From: Yan Markman <ymarkman@marvell.com>
Date: Mon, 11 Dec 2017 09:13:26 +0100
Subject: net: mvpp2: split the max ring size from the default one
Patch-mainline: v4.16-rc1
Git-commit: 7cf87e4a5c2b120967b3fa3a1beb7123eb704d85
References: bsc#1098633

The Rx/Tx ring sizes can be adjusted thanks to ethtool given specific
network needs. This commit splits the default ring size from its max
value to allow ethtool to vary the parameters in both ways.

Signed-off-by: Yan Markman <ymarkman@marvell.com>
[Antoine: commit message]
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/marvell/mvpp2.c |   24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

--- a/drivers/net/ethernet/marvell/mvpp2.c
+++ b/drivers/net/ethernet/marvell/mvpp2.c
@@ -504,10 +504,12 @@
 #define MVPP2_DEFAULT_RXQ		4
 
 /* Max number of Rx descriptors */
-#define MVPP2_MAX_RXD			128
+#define MVPP2_MAX_RXD_MAX		1024
+#define MVPP2_MAX_RXD_DFLT		128
 
 /* Max number of Tx descriptors */
-#define MVPP2_MAX_TXD			1024
+#define MVPP2_MAX_TXD_MAX		2048
+#define MVPP2_MAX_TXD_DFLT		1024
 
 /* Amount of Tx descriptors that can be reserved at once by CPU */
 #define MVPP2_CPU_DESC_CHUNK		64
@@ -6836,13 +6838,13 @@ static int mvpp2_check_ringparam_valid(s
 	if (ring->rx_pending == 0 || ring->tx_pending == 0)
 		return -EINVAL;
 
-	if (ring->rx_pending > MVPP2_MAX_RXD)
-		new_rx_pending = MVPP2_MAX_RXD;
+	if (ring->rx_pending > MVPP2_MAX_RXD_MAX)
+		new_rx_pending = MVPP2_MAX_RXD_MAX;
 	else if (!IS_ALIGNED(ring->rx_pending, 16))
 		new_rx_pending = ALIGN(ring->rx_pending, 16);
 
-	if (ring->tx_pending > MVPP2_MAX_TXD)
-		new_tx_pending = MVPP2_MAX_TXD;
+	if (ring->tx_pending > MVPP2_MAX_TXD_MAX)
+		new_tx_pending = MVPP2_MAX_TXD_MAX;
 	else if (!IS_ALIGNED(ring->tx_pending, 32))
 		new_tx_pending = ALIGN(ring->tx_pending, 32);
 
@@ -7344,8 +7346,8 @@ static void mvpp2_ethtool_get_ringparam(
 {
 	struct mvpp2_port *port = netdev_priv(dev);
 
-	ring->rx_max_pending = MVPP2_MAX_RXD;
-	ring->tx_max_pending = MVPP2_MAX_TXD;
+	ring->rx_max_pending = MVPP2_MAX_RXD_MAX;
+	ring->tx_max_pending = MVPP2_MAX_TXD_MAX;
 	ring->rx_pending = port->rx_ring_size;
 	ring->tx_pending = port->tx_ring_size;
 }
@@ -7792,7 +7794,7 @@ static int mvpp2_port_probe(struct platf
 		goto err_free_netdev;
 	}
 
-	dev->tx_queue_len = MVPP2_MAX_TXD;
+	dev->tx_queue_len = MVPP2_MAX_TXD_MAX;
 	dev->watchdog_timeo = 5 * HZ;
 	dev->netdev_ops = &mvpp2_netdev_ops;
 	dev->ethtool_ops = &mvpp2_eth_tool_ops;
@@ -7875,8 +7877,8 @@ static int mvpp2_port_probe(struct platf
 
 	mvpp2_port_copy_mac_addr(dev, priv, port_node, &mac_from);
 
-	port->tx_ring_size = MVPP2_MAX_TXD;
-	port->rx_ring_size = MVPP2_MAX_RXD;
+	port->tx_ring_size = MVPP2_MAX_TXD_DFLT;
+	port->rx_ring_size = MVPP2_MAX_RXD_DFLT;
 	SET_NETDEV_DEV(dev, &pdev->dev);
 
 	err = mvpp2_port_init(port);