mac80211: support creating wiphy w/out creating wlanX

This will be helpful when using the mac80211_hwsim
wiphys and automated testing.  Let user create the
vifs as needed, and named as expected.
Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/mac80211.h

@@ -1583,6 +1583,10 @@ struct ieee80211_tx_control {
  *	a virtual monitor interface when monitor interfaces are the only
  *	active interfaces.
  *
+ * @IEEE80211_HW_NO_AUTO_VIF: The driver would like for no wlanX to
+ *	be created.  It is expected user-space will create vifs as
+ *	desired (and thus have them named as desired).
+ *
  * @IEEE80211_HW_QUEUE_CONTROL: The driver wants to control per-interface
  *	queue mapping in order to use different queues (not just one per AC)
  *	for different virtual interfaces. See the doc section on HW queue
@@ -1629,7 +1633,8 @@ enum ieee80211_hw_flags {
 	IEEE80211_HW_SUPPORTS_DYNAMIC_PS		= 1<<12,
 	IEEE80211_HW_MFP_CAPABLE			= 1<<13,
 	IEEE80211_HW_WANT_MONITOR_VIF			= 1<<14,
-	/* free slots */
+	IEEE80211_HW_NO_AUTO_VIF			= 1<<15,
+	/* free slot */
 	IEEE80211_HW_SUPPORTS_UAPSD			= 1<<17,
 	IEEE80211_HW_REPORTS_TX_ACK_STATUS		= 1<<18,
 	IEEE80211_HW_CONNECTION_MONITOR			= 1<<19,

net/mac80211/main.c

@@ -1023,7 +1023,8 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 	}
 
 	/* add one default STA interface if supported */
-	if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_STATION)) {
+	if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_STATION) &&
+	    !(hw->flags & IEEE80211_HW_NO_AUTO_VIF)) {
 		result = ieee80211_if_add(local, "wlan%d", NULL,
 					  NL80211_IFTYPE_STATION, NULL);
 		if (result)