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, 25 insertions, 18 deletions

diff --git a/drivers/net/wireless/ath/ar9170/main.c b/drivers/net/wireless/ath/ar9170/main.c
index ea8c9419336d..6a9462e4fd87 100644
--- a/drivers/net/wireless/ath/ar9170/main.c
+++ b/drivers/net/wireless/ath/ar9170/main.c
@@ -2100,10 +2100,29 @@ unlock:
         mutex_unlock(&ar->mutex);
 }
 
+static u64 ar9170_op_prepare_multicast(struct ieee80211_hw *hw, int mc_count,
+                                       struct dev_addr_list *mclist)
+{
+        u64 mchash;
+        int i;
+
+        /* always get broadcast frames */
+        mchash = 1ULL << (0xff >> 2);
+
+        for (i = 0; i < mc_count; i++) {
+                if (WARN_ON(!mclist))
+                        break;
+                mchash |= 1ULL << (mclist->dmi_addr[5] >> 2);
+                mclist = mclist->next;
+        }
+
+        return mchash;
+}
+
 static void ar9170_op_configure_filter(struct ieee80211_hw *hw,
                                        unsigned int changed_flags,
                                        unsigned int *new_flags,
-                                       int mc_count, struct dev_mc_list *mclist)
+                                       u64 multicast)
 {
         struct ar9170 *ar = hw->priv;
 
@@ -2116,24 +2135,11 @@ static void ar9170_op_configure_filter(struct ieee80211_hw *hw,
          * then checking the error flags, later.
          */
 
-        if (changed_flags & FIF_ALLMULTI) {
-                if (*new_flags & FIF_ALLMULTI) {
-                        ar->want_mc_hash = ~0ULL;
-                } else {
-                        u64 mchash;
-                        int i;
-
-                        /* always get broadcast frames */
-                        mchash = 1ULL << (0xff >> 2);
+        if (changed_flags & FIF_ALLMULTI && *new_flags & FIF_ALLMULTI)
+                        multicast = ~0ULL;
 
-                        for (i = 0; i < mc_count; i++) {
-                                if (WARN_ON(!mclist))
-                                        break;
-                                mchash |= 1ULL << (mclist->dmi_addr[5] >> 2);
-                                mclist = mclist->next;
-                        }
-                ar->want_mc_hash = mchash;
-                }
+        if (multicast != ar->want_mc_hash) {
+                ar->want_mc_hash = multicast;
                 set_bit(AR9170_FILTER_CHANGED_MULTICAST, &ar->filter_changed);
         }
 
@@ -2543,6 +2549,7 @@ static const struct ieee80211_ops ar9170_ops = {
         .add_interface          = ar9170_op_add_interface,
         .remove_interface       = ar9170_op_remove_interface,
         .config                 = ar9170_op_config,
+        .prepare_multicast      = ar9170_op_prepare_multicast,
         .configure_filter       = ar9170_op_configure_filter,
         .conf_tx                = ar9170_conf_tx,
         .bss_info_changed       = ar9170_op_bss_info_changed,