sfc: Move TX queue core queue mapping into tx.c

efx_hard_start_xmit() needs to implement a mapping which is the
inverse of tx_queue::core_txq.  Move the initialisation of
tx_queue::core_txq next to efx_hard_start_xmit() to make the
connection more obvious.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

drivers/net/sfc/efx.c

@@ -1910,10 +1910,8 @@ static int efx_register_netdev(struct efx_nic *efx)
 
 	efx_for_each_channel(channel, efx) {
 		struct efx_tx_queue *tx_queue;
-		efx_for_each_channel_tx_queue(tx_queue, channel) {
-			tx_queue->core_txq = netdev_get_tx_queue(
-				efx->net_dev, tx_queue->queue / EFX_TXQ_TYPES);
-		}
+		efx_for_each_channel_tx_queue(tx_queue, channel)
+			efx_init_tx_queue_core_txq(tx_queue);
 	}
 
 	/* Always start with carrier off; PHY events will detect the link */

drivers/net/sfc/efx.h

@@ -29,6 +29,7 @@
 extern int efx_probe_tx_queue(struct efx_tx_queue *tx_queue);
 extern void efx_remove_tx_queue(struct efx_tx_queue *tx_queue);
 extern void efx_init_tx_queue(struct efx_tx_queue *tx_queue);
+extern void efx_init_tx_queue_core_txq(struct efx_tx_queue *tx_queue);
 extern void efx_fini_tx_queue(struct efx_tx_queue *tx_queue);
 extern void efx_release_tx_buffers(struct efx_tx_queue *tx_queue);
 extern netdev_tx_t

drivers/net/sfc/tx.c

@@ -347,6 +347,13 @@ netdev_tx_t efx_hard_start_xmit(struct sk_buff *skb,
 	return efx_enqueue_skb(tx_queue, skb);
 }
 
+void efx_init_tx_queue_core_txq(struct efx_tx_queue *tx_queue)
+{
+	/* Must be inverse of queue lookup in efx_hard_start_xmit() */
+	tx_queue->core_txq = netdev_get_tx_queue(
+		tx_queue->efx->net_dev, tx_queue->queue / EFX_TXQ_TYPES);
+}
+
 void efx_xmit_done(struct efx_tx_queue *tx_queue, unsigned int index)
 {
 	unsigned fill_level;