An IOMMU driver that allocated a vIOMMU may want to revert the allocation,
if it encounters an internal error after the allocation. So, there needs a
destroy helper for drivers to use.

Move iommufd_object_abort() to the driver.c file and the public header, to
introduce common iommufd_struct_destroy() helper that will abort all kinds
of driver structures, not confined to iommufd_viommu but also the new ones
being added by the following patches.

Signed-off-by: Nicolin Chen <nicol...@nvidia.com>
---
 drivers/iommu/iommufd/iommufd_private.h |  1 -
 include/linux/iommufd.h                 | 15 +++++++++++++++
 drivers/iommu/iommufd/driver.c          | 14 ++++++++++++++
 drivers/iommu/iommufd/main.c            | 13 -------------
 4 files changed, 29 insertions(+), 14 deletions(-)

diff --git a/drivers/iommu/iommufd/iommufd_private.h 
b/drivers/iommu/iommufd/iommufd_private.h
index 80e8c76d25f2..51f1b3938023 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h
@@ -180,7 +180,6 @@ static inline void iommufd_put_object(struct iommufd_ctx 
*ictx,
                wake_up_interruptible_all(&ictx->destroy_wait);
 }
 
-void iommufd_object_abort(struct iommufd_ctx *ictx, struct iommufd_object 
*obj);
 void iommufd_object_abort_and_destroy(struct iommufd_ctx *ictx,
                                      struct iommufd_object *obj);
 void iommufd_object_finalize(struct iommufd_ctx *ictx,
diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h
index 34b6e6ca4bfa..999498ddab75 100644
--- a/include/linux/iommufd.h
+++ b/include/linux/iommufd.h
@@ -192,6 +192,7 @@ static inline int iommufd_vfio_compat_set_no_iommu(struct 
iommufd_ctx *ictx)
 struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx,
                                             size_t size,
                                             enum iommufd_object_type type);
+void iommufd_object_abort(struct iommufd_ctx *ictx, struct iommufd_object 
*obj);
 struct device *iommufd_viommu_find_dev(struct iommufd_viommu *viommu,
                                       unsigned long vdev_id);
 int iommufd_viommu_get_vdev_id(struct iommufd_viommu *viommu,
@@ -207,6 +208,11 @@ _iommufd_object_alloc(struct iommufd_ctx *ictx, size_t 
size,
        return ERR_PTR(-EOPNOTSUPP);
 }
 
+static inline void iommufd_object_abort(struct iommufd_ctx *ictx,
+                                       struct iommufd_object *obj)
+{
+}
+
 static inline struct device *
 iommufd_viommu_find_dev(struct iommufd_viommu *viommu, unsigned long vdev_id)
 {
@@ -245,4 +251,13 @@ static inline int iommufd_viommu_report_event(struct 
iommufd_viommu *viommu,
                        ret->member.ops = viommu_ops;                          \
                ret;                                                           \
        })
+
+/* Helper for IOMMU driver to destroy structures created by allocators above */
+#define iommufd_struct_destroy(ictx, drv_struct, member)                       
\
+       ({                                                                     \
+               static_assert(__same_type(struct iommufd_object,               \
+                                         drv_struct->member.obj));            \
+               static_assert(offsetof(typeof(*drv_struct), member.obj) == 0); \
+               iommufd_object_abort(ictx, &drv_struct->member.obj);           \
+       })
 #endif
diff --git a/drivers/iommu/iommufd/driver.c b/drivers/iommu/iommufd/driver.c
index 922cd1fe7ec2..7980a09761c2 100644
--- a/drivers/iommu/iommufd/driver.c
+++ b/drivers/iommu/iommufd/driver.c
@@ -36,6 +36,20 @@ struct iommufd_object *_iommufd_object_alloc(struct 
iommufd_ctx *ictx,
 }
 EXPORT_SYMBOL_NS_GPL(_iommufd_object_alloc, "IOMMUFD");
 
+/* Undo _iommufd_object_alloc() if iommufd_object_finalize() was not called */
+void iommufd_object_abort(struct iommufd_ctx *ictx, struct iommufd_object *obj)
+{
+       XA_STATE(xas, &ictx->objects, obj->id);
+       void *old;
+
+       xa_lock(&ictx->objects);
+       old = xas_store(&xas, NULL);
+       xa_unlock(&ictx->objects);
+       WARN_ON(old != XA_ZERO_ENTRY);
+       kfree(obj);
+}
+EXPORT_SYMBOL_NS_GPL(iommufd_object_abort, "IOMMUFD");
+
 /* Caller should xa_lock(&viommu->vdevs) to protect the return value */
 struct device *iommufd_viommu_find_dev(struct iommufd_viommu *viommu,
                                       unsigned long vdev_id)
diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c
index 3df468f64e7d..2b9ee9b4a424 100644
--- a/drivers/iommu/iommufd/main.c
+++ b/drivers/iommu/iommufd/main.c
@@ -51,19 +51,6 @@ void iommufd_object_finalize(struct iommufd_ctx *ictx,
        WARN_ON(old != XA_ZERO_ENTRY);
 }
 
-/* Undo _iommufd_object_alloc() if iommufd_object_finalize() was not called */
-void iommufd_object_abort(struct iommufd_ctx *ictx, struct iommufd_object *obj)
-{
-       XA_STATE(xas, &ictx->objects, obj->id);
-       void *old;
-
-       xa_lock(&ictx->objects);
-       old = xas_store(&xas, NULL);
-       xa_unlock(&ictx->objects);
-       WARN_ON(old != XA_ZERO_ENTRY);
-       kfree(obj);
-}
-
 /*
  * Abort an object that has been fully initialized and needs destroy, but has
  * not been finalized.
-- 
2.43.0


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