* [PATCH net-next v5 4/4] net: dsa: yt921x: Add DCB/QoS support
2026-01-28 21:51 [PATCH net-next v5 0/4] net: dsa: yt921x: Add DCB/QoS support David Yang
` (2 preceding siblings ...)
2026-01-28 21:51 ` [PATCH net-next v5 3/4] net: dsa: yt921x: Refactor yt921x_chip_setup() David Yang
@ 2026-01-28 21:51 ` David Yang
3 siblings, 0 replies; 5+ messages in thread
From: David Yang @ 2026-01-28 21:51 UTC (permalink / raw)
To: netdev
Cc: David Yang, Andrew Lunn, Vladimir Oltean, David S. Miller,
Eric Dumazet, Jakub Kicinski, Paolo Abeni, Simon Horman,
Russell King, linux-kernel
Set up global DSCP/PCP priority mappings and add related DCB methods.
Signed-off-by: David Yang <mmyangfl@gmail.com>
---
drivers/net/dsa/Kconfig | 1 +
drivers/net/dsa/yt921x.c | 253 ++++++++++++++++++++++++++++++++++++++-
drivers/net/dsa/yt921x.h | 55 +++++++--
3 files changed, 298 insertions(+), 11 deletions(-)
diff --git a/drivers/net/dsa/Kconfig b/drivers/net/dsa/Kconfig
index 7eb301fd987d..24c37cbf70d7 100644
--- a/drivers/net/dsa/Kconfig
+++ b/drivers/net/dsa/Kconfig
@@ -158,6 +158,7 @@ config NET_DSA_VITESSE_VSC73XX_PLATFORM
config NET_DSA_YT921X
tristate "Motorcomm YT9215 ethernet switch chip support"
select NET_DSA_TAG_YT921X
+ select NET_IEEE8021Q_HELPERS if DCB
help
This enables support for the Motorcomm YT9215 ethernet switch
chip.
diff --git a/drivers/net/dsa/yt921x.c b/drivers/net/dsa/yt921x.c
index 31ed21acb5df..112c2a237d9c 100644
--- a/drivers/net/dsa/yt921x.c
+++ b/drivers/net/dsa/yt921x.c
@@ -8,6 +8,7 @@
* Copyright (c) 2025 David Yang
*/
+#include <linux/dcbnl.h>
#include <linux/etherdevice.h>
#include <linux/if_bridge.h>
#include <linux/if_hsr.h>
@@ -18,8 +19,11 @@
#include <linux/of.h>
#include <linux/of_mdio.h>
#include <linux/of_net.h>
+#include <linux/sort.h>
#include <net/dsa.h>
+#include <net/dscp.h>
+#include <net/ieee8021q.h>
#include "yt921x.h"
@@ -1773,8 +1777,11 @@ yt921x_vlan_aware_set(struct yt921x_priv *priv, int port, bool vlan_aware)
{
u32 ctrl;
+ /* Abuse SVLAN for PCP parsing without polluting the FDB - it just works
+ * despite YT921X_VLAN_CTRL_SVLAN_EN never being set
+ */
if (!vlan_aware)
- ctrl = 0;
+ ctrl = YT921X_PORT_IGR_TPIDn_STAG(0);
else
ctrl = YT921X_PORT_IGR_TPIDn_CTAG(0);
return yt921x_reg_write(priv, YT921X_PORTn_IGR_TPID(port), ctrl);
@@ -2395,6 +2402,122 @@ yt921x_dsa_port_stp_state_set(struct dsa_switch *ds, int port, u8 state)
port, res);
}
+static int __maybe_unused
+yt921x_dsa_port_get_default_prio(struct dsa_switch *ds, int port)
+{
+ struct yt921x_priv *priv = to_yt921x_priv(ds);
+ u32 val;
+ int res;
+
+ mutex_lock(&priv->reg_lock);
+ res = yt921x_reg_read(priv, YT921X_PORTn_QOS(port), &val);
+ mutex_unlock(&priv->reg_lock);
+
+ if (res)
+ return res;
+
+ return FIELD_GET(YT921X_PORT_QOS_PRIO_M, val);
+}
+
+static int __maybe_unused
+yt921x_dsa_port_set_default_prio(struct dsa_switch *ds, int port, u8 prio)
+{
+ struct yt921x_priv *priv = to_yt921x_priv(ds);
+ u32 mask;
+ u32 ctrl;
+ int res;
+
+ if (prio >= YT921X_PRIO_NUM)
+ return -EINVAL;
+
+ mutex_lock(&priv->reg_lock);
+ mask = YT921X_PORT_QOS_PRIO_M | YT921X_PORT_QOS_PRIO_EN;
+ ctrl = YT921X_PORT_QOS_PRIO(prio) | YT921X_PORT_QOS_PRIO_EN;
+ res = yt921x_reg_update_bits(priv, YT921X_PORTn_QOS(port), mask, ctrl);
+ mutex_unlock(&priv->reg_lock);
+
+ return res;
+}
+
+static int __maybe_unused appprios_cmp(const void *a, const void *b)
+{
+ return ((const u8 *)b)[1] - ((const u8 *)a)[1];
+}
+
+static int __maybe_unused
+yt921x_dsa_port_get_apptrust(struct dsa_switch *ds, int port, u8 *sel,
+ int *nselp)
+{
