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>

10 files changed, 114 insertions, 93 deletions

diff --git a/net/mac80211/Kconfig b/net/mac80211/Kconfig
index a24b459dd45a..590e00b2766c 100644
--- a/net/mac80211/Kconfig
+++ b/net/mac80211/Kconfig
@@ -7,11 +7,23 @@ config MAC80211
         select CRC32
         select WIRELESS_EXT
         select CFG80211
-        select NET_SCH_FIFO
         ---help---
           This option enables the hardware independent IEEE 802.11
           networking stack.
 
+config MAC80211_QOS
+        def_bool y
+        depends on MAC80211
+        depends on NET_SCHED
+        depends on NETDEVICES_MULTIQUEUE
+
+comment "QoS/HT support disabled"
+        depends on MAC80211 && !MAC80211_QOS
+comment "QoS/HT support needs CONFIG_NET_SCHED"
+        depends on MAC80211 && !NET_SCHED
+comment "QoS/HT support needs CONFIG_NETDEVICES_MULTIQUEUE"
+        depends on MAC80211 && !NETDEVICES_MULTIQUEUE
+
 menu "Rate control algorithm selection"
         depends on MAC80211 != n
 
diff --git a/net/mac80211/Makefile b/net/mac80211/Makefile
index 4e5847fd316c..1d2a4e010e5c 100644
--- a/net/mac80211/Makefile
+++ b/net/mac80211/Makefile
@@ -29,7 +29,7 @@ mac80211-y := \
         event.o
 
 mac80211-$(CONFIG_MAC80211_LEDS) += led.o
-mac80211-$(CONFIG_NET_SCHED) += wme.o
+mac80211-$(CONFIG_MAC80211_QOS) += wme.o
 mac80211-$(CONFIG_MAC80211_DEBUGFS) += \
         debugfs.o \
         debugfs_sta.o \
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 86a861251e8c..7d614cdcefcb 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -594,7 +594,7 @@ struct ieee80211_local {
         struct sta_info *sta_hash[STA_HASH_SIZE];
         struct timer_list sta_cleanup;
 
-        unsigned long state[IEEE80211_MAX_QUEUES + IEEE80211_MAX_AMPDU_QUEUES];
+        unsigned long queues_pending[BITS_TO_LONGS(IEEE80211_MAX_QUEUES)];
         struct ieee80211_tx_stored_packet pending_packet[IEEE80211_MAX_QUEUES];
         struct tasklet_struct tx_pending_tasklet;
 
@@ -758,6 +758,15 @@ struct ieee80211_local {
 #endif
 };
 
+static inline int ieee80211_is_multiqueue(struct ieee80211_local *local)
+{
+#ifdef CONFIG_MAC80211_QOS
+        return netif_is_multiqueue(local->mdev);
+#else
+        return 0;
+#endif
+}
+
 /* this struct represents 802.11n's RA/TID combination */
 struct ieee80211_ra_tid {
         u8 ra[ETH_ALEN];
@@ -827,11 +836,6 @@ static inline struct ieee80211_hw *local_to_hw(
         return &local->hw;
 }
 
-enum ieee80211_link_state_t {
-        IEEE80211_LINK_STATE_XOFF = 0,
-        IEEE80211_LINK_STATE_PENDING,
-};
-
 struct sta_attribute {
         struct attribute attr;
         ssize_t (*show)(const struct sta_info *, char *buf);
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 3c64e42eb12e..984472702381 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -168,7 +168,7 @@ void ieee80211_if_set_type(struct net_device *dev, int type)
                 ifsta->flags |= IEEE80211_STA_CREATE_IBSS |
                         IEEE80211_STA_AUTO_BSSID_SEL |
                         IEEE80211_STA_AUTO_CHANNEL_SEL;
-                if (sdata->local->hw.queues >= 4)
+                if (ieee80211_num_regular_queues(&sdata->local->hw) >= 4)
                         ifsta->flags |= IEEE80211_STA_WMM_ENABLED;
 
                 msdata = IEEE80211_DEV_TO_SUB_IF(sdata->local->mdev);
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 8f1ff7ef1667..97d4a537ca2f 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -1634,12 +1634,32 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
         if (result < 0)
                 return result;
 
