bng_en: periodically fetch and accumulate hardware statistics

Use the timer to schedule periodic stats collection via
the workqueue when the link is up. Fetch fresh counters from
hardware via DMA and accumulate them into 64-bit software
shadows, handling wrap-around for counters narrower than
64 bits.

Signed-off-by: Bhargava Marreddy <bhargava.marreddy@broadcom.com>
Reviewed-by: Vikas Gupta <vikas.gupta@broadcom.com>
Reviewed-by: Rahul Gupta <rahul-rg.gupta@broadcom.com>
Reviewed-by: Ajit Kumar Khaparde <ajit.khaparde@broadcom.com>
Link: https://patch.msgid.link/20260406180420.279470-8-bhargava.marreddy@broadcom.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

2 files changed, 99 insertions, 0 deletions

diff --git a/drivers/net/ethernet/broadcom/bnge/bnge_netdev.c b/drivers/net/ethernet/broadcom/bnge/bnge_netdev.c
index 290bf1cd96c9..6f41dff3fbcb 100644
--- a/drivers/net/ethernet/broadcom/bnge/bnge_netdev.c
+++ b/drivers/net/ethernet/broadcom/bnge/bnge_netdev.c
@@ -69,6 +69,9 @@ static int bnge_alloc_stats_mem(struct bnge_net *bn,
 		if (!stats->hw_masks)
 			goto stats_mem_err;
 	}
+
+	u64_stats_init(&stats->syncp);
+
 	return 0;
 
 stats_mem_err:
@@ -294,9 +297,98 @@ static void bnge_timer(struct timer_list *t)
 		}
 	}
 
+	if (BNGE_LINK_IS_UP(bd) && bn->stats_coal_ticks)
+		bnge_queue_sp_work(bn, BNGE_PERIODIC_STATS_SP_EVENT);
+
 	mod_timer(&bn->timer, jiffies + bn->current_interval);
 }
 
+static void bnge_add_one_ctr(u64 hw, u64 *sw, u64 mask)
+{
+	u64 sw_tmp, sw_val;
+
+	hw &= mask;
+	sw_val = READ_ONCE(*sw);
+	sw_tmp = (sw_val & ~mask) | hw;
+	if (hw < (sw_val & mask))
+		sw_tmp += mask + 1;
+	WRITE_ONCE(*sw, sw_tmp);
+}
+
+static void __bnge_accumulate_stats(__le64 *hw_stats, u64 *sw_stats, u64 *masks,
+				    int count, struct u64_stats_sync *syncp)
+{
+	unsigned long flags;
+	int i;
+
+	flags = u64_stats_update_begin_irqsave(syncp);
+	for (i = 0; i < count; i++) {
+		u64 hw = le64_to_cpu(READ_ONCE(hw_stats[i]));
+
+		if (masks[i] == -1ULL)
+			WRITE_ONCE(sw_stats[i], hw);
+		else
+			bnge_add_one_ctr(hw, &sw_stats[i], masks[i]);
+	}
+	u64_stats_update_end_irqrestore(syncp, flags);
+}
+
+static void bnge_accumulate_stats(struct bnge_stats_mem *stats)
+{
+	if (!stats->hw_stats)
+		return;
+
+	__bnge_accumulate_stats(stats->hw_stats, stats->sw_stats,
+				stats->hw_masks, stats->len / 8, &stats->syncp);
+}
+
+static void bnge_accumulate_all_stats(struct bnge_dev *bd)
+{
+	struct bnge_net *bn = netdev_priv(bd->netdev);
+	struct bnge_stats_mem *ring0_stats = NULL;
+	int i;
+
+	for (i = 0; i < bd->nq_nr_rings; i++) {
+		struct bnge_napi *bnapi = bn->bnapi[i];
+		struct bnge_nq_ring_info *nqr;
+		struct bnge_stats_mem *stats;
+
+		nqr = &bnapi->nq_ring;
+		stats = &nqr->stats;
+
+		if (!ring0_stats)
+			ring0_stats = &bn->bnapi[0]->nq_ring.stats;
+
+		__bnge_accumulate_stats(stats->hw_stats, stats->sw_stats,
+					ring0_stats->hw_masks,
+					ring0_stats->len / 8, &stats->syncp);
+	}
+
+	if (bn->flags & BNGE_FLAG_PORT_STATS) {
+		struct bnge_stats_mem *stats = &bn->port_stats;
+		__le64 *hw_stats = stats->hw_stats;
+		u64 *sw_stats = stats->sw_stats;
+		u64 *masks = stats->hw_masks;
+		u16 cnt;
+
+		cnt = sizeof(struct rx_port_stats) / 8;
+		__bnge_accumulate_stats(hw_stats, sw_stats, masks, cnt,
+					&stats->syncp);
+
+		hw_stats += BNGE_TX_PORT_STATS_BYTE_OFFSET / 8;
+		sw_stats += BNGE_TX_PORT_STATS_BYTE_OFFSET / 8;
+		masks += BNGE_TX_PORT_STATS_BYTE_OFFSET / 8;
+		cnt = sizeof(struct tx_port_stats) / 8;
+		__bnge_accumulate_stats(hw_stats, sw_stats, masks, cnt,
+					&stats->syncp);
+	}
+
+	if (bn->flags & BNGE_FLAG_PORT_STATS_EXT) {
+		bnge_accumulate_stats(&bn->rx_port_stats_ext);
+		bnge_accumulate_stats(&bn->tx_port_stats_ext);
+	}
+}
+
 static void bnge_sp_task(struct work_struct *work)
 {
 	struct bnge_net *bn = container_of(work, struct bnge_net, sp_task);
@@ -309,6 +401,12 @@ static void bnge_sp_task(struct work_struct *work)
 		return;
 	}
 
+	if (test_and_clear_bit(BNGE_PERIODIC_STATS_SP_EVENT, &bn->sp_event)) {
+		bnge_hwrm_port_qstats(bd, 0);
+		bnge_hwrm_port_qstats_ext(bd, 0);
+		bnge_accumulate_all_stats(bd);
+	}
+
 	if (test_and_clear_bit(BNGE_UPDATE_PHY_SP_EVENT, &bn->sp_event)) {
 		int rc;
 
diff --git a/drivers/net/ethernet/broadcom/bnge/bnge_netdev.h b/drivers/net/ethernet/broadcom/bnge/bnge_netdev.h
index 15ededb801f6..a73f51b01bc2 100644
--- a/drivers/net/ethernet/broadcom/bnge/bnge_netdev.h
+++ b/drivers/net/ethernet/broadcom/bnge/bnge_netdev.h
@@ -278,6 +278,7 @@ enum bnge_sp_event {
 	BNGE_LINK_SPEED_CHNG_SP_EVENT,
 	BNGE_LINK_CFG_CHANGE_SP_EVENT,
 	BNGE_UPDATE_PHY_SP_EVENT,
+	BNGE_PERIODIC_STATS_SP_EVENT,
 };
 
 struct bnge_net {