RDMA/core: export ib_get_cached_port_state

Export function for rdma_cm, patch for rdma_cm to follow.
Signed-off-by: Jack Wang <jinpu.wang@profitbricks.com>
Reviewed-by: Michael Wang <yun.wang@profitbricks.com>
Acked-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/core/cache.c

@@ -1021,6 +1021,24 @@ int ib_get_cached_lmc(struct ib_device *device,
 }
 EXPORT_SYMBOL(ib_get_cached_lmc);
 
+int ib_get_cached_port_state(struct ib_device   *device,
+			     u8                  port_num,
+			     enum ib_port_state *port_state)
+{
+	unsigned long flags;
+	int ret = 0;
+
+	if (port_num < rdma_start_port(device) || port_num > rdma_end_port(device))
+		return -EINVAL;
+
+	read_lock_irqsave(&device->cache.lock, flags);
+	*port_state = device->cache.port_state_cache[port_num - rdma_start_port(device)];
+	read_unlock_irqrestore(&device->cache.lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL(ib_get_cached_port_state);
+
 static void ib_cache_update(struct ib_device *device,
 			    u8                port)
 {

include/rdma/ib_cache.h

@@ -165,4 +165,17 @@ int ib_get_cached_lmc(struct ib_device *device,
 		      u8                port_num,
 		      u8                *lmc);
 
+/**
+ * ib_get_cached_port_state - Returns a cached port state table entry
+ * @device: The device to query.
+ * @port_num: The port number of the device to query.
+ * @port_state: port_state for the specified port for that device.
+ *
+ * ib_get_cached_port_state() fetches the specified port_state table entry stored in
+ * the local software cache.
+ */
+int ib_get_cached_port_state(struct ib_device *device,
+			      u8                port_num,
+			      enum ib_port_state *port_active);
+
 #endif /* _IB_CACHE_H */