[PATCH v11 2/7] iommufd: Allow passing in iopt_access_list_id to iopt_remove_access()

[Nicolin Chen]

This is a preparatory change for ioas replacement support for access.
The replacement routine does an iopt_add_access() at a new IOAS first
and then iopt_remove_access() at the old IOAS upon the success of the
first call. However, the first call overrides the iopt_access_list_id
in the access struct, resulting in that id un-erased in the xarray.

Add an iopt_access_list_id in iopt_remove_access, so the replacement
routine can save the id before it gets overwritten, and pass the id
in iopt_remove_access() for a proper cleanup.

The existing callers should just pass in access->iopt_access_list_id.

Suggested-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
---
 drivers/iommu/iommufd/device.c          | 6 ++++--
 drivers/iommu/iommufd/io_pagetable.c    | 6 +++---
 drivers/iommu/iommufd/iommufd_private.h | 3 ++-
 3 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
index 57c0e81f5073..7a3e8660b902 100644
--- a/drivers/iommu/iommufd/device.c
+++ b/drivers/iommu/iommufd/device.c
@@ -690,7 +690,8 @@ void iommufd_access_destroy_object(struct iommufd_object *obj)
 		container_of(obj, struct iommufd_access, obj);
 
 	if (access->ioas) {
-		iopt_remove_access(&access->ioas->iopt, access);
+		iopt_remove_access(&access->ioas->iopt, access,
+				   access->iopt_access_list_id);
 		refcount_dec(&access->ioas->obj.users);
 		access->ioas = NULL;
 	}
@@ -776,7 +777,8 @@ void iommufd_access_detach(struct iommufd_access *access)
 		access->ops->unmap(access->data, 0, ULONG_MAX);
 		mutex_lock(&access->ioas_lock);
 	}
-	iopt_remove_access(&cur_ioas->iopt, access);
+	iopt_remove_access(&cur_ioas->iopt, access,
+			   access->iopt_access_list_id);
 	refcount_dec(&cur_ioas->obj.users);
 out:
 	access->ioas_unpin = NULL;
diff --git a/drivers/iommu/iommufd/io_pagetable.c b/drivers/iommu/iommufd/io_pagetable.c
index 4d095115c2d0..3a598182b761 100644
--- a/drivers/iommu/iommufd/io_pagetable.c
+++ b/drivers/iommu/iommufd/io_pagetable.c
@@ -1158,12 +1158,12 @@ int iopt_add_access(struct io_pagetable *iopt, struct iommufd_access *access)
 }
 
 void iopt_remove_access(struct io_pagetable *iopt,
-			struct iommufd_access *access)
+			struct iommufd_access *access,
+			u32 iopt_access_list_id)
 {
 	down_write(&iopt->domains_rwsem);
 	down_write(&iopt->iova_rwsem);
-	WARN_ON(xa_erase(&iopt->access_list, access->iopt_access_list_id) !=
-		access);
+	WARN_ON(xa_erase(&iopt->access_list, iopt_access_list_id) != access);
 	WARN_ON(iopt_calculate_iova_alignment(iopt));
 	up_write(&iopt->iova_rwsem);
 	up_write(&iopt->domains_rwsem);
diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h
index dba730129b8c..8ba786bc95ff 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h
@@ -323,7 +323,8 @@ struct iommufd_access {
 
 int iopt_add_access(struct io_pagetable *iopt, struct iommufd_access *access);
 void iopt_remove_access(struct io_pagetable *iopt,
-			struct iommufd_access *access);
+			struct iommufd_access *access,
+			u32 iopt_access_list_id);
 void iommufd_access_destroy_object(struct iommufd_object *obj);
 
 #ifdef CONFIG_IOMMUFD_TEST
-- 
2.41.0