mac80211: synchronously reserve TID per station

In TDLS (e.g., TDLS off-channel) there is a requirement for
some drivers to supply an unused TID between the AP and the
device to the FW, to allow sending PTI requests and to allow
the FW to aggregate on a specific TID for better throughput.

To ensure that the allocated TID is indeed unused, this patch
introduces an API for blocking the driver from TXing on that
TID.

Signed-off-by: Liad Kaufman <liad.kaufman@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 39 insertions, 0 deletions

diff --git a/net/mac80211/wme.c b/net/mac80211/wme.c
index fdf52db95b33..9eb0aee9105b 100644
--- a/net/mac80211/wme.c
+++ b/net/mac80211/wme.c
@@ -53,6 +53,36 @@ static int wme_downgrade_ac(struct sk_buff *skb)
 	}
 }
 
+/**
+ * ieee80211_fix_reserved_tid - return the TID to use if this one is reserved
+ * @tid: the assumed-reserved TID
+ *
+ * Returns: the alternative TID to use, or 0 on error
+ */
+static inline u8 ieee80211_fix_reserved_tid(u8 tid)
+{
+	switch (tid) {
+	case 0:
+		return 3;
+	case 1:
+		return 2;
+	case 2:
+		return 1;
+	case 3:
+		return 0;
+	case 4:
+		return 5;
+	case 5:
+		return 4;
+	case 6:
+		return 7;
+	case 7:
+		return 6;
+	}
+
+	return 0;
+}
+
 static u16 ieee80211_downgrade_queue(struct ieee80211_sub_if_data *sdata,
 				     struct sta_info *sta, struct sk_buff *skb)
 {
@@ -77,6 +107,10 @@ static u16 ieee80211_downgrade_queue(struct ieee80211_sub_if_data *sdata,
 		}
 	}
 
+	/* Check to see if this is a reserved TID */
+	if (sta && sta->reserved_tid == skb->priority)
+		skb->priority = ieee80211_fix_reserved_tid(skb->priority);
+
 	/* look up which queue to use for frames with this 1d tag */
 	return ieee802_1d_to_ac[skb->priority];
 }
@@ -143,6 +177,11 @@ u16 ieee80211_select_queue(struct ieee80211_sub_if_data *sdata,
 		break;
 #endif
 	case NL80211_IFTYPE_STATION:
+		/* might be a TDLS station */
+		sta = sta_info_get(sdata, skb->data);
+		if (sta)
+			qos = sta->sta.wme;
+
 		ra = sdata->u.mgd.bssid;
 		break;
 	case NL80211_IFTYPE_ADHOC: