ice: do switchdev slow-path Rx using PF VSI

Add an ICE_RX_FLAG_MULTIDEV flag to Rx ring.

If it is set try to find correct port representor. Do it based on
src_vsi value stored in flex descriptor. Ids of representor pointers
stored in xarray are equal to corresponding src_vsi value. Thanks to
that we can directly get correct representor if we have src_vsi value.

Set multidev flag during ring configuration.

If the mode is switchdev, change the ring descriptor to the one that
contains src_vsi value.

PF netdev should be reconfigured, do it by calling ice_down() and
ice_up() if the netdev was up before configuring switchdev.

Reviewed-by: Marcin Szycik <marcin.szycik@linux.intel.com>
Signed-off-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Tested-by: Sujai Buvaneswaran <sujai.buvaneswaran@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

Author: Michal Swiatkowski

drivers/net/ethernet/intel/ice/ice_base.c

@@ -452,6 +452,14 @@ static int ice_setup_rx_ctx(struct ice_rx_ring *ring)
 	/* Rx queue threshold in units of 64 */
 	rlan_ctx.lrxqthresh = 1;
 
+	/* PF acts as uplink for switchdev; set flex descriptor with src_vsi
+	 * metadata and flags to allow redirecting to PR netdev
+	 */
+	if (ice_is_eswitch_mode_switchdev(vsi->back)) {
+		ring->flags |= ICE_RX_FLAGS_MULTIDEV;
+		rxdid = ICE_RXDID_FLEX_NIC_2;
+	}
+
 	/* Enable Flexible Descriptors in the queue context which
 	 * allows this driver to select a specific receive descriptor format
 	 * increasing context priority to pick up profile ID; default is 0x01;

drivers/net/ethernet/intel/ice/ice_eswitch.c

@@ -21,8 +21,13 @@ static int ice_eswitch_setup_env(struct ice_pf *pf)
 {
 	struct ice_vsi *uplink_vsi = pf->eswitch.uplink_vsi;
 	struct net_device *netdev = uplink_vsi->netdev;
+	bool if_running = netif_running(netdev);
 	struct ice_vsi_vlan_ops *vlan_ops;
 
+	if (if_running && !test_and_set_bit(ICE_VSI_DOWN, uplink_vsi->state))
+		if (ice_down(uplink_vsi))
+			return -ENODEV;
+
 	ice_remove_vsi_fltr(&pf->hw, uplink_vsi->idx);
 
 	netif_addr_lock_bh(netdev);
@@ -51,8 +56,13 @@ static int ice_eswitch_setup_env(struct ice_pf *pf)
 	if (ice_vsi_update_local_lb(uplink_vsi, true))
 		goto err_override_local_lb;
 
+	if (if_running && ice_up(uplink_vsi))
+		goto err_up;
+
 	return 0;
 
+err_up:
+	ice_vsi_update_local_lb(uplink_vsi, false);
 err_override_local_lb:
 	ice_vsi_update_security(uplink_vsi, ice_vsi_ctx_clear_allow_override);
 err_override_uplink:
@@ -69,6 +79,9 @@ static int ice_eswitch_setup_env(struct ice_pf *pf)
 	ice_fltr_add_mac_and_broadcast(uplink_vsi,
 				       uplink_vsi->port_info->mac.perm_addr,
 				       ICE_FWD_TO_VSI);
+	if (if_running)
+		ice_up(uplink_vsi);
+
 	return -ENODEV;
 }
 
@@ -493,3 +506,26 @@ void ice_eswitch_rebuild(struct ice_pf *pf)
 	xa_for_each(&pf->eswitch.reprs, id, repr)
 		ice_eswitch_detach(pf, repr->vf);
 }
+
+/**
+ * ice_eswitch_get_target - get netdev based on src_vsi from descriptor
+ * @rx_ring: ring used to receive the packet
+ * @rx_desc: descriptor used to get src_vsi value
+ *
+ * Get src_vsi value from descriptor and load correct representor. If it isn't
+ * found return rx_ring->netdev.
+ */
+struct net_device *ice_eswitch_get_target(struct ice_rx_ring *rx_ring,
+					  union ice_32b_rx_flex_desc *rx_desc)
+{
+	struct ice_eswitch *eswitch = &rx_ring->vsi->back->eswitch;
+	struct ice_32b_rx_flex_desc_nic_2 *desc;
+	struct ice_repr *repr;
+
+	desc = (struct ice_32b_rx_flex_desc_nic_2 *)rx_desc;
+	repr = xa_load(&eswitch->reprs, le16_to_cpu(desc->src_vsi));
+	if (!repr)
+		return rx_ring->netdev;
+
+	return repr->netdev;
+}

drivers/net/ethernet/intel/ice/ice_eswitch.h

@@ -26,6 +26,8 @@ void ice_eswitch_set_target_vsi(struct sk_buff *skb,
 				struct ice_tx_offload_params *off);
 netdev_tx_t
 ice_eswitch_port_start_xmit(struct sk_buff *skb, struct net_device *netdev);
+struct net_device *ice_eswitch_get_target(struct ice_rx_ring *rx_ring,
+					  union ice_32b_rx_flex_desc *rx_desc);
 #else /* CONFIG_ICE_SWITCHDEV */
 static inline void ice_eswitch_detach(struct ice_pf *pf, struct ice_vf *vf) { }
 
@@ -76,5 +78,12 @@ ice_eswitch_port_start_xmit(struct sk_buff *skb, struct net_device *netdev)
 {
 	return NETDEV_TX_BUSY;
 }
+
+static inline struct net_device *
+ice_eswitch_get_target(struct ice_rx_ring *rx_ring,
+		       union ice_32b_rx_flex_desc *rx_desc)
+{
+	return rx_ring->netdev;
+}
 #endif /* CONFIG_ICE_SWITCHDEV */
 #endif /* _ICE_ESWITCH_H_ */

drivers/net/ethernet/intel/ice/ice_txrx.h

@@ -365,6 +365,7 @@ struct ice_rx_ring {
 	u8 ptp_rx;
 #define ICE_RX_FLAGS_RING_BUILD_SKB	BIT(1)
 #define ICE_RX_FLAGS_CRC_STRIP_DIS	BIT(2)
+#define ICE_RX_FLAGS_MULTIDEV		BIT(3)
 	u8 flags;
 	/* CL5 - 5th cacheline starts here */
 	struct xdp_rxq_info xdp_rxq;

drivers/net/ethernet/intel/ice/ice_txrx_lib.c

@@ -236,7 +236,14 @@ ice_process_skb_fields(struct ice_rx_ring *rx_ring,
 	ice_rx_hash_to_skb(rx_ring, rx_desc, skb, ptype);
 
 	/* modifies the skb - consumes the enet header */
-	skb->protocol = eth_type_trans(skb, rx_ring->netdev);
+	if (unlikely(rx_ring->flags & ICE_RX_FLAGS_MULTIDEV)) {
+		struct net_device *netdev = ice_eswitch_get_target(rx_ring,
+								   rx_desc);
+
+		skb->protocol = eth_type_trans(skb, netdev);
+	} else {
+		skb->protocol = eth_type_trans(skb, rx_ring->netdev);
+	}
 
 	ice_rx_csum(rx_ring, skb, rx_desc, ptype);