iwlwifi: A-MPDU Tx activation by load measures

This patch gives a heuristic for activation of the A-MPDU Tx.
As the rate scaling is rate aware, it now also measures estimated load, and
sends A-MPDU activation after a threshold has been met.

Signed-off-by: Ron Rindjunsky <ron.rindjunsky@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 186 insertions, 18 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-4965-rs.c b/drivers/net/wireless/iwlwifi/iwl-4965-rs.c
index f4f2497646bd..660671f17a3b 100644
--- a/drivers/net/wireless/iwlwifi/iwl-4965-rs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-4965-rs.c
@@ -83,7 +83,7 @@ struct iwl4965_rate_scale_data {
 /**
  * struct iwl4965_scale_tbl_info -- tx params and success history for all rates
  *
- * There are two of these in struct iwl_rate_scale_priv,
+ * There are two of these in struct iwl4965_lq_sta,
  * one for "active", and one for "search".
  */
 struct iwl4965_scale_tbl_info {
@@ -98,8 +98,23 @@ struct iwl4965_scale_tbl_info {
         struct iwl4965_rate_scale_data win[IWL_RATE_COUNT]; /* rate histories */
 };
 
+#ifdef CONFIG_IWL4965_HT
+
+struct iwl4965_traffic_load {
+        unsigned long time_stamp;       /* age of the oldest statistics */
+        u32 packet_count[TID_QUEUE_MAX_SIZE];   /* packet count in this time
+                                                 * slice */
+        u32 total;                      /* total num of packets during the
+                                         * last TID_MAX_TIME_DIFF */
+        u8 queue_count;                 /* number of queues that has
+                                         * been used since the last cleanup */
+        u8 head;                        /* start of the circular buffer */
+};
+
+#endif /* CONFIG_IWL4965_HT */
+
 /**
- * struct iwl_rate_scale_priv -- driver's rate scaling private structure
+ * struct iwl4965_lq_sta -- driver's rate scaling private structure
  *
  * Pointer to this gets passed back and forth between driver and mac80211.
  */
@@ -136,9 +151,16 @@ struct iwl4965_lq_sta {
 
         struct iwl4965_link_quality_cmd lq;
         struct iwl4965_scale_tbl_info lq_info[LQ_SIZE]; /* "active", "search" */
+#ifdef CONFIG_IWL4965_HT
+        struct iwl4965_traffic_load load[TID_MAX_LOAD_COUNT];
+        u8 tx_agg_tid_en;
+#endif
 #ifdef CONFIG_MAC80211_DEBUGFS
         struct dentry *rs_sta_dbgfs_scale_table_file;
         struct dentry *rs_sta_dbgfs_stats_table_file;
+#ifdef CONFIG_IWL4965_HT
+        struct dentry *rs_sta_dbgfs_tx_agg_tid_en_file;
+#endif
         struct iwl4965_rate dbg_fixed;
         struct iwl4965_priv *drv;
 #endif
@@ -269,6 +291,135 @@ static void rs_rate_scale_clear_window(struct iwl4965_rate_scale_data *window)
         window->stamp = 0;
 }
 
