bnxt_en: Add software "missed_irqs" counter.

To keep track of the number of times the workaround code for 57500 A0
has been triggered.  This is a per NQ counter.

Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -8909,6 +8909,7 @@ static void bnxt_chk_missed_irq(struct bnxt *bp)
 			bnxt_dbg_hwrm_ring_info_get(bp,
 				DBG_RING_INFO_GET_REQ_RING_TYPE_L2_CMPL,
 				fw_ring_id, &val[0], &val[1]);
+			cpr->missed_irqs++;
 		}
 	}
 }

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

@@ -818,6 +818,7 @@ struct bnxt_cp_ring_info {
 	dma_addr_t		hw_stats_map;
 	u32			hw_stats_ctx_id;
 	u64			rx_l4_csum_errors;
+	u64			missed_irqs;
 
 	struct bnxt_ring_struct	cp_ring_struct;
 

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

@@ -137,7 +137,7 @@ reset_coalesce:
 	return rc;
 }
 
-#define BNXT_NUM_STATS	21
+#define BNXT_NUM_STATS	22
 
 #define BNXT_RX_STATS_ENTRY(counter)	\
 	{ BNXT_RX_STATS_OFFSET(counter), __stringify(counter) }
@@ -384,6 +384,7 @@ static void bnxt_get_ethtool_stats(struct net_device *dev,
 		for (k = 0; k < stat_fields; j++, k++)
 			buf[j] = le64_to_cpu(hw_stats[k]);
 		buf[j++] = cpr->rx_l4_csum_errors;
+		buf[j++] = cpr->missed_irqs;
 
 		bnxt_sw_func_stats[RX_TOTAL_DISCARDS].counter +=
 			le64_to_cpu(cpr->hw_stats->rx_discard_pkts);
@@ -468,6 +469,8 @@ static void bnxt_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
 			buf += ETH_GSTRING_LEN;
 			sprintf(buf, "[%d]: rx_l4_csum_errors", i);
 			buf += ETH_GSTRING_LEN;
+			sprintf(buf, "[%d]: missed_irqs", i);
+			buf += ETH_GSTRING_LEN;
 		}
 		for (i = 0; i < BNXT_NUM_SW_FUNC_STATS; i++) {
 			strcpy(buf, bnxt_sw_func_stats[i].string);