i40e: add support for XDP_TX action

This patch adds proper XDP_TX action support. For each Tx ring, an
additional XDP Tx ring is allocated and setup. This version does the
DMA mapping in the fast-path, which will penalize performance for
IOMMU enabled systems. Further, debugfs support is not wired up for
the XDP Tx rings.
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e.h

@@ -629,6 +629,7 @@ struct i40e_vsi {
 	/* These are containers of ring pointers, allocated at run-time */
 	struct i40e_ring **rx_rings;
 	struct i40e_ring **tx_rings;
+	struct i40e_ring **xdp_rings; /* XDP Tx rings */
 
 	u32  active_filters;
 	u32  promisc_threshold;

drivers/net/ethernet/intel/i40e/i40e_ethtool.c

@@ -1299,6 +1299,17 @@ static void i40e_get_ringparam(struct net_device *netdev,
 	ring->rx_jumbo_pending = 0;
 }
 
+static bool i40e_active_tx_ring_index(struct i40e_vsi *vsi, u16 index)
+{
+	if (i40e_enabled_xdp_vsi(vsi)) {
+		return index < vsi->num_queue_pairs ||
+			(index >= vsi->alloc_queue_pairs &&
+			 index < vsi->alloc_queue_pairs + vsi->num_queue_pairs);
+	}
+
+	return index < vsi->num_queue_pairs;
+}
+
 static int i40e_set_ringparam(struct net_device *netdev,
 			      struct ethtool_ringparam *ring)
 {
@@ -1308,6 +1319,7 @@ static int i40e_set_ringparam(struct net_device *netdev,
 	struct i40e_vsi *vsi = np->vsi;
 	struct i40e_pf *pf = vsi->back;
 	u32 new_rx_count, new_tx_count;
+	u16 tx_alloc_queue_pairs;
 	int timeout = 50;
 	int i, err = 0;
 
@@ -1345,6 +1357,8 @@ static int i40e_set_ringparam(struct net_device *netdev,
 		for (i = 0; i < vsi->num_queue_pairs; i++) {
 			vsi->tx_rings[i]->count = new_tx_count;
 			vsi->rx_rings[i]->count = new_rx_count;
+			if (i40e_enabled_xdp_vsi(vsi))
+				vsi->xdp_rings[i]->count = new_tx_count;
 		}
 		goto done;
 	}
@@ -1354,20 +1368,24 @@ static int i40e_set_ringparam(struct net_device *netdev,
 	 * to the Tx and Rx ring structs.
 	 */
 
-	/* alloc updated Tx resources */
+	/* alloc updated Tx and XDP Tx resources */
+	tx_alloc_queue_pairs = vsi->alloc_queue_pairs *
+			       (i40e_enabled_xdp_vsi(vsi) ? 2 : 1);
 	if (new_tx_count != vsi->tx_rings[0]->count) {
 		netdev_info(netdev,
 			    "Changing Tx descriptor count from %d to %d.\n",
 			    vsi->tx_rings[0]->count, new_tx_count);
-		tx_rings = kcalloc(vsi->alloc_queue_pairs,
+		tx_rings = kcalloc(tx_alloc_queue_pairs,
 				   sizeof(struct i40e_ring), GFP_KERNEL);
 		if (!tx_rings) {
 			err = -ENOMEM;
 			goto done;
 		}
 
-		for (i = 0; i < vsi->num_queue_pairs; i++) {
-			/* clone ring and setup updated count */
+		for (i = 0; i < tx_alloc_queue_pairs; i++) {
+			if (!i40e_active_tx_ring_index(vsi, i))
+				continue;
+
 			tx_rings[i] = *vsi->tx_rings[i];
 			tx_rings[i].count = new_tx_count;
 			/* the desc and bi pointers will be reallocated in the
@@ -1379,6 +1397,8 @@ static int i40e_set_ringparam(struct net_device *netdev,
 			if (err) {
 				while (i) {
 					i--;
+					if (!i40e_active_tx_ring_index(vsi, i))
+						continue;
 					i40e_free_tx_resources(&tx_rings[i]);
 				}
 				kfree(tx_rings);
@@ -1446,9 +1466,11 @@ static int i40e_set_ringparam(struct net_device *netdev,
 	i40e_down(vsi);
 
 	if (tx_rings) {
-		for (i = 0; i < vsi->num_queue_pairs; i++) {
-			i40e_free_tx_resources(vsi->tx_rings[i]);
-			*vsi->tx_rings[i] = tx_rings[i];
+		for (i = 0; i < tx_alloc_queue_pairs; i++) {
+			if (i40e_active_tx_ring_index(vsi, i)) {
+				i40e_free_tx_resources(vsi->tx_rings[i]);
+				*vsi->tx_rings[i] = tx_rings[i];
+			}
 		}
 		kfree(tx_rings);
 		tx_rings = NULL;
@@ -1479,8 +1501,10 @@ static int i40e_set_ringparam(struct net_device *netdev,
 free_tx:
 	/* error cleanup if the Rx allocations failed after getting Tx */
 	if (tx_rings) {
-		for (i = 0; i < vsi->num_queue_pairs; i++)
-			i40e_free_tx_resources(&tx_rings[i]);
+		for (i = 0; i < tx_alloc_queue_pairs; i++) {
+			if (i40e_active_tx_ring_index(vsi, i))
+				i40e_free_tx_resources(vsi->tx_rings[i]);
+		}
 		kfree(tx_rings);
 		tx_rings = NULL;
 	}

drivers/net/ethernet/intel/i40e/i40e_main.c

@@ -407,6 +407,27 @@ struct rtnl_link_stats64 *i40e_get_vsi_stats_struct(struct i40e_vsi *vsi)
 	return &vsi->net_stats;
 }
 
