mac80211/iwlwifi: move virtual A-MDPU queue bookkeeping to iwlwifi

This patch removes all the virtual A-MPDU-queue bookkeeping from
mac80211. Curiously, iwlwifi already does its own bookkeeping, so
it doesn't require much changes except where it needs to handle
starting and stopping the queues in mac80211.

To handle the queue stop/wake properly, we rewrite the software
queue number for aggregation frames and internally to iwlwifi keep
track of the queues that map into the same AC queue, and only talk
to mac80211 about the AC queue. The implementation requires calling
two new functions, iwl_stop_queue and iwl_wake_queue instead of the
mac80211 counterparts.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Reinette Chattre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

8 files changed, 71 insertions, 16 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-3945.c b/drivers/net/wireless/iwlwifi/iwl-3945.c
index d03f5534afe..2399328e8de 100644
--- a/drivers/net/wireless/iwlwifi/iwl-3945.c
+++ b/drivers/net/wireless/iwlwifi/iwl-3945.c
@@ -293,7 +293,7 @@ static void iwl3945_tx_queue_reclaim(struct iwl_priv *priv,
 	if (iwl_queue_space(q) > q->low_mark && (txq_id >= 0) &&
 			(txq_id != IWL_CMD_QUEUE_NUM) &&
 			priv->mac80211_registered)
-		ieee80211_wake_queue(priv->hw, txq_id);
+		iwl_wake_queue(priv, txq_id);
 }
 
 /**
diff --git a/drivers/net/wireless/iwlwifi/iwl-4965.c b/drivers/net/wireless/iwlwifi/iwl-4965.c
index bd0140be774..847a6220c5e 100644
--- a/drivers/net/wireless/iwlwifi/iwl-4965.c
+++ b/drivers/net/wireless/iwlwifi/iwl-4965.c
@@ -2178,10 +2178,9 @@ static void iwl4965_rx_reply_tx(struct iwl_priv *priv,
 			    (iwl_queue_space(&txq->q) > txq->q.low_mark) &&
 			    (agg->state != IWL_EMPTYING_HW_QUEUE_DELBA)) {
 				if (agg->state == IWL_AGG_OFF)
-					ieee80211_wake_queue(priv->hw, txq_id);
+					iwl_wake_queue(priv, txq_id);
 				else
-					ieee80211_wake_queue(priv->hw,
-							     txq->swq_id);
+					iwl_wake_queue(priv, txq->swq_id);
 			}
 		}
 	} else {
@@ -2205,7 +2204,7 @@ static void iwl4965_rx_reply_tx(struct iwl_priv *priv,
 
 		if (priv->mac80211_registered &&
 		    (iwl_queue_space(&txq->q) > txq->q.low_mark))
-			ieee80211_wake_queue(priv->hw, txq_id);
+			iwl_wake_queue(priv, txq_id);
 	}
 
 	if (qc && likely(sta_id != IWL_INVALID_STATION))
diff --git a/drivers/net/wireless/iwlwifi/iwl-5000.c b/drivers/net/wireless/iwlwifi/iwl-5000.c
index a3d9a95a9b3..e5ca2511a81 100644
--- a/drivers/net/wireless/iwlwifi/iwl-5000.c
+++ b/drivers/net/wireless/iwlwifi/iwl-5000.c
@@ -1295,10 +1295,9 @@ static void iwl5000_rx_reply_tx(struct iwl_priv *priv,
 			    (iwl_queue_space(&txq->q) > txq->q.low_mark) &&
 			    (agg->state != IWL_EMPTYING_HW_QUEUE_DELBA)) {
 				if (agg->state == IWL_AGG_OFF)
-					ieee80211_wake_queue(priv->hw, txq_id);
+					iwl_wake_queue(priv, txq_id);
 				else
-					ieee80211_wake_queue(priv->hw,
-							     txq->swq_id);
+					iwl_wake_queue(priv, txq->swq_id);
 			}
 		}
 	} else {
@@ -1324,7 +1323,7 @@ static void iwl5000_rx_reply_tx(struct iwl_priv *priv,
 
 		if (priv->mac80211_registered &&
 		    (iwl_queue_space(&txq->q) > txq->q.low_mark))
-			ieee80211_wake_queue(priv->hw, txq_id);
+			iwl_wake_queue(priv, txq_id);
 	}
 
 	if (ieee80211_is_data_qos(tx_resp->frame_ctrl))
diff --git a/drivers/net/wireless/iwlwifi/iwl-core.c b/drivers/net/wireless/iwlwifi/iwl-core.c
index 4b1298c2b0d..c54fb93e9d7 100644
--- a/drivers/net/wireless/iwlwifi/iwl-core.c
+++ b/drivers/net/wireless/iwlwifi/iwl-core.c
@@ -1309,9 +1309,6 @@ int iwl_setup_mac(struct iwl_priv *priv)
 
 	/* Default value; 4 EDCA QOS priorities */
 	hw->queues = 4;
-	/* queues to support 11n aggregation */
-	if (priv->cfg->sku & IWL_SKU_N)
-		hw->ampdu_queues = priv->cfg->mod_params->num_of_ampdu_queues;
 
 	hw->conf.beacon_int = 100;
 	hw->max_listen_interval = IWL_CONN_MAX_LISTEN_INTERVAL;
diff --git a/drivers/net/wireless/iwlwifi/iwl-dev.h b/drivers/net/wireless/iwlwifi/iwl-dev.h
index 0baae802282..ec9a13846ed 100644
--- a/drivers/net/wireless/iwlwifi/iwl-dev.h
+++ b/drivers/net/wireless/iwlwifi/iwl-dev.h
@@ -996,6 +996,12 @@ struct iwl_priv {
 	u8 key_mapping_key;
 	unsigned long ucode_key_table;
 
