Adding upstream version 6.10.3.upstream/6.10.3

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 819 insertions, 0 deletions

diff --git a/drivers/net/dsa/microchip/ksz_dcb.c b/drivers/net/dsa/microchip/ksz_dcb.c
new file mode 100644
index 0000000000..086bc9b3cf
--- /dev/null
+++ b/drivers/net/dsa/microchip/ksz_dcb.c
@@ -0,0 +1,819 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2024 Pengutronix, Oleksij Rempel <kernel@pengutronix.de>
+
+#include <linux/dsa/ksz_common.h>
+#include <net/dsa.h>
+#include <net/dscp.h>
+#include <net/ieee8021q.h>
+
+#include "ksz_common.h"
+#include "ksz_dcb.h"
+#include "ksz8.h"
+
+#define KSZ8_REG_PORT_1_CTRL_0			0x10
+#define KSZ8_PORT_DIFFSERV_ENABLE		BIT(6)
+#define KSZ8_PORT_802_1P_ENABLE			BIT(5)
+#define KSZ8_PORT_BASED_PRIO_M			GENMASK(4, 3)
+
+#define KSZ88X3_REG_TOS_DSCP_CTRL		0x60
+#define KSZ8765_REG_TOS_DSCP_CTRL		0x90
+
+#define KSZ9477_REG_SW_MAC_TOS_CTRL		0x033e
+#define KSZ9477_SW_TOS_DSCP_REMAP		BIT(0)
+#define KSZ9477_SW_TOS_DSCP_DEFAULT_PRIO_M	GENMASK(5, 3)
+
+#define KSZ9477_REG_DIFFSERV_PRIO_MAP		0x0340
+
+#define KSZ9477_REG_PORT_MRI_PRIO_CTRL		0x0801
+#define KSZ9477_PORT_HIGHEST_PRIO		BIT(7)
+#define KSZ9477_PORT_OR_PRIO			BIT(6)
+#define KSZ9477_PORT_MAC_PRIO_ENABLE		BIT(4)
+#define KSZ9477_PORT_VLAN_PRIO_ENABLE		BIT(3)
+#define KSZ9477_PORT_802_1P_PRIO_ENABLE		BIT(2)
+#define KSZ9477_PORT_DIFFSERV_PRIO_ENABLE	BIT(1)
+#define KSZ9477_PORT_ACL_PRIO_ENABLE		BIT(0)
+
+#define KSZ9477_REG_PORT_MRI_MAC_CTRL		0x0802
+#define KSZ9477_PORT_BASED_PRIO_M		GENMASK(2, 0)
+
+struct ksz_apptrust_map {
+	u8 apptrust;
+	u8 bit;
+};
+
+static const struct ksz_apptrust_map ksz8_apptrust_map_to_bit[] = {
+	{ DCB_APP_SEL_PCP, KSZ8_PORT_802_1P_ENABLE },
+	{ IEEE_8021QAZ_APP_SEL_DSCP, KSZ8_PORT_DIFFSERV_ENABLE },
+};
+
+static const struct ksz_apptrust_map ksz9477_apptrust_map_to_bit[] = {
+	{ DCB_APP_SEL_PCP, KSZ9477_PORT_802_1P_PRIO_ENABLE },
+	{ IEEE_8021QAZ_APP_SEL_DSCP, KSZ9477_PORT_DIFFSERV_PRIO_ENABLE },
+};
+
+/* ksz_supported_apptrust[] - Supported apptrust selectors and Priority Order
+ *			      of Internal Priority Map (IPM) sources.
+ *
+ * This array defines the apptrust selectors supported by the hardware, where
+ * the index within the array indicates the priority of the selector - lower
+ * indices correspond to higher priority. This fixed priority scheme is due to
+ * the hardware's design, which does not support configurable priority among
+ * different priority sources.
+ *
+ * The priority sources, including Tail Tag, ACL, VLAN PCP and DSCP are ordered
+ * by the hardware's fixed logic, as detailed below. The order reflects a
+ * non-configurable precedence where certain types of priority information
+ * override others:
+ *
+ * 1. Tail Tag - Highest priority, overrides ACL, VLAN PCP, and DSCP priorities.
+ * 2. ACL - Overrides VLAN PCP and DSCP priorities.
