a device
  * @dev: the device

drivers/iommu/iommu-sva.h

@@ -9,7 +9,6 @@
 #include <linux/mm_types.h>
 
 int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max);
-struct mm_struct *iommu_sva_find(ioasid_t pasid);
 
 /* I/O Page fault */
 struct device;