+/**
+ * i40e_get_netdev_stats_struct_tx - populate stats from a Tx ring
+ * @ring: Tx ring to get statistics from
+ * @stats: statistics entry to be updated
+ **/
+static void i40e_get_netdev_stats_struct_tx(struct i40e_ring *ring,
+					    struct rtnl_link_stats64 *stats)
+{
+	u64 bytes, packets;
+	unsigned int start;
+
+	do {
+		start = u64_stats_fetch_begin_irq(&ring->syncp);
+		packets = ring->stats.packets;
+		bytes   = ring->stats.bytes;
+	} while (u64_stats_fetch_retry_irq(&ring->syncp, start));
+
+	stats->tx_packets += packets;
+	stats->tx_bytes   += bytes;
+}
+
 /**
  * i40e_get_netdev_stats_struct - Get statistics for netdev interface
  * @netdev: network interface device structure
@@ -437,15 +458,8 @@ static void i40e_get_netdev_stats_struct(struct net_device *netdev,
 		tx_ring = ACCESS_ONCE(vsi->tx_rings[i]);
 		if (!tx_ring)
 			continue;
+		i40e_get_netdev_stats_struct_tx(tx_ring, stats);
 
-		do {
-			start = u64_stats_fetch_begin_irq(&tx_ring->syncp);
-			packets = tx_ring->stats.packets;
-			bytes   = tx_ring->stats.bytes;
-		} while (u64_stats_fetch_retry_irq(&tx_ring->syncp, start));
-
-		stats->tx_packets += packets;
-		stats->tx_bytes   += bytes;
 		rx_ring = &tx_ring[1];
 
 		do {
@@ -456,6 +470,9 @@ static void i40e_get_netdev_stats_struct(struct net_device *netdev,
 
 		stats->rx_packets += packets;
 		stats->rx_bytes   += bytes;
+
+		if (i40e_enabled_xdp_vsi(vsi))
+			i40e_get_netdev_stats_struct_tx(&rx_ring[1], stats);
 	}
 	rcu_read_unlock();
 
@@ -2814,6 +2831,12 @@ static int i40e_vsi_setup_tx_resources(struct i40e_vsi *vsi)
 	for (i = 0; i < vsi->num_queue_pairs && !err; i++)
 		err = i40e_setup_tx_descriptors(vsi->tx_rings[i]);
 
+	if (!i40e_enabled_xdp_vsi(vsi))
+		return err;
+
+	for (i = 0; i < vsi->num_queue_pairs && !err; i++)
+		err = i40e_setup_tx_descriptors(vsi->xdp_rings[i]);
+
 	return err;
 }
 
@@ -2827,12 +2850,17 @@ static void i40e_vsi_free_tx_resources(struct i40e_vsi *vsi)
 {
 	int i;
 
-	if (!vsi->tx_rings)
-		return;
+	if (vsi->tx_rings) {
+		for (i = 0; i < vsi->num_queue_pairs; i++)
+			if (vsi->tx_rings[i] && vsi->tx_rings[i]->desc)
+				i40e_free_tx_resources(vsi->tx_rings[i]);
+	}
 
-	for (i = 0; i < vsi->num_queue_pairs; i++)
-		if (vsi->tx_rings[i] && vsi->tx_rings[i]->desc)
-			i40e_free_tx_resources(vsi->tx_rings[i]);
+	if (vsi->xdp_rings) {
+		for (i = 0; i < vsi->num_queue_pairs; i++)
+			if (vsi->xdp_rings[i] && vsi->xdp_rings[i]->desc)
+				i40e_free_tx_resources(vsi->xdp_rings[i]);
+	}
 }
 
 /**
@@ -3093,6 +3121,12 @@ static int i40e_vsi_configure_tx(struct i40e_vsi *vsi)
 	for (i = 0; (i < vsi->num_queue_pairs) && !err; i++)
 		err = i40e_configure_tx_ring(vsi->tx_rings[i]);
 
+	if (!i40e_enabled_xdp_vsi(vsi))
+		return err;
+
+	for (i = 0; (i < vsi->num_queue_pairs) && !err; i++)
+		err = i40e_configure_tx_ring(vsi->xdp_rings[i]);
+
 	return err;
 }
 