+#ifdef CONFIG_IWL4965_HT
+/*
+ *      removes the old data from the statistics. All data that is older than
+ *      TID_MAX_TIME_DIFF, will be deleted.
+ */
+static void rs_tl_rm_old_stats(struct iwl4965_traffic_load *tl, u32 curr_time)
+{
+        /* The oldest age we want to keep */
+        u32 oldest_time = curr_time - TID_MAX_TIME_DIFF;
+
+        while (tl->queue_count &&
+               (tl->time_stamp < oldest_time)) {
+                tl->total -= tl->packet_count[tl->head];
+                tl->packet_count[tl->head] = 0;
+                tl->time_stamp += TID_QUEUE_CELL_SPACING;
+                tl->queue_count--;
+                tl->head++;
+                if (tl->head >= TID_QUEUE_MAX_SIZE)
+                        tl->head = 0;
+        }
+}
+
+/*
+ *      increment traffic load value for tid and also remove
+ *      any old values if passed the certain time period
+ */
+static void rs_tl_add_packet(struct iwl4965_lq_sta *lq_data, u8 tid)
+{
+        u32 curr_time = jiffies_to_msecs(jiffies);
+        u32 time_diff;
+        s32 index;
+        struct iwl4965_traffic_load *tl = NULL;
+
+        if (tid >= TID_MAX_LOAD_COUNT)
+                return;
+
+        tl = &lq_data->load[tid];
+
+        curr_time -= curr_time % TID_ROUND_VALUE;
+
+        /* Happens only for the first packet. Initialize the data */
+        if (!(tl->queue_count)) {
+                tl->total = 1;
+                tl->time_stamp = curr_time;
+                tl->queue_count = 1;
+                tl->head = 0;
+                tl->packet_count[0] = 1;
+                return;
+        }
+
+        time_diff = TIME_WRAP_AROUND(tl->time_stamp, curr_time);
+        index = time_diff / TID_QUEUE_CELL_SPACING;
+
+        /* The history is too long: remove data that is older than */
+        /* TID_MAX_TIME_DIFF */
+        if (index >= TID_QUEUE_MAX_SIZE)
+                rs_tl_rm_old_stats(tl, curr_time);
+
+        index = (tl->head + index) % TID_QUEUE_MAX_SIZE;
+        tl->packet_count[index] = tl->packet_count[index] + 1;
+        tl->total = tl->total + 1;
+
+        if ((index + 1) > tl->queue_count)
+                tl->queue_count = index + 1;
+}
+
+/*
+        get the traffic load value for tid
+*/
+static u32 rs_tl_get_load(struct iwl4965_lq_sta *lq_data, u8 tid)
+{
+        u32 curr_time = jiffies_to_msecs(jiffies);
+        u32 time_diff;
+        s32 index;
+        struct iwl4965_traffic_load *tl = NULL;
+
+        if (tid >= TID_MAX_LOAD_COUNT)
+                return 0;
+
+        tl = &(lq_data->load[tid]);
+
+        curr_time -= curr_time % TID_ROUND_VALUE;
+
+        if (!(tl->queue_count))
+                return 0;
+
+        time_diff = TIME_WRAP_AROUND(tl->time_stamp, curr_time);
+        index = time_diff / TID_QUEUE_CELL_SPACING;
+
+        /* The history is too long: remove data that is older than */
+        /* TID_MAX_TIME_DIFF */
+        if (index >= TID_QUEUE_MAX_SIZE)
+                rs_tl_rm_old_stats(tl, curr_time);
+
+        return tl->total;
+}
+
+static void rs_tl_turn_on_agg_for_tid(struct iwl4965_priv *priv,
+                                struct iwl4965_lq_sta *lq_data, u8 tid,
+                                struct sta_info *sta)
+{
+        unsigned long state;
+        DECLARE_MAC_BUF(mac);
+
+        spin_lock_bh(&sta->ampdu_mlme.ampdu_tx);
+        state = sta->ampdu_mlme.tid_tx[tid].state;
+        spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
+
+        if (state == HT_AGG_STATE_IDLE &&
+            rs_tl_get_load(lq_data, tid) > IWL_AGG_LOAD_THRESHOLD) {
+                IWL_DEBUG_HT("Starting Tx agg: STA: %s tid: %d\n",
+                                print_mac(mac, sta->addr), tid);
+                ieee80211_start_tx_ba_session(priv->hw, sta->addr, tid);
+        }
+}
+
+static void rs_tl_turn_on_agg(struct iwl4965_priv *priv, u8 tid,
+                                struct iwl4965_lq_sta *lq_data,
+                                struct sta_info *sta)
+{
+        if ((tid < TID_MAX_LOAD_COUNT))
+                rs_tl_turn_on_agg_for_tid(priv, lq_data, tid, sta);
+        else if (tid == IWL_AGG_ALL_TID)
+                for (tid = 0; tid < TID_MAX_LOAD_COUNT; tid++)
+                        rs_tl_turn_on_agg_for_tid(priv, lq_data, tid, sta);
+}
+
+#endif /* CONFIG_IWLWIFI_HT */
+
 /**
  * rs_collect_tx_data - Update the success/failure sliding window
  *
@@ -1134,7 +1285,7 @@ static int rs_switch_to_mimo(struct iwl4965_priv *priv,
         return 0;
 #else
         return -1;
-#endif                          /*CONFIG_IWL4965_HT */
+#endif  /*CONFIG_IWL4965_HT */
 }
 
 /*
@@ -1197,7 +1348,7 @@ static int rs_switch_to_siso(struct iwl4965_priv *priv,
 #else
         return -1;
 
-#endif                          /*CONFIG_IWL4965_HT */
+#endif  /*CONFIG_IWL4965_HT */
 }
 
 /*
@@ -1354,6 +1505,7 @@ static int rs_move_siso_to_other(struct iwl4965_priv *priv,
                         break;
                 case IWL_SISO_SWITCH_GI:
                         IWL_DEBUG_HT("LQ: SISO SWITCH TO GI\n");
+
                         memcpy(search_tbl, tbl, sz);
                         search_tbl->action = 0;
                         if (search_tbl->is_SGI)
@@ -1419,6 +1571,7 @@ static int rs_move_mimo_to_other(struct iwl4965_priv *priv,
                 case IWL_MIMO_SWITCH_ANTENNA_B:
                         IWL_DEBUG_HT("LQ: MIMO SWITCH TO SISO\n");
 
+
                         /* Set up new search table for SISO */
                         memcpy(search_tbl, tbl, sz);
                         search_tbl->lq_type = LQ_SISO;
@@ -1603,6 +1756,10 @@ static void rs_rate_scale_perform(struct iwl4965_priv *priv,
         u8 active_tbl = 0;
         u8 done_search = 0;
         u16 high_low;
+#ifdef CONFIG_IWL4965_HT
+        u8 tid = MAX_TID_COUNT;
+        __le16 *qc;
+#endif
 