+ * 3. VLAN PCP - Overrides DSCP priority.
+ * 4. DSCP - Lowest priority, does not override any other priority source.
+ *
+ * In this context, the array's lower index (higher priority) for
+ * 'DCB_APP_SEL_PCP' suggests its relative priority over
+ * 'IEEE_8021QAZ_APP_SEL_DSCP' within the system's fixed priority scheme.
+ *
+ * DCB_APP_SEL_PCP - Priority Code Point selector
+ * IEEE_8021QAZ_APP_SEL_DSCP - Differentiated Services Code Point selector
+ */
+static const u8 ksz_supported_apptrust[] = {
+	DCB_APP_SEL_PCP,
+	IEEE_8021QAZ_APP_SEL_DSCP,
+};
+
+static const char * const ksz_supported_apptrust_variants[] = {
+	"empty", "dscp", "pcp", "dscp pcp"
+};
+
+static void ksz_get_default_port_prio_reg(struct ksz_device *dev, int *reg,
+					  u8 *mask, int *shift)
+{
+	if (is_ksz8(dev)) {
+		*reg = KSZ8_REG_PORT_1_CTRL_0;
+		*mask = KSZ8_PORT_BASED_PRIO_M;
+		*shift = __bf_shf(KSZ8_PORT_BASED_PRIO_M);
+	} else {
+		*reg = KSZ9477_REG_PORT_MRI_MAC_CTRL;
+		*mask = KSZ9477_PORT_BASED_PRIO_M;
+		*shift = __bf_shf(KSZ9477_PORT_BASED_PRIO_M);
+	}
+}
+
+/**
+ * ksz_get_dscp_prio_reg - Retrieves the DSCP-to-priority-mapping register
+ * @dev: Pointer to the KSZ switch device structure
+ * @reg: Pointer to the register address to be set
+ * @per_reg: Pointer to the number of DSCP values per register
+ * @mask: Pointer to the mask to be set
+ *
+ * This function retrieves the DSCP to priority mapping register, the number of
+ * DSCP values per register, and the mask to be set.
+ */
+static void ksz_get_dscp_prio_reg(struct ksz_device *dev, int *reg,
+				  int *per_reg, u8 *mask)
+{
+	if (ksz_is_ksz87xx(dev)) {
+		*reg = KSZ8765_REG_TOS_DSCP_CTRL;
+		*per_reg = 4;
+		*mask = GENMASK(1, 0);
+	} else if (ksz_is_ksz88x3(dev)) {
+		*reg = KSZ88X3_REG_TOS_DSCP_CTRL;
+		*per_reg = 4;
+		*mask = GENMASK(1, 0);
+	} else {
+		*reg = KSZ9477_REG_DIFFSERV_PRIO_MAP;
+		*per_reg = 2;
+		*mask = GENMASK(2, 0);
+	}
+}
+
+/**
+ * ksz_get_apptrust_map_and_reg - Retrieves the apptrust map and register
+ * @dev: Pointer to the KSZ switch device structure
+ * @map: Pointer to the apptrust map to be set
+ * @reg: Pointer to the register address to be set
+ * @mask: Pointer to the mask to be set
+ *
+ * This function retrieves the apptrust map and register address for the
+ * apptrust configuration.
+ */
+static void ksz_get_apptrust_map_and_reg(struct ksz_device *dev,
+					 const struct ksz_apptrust_map **map,
+					 int *reg, u8 *mask)
+{
+	if (is_ksz8(dev)) {
+		*map = ksz8_apptrust_map_to_bit;
+		*reg = KSZ8_REG_PORT_1_CTRL_0;
+		*mask = KSZ8_PORT_DIFFSERV_ENABLE | KSZ8_PORT_802_1P_ENABLE;
+	} else {
+		*map = ksz9477_apptrust_map_to_bit;
+		*reg = KSZ9477_REG_PORT_MRI_PRIO_CTRL;
+		*mask = KSZ9477_PORT_802_1P_PRIO_ENABLE |
+			KSZ9477_PORT_DIFFSERV_PRIO_ENABLE;
+	}
+}
+
+/**
+ * ksz_port_get_default_prio - Retrieves the default priority for a port on a
+ *			       KSZ switch
+ * @ds: Pointer to the DSA switch structure
+ * @port: Port number from which to get the default priority
+ *
+ * This function fetches the default priority for the specified port on a KSZ
+ * switch.