+        /*
+         * We use the number of queues for feature tests (QoS, HT) internally
+         * so restrict them appropriately.
+         */
+#ifdef CONFIG_MAC80211_QOS
+        if (hw->queues > IEEE80211_MAX_QUEUES)
+                hw->queues = IEEE80211_MAX_QUEUES;
+        if (hw->ampdu_queues > IEEE80211_MAX_AMPDU_QUEUES)
+                hw->ampdu_queues = IEEE80211_MAX_AMPDU_QUEUES;
+        if (hw->queues < 4)
+                hw->ampdu_queues = 0;
+#else
+        hw->queues = 1;
+        hw->ampdu_queues = 0;
+#endif
+
         /* for now, mdev needs sub_if_data :/ */
-        mdev = alloc_netdev(sizeof(struct ieee80211_sub_if_data),
-                            "wmaster%d", ether_setup);
+        mdev = alloc_netdev_mq(sizeof(struct ieee80211_sub_if_data),
+                               "wmaster%d", ether_setup,
+                               ieee80211_num_queues(hw));
         if (!mdev)
                 goto fail_mdev_alloc;
 
+        if (ieee80211_num_queues(hw) > 1)
+                mdev->features |= NETIF_F_MULTI_QUEUE;
+
         sdata = IEEE80211_DEV_TO_SUB_IF(mdev);
         mdev->ieee80211_ptr = &sdata->wdev;
         sdata->wdev.wiphy = local->hw.wiphy;
@@ -1728,11 +1748,6 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
                 goto fail_wep;
         }
 
-        if (hw->queues > IEEE80211_MAX_QUEUES)
-                hw->queues = IEEE80211_MAX_QUEUES;
-        if (hw->ampdu_queues > IEEE80211_MAX_AMPDU_QUEUES)
-                hw->ampdu_queues = IEEE80211_MAX_AMPDU_QUEUES;
-
         ieee80211_install_qdisc(local->mdev);
 
         /* add one default STA interface */
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index ef3149324d54..c24770cb02c5 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -255,7 +255,7 @@ struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata,
                  * sta_rx_agg_session_timer_expired for useage */
                 sta->timer_to_tid[i] = i;
                 /* tid to tx queue: initialize according to HW (0 is valid) */
-                sta->tid_to_tx_q[i] = local->hw.queues + local->hw.ampdu_queues;
+                sta->tid_to_tx_q[i] = ieee80211_num_queues(&local->hw);
                 /* rx */
                 sta->ampdu_mlme.tid_state_rx[i] = HT_AGG_STATE_IDLE;
                 sta->ampdu_mlme.tid_rx[i] = NULL;
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 */
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index d9109dee461f..4f7180b287da 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -331,17 +331,15 @@ void ieee80211_wake_queue(struct ieee80211_hw *hw, int queue)
 {
         struct ieee80211_local *local = hw_to_local(hw);
 
-        if (test_and_clear_bit(IEEE80211_LINK_STATE_XOFF,
-                               &local->state[queue])) {
-                if (test_bit(IEEE80211_LINK_STATE_PENDING,
-                             &local->state[queue]))
-                        tasklet_schedule(&local->tx_pending_tasklet);
-                else
-                        if (!ieee80211_qdisc_installed(local->mdev)) {
-                                if (queue == 0)
-                                        netif_wake_queue(local->mdev);
-                        } else
-                                __netif_schedule(local->mdev);
+        if (test_bit(queue, local->queues_pending)) {
+                tasklet_schedule(&local->tx_pending_tasklet);
+        } else {
+                if (ieee80211_is_multiqueue(local)) {
+                        netif_wake_subqueue(local->mdev, queue);
+                } else {
+                        WARN_ON(queue != 0);
+                        netif_wake_queue(local->mdev);
+                }
         }
 }
 EXPORT_SYMBOL(ieee80211_wake_queue);
@@ -350,9 +348,12 @@ void ieee80211_stop_queue(struct ieee80211_hw *hw, int queue)
 {
         struct ieee80211_local *local = hw_to_local(hw);
 
