bnxt_en: add timestamping statistics support

The ethtool_ts_stats structure was introduced earlier this year. Now
it's time to support this group of counters in more drivers.
This patch adds support to bnxt driver.

Signed-off-by: Vadim Fedorenko <vadfed@meta.com>
Reviewed-by: Michael Chan <michael.chan@broadcom.com>
Link: https://lore.kernel.org/r/20240530204751.99636-1-vadfed@meta.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -512,8 +512,11 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)) {
 		struct bnxt_ptp_cfg *ptp = bp->ptp_cfg;
 
-		if (ptp && ptp->tx_tstamp_en && !skb_is_gso(skb) &&
+		if (ptp && ptp->tx_tstamp_en && !skb_is_gso(skb)) {
-		    atomic_dec_if_positive(&ptp->tx_avail) >= 0) {
+			if (!atomic_dec_if_positive(&ptp->tx_avail)) {
+				atomic64_inc(&ptp->stats.ts_err);
+				goto tx_no_ts;
+			}
 			if (!bnxt_ptp_parse(skb, &ptp->tx_seqid,
 					    &ptp->tx_hdr_off)) {
 				if (vlan_tag_flags)
@@ -526,6 +529,7 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev)
 		}
 	}
 
+tx_no_ts:
 	if (unlikely(skb->no_fcs))
 		lflags |= cpu_to_le32(TX_BD_FLAGS_NO_CRC);
 
@@ -732,8 +736,10 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	return NETDEV_TX_OK;
 
 tx_dma_error:
-	if (BNXT_TX_PTP_IS_SET(lflags))
+	if (BNXT_TX_PTP_IS_SET(lflags)) {
+		atomic64_inc(&bp->ptp_cfg->stats.ts_err);
 		atomic_inc(&bp->ptp_cfg->tx_avail);
+	}
 
 	last_frag = i;
 
@@ -812,12 +818,14 @@ static void __bnxt_tx_int(struct bnxt *bp, struct bnxt_tx_ring_info *txr,
 		if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)) {
 			if (BNXT_CHIP_P5(bp)) {
 				/* PTP worker takes ownership of the skb */
-				if (!bnxt_get_tx_ts_p5(bp, skb))
+				if (!bnxt_get_tx_ts_p5(bp, skb)) {
 					skb = NULL;
-				else
+				} else {
+					atomic64_inc(&bp->ptp_cfg->stats.ts_err);
 					atomic_inc(&bp->ptp_cfg->tx_avail);
 				}
 			}
+		}
 
 next_tx_int:
 		cons = NEXT_TX(cons);

drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c

@@ -5233,6 +5233,19 @@ static void bnxt_get_rmon_stats(struct net_device *dev,
 	*ranges = bnxt_rmon_ranges;
 }
 
+static void bnxt_get_ptp_stats(struct net_device *dev,
+			       struct ethtool_ts_stats *ts_stats)
+{
+	struct bnxt *bp = netdev_priv(dev);
+	struct bnxt_ptp_cfg *ptp = bp->ptp_cfg;
+
+	if (ptp) {
+		ts_stats->pkts = ptp->stats.ts_pkts;
+		ts_stats->lost = ptp->stats.ts_lost;
+		ts_stats->err = atomic64_read(&ptp->stats.ts_err);
+	}
+}
+
 static void bnxt_get_link_ext_stats(struct net_device *dev,
 				    struct ethtool_link_ext_stats *stats)
 {
@@ -5316,4 +5329,5 @@ const struct ethtool_ops bnxt_ethtool_ops = {
 	.get_eth_mac_stats	= bnxt_get_eth_mac_stats,
 	.get_eth_ctrl_stats	= bnxt_get_eth_ctrl_stats,
 	.get_rmon_stats		= bnxt_get_rmon_stats,
+	.get_ts_stats		= bnxt_get_ptp_stats,
 };

drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c

@@ -696,11 +696,13 @@ static void bnxt_stamp_tx_skb(struct bnxt *bp, struct sk_buff *skb)
 		spin_unlock_bh(&ptp->ptp_lock);
 		timestamp.hwtstamp = ns_to_ktime(ns);
 		skb_tstamp_tx(ptp->tx_skb, &timestamp);
+		ptp->stats.ts_pkts++;
 	} else {
 		if (!time_after_eq(jiffies, ptp->abs_txts_tmo)) {
 			ptp->txts_pending = true;
 			return;
 		}
+		ptp->stats.ts_lost++;
 		netdev_warn_once(bp->dev,
 				 "TS query for TX timer failed rc = %x\n", rc);
 	}
@@ -979,6 +981,11 @@ int bnxt_ptp_init(struct bnxt *bp, bool phc_cfg)
 		rc = err;
 		goto out;
 	}
+
+	ptp->stats.ts_pkts = 0;
+	ptp->stats.ts_lost = 0;
+	atomic64_set(&ptp->stats.ts_err, 0);
+
 	if (BNXT_CHIP_P5(bp)) {
 		spin_lock_bh(&ptp->ptp_lock);
 		bnxt_refclk_read(bp, NULL, &ptp->current_time);
@@ -1013,5 +1020,6 @@ void bnxt_ptp_clear(struct bnxt *bp)
 		dev_kfree_skb_any(ptp->tx_skb);
 		ptp->tx_skb = NULL;
 	}
+
 	bnxt_unmap_ptp_regs(bp);
 }

drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h

@@ -79,6 +79,12 @@ struct bnxt_pps {
 	struct pps_pin pins[BNXT_MAX_TSIO_PINS];
 };
 
+struct bnxt_ptp_stats {
+	u64		ts_pkts;
+	u64		ts_lost;
+	atomic64_t	ts_err;
+};
+
 struct bnxt_ptp_cfg {
 	struct ptp_clock_info	ptp_info;
 	struct ptp_clock	*ptp_clock;
@@ -125,6 +131,8 @@ struct bnxt_ptp_cfg {
 	u32			refclk_mapped_regs[2];
 	u32			txts_tmo;
 	unsigned long		abs_txts_tmo;
+
+	struct bnxt_ptp_stats	stats;
 };
 
 #if BITS_PER_LONG == 32