+ *
+ * Return: The default priority of the port on success, or a negative error
+ * code on failure.
+ */
+int ksz_port_get_default_prio(struct dsa_switch *ds, int port)
+{
+	struct ksz_device *dev = ds->priv;
+	int ret, reg, shift;
+	u8 data, mask;
+
+	ksz_get_default_port_prio_reg(dev, &reg, &mask, &shift);
+
+	ret = ksz_pread8(dev, port, reg, &data);
+	if (ret)
+		return ret;
+
+	return (data & mask) >> shift;
+}
+
+/**
+ * ksz88x3_port_set_default_prio_quirks - Quirks for default priority
+ * @dev: Pointer to the KSZ switch device structure
+ * @port: Port number for which to set the default priority
+ * @prio: Priority value to set
+ *
+ * This function implements quirks for setting the default priority on KSZ88x3
+ * devices. On Port 2, no other priority providers are working
+ * except of PCP. So, configuring default priority on Port 2 is not possible.
+ * On Port 1, it is not possible to configure port priority if PCP
+ * apptrust on Port 2 is disabled. Since we disable multiple queues on the
+ * switch to disable PCP on Port 2, we need to ensure that the default priority
+ * configuration on Port 1 is in agreement with the configuration on Port 2.
+ *
+ * Return: 0 on success, or a negative error code on failure
+ */
+static int ksz88x3_port_set_default_prio_quirks(struct ksz_device *dev, int port,
+						u8 prio)
+{
+	if (!prio)
+		return 0;
+
+	if (port == KSZ_PORT_2) {
+		dev_err(dev->dev, "Port priority configuration is not working on Port 2\n");
+		return -EINVAL;
+	} else if (port == KSZ_PORT_1) {
+		u8 port2_data;
+		int ret;
+
+		ret = ksz_pread8(dev, KSZ_PORT_2, KSZ8_REG_PORT_1_CTRL_0,
+				 &port2_data);
+		if (ret)
+			return ret;
+
+		if (!(port2_data & KSZ8_PORT_802_1P_ENABLE)) {
+			dev_err(dev->dev, "Not possible to configure port priority on Port 1 if PCP apptrust on Port 2 is disabled\n");
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * ksz_port_set_default_prio - Sets the default priority for a port on a KSZ
+ *			       switch
+ * @ds: Pointer to the DSA switch structure
+ * @port: Port number for which to set the default priority
+ * @prio: Priority value to set
+ *
+ * This function sets the default priority for the specified port on a KSZ
+ * switch.
+ *
+ * Return: 0 on success, or a negative error code on failure.
+ */
+int ksz_port_set_default_prio(struct dsa_switch *ds, int port, u8 prio)
+{
+	struct ksz_device *dev = ds->priv;
+	int reg, shift, ret;
+	u8 mask;
+
+	if (prio >= dev->info->num_ipms)
+		return -EINVAL;
+
+	if (ksz_is_ksz88x3(dev)) {
+		ret = ksz88x3_port_set_default_prio_quirks(dev, port, prio);
+		if (ret)
+			return ret;
+	}
+
+	ksz_get_default_port_prio_reg(dev, &reg, &mask, &shift);
+
+	return ksz_prmw8(dev, port, reg, mask, (prio << shift) & mask);
+}
+
+/**
+ * ksz_port_get_dscp_prio - Retrieves the priority for a DSCP value on a KSZ
+ *			    switch
+ * @ds: Pointer to the DSA switch structure
+ * @port: Port number for which to get the priority
+ * @dscp: DSCP value for which to get the priority
+ *
+ * This function fetches the priority value from switch global DSCP-to-priorty
+ * mapping table for the specified DSCP value.
+ *
+ * Return: The priority value for the DSCP on success, or a negative error
+ * code on failure.
