ixgbe: Add small packet padding support for X550

This patch sets RDRXCTL.PSP when the driver is in SRIOV mode which
enables padding of small packets.

Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/ixgbe/ixgbe_main.c

@@ -3804,6 +3804,9 @@ static void ixgbe_setup_rdrxctl(struct ixgbe_adapter *adapter)
 		break;
 	case ixgbe_mac_X550:
 	case ixgbe_mac_X550EM_x:
+		if (adapter->num_vfs)
+			rdrxctl |= IXGBE_RDRXCTL_PSP;
+		/* fall through for older HW */
 	case ixgbe_mac_82599EB:
 	case ixgbe_mac_X540:
 		/* Disable RSC for ACK packets */

drivers/net/ethernet/intel/ixgbe/ixgbe_type.h

@@ -1193,6 +1193,7 @@ struct ixgbe_thermal_sensor_data {
 /* RDRXCTL Bit Masks */
 #define IXGBE_RDRXCTL_RDMTS_1_2     0x00000000 /* Rx Desc Min Threshold Size */
 #define IXGBE_RDRXCTL_CRCSTRIP      0x00000002 /* CRC Strip */
+#define IXGBE_RDRXCTL_PSP           0x00000004 /* Pad small packet */
 #define IXGBE_RDRXCTL_MVMEN         0x00000020
 #define IXGBE_RDRXCTL_DMAIDONE      0x00000008 /* DMA init cycle done */
 #define IXGBE_RDRXCTL_AGGDIS        0x00010000 /* Aggregation disable */