+	/* queue refcounts */
+#define IWL_MAX_HW_QUEUES	32
+	unsigned long queue_stopped[BITS_TO_LONGS(IWL_MAX_HW_QUEUES)];
+	/* for each AC */
+	atomic_t queue_stop_count[4];
+
 	/* Indication if ieee80211_ops->open has been called */
 	u8 is_open;
 
diff --git a/drivers/net/wireless/iwlwifi/iwl-helpers.h b/drivers/net/wireless/iwlwifi/iwl-helpers.h
index fb64d297dd4..a1328c3c81a 100644
--- a/drivers/net/wireless/iwlwifi/iwl-helpers.h
+++ b/drivers/net/wireless/iwlwifi/iwl-helpers.h
@@ -93,4 +93,56 @@ static inline int iwl_alloc_fw_desc(struct pci_dev *pci_dev,
 	return (desc->v_addr != NULL) ? 0 : -ENOMEM;
 }
 
+/*
+ * we have 8 bits used like this:
+ *
+ * 7 6 5 4 3 2 1 0
+ * | | | | | | | |
+ * | | | | | | +-+-------- AC queue (0-3)
+ * | | | | | |
+ * | +-+-+-+-+------------ HW A-MPDU queue
+ * |
+ * +---------------------- indicates agg queue
+ */
+static inline u8 iwl_virtual_agg_queue_num(u8 ac, u8 hwq)
+{
+	BUG_ON(ac > 3);   /* only have 2 bits */
+	BUG_ON(hwq > 31); /* only have 5 bits */
+
+	return 0x80 | (hwq << 2) | ac;
+}
+
+static inline void iwl_wake_queue(struct iwl_priv *priv, u8 queue)
+{
+	u8 ac = queue;
+	u8 hwq = queue;
+
+	if (queue & 0x80) {
+		ac = queue & 3;
+		hwq = (queue >> 2) & 0x1f;
+	}
+
+	if (test_and_clear_bit(hwq, priv->queue_stopped))
+		if (atomic_dec_return(&priv->queue_stop_count[ac]) <= 0)
+			ieee80211_wake_queue(priv->hw, ac);
+}
+
+static inline void iwl_stop_queue(struct iwl_priv *priv, u8 queue)
+{
+	u8 ac = queue;
+	u8 hwq = queue;
+
+	if (queue & 0x80) {
+		ac = queue & 3;
+		hwq = (queue >> 2) & 0x1f;
+	}
+
+	if (!test_and_set_bit(hwq, priv->queue_stopped))
+		if (atomic_inc_return(&priv->queue_stop_count[ac]) > 0)
+			ieee80211_stop_queue(priv->hw, ac);
+}
+
+#define ieee80211_stop_queue DO_NOT_USE_ieee80211_stop_queue
+#define ieee80211_wake_queue DO_NOT_USE_ieee80211_wake_queue
+
 #endif				/* __iwl_helpers_h__ */
diff --git a/drivers/net/wireless/iwlwifi/iwl-tx.c b/drivers/net/wireless/iwlwifi/iwl-tx.c
index b13862a598e..1f117a49c56 100644
--- a/drivers/net/wireless/iwlwifi/iwl-tx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-tx.c
@@ -763,8 +763,10 @@ int iwl_tx_skb(struct iwl_priv *priv, struct sk_buff *skb)
 		hdr->seq_ctrl |= cpu_to_le16(seq_number);
 		seq_number += 0x10;
 		/* aggregation is on for this <sta,tid> */
-		if (info->flags & IEEE80211_TX_CTL_AMPDU)
+		if (info->flags & IEEE80211_TX_CTL_AMPDU) {
 			txq_id = priv->stations[sta_id].tid[tid].agg.txq_id;
+			swq_id = iwl_virtual_agg_queue_num(swq_id, txq_id);
+		}
 		priv->stations[sta_id].tid[tid].tfds_in_queue++;
 	}
 
@@ -895,7 +897,7 @@ int iwl_tx_skb(struct iwl_priv *priv, struct sk_buff *skb)
 			iwl_txq_update_write_ptr(priv, txq);
 			spin_unlock_irqrestore(&priv->lock, flags);
 		} else {
-			ieee80211_stop_queue(priv->hw, txq->swq_id);
+			iwl_stop_queue(priv, txq->swq_id);
 		}
 	}
 
@@ -1433,7 +1435,7 @@ void iwl_rx_reply_compressed_ba(struct iwl_priv *priv,
 		if ((iwl_queue_space(&txq->q) > txq->q.low_mark) &&
 		    priv->mac80211_registered &&
 		    (agg->state != IWL_EMPTYING_HW_QUEUE_DELBA))
-			ieee80211_wake_queue(priv->hw, txq->swq_id);
+			iwl_wake_queue(priv, txq->swq_id);
 
 		iwl_txq_check_empty(priv, sta_id, tid, scd_flow);
 	}
diff --git a/drivers/net/wireless/iwlwifi/iwl3945-base.c b/drivers/net/wireless/iwlwifi/iwl3945-base.c
index ede29b6c4dc..a71b08ca7c7 100644
--- a/drivers/net/wireless/iwlwifi/iwl3945-base.c
+++ b/drivers/net/wireless/iwlwifi/iwl3945-base.c
@@ -1168,7 +1168,7 @@ static int iwl3945_tx_skb(struct iwl_priv *priv, struct sk_buff *skb)
 			spin_unlock_irqrestore(&priv->lock, flags);
 		}
 
-		ieee80211_stop_queue(priv->hw, skb_get_queue_mapping(skb));
+		iwl_stop_queue(priv, skb_get_queue_mapping(skb));
 	}
 
 	return 0;