i40e/i40evf: Break up xmit_descriptor_count from maybe_stop_tx

In an upcoming patch I would like to have access to the descriptor count
used for the data portion of the frame.  For this reason I am splitting up
the descriptor count function from the function that stops the ring.

Also in order to try and reduce unnecessary duplication of code I am moving
the slow-path portions of the code out of being inline calls so that we can
just jump to them and process them instead of having to build them into
each function that calls them.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 12 insertions, 2 deletions

diff --git a/drivers/net/ethernet/intel/i40e/i40e_fcoe.c b/drivers/net/ethernet/intel/i40e/i40e_fcoe.c
index 7c66ce416ec7..518d72ea1059 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_fcoe.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_fcoe.c
@@ -1359,16 +1359,26 @@ static netdev_tx_t i40e_fcoe_xmit_frame(struct sk_buff *skb,
 	struct i40e_ring *tx_ring = vsi->tx_rings[skb->queue_mapping];
 	struct i40e_tx_buffer *first;
 	u32 tx_flags = 0;
+	int fso, count;
 	u8 hdr_len = 0;
 	u8 sof = 0;
 	u8 eof = 0;
-	int fso;
 
 	if (i40e_fcoe_set_skb_header(skb))
 		goto out_drop;
 
-	if (!i40e_xmit_descriptor_count(skb, tx_ring))
+	count = i40e_xmit_descriptor_count(skb);
+
+	/* need: 1 descriptor per page * PAGE_SIZE/I40E_MAX_DATA_PER_TXD,
+	 *       + 1 desc for skb_head_len/I40E_MAX_DATA_PER_TXD,
+	 *       + 4 desc gap to avoid the cache line where head is,
+	 *       + 1 desc for context descriptor,
+	 * otherwise try next time
+	 */
+	if (i40e_maybe_stop_tx(tx_ring, count + 4 + 1)) {
+		tx_ring->tx_stats.tx_busy++;
 		return NETDEV_TX_BUSY;
+	}
 
 	/* prepare the xmit flags */
 	if (i40e_tx_prepare_vlan_flags(skb, tx_ring, &tx_flags))