+ */
+int ksz_port_get_dscp_prio(struct dsa_switch *ds, int port, u8 dscp)
+{
+	struct ksz_device *dev = ds->priv;
+	int reg, per_reg, ret, shift;
+	u8 data, mask;
+
+	ksz_get_dscp_prio_reg(dev, &reg, &per_reg, &mask);
+
+	/* If DSCP remapping is disabled, DSCP bits 3-5 are used as Internal
+	 * Priority Map (IPM)
+	 */
+	if (!is_ksz8(dev)) {
+		ret = ksz_read8(dev, KSZ9477_REG_SW_MAC_TOS_CTRL, &data);
+		if (ret)
+			return ret;
+
+		/* If DSCP remapping is disabled, DSCP bits 3-5 are used as
+		 * Internal Priority Map (IPM)
+		 */
+		if (!(data & KSZ9477_SW_TOS_DSCP_REMAP))
+			return FIELD_GET(KSZ9477_SW_TOS_DSCP_DEFAULT_PRIO_M,
+					 dscp);
+	}
+
+	/* In case DSCP remapping is enabled, we need to write the DSCP to
+	 * priority mapping table.
+	 */
+	reg += dscp / per_reg;
+	ret = ksz_read8(dev, reg, &data);
+	if (ret)
+		return ret;
+
+	shift = (dscp % per_reg) * (8 / per_reg);
+
+	return (data >> shift) & mask;
+}
+
+/**
+ * ksz_set_global_dscp_entry - Sets the global DSCP-to-priority mapping entry
+ * @dev: Pointer to the KSZ switch device structure
+ * @dscp: DSCP value for which to set the priority
+ * @ipm: Priority value to set
+ *
+ * This function sets the global DSCP-to-priority mapping entry for the
+ * specified DSCP value.
+ *
+ * Return: 0 on success, or a negative error code on failure.
+ */
+static int ksz_set_global_dscp_entry(struct ksz_device *dev, u8 dscp, u8 ipm)
+{
+	int reg, per_reg, shift;
+	u8 mask;
+
+	ksz_get_dscp_prio_reg(dev, &reg, &per_reg, &mask);
+
+	shift = (dscp % per_reg) * (8 / per_reg);
+
+	return ksz_rmw8(dev, reg + (dscp / per_reg), mask << shift,
+			ipm << shift);
+}
+
+/**
+ * ksz_init_global_dscp_map - Initializes the global DSCP-to-priority mapping
+ * @dev: Pointer to the KSZ switch device structure
+ *
+ * This function initializes the global DSCP-to-priority mapping table for the
+ * switch.
+ *
+ * Return: 0 on success, or a negative error code on failure
+ */
+static int ksz_init_global_dscp_map(struct ksz_device *dev)
+{
+	int ret, dscp;
+
+	/* On KSZ9xxx variants, DSCP remapping is disabled by default.
+	 * Enable to have, predictable and reproducible behavior across
+	 * different devices.
+	 */
+	if (!is_ksz8(dev)) {
+		ret = ksz_rmw8(dev, KSZ9477_REG_SW_MAC_TOS_CTRL,
+			       KSZ9477_SW_TOS_DSCP_REMAP,
+			       KSZ9477_SW_TOS_DSCP_REMAP);
+		if (ret)
+			return ret;
+	}
+
+	for (dscp = 0; dscp < DSCP_MAX; dscp++) {
+		int ipm, tt;
+
+		/* Map DSCP to Traffic Type, which is corresponding to the
+		 * Internal Priority Map (IPM) in the switch.
+		 */
+		if (!is_ksz8(dev)) {
+			ipm = ietf_dscp_to_ieee8021q_tt(dscp);
+		} else {
+			/* On KSZ8xxx variants we do not have IPM to queue
+			 * remapping table. We need to convert DSCP to Traffic
+			 * Type and then to queue.
+			 */
+			tt = ietf_dscp_to_ieee8021q_tt(dscp);
+			if (tt < 0)
+				return tt;
+
+			ipm = ieee8021q_tt_to_tc(tt, dev->info->num_tx_queues);
+		}
+
+		if (ipm < 0)
+			return ipm;
+
+		ret = ksz_set_global_dscp_entry(dev, dscp, ipm);
+	}
+
+	return 0;
+}
+
+/**
+ * ksz_port_add_dscp_prio - Adds a DSCP-to-priority mapping entry for a port on
+ *			    a KSZ switch.
