[RFC net-next V3 4/5] eth: fbnic: Fetch TX pause storm stats

[Mohsin Bashir <mohsin.bashr@gmail.com>]

With pause storm protection in place, track the occurrence of pause
storm events. Since there is a one-to-one mapping between pause storm
interrupts and events, use the interrupt count to track this metric.

./ethtool -I -a eth0
Pause parameters for eth0:
Autonegotiate:	off
RX:		off
TX:		on
Statistics:
  tx_pause_frames: 759657
  rx_pause_frames: 0
  tx_pause_storm_events: 219

Signed-off-by: Mohsin Bashir <mohsin.bashr@gmail.com>
---
 drivers/net/ethernet/meta/fbnic/fbnic_csr.h      |  1 +
 drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c  |  3 +++
 drivers/net/ethernet/meta/fbnic/fbnic_hw_stats.h |  1 +
 drivers/net/ethernet/meta/fbnic/fbnic_mac.c      | 15 +++++++++++++++
 4 files changed, 20 insertions(+)

diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_csr.h b/drivers/net/ethernet/meta/fbnic/fbnic_csr.h
index e68c56237b61..72eb22a52572 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_csr.h
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_csr.h
@@ -627,6 +627,7 @@ enum {
 	FBNIC_RXB_ENQUEUE_INDICES	= 4
 };
 
+#define FBNIC_RXB_INTR_PS_COUNT(n)	(0x080e9 + (n))	/* 0x203a4 + 4*n */
 #define FBNIC_RXB_DRBO_FRM_CNT_SRC(n)	(0x080f9 + (n))	/* 0x203e4 + 4*n */
 #define FBNIC_RXB_DRBO_BYTE_CNT_SRC_L(n) \
 					(0x080fd + (n))	/* 0x203f4 + 4*n */
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c b/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
index ade9e667640f..70c995b8d1bd 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
@@ -1754,6 +1754,7 @@ fbnic_get_pause_stats(struct net_device *netdev,
 	struct fbnic_net *fbn = netdev_priv(netdev);
 	struct fbnic_mac_stats *mac_stats;
 	struct fbnic_dev *fbd = fbn->fbd;
+	u64 tx_ps_events;
 
 	mac_stats = &fbd->hw_stats.mac;
 
@@ -1761,6 +1762,8 @@ fbnic_get_pause_stats(struct net_device *netdev,
 
 	pause_stats->tx_pause_frames = mac_stats->pause.tx_pause_frames.value;
 	pause_stats->rx_pause_frames = mac_stats->pause.rx_pause_frames.value;
+	tx_ps_events = mac_stats->pause.tx_pause_storm_events.value;
+	pause_stats->tx_pause_storm_events = tx_ps_events;
 }
 
 static void
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_hw_stats.h b/drivers/net/ethernet/meta/fbnic/fbnic_hw_stats.h
index aa3f429a9aed..caea4be46762 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_hw_stats.h
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_hw_stats.h
@@ -54,6 +54,7 @@ struct fbnic_rmon_stats {
 struct fbnic_pause_stats {
 	struct fbnic_stat_counter tx_pause_frames;
 	struct fbnic_stat_counter rx_pause_frames;
+	struct fbnic_stat_counter tx_pause_storm_events;
 };
 
 struct fbnic_eth_mac_stats {
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_mac.c b/drivers/net/ethernet/meta/fbnic/fbnic_mac.c
index 805107ba3b10..53b7a938b4c2 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_mac.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_mac.c
@@ -418,6 +418,18 @@ static void __fbnic_mac_stat_rd64(struct fbnic_dev *fbd, bool reset, u32 reg,
 	stat->reported = true;
 }
 
+static void fbnic_mac_stat_rd32(struct fbnic_dev *fbd, bool reset, u32 reg,
+				struct fbnic_stat_counter *stat)
+{
+	u32 new_reg_value;
+
+	new_reg_value = rd32(fbd, reg);
+	if (!reset)
+		stat->value += new_reg_value - stat->u.old_reg_value_32;
+	stat->u.old_reg_value_32 = new_reg_value;
+	stat->reported = true;
+}
+
 #define fbnic_mac_stat_rd64(fbd, reset, __stat, __CSR) \
 	__fbnic_mac_stat_rd64(fbd, reset, FBNIC_##__CSR##_L, &(__stat))
 
@@ -812,6 +824,9 @@ fbnic_mac_get_pause_stats(struct fbnic_dev *fbd, bool reset,
 			    MAC_STAT_TX_XOFF_STB);
 	fbnic_mac_stat_rd64(fbd, reset, pause_stats->rx_pause_frames,
 			    MAC_STAT_RX_XOFF_STB);
+	fbnic_mac_stat_rd32(fbd, reset,
+			    FBNIC_RXB_INTR_PS_COUNT(FBNIC_RXB_INTF_NET),
+			    &pause_stats->tx_pause_storm_events);
 }
 
 static void
-- 
2.47.3