[PATCH net-next 2/2] net: dsa: mv88e6xxx: add support for DCB apptrust app
From: Luke Howard
Date: Fri Jul 03 2026 - 02:47:26 EST
Implement port_{get,set}_apptrust for Marvell switches that support it.
This maps to the per-port USE_TAG / USE_IP / TAG_IF_BOTH bits in Port
Control 0, which the driver already initialises for every port (trust
both, IP taking precedence), so apptrust is available across the shared
mv88e6352_dcb_ops families, not only the 6352/6390/6393x.
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Luke Howard <lukeh@xxxxxxxx>
---
drivers/net/dsa/mv88e6xxx/chip.c | 2 +
drivers/net/dsa/mv88e6xxx/chip.h | 6 +++
drivers/net/dsa/mv88e6xxx/dcb.c | 112 +++++++++++++++++++++++++++++++++++++++
drivers/net/dsa/mv88e6xxx/dcb.h | 5 ++
4 files changed, 125 insertions(+)
diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index 3bdf8c7b36612..6b85b2d0a982f 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -7437,6 +7437,8 @@ static const struct dsa_switch_ops mv88e6xxx_switch_ops = {
.port_get_dscp_prio = mv88e6xxx_port_get_dscp_prio,
.port_add_dscp_prio = mv88e6xxx_port_add_dscp_prio,
.port_del_dscp_prio = mv88e6xxx_port_del_dscp_prio,
+ .port_get_apptrust = mv88e6xxx_port_get_apptrust,
+ .port_set_apptrust = mv88e6xxx_port_set_apptrust,
.port_setup_tc = mv88e6xxx_port_setup_tc,
.cls_flower_add = mv88e6xxx_cls_flower_add,
.cls_flower_del = mv88e6xxx_cls_flower_del,
diff --git a/drivers/net/dsa/mv88e6xxx/chip.h b/drivers/net/dsa/mv88e6xxx/chip.h
index d6265e925574f..e95be110dfa7b 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.h
+++ b/drivers/net/dsa/mv88e6xxx/chip.h
@@ -808,6 +808,12 @@ struct mv88e6xxx_dcb_ops {
u8 dscp, u8 prio);
int (*port_del_dscp_prio)(struct mv88e6xxx_chip *chip, int port,
u8 dscp);
+
+ /* Get/set a port's trusted application priority sources */
+ int (*port_get_apptrust)(struct mv88e6xxx_chip *chip, int port,
+ u8 *sel, int *nsel);
+ int (*port_set_apptrust)(struct mv88e6xxx_chip *chip, int port,
+ const u8 *sel, int nsel);
};
struct mv88e6xxx_ptp_ops {
diff --git a/drivers/net/dsa/mv88e6xxx/dcb.c b/drivers/net/dsa/mv88e6xxx/dcb.c
index c26f43b27f09e..08a08acb9bfad 100644
--- a/drivers/net/dsa/mv88e6xxx/dcb.c
+++ b/drivers/net/dsa/mv88e6xxx/dcb.c
@@ -311,12 +311,86 @@ static int mv88e6390_port_del_dscp_prio(struct mv88e6xxx_chip *chip, int port,
dscp));
}
+/* Application trust (apptrust).
+ *
+ * InitialPri (the UseTag/UseIP bits) selects which ingress values a port
+ * trusts for priority assignment; TagIfBoth breaks the tie when a frame
+ * matches both. DCB lists selectors in increasing precedence, so the
+ * last-named selector is the most trusted.
+ */
+
+static int mv88e6xxx_set_apptrust(struct mv88e6xxx_chip *chip, int port,
+ const u8 *sel, int nsel)
+{
+ bool use_tag = false, use_ip = false, tag_wins = false;
+ u16 reg;
+ int i, err;
+
+ for (i = 0; i < nsel; i++) {
+ switch (sel[i]) {
+ case DCB_APP_SEL_PCP:
+ use_tag = true;
+ tag_wins = true;
+ break;
+ case IEEE_8021QAZ_APP_SEL_DSCP:
+ use_ip = true;
+ tag_wins = false;
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+ }
+
+ err = mv88e6xxx_port_read(chip, port, MV88E6XXX_PORT_CTL0, ®);
+ if (err)
+ return err;
+
+ reg &= ~(MV88E6185_PORT_CTL0_USE_TAG | MV88E6185_PORT_CTL0_USE_IP |
+ MV88E6XXX_PORT_CTL0_TAG_IF_BOTH);
+ if (use_tag)
+ reg |= MV88E6185_PORT_CTL0_USE_TAG;
+ if (use_ip)
+ reg |= MV88E6185_PORT_CTL0_USE_IP;
+ if (use_tag && use_ip && tag_wins)
+ reg |= MV88E6XXX_PORT_CTL0_TAG_IF_BOTH;
+
+ return mv88e6xxx_port_write(chip, port, MV88E6XXX_PORT_CTL0, reg);
