ath10k: speedup htt rx descriptor processing for tx completion

To optimize CPU usage htt rx descriptors will be reused instead of
refilling it for htt rx copy engine (CE5). To support that all htt rx
indications should be processed at same context. FIFO queue is used
to maintain tx completion status for each msdu. This helps to retain
the order of tx completion.

Signed-off-by: Rajkumar Manoharan <rmanohar@qti.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

1 files changed, 33 insertions, 25 deletions

diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c
index 06975bf49351..ea73a233ecd7 100644
--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -226,7 +226,6 @@ void ath10k_htt_rx_free(struct ath10k_htt *htt)
 	tasklet_kill(&htt->rx_replenish_task);
 	tasklet_kill(&htt->txrx_compl_task);
 
-	skb_queue_purge(&htt->tx_compl_q);
 	skb_queue_purge(&htt->rx_compl_q);
 	skb_queue_purge(&htt->rx_in_ord_compl_q);
 	skb_queue_purge(&htt->tx_fetch_ind_q);
@@ -567,7 +566,6 @@ int ath10k_htt_rx_alloc(struct ath10k_htt *htt)
 	tasklet_init(&htt->rx_replenish_task, ath10k_htt_rx_replenish_task,
 		     (unsigned long)htt);
 
-	skb_queue_head_init(&htt->tx_compl_q);
 	skb_queue_head_init(&htt->rx_compl_q);
 	skb_queue_head_init(&htt->rx_in_ord_compl_q);
 	skb_queue_head_init(&htt->tx_fetch_ind_q);
@@ -1678,7 +1676,7 @@ static void ath10k_htt_rx_frag_handler(struct ath10k_htt *htt,
 	}
 }
 
-static void ath10k_htt_rx_frm_tx_compl(struct ath10k *ar,
+static void ath10k_htt_rx_tx_compl_ind(struct ath10k *ar,
 				       struct sk_buff *skb)
 {
 	struct ath10k_htt *htt = &ar->htt;
@@ -1690,19 +1688,19 @@ static void ath10k_htt_rx_frm_tx_compl(struct ath10k *ar,
 
 	switch (status) {
 	case HTT_DATA_TX_STATUS_NO_ACK:
-		tx_done.no_ack = true;
+		tx_done.status = HTT_TX_COMPL_STATE_NOACK;
 		break;
 	case HTT_DATA_TX_STATUS_OK:
-		tx_done.success = true;
+		tx_done.status = HTT_TX_COMPL_STATE_ACK;
 		break;
 	case HTT_DATA_TX_STATUS_DISCARD:
 	case HTT_DATA_TX_STATUS_POSTPONE:
 	case HTT_DATA_TX_STATUS_DOWNLOAD_FAIL:
-		tx_done.discard = true;
+		tx_done.status = HTT_TX_COMPL_STATE_DISCARD;
 		break;
 	default:
 		ath10k_warn(ar, "unhandled tx completion status %d\n", status);
-		tx_done.discard = true;
+		tx_done.status = HTT_TX_COMPL_STATE_DISCARD;
 		break;
 	}
 
@@ -1712,7 +1710,20 @@ static void ath10k_htt_rx_frm_tx_compl(struct ath10k *ar,
 	for (i = 0; i < resp->data_tx_completion.num_msdus; i++) {
 		msdu_id = resp->data_tx_completion.msdus[i];
 		tx_done.msdu_id = __le16_to_cpu(msdu_id);
-		ath10k_txrx_tx_unref(htt, &tx_done);
+
+		/* kfifo_put: In practice firmware shouldn't fire off per-CE
+		 * interrupt and main interrupt (MSI/-X range case) for the same
+		 * HTC service so it should be safe to use kfifo_put w/o lock.
+		 *
+		 * From kfifo_put() documentation:
+		 *  Note that with only one concurrent reader and one concurrent
+		 *  writer, you don't need extra locking to use these macro.
+		 */
+		if (!kfifo_put(&htt->txdone_fifo, tx_done)) {
+			ath10k_warn(ar, "txdone fifo overrun, msdu_id %d status %d\n",
+				    tx_done.msdu_id, tx_done.status);
+			ath10k_txrx_tx_unref(htt, &tx_done);
+		}
 	}
 }
 
