mac80211: Support dynamic AP mode channel width changes

Implement the new cfg80211 capability to enable mac80211-based drivers
to support for dynamic channel bandwidth changes (e.g., HT 20/40 MHz
changes).

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/cfg.c

@@ -3958,6 +3958,21 @@ static int ieee80211_set_qos_map(struct wiphy *wiphy,
 	return 0;
 }
 
+static int ieee80211_set_ap_chanwidth(struct wiphy *wiphy,
+				      struct net_device *dev,
+				      struct cfg80211_chan_def *chandef)
+{
+	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+	int ret;
+	u32 changed = 0;
+
+	ret = ieee80211_vif_change_bandwidth(sdata, chandef, &changed);
+	if (ret == 0)
+		ieee80211_bss_info_change_notify(sdata, changed);
+
+	return ret;
+}
+
 const struct cfg80211_ops mac80211_config_ops = {
 	.add_virtual_intf = ieee80211_add_iface,
 	.del_virtual_intf = ieee80211_del_iface,
@@ -4038,4 +4053,5 @@ const struct cfg80211_ops mac80211_config_ops = {
 	.start_radar_detection = ieee80211_start_radar_detection,
 	.channel_switch = ieee80211_channel_switch,
 	.set_qos_map = ieee80211_set_qos_map,
+	.set_ap_chanwidth = ieee80211_set_ap_chanwidth,
 };