net: stmmac: add ethtool per-queue irq statistic support

Adding ethtool per-queue statistics support to show number of interrupts
generated at DMA tx and DMA rx. All the counters are incremented at
dwmac4_dma_interrupt function.
Signed-off-by: Vijayakannan Ayyathurai <vijayakannan.ayyathurai@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/common.h

@@ -60,10 +60,12 @@
 
 struct stmmac_txq_stats {
 	unsigned long tx_pkt_n;
+	unsigned long tx_normal_irq_n;
 };
 
 struct stmmac_rxq_stats {
 	unsigned long rx_pkt_n;
+	unsigned long rx_normal_irq_n;
 };
 
 /* Extra statistic and debug information exposed by ethtool */

drivers/net/ethernet/stmicro/stmmac/dwmac4_lib.c

@@ -170,10 +170,12 @@ int dwmac4_dma_interrupt(void __iomem *ioaddr,
 		x->normal_irq_n++;
 	if (likely(intr_status & DMA_CHAN_STATUS_RI)) {
 		x->rx_normal_irq_n++;
+		x->rxq_stats[chan].rx_normal_irq_n++;
 		ret |= handle_rx;
 	}
 	if (likely(intr_status & DMA_CHAN_STATUS_TI)) {
 		x->tx_normal_irq_n++;
+		x->txq_stats[chan].tx_normal_irq_n++;
 		ret |= handle_tx;
 	}
 	if (unlikely(intr_status & DMA_CHAN_STATUS_TBU))

drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c

@@ -263,11 +263,13 @@ static const struct stmmac_stats stmmac_mmc[] = {
 
 static const char stmmac_qstats_tx_string[][ETH_GSTRING_LEN] = {
 	"tx_pkt_n",
+	"tx_irq_n",
 #define STMMAC_TXQ_STATS ARRAY_SIZE(stmmac_qstats_tx_string)
 };
 
 static const char stmmac_qstats_rx_string[][ETH_GSTRING_LEN] = {
 	"rx_pkt_n",
+	"rx_irq_n",
 #define STMMAC_RXQ_STATS ARRAY_SIZE(stmmac_qstats_rx_string)
 };