mac80211: use multi-queue master netdevice

This patch updates mac80211 and drivers to be multi-queue aware and
use that instead of the internal queue mapping. Also does a number
of cleanups in various pieces of the code that fall out and reduces
internal mac80211 state size.

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

1 files changed, 45 insertions, 52 deletions

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 6268bbca148e..9273651d3d7c 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -213,18 +213,6 @@ static u16 ieee80211_duration(struct ieee80211_tx_data *tx, int group_addr,
         return dur;
 }
 
-static inline int __ieee80211_queue_stopped(const struct ieee80211_local *local,
-                                            int queue)
-{
-        return test_bit(IEEE80211_LINK_STATE_XOFF, &local->state[queue]);
-}
-
-static inline int __ieee80211_queue_pending(const struct ieee80211_local *local,
-                                            int queue)
-{
-        return test_bit(IEEE80211_LINK_STATE_PENDING, &local->state[queue]);
-}
-
 static int inline is_ieee80211_device(struct net_device *dev,
                                       struct net_device *master)
 {
@@ -680,7 +668,8 @@ ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx)
          * etc.
          */
         if (WARN_ON(tx->flags & IEEE80211_TX_CTL_AMPDU ||
-                    IEEE80211_SKB_CB(tx->skb)->queue >= tx->local->hw.queues))
+                    skb_get_queue_mapping(tx->skb) >=
+                        ieee80211_num_regular_queues(&tx->local->hw)))
                 return TX_DROP;
 
         first = tx->skb;
@@ -1098,11 +1087,9 @@ static int __ieee80211_tx(struct ieee80211_local *local, struct sk_buff *skb,
         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
         int ret, i;
 
-        if (!ieee80211_qdisc_installed(local->mdev) &&
-            __ieee80211_queue_stopped(local, 0)) {
-                netif_stop_queue(local->mdev);
+        if (netif_subqueue_stopped(local->mdev, skb))
                 return IEEE80211_TX_AGAIN;
-        }
+
         if (skb) {
                 ieee80211_dump_frame(wiphy_name(local->hw.wiphy),
                                      "TX to low-level driver", skb);
@@ -1121,7 +1108,8 @@ static int __ieee80211_tx(struct ieee80211_local *local, struct sk_buff *skb,
                                          IEEE80211_TX_CTL_USE_CTS_PROTECT |
                                          IEEE80211_TX_CTL_CLEAR_PS_FILT |
                                          IEEE80211_TX_CTL_FIRST_FRAGMENT);
-                        if (__ieee80211_queue_stopped(local, info->queue))
+                        if (netif_subqueue_stopped(local->mdev,
+                                                   tx->extra_frag[i]))
                                 return IEEE80211_TX_FRAG_AGAIN;
                         if (i == tx->num_extra_frag) {
                                 info->tx_rate_idx = tx->last_frag_rate_idx;
@@ -1160,9 +1148,11 @@ static int ieee80211_tx(struct net_device *dev, struct sk_buff *skb)
         ieee80211_tx_result res = TX_DROP, res_prepare;
         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
         int ret, i;
-        int queue = info->queue;
+        u16 queue;
 
-        WARN_ON(__ieee80211_queue_pending(local, queue));
+        queue = skb_get_queue_mapping(skb);
+
+        WARN_ON(test_bit(queue, local->queues_pending));
 
         if (unlikely(skb->len < 10)) {
                 dev_kfree_skb(skb);
@@ -1233,28 +1223,28 @@ retry:
                  * queues, there's no reason for a driver to reject
                  * a frame there, warn and drop it.
                  */
-                if (WARN_ON(queue >= local->hw.queues))
+                if (WARN_ON(queue >= ieee80211_num_regular_queues(&local->hw)))
                         goto drop;
 
                 store = &local->pending_packet[queue];
 
