mac80211: Tx frame latency statistics

Measure TX latency and jitter statistics per station per TID.
These Measurements are disabled by default and can be enabled
via debugfs.

Features included for each station's TID:

1. Keep count of the maximum and average latency of Tx frames.
2. Keep track of many frames arrived in a specific time range
   (need to enable through debugfs and configure the bins ranges)

Signed-off-by: Matti Gottlieb <matti.gottlieb@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index a2c9a4c45aa3..0218caf5c14a 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -220,6 +220,25 @@ struct sta_ampdu_mlme {
 	u8 dialog_token_allocator;
 };
 
+/*
+ * struct ieee80211_tx_latency_stat - Tx latency statistics
+ *
+ * Measures TX latency and jitter for a station per TID.
+ *
+ * @max: worst case latency
+ * @sum: sum of all latencies
+ * @counter: amount of Tx frames sent from interface
+ * @bins: each bin counts how many frames transmitted within a certain
+ * latency range. when disabled it is NULL.
+ * @bin_count: amount of bins.
+ */
+struct ieee80211_tx_latency_stat {
+	u32 max;
+	u32 sum;
+	u32 counter;
+	u32 *bins;
+	u32 bin_count;
+};
 
 /**
  * struct sta_info - STA information
@@ -276,6 +295,7 @@ struct sta_ampdu_mlme {
  * @tid_seq: per-TID sequence numbers for sending to this STA
  * @ampdu_mlme: A-MPDU state machine state
  * @timer_to_tid: identity mapping to ID timers
+ * @tx_lat: Tx latency statistics
  * @llid: Local link ID
  * @plid: Peer link ID
  * @reason: Cancel reason on PLINK_HOLDING state
@@ -385,6 +405,8 @@ struct sta_info {
 	struct sta_ampdu_mlme ampdu_mlme;
 	u8 timer_to_tid[IEEE80211_NUM_TIDS];
 
+	struct ieee80211_tx_latency_stat *tx_lat;
+
 #ifdef CONFIG_MAC80211_MESH
 	/*
 	 * Mesh peer link attributes