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>

1 files changed, 52 insertions, 0 deletions

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__ */