@@ -3237,6 +3271,7 @@ static int i40e_vsi_configure(struct i40e_vsi *vsi)
  **/
 static void i40e_vsi_configure_msix(struct i40e_vsi *vsi)
 {
+	bool has_xdp = i40e_enabled_xdp_vsi(vsi);
 	struct i40e_pf *pf = vsi->back;
 	struct i40e_hw *hw = &pf->hw;
 	u16 vector;
@@ -3267,28 +3302,40 @@ static void i40e_vsi_configure_msix(struct i40e_vsi *vsi)
 		/* Linked list for the queuepairs assigned to this vector */
 		wr32(hw, I40E_PFINT_LNKLSTN(vector - 1), qp);
 		for (q = 0; q < q_vector->num_ringpairs; q++) {
+			u32 nextqp = has_xdp ? qp + vsi->alloc_queue_pairs : qp;
 			u32 val;
 
 			val = I40E_QINT_RQCTL_CAUSE_ENA_MASK |
-			      (I40E_RX_ITR << I40E_QINT_RQCTL_ITR_INDX_SHIFT)  |
-			      (vector      << I40E_QINT_RQCTL_MSIX_INDX_SHIFT) |
-			      (qp          << I40E_QINT_RQCTL_NEXTQ_INDX_SHIFT)|
-			      (I40E_QUEUE_TYPE_TX
-				      << I40E_QINT_RQCTL_NEXTQ_TYPE_SHIFT);
+			      (I40E_RX_ITR << I40E_QINT_RQCTL_ITR_INDX_SHIFT) |
+			      (vector << I40E_QINT_RQCTL_MSIX_INDX_SHIFT) |
+			      (nextqp << I40E_QINT_RQCTL_NEXTQ_INDX_SHIFT) |
+			      (I40E_QUEUE_TYPE_TX <<
+			       I40E_QINT_RQCTL_NEXTQ_TYPE_SHIFT);
 
 			wr32(hw, I40E_QINT_RQCTL(qp), val);
 
+			if (has_xdp) {
+				val = I40E_QINT_TQCTL_CAUSE_ENA_MASK |
+				      (I40E_TX_ITR << I40E_QINT_TQCTL_ITR_INDX_SHIFT) |
+				      (vector << I40E_QINT_TQCTL_MSIX_INDX_SHIFT) |
+				      (qp << I40E_QINT_TQCTL_NEXTQ_INDX_SHIFT) |
+				      (I40E_QUEUE_TYPE_TX <<
+				       I40E_QINT_TQCTL_NEXTQ_TYPE_SHIFT);
+
+				wr32(hw, I40E_QINT_TQCTL(nextqp), val);
+			}
+
 			val = I40E_QINT_TQCTL_CAUSE_ENA_MASK |
-			      (I40E_TX_ITR << I40E_QINT_TQCTL_ITR_INDX_SHIFT)  |
-			      (vector      << I40E_QINT_TQCTL_MSIX_INDX_SHIFT) |
-			      ((qp+1)      << I40E_QINT_TQCTL_NEXTQ_INDX_SHIFT)|
-			      (I40E_QUEUE_TYPE_RX
-				      << I40E_QINT_TQCTL_NEXTQ_TYPE_SHIFT);
+			      (I40E_TX_ITR << I40E_QINT_TQCTL_ITR_INDX_SHIFT) |
+			      (vector << I40E_QINT_TQCTL_MSIX_INDX_SHIFT) |
+			      ((qp + 1) << I40E_QINT_TQCTL_NEXTQ_INDX_SHIFT) |
+			      (I40E_QUEUE_TYPE_RX <<
+			       I40E_QINT_TQCTL_NEXTQ_TYPE_SHIFT);
 
 			/* Terminate the linked list */
 			if (q == (q_vector->num_ringpairs - 1))
-				val |= (I40E_QUEUE_END_OF_LIST
-					   << I40E_QINT_TQCTL_NEXTQ_INDX_SHIFT);
+				val |= (I40E_QUEUE_END_OF_LIST <<
+					I40E_QINT_TQCTL_NEXTQ_INDX_SHIFT);
 
 			wr32(hw, I40E_QINT_TQCTL(qp), val);
 			qp++;
@@ -3342,6 +3389,7 @@ static void i40e_enable_misc_int_causes(struct i40e_pf *pf)
  **/
 static void i40e_configure_msi_and_legacy(struct i40e_vsi *vsi)
 {
+	u32 nextqp = i40e_enabled_xdp_vsi(vsi) ? vsi->alloc_queue_pairs : 0;
 	struct i40e_q_vector *q_vector = vsi->q_vectors[0];
 	struct i40e_pf *pf = vsi->back;
 	struct i40e_hw *hw = &pf->hw;
@@ -3362,12 +3410,22 @@ static void i40e_configure_msi_and_legacy(struct i40e_vsi *vsi)
 	wr32(hw, I40E_PFINT_LNKLST0, 0);
 
