net: ena: add functions for handling Low Latency Queues in ena_netdev

BugLink: http://bugs.launchpad.net/bugs/1798182

This patch includes all code changes necessary in ena_netdev to enable
packet sending via the LLQ placemnt mode.
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 38005ca8 linux-next)
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Acked-by: Khalid Elmously <khalid.elmously@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

drivers/net/ethernet/amazon/ena/ena_ethtool.c

@@ -81,6 +81,7 @@ static const struct ena_stats ena_stats_tx_strings[] = {
 	ENA_STAT_TX_ENTRY(doorbells),
 	ENA_STAT_TX_ENTRY(prepare_ctx_err),
 	ENA_STAT_TX_ENTRY(bad_req_id),
+	ENA_STAT_TX_ENTRY(llq_buffer_copy),
 	ENA_STAT_TX_ENTRY(missed_tx),
 };
 

drivers/net/ethernet/amazon/ena/ena_netdev.h

@@ -148,6 +148,9 @@ struct ena_tx_buffer {
 	/* num of buffers used by this skb */
 	u32 num_of_bufs;
 
+	/* Indicate if bufs[0] map the linear data of the skb. */
+	u8 map_linear_data;
+
 	/* Used for detect missing tx packets to limit the number of prints */
 	u32 print_once;
 	/* Save the last jiffies to detect missing tx packets
@@ -183,6 +186,7 @@ struct ena_stats_tx {
 	u64 tx_poll;
 	u64 doorbells;
 	u64 bad_req_id;
+	u64 llq_buffer_copy;
 	u64 missed_tx;
 };
 
@@ -254,6 +258,8 @@ struct ena_ring {
 		struct ena_stats_tx tx_stats;
 		struct ena_stats_rx rx_stats;
 	};
+
+	u8 *push_buf_intermediate_buf;
 	int empty_rx_queue;
 } ____cacheline_aligned;