+ * @ds: Pointer to the DSA switch structure
+ * @port: Port number for which to add the DSCP-to-priority mapping entry
+ * @dscp: DSCP value for which to add the priority
+ * @prio: Priority value to set
+ *
+ * Return: 0 on success, or a negative error code on failure
+ */
+int ksz_port_add_dscp_prio(struct dsa_switch *ds, int port, u8 dscp, u8 prio)
+{
+	struct ksz_device *dev = ds->priv;
+
+	if (prio >= dev->info->num_ipms)
+		return -ERANGE;
+
+	return ksz_set_global_dscp_entry(dev, dscp, prio);
+}
+
+/**
+ * ksz_port_del_dscp_prio - Deletes a DSCP-to-priority mapping entry for a port
+ *			    on a KSZ switch.
+ * @ds: Pointer to the DSA switch structure
+ * @port: Port number for which to delete the DSCP-to-priority mapping entry
+ * @dscp: DSCP value for which to delete the priority
+ * @prio: Priority value to delete
+ *
+ * Return: 0 on success, or a negative error code on failure
+ */
+int ksz_port_del_dscp_prio(struct dsa_switch *ds, int port, u8 dscp, u8 prio)
+{
+	struct ksz_device *dev = ds->priv;
+	int ipm;
+
+	if (ksz_port_get_dscp_prio(ds, port, dscp) != prio)
+		return 0;
+
+	if (is_ksz8(dev)) {
+		ipm = ieee8021q_tt_to_tc(IEEE8021Q_TT_BE,
+					 dev->info->num_tx_queues);
+		if (ipm < 0)
+			return ipm;
+	} else {
+		ipm = IEEE8021Q_TT_BE;
+	}
+
+	return ksz_set_global_dscp_entry(dev, dscp, ipm);
+}
+
+/**
+ * ksz_apptrust_error - Prints an error message for an invalid apptrust selector
+ * @dev: Pointer to the KSZ switch device structure
+ *
+ * This function prints an error message when an invalid apptrust selector is
+ * provided.
+ */
+static void ksz_apptrust_error(struct ksz_device *dev)
+{
+	char supported_apptrust_variants[64];
+	int i;
+
+	supported_apptrust_variants[0] = '\0';
+	for (i = 0; i < ARRAY_SIZE(ksz_supported_apptrust_variants); i++) {
+		if (i > 0)
+			strlcat(supported_apptrust_variants, ", ",
+				sizeof(supported_apptrust_variants));
+		strlcat(supported_apptrust_variants,
+			ksz_supported_apptrust_variants[i],
+			sizeof(supported_apptrust_variants));
+	}
+
+	dev_err(dev->dev, "Invalid apptrust selector or priority order. Supported: %s\n",
+		supported_apptrust_variants);
+}
+
+/**
+ * ksz_port_set_apptrust_validate - Validates the apptrust selectors
+ * @dev: Pointer to the KSZ switch device structure
+ * @port: Port number for which to set the apptrust selectors
+ * @sel: Array of apptrust selectors to validate
+ * @nsel: Number of apptrust selectors in the array
+ *
+ * This function validates the apptrust selectors provided and ensures that
+ * they are in the correct order.
