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 55b7fbdc85d..6d666359a42 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,