sfc: DMA the VF stats only when requested

Firmware does not support a periodic DMA of vadaptor-stats
on VFs, so only update the stats buffer when stats are
requested (when running "ethtool -S" or an ip/ifconfig
command that reports stats).

Signed-off-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/sfc/mcdi_pcol.h b/drivers/net/ethernet/sfc/mcdi_pcol.h
index 0e497b3..181978d 100644
--- a/drivers/net/ethernet/sfc/mcdi_pcol.h
+++ b/drivers/net/ethernet/sfc/mcdi_pcol.h
@@ -2755,7 +2755,7 @@
 #define MC_CMD_0x2e_PRIVILEGE_CTG SRIOV_CTG_GENERAL
 
 /* MC_CMD_MAC_STATS_IN msgrequest */
-#define    MC_CMD_MAC_STATS_IN_LEN 16
+#define    MC_CMD_MAC_STATS_IN_LEN 20
 /* ??? */
 #define       MC_CMD_MAC_STATS_IN_DMA_ADDR_OFST 0
 #define       MC_CMD_MAC_STATS_IN_DMA_ADDR_LEN 8
@@ -2777,6 +2777,8 @@
 #define        MC_CMD_MAC_STATS_IN_PERIOD_MS_LBN 16
 #define        MC_CMD_MAC_STATS_IN_PERIOD_MS_WIDTH 16
 #define       MC_CMD_MAC_STATS_IN_DMA_LEN_OFST 12
+/* port id so vadapter stats can be provided */
+#define       MC_CMD_MAC_STATS_IN_PORT_ID_OFST 16
 
 /* MC_CMD_MAC_STATS_OUT_DMA msgresponse */
 #define    MC_CMD_MAC_STATS_OUT_DMA_LEN 0