mac80211: implement multi-vif in-place reservations

Multi-vif in-place reservations happen when
it is impossible to allocate more channel contexts
as indicated by interface combinations.

Such reservations are not finalized until all
assigned interfaces are ready.

This still doesn't handle all possible cases
(i.e. degradation of number of channels) properly.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/mac80211.h

@@ -1606,12 +1606,6 @@ struct ieee80211_tx_control {
  *	is not enabled the default action is to disconnect when getting the
  *	CSA frame.
  *
- * @IEEE80211_HW_CHANGE_RUNNING_CHANCTX: The hardware can change a
- *	channel context on-the-fly.  This is needed for channel switch
- *	on single-channel hardware.  It can also be used as an
- *	optimization in certain channel switch cases with
- *	multi-channel.
- *
  * @IEEE80211_SINGLE_HW_SCAN_ON_ALL_BANDS: The HW supports scanning on all bands
  *	in one command, mac80211 doesn't have to run separate scans per band.
  */
@@ -1645,7 +1639,7 @@ enum ieee80211_hw_flags {
 	IEEE80211_HW_TIMING_BEACON_ONLY			= 1<<26,
 	IEEE80211_HW_SUPPORTS_HT_CCK_RATES		= 1<<27,
 	IEEE80211_HW_CHANCTX_STA_CSA			= 1<<28,
-	IEEE80211_HW_CHANGE_RUNNING_CHANCTX		= 1<<29,
+	/* bit 29 unused */
 	IEEE80211_SINGLE_HW_SCAN_ON_ALL_BANDS		= 1<<30,
 };