-        if (!ieee80211_qdisc_installed(local->mdev) && queue == 0)
+        if (ieee80211_is_multiqueue(local)) {
+                netif_stop_subqueue(local->mdev, queue);
+        } else {
+                WARN_ON(queue != 0);
                 netif_stop_queue(local->mdev);
-        set_bit(IEEE80211_LINK_STATE_XOFF, &local->state[queue]);
+        }
 }
 EXPORT_SYMBOL(ieee80211_stop_queue);
 
@@ -360,7 +361,7 @@ void ieee80211_stop_queues(struct ieee80211_hw *hw)
 {
         int i;
 
-        for (i = 0; i < hw->queues + hw->ampdu_queues; i++)
+        for (i = 0; i < ieee80211_num_queues(hw); i++)
                 ieee80211_stop_queue(hw, i);
 }
 EXPORT_SYMBOL(ieee80211_stop_queues);
diff --git a/net/mac80211/wme.c b/net/mac80211/wme.c
index 477690f4dca7..14a9ff10a1e9 100644
--- a/net/mac80211/wme.c
+++ b/net/mac80211/wme.c
@@ -158,7 +158,7 @@ static int wme_qdiscop_enqueue(struct sk_buff *skb, struct Qdisc* qd)
         u8 tid;
 
         if (info->flags & IEEE80211_TX_CTL_REQUEUE) {
-                queue = info->queue;
+                queue = skb_get_queue_mapping(skb);
                 rcu_read_lock();
                 sta = sta_info_get(local, hdr->addr1);
                 tid = skb->priority & QOS_CONTROL_TAG1D_MASK;
@@ -219,7 +219,7 @@ static int wme_qdiscop_enqueue(struct sk_buff *skb, struct Qdisc* qd)
                         err = NET_XMIT_DROP;
         } else {
                 tid = skb->priority & QOS_CONTROL_TAG1D_MASK;
-                info->queue = (unsigned int) queue;
+                skb_set_queue_mapping(skb, queue);
                 qdisc = q->queues[queue];
                 err = qdisc->enqueue(skb, qdisc);
                 if (err == NET_XMIT_SUCCESS) {
@@ -240,12 +240,11 @@ static int wme_qdiscop_enqueue(struct sk_buff *skb, struct Qdisc* qd)
 static int wme_qdiscop_requeue(struct sk_buff *skb, struct Qdisc* qd)
 {
         struct ieee80211_sched_data *q = qdisc_priv(qd);
-        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
         struct Qdisc *qdisc;
         int err;
 
         /* we recorded which queue to use earlier! */
-        qdisc = q->queues[info->queue];
+        qdisc = q->queues[skb_get_queue_mapping(skb)];
 
         if ((err = qdisc->ops->requeue(skb, qdisc)) == 0) {
                 qd->q.qlen++;
@@ -269,11 +268,8 @@ static struct sk_buff *wme_qdiscop_dequeue(struct Qdisc* qd)
         /* check all the h/w queues in numeric/priority order */
         for (queue = 0; queue < QD_NUM(hw); queue++) {
                 /* see if there is room in this hardware queue */
-                if ((test_bit(IEEE80211_LINK_STATE_XOFF,
-                                &local->state[queue])) ||
-                    (test_bit(IEEE80211_LINK_STATE_PENDING,
-                                &local->state[queue])) ||
-                         (!test_bit(queue, q->qdisc_pool)))
+                if (__netif_subqueue_stopped(local->mdev, queue) ||
+                    !test_bit(queue, q->qdisc_pool))
                         continue;
 
                 /* there is space - try and get a frame */
diff --git a/net/mac80211/wme.h b/net/mac80211/wme.h
index fcc6b05508cc..bbdb53344817 100644
--- a/net/mac80211/wme.h
+++ b/net/mac80211/wme.h
@@ -31,7 +31,7 @@ static inline int WLAN_FC_IS_QOS_DATA(u16 fc)
         return (fc & 0x8C) == 0x88;
 }
 
-#ifdef CONFIG_NET_SCHED
+#ifdef CONFIG_MAC80211_QOS
 void ieee80211_install_qdisc(struct net_device *dev);
 int ieee80211_qdisc_installed(struct net_device *dev);
 int ieee80211_ht_agg_queue_add(struct ieee80211_local *local,