+}
+
+static int mv88e6xxx_get_apptrust(struct mv88e6xxx_chip *chip, int port,
+ u8 *sel, int *nsel)
+{
+ bool tag_wins;
+ u16 reg;
+ int err, n = 0;
+
+ err = mv88e6xxx_port_read(chip, port, MV88E6XXX_PORT_CTL0, ®);
+ if (err)
+ return err;
+
+ /* Report in increasing precedence: the winner of TagIfBoth comes last */
+ tag_wins = reg & MV88E6XXX_PORT_CTL0_TAG_IF_BOTH;
+
+ if (!tag_wins && (reg & MV88E6185_PORT_CTL0_USE_TAG))
+ sel[n++] = DCB_APP_SEL_PCP;
+ if (reg & MV88E6185_PORT_CTL0_USE_IP)
+ sel[n++] = IEEE_8021QAZ_APP_SEL_DSCP;
+ if (tag_wins && (reg & MV88E6185_PORT_CTL0_USE_TAG))
+ sel[n++] = DCB_APP_SEL_PCP;
+
+ *nsel = n;
+
+ return 0;
+}
+
const struct mv88e6xxx_dcb_ops mv88e6352_dcb_ops = {
.global_get_pcp_prio = mv88e6352_get_pcp_prio,
.global_set_pcp_prio = mv88e6352_set_pcp_prio,
.global_get_dscp_prio = mv88e6352_get_dscp_prio,
.global_set_dscp_prio = mv88e6352_set_dscp_prio,
.global_del_dscp_prio = mv88e6352_del_dscp_prio,
+ .port_get_apptrust = mv88e6xxx_get_apptrust,
+ .port_set_apptrust = mv88e6xxx_set_apptrust,
};
const struct mv88e6xxx_dcb_ops mv88e6390_dcb_ops = {
@@ -325,6 +399,8 @@ const struct mv88e6xxx_dcb_ops mv88e6390_dcb_ops = {
.port_get_dscp_prio = mv88e6390_port_get_dscp_prio,
.port_set_dscp_prio = mv88e6390_port_set_dscp_prio,
.port_del_dscp_prio = mv88e6390_port_del_dscp_prio,
+ .port_get_apptrust = mv88e6xxx_get_apptrust,
+ .port_set_apptrust = mv88e6xxx_set_apptrust,
};
const struct mv88e6xxx_dcb_ops mv88e6393x_dcb_ops = {
@@ -333,6 +409,8 @@ const struct mv88e6xxx_dcb_ops mv88e6393x_dcb_ops = {
.port_get_dscp_prio = mv88e6390_port_get_dscp_prio,
.port_set_dscp_prio = mv88e6390_port_set_dscp_prio,
.port_del_dscp_prio = mv88e6390_port_del_dscp_prio,
+ .port_get_apptrust = mv88e6xxx_get_apptrust,
+ .port_set_apptrust = mv88e6xxx_set_apptrust,
};
static int mv88e6xxx_dcb_get_pcp_prio(struct mv88e6xxx_chip *chip, int port,
@@ -521,3 +599,37 @@ int mv88e6xxx_port_del_dscp_prio(struct dsa_switch *ds, int port, u8 dscp,
mv88e6xxx_reg_unlock(chip);
return err;
}
+
+int mv88e6xxx_port_get_apptrust(struct dsa_switch *ds, int port, u8 *sel,
+ int *nsel)
+{
+ struct mv88e6xxx_chip *chip = ds->priv;
+ const struct mv88e6xxx_dcb_ops *dcb_ops = chip->info->ops->dcb_ops;
+ int err;
+
+ if (!dcb_ops || !dcb_ops->port_get_apptrust)
+ return -EOPNOTSUPP;
+
+ mv88e6xxx_reg_lock(chip);
+ err = dcb_ops->port_get_apptrust(chip, port, sel, nsel);
+ mv88e6xxx_reg_unlock(chip);
+
+ return err;
+}
+
+int mv88e6xxx_port_set_apptrust(struct dsa_switch *ds, int port, const u8 *sel,
+ int nsel)
+{
+ struct mv88e6xxx_chip *chip = ds->priv;
+ const struct mv88e6xxx_dcb_ops *dcb_ops = chip->info->ops->dcb_ops;
+ int err;
+
+ if (!dcb_ops || !dcb_ops->port_set_apptrust)
+ return -EOPNOTSUPP;
+
+ mv88e6xxx_reg_lock(chip);
+ err = dcb_ops->port_set_apptrust(chip, port, sel, nsel);
+ mv88e6xxx_reg_unlock(chip);
+
+ return err;
+}
diff --git a/drivers/net/dsa/mv88e6xxx/dcb.h b/drivers/net/dsa/mv88e6xxx/dcb.h
index e1cf92bbd8729..256d25d650014 100644
--- a/drivers/net/dsa/mv88e6xxx/dcb.h
+++ b/drivers/net/dsa/mv88e6xxx/dcb.h
@@ -24,4 +24,9 @@ int mv88e6xxx_port_add_dscp_prio(struct dsa_switch *ds, int port, u8 dscp,
int mv88e6xxx_port_del_dscp_prio(struct dsa_switch *ds, int port, u8 dscp,
u8 prio);
+int mv88e6xxx_port_get_apptrust(struct dsa_switch *ds, int port, u8 *sel,
+ int *nsel);
+int mv88e6xxx_port_set_apptrust(struct dsa_switch *ds, int port, const u8 *sel,
+ int nsel);
+
#endif /* _MV88E6XXX_DCB_H_ */
--
2.43.0