mt76: mt76x02: split beaconing

Sending beacons to the hardware always happens in batches. In order to
speed up beacon processing on usb devices, this patch splits out common
code an calls it only once.

Beacons are sequentially written into the beacon memory area, by
tracking its usage with the dev->beacon_data_count. For MBSS support
and buffered traffic dev->beacon_data_count is used to create the bypass
mask.

The code is also adapted for the mmio part of the driver, but should not
have any performance implication there.

MBSS tests were performed with AVM AC860 USB NIC with temporary support
for 5 BSS'. Different combinations of active vifs were created and
brought up. Afterwards connection and data transfer was tested for the
announced BSS'.
Signed-off-by: Markus Theil <markus.theil@tu-ilmenau.de>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt76x02.h

@@ -98,8 +98,7 @@ struct mt76x02_dev {
 
 	const struct mt76x02_beacon_ops *beacon_ops;
 
-	struct sk_buff *beacons[8];
-	u8 beacon_data_mask;
+	u8 beacon_data_count;
 
 	u8 tbtt_count;
 

drivers/net/wireless/mediatek/mt76/mt76x02_beacon.c

@@ -40,63 +40,22 @@ mt76x02_write_beacon(struct mt76x02_dev *dev, int offset, struct sk_buff *skb)
 	return 0;
 }
 
-static int
-__mt76x02_mac_set_beacon(struct mt76x02_dev *dev, u8 bcn_idx,
+int mt76x02_mac_set_beacon(struct mt76x02_dev *dev,
 			   struct sk_buff *skb)
 {
-	int beacon_len = dev->beacon_ops->slot_size;
-	int beacon_addr = MT_BEACON_BASE + (beacon_len * bcn_idx);
+	int bcn_len = dev->beacon_ops->slot_size;
+	int bcn_addr = MT_BEACON_BASE + (bcn_len * dev->beacon_data_count);
 	int ret = 0;
-	int i;
-
-	/* Prevent corrupt transmissions during update */
-	mt76_set(dev, MT_BCN_BYPASS_MASK, BIT(bcn_idx));
 
 	if (skb) {
-		ret = mt76x02_write_beacon(dev, beacon_addr, skb);
+		ret = mt76x02_write_beacon(dev, bcn_addr, skb);
 		if (!ret)
-			dev->beacon_data_mask |= BIT(bcn_idx);
-	} else {
-		dev->beacon_data_mask &= ~BIT(bcn_idx);
+			dev->beacon_data_count++;
 	}
 
-	mt76_wr(dev, MT_BCN_BYPASS_MASK, 0xff00 | ~dev->beacon_data_mask);
-
+	dev_kfree_skb(skb);
 	return ret;
 }
-
-int mt76x02_mac_set_beacon(struct mt76x02_dev *dev, u8 vif_idx,
-			   struct sk_buff *skb)
-{
-	bool force_update = false;
-	int bcn_idx = 0;
-	int i;
-
-	for (i = 0; i < ARRAY_SIZE(dev->beacons); i++) {
-		if (vif_idx == i) {
-			force_update = !!dev->beacons[i] ^ !!skb;
-			dev_kfree_skb(dev->beacons[i]);
-			dev->beacons[i] = skb;
-			__mt76x02_mac_set_beacon(dev, bcn_idx, skb);
-		} else if (force_update && dev->beacons[i]) {
-			__mt76x02_mac_set_beacon(dev, bcn_idx,
-						 dev->beacons[i]);
-		}
-
-		bcn_idx += !!dev->beacons[i];
-	}
-
-	for (i = bcn_idx; i < ARRAY_SIZE(dev->beacons); i++) {
-		if (!(dev->beacon_data_mask & BIT(i)))
-			break;
-
-		__mt76x02_mac_set_beacon(dev, i, NULL);
-	}
-
-	mt76_rmw_field(dev, MT_MAC_BSSID_DW1, MT_MAC_BSSID_DW1_MBEACON_N,
-		       bcn_idx - 1);
-	return 0;
-}
 EXPORT_SYMBOL_GPL(mt76x02_mac_set_beacon);
 
 void mt76x02_mac_set_beacon_enable(struct mt76x02_dev *dev,
@@ -114,7 +73,6 @@ void mt76x02_mac_set_beacon_enable(struct mt76x02_dev *dev,
 		dev->mt76.beacon_mask |= BIT(mvif->idx);
 	} else {
 		dev->mt76.beacon_mask &= ~BIT(mvif->idx);
-		mt76x02_mac_set_beacon(dev, mvif->idx, NULL);
 	}
 
 	if (!!old_mask == !!dev->mt76.beacon_mask)
@@ -180,7 +138,7 @@ mt76x02_update_beacon_iter(void *priv, u8 *mac, struct ieee80211_vif *vif)
 	if (!skb)
 		return;
 