         IWL_DEBUG_RATE("rate scale calculate new rate for skb\n");
 
@@ -1623,6 +1780,13 @@ static void rs_rate_scale_perform(struct iwl4965_priv *priv,
         }
         lq_sta = (struct iwl4965_lq_sta *)sta->rate_ctrl_priv;
 
+#ifdef CONFIG_IWL4965_HT
+        qc = ieee80211_get_qos_ctrl(hdr);
+        if (qc) {
+                tid = (u8)(le16_to_cpu(*qc) & 0xf);
+                rs_tl_add_packet(lq_sta, tid);
+        }
+#endif
         /*
          * Select rate-scale / modulation-mode table to work with in
          * the rest of this function:  "search" if searching for better
@@ -1943,15 +2107,14 @@ static void rs_rate_scale_perform(struct iwl4965_priv *priv,
                  * mode for a while before next round of mode comparisons. */
                 if (lq_sta->enable_counter &&
                     (lq_sta->action_counter >= IWL_ACTION_LIMIT)) {
-#ifdef CONFIG_IWL4965_HT_AGG
-                        /* If appropriate, set up aggregation! */
-                        if ((lq_sta->last_tpt > TID_AGG_TPT_THREHOLD) &&
-                            (priv->lq_mngr.agg_ctrl.auto_agg)) {
-                                priv->lq_mngr.agg_ctrl.tid_retry =
-                                    TID_ALL_SPECIFIED;
-                                schedule_work(&priv->agg_work);
+#ifdef CONFIG_IWL4965_HT
+                        if ((lq_sta->last_tpt > IWL_AGG_TPT_THREHOLD) &&
+                            (lq_sta->tx_agg_tid_en & (1 << tid)) &&
+                            (tid != MAX_TID_COUNT)) {
+                                IWL_DEBUG_HT("try to aggregate tid %d\n", tid);
+                                rs_tl_turn_on_agg(priv, tid, lq_sta, sta);
                         }
-#endif /*CONFIG_IWL4965_HT_AGG */
+#endif /*CONFIG_IWL4965_HT */
                         lq_sta->action_counter = 0;
                         rs_set_stay_in_table(0, lq_sta);
                 }
@@ -2209,6 +2372,8 @@ static void rs_rate_init(void *priv_rate, void *priv_sta,
         IWL_DEBUG_HT("SISO RATE 0x%X MIMO RATE 0x%X\n",
                      lq_sta->active_siso_rate,
                      lq_sta->active_mimo_rate);
+        /* as default allow aggregation for all tids */
+        lq_sta->tx_agg_tid_en = IWL_AGG_ALL_TID;
 #endif /*CONFIG_IWL4965_HT*/
 #ifdef CONFIG_MAC80211_DEBUGFS
         lq_sta->drv = priv;
@@ -2352,12 +2517,6 @@ static void rs_clear(void *priv_rate)
         IWL_DEBUG_RATE("enter\n");
 
         priv->lq_mngr.lq_ready = 0;
-#ifdef CONFIG_IWL4965_HT
-#ifdef CONFIG_IWL4965_HT_AGG
-        if (priv->lq_mngr.agg_ctrl.granted_ba)
-                iwl4965_turn_off_agg(priv, TID_ALL_SPECIFIED);
-#endif /*CONFIG_IWL4965_HT_AGG */
-#endif /* CONFIG_IWL4965_HT */
 
         IWL_DEBUG_RATE("leave\n");
 }
@@ -2524,6 +2683,12 @@ static void rs_add_debugfs(void *priv, void *priv_sta,
         lq_sta->rs_sta_dbgfs_stats_table_file =
                 debugfs_create_file("rate_stats_table", 0600, dir,
                         lq_sta, &rs_sta_dbgfs_stats_table_ops);
+#ifdef CONFIG_IWL4965_HT
+        lq_sta->rs_sta_dbgfs_tx_agg_tid_en_file =
+                debugfs_create_u8("tx_agg_tid_enable", 0600, dir,
+                &lq_sta->tx_agg_tid_en);
+#endif
+
 }
 
 static void rs_remove_debugfs(void *priv, void *priv_sta)
@@ -2531,6 +2696,9 @@ static void rs_remove_debugfs(void *priv, void *priv_sta)
         struct iwl4965_lq_sta *lq_sta = priv_sta;
         debugfs_remove(lq_sta->rs_sta_dbgfs_scale_table_file);
         debugfs_remove(lq_sta->rs_sta_dbgfs_stats_table_file);
+#ifdef CONFIG_IWL4965_HT
+        debugfs_remove(lq_sta->rs_sta_dbgfs_tx_agg_tid_en_file);
+#endif
 }
 #endif