qtnfmac: track broadcast domain of each interface

If firmware reports that it supports hardware switch capabilities,
driver needs to track and notify device whenever broadcast domain
of a particular network device changes (ie. whenever it's upper
master device changes).

Firmware needs a unique ID to tell broadcast domains from each other
which is an opaque number otherwise. For that purpose we can use
netspace:ifidx pair to uniquely identify each broadcast domain:
 - if netdev is not part of a bridge, then use it's own ifidx
   as a broadcast domain ID
 - if netdev is part of a bridge, then use bridge netdev ifidx
   as broadcast domain ID

Firmware makes sure that packets are only forwarded between
interfaces marked with the same broadcast domain ID.
Signed-off-by: Igor Mitsyanko <igor.mitsyanko.os@quantenna.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/quantenna/qtnfmac/bus.h

@@ -54,6 +54,7 @@ struct qtnf_bus {
 	struct work_struct event_work;
 	struct mutex bus_lock; /* lock during command/event processing */
 	struct dentry *dbg_dir;
+	struct notifier_block netdev_nb;
 	/* bus private data */
 	char bus_priv[0] __aligned(sizeof(void *));
 };

drivers/net/wireless/quantenna/qtnfmac/cfg80211.c

@@ -248,6 +248,15 @@ static struct wireless_dev *qtnf_add_virtual_intf(struct wiphy *wiphy,
 		goto error_del_vif;
 	}
 
+	if (mac->bus->hw_info.hw_capab & QLINK_HW_CAPAB_HW_BRIDGE) {
+		ret = qtnf_cmd_netdev_changeupper(vif, vif->netdev->ifindex);
+		if (ret) {
+			unregister_netdevice(vif->netdev);
+			vif->netdev = NULL;
+			goto error_del_vif;
+		}
+	}
+
 	vif->wdev.netdev = vif->netdev;
 	return &vif->wdev;
 

drivers/net/wireless/quantenna/qtnfmac/commands.c

@@ -2756,3 +2756,35 @@ int qtnf_cmd_send_wowlan_set(const struct qtnf_vif *vif,
 	qtnf_bus_unlock(bus);
 	return ret;
 }
+
+int qtnf_cmd_netdev_changeupper(const struct qtnf_vif *vif, int br_domain)
+{
+	struct qtnf_bus *bus = vif->mac->bus;
+	struct sk_buff *cmd_skb;
+	struct qlink_cmd_ndev_changeupper *cmd;
+	int ret;
+
+	cmd_skb = qtnf_cmd_alloc_new_cmdskb(vif->mac->macid, vif->vifid,
+					    QLINK_CMD_NDEV_EVENT,
+					    sizeof(*cmd));
+	if (!cmd_skb)
+		return -ENOMEM;
+
+	pr_debug("[VIF%u.%u] set broadcast domain to %d\n",
+		 vif->mac->macid, vif->vifid, br_domain);
+
+	cmd = (struct qlink_cmd_ndev_changeupper *)cmd_skb->data;
+	cmd->nehdr.event = cpu_to_le16(QLINK_NDEV_EVENT_CHANGEUPPER);
+	cmd->upper_type = QLINK_NDEV_UPPER_TYPE_BRIDGE;
+	cmd->br_domain = cpu_to_le32(br_domain);
+
+	qtnf_bus_lock(bus);
+	ret = qtnf_cmd_send(bus, cmd_skb);
+	qtnf_bus_unlock(bus);
+
+	if (ret)
+		pr_err("[VIF%u.%u] failed to set broadcast domain\n",
+		       vif->mac->macid, vif->vifid);
+
+	return ret;
+}

drivers/net/wireless/quantenna/qtnfmac/commands.h

@@ -75,5 +75,6 @@ int qtnf_cmd_set_tx_power(const struct qtnf_vif *vif,
 			  enum nl80211_tx_power_setting type, int mbm);
 int qtnf_cmd_send_wowlan_set(const struct qtnf_vif *vif,
 			     const struct cfg80211_wowlan *wowl);
+int qtnf_cmd_netdev_changeupper(const struct qtnf_vif *vif, int br_domain);
 