                 if (ret == IEEE80211_TX_FRAG_AGAIN)
                         skb = NULL;
-                set_bit(IEEE80211_LINK_STATE_PENDING,
-                        &local->state[queue]);
+                set_bit(queue, local->queues_pending);
                 smp_mb();
-                /* When the driver gets out of buffers during sending of
-                 * fragments and calls ieee80211_stop_queue, there is
-                 * a small window between IEEE80211_LINK_STATE_XOFF and
-                 * IEEE80211_LINK_STATE_PENDING flags are set. If a buffer
+                /*
+                 * When the driver gets out of buffers during sending of
+                 * fragments and calls ieee80211_stop_queue, the netif
+                 * subqueue is stopped. There is, however, a small window
+                 * in which the PENDING bit is not yet set. If a buffer
                  * gets available in that window (i.e. driver calls
                  * ieee80211_wake_queue), we would end up with ieee80211_tx
-                 * called with IEEE80211_LINK_STATE_PENDING. Prevent this by
+                 * called with the PENDING bit still set. Prevent this by
                  * continuing transmitting here when that situation is
-                 * possible to have happened. */
-                if (!__ieee80211_queue_stopped(local, queue)) {
-                        clear_bit(IEEE80211_LINK_STATE_PENDING,
-                                  &local->state[queue]);
+                 * possible to have happened.
+                 */
+                if (!__netif_subqueue_stopped(local->mdev, queue)) {
+                        clear_bit(queue, local->queues_pending);
                         goto retry;
                 }
                 store->skb = skb;
@@ -1509,7 +1499,8 @@ int ieee80211_subif_start_xmit(struct sk_buff *skb,
         }
 
         /* receiver and we are QoS enabled, use a QoS type frame */
-        if (sta_flags & WLAN_STA_WME && local->hw.queues >= 4) {
+        if (sta_flags & WLAN_STA_WME &&
+            ieee80211_num_regular_queues(&local->hw) >= 4) {
                 fc |= IEEE80211_STYPE_QOS_DATA;
                 hdrlen += 2;
         }
@@ -1661,41 +1652,51 @@ int ieee80211_subif_start_xmit(struct sk_buff *skb,
         return ret;
 }
 
-/* helper functions for pending packets for when queues are stopped */
 
+/*
+ * ieee80211_clear_tx_pending may not be called in a context where
+ * it is possible that it packets could come in again.
+ */
 void ieee80211_clear_tx_pending(struct ieee80211_local *local)
 {
         int i, j;
         struct ieee80211_tx_stored_packet *store;
 
-        for (i = 0; i < local->hw.queues; i++) {
-                if (!__ieee80211_queue_pending(local, i))
+        for (i = 0; i < ieee80211_num_regular_queues(&local->hw); i++) {
+                if (!test_bit(i, local->queues_pending))
                         continue;
                 store = &local->pending_packet[i];
                 kfree_skb(store->skb);
                 for (j = 0; j < store->num_extra_frag; j++)
                         kfree_skb(store->extra_frag[j]);
                 kfree(store->extra_frag);
-                clear_bit(IEEE80211_LINK_STATE_PENDING, &local->state[i]);
+                clear_bit(i, local->queues_pending);
         }
 }
 
+/*
+ * Transmit all pending packets. Called from tasklet, locks master device
+ * TX lock so that no new packets can come in.
+ */
 void ieee80211_tx_pending(unsigned long data)
 {
         struct ieee80211_local *local = (struct ieee80211_local *)data;
         struct net_device *dev = local->mdev;
         struct ieee80211_tx_stored_packet *store;
         struct ieee80211_tx_data tx;
-        int i, ret, reschedule = 0;
+        int i, ret;
 
         netif_tx_lock_bh(dev);
-        for (i = 0; i < local->hw.queues; i++) {
-                if (__ieee80211_queue_stopped(local, i))
+        for (i = 0; i < ieee80211_num_regular_queues(&local->hw); i++) {
+                /* Check that this queue is ok */
+                if (__netif_subqueue_stopped(local->mdev, i))
                         continue;
-                if (!__ieee80211_queue_pending(local, i)) {
-                        reschedule = 1;
+
+                if (!test_bit(i, local->queues_pending)) {
+                        ieee80211_wake_queue(&local->hw, i);
                         continue;
                 }
+
                 store = &local->pending_packet[i];
                 tx.extra_frag = store->extra_frag;
                 tx.num_extra_frag = store->num_extra_frag;
@@ -1708,19 +1709,11 @@ void ieee80211_tx_pending(unsigned long data)
                         if (ret == IEEE80211_TX_FRAG_AGAIN)
                                 store->skb = NULL;
                 } else {
-                        clear_bit(IEEE80211_LINK_STATE_PENDING,
-                                  &local->state[i]);
-                        reschedule = 1;
+                        clear_bit(i, local->queues_pending);
+                        ieee80211_wake_queue(&local->hw, i);
                 }
         }
         netif_tx_unlock_bh(dev);
-        if (reschedule) {
-                if (!ieee80211_qdisc_installed(dev)) {
-                        if (!__ieee80211_queue_stopped(local, 0))
-                                netif_wake_queue(dev);
-                } else
-                        netif_schedule(dev);
-        }
 }
 
 /* functions for drivers to get certain frames */