 	/* Associate the queue pair to the vector and enable the queue int */
-	val = I40E_QINT_RQCTL_CAUSE_ENA_MASK		      |
-	      (I40E_RX_ITR << I40E_QINT_RQCTL_ITR_INDX_SHIFT) |
+	val = I40E_QINT_RQCTL_CAUSE_ENA_MASK		       |
+	      (I40E_RX_ITR << I40E_QINT_RQCTL_ITR_INDX_SHIFT)  |
+	      (nextqp	   << I40E_QINT_RQCTL_NEXTQ_INDX_SHIFT)|
 	      (I40E_QUEUE_TYPE_TX << I40E_QINT_TQCTL_NEXTQ_TYPE_SHIFT);
 
 	wr32(hw, I40E_QINT_RQCTL(0), val);
 
+	if (i40e_enabled_xdp_vsi(vsi)) {
+		val = I40E_QINT_TQCTL_CAUSE_ENA_MASK		     |
+		      (I40E_TX_ITR << I40E_QINT_TQCTL_ITR_INDX_SHIFT)|
+		      (I40E_QUEUE_TYPE_TX
+		       << I40E_QINT_TQCTL_NEXTQ_TYPE_SHIFT);
+
+	       wr32(hw, I40E_QINT_TQCTL(nextqp), val);
+	}
+
 	val = I40E_QINT_TQCTL_CAUSE_ENA_MASK		      |
 	      (I40E_TX_ITR << I40E_QINT_TQCTL_ITR_INDX_SHIFT) |
 	      (I40E_QUEUE_END_OF_LIST << I40E_QINT_TQCTL_NEXTQ_INDX_SHIFT);
@@ -3534,6 +3592,9 @@ static void i40e_vsi_disable_irq(struct i40e_vsi *vsi)
 	for (i = 0; i < vsi->num_queue_pairs; i++) {
 		wr32(hw, I40E_QINT_TQCTL(vsi->tx_rings[i]->reg_idx), 0);
 		wr32(hw, I40E_QINT_RQCTL(vsi->rx_rings[i]->reg_idx), 0);
+		if (!i40e_enabled_xdp_vsi(vsi))
+			continue;
+		wr32(hw, I40E_QINT_TQCTL(vsi->xdp_rings[i]->reg_idx), 0);
 	}
 
 	if (pf->flags & I40E_FLAG_MSIX_ENABLED) {
@@ -3836,6 +3897,16 @@ static void i40e_map_vector_to_qp(struct i40e_vsi *vsi, int v_idx, int qp_idx)
 	q_vector->tx.ring = tx_ring;
 	q_vector->tx.count++;
 
+	/* Place XDP Tx ring in the same q_vector ring list as regular Tx */
+	if (i40e_enabled_xdp_vsi(vsi)) {
+		struct i40e_ring *xdp_ring = vsi->xdp_rings[qp_idx];
+
+		xdp_ring->q_vector = q_vector;
+		xdp_ring->next = q_vector->tx.ring;
+		q_vector->tx.ring = xdp_ring;
+		q_vector->tx.count++;
+	}
+
 	rx_ring->q_vector = q_vector;
 	rx_ring->next = q_vector->rx.ring;
 	q_vector->rx.ring = rx_ring;
@@ -4014,6 +4085,33 @@ static void i40e_control_tx_q(struct i40e_pf *pf, int pf_q, bool enable)
 	wr32(hw, I40E_QTX_ENA(pf_q), tx_reg);
 }
 
+/**
+ * i40e_control_wait_tx_q - Start/stop Tx queue and wait for completion
+ * @seid: VSI SEID
+ * @pf: the PF structure
+ * @pf_q: the PF queue to configure
+ * @is_xdp: true if the queue is used for XDP
+ * @enable: start or stop the queue
+ **/
+static int i40e_control_wait_tx_q(int seid, struct i40e_pf *pf, int pf_q,
+				  bool is_xdp, bool enable)
+{
+	int ret;
+
+	i40e_control_tx_q(pf, pf_q, enable);
+
+	/* wait for the change to finish */
+	ret = i40e_pf_txq_wait(pf, pf_q, enable);
+	if (ret) {
+		dev_info(&pf->pdev->dev,
+			 "VSI seid %d %sTx ring %d %sable timeout\n",
+			 seid, (is_xdp ? "XDP " : ""), pf_q,
+			 (enable ? "en" : "dis"));
+	}
+
+	return ret;
+}
+
 /**
  * i40e_vsi_control_tx - Start or stop a VSI's rings
  * @vsi: the VSI being configured
@@ -4026,16 +4124,20 @@ static int i40e_vsi_control_tx(struct i40e_vsi *vsi, bool enable)
 
 	pf_q = vsi->base_queue;
 	for (i = 0; i < vsi->num_queue_pairs; i++, pf_q++) {
-		i40e_control_tx_q(pf, pf_q, enable);
+		ret = i40e_control_wait_tx_q(vsi->seid, pf,
+					     pf_q,
+					     false /*is xdp*/, enable);
+		if (ret)
+			break;
 
