iwlwifi: setup compressed BA handler

This patch sets the compressed BA handler for 5000. This allows the rate
scaling algorithm to take in count frames that were sent in AMPDUs.

The compressed BA handler has been moved to iwl-rx.c since it is common to
4965 and 5000.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 143 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-tx.c b/drivers/net/wireless/iwlwifi/iwl-tx.c
index 7296e2846ec..032641d4c7d 100644
--- a/drivers/net/wireless/iwlwifi/iwl-tx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-tx.c
@@ -1350,6 +1350,149 @@ int iwl_txq_check_empty(struct iwl_priv *priv, int sta_id, u8 tid, int txq_id)
 }
 EXPORT_SYMBOL(iwl_txq_check_empty);
 
+/**
+ * iwl_tx_status_reply_compressed_ba - Update tx status from block-ack
+ *
+ * Go through block-ack's bitmap of ACK'd frames, update driver's record of
+ * ACK vs. not.  This gets sent to mac80211, then to rate scaling algo.
+ */
+static int iwl_tx_status_reply_compressed_ba(struct iwl_priv *priv,
+				 struct iwl_ht_agg *agg,
+				 struct iwl_compressed_ba_resp *ba_resp)
+
+{
+	int i, sh, ack;
+	u16 seq_ctl = le16_to_cpu(ba_resp->seq_ctl);
+	u16 scd_flow = le16_to_cpu(ba_resp->scd_flow);
+	u64 bitmap;
+	int successes = 0;
+	struct ieee80211_tx_info *info;
+
+	if (unlikely(!agg->wait_for_ba))  {
+		IWL_ERROR("Received BA when not expected\n");
+		return -EINVAL;
+	}
+
+	/* Mark that the expected block-ack response arrived */
+	agg->wait_for_ba = 0;
+	IWL_DEBUG_TX_REPLY("BA %d %d\n", agg->start_idx, ba_resp->seq_ctl);
+
+	/* Calculate shift to align block-ack bits with our Tx window bits */
+	sh = agg->start_idx - SEQ_TO_INDEX(seq_ctl>>4);
+	if (sh < 0) /* tbw something is wrong with indices */
+		sh += 0x100;
+
+	/* don't use 64-bit values for now */
+	bitmap = le64_to_cpu(ba_resp->bitmap) >> sh;
+
+	if (agg->frame_count > (64 - sh)) {
+		IWL_DEBUG_TX_REPLY("more frames than bitmap size");
+		return -1;
+	}
+
+	/* check for success or failure according to the
+	 * transmitted bitmap and block-ack bitmap */
+	bitmap &= agg->bitmap;
+
+	/* For each frame attempted in aggregation,
+	 * update driver's record of tx frame's status. */
+	for (i = 0; i < agg->frame_count ; i++) {
+		ack = bitmap & (1 << i);
+		successes += !!ack;
+		IWL_DEBUG_TX_REPLY("%s ON i=%d idx=%d raw=%d\n",
+			ack? "ACK":"NACK", i, (agg->start_idx + i) & 0xff,
+			agg->start_idx + i);
+	}
+
+	info = IEEE80211_SKB_CB(priv->txq[scd_flow].txb[agg->start_idx].skb[0]);
+	memset(&info->status, 0, sizeof(info->status));
+	info->flags = IEEE80211_TX_STAT_ACK;
+	info->flags |= IEEE80211_TX_STAT_AMPDU;
+	info->status.ampdu_ack_map = successes;
+	info->status.ampdu_ack_len = agg->frame_count;
+	iwl_hwrate_to_tx_control(priv, agg->rate_n_flags, info);
+
+	IWL_DEBUG_TX_REPLY("Bitmap %llx\n", (unsigned long long)bitmap);
+
+	return 0;
+}
+
