IB/core: Add user MR re-registration support

Memory re-registration is a feature that enables changing the
attributes of a memory region registered by user-space, including PD,
translation (address and length) and access flags.

Add the required support in uverbs and the kernel verbs API.

Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 7ccef34..ed44cc0 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -1097,7 +1097,8 @@
 enum ib_mr_rereg_flags {
 	IB_MR_REREG_TRANS	= 1,
 	IB_MR_REREG_PD		= (1<<1),
-	IB_MR_REREG_ACCESS	= (1<<2)
+	IB_MR_REREG_ACCESS	= (1<<2),
+	IB_MR_REREG_SUPPORTED	= ((IB_MR_REREG_ACCESS << 1) - 1)
 };
 
 /**
@@ -1547,6 +1548,13 @@
 						  u64 virt_addr,
 						  int mr_access_flags,
 						  struct ib_udata *udata);
+	int			   (*rereg_user_mr)(struct ib_mr *mr,
+						    int flags,
+						    u64 start, u64 length,
+						    u64 virt_addr,
+						    int mr_access_flags,
+						    struct ib_pd *pd,
+						    struct ib_udata *udata);
 	int                        (*query_mr)(struct ib_mr *mr,
 					       struct ib_mr_attr *mr_attr);
 	int                        (*dereg_mr)(struct ib_mr *mr);