-		/* wait for the change to finish */
-		ret = i40e_pf_txq_wait(pf, pf_q, enable);
-		if (ret) {
-			dev_info(&pf->pdev->dev,
-				 "VSI seid %d Tx ring %d %sable timeout\n",
-				 vsi->seid, pf_q, (enable ? "en" : "dis"));
+		if (!i40e_enabled_xdp_vsi(vsi))
+			continue;
+
+		ret = i40e_control_wait_tx_q(vsi->seid, pf,
+					     pf_q + vsi->alloc_queue_pairs,
+					     true /*is xdp*/, enable);
+		if (ret)
 			break;
-		}
 	}
 
 	return ret;
@@ -4547,7 +4649,21 @@ int i40e_vsi_wait_queues_disabled(struct i40e_vsi *vsi)
 				 vsi->seid, pf_q);
 			return ret;
 		}
-		/* Check and wait for the Tx queue */
+
+		if (!i40e_enabled_xdp_vsi(vsi))
+			goto wait_rx;
+
+		/* Check and wait for the XDP Tx queue */
+		ret = i40e_pf_txq_wait(pf, pf_q + vsi->alloc_queue_pairs,
+				       false);
+		if (ret) {
+			dev_info(&pf->pdev->dev,
+				 "VSI seid %d XDP Tx ring %d disable timeout\n",
+				 vsi->seid, pf_q);
+			return ret;
+		}
+wait_rx:
+		/* Check and wait for the Rx queue */
 		ret = i40e_pf_rxq_wait(pf, pf_q, false);
 		if (ret) {
 			dev_info(&pf->pdev->dev,
@@ -5466,6 +5582,8 @@ void i40e_down(struct i40e_vsi *vsi)
 
 	for (i = 0; i < vsi->num_queue_pairs; i++) {
 		i40e_clean_tx_ring(vsi->tx_rings[i]);
+		if (i40e_enabled_xdp_vsi(vsi))
+			i40e_clean_tx_ring(vsi->xdp_rings[i]);
 		i40e_clean_rx_ring(vsi->rx_rings[i]);
 	}
 
@@ -7535,15 +7653,22 @@ static int i40e_set_num_rings_in_vsi(struct i40e_vsi *vsi)
  **/
 static int i40e_vsi_alloc_arrays(struct i40e_vsi *vsi, bool alloc_qvectors)
 {
+	struct i40e_ring **next_rings;
 	int size;
 	int ret = 0;
 
-	/* allocate memory for both Tx and Rx ring pointers */
-	size = sizeof(struct i40e_ring *) * vsi->alloc_queue_pairs * 2;
+	/* allocate memory for both Tx, XDP Tx and Rx ring pointers */
+	size = sizeof(struct i40e_ring *) * vsi->alloc_queue_pairs *
+	       (i40e_enabled_xdp_vsi(vsi) ? 3 : 2);
 	vsi->tx_rings = kzalloc(size, GFP_KERNEL);
 	if (!vsi->tx_rings)
 		return -ENOMEM;
-	vsi->rx_rings = &vsi->tx_rings[vsi->alloc_queue_pairs];
+	next_rings = vsi->tx_rings + vsi->alloc_queue_pairs;
+	if (i40e_enabled_xdp_vsi(vsi)) {
+		vsi->xdp_rings = next_rings;
+		next_rings += vsi->alloc_queue_pairs;
+	}
+	vsi->rx_rings = next_rings;
 
 	if (alloc_qvectors) {
 		/* allocate memory for q_vector pointers */
@@ -7663,6 +7788,7 @@ static void i40e_vsi_free_arrays(struct i40e_vsi *vsi, bool free_qvectors)
 	kfree(vsi->tx_rings);
 	vsi->tx_rings = NULL;
 	vsi->rx_rings = NULL;
+	vsi->xdp_rings = NULL;
 }
 
 /**
@@ -7746,6 +7872,8 @@ static void i40e_vsi_clear_rings(struct i40e_vsi *vsi)
 			kfree_rcu(vsi->tx_rings[i], rcu);
 			vsi->tx_rings[i] = NULL;
 			vsi->rx_rings[i] = NULL;
+			if (vsi->xdp_rings)
+				vsi->xdp_rings[i] = NULL;
 		}
 	}
 }
@@ -7756,43 +7884,61 @@ static void i40e_vsi_clear_rings(struct i40e_vsi *vsi)
  **/
 static int i40e_alloc_rings(struct i40e_vsi *vsi)
 {
-	struct i40e_ring *tx_ring, *rx_ring;
+	int i, qpv = i40e_enabled_xdp_vsi(vsi) ? 3 : 2;
 	struct i40e_pf *pf = vsi->back;
-	int i;
+	struct i40e_ring *ring;
 
 	/* Set basic values in the rings to be used later during open() */
 	for (i = 0; i < vsi->alloc_queue_pairs; i++) {
 		/* allocate space for both Tx and Rx in one shot */
-		tx_ring = kzalloc(sizeof(struct i40e_ring) * 2, GFP_KERNEL);
-		if (!tx_ring)
+		ring = kcalloc(qpv, sizeof(struct i40e_ring), GFP_KERNEL);
+		if (!ring)
 			goto err_out;
 