@@ -2339,18 +2350,17 @@ void ath10k_htt_t2h_msg_handler(struct ath10k *ar, struct sk_buff *skb)
 		struct htt_tx_done tx_done = {};
 		int status = __le32_to_cpu(resp->mgmt_tx_completion.status);
 
-		tx_done.msdu_id =
-			__le32_to_cpu(resp->mgmt_tx_completion.desc_id);
+		tx_done.msdu_id = __le32_to_cpu(resp->mgmt_tx_completion.desc_id);
 
 		switch (status) {
 		case HTT_MGMT_TX_STATUS_OK:
-			tx_done.success = true;
+			tx_done.status = HTT_TX_COMPL_STATE_ACK;
 			break;
 		case HTT_MGMT_TX_STATUS_RETRY:
-			tx_done.no_ack = true;
+			tx_done.status = HTT_TX_COMPL_STATE_NOACK;
 			break;
 		case HTT_MGMT_TX_STATUS_DROP:
-			tx_done.discard = true;
+			tx_done.status = HTT_TX_COMPL_STATE_DISCARD;
 			break;
 		}
 
@@ -2364,9 +2374,9 @@ void ath10k_htt_t2h_msg_handler(struct ath10k *ar, struct sk_buff *skb)
 		break;
 	}
 	case HTT_T2H_MSG_TYPE_TX_COMPL_IND:
-		skb_queue_tail(&htt->tx_compl_q, skb);
+		ath10k_htt_rx_tx_compl_ind(htt->ar, skb);
 		tasklet_schedule(&htt->txrx_compl_task);
-		return;
+		break;
 	case HTT_T2H_MSG_TYPE_SEC_IND: {
 		struct ath10k *ar = htt->ar;
 		struct htt_security_indication *ev = &resp->security_indication;
@@ -2475,7 +2485,7 @@ static void ath10k_htt_txrx_compl_task(unsigned long ptr)
 {
 	struct ath10k_htt *htt = (struct ath10k_htt *)ptr;
 	struct ath10k *ar = htt->ar;
-	struct sk_buff_head tx_q;
+	struct htt_tx_done tx_done = {};
 	struct sk_buff_head rx_q;
 	struct sk_buff_head rx_ind_q;
 	struct sk_buff_head tx_ind_q;
@@ -2483,15 +2493,10 @@ static void ath10k_htt_txrx_compl_task(unsigned long ptr)
 	struct sk_buff *skb;
 	unsigned long flags;
 
-	__skb_queue_head_init(&tx_q);
 	__skb_queue_head_init(&rx_q);
 	__skb_queue_head_init(&rx_ind_q);
 	__skb_queue_head_init(&tx_ind_q);
 
-	spin_lock_irqsave(&htt->tx_compl_q.lock, flags);
-	skb_queue_splice_init(&htt->tx_compl_q, &tx_q);
-	spin_unlock_irqrestore(&htt->tx_compl_q.lock, flags);
-
 	spin_lock_irqsave(&htt->rx_compl_q.lock, flags);
 	skb_queue_splice_init(&htt->rx_compl_q, &rx_q);
 	spin_unlock_irqrestore(&htt->rx_compl_q.lock, flags);
@@ -2504,10 +2509,13 @@ static void ath10k_htt_txrx_compl_task(unsigned long ptr)
 	skb_queue_splice_init(&htt->tx_fetch_ind_q, &tx_ind_q);
 	spin_unlock_irqrestore(&htt->tx_fetch_ind_q.lock, flags);
 
-	while ((skb = __skb_dequeue(&tx_q))) {
-		ath10k_htt_rx_frm_tx_compl(htt->ar, skb);
-		dev_kfree_skb_any(skb);
-	}
+	/* kfifo_get: called only within txrx_tasklet so it's neatly serialized.
+	 * From kfifo_get() documentation:
+	 *  Note that with only one concurrent reader and one concurrent writer,
+	 *  you don't need extra locking to use these macro.
+	 */
+	while (kfifo_get(&htt->txdone_fifo, &tx_done))
+		ath10k_txrx_tx_unref(htt, &tx_done);
 
 	while ((skb = __skb_dequeue(&tx_ind_q))) {
 		ath10k_htt_rx_tx_fetch_ind(ar, skb);