[SCSI] scsi_transport_iscsi: added support for host event

Added support to post kernel host event to application using
netlink interface.

Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/include/scsi/iscsi_if.h b/include/scsi/iscsi_if.h
index e49b7c8..3aac991 100644
--- a/include/scsi/iscsi_if.h
+++ b/include/scsi/iscsi_if.h
@@ -72,6 +72,7 @@
 	ISCSI_KEVENT_PATH_REQ		= KEVENT_BASE + 7,
 	ISCSI_KEVENT_IF_DOWN		= KEVENT_BASE + 8,
 	ISCSI_KEVENT_CONN_LOGIN_STATE   = KEVENT_BASE + 9,
+	ISCSI_KEVENT_HOST_EVENT		= KEVENT_BASE + 10,
 };
 
 enum iscsi_tgt_dscvr {
@@ -80,6 +81,13 @@
 	ISCSI_TGT_DSCVR_SLP		= 3,
 };
 
+enum iscsi_host_event_code {
+	ISCSI_EVENT_LINKUP		= 1,
+	ISCSI_EVENT_LINKDOWN,
+	/* must always be last */
+	ISCSI_EVENT_MAX,
+};
+
 struct iscsi_uevent {
 	uint32_t type; /* k/u events type */
 	uint32_t iferror; /* carries interface or resource errors */
@@ -222,6 +230,11 @@
 		struct msg_notify_if_down {
 			uint32_t	host_no;
 		} notify_if_down;
+		struct msg_host_event {
+			uint32_t	host_no;
+			uint32_t	data_size;
+			enum iscsi_host_event_code code;
+		} host_event;
 	} r;
 } __attribute__ ((aligned (sizeof(uint64_t))));