-		tx_ring->queue_index = i;
-		tx_ring->reg_idx = vsi->base_queue + i;
-		tx_ring->ring_active = false;
-		tx_ring->vsi = vsi;
-		tx_ring->netdev = vsi->netdev;
-		tx_ring->dev = &pf->pdev->dev;
-		tx_ring->count = vsi->num_desc;
-		tx_ring->size = 0;
-		tx_ring->dcb_tc = 0;
+		ring->queue_index = i;
+		ring->reg_idx = vsi->base_queue + i;
+		ring->ring_active = false;
+		ring->vsi = vsi;
+		ring->netdev = vsi->netdev;
+		ring->dev = &pf->pdev->dev;
+		ring->count = vsi->num_desc;
+		ring->size = 0;
+		ring->dcb_tc = 0;
 		if (vsi->back->flags & I40E_FLAG_WB_ON_ITR_CAPABLE)
-			tx_ring->flags = I40E_TXR_FLAGS_WB_ON_ITR;
-		tx_ring->tx_itr_setting = pf->tx_itr_default;
-		vsi->tx_rings[i] = tx_ring;
-
-		rx_ring = &tx_ring[1];
-		rx_ring->queue_index = i;
-		rx_ring->reg_idx = vsi->base_queue + i;
-		rx_ring->ring_active = false;
-		rx_ring->vsi = vsi;
-		rx_ring->netdev = vsi->netdev;
-		rx_ring->dev = &pf->pdev->dev;
-		rx_ring->count = vsi->num_desc;
-		rx_ring->size = 0;
-		rx_ring->dcb_tc = 0;
-		rx_ring->rx_itr_setting = pf->rx_itr_default;
-		vsi->rx_rings[i] = rx_ring;
+			ring->flags = I40E_TXR_FLAGS_WB_ON_ITR;
+		ring->tx_itr_setting = pf->tx_itr_default;
+		vsi->tx_rings[i] = ring++;
+
+		if (!i40e_enabled_xdp_vsi(vsi))
+			goto setup_rx;
+
+		ring->queue_index = vsi->alloc_queue_pairs + i;
+		ring->reg_idx = vsi->base_queue + ring->queue_index;
+		ring->ring_active = false;
+		ring->vsi = vsi;
+		ring->netdev = NULL;
+		ring->dev = &pf->pdev->dev;
+		ring->count = vsi->num_desc;
+		ring->size = 0;
+		ring->dcb_tc = 0;
+		if (vsi->back->flags & I40E_FLAG_WB_ON_ITR_CAPABLE)
+			ring->flags = I40E_TXR_FLAGS_WB_ON_ITR;
+		set_ring_xdp(ring);
+		ring->tx_itr_setting = pf->tx_itr_default;
+		vsi->xdp_rings[i] = ring++;
+
+setup_rx:
+		ring->queue_index = i;
+		ring->reg_idx = vsi->base_queue + i;
+		ring->ring_active = false;
+		ring->vsi = vsi;
+		ring->netdev = vsi->netdev;
+		ring->dev = &pf->pdev->dev;
+		ring->count = vsi->num_desc;
+		ring->size = 0;
+		ring->dcb_tc = 0;
+		ring->rx_itr_setting = pf->rx_itr_default;
+		vsi->rx_rings[i] = ring;
 	}
 
 	return 0;
@@ -9998,6 +10144,7 @@ static int i40e_vsi_setup_vectors(struct i40e_vsi *vsi)
  **/
 static struct i40e_vsi *i40e_vsi_reinit_setup(struct i40e_vsi *vsi)
 {
+	u16 alloc_queue_pairs;
 	struct i40e_pf *pf;
 	u8 enabled_tc;
 	int ret;
@@ -10016,11 +10163,14 @@ static struct i40e_vsi *i40e_vsi_reinit_setup(struct i40e_vsi *vsi)
 	if (ret)
 		goto err_vsi;
 
-	ret = i40e_get_lump(pf, pf->qp_pile, vsi->alloc_queue_pairs, vsi->idx);
+	alloc_queue_pairs = vsi->alloc_queue_pairs *
+			    (i40e_enabled_xdp_vsi(vsi) ? 2 : 1);
+
+	ret = i40e_get_lump(pf, pf->qp_pile, alloc_queue_pairs, vsi->idx);
 	if (ret < 0) {
 		dev_info(&pf->pdev->dev,
 			 "failed to get tracking for %d queues for VSI %d err %d\n",
-			 vsi->alloc_queue_pairs, vsi->seid, ret);
+			 alloc_queue_pairs, vsi->seid, ret);
 		goto err_vsi;
 	}
 	vsi->base_queue = ret;
@@ -10076,6 +10226,7 @@ struct i40e_vsi *i40e_vsi_setup(struct i40e_pf *pf, u8 type,
 {
 	struct i40e_vsi *vsi = NULL;
 	struct i40e_veb *veb = NULL;
+	u16 alloc_queue_pairs;
 	int ret, i;
 	int v_idx;
 
