IB/uverbs: Implement memory windows support in uverbs

The existing user/kernel uverbs API has IB_USER_VERBS_CMD_ALLOC/DEALLOC_MW.
Implement these calls, along with destroying user memory windows during
process cleanup.

Signed-off-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Shani Michaeli <shanim@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/include/uapi/rdma/ib_user_verbs.h b/include/uapi/rdma/ib_user_verbs.h
index 81aba3a..805711e 100644
--- a/include/uapi/rdma/ib_user_verbs.h
+++ b/include/uapi/rdma/ib_user_verbs.h
@@ -261,6 +261,22 @@
 	__u32 mr_handle;
 };
 
+struct ib_uverbs_alloc_mw {
+	__u64 response;
+	__u32 pd_handle;
+	__u8  mw_type;
+	__u8  reserved[3];
+};
+
+struct ib_uverbs_alloc_mw_resp {
+	__u32 mw_handle;
+	__u32 rkey;
+};
+
+struct ib_uverbs_dealloc_mw {
+	__u32 mw_handle;
+};
+
 struct ib_uverbs_create_comp_channel {
 	__u64 response;
 };