[PATCH RFC net-next 25/34] idpf: add support for .ndo_xdp_xmit()

[Alexander Lobakin <aleksander.lobakin@intel.com>]

Use libie XDP infra to implement .ndo_xdp_xmit() in idpf.
The Tx callbacks are reused from XDP_TX code. XDP redirect target
feature is set/cleared depending on the XDP prog presence, as for now
we still don't allocate XDP Tx queues when there's no program.

Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
---
 drivers/net/ethernet/intel/idpf/idpf_lib.c |  1 +
 drivers/net/ethernet/intel/idpf/idpf_xdp.c | 34 ++++++++++++++++++++++
 drivers/net/ethernet/intel/idpf/idpf_xdp.h |  2 ++
 3 files changed, 37 insertions(+)

diff --git a/drivers/net/ethernet/intel/idpf/idpf_lib.c b/drivers/net/ethernet/intel/idpf/idpf_lib.c
index a19704c4c421..7c3d45f84e1b 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_lib.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_lib.c
@@ -2451,6 +2451,7 @@ static const struct net_device_ops idpf_netdev_ops_splitq = {
 	.ndo_set_features = idpf_set_features,
 	.ndo_tx_timeout = idpf_tx_timeout,
 	.ndo_bpf = idpf_xdp,
+	.ndo_xdp_xmit = idpf_xdp_xmit,
 };
 
 static const struct net_device_ops idpf_netdev_ops_singleq = {
diff --git a/drivers/net/ethernet/intel/idpf/idpf_xdp.c b/drivers/net/ethernet/intel/idpf/idpf_xdp.c
index b9952ebda4fb..b4f096186302 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_xdp.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_xdp.c
@@ -313,6 +313,35 @@ bool __idpf_xdp_run_prog(struct xdp_buff *xdp, struct libie_xdp_tx_bulk *bq)
 	return libie_xdp_run_prog(xdp, bq, idpf_xdp_tx_flush_bulk);
 }
 
+/**
+ * idpf_xdp_xmit - submit packets to xdp ring for transmission
+ * @dev: netdev
+ * @n: number of xdp frames to be transmitted
+ * @frames: xdp frames to be transmitted
+ * @flags: transmit flags
+ *
+ * Returns number of frames successfully sent. Frames that fail are
+ * free'ed via XDP return API.
+ * For error cases, a negative errno code is returned and no-frames
+ * are transmitted (caller must handle freeing frames).
+ */
+int idpf_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames,
+		  u32 flags)
+{
+	struct idpf_netdev_priv *np = netdev_priv(dev);
+	struct idpf_vport *vport = np->vport;
+
+	if (unlikely(!netif_carrier_ok(dev) || !vport->link_up))
+		return -ENETDOWN;
+	if (unlikely(!idpf_xdp_is_prog_ena(vport)))
+		return -ENXIO;
+
+	return libie_xdp_xmit_do_bulk(dev, n, frames, flags,
+				      &vport->txqs[vport->xdp_txq_offset],
+				      vport->num_xdp_txq, idpf_xdp_tx_prep,
+				      idpf_xdp_tx_xmit, idpf_xdp_tx_finalize);
+}
+
 /**
  * idpf_xdp_reconfig_queues - reconfigure queues after the XDP setup
  * @vport: vport to load or unload XDP for
@@ -410,6 +439,11 @@ idpf_xdp_setup_prog(struct idpf_vport *vport, struct bpf_prog *prog,
 		return err;
 	}
 
+	if (prog)
+		xdp_features_set_redirect_target(vport->netdev, false);
+	else
+		xdp_features_clear_redirect_target(vport->netdev);
+
 	if (vport_is_up) {
 		err = idpf_vport_open(vport, false);
 		if (err) {
diff --git a/drivers/net/ethernet/intel/idpf/idpf_xdp.h b/drivers/net/ethernet/intel/idpf/idpf_xdp.h
index 1f299c268ca5..f1444482f69d 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_xdp.h
+++ b/drivers/net/ethernet/intel/idpf/idpf_xdp.h
@@ -31,6 +31,8 @@ static inline void idpf_xdp_finalize_rx(struct libie_xdp_tx_bulk *bq)
 		__idpf_xdp_finalize_rx(bq);
 }
 
+int idpf_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames,
+		  u32 flags);
 int idpf_xdp(struct net_device *netdev, struct netdev_bpf *xdp);
 
 #endif /* _IDPF_XDP_H_ */
-- 
2.43.0