bnxt_en: Save ring error counters across reset

Currently, the ring counters are stored in the per ring datastructure.
During reset, all the rings are freed together with the associated
datastructures.  As a result, all the ring error counters will be reset
to zero.

Add logic to keep track of the total error counts of all the rings
and save them before reset (including ifdown).  The next patch will
display these total ring error counters under ethtool -S.

Link: https://lore.kernel.org/netdev/CACKFLimD-bKmJ1tGZOLYRjWzEwxkri-Mw7iFme1x2Dr0twdCeg@mail.gmail.com/
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Link: https://lore.kernel.org/r/20230817231911.165035-5-michael.chan@broadcom.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: Michael Chan

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

@@ -10685,8 +10685,10 @@ static void __bnxt_close_nic(struct bnxt *bp, bool irq_re_init,
 	bnxt_free_skbs(bp);
 
 	/* Save ring stats before shutdown */
-	if (bp->bnapi && irq_re_init)
+	if (bp->bnapi && irq_re_init) {
 		bnxt_get_ring_stats(bp, &bp->net_stats_prev);
+		bnxt_get_ring_err_stats(bp, &bp->ring_err_stats_prev);
+	}
 	if (irq_re_init) {
 		bnxt_free_irq(bp);
 		bnxt_del_napi(bp);
@@ -10935,6 +10937,34 @@ bnxt_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
 	clear_bit(BNXT_STATE_READ_STATS, &bp->state);
 }
 
+static void bnxt_get_one_ring_err_stats(struct bnxt *bp,
+					struct bnxt_total_ring_err_stats *stats,
+					struct bnxt_cp_ring_info *cpr)
+{
+	struct bnxt_sw_stats *sw_stats = &cpr->sw_stats;
+	u64 *hw_stats = cpr->stats.sw_stats;
+
+	stats->rx_total_l4_csum_errors += sw_stats->rx.rx_l4_csum_errors;
+	stats->rx_total_resets += sw_stats->rx.rx_resets;
+	stats->rx_total_buf_errors += sw_stats->rx.rx_buf_errors;
+	stats->rx_total_oom_discards += sw_stats->rx.rx_oom_discards;
+	stats->rx_total_netpoll_discards += sw_stats->rx.rx_netpoll_discards;
+	stats->rx_total_ring_discards +=
+		BNXT_GET_RING_STATS64(hw_stats, rx_discard_pkts);
+	stats->tx_total_ring_discards +=
+		BNXT_GET_RING_STATS64(hw_stats, tx_discard_pkts);
+	stats->total_missed_irqs += sw_stats->cmn.missed_irqs;
+}
+
+void bnxt_get_ring_err_stats(struct bnxt *bp,
+			     struct bnxt_total_ring_err_stats *stats)
+{
+	int i;
+
+	for (i = 0; i < bp->cp_nr_rings; i++)
+		bnxt_get_one_ring_err_stats(bp, stats, &bp->bnapi[i]->cp_ring);
+}
+
 static bool bnxt_mc_list_updated(struct bnxt *bp, u32 *rx_mask)
 {
 	struct net_device *dev = bp->dev;

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

@@ -948,6 +948,17 @@ struct bnxt_sw_stats {
 	struct bnxt_cmn_sw_stats cmn;
 };
 
+struct bnxt_total_ring_err_stats {
+	u64			rx_total_l4_csum_errors;
+	u64			rx_total_resets;
+	u64			rx_total_buf_errors;
+	u64			rx_total_oom_discards;
+	u64			rx_total_netpoll_discards;
+	u64			rx_total_ring_discards;
+	u64			tx_total_ring_discards;
+	u64			total_missed_irqs;
+};
+
 struct bnxt_stats_mem {
 	u64		*sw_stats;
 	u64		*hw_masks;
@@ -2018,6 +2029,8 @@ struct bnxt {
 	u8			pri2cos_idx[8];
 	u8			pri2cos_valid;
 
+	struct bnxt_total_ring_err_stats ring_err_stats_prev;
+
 	u16			hwrm_max_req_len;
 	u16			hwrm_max_ext_req_len;
 	unsigned int		hwrm_cmd_timeout;
@@ -2344,6 +2357,8 @@ int bnxt_half_open_nic(struct bnxt *bp);
 void bnxt_half_close_nic(struct bnxt *bp);
 void bnxt_reenable_sriov(struct bnxt *bp);
 int bnxt_close_nic(struct bnxt *, bool, bool);
+void bnxt_get_ring_err_stats(struct bnxt *bp,
+			     struct bnxt_total_ring_err_stats *stats);
 int bnxt_dbg_hwrm_rd_reg(struct bnxt *bp, u32 reg_off, u16 num_words,
 			 u32 *reg_buf);
 void bnxt_fw_exception(struct bnxt *bp);