be2net: Add a dma_mapping_error counter in ethtool

Add a dma_mapping_error counter to count the number of packets dropped
due to DMA mapping errors.
Signed-off-by: Vasundhara Volam <vasundhara.volam@emulex.com>
Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/emulex/benet/be.h

@@ -323,6 +323,7 @@ struct be_rx_obj {
 struct be_drv_stats {
 	u32 be_on_die_temperature;
 	u32 eth_red_drops;
+	u32 dma_map_errors;
 	u32 rx_drops_no_pbuf;
 	u32 rx_drops_no_txpb;
 	u32 rx_drops_no_erx_descr;

drivers/net/ethernet/emulex/benet/be_ethtool.c

@@ -119,6 +119,8 @@ static const struct be_ethtool_stat et_stats[] = {
 	 * is more than 9018 bytes
 	 */
 	{DRVSTAT_INFO(rx_drops_mtu)},
+	/* Number of dma mapping errors */
+	{DRVSTAT_INFO(dma_map_errors)},
 	/* Number of packets dropped due to random early drop function */
 	{DRVSTAT_INFO(eth_red_drops)},
 	{DRVSTAT_INFO(be_on_die_temperature)},

drivers/net/ethernet/emulex/benet/be_main.c

@@ -849,6 +849,7 @@ static int make_tx_wrbs(struct be_adapter *adapter, struct be_queue_info *txq,
 		unmap_tx_frag(dev, wrb, map_single);
 		map_single = false;
 		copied -= wrb->frag_len;
+		adapter->drv_stats.dma_map_errors++;
 		queue_head_inc(txq);
 	}
 	return 0;
@@ -1877,7 +1878,7 @@ static void be_post_rx_frags(struct be_rx_obj *rxo, gfp_t gfp)
 			if (dma_mapping_error(dev, page_dmaaddr)) {
 				put_page(pagep);
 				pagep = NULL;
-				rx_stats(rxo)->rx_post_fail++;
+				adapter->drv_stats.dma_map_errors++;
 				break;
 			}
 			page_offset = 0;