 #endif /* QLINK_COMMANDS_H_ */

drivers/net/wireless/quantenna/qtnfmac/core.c

@@ -613,6 +613,12 @@ static int qtnf_core_mac_attach(struct qtnf_bus *bus, unsigned int macid)
 		goto error_del_vif;
 	}
 
+	if (bus->hw_info.hw_capab & QLINK_HW_CAPAB_HW_BRIDGE) {
+		ret = qtnf_cmd_netdev_changeupper(vif, vif->netdev->ifindex);
+		if (ret)
+			goto error;
+	}
+
 	pr_debug("MAC%u initialized\n", macid);
 
 	return 0;
@@ -625,6 +631,54 @@ static int qtnf_core_mac_attach(struct qtnf_bus *bus, unsigned int macid)
 	return ret;
 }
 
+bool qtnf_netdev_is_qtn(const struct net_device *ndev)
+{
+	return ndev->netdev_ops == &qtnf_netdev_ops;
+}
+
+static int qtnf_core_netdevice_event(struct notifier_block *nb,
+				     unsigned long event, void *ptr)
+{
+	struct net_device *ndev = netdev_notifier_info_to_dev(ptr);
+	const struct netdev_notifier_changeupper_info *info;
+	struct qtnf_vif *vif;
+	int br_domain;
+	int ret = 0;
+
+	if (!qtnf_netdev_is_qtn(ndev))
+		return NOTIFY_DONE;
+
+	if (!net_eq(dev_net(ndev), &init_net))
+		return NOTIFY_OK;
+
+	vif = qtnf_netdev_get_priv(ndev);
+
+	switch (event) {
+	case NETDEV_CHANGEUPPER:
+		info = ptr;
+
+		if (!netif_is_bridge_master(info->upper_dev))
+			break;
+
+		pr_debug("[VIF%u.%u] change bridge: %s %s\n",
+			 vif->mac->macid, vif->vifid,
+			 netdev_name(info->upper_dev),
+			 info->linking ? "add" : "del");
+
+		if (info->linking)
+			br_domain = info->upper_dev->ifindex;
+		else
+			br_domain = ndev->ifindex;
+
+		ret = qtnf_cmd_netdev_changeupper(vif, br_domain);
+		break;
+	default:
+		break;
+	}
+
+	return notifier_from_errno(ret);
+}
+
 int qtnf_core_attach(struct qtnf_bus *bus)
 {
 	unsigned int i;
@@ -685,6 +739,15 @@ int qtnf_core_attach(struct qtnf_bus *bus)
 		}
 	}
 
+	if (bus->hw_info.hw_capab & QLINK_HW_CAPAB_HW_BRIDGE) {
+		bus->netdev_nb.notifier_call = qtnf_core_netdevice_event;
+		ret = register_netdevice_notifier(&bus->netdev_nb);
+		if (ret) {
+			pr_err("failed to register netdev notifier: %d\n", ret);
+			goto error;
+		}
+	}
+
 	bus->fw_state = QTNF_FW_STATE_RUNNING;
 	return 0;
 
@@ -698,6 +761,7 @@ void qtnf_core_detach(struct qtnf_bus *bus)
 {
 	unsigned int macid;
 