@@ -10163,12 +10314,14 @@ struct i40e_vsi *i40e_vsi_setup(struct i40e_pf *pf, u8 type,
 	else if (type == I40E_VSI_SRIOV)
 		vsi->vf_id = param1;
 	/* assign it some queues */
-	ret = i40e_get_lump(pf, pf->qp_pile, vsi->alloc_queue_pairs,
-				vsi->idx);
+	alloc_queue_pairs = vsi->alloc_queue_pairs *
+			    (i40e_enabled_xdp_vsi(vsi) ? 2 : 1);
+
+	ret = i40e_get_lump(pf, pf->qp_pile, alloc_queue_pairs, vsi->idx);
 	if (ret < 0) {
 		dev_info(&pf->pdev->dev,
 			 "failed to get tracking for %d queues for VSI %d err=%d\n",
-			 vsi->alloc_queue_pairs, vsi->seid, ret);
+			 alloc_queue_pairs, vsi->seid, ret);
 		goto err_vsi;
 	}
 	vsi->base_queue = ret;

drivers/net/ethernet/intel/i40e/i40e_txrx.c

@@ -630,6 +630,8 @@ static void i40e_unmap_and_free_tx_resource(struct i40e_ring *ring,
 	if (tx_buffer->skb) {
 		if (tx_buffer->tx_flags & I40E_TX_FLAGS_FD_SB)
 			kfree(tx_buffer->raw_buf);
+		else if (ring_is_xdp(ring))
+			page_frag_free(tx_buffer->raw_buf);
 		else
 			dev_kfree_skb_any(tx_buffer->skb);
 		if (dma_unmap_len(tx_buffer, len))
@@ -771,8 +773,11 @@ static bool i40e_clean_tx_irq(struct i40e_vsi *vsi,
 		total_bytes += tx_buf->bytecount;
 		total_packets += tx_buf->gso_segs;
 
-		/* free the skb */
-		napi_consume_skb(tx_buf->skb, napi_budget);
+		/* free the skb/XDP data */
+		if (ring_is_xdp(tx_ring))
+			page_frag_free(tx_buf->raw_buf);
+		else
+			napi_consume_skb(tx_buf->skb, napi_budget);
 
 		/* unmap skb header data */
 		dma_unmap_single(tx_ring->dev,
@@ -848,6 +853,9 @@ static bool i40e_clean_tx_irq(struct i40e_vsi *vsi,
 			tx_ring->arm_wb = true;
 	}
 
+	if (ring_is_xdp(tx_ring))
+		return !!budget;
+
 	/* notify netdev of completed buffers */
 	netdev_tx_completed_queue(txring_txq(tx_ring),
 				  total_packets, total_bytes);
@@ -1969,6 +1977,10 @@ static bool i40e_is_non_eop(struct i40e_ring *rx_ring,
 
 #define I40E_XDP_PASS 0
 #define I40E_XDP_CONSUMED 1
+#define I40E_XDP_TX 2
+
+static int i40e_xmit_xdp_ring(struct xdp_buff *xdp,
+			      struct i40e_ring *xdp_ring);
 
 /**
  * i40e_run_xdp - run an XDP program
@@ -1979,6 +1991,7 @@ static struct sk_buff *i40e_run_xdp(struct i40e_ring *rx_ring,
 				    struct xdp_buff *xdp)
 {
 	int result = I40E_XDP_PASS;
+	struct i40e_ring *xdp_ring;
 	struct bpf_prog *xdp_prog;
 	u32 act;
 
@@ -1992,9 +2005,12 @@ static struct sk_buff *i40e_run_xdp(struct i40e_ring *rx_ring,
 	switch (act) {
 	case XDP_PASS:
 		break;
+	case XDP_TX:
+		xdp_ring = rx_ring->vsi->xdp_rings[rx_ring->queue_index];
+		result = i40e_xmit_xdp_ring(xdp, xdp_ring);
+		break;
 	default:
 		bpf_warn_invalid_xdp_action(act);
-	case XDP_TX:
 	case XDP_ABORTED:
 		trace_xdp_exception(rx_ring->netdev, xdp_prog, act);
 		/* fallthrough -- handle aborts by dropping packet */
@@ -2007,6 +2023,27 @@ static struct sk_buff *i40e_run_xdp(struct i40e_ring *rx_ring,
 	return ERR_PTR(-result);
 }
 
+/**
+ * i40e_rx_buffer_flip - adjusted rx_buffer to point to an unused region
+ * @rx_ring: Rx ring
+ * @rx_buffer: Rx buffer to adjust
+ * @size: Size of adjustment
+ **/
+static void i40e_rx_buffer_flip(struct i40e_ring *rx_ring,
+				struct i40e_rx_buffer *rx_buffer,
+				unsigned int size)
+{
+#if (PAGE_SIZE < 8192)
+	unsigned int truesize = i40e_rx_pg_size(rx_ring) / 2;
+
+	rx_buffer->page_offset ^= truesize;
+#else
+	unsigned int truesize = SKB_DATA_ALIGN(i40e_rx_offset(rx_ring) + size);
+
+	rx_buffer->page_offset += truesize;
+#endif
+}
+
 /**
  * i40e_clean_rx_irq - Clean completed descriptors from Rx ring - bounce buf
  * @rx_ring: rx descriptor ring to transact packets on
@@ -2024,7 +2061,7 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget)
 	unsigned int total_rx_bytes = 0, total_rx_packets = 0;
 	struct sk_buff *skb = rx_ring->skb;
 	u16 cleaned_count = I40E_DESC_UNUSED(rx_ring);
-	bool failure = false;
+	bool failure = false, xdp_xmit = false;
 
