can: mcp251xfd: ring: add support for runtime configurable RX/TX ring parameters

This patch adds runtime configurable RX and TX ring parameters via
ethtool to the driver.

Link: https://lore.kernel.org/20220313083640.501791-8-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

1 files changed, 35 insertions, 2 deletions

diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-ethtool.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-ethtool.c
index 4131185eaf5a..8825195fa05f 100644
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-ethtool.c
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-ethtool.c
@@ -9,6 +9,7 @@
 #include <linux/ethtool.h>
 
 #include "mcp251xfd.h"
+#include "mcp251xfd-ram.h"
 
 static void
 mcp251xfd_ring_get_ringparam(struct net_device *ndev,
@@ -17,19 +18,51 @@ mcp251xfd_ring_get_ringparam(struct net_device *ndev,
 			     struct netlink_ext_ack *extack)
 {
 	const struct mcp251xfd_priv *priv = netdev_priv(ndev);
+	const bool fd_mode = mcp251xfd_is_fd_mode(priv);
+	struct can_ram_layout layout;
 
-	ring->rx_max_pending = MCP251XFD_RX_OBJ_NUM_MAX;
-	ring->tx_max_pending = MCP251XFD_TX_OBJ_NUM_MAX;
+	can_ram_get_layout(&layout, &mcp251xfd_ram_config, NULL, NULL, fd_mode);
+	ring->rx_max_pending = layout.max_rx;
+	ring->tx_max_pending = layout.max_tx;
 
 	ring->rx_pending = priv->rx_obj_num;
 	ring->tx_pending = priv->tx->obj_num;
 }
 
+static int
+mcp251xfd_ring_set_ringparam(struct net_device *ndev,
+			     struct ethtool_ringparam *ring,
+			     struct kernel_ethtool_ringparam *kernel_ring,
+			     struct netlink_ext_ack *extack)
+{
+	struct mcp251xfd_priv *priv = netdev_priv(ndev);
+	const bool fd_mode = mcp251xfd_is_fd_mode(priv);
+	struct can_ram_layout layout;
+
+	can_ram_get_layout(&layout, &mcp251xfd_ram_config, ring, NULL, fd_mode);
+	if ((layout.cur_rx != priv->rx_obj_num ||
+	     layout.cur_tx != priv->tx->obj_num) &&
+	    netif_running(ndev))
+		return -EBUSY;
+
+	priv->rx_obj_num = layout.cur_rx;
+	priv->tx->obj_num = layout.cur_tx;
+
+	return 0;
+}
+
 static const struct ethtool_ops mcp251xfd_ethtool_ops = {
 	.get_ringparam = mcp251xfd_ring_get_ringparam,
+	.set_ringparam = mcp251xfd_ring_set_ringparam,
 };
 
 void mcp251xfd_ethtool_init(struct mcp251xfd_priv *priv)
 {
+	struct can_ram_layout layout;
+
 	priv->ndev->ethtool_ops = &mcp251xfd_ethtool_ops;
+
+	can_ram_get_layout(&layout, &mcp251xfd_ram_config, NULL, NULL, false);
+	priv->rx_obj_num = layout.default_rx;
+	priv->tx->obj_num = layout.default_tx;
 }