rtase: Add ndo_setup_tc support for CBS offload in traffic control setup

Add support for ndo_setup_tc to enable CBS offload functionality as
part of traffic control configuration for network devices, where CBS
is applied from the CPU to the switch. More specifically, CBS is
applied at the GMAC in the topmost architecture diagram.

Signed-off-by: Justin Lai <justinlai0215@realtek.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250416115757.28156-1-justinlai0215@realtek.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

1 files changed, 60 insertions, 0 deletions

diff --git a/drivers/net/ethernet/realtek/rtase/rtase_main.c b/drivers/net/ethernet/realtek/rtase/rtase_main.c
index 2aacc1996796..6251548d50ff 100644
--- a/drivers/net/ethernet/realtek/rtase/rtase_main.c
+++ b/drivers/net/ethernet/realtek/rtase/rtase_main.c
@@ -1661,6 +1661,65 @@ static void rtase_get_stats64(struct net_device *dev,
 	stats->rx_length_errors = tp->stats.rx_length_errors;
 }
 
+static void rtase_set_hw_cbs(const struct rtase_private *tp, u32 queue)
+{
+	u32 idle = tp->tx_qos[queue].idleslope * RTASE_1T_CLOCK;
+	u32 val, i;
+
+	val = u32_encode_bits(idle / RTASE_1T_POWER, RTASE_IDLESLOPE_INT_MASK);
+	idle %= RTASE_1T_POWER;
+
+	for (i = 1; i <= RTASE_IDLESLOPE_INT_SHIFT; i++) {
+		idle *= 2;
+		if ((idle / RTASE_1T_POWER) == 1)
+			val |= BIT(RTASE_IDLESLOPE_INT_SHIFT - i);
+
+		idle %= RTASE_1T_POWER;
+	}
+
+	rtase_w32(tp, RTASE_TXQCRDT_0 + queue * 4, val);
+}
+
+static int rtase_setup_tc_cbs(struct rtase_private *tp,
+			      const struct tc_cbs_qopt_offload *qopt)
+{
+	int queue = qopt->queue;
+
+	if (queue < 0 || queue >= tp->func_tx_queue_num)
+		return -EINVAL;
+
+	if (!qopt->enable) {
+		tp->tx_qos[queue].hicredit = 0;
+		tp->tx_qos[queue].locredit = 0;
+		tp->tx_qos[queue].idleslope = 0;
+		tp->tx_qos[queue].sendslope = 0;
+
+		rtase_w32(tp, RTASE_TXQCRDT_0 + queue * 4, 0);
+	} else {
+		tp->tx_qos[queue].hicredit = qopt->hicredit;
+		tp->tx_qos[queue].locredit = qopt->locredit;
+		tp->tx_qos[queue].idleslope = qopt->idleslope;
+		tp->tx_qos[queue].sendslope = qopt->sendslope;
+
+		rtase_set_hw_cbs(tp, queue);
+	}
+
+	return 0;
+}
+
+static int rtase_setup_tc(struct net_device *dev, enum tc_setup_type type,
+			  void *type_data)
+{
+	struct rtase_private *tp = netdev_priv(dev);
+
+	switch (type) {
+	case TC_SETUP_QDISC_CBS:
+		return rtase_setup_tc_cbs(tp, type_data);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
 static netdev_features_t rtase_fix_features(struct net_device *dev,
 					    netdev_features_t features)
 {
@@ -1696,6 +1755,7 @@ static const struct net_device_ops rtase_netdev_ops = {
 	.ndo_change_mtu = rtase_change_mtu,
 	.ndo_tx_timeout = rtase_tx_timeout,
 	.ndo_get_stats64 = rtase_get_stats64,
+	.ndo_setup_tc = rtase_setup_tc,
 	.ndo_fix_features = rtase_fix_features,
 	.ndo_set_features = rtase_set_features,
 };