netdevice: move netdev_cap_txqueue for shared usage to header

In order to allow users to invoke netdev_cap_txqueue, it needs to
be moved into netdevice.h header file. While at it, also add kernel
doc header to document the API.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 21 insertions, 12 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 1de9c136b066..e8eeebd49a98 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2279,6 +2279,26 @@ static inline void netdev_reset_queue(struct net_device *dev_queue)
 }
 
 /**
+ *      netdev_cap_txqueue - check if selected tx queue exceeds device queues
+ *      @dev: network device
+ *      @queue_index: given tx queue index
+ *
+ *      Returns 0 if given tx queue index >= number of device tx queues,
+ *      otherwise returns the originally passed tx queue index.
+ */
+static inline u16 netdev_cap_txqueue(struct net_device *dev, u16 queue_index)
+{
+        if (unlikely(queue_index >= dev->real_num_tx_queues)) {
+                net_warn_ratelimited("%s selects TX queue %d, but real number of TX queues is %d\n",
+                                     dev->name, queue_index,
+                                     dev->real_num_tx_queues);
+                return 0;
+        }
+
+        return queue_index;
+}
+
+/**
  *      netif_running - test if up
  *      @dev: network device
  *
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 75fe83f590ea..e29e810663d7 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -323,17 +323,6 @@ u32 __skb_get_poff(const struct sk_buff *skb)
         return poff;
 }
 
-static inline u16 dev_cap_txqueue(struct net_device *dev, u16 queue_index)
-{
-        if (unlikely(queue_index >= dev->real_num_tx_queues)) {
-                net_warn_ratelimited("%s selects TX queue %d, but real number of TX queues is %d\n",
-                                     dev->name, queue_index,
-                                     dev->real_num_tx_queues);
-                return 0;
-        }
-        return queue_index;
-}
-
 static inline int get_xps_queue(struct net_device *dev, struct sk_buff *skb)
 {
 #ifdef CONFIG_XPS
@@ -408,7 +397,7 @@ struct netdev_queue *netdev_pick_tx(struct net_device *dev,
                         queue_index = __netdev_pick_tx(dev, skb);
 
                 if (!accel_priv)
-                        queue_index = dev_cap_txqueue(dev, queue_index);
+                        queue_index = netdev_cap_txqueue(dev, queue_index);
         }
 
         skb_set_queue_mapping(skb, queue_index);