ionic: add and enable tx and rx timestamp handling

The Tx and Rx timestamped packets are handled through separate
queues.  Here we set them up, service them, and tear them down
along with the normal Tx and Rx queues.

Signed-off-by: Allen Hubbe <allenbh@pensando.io>
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 106 insertions, 20 deletions

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
index 4859120eec72..3478b0f2495f 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
@@ -11,8 +11,6 @@
 #include "ionic_txrx.h"
 
 
-static bool ionic_tx_service(struct ionic_cq *cq, struct ionic_cq_info *cq_info);
-
 static inline void ionic_txq_post(struct ionic_queue *q, bool ring_dbell,
 				  ionic_desc_cb cb_func, void *cb_arg)
 {
@@ -298,13 +296,33 @@ static void ionic_rx_clean(struct ionic_queue *q,
 		stats->vlan_stripped++;
 	}
 
+	if (unlikely(q->features & IONIC_RXQ_F_HWSTAMP)) {
+		__le64 *cq_desc_hwstamp;
+		u64 hwstamp;
+
+		cq_desc_hwstamp =
+			cq_info->cq_desc +
+			qcq->cq.desc_size -
+			sizeof(struct ionic_rxq_comp) -
+			IONIC_HWSTAMP_CQ_NEGOFFSET;
+
+		hwstamp = le64_to_cpu(*cq_desc_hwstamp);
+
+		if (hwstamp != IONIC_HWSTAMP_INVALID) {
+			skb_hwtstamps(skb)->hwtstamp = ionic_lif_phc_ktime(q->lif, hwstamp);
+			stats->hwstamp_valid++;
+		} else {
+			stats->hwstamp_invalid++;
+		}
+	}
+
 	if (le16_to_cpu(comp->len) <= q->lif->rx_copybreak)
 		napi_gro_receive(&qcq->napi, skb);
 	else
 		napi_gro_frags(&qcq->napi);
 }
 
-static bool ionic_rx_service(struct ionic_cq *cq, struct ionic_cq_info *cq_info)
+bool ionic_rx_service(struct ionic_cq *cq, struct ionic_cq_info *cq_info)
 {
 	struct ionic_queue *q = cq->bound_q;
 	struct ionic_desc_info *desc_info;
@@ -665,9 +683,11 @@ static void ionic_tx_clean(struct ionic_queue *q,
 {
 	struct ionic_buf_info *buf_info = desc_info->bufs;
 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
+	struct ionic_qcq *qcq = q_to_qcq(q);
+	struct sk_buff *skb = cb_arg;
 	struct device *dev = q->dev;
-	u16 queue_index;
 	unsigned int i;
+	u16 qi;
 
 	if (desc_info->nbufs) {
 		dma_unmap_single(dev, (dma_addr_t)buf_info->dma_addr,
@@ -678,24 +698,49 @@ static void ionic_tx_clean(struct ionic_queue *q,
 				       buf_info->len, DMA_TO_DEVICE);
 	}
 
-	if (cb_arg) {
-		struct sk_buff *skb = cb_arg;
+	if (!skb)
+		return;
 
-		queue_index = skb_get_queue_mapping(skb);
-		if (unlikely(__netif_subqueue_stopped(q->lif->netdev,
-						      queue_index))) {
-			netif_wake_subqueue(q->lif->netdev, queue_index);
-			q->wake++;
-		}
+	qi = skb_get_queue_mapping(skb);
+
+	if (unlikely(q->features & IONIC_TXQ_F_HWSTAMP)) {
+		if (cq_info) {
+			struct skb_shared_hwtstamps hwts = {};
+			__le64 *cq_desc_hwstamp;
+			u64 hwstamp;
+
+			cq_desc_hwstamp =
+				cq_info->cq_desc +
+				qcq->cq.desc_size -
+				sizeof(struct ionic_txq_comp) -
+				IONIC_HWSTAMP_CQ_NEGOFFSET;
+
+			hwstamp = le64_to_cpu(*cq_desc_hwstamp);
 
-		desc_info->bytes = skb->len;
-		stats->clean++;
+			if (hwstamp != IONIC_HWSTAMP_INVALID) {
+				hwts.hwtstamp = ionic_lif_phc_ktime(q->lif, hwstamp);
 
-		dev_consume_skb_any(skb);
+				skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
+				skb_tstamp_tx(skb, &hwts);
+
+				stats->hwstamp_valid++;
+			} else {
+				stats->hwstamp_invalid++;
+			}
+		}
+
+	} else if (unlikely(__netif_subqueue_stopped(q->lif->netdev, qi))) {
+		netif_wake_subqueue(q->lif->netdev, qi);
+		q->wake++;
 	}
+
+	desc_info->bytes = skb->len;
+	stats->clean++;
+
+	dev_consume_skb_any(skb);
 }
 