+ *
+ * This family of switches supports two apptrust selectors: DCB_APP_SEL_PCP and
+ * IEEE_8021QAZ_APP_SEL_DSCP. The priority order of the selectors is fixed and
+ * cannot be changed. The order is as follows:
+ * 1. DCB_APP_SEL_PCP - Priority Code Point selector (highest priority)
+ * 2. IEEE_8021QAZ_APP_SEL_DSCP - Differentiated Services Code Point selector
+ *   (lowest priority)
+ *
+ * Return: 0 on success, or a negative error code on failure
+ */
+static int ksz_port_set_apptrust_validate(struct ksz_device *dev, int port,
+					  const u8 *sel, int nsel)
+{
+	int i, j, found;
+	int j_prev = 0;
+
+	/* Iterate through the requested selectors */
+	for (i = 0; i < nsel; i++) {
+		found = 0;
+
+		/* Check if the current selector is supported by the hardware */
+		for (j = 0; j < sizeof(ksz_supported_apptrust); j++) {
+			if (sel[i] != ksz_supported_apptrust[j])
+				continue;
+
+			found = 1;
+
+			/* Ensure that no higher priority selector (lower index)
+			 * precedes a lower priority one
+			 */
+			if (i > 0 && j <= j_prev)
+				goto err_sel_not_vaild;
+
+			j_prev = j;
+			break;
+		}
+
+		if (!found)
+			goto err_sel_not_vaild;
+	}
+
+	return 0;
+
+err_sel_not_vaild:
+	ksz_apptrust_error(dev);
+
+	return -EINVAL;
+}
+
+/**
+ * ksz88x3_port1_apptrust_quirk - Quirk for apptrust configuration on Port 1
+ *				  of KSZ88x3 devices
+ * @dev: Pointer to the KSZ switch device structure
+ * @port: Port number for which to set the apptrust selectors
+ * @reg: Register address for the apptrust configuration
+ * @port1_data: Data to set for the apptrust configuration
+ *
+ * This function implements a quirk for apptrust configuration on Port 1 of
+ * KSZ88x3 devices. It ensures that apptrust configuration on Port 1 is not
+ * possible if PCP apptrust on Port 2 is disabled. This is because the Port 2
+ * seems to be permanently hardwired to PCP classification, so we need to
+ * do Port 1 configuration always in agreement with Port 2 configuration.
+ *
+ * Return: 0 on success, or a negative error code on failure
+ */
+static int ksz88x3_port1_apptrust_quirk(struct ksz_device *dev, int port,
+					int reg, u8 port1_data)
+{
+	u8 port2_data;
+	int ret;
+
+	/* If no apptrust is requested for Port 1, no need to care about Port 2
+	 * configuration.
+	 */
+	if (!(port1_data & (KSZ8_PORT_802_1P_ENABLE | KSZ8_PORT_DIFFSERV_ENABLE)))
+		return 0;
+
+	/* We got request to enable any apptrust on Port 1. To make it possible,
+	 * we need to enable multiple queues on the switch. If we enable
+	 * multiqueue support, PCP classification on Port 2 will be
+	 * automatically activated by HW.
+	 */
+	ret = ksz_pread8(dev, KSZ_PORT_2, reg, &port2_data);
+	if (ret)
+		return ret;
+
+	/* If KSZ8_PORT_802_1P_ENABLE bit is set on Port 2, the driver showed
+	 * the interest in PCP classification on Port 2. In this case,
+	 * multiqueue support is enabled and we can enable any apptrust on
+	 * Port 1.
+	 * If KSZ8_PORT_802_1P_ENABLE bit is not set on Port 2, the PCP
+	 * classification on Port 2 is still active, but the driver disabled
+	 * multiqueue support and made frame prioritization inactive for
+	 * all ports. In this case, we can't enable any apptrust on Port 1.
+	 */
+	if (!(port2_data & KSZ8_PORT_802_1P_ENABLE)) {
+		dev_err(dev->dev, "Not possible to enable any apptrust on Port 1 if PCP apptrust on Port 2 is disabled\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * ksz88x3_port2_apptrust_quirk - Quirk for apptrust configuration on Port 2
+ *				  of KSZ88x3 devices
+ * @dev: Pointer to the KSZ switch device structure
+ * @port: Port number for which to set the apptrust selectors
+ * @reg: Register address for the apptrust configuration
+ * @port2_data: Data to set for the apptrust configuration
+ *
+ * This function implements a quirk for apptrust configuration on Port 2 of
+ * KSZ88x3 devices. It ensures that DSCP apptrust is not working on Port 2 and
+ * that it is not possible to disable PCP on Port 2. The only way to disable PCP
+ * on Port 2 is to disable multiple queues on the switch.
+ *
+ * Return: 0 on success, or a negative error code on failure
+ */
+static int ksz88x3_port2_apptrust_quirk(struct ksz_device *dev, int port,
+					int reg, u8 port2_data)
+{
+	struct dsa_switch *ds = dev->ds;
+	u8 port1_data;
+	int ret;
+
+	/* First validate Port 2 configuration. DiffServ/DSCP is not working
+	 * on this port.
