can: flexcan: add ethtool support to get rx/tx ring parameters

This patch adds ethtool support to get the number of message buffers
configured for reception/transmission, which may also depends on
runtime configurations such as the 'rx-rtr' flag state.

Link: https://lore.kernel.org/all/20220108181633.420433-1-dario.binacchi@amarulasolutions.com
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
[mkl: port to net-next/master, replace __sw_hweight64 by simpler calculation]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/drivers/net/can/flexcan/flexcan-ethtool.c b/drivers/net/can/flexcan/flexcan-ethtool.c
index d01347fbfaa9cf79d7f987d50f85231571d6a99b..3ae53557770071c3ad9a0861bd85447dcb98c845 100644 (file)
--- a/drivers/net/can/flexcan/flexcan-ethtool.c
+++ b/drivers/net/can/flexcan/flexcan-ethtool.c
@@ -17,6 +17,26 @@ static const char flexcan_priv_flags_strings[][ETH_GSTRING_LEN] = {
        "rx-rtr",
 };
 
+static void
+flexcan_get_ringparam(struct net_device *ndev, struct ethtool_ringparam *ring,
+                     struct kernel_ethtool_ringparam *kernel_ring,
+                     struct netlink_ext_ack *ext_ack)
+{
+       const struct flexcan_priv *priv = netdev_priv(ndev);
+
+       ring->rx_max_pending = priv->mb_count;
+       ring->tx_max_pending = priv->mb_count;
+
+       if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_RX_MAILBOX)
+               ring->rx_pending = priv->offload.mb_last -
+                       priv->offload.mb_first + 1;
+       else
+               ring->rx_pending = 6;   /* RX-FIFO depth is fixed */
+
+       /* the drive currently supports only on TX buffer */
+       ring->tx_pending = 1;
+}
+
 static void
 flexcan_get_strings(struct net_device *ndev, u32 stringset, u8 *data)
 {
@@ -81,6 +101,7 @@ static int flexcan_get_sset_count(struct net_device *netdev, int sset)
 }
 
 static const struct ethtool_ops flexcan_ethtool_ops = {
+       .get_ringparam = flexcan_get_ringparam,
        .get_strings = flexcan_get_strings,
        .get_priv_flags = flexcan_get_priv_flags,
        .set_priv_flags = flexcan_set_priv_flags,