wifi: mac80211: add support for letting drivers register tc offload support

On newer MediaTek SoCs (e.g. MT7986), WLAN->WLAN or WLAN->Ethernet flows can
be offloaded by the SoC. In order to support that, the .ndo_setup_tc op is
needed.
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20230321091248.30947-1-nbd@nbd.nameSigned-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/mac80211.h

@@ -4227,6 +4227,10 @@ struct ieee80211_prep_tx_info {
  * @set_hw_timestamp: Enable/disable HW timestamping of TM/FTM frames. This is
  *	not restored at HW reset by mac80211 so drivers need to take care of
  *	that.
+ * @net_setup_tc: Called from .ndo_setup_tc in order to prepare hardware
+ *	flow offloading for flows originating from the vif.
+ *	Note that the driver must not assume that the vif driver_data is valid
+ *	at this point, since the callback can be called during netdev teardown.
  */
 struct ieee80211_ops {
 	void (*tx)(struct ieee80211_hw *hw,
@@ -4593,6 +4597,11 @@ struct ieee80211_ops {
 	int (*set_hw_timestamp)(struct ieee80211_hw *hw,
 				struct ieee80211_vif *vif,
 				struct cfg80211_set_hw_timestamp *hwts);
+	int (*net_setup_tc)(struct ieee80211_hw *hw,
+			    struct ieee80211_vif *vif,
+			    struct net_device *dev,
+			    enum tc_setup_type type,
+			    void *type_data);
 };
 
 /**

net/mac80211/driver-ops.h

@@ -1502,6 +1502,23 @@ static inline int drv_net_fill_forward_path(struct ieee80211_local *local,
 	return ret;
 }
 
+static inline int drv_net_setup_tc(struct ieee80211_local *local,
+				   struct ieee80211_sub_if_data *sdata,
+				   struct net_device *dev,
+				   enum tc_setup_type type, void *type_data)
+{
+	int ret = -EOPNOTSUPP;
+
+	sdata = get_bss_sdata(sdata);
+	trace_drv_net_setup_tc(local, sdata, type);
+	if (local->ops->net_setup_tc)
+		ret = local->ops->net_setup_tc(&local->hw, &sdata->vif, dev,
+					       type, type_data);
+	trace_drv_return_int(local, ret);
+
+	return ret;
+}
+
 int drv_change_vif_links(struct ieee80211_local *local,
 			 struct ieee80211_sub_if_data *sdata,
 			 u16 old_links, u16 new_links,

net/mac80211/ieee80211_i.h

@@ -1939,7 +1939,8 @@ void ieee80211_color_collision_detection_work(struct work_struct *work);
 /* interface handling */
 #define MAC80211_SUPPORTED_FEATURES_TX	(NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM | \
 					 NETIF_F_HW_CSUM | NETIF_F_SG | \
-					 NETIF_F_HIGHDMA | NETIF_F_GSO_SOFTWARE)
+					 NETIF_F_HIGHDMA | NETIF_F_GSO_SOFTWARE | \
+					 NETIF_F_HW_TC)
 #define MAC80211_SUPPORTED_FEATURES_RX	(NETIF_F_RXCSUM)
 #define MAC80211_SUPPORTED_FEATURES	(MAC80211_SUPPORTED_FEATURES_TX | \
 					 MAC80211_SUPPORTED_FEATURES_RX)

net/mac80211/iface.c

@@ -813,6 +813,15 @@ ieee80211_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
 	dev_fetch_sw_netstats(stats, dev->tstats);
 }
 
+static int ieee80211_netdev_setup_tc(struct net_device *dev,
+				     enum tc_setup_type type, void *type_data)
+{
+	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+	struct ieee80211_local *local = sdata->local;
+
+	return drv_net_setup_tc(local, sdata, dev, type, type_data);
+}
+
 static const struct net_device_ops ieee80211_dataif_ops = {
 	.ndo_open		= ieee80211_open,
 	.ndo_stop		= ieee80211_stop,
@@ -821,6 +830,7 @@ static const struct net_device_ops ieee80211_dataif_ops = {
 	.ndo_set_rx_mode	= ieee80211_set_multicast_list,
 	.ndo_set_mac_address 	= ieee80211_change_mac,
 	.ndo_get_stats64	= ieee80211_get_stats64,
+	.ndo_setup_tc		= ieee80211_netdev_setup_tc,
 };
 
 static u16 ieee80211_monitor_select_queue(struct net_device *dev,
@@ -929,6 +939,7 @@ static const struct net_device_ops ieee80211_dataif_8023_ops = {
 	.ndo_set_mac_address	= ieee80211_change_mac,
 	.ndo_get_stats64	= ieee80211_get_stats64,
 	.ndo_fill_forward_path	= ieee80211_netdev_fill_forward_path,
+	.ndo_setup_tc		= ieee80211_netdev_setup_tc,
 };
 
 static bool ieee80211_iftype_supports_hdr_offload(enum nl80211_iftype iftype)

net/mac80211/trace.h

@@ -2478,6 +2478,31 @@ DEFINE_EVENT(sta_event, drv_net_fill_forward_path,
 	TP_ARGS(local, sdata, sta)
 );
 
+TRACE_EVENT(drv_net_setup_tc,
+	TP_PROTO(struct ieee80211_local *local,
+		 struct ieee80211_sub_if_data *sdata,
+		 u8 type),
+
+	TP_ARGS(local, sdata, type),
+
+	TP_STRUCT__entry(
+		LOCAL_ENTRY
+		VIF_ENTRY
+		__field(u8, type)
+	),
+
+	TP_fast_assign(
+		LOCAL_ASSIGN;
+		VIF_ASSIGN;
+		__entry->type = type;
+	),
+
+	TP_printk(
+		LOCAL_PR_FMT VIF_PR_FMT " type:%d\n",
+		LOCAL_PR_ARG, VIF_PR_ARG, __entry->type
+	)
+);
+
 TRACE_EVENT(drv_change_vif_links,
 	TP_PROTO(struct ieee80211_local *local,
 		 struct ieee80211_sub_if_data *sdata,