IB/mlx5: Implements disassociate_ucontext API

Implements the IB core disassociate_ucontext API.
The driver detaches the HW resources for a given user context to
prevent a dependency between application termination and device
disconnect. This is done by managing the VMAs that were mapped
to the HW bars such as doorbell and blueflame. When need to detach,
remap them to an arbitrary kernel page returned by the zap API.

Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
index 7ac4647..391588e 100644
--- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
+++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
@@ -105,6 +105,11 @@
 	MLX5_CQE_VERSION_V1,
 };
 
+struct mlx5_ib_vma_private_data {
+	struct list_head list;
+	struct vm_area_struct *vma;
+};
+
 struct mlx5_ib_ucontext {
 	struct ib_ucontext	ibucontext;
 	struct list_head	db_page_list;
@@ -116,6 +121,7 @@
 	u8			cqe_version;
 	/* Transport Domain number */
 	u32			tdn;
+	struct list_head	vma_private_list;
 };
 
 static inline struct mlx5_ib_ucontext *to_mucontext(struct ib_ucontext *ibucontext)