-static bool ionic_tx_service(struct ionic_cq *cq, struct ionic_cq_info *cq_info)
+bool ionic_tx_service(struct ionic_cq *cq, struct ionic_cq_info *cq_info)
 {
 	struct ionic_queue *q = cq->bound_q;
 	struct ionic_desc_info *desc_info;
@@ -726,7 +771,7 @@ static bool ionic_tx_service(struct ionic_cq *cq, struct ionic_cq_info *cq_info)
 		desc_info->cb_arg = NULL;
 	} while (index != le16_to_cpu(comp->comp_index));
 
-	if (pkts && bytes)
+	if (pkts && bytes && !unlikely(q->features & IONIC_TXQ_F_HWSTAMP))
 		netdev_tx_completed_queue(q_to_ndq(q), pkts, bytes);
 
 	return true;
@@ -764,7 +809,7 @@ void ionic_tx_empty(struct ionic_queue *q)
 		desc_info->cb_arg = NULL;
 	}
 
-	if (pkts && bytes)
+	if (pkts && bytes && !unlikely(q->features & IONIC_TXQ_F_HWSTAMP))
 		netdev_tx_completed_queue(q_to_ndq(q), pkts, bytes);
 }
 
@@ -838,7 +883,8 @@ static void ionic_tx_tso_post(struct ionic_queue *q, struct ionic_txq_desc *desc
 
 	if (start) {
 		skb_tx_timestamp(skb);
-		netdev_tx_sent_queue(q_to_ndq(q), skb->len);
+		if (!unlikely(q->features & IONIC_TXQ_F_HWSTAMP))
+			netdev_tx_sent_queue(q_to_ndq(q), skb->len);
 		ionic_txq_post(q, false, ionic_tx_clean, skb);
 	} else {
 		ionic_txq_post(q, done, NULL, NULL);
@@ -1085,7 +1131,8 @@ static int ionic_tx(struct ionic_queue *q, struct sk_buff *skb)
 	stats->pkts++;
 	stats->bytes += skb->len;
 
-	netdev_tx_sent_queue(q_to_ndq(q), skb->len);
+	if (!unlikely(q->features & IONIC_TXQ_F_HWSTAMP))
+		netdev_tx_sent_queue(q_to_ndq(q), skb->len);
 	ionic_txq_post(q, !netdev_xmit_more(), ionic_tx_clean, skb);
 
 	return 0;
@@ -1137,6 +1184,41 @@ static int ionic_maybe_stop_tx(struct ionic_queue *q, int ndescs)
 	return stopped;
 }
 
+static netdev_tx_t ionic_start_hwstamp_xmit(struct sk_buff *skb,
+					    struct net_device *netdev)
+{
+	struct ionic_lif *lif = netdev_priv(netdev);
+	struct ionic_queue *q = &lif->hwstamp_txq->q;
+	int err, ndescs;
+
+	/* Does not stop/start txq, because we post to a separate tx queue
+	 * for timestamping, and if a packet can't be posted immediately to
+	 * the timestamping queue, it is dropped.
+	 */
+
+	ndescs = ionic_tx_descs_needed(q, skb);
+	if (unlikely(ndescs < 0))
+		goto err_out_drop;
+
+	if (unlikely(!ionic_q_has_space(q, ndescs)))
+		goto err_out_drop;
+
+	if (skb_is_gso(skb))
+		err = ionic_tx_tso(q, skb);
+	else
+		err = ionic_tx(q, skb);
+
+	if (err)
+		goto err_out_drop;
+
+	return NETDEV_TX_OK;
+
+err_out_drop:
+	q->drop++;
+	dev_kfree_skb(skb);
+	return NETDEV_TX_OK;
+}
+
 netdev_tx_t ionic_start_xmit(struct sk_buff *skb, struct net_device *netdev)
 {
 	u16 queue_index = skb_get_queue_mapping(skb);
@@ -1150,6 +1232,10 @@ netdev_tx_t ionic_start_xmit(struct sk_buff *skb, struct net_device *netdev)
 		return NETDEV_TX_OK;
 	}
 
+	if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP))
+		if (lif->hwstamp_txq)
+			return ionic_start_hwstamp_xmit(skb, netdev);
+
 	if (unlikely(queue_index >= lif->nxqs))
 		queue_index = 0;
 	q = &lif->txqcqs[queue_index]->q;