ixgbe: Enable jumbo frame for FCoE feature in 82599

Enable jumbo frame when FCoE feature is enabled in 82599. Use 3K
as the receive queue buffer size for receive queues used by FCoE
to address for max Fiber Channel frame size as 2148 bytes (with
max 2112 bytes of payload).

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ixgbe/ixgbe.h

@@ -222,6 +222,10 @@ struct ixgbe_q_vector {
 	(&(((struct ixgbe_adv_tx_context_desc *)((R).desc))[i]))
 
 #define IXGBE_MAX_JUMBO_FRAME_SIZE        16128
+#ifdef IXGBE_FCOE
+/* Use 3K as the baby jumbo frame size for FCoE */
+#define IXGBE_FCOE_JUMBO_FRAME_SIZE       3072
+#endif /* IXGBE_FCOE */
 
 #define OTHER_VECTOR 1
 #define NON_Q_VECTORS (OTHER_VECTOR)

drivers/net/ixgbe/ixgbe_main.c

@@ -1864,6 +1864,10 @@ static void ixgbe_configure_rx(struct ixgbe_adapter *adapter)
 		hlreg0 &= ~IXGBE_HLREG0_JUMBOEN;
 	else
 		hlreg0 |= IXGBE_HLREG0_JUMBOEN;
+#ifdef IXGBE_FCOE
+	if (adapter->flags & IXGBE_FLAG_FCOE_ENABLED)
+		hlreg0 |= IXGBE_HLREG0_JUMBOEN;
+#endif
 	IXGBE_WRITE_REG(hw, IXGBE_HLREG0, hlreg0);
 
 	rdlen = adapter->rx_ring[0].count * sizeof(union ixgbe_adv_rx_desc);
@@ -1885,6 +1889,17 @@ static void ixgbe_configure_rx(struct ixgbe_adapter *adapter)
 		adapter->rx_ring[i].tail = IXGBE_RDT(j);
 		adapter->rx_ring[i].rx_buf_len = rx_buf_len;
 
+#ifdef IXGBE_FCOE
+		if (adapter->flags & IXGBE_FLAG_FCOE_ENABLED) {
+			struct ixgbe_ring_feature *f;
+			f = &adapter->ring_feature[RING_F_FCOE];
+			if ((rx_buf_len < IXGBE_FCOE_JUMBO_FRAME_SIZE) &&
+			    (i >= f->mask) && (i < f->mask + f->indices))
+				adapter->rx_ring[i].rx_buf_len =
+				        IXGBE_FCOE_JUMBO_FRAME_SIZE;
+		}
+
+#endif /* IXGBE_FCOE */
 		ixgbe_configure_srrctl(adapter, j);
 	}
 
@@ -2423,6 +2438,13 @@ static int ixgbe_up_complete(struct ixgbe_adapter *adapter)
 		IXGBE_WRITE_REG(hw, IXGBE_GPIE, gpie);
 	}
 
+#ifdef IXGBE_FCOE
+	/* adjust max frame to be able to do baby jumbo for FCoE */
+	if ((adapter->flags & IXGBE_FLAG_FCOE_ENABLED) &&
+	    (max_frame < IXGBE_FCOE_JUMBO_FRAME_SIZE))
+		max_frame = IXGBE_FCOE_JUMBO_FRAME_SIZE;
+
+#endif /* IXGBE_FCOE */
 	mhadd = IXGBE_READ_REG(hw, IXGBE_MHADD);
 	if (max_frame != (mhadd >> IXGBE_MHADD_MFS_SHIFT)) {
 		mhadd &= ~IXGBE_MHADD_MFS_MASK;