+	 */
+	if (port2_data & KSZ8_PORT_DIFFSERV_ENABLE) {
+		dev_err(dev->dev, "DSCP apptrust is not working on Port 2\n");
+		return -EINVAL;
+	}
+
+	/* If PCP support is requested, we need to enable all queues on the
+	 * switch to make PCP priority working on Port 2.
+	 */
+	if (port2_data & KSZ8_PORT_802_1P_ENABLE)
+		return ksz8_all_queues_split(dev, dev->info->num_tx_queues);
+
+	/* We got request to disable PCP priority on Port 2.
+	 * Now, we need to compare Port 2 configuration with Port 1
+	 * configuration.
+	 */
+	ret = ksz_pread8(dev, KSZ_PORT_1, reg, &port1_data);
+	if (ret)
+		return ret;
+
+	/* If Port 1 has any apptrust enabled, we can't disable multiple queues
+	 * on the switch, so we can't disable PCP on Port 2.
+	 */
+	if (port1_data & (KSZ8_PORT_802_1P_ENABLE | KSZ8_PORT_DIFFSERV_ENABLE)) {
+		dev_err(dev->dev, "Not possible to disable PCP on Port 2 if any apptrust is enabled on Port 1\n");
+		return -EINVAL;
+	}
+
+	/* Now we need to ensure that default priority on Port 1 is set to 0
+	 * otherwise we can't disable multiqueue support on the switch.
+	 */
+	ret = ksz_port_get_default_prio(ds, KSZ_PORT_1);
+	if (ret < 0) {
+		return ret;
+	} else if (ret) {
+		dev_err(dev->dev, "Not possible to disable PCP on Port 2 if non zero default priority is set on Port 1\n");
+		return -EINVAL;
+	}
+
+	/* Port 1 has no apptrust or default priority set and we got request to
+	 * disable PCP on Port 2. We can disable multiqueue support to disable
+	 * PCP on Port 2.
+	 */
+	return ksz8_all_queues_split(dev, 1);
+}
+
+/**
+ * ksz88x3_port_apptrust_quirk - Quirk for apptrust configuration on KSZ88x3
+ *			       devices
+ * @dev: Pointer to the KSZ switch device structure
+ * @port: Port number for which to set the apptrust selectors
+ * @reg: Register address for the apptrust configuration
+ * @data: Data to set for the apptrust configuration
+ *
+ * This function implements a quirk for apptrust configuration on KSZ88x3
+ * devices. It ensures that apptrust configuration on Port 1 and
+ * Port 2 is done in agreement with each other.
+ *
+ * Return: 0 on success, or a negative error code on failure
+ */
+static int ksz88x3_port_apptrust_quirk(struct ksz_device *dev, int port,
+				       int reg, u8 data)
+{
+	if (port == KSZ_PORT_1)
+		return ksz88x3_port1_apptrust_quirk(dev, port, reg, data);
+	else if (port == KSZ_PORT_2)
+		return ksz88x3_port2_apptrust_quirk(dev, port, reg, data);
+
+	return 0;
+}
+
+/**
+ * ksz_port_set_apptrust - Sets the apptrust selectors for a port on a KSZ
+ *			   switch
+ * @ds: Pointer to the DSA switch structure
+ * @port: Port number for which to set the apptrust selectors
+ * @sel: Array of apptrust selectors to set
+ * @nsel: Number of apptrust selectors in the array
+ *
+ * This function sets the apptrust selectors for the specified port on a KSZ
+ * switch.
+ *
+ * Return: 0 on success, or a negative error code on failure
+ */
+int ksz_port_set_apptrust(struct dsa_switch *ds, int port,
+			  const u8 *sel, int nsel)
+{
+	const struct ksz_apptrust_map *map;
+	struct ksz_device *dev = ds->priv;
+	int reg, i, ret;
+	u8 data = 0;
+	u8 mask;
+
+	ret = ksz_port_set_apptrust_validate(dev, port, sel, nsel);
+	if (ret)
+		return ret;
+
+	ksz_get_apptrust_map_and_reg(dev, &map, &reg, &mask);
+
+	for (i = 0; i < nsel; i++) {
+		int j;
+
+		for (j = 0; j < ARRAY_SIZE(ksz_supported_apptrust); j++) {
+			if (sel[i] != ksz_supported_apptrust[j])
+				continue;
+
+			data |= map[j].bit;
+			break;
+		}
+	}
+
+	if (ksz_is_ksz88x3(dev)) {
+		ret = ksz88x3_port_apptrust_quirk(dev, port, reg, data);
+		if (ret)
+			return ret;
+	}
+
+	return ksz_prmw8(dev, port, reg, mask, data);
+}
+
+/**
+ * ksz_port_get_apptrust - Retrieves the apptrust selectors for a port on a KSZ
+ *			   switch
+ * @ds: Pointer to the DSA switch structure
+ * @port: Port number for which to get the apptrust selectors
+ * @sel: Array to store the apptrust selectors
+ * @nsel: Number of apptrust selectors in the array
+ *
+ * This function fetches the apptrust selectors for the specified port on a KSZ
+ * switch.