 	while (likely(total_rx_packets < budget)) {
 		struct i40e_rx_buffer *rx_buffer;
@@ -2081,9 +2118,14 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget)
 		}
 
 		if (IS_ERR(skb)) {
+			if (PTR_ERR(skb) == -I40E_XDP_TX) {
+				xdp_xmit = true;
+				i40e_rx_buffer_flip(rx_ring, rx_buffer, size);
+			} else {
+				rx_buffer->pagecnt_bias++;
+			}
 			total_rx_bytes += size;
 			total_rx_packets++;
-			rx_buffer->pagecnt_bias++;
 		} else if (skb) {
 			i40e_add_rx_frag(rx_ring, rx_buffer, skb, size);
 		} else if (ring_uses_build_skb(rx_ring)) {
@@ -2131,6 +2173,19 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget)
 		total_rx_packets++;
 	}
 
+	if (xdp_xmit) {
+		struct i40e_ring *xdp_ring;
+
+		xdp_ring = rx_ring->vsi->xdp_rings[rx_ring->queue_index];
+
+		/* Force memory writes to complete before letting h/w
+		 * know there are new descriptors to fetch.
+		 */
+		wmb();
+
+		writel(xdp_ring->next_to_use, xdp_ring->tail);
+	}
+
 	rx_ring->skb = skb;
 
 	u64_stats_update_begin(&rx_ring->syncp);
@@ -3187,6 +3242,59 @@ static inline int i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
 	return -1;
 }
 
+/**
+ * i40e_xmit_xdp_ring - transmits an XDP buffer to an XDP Tx ring
+ * @xdp: data to transmit
+ * @xdp_ring: XDP Tx ring
+ **/
+static int i40e_xmit_xdp_ring(struct xdp_buff *xdp,
+			      struct i40e_ring *xdp_ring)
+{
+	u32 size = xdp->data_end - xdp->data;
+	u16 i = xdp_ring->next_to_use;
+	struct i40e_tx_buffer *tx_bi;
+	struct i40e_tx_desc *tx_desc;
+	dma_addr_t dma;
+
+	if (!unlikely(I40E_DESC_UNUSED(xdp_ring))) {
+		xdp_ring->tx_stats.tx_busy++;
+		return I40E_XDP_CONSUMED;
+	}
+
+	dma = dma_map_single(xdp_ring->dev, xdp->data, size, DMA_TO_DEVICE);
+	if (dma_mapping_error(xdp_ring->dev, dma))
+		return I40E_XDP_CONSUMED;
+
+	tx_bi = &xdp_ring->tx_bi[i];
+	tx_bi->bytecount = size;
+	tx_bi->gso_segs = 1;
+	tx_bi->raw_buf = xdp->data;
+
+	/* record length, and DMA address */
+	dma_unmap_len_set(tx_bi, len, size);
+	dma_unmap_addr_set(tx_bi, dma, dma);
+
+	tx_desc = I40E_TX_DESC(xdp_ring, i);
+	tx_desc->buffer_addr = cpu_to_le64(dma);
+	tx_desc->cmd_type_offset_bsz = build_ctob(I40E_TX_DESC_CMD_ICRC
+						  | I40E_TXD_CMD,
+						  0, size, 0);
+
+	/* Make certain all of the status bits have been updated
+	 * before next_to_watch is written.
+	 */
+	smp_wmb();
+
+	i++;
+	if (i == xdp_ring->count)
+		i = 0;
+
+	tx_bi->next_to_watch = tx_desc;
+	xdp_ring->next_to_use = i;
+
+	return I40E_XDP_TX;
+}
+
 /**
  * i40e_xmit_frame_ring - Sends buffer on Tx ring
  * @skb:     send buffer

drivers/net/ethernet/intel/i40e/i40e_txrx.h

@@ -396,6 +396,7 @@ struct i40e_ring {
 	u16 flags;
 #define I40E_TXR_FLAGS_WB_ON_ITR		BIT(0)
 #define I40E_RXR_FLAGS_BUILD_SKB_ENABLED	BIT(1)
+#define I40E_TXR_FLAGS_XDP			BIT(2)
 
 	/* stats structs */
 	struct i40e_queue_stats	stats;
@@ -438,6 +439,16 @@ static inline void clear_ring_build_skb_enabled(struct i40e_ring *ring)
 	ring->flags &= ~I40E_RXR_FLAGS_BUILD_SKB_ENABLED;
 }
 
+static inline bool ring_is_xdp(struct i40e_ring *ring)
+{
+	return !!(ring->flags & I40E_TXR_FLAGS_XDP);
+}
+
+static inline void set_ring_xdp(struct i40e_ring *ring)
+{
+	ring->flags |= I40E_TXR_FLAGS_XDP;
+}
+
 enum i40e_latency_range {
 	I40E_LOWEST_LATENCY = 0,
 	I40E_LOW_LATENCY = 1,