+	unregister_netdevice_notifier(&bus->netdev_nb);
 	qtnf_bus_data_rx_stop(bus);
 
 	for (macid = 0; macid < QTNF_MAX_MAC; macid++)

drivers/net/wireless/quantenna/qtnfmac/core.h

@@ -153,6 +153,7 @@ void qtnf_virtual_intf_cleanup(struct net_device *ndev);
 void qtnf_netdev_updown(struct net_device *ndev, bool up);
 void qtnf_scan_done(struct qtnf_wmac *mac, bool aborted);
 struct dentry *qtnf_get_debugfs_dir(void);
+bool qtnf_netdev_is_qtn(const struct net_device *ndev);
 
 static inline struct qtnf_vif *qtnf_netdev_get_priv(struct net_device *dev)
 {

drivers/net/wireless/quantenna/qtnfmac/qlink.h

@@ -59,6 +59,7 @@ struct qlink_msg_header {
  * @QLINK_HW_CAPAB_SCAN_RANDOM_MAC_ADDR: device supports MAC Address
  *	Randomization in probe requests.
  * @QLINK_HW_CAPAB_OBSS_SCAN: device can perform OBSS scanning.
+ * @QLINK_HW_CAPAB_HW_BRIDGE: device has hardware switch capabilities.
  */
 enum qlink_hw_capab {
 	QLINK_HW_CAPAB_REG_UPDATE		= BIT(0),
@@ -69,6 +70,7 @@ enum qlink_hw_capab {
 	QLINK_HW_CAPAB_OBSS_SCAN		= BIT(5),
 	QLINK_HW_CAPAB_SCAN_DWELL		= BIT(6),
 	QLINK_HW_CAPAB_SAE			= BIT(8),
+	QLINK_HW_CAPAB_HW_BRIDGE		= BIT(9),
 };
 
 enum qlink_iface_type {
@@ -219,6 +221,8 @@ struct qlink_sta_info_state {
  * @QLINK_CMD_START_CAC: start radar detection procedure on a specified channel.
  * @QLINK_CMD_TXPWR: get or set current channel transmit power for
  *	the specified MAC.
+ * @QLINK_CMD_NDEV_EVENT: signalizes changes made with a corresponding network
+ *	device.
  */
 enum qlink_cmd_type {
 	QLINK_CMD_FW_INIT		= 0x0001,
@@ -251,6 +255,7 @@ enum qlink_cmd_type {
 	QLINK_CMD_DEL_STA		= 0x0052,
 	QLINK_CMD_SCAN			= 0x0053,
 	QLINK_CMD_CHAN_STATS		= 0x0054,
+	QLINK_CMD_NDEV_EVENT		= 0x0055,
 	QLINK_CMD_CONNECT		= 0x0060,
 	QLINK_CMD_DISCONNECT		= 0x0061,
 	QLINK_CMD_PM_SET		= 0x0062,
@@ -771,6 +776,42 @@ struct qlink_cmd_wowlan_set {
 	u8 data[0];
 } __packed;
 
+enum qlink_ndev_event_type {
+	QLINK_NDEV_EVENT_CHANGEUPPER,
+};
+
+/**
+ * struct qlink_cmd_ndev_event - data for QLINK_CMD_NDEV_EVENT command
+ *
+ * @event: type of event, one of &enum qlink_ndev_event_type
+ */
+struct qlink_cmd_ndev_event {
+	struct qlink_cmd chdr;
+	__le16 event;
+	u8 rsvd[2];
+} __packed;
+
+enum qlink_ndev_upper_type {
+	QLINK_NDEV_UPPER_TYPE_NONE,
+	QLINK_NDEV_UPPER_TYPE_BRIDGE,
+};
+
+/**
+ * struct qlink_cmd_ndev_changeupper - data for QLINK_NDEV_EVENT_CHANGEUPPER
+ *
+ * @br_domain: layer 2 broadcast domain ID that ndev is a member of
+ * @upper_type: type of upper device, one of &enum qlink_ndev_upper_type
+ */
+struct qlink_cmd_ndev_changeupper {
+	struct qlink_cmd_ndev_event nehdr;
+	__le64 flags;
+	__le32 br_domain;
+	__le32 netspace_id;
+	__le16 vlanid;
+	u8 upper_type;
+	u8 rsvd[1];
+} __packed;
+
 /* QLINK Command Responses messages related definitions
  */