Implement the necessary fpe_map_preemption_class callback for xgmac.

Signed-off-by: Furong Xu <0x1207@gmail.com>
---
 .../ethernet/stmicro/stmmac/dwxgmac2_core.c   |  2 +
 .../net/ethernet/stmicro/stmmac/stmmac_fpe.c  | 43 +++++++++++++++++++
 .../net/ethernet/stmicro/stmmac/stmmac_fpe.h  |  3 ++
 3 files changed, 48 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
index de6ffda31a80..9a60a6e8f633 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
@@ -1545,6 +1545,7 @@ const struct stmmac_ops dwxgmac210_ops = {
 	.config_l3_filter = dwxgmac2_config_l3_filter,
 	.config_l4_filter = dwxgmac2_config_l4_filter,
 	.set_arp_offload = dwxgmac2_set_arp_offload,
+	.fpe_map_preemption_class = dwxgmac3_fpe_map_preemption_class,
 };
 
 static void dwxlgmac2_rx_queue_enable(struct mac_device_info *hw, u8 mode,
@@ -1601,6 +1602,7 @@ const struct stmmac_ops dwxlgmac2_ops = {
 	.config_l3_filter = dwxgmac2_config_l3_filter,
 	.config_l4_filter = dwxgmac2_config_l4_filter,
 	.set_arp_offload = dwxgmac2_set_arp_offload,
+	.fpe_map_preemption_class = dwxgmac3_fpe_map_preemption_class,
 };
 
 int dwxgmac2_setup(struct stmmac_priv *priv)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_fpe.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_fpe.c
index c9c2e0b00a0c..f41329169cc8 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_fpe.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_fpe.c
@@ -350,6 +350,49 @@ int dwmac5_fpe_map_preemption_class(struct net_device *ndev,
 	return 0;
 }
 
+int dwxgmac3_fpe_map_preemption_class(struct net_device *ndev,
+				      struct netlink_ext_ack *extack, u32 pclass)
+{
+	u32 val, offset, count, preemptible_txqs = 0;
+	struct stmmac_priv *priv = netdev_priv(ndev);
+	u32 num_tc = ndev->num_tc;
+
+	if (!num_tc) {
+		/* Restore default TC:Queue mapping */
+		for (u32 i = 0; i < priv->plat->tx_queues_to_use; i++) {
+			val = readl(priv->ioaddr + XGMAC_MTL_TXQ_OPMODE(i));
+			writel(u32_replace_bits(val, i, XGMAC_Q2TCMAP),
+			       priv->ioaddr + XGMAC_MTL_TXQ_OPMODE(i));
+		}
+	}
+
+	/* Synopsys Databook:
+	 * "All Queues within a traffic class are selected in a round robin
+	 * fashion (when packets are available) when the traffic class is
+	 * selected by the scheduler for packet transmission. This is true for
+	 * any of the scheduling algorithms."
+	 */
+	for (u32 tc = 0; tc < num_tc; tc++) {
+		count = ndev->tc_to_txq[tc].count;
+		offset = ndev->tc_to_txq[tc].offset;
+
+		if (pclass & BIT(tc))
+			preemptible_txqs |= GENMASK(offset + count - 1, offset);
+
+		for (u32 i = 0; i < count; i++) {
+			val = readl(priv->ioaddr + XGMAC_MTL_TXQ_OPMODE(offset + i));
+			writel(u32_replace_bits(val, tc, XGMAC_Q2TCMAP),
+			       priv->ioaddr + XGMAC_MTL_TXQ_OPMODE(offset + i));
+		}
+	}
+
+	val = readl(priv->ioaddr + XGMAC_MTL_FPE_CTRL_STS);
+	writel(u32_replace_bits(val, preemptible_txqs, FPE_MTL_PREEMPTION_CLASS),
+	       priv->ioaddr + XGMAC_MTL_FPE_CTRL_STS);
+
+	return 0;
+}
+
 const struct stmmac_fpe_reg dwmac5_fpe_reg = {
 	.mac_fpe_reg = GMAC5_MAC_FPE_CTRL_STS,
 	.mtl_fpe_reg = GMAC5_MTL_FPE_CTRL_STS,
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_fpe.h b/drivers/net/ethernet/stmicro/stmmac/stmmac_fpe.h
index 0b601a9fd805..ea18ea738da6 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_fpe.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_fpe.h
@@ -34,6 +34,9 @@ void stmmac_fpe_set_add_frag_size(struct stmmac_priv *priv, u32 add_frag_size);
 
 int dwmac5_fpe_map_preemption_class(struct net_device *ndev,
 				    struct netlink_ext_ack *extack, u32 pclass);
+int dwxgmac3_fpe_map_preemption_class(struct net_device *ndev,
+				      struct netlink_ext_ack *extack,
+				      u32 pclass);
 
 extern const struct stmmac_fpe_reg dwmac5_fpe_reg;
 extern const struct stmmac_fpe_reg dwxgmac3_fpe_reg;
-- 
2.34.1