+ *
+ * Return: 0 on success, or a negative error code on failure
+ */
+int ksz_port_get_apptrust(struct dsa_switch *ds, int port, u8 *sel, int *nsel)
+{
+	const struct ksz_apptrust_map *map;
+	struct ksz_device *dev = ds->priv;
+	int reg, i, ret;
+	u8 data;
+	u8 mask;
+
+	ksz_get_apptrust_map_and_reg(dev, &map, &reg, &mask);
+
+	ret = ksz_pread8(dev, port, reg, &data);
+	if (ret)
+		return ret;
+
+	*nsel = 0;
+	for (i = 0; i < ARRAY_SIZE(ksz_supported_apptrust); i++) {
+		if (data & map[i].bit)
+			sel[(*nsel)++] = ksz_supported_apptrust[i];
+	}
+
+	return 0;
+}
+
+/**
+ * ksz_dcb_init_port - Initializes the DCB configuration for a port on a KSZ
+ * @dev: Pointer to the KSZ switch device structure
+ * @port: Port number for which to initialize the DCB configuration
+ *
+ * This function initializes the DCB configuration for the specified port on a
+ * KSZ switch. Particular DCB configuration is set for the port, including the
+ * default priority and apptrust selectors.
+ * The default priority is set to Best Effort, and the apptrust selectors are
+ * set to all supported selectors.
+ *
+ * Return: 0 on success, or a negative error code on failure
+ */
+int ksz_dcb_init_port(struct ksz_device *dev, int port)
+{
+	const u8 ksz_default_apptrust[] = { DCB_APP_SEL_PCP };
+	int ret, ipm;
+
+	if (is_ksz8(dev)) {
+		ipm = ieee8021q_tt_to_tc(IEEE8021Q_TT_BE,
+					 dev->info->num_tx_queues);
+		if (ipm < 0)
+			return ipm;
+	} else {
+		ipm = IEEE8021Q_TT_BE;
+	}
+
+	/* Set the default priority for the port to Best Effort */
+	ret = ksz_port_set_default_prio(dev->ds, port, ipm);
+	if (ret)
+		return ret;
+
+	return ksz_port_set_apptrust(dev->ds, port, ksz_default_apptrust,
+				     ARRAY_SIZE(ksz_default_apptrust));
+}
+
+/**
+ * ksz_dcb_init - Initializes the DCB configuration for a KSZ switch
+ * @dev: Pointer to the KSZ switch device structure
+ *
+ * This function initializes the DCB configuration for a KSZ switch. The global
+ * DSCP-to-priority mapping table is initialized.
+ *
+ * Return: 0 on success, or a negative error code on failure
+ */
+int ksz_dcb_init(struct ksz_device *dev)
+{
+	int ret;
+
+	ret = ksz_init_global_dscp_map(dev);
+	if (ret)
+		return ret;
+
+	/* Enable 802.1p priority control on Port 2 during switch initialization.
+	 * This setup is critical for the apptrust functionality on Port 1, which
+	 * relies on the priority settings of Port 2. Note: Port 1 is naturally
+	 * configured before Port 2, necessitating this configuration order.
+	 */
+	if (ksz_is_ksz88x3(dev))
+		return ksz_prmw8(dev, KSZ_PORT_2, KSZ8_REG_PORT_1_CTRL_0,
+				 KSZ8_PORT_802_1P_ENABLE,
+				 KSZ8_PORT_802_1P_ENABLE);
+
+	return 0;
+}