net: bcmgenet: log RX buffer allocation and RX/TX dma failures

To help troubleshoot heavy memory pressure conditions, add a bunch of
statistics counter to log RX buffer allocation and RX/TX DMA mapping
failures. These are reported like any other counters through the ethtool
stats interface.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.h b/drivers/net/ethernet/broadcom/genet/bcmgenet.h
index 31b2da5..c4ca728 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.h
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.h
@@ -143,6 +143,9 @@
 	u32	rbuf_ovflow_cnt;
 	u32	rbuf_err_cnt;
 	u32	mdf_err_cnt;
+	u32	alloc_rx_buff_failed;
+	u32	rx_dma_failed;
+	u32	tx_dma_failed;
 };
 
 #define UMAC_HD_BKP_CTRL		0x004