+/**
+ * iwl_rx_reply_compressed_ba - Handler for REPLY_COMPRESSED_BA
+ *
+ * Handles block-acknowledge notification from device, which reports success
+ * of frames sent via aggregation.
+ */
+void iwl_rx_reply_compressed_ba(struct iwl_priv *priv,
+					   struct iwl_rx_mem_buffer *rxb)
+{
+	struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
+	struct iwl_compressed_ba_resp *ba_resp = &pkt->u.compressed_ba;
+	int index;
+	struct iwl_tx_queue *txq = NULL;
+	struct iwl_ht_agg *agg;
+	DECLARE_MAC_BUF(mac);
+
+	/* "flow" corresponds to Tx queue */
+	u16 scd_flow = le16_to_cpu(ba_resp->scd_flow);
+
+	/* "ssn" is start of block-ack Tx window, corresponds to index
+	 * (in Tx queue's circular buffer) of first TFD/frame in window */
+	u16 ba_resp_scd_ssn = le16_to_cpu(ba_resp->scd_ssn);
+
+	if (scd_flow >= priv->hw_params.max_txq_num) {
+		IWL_ERROR("BUG_ON scd_flow is bigger than number of queues");
+		return;
+	}
+
+	txq = &priv->txq[scd_flow];
+	agg = &priv->stations[ba_resp->sta_id].tid[ba_resp->tid].agg;
+
+	/* Find index just before block-ack window */
+	index = iwl_queue_dec_wrap(ba_resp_scd_ssn & 0xff, txq->q.n_bd);
+
+	/* TODO: Need to get this copy more safely - now good for debug */
+
+	IWL_DEBUG_TX_REPLY("REPLY_COMPRESSED_BA [%d]Received from %s, "
+			   "sta_id = %d\n",
+			   agg->wait_for_ba,
+			   print_mac(mac, (u8 *) &ba_resp->sta_addr_lo32),
+			   ba_resp->sta_id);
+	IWL_DEBUG_TX_REPLY("TID = %d, SeqCtl = %d, bitmap = 0x%llx, scd_flow = "
+			   "%d, scd_ssn = %d\n",
+			   ba_resp->tid,
+			   ba_resp->seq_ctl,
+			   (unsigned long long)le64_to_cpu(ba_resp->bitmap),
+			   ba_resp->scd_flow,
+			   ba_resp->scd_ssn);
+	IWL_DEBUG_TX_REPLY("DAT start_idx = %d, bitmap = 0x%llx \n",
+			   agg->start_idx,
+			   (unsigned long long)agg->bitmap);
+
+	/* Update driver's record of ACK vs. not for each frame in window */
+	iwl_tx_status_reply_compressed_ba(priv, agg, ba_resp);
+
+	/* Release all TFDs before the SSN, i.e. all TFDs in front of
+	 * block-ack window (we assume that they've been successfully
+	 * transmitted ... if not, it's too late anyway). */
+	if (txq->q.read_ptr != (ba_resp_scd_ssn & 0xff)) {
+		/* calculate mac80211 ampdu sw queue to wake */
+		int ampdu_q =
+		   scd_flow - priv->hw_params.first_ampdu_q + priv->hw->queues;
+		int freed = iwl_tx_queue_reclaim(priv, scd_flow, index);
+		priv->stations[ba_resp->sta_id].
+			tid[ba_resp->tid].tfds_in_queue -= freed;
+		if (iwl_queue_space(&txq->q) > txq->q.low_mark &&
+			priv->mac80211_registered &&
+			agg->state != IWL_EMPTYING_HW_QUEUE_DELBA)
+			ieee80211_wake_queue(priv->hw, ampdu_q);
+
+		iwl_txq_check_empty(priv, ba_resp->sta_id,
+				    ba_resp->tid, scd_flow);
+	}
+}
+EXPORT_SYMBOL(iwl_rx_reply_compressed_ba);
+
 #ifdef CONFIG_IWLWIF_DEBUG
 #define TX_STATUS_ENTRY(x) case TX_STATUS_FAIL_ ## x: return #x