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, 29 insertions, 15 deletions

diff --git a/drivers/net/wireless/zd1211rw/zd_mac.c b/drivers/net/wireless/zd1211rw/zd_mac.c
index 55b7fbdc85dc..6d666359a42f 100644
--- a/drivers/net/wireless/zd1211rw/zd_mac.c
+++ b/drivers/net/wireless/zd1211rw/zd_mac.c
@@ -796,18 +796,40 @@ static void set_rx_filter_handler(struct work_struct *work)
                 dev_err(zd_mac_dev(mac), "set_rx_filter_handler error %d\n", r);
 }
 
+static u64 zd_op_prepare_multicast(struct ieee80211_hw *hw,
+                                   int mc_count, struct dev_addr_list *mclist)
+{
+        struct zd_mac *mac = zd_hw_mac(hw);
+        struct zd_mc_hash hash;
+        int i;
+
+        zd_mc_clear(&hash);
+
+        for (i = 0; i < mc_count; i++) {
+                if (!mclist)
+                        break;
+                dev_dbg_f(zd_mac_dev(mac), "mc addr %pM\n", mclist->dmi_addr);
+                zd_mc_add_addr(&hash, mclist->dmi_addr);
+                mclist = mclist->next;
+        }
+
+        return hash.low | ((u64)hash.high << 32);
+}
+
 #define SUPPORTED_FIF_FLAGS \
         (FIF_PROMISC_IN_BSS | FIF_ALLMULTI | FIF_FCSFAIL | FIF_CONTROL | \
         FIF_OTHER_BSS | FIF_BCN_PRBRESP_PROMISC)
 static void zd_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 zd_mc_hash hash;
+        struct zd_mc_hash hash = {
+                .low = multicast,
+                .high = multicast >> 32,
+        };
         struct zd_mac *mac = zd_hw_mac(hw);
         unsigned long flags;
-        int i;
 
         /* Only deal with supported flags */
         changed_flags &= SUPPORTED_FIF_FLAGS;
@@ -819,25 +841,16 @@ static void zd_op_configure_filter(struct ieee80211_hw *hw,
         if (!changed_flags)
                 return;
 
-        if (*new_flags & (FIF_PROMISC_IN_BSS | FIF_ALLMULTI)) {
+        if (*new_flags & (FIF_PROMISC_IN_BSS | FIF_ALLMULTI))
                 zd_mc_add_all(&hash);
-        } else {
-                zd_mc_clear(&hash);
-                for (i = 0; i < mc_count; i++) {
-                        if (!mclist)
-                                break;
-                        dev_dbg_f(zd_mac_dev(mac), "mc addr %pM\n",
-                                  mclist->dmi_addr);
-                        zd_mc_add_addr(&hash, mclist->dmi_addr);
-                        mclist = mclist->next;
-                }
-        }
 
         spin_lock_irqsave(&mac->lock, flags);
         mac->pass_failed_fcs = !!(*new_flags & FIF_FCSFAIL);
         mac->pass_ctrl = !!(*new_flags & FIF_CONTROL);
         mac->multicast_hash = hash;
         spin_unlock_irqrestore(&mac->lock, flags);
+
+        /* XXX: these can be called here now, can sleep now! */
         queue_work(zd_workqueue, &mac->set_multicast_hash_work);
 
         if (changed_flags & FIF_CONTROL)
@@ -940,6 +953,7 @@ static const struct ieee80211_ops zd_ops = {
         .add_interface          = zd_op_add_interface,
         .remove_interface       = zd_op_remove_interface,
         .config                 = zd_op_config,
+        .prepare_multicast      = zd_op_prepare_multicast,
         .configure_filter       = zd_op_configure_filter,
         .bss_info_changed       = zd_op_bss_info_changed,
         .get_tsf                = zd_op_get_tsf,