mac80211: allow configure_filter callback to sleep

Over time, a whole bunch of drivers have come up
with their own scheme to delay the configure_filter
operation to a workqueue. To be able to simplify
things, allow configure_filter to sleep, and add
a new prepare_multicast callback that drivers that
need the multicast address list implement. This new
callback must be atomic, but most drivers either
don't care or just calculate a hash which can be
done atomically and then uploaded to the hardware
non-atomically.

A cursory look suggests that at76c50x-usb, ar9170,
mwl8k (which is actually very broken now), rt2x00,
wl1251, wl1271 and zd1211 should make use of this
new capability.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 15 insertions, 6 deletions

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 76d43e12cc29..bc865206e5f1 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1219,10 +1219,13 @@ ieee80211_get_alt_retry_rate(const struct ieee80211_hw *hw,
  * the driver's configure_filter() function which frames should be
  * passed to mac80211 and which should be filtered out.
  *
- * The configure_filter() callback is invoked with the parameters
- * @mc_count and @mc_list for the combined multicast address list
- * of all virtual interfaces, @changed_flags telling which flags
- * were changed and @total_flags with the new flag states.
+ * Before configure_filter() is invoked, the prepare_multicast()
+ * callback is invoked with the parameters @mc_count and @mc_list
+ * for the combined multicast address list of all virtual interfaces.
+ * It's use is optional, and it returns a u64 that is passed to
+ * configure_filter(). Additionally, configure_filter() has the
+ * arguments @changed_flags telling which flags were changed and
+ * @total_flags with the new flag states.
  *
  * If your device has no multicast address filters your driver will
  * need to check both the %FIF_ALLMULTI flag and the @mc_count
@@ -1375,9 +1378,13 @@ enum ieee80211_ampdu_mlme_action {
  *	for association indication. The @changed parameter indicates which
  *	of the bss parameters has changed when a call is made.
  *
+ * @prepare_multicast: Prepare for multicast filter configuration.
+ *	This callback is optional, and its return value is passed
+ *	to configure_filter(). This callback must be atomic.
+ *
  * @configure_filter: Configure the device's RX filter.
  *	See the section "Frame filtering" for more information.
- *	This callback must be implemented and atomic.
+ *	This callback must be implemented.
  *
  * @set_tim: Set TIM bit. mac80211 calls this function when a TIM bit
  * 	must be set or cleared for a given STA. Must be atomic.
@@ -1479,10 +1486,12 @@ struct ieee80211_ops {
 				 struct ieee80211_vif *vif,
 				 struct ieee80211_bss_conf *info,
 				 u32 changed);
+	u64 (*prepare_multicast)(struct ieee80211_hw *hw,
+				 int mc_count, struct dev_addr_list *mc_list);
 	void (*configure_filter)(struct ieee80211_hw *hw,
 				 unsigned int changed_flags,
 				 unsigned int *total_flags,
-				 int mc_count, struct dev_addr_list *mc_list);
+				 u64 multicast);
 	int (*set_tim)(struct ieee80211_hw *hw, struct ieee80211_sta *sta,
 		       bool set);
 	int (*set_key)(struct ieee80211_hw *hw, enum set_key_cmd cmd,