Merge branch 'sfc-Add-XDP-support'

Charles McLachlan says:

====================
sfc: Add XDP support

Supply the XDP callbacks in netdevice ops that enable lower level processing
of XDP frames.

Changes in v4:
- Handle the failure to send some frames in efx_xdp_tx_buffers() properly.

Changes in v3:
- Fix a BUG_ON when trying to allocate piobufs to xdp queues.
- Add a missed trace_xdp_exception.

Changes in v2:
- Use of xdp_return_frame_rx_napi() in tx.c
- Addition of xdp_rxq_info_valid and xdp_rxq_info_failed to track when
  xdp_rxq_info failures occur.
- Renaming of rc to err and more use of unlikely().
- Cut some duplicated code and fix an array overrun.
- Actually increment n_rx_xdp_tx when packets are transmitted.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/sfc/ef10.c

@@ -946,8 +946,10 @@ static int efx_ef10_link_piobufs(struct efx_nic *efx)
 		/* Extra channels, even those with TXQs (PTP), do not require
 		 * PIO resources.
 		 */
-		if (!channel->type->want_pio)
+		if (!channel->type->want_pio ||
+		    channel->channel >= efx->xdp_channel_offset)
 			continue;
+
 		efx_for_each_channel_tx_queue(tx_queue, channel) {
 			/* We assign the PIO buffers to queues in
 			 * reverse order to allow for the following
@@ -1296,8 +1298,9 @@ static int efx_ef10_dimension_resources(struct efx_nic *efx)
 	int rc;
 
 	channel_vis = max(efx->n_channels,
-			  (efx->n_tx_channels + efx->n_extra_tx_channels) *
-			  EFX_TXQ_TYPES);
+			  ((efx->n_tx_channels + efx->n_extra_tx_channels) *
+			   EFX_TXQ_TYPES) +
+			   efx->n_xdp_channels * efx->xdp_tx_per_channel);
 
 #ifdef EFX_USE_PIO
 	/* Try to allocate PIO buffers if wanted and if the full
@@ -2434,11 +2437,12 @@ static void efx_ef10_tx_init(struct efx_tx_queue *tx_queue)
 	/* TSOv2 is a limited resource that can only be configured on a limited
 	 * number of queues. TSO without checksum offload is not really a thing,
 	 * so we only enable it for those queues.
-	 * TSOv2 cannot be used with Hardware timestamping.
+	 * TSOv2 cannot be used with Hardware timestamping, and is never needed
+	 * for XDP tx.
 	 */
 	if (csum_offload && (nic_data->datapath_caps2 &
 			(1 << MC_CMD_GET_CAPABILITIES_V2_OUT_TX_TSO_V2_LBN)) &&
-	    !tx_queue->timestamping) {
+	    !tx_queue->timestamping && !tx_queue->xdp_tx) {
 		tso_v2 = true;
 		netif_dbg(efx, hw, efx->net_dev, "Using TSOv2 for channel %u\n",
 				channel->channel);