qed: Add ll2 option for dropping a tx packet

The option of sending a packet on the ll2 and dropping it exists in
hardware and was not used until now, thus not exposed.
The iWARP unaligned MPA flow requires this functionality for
flushing the tx queue.
Signed-off-by: NMichal Kalderon <Michal.Kalderon@cavium.com>
Signed-off-by: NAriel Elior <Ariel.Elior@cavium.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/qlogic/qed/qed_ll2.c

@@ -1597,8 +1597,20 @@ qed_ll2_prepare_tx_packet_set_bd(struct qed_hwfn *p_hwfn,
 	roce_flavor = (pkt->qed_roce_flavor == QED_LL2_ROCE) ? CORE_ROCE
 							     : CORE_RROCE;
 
-	tx_dest = (pkt->tx_dest == QED_LL2_TX_DEST_NW) ? CORE_TX_DEST_NW
-						       : CORE_TX_DEST_LB;
+	switch (pkt->tx_dest) {
+	case QED_LL2_TX_DEST_NW:
+		tx_dest = CORE_TX_DEST_NW;
+		break;
+	case QED_LL2_TX_DEST_LB:
+		tx_dest = CORE_TX_DEST_LB;
+		break;
+	case QED_LL2_TX_DEST_DROP:
+		tx_dest = CORE_TX_DEST_DROP;
+		break;
+	default:
+		tx_dest = CORE_TX_DEST_LB;
+		break;
+	}
 
 	start_bd = (struct core_tx_bd *)qed_chain_produce(p_tx_chain);
 	start_bd->nw_vlan_or_lb_echo = cpu_to_le16(pkt->vlan);

include/linux/qed/qed_ll2_if.h

@@ -64,6 +64,7 @@ enum qed_ll2_roce_flavor_type {
 enum qed_ll2_tx_dest {
 	QED_LL2_TX_DEST_NW, /* Light L2 TX Destination to the Network */
 	QED_LL2_TX_DEST_LB, /* Light L2 TX Destination to the Loopback */
+	QED_LL2_TX_DEST_DROP, /* Light L2 Drop the TX packet */
 	QED_LL2_TX_DEST_MAX
 };