iwmc3200wifi: 802.11n Tx aggregation support

To support 802.11n Tx aggregation support with iwmc3200 wifi, we have to
handle the UMAC_CMD_OPCODE_STOP_RESUME_STA_TX notification from the UMAC.
Before sending an AddBA, the UMAC synchronizes with the host in order to
know what is the last Tx frame it's supposed to receive before it will be
able to start the actual aggregation session.
We thus have to keep track of the last sequence number that is scheduled
for transmission on a particular RAxTID, send an answer to the UMAC with
this sequence number. The UMAC then does the BA negociation and once it's
done with it sends a new UMAC_CMD_OPCODE_STOP_RESUME_STA_TX notification
to let us know that we can resume the Tx flow on the specified RAxTID.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Reviewed-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 66 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwmc3200wifi/rx.c b/drivers/net/wireless/iwmc3200wifi/rx.c
index bdb1d7e..72c27a3e 100644
--- a/drivers/net/wireless/iwmc3200wifi/rx.c
+++ b/drivers/net/wireless/iwmc3200wifi/rx.c
@@ -1087,6 +1087,71 @@ static int iwm_ntf_channel_info_list(struct iwm_priv *iwm, u8 *buf,
 	return 0;
 }
 
+static int iwm_ntf_stop_resume_tx(struct iwm_priv *iwm, u8 *buf,
+				  unsigned long buf_size,
+				  struct iwm_wifi_cmd *cmd)
+{
+	struct iwm_umac_notif_stop_resume_tx *stp_res_tx =
+		(struct iwm_umac_notif_stop_resume_tx *)buf;
+	struct iwm_sta_info *sta_info;
+	struct iwm_tid_info *tid_info;
+	u8 sta_id = STA_ID_N_COLOR_ID(stp_res_tx->sta_id);
+	u16 tid_msk = le16_to_cpu(stp_res_tx->stop_resume_tid_msk);
+	int bit, ret = 0;
+	bool stop = false;
+
+	IWM_DBG_NTF(iwm, DBG, "stop/resume notification:\n"
+		    "\tflags:       0x%x\n"
+		    "\tSTA id:      %d\n"
+		    "\tTID bitmask: 0x%x\n",
+		    stp_res_tx->flags, stp_res_tx->sta_id,
+		    stp_res_tx->stop_resume_tid_msk);
+
+	if (stp_res_tx->flags & UMAC_STOP_TX_FLAG)
+		stop = true;
+
+	sta_info = &iwm->sta_table[sta_id];
+	if (!sta_info->valid) {
+		IWM_ERR(iwm, "Stoping an invalid STA: %d %d\n",
+			sta_id, stp_res_tx->sta_id);
+		return -EINVAL;
+	}
+
+	for_each_bit(bit, (unsigned long *)&tid_msk, IWM_UMAC_TID_NR) {
+		tid_info = &sta_info->tid_info[bit];
+
+		mutex_lock(&tid_info->mutex);
+		tid_info->stopped = stop;
+		mutex_unlock(&tid_info->mutex);
+
+		if (!stop) {
+			struct iwm_tx_queue *txq;
+			u16 queue = iwm_tid_to_queue(bit);
+
+			if (queue < 0)
+				continue;
+
+			txq = &iwm->txq[queue];
+			/*
+			 * If we resume, we have to move our SKBs
+			 * back to the tx queue and queue some work.
+			 */
+			spin_lock_bh(&txq->lock);
+			skb_queue_splice_init(&txq->queue, &txq->stopped_queue);
+			spin_unlock_bh(&txq->lock);
+
+			queue_work(txq->wq, &txq->worker);
+		}
+
+	}
+
+	/* We send an ACK only for the stop case */
+	if (stop)
+		ret = iwm_send_umac_stop_resume_tx(iwm, stp_res_tx);
+
+	return ret;
+}
+
 static int iwm_ntf_wifi_if_wrapper(struct iwm_priv *iwm, u8 *buf,
 				   unsigned long buf_size,
 				   struct iwm_wifi_cmd *cmd)
@@ -1371,6 +1436,7 @@ static const iwm_handler iwm_umac_handlers[] =
 	[UMAC_NOTIFY_OPCODE_STATS]		= iwm_ntf_statistics,
 	[UMAC_CMD_OPCODE_EEPROM_PROXY]		= iwm_ntf_eeprom_proxy,
 	[UMAC_CMD_OPCODE_GET_CHAN_INFO_LIST]	= iwm_ntf_channel_info_list,
+	[UMAC_CMD_OPCODE_STOP_RESUME_STA_TX]	= iwm_ntf_stop_resume_tx,
 	[REPLY_RX_MPDU_CMD]			= iwm_ntf_rx_packet,
 	[UMAC_CMD_OPCODE_WIFI_IF_WRAPPER]	= iwm_ntf_wifi_if_wrapper,
 };