-	mt76x02_mac_set_beacon(dev, mvif->idx, skb);
+	mt76x02_mac_set_beacon(dev, skb);
 }
 EXPORT_SYMBOL_GPL(mt76x02_update_beacon_iter);
 

drivers/net/wireless/mediatek/mt76/mt76x02_mac.c

@@ -741,6 +741,8 @@ void mt76x02_mac_setaddr(struct mt76x02_dev *dev, const u8 *addr)
 		get_unaligned_le16(dev->mt76.macaddr + 4) |
 		FIELD_PREP(MT_MAC_BSSID_DW1_MBSS_MODE, 3) | /* 8 APs + 8 STAs */
 		MT_MAC_BSSID_DW1_MBSS_LOCAL_BIT);
+	/* enable 7 additional beacon slots and control them with bypass mask */
+	mt76_rmw_field(dev, MT_MAC_BSSID_DW1, MT_MAC_BSSID_DW1_MBEACON_N, 7);
 
 	for (i = 0; i < 16; i++)
 		mt76x02_mac_set_bssid(dev, i, null_addr);

drivers/net/wireless/mediatek/mt76/mt76x02_mac.h

@@ -201,8 +201,7 @@ void mt76x02_mac_work(struct work_struct *work);
 
 void mt76x02_mac_cc_reset(struct mt76x02_dev *dev);
 void mt76x02_mac_set_bssid(struct mt76x02_dev *dev, u8 idx, const u8 *addr);
-int mt76x02_mac_set_beacon(struct mt76x02_dev *dev, u8 vif_idx,
-			   struct sk_buff *skb);
+int mt76x02_mac_set_beacon(struct mt76x02_dev *dev, struct sk_buff *skb);
 void mt76x02_mac_set_beacon_enable(struct mt76x02_dev *dev,
 				   struct ieee80211_vif *vif, bool enable);
 

drivers/net/wireless/mediatek/mt76/mt76x02_mmio.c

@@ -24,10 +24,17 @@ static void mt76x02_pre_tbtt_tasklet(unsigned long arg)
 
 	mt76x02_resync_beacon_timer(dev);
 
+	/* Prevent corrupt transmissions during update */
+	mt76_set(dev, MT_BCN_BYPASS_MASK, 0xffff);
+	dev->beacon_data_count = 0;
+
 	ieee80211_iterate_active_interfaces_atomic(mt76_hw(dev),
 		IEEE80211_IFACE_ITER_RESUME_ALL,
 		mt76x02_update_beacon_iter, dev);
 
+	mt76_wr(dev, MT_BCN_BYPASS_MASK,
+		0xff00 | ~(0xff00 >> dev->beacon_data_count));
+
 	mt76_csa_check(&dev->mt76);
 
 	if (dev->mt76.csa_complete)

drivers/net/wireless/mediatek/mt76/mt76x02_usb_core.c

@@ -208,6 +208,10 @@ static void mt76x02u_pre_tbtt_work(struct work_struct *work)
 
 	mt76x02_resync_beacon_timer(dev);
 
+	/* Prevent corrupt transmissions during update */
+	mt76_set(dev, MT_BCN_BYPASS_MASK, 0xffff);
+	dev->beacon_data_count = 0;
+
 	ieee80211_iterate_active_interfaces(mt76_hw(dev),
 		IEEE80211_IFACE_ITER_RESUME_ALL,
 		mt76x02_update_beacon_iter, dev);
@@ -217,9 +221,12 @@ static void mt76x02u_pre_tbtt_work(struct work_struct *work)
 
 	for (i = nbeacons; i < N_BCN_SLOTS; i++) {
 		skb = __skb_dequeue(&data.q);
-		mt76x02_mac_set_beacon(dev, i, skb);
+		mt76x02_mac_set_beacon(dev, skb);
 	}
 
+	mt76_wr(dev, MT_BCN_BYPASS_MASK,
+		0xff00 | ~(0xff00 >> dev->beacon_data_count));
+
 	mt76x02u_restart_pre_tbtt_timer(dev);
 }
 
@@ -244,20 +251,11 @@ static void mt76x02u_pre_tbtt_enable(struct mt76x02_dev *dev, bool en)
 
 static void mt76x02u_beacon_enable(struct mt76x02_dev *dev, bool en)
 {
-	int i;
-
 	if (WARN_ON_ONCE(!dev->mt76.beacon_int))
 		return;
 
-	if (en) {
+	if (en)
 		mt76x02u_start_pre_tbtt_timer(dev);
-	} else {
-		/* Timer is already stopped, only clean up
-		 * PS buffered frames if any.
-		 */
-		for (i = 0; i < N_BCN_SLOTS; i++)
-			mt76x02_mac_set_beacon(dev, i, NULL);
-	}
 }
 
 void mt76x02u_init_beacon_config(struct mt76x02_dev *dev)