IB/cm: Fix automatic path migration support

The ib_cm_establish() function is replaced with a more generic
ib_cm_notify().  This routine is used to notify the CM that failover
has occurred, so that future CM messages (LAP, DREQ) reach the remote
CM.  (Currently, we continue to use the original path)  This bumps the
userspace CM ABI.

New alternate path information is captured when a LAP message is sent
or received.  This allows QP attributes to be initialized for the user
when a new path is loaded after failover occurs.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

2 files changed, 16 insertions, 7 deletions

diff --git a/include/rdma/ib_cm.h b/include/rdma/ib_cm.h
index c9b4738be9d6..5c070176d9ab 100644
--- a/include/rdma/ib_cm.h
+++ b/include/rdma/ib_cm.h
@@ -60,6 +60,7 @@ enum ib_cm_state {
 };
 
 enum ib_cm_lap_state {
+        IB_CM_LAP_UNINIT,
         IB_CM_LAP_IDLE,
         IB_CM_LAP_SENT,
         IB_CM_LAP_RCVD,
@@ -443,13 +444,20 @@ int ib_send_cm_drep(struct ib_cm_id *cm_id,
                     u8 private_data_len);
 
 /**
- * ib_cm_establish - Forces a connection state to established.
+ * ib_cm_notify - Notifies the CM of an event reported to the consumer.
  * @cm_id: Connection identifier to transition to established.
+ * @event: Type of event.
  *
- * This routine should be invoked by users who receive messages on a
- * connected QP before an RTU has been received.
+ * This routine should be invoked by users to notify the CM of relevant
+ * communication events.  Events that should be reported to the CM and
+ * when to report them are:
+ *
+ * IB_EVENT_COMM_EST - Used when a message is received on a connected
+ *    QP before an RTU has been received.
+ * IB_EVENT_PATH_MIG - Notifies the CM that the connection has failed over
+ *   to the alternate path.
  */
-int ib_cm_establish(struct ib_cm_id *cm_id);
+int ib_cm_notify(struct ib_cm_id *cm_id, enum ib_event_type event);
 
 /**
  * ib_send_cm_rej - Sends a connection rejection message to the
diff --git a/include/rdma/ib_user_cm.h b/include/rdma/ib_user_cm.h
index 066c20b7cdfb..37650afb982c 100644
--- a/include/rdma/ib_user_cm.h
+++ b/include/rdma/ib_user_cm.h
@@ -38,7 +38,7 @@
 
 #include <rdma/ib_user_sa.h>
 
-#define IB_USER_CM_ABI_VERSION 4
+#define IB_USER_CM_ABI_VERSION 5
 
 enum {
         IB_USER_CM_CMD_CREATE_ID,
@@ -46,7 +46,7 @@ enum {
         IB_USER_CM_CMD_ATTR_ID,
 
         IB_USER_CM_CMD_LISTEN,
-        IB_USER_CM_CMD_ESTABLISH,
+        IB_USER_CM_CMD_NOTIFY,
 
         IB_USER_CM_CMD_SEND_REQ,
         IB_USER_CM_CMD_SEND_REP,
@@ -117,8 +117,9 @@ struct ib_ucm_listen {
         __u32 reserved;
 };
 
-struct ib_ucm_establish {
+struct ib_ucm_notify {
         __u32 id;
+        __u32 event;
 };
 
 struct ib_ucm_private_data {