ixgbe: Enable Jumbo Frames on the X540 10Gigabit Controller

The X540 controller supports jumbo frames in SR-IOV mode.  Allow
configuration of jumbo frames either in the PF driver or on behalf of
a VF.
Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ixgbe/ixgbe_main.c

@@ -3077,6 +3077,14 @@ void ixgbe_configure_rx_ring(struct ixgbe_adapter *adapter,
 	ixgbe_configure_srrctl(adapter, ring);
 	ixgbe_configure_rscctl(adapter, ring);
 
+	/* If operating in IOV mode set RLPML for X540 */
+	if ((adapter->flags & IXGBE_FLAG_SRIOV_ENABLED) &&
+	    hw->mac.type == ixgbe_mac_X540) {
+		rxdctl &= ~IXGBE_RXDCTL_RLPMLMASK;
+		rxdctl |= ((ring->netdev->mtu + ETH_HLEN +
+			    ETH_FCS_LEN + VLAN_HLEN) | IXGBE_RXDCTL_RLPML_EN);
+	}
+
 	if (hw->mac.type == ixgbe_mac_82598EB) {
 		/*
 		 * enable cache line friendly hardware writes:
@@ -5441,8 +5449,14 @@ static int ixgbe_change_mtu(struct net_device *netdev, int new_mtu)
 	int max_frame = new_mtu + ETH_HLEN + ETH_FCS_LEN;
 
 	/* MTU < 68 is an error and causes problems on some kernels */
+	if (adapter->flags & IXGBE_FLAG_SRIOV_ENABLED &&
+	    hw->mac.type != ixgbe_mac_X540) {
+		if ((new_mtu < 68) || (max_frame > MAXIMUM_ETHERNET_VLAN_SIZE))
+			return -EINVAL;
+	} else {
 		if ((new_mtu < 68) || (max_frame > IXGBE_MAX_JUMBO_FRAME_SIZE))
 			return -EINVAL;
+	}
 
 	e_info(probe, "changing MTU from %d to %d\n", netdev->mtu, new_mtu);
 	/* must set new MTU before calling down or up */

drivers/net/ixgbe/ixgbe_sriov.c

@@ -110,6 +110,33 @@ static int ixgbe_set_vf_vlan(struct ixgbe_adapter *adapter, int add, int vid,
 	return adapter->hw.mac.ops.set_vfta(&adapter->hw, vid, vf, (bool)add);
 }
 
+void ixgbe_set_vf_lpe(struct ixgbe_adapter *adapter, u32 *msgbuf)
+{
+	struct ixgbe_hw *hw = &adapter->hw;
+	int new_mtu = msgbuf[1];
+	u32 max_frs;
+	int max_frame = new_mtu + ETH_HLEN + ETH_FCS_LEN;
+
+	/* Only X540 supports jumbo frames in IOV mode */
+	if (adapter->hw.mac.type != ixgbe_mac_X540)
+		return;
+
+	/* MTU < 68 is an error and causes problems on some kernels */
+	if ((new_mtu < 68) || (max_frame > IXGBE_MAX_JUMBO_FRAME_SIZE)) {
+		e_err(drv, "VF mtu %d out of range\n", new_mtu);
+		return;
+	}
+
+	max_frs = (IXGBE_READ_REG(hw, IXGBE_MAXFRS) &
+		   IXGBE_MHADD_MFS_MASK) >> IXGBE_MHADD_MFS_SHIFT;
+	if (max_frs < new_mtu) {
+		max_frs = new_mtu << IXGBE_MHADD_MFS_SHIFT;
+		IXGBE_WRITE_REG(hw, IXGBE_MAXFRS, max_frs);
+	}
+
+	e_info(hw, "VF requests change max MTU to %d\n", new_mtu);
+}
+
 static void ixgbe_set_vmolr(struct ixgbe_hw *hw, u32 vf, bool aupe)
 {
 	u32 vmolr = IXGBE_READ_REG(hw, IXGBE_VMOLR(vf));
@@ -302,7 +329,7 @@ static int ixgbe_rcv_msg_from_vf(struct ixgbe_adapter *adapter, u32 vf)
 		                                 hash_list, vf);
 		break;
 	case IXGBE_VF_SET_LPE:
-		WARN_ON((msgbuf[0] & 0xFFFF) == IXGBE_VF_SET_LPE);
+		ixgbe_set_vf_lpe(adapter, msgbuf);
 		break;
 	case IXGBE_VF_SET_VLAN:
 		add = (msgbuf[0] & IXGBE_VT_MSGINFO_MASK)

drivers/net/ixgbe/ixgbe_type.h

@@ -1680,6 +1680,8 @@
 #define IXGBE_RXCTRL_DMBYPS     0x00000002  /* Descriptor Monitor Bypass */
 #define IXGBE_RXDCTL_ENABLE     0x02000000  /* Enable specific Rx Queue */
 #define IXGBE_RXDCTL_VME        0x40000000  /* VLAN mode enable */
+#define IXGBE_RXDCTL_RLPMLMASK  0x00003FFF  /* Only supported on the X540 */
+#define IXGBE_RXDCTL_RLPML_EN   0x00008000
 
 #define IXGBE_FCTRL_SBP 0x00000002 /* Store Bad Packet */
 #define IXGBE_FCTRL_MPE 0x00000100 /* Multicast Promiscuous Ena*/