[PATCH net-next v2 7/8] bng_en: periodically fetch and accumulate hardware statistics

[Bhargava Marreddy]

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@xxxxxxxxxxxx>
Reviewed-by: Vikas Gupta <vikas.gupta@xxxxxxxxxxxx>
Reviewed-by: Rahul Gupta <rahul-rg.gupta@xxxxxxxxxxxx>
Reviewed-by: Ajit Kumar Khaparde <ajit.khaparde@xxxxxxxxxxxx>
---
 .../net/ethernet/broadcom/bnge/bnge_netdev.c  | 90 +++++++++++++++++++
 .../net/ethernet/broadcom/bnge/bnge_netdev.h  |  1 +
 2 files changed, 91 insertions(+)

diff --git a/drivers/net/ethernet/broadcom/bnge/bnge_netdev.c b/drivers/net/ethernet/broadcom/bnge/bnge_netdev.c
index c7b5de5a9c2..2b772956df8 100644
--- a/drivers/net/ethernet/broadcom/bnge/bnge_netdev.c
+++ b/drivers/net/ethernet/broadcom/bnge/bnge_netdev.c
@@ -322,9 +322,93 @@ 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)
+{
+	int i;
+
+	for (i = 0; i < count; i++) {
+		u64 hw = le64_to_cpu(READ_ONCE(hw_stats[i]));
+
+		if (masks[i] == -1ULL)
+			sw_stats[i] = hw;
+		else
+			bnge_add_one_ctr(hw, &sw_stats[i], masks[i]);
+	}
+}
+
+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);
+}
+
+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);
+	}
+
+	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;
+		int cnt;
+
+		cnt = sizeof(struct rx_port_stats) / 8;
+		__bnge_accumulate_stats(hw_stats, sw_stats, masks, cnt);
+
+		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);
+	}
+
+	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);
@@ -338,6 +422,12 @@ 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 823060737da..f28edf94257 100644
--- a/drivers/net/ethernet/broadcom/bnge/bnge_netdev.h
+++ b/drivers/net/ethernet/broadcom/bnge/bnge_netdev.h
@@ -305,6 +305,7 @@ 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 {
-- 
2.47.3