+ struct yt921x_priv *priv = to_yt921x_priv(ds);
+ u8 appprios[2][2] = {};
+ int nsel;
+ u32 val;
+ int res;
+
+ mutex_lock(&priv->reg_lock);
+ res = yt921x_reg_read(priv, YT921X_PORTn_PRIO_ORD(port), &val);
+ mutex_unlock(&priv->reg_lock);
+
+ if (res)
+ return res;
+
+ appprios[0][0] = IEEE_8021QAZ_APP_SEL_DSCP;
+ appprios[0][1] = (val >> (3 * YT921X_APP_SEL_DSCP)) & 7;
+ appprios[1][0] = DCB_APP_SEL_PCP;
+ appprios[1][1] = (val >> (3 * YT921X_APP_SEL_CVLAN_PCP)) & 7;
+ sort(appprios, ARRAY_SIZE(appprios), sizeof(appprios[0]), appprios_cmp,
+ NULL);
+
+ nsel = 0;
+ for (int i = 0; i < ARRAY_SIZE(appprios) && appprios[i][1]; i++) {
+ sel[nsel] = appprios[i][0];
+ nsel++;
+ }
+ *nselp = nsel;
+
+ return 0;
+}
+
+static int __maybe_unused
+yt921x_dsa_port_set_apptrust(struct dsa_switch *ds, int port, const u8 *sel,
+ int nsel)
+{
+ struct yt921x_priv *priv = to_yt921x_priv(ds);
+ struct device *dev = to_device(priv);
+ u32 ctrl;
+ int res;
+
+ if (nsel > YT921X_APP_SEL_NUM)
+ return -EINVAL;
+
+ ctrl = 0;
+ for (int i = 0; i < nsel; i++) {
+ switch (sel[i]) {
+ case IEEE_8021QAZ_APP_SEL_DSCP:
+ ctrl |= YT921X_PORT_PRIO_ORD_APPm(YT921X_APP_SEL_DSCP,
+ 7 - i);
+ break;
+ case DCB_APP_SEL_PCP:
+ ctrl |= YT921X_PORT_PRIO_ORD_APPm(YT921X_APP_SEL_CVLAN_PCP,
+ 7 - i);
+ ctrl |= YT921X_PORT_PRIO_ORD_APPm(YT921X_APP_SEL_SVLAN_PCP,
+ 7 - i);
+ break;
+ default:
+ dev_err(dev,
+ "Invalid apptrust selector (at %d-th). Supported: dscp, pcp\n",
+ i + 1);
+ return -EOPNOTSUPP;
+ }
+ }
+
+ mutex_lock(&priv->reg_lock);
+ res = yt921x_reg_write(priv, YT921X_PORTn_PRIO_ORD(port), ctrl);
+ mutex_unlock(&priv->reg_lock);
+
+ return res;
+}
+
static int yt921x_port_down(struct yt921x_priv *priv, int port)
{
u32 mask;
@@ -2720,6 +2843,13 @@ static int yt921x_port_setup(struct yt921x_priv *priv, int port)
if (res)
return res;
+ /* Clear prio order (even if DCB is not enabled) to avoid unsolicited
+ * priorities
+ */
+ res = yt921x_reg_write(priv, YT921X_PORTn_PRIO_ORD(port), 0);
+ if (res)
+ return res;
+
if (dsa_is_cpu_port(ds, port)) {
/* Egress of CPU port is supposed to be completely controlled
* via tagging, so set to oneway isolated (drop all packets
@@ -2763,6 +2893,66 @@ static int yt921x_dsa_port_setup(struct dsa_switch *ds, int port)
return res;
}
+/* Not "port" - DSCP mapping is global */
+static int __maybe_unused
+yt921x_dsa_port_get_dscp_prio(struct dsa_switch *ds, int port, u8 dscp)
+{
+ struct yt921x_priv *priv = to_yt921x_priv(ds);
+ u32 val;
+ int res;
+
+ mutex_lock(&priv->reg_lock);
+ res = yt921x_reg_read(priv, YT921X_IPM_DSCPn(dscp), &val);
+ mutex_unlock(&priv->reg_lock);
+
+ if (res)
+ return res;
+
+ return FIELD_GET(YT921X_IPM_PRIO_M, val);
+}
+
+static int __maybe_unused
+yt921x_dsa_port_del_dscp_prio(struct dsa_switch *ds, int port, u8 dscp, u8 prio)
+{
+ struct yt921x_priv *priv = to_yt921x_priv(ds);
+ u32 val;
+ int res;
+
+ mutex_lock(&priv->reg_lock);
+ /* During a "dcb app replace" command, the new app table entry will be
+ * added first, then the old one will be deleted. But the hardware only
+ * supports one QoS class per DSCP value (duh), so if we blindly delete
+ * the app table entry for this DSCP value, we end up deleting the
+ * entry with the new priority. Avoid that by checking whether user
+ * space wants to delete the priority which is currently configured, or
+ * something else which is no longer current.
+ */
+ res = yt921x_reg_read(priv, YT921X_IPM_DSCPn(dscp), &val);
+ if (!res && FIELD_GET(YT921X_IPM_PRIO_M, val) == prio)
+ res = yt921x_reg_write(priv, YT921X_IPM_DSCPn(dscp),
+ YT921X_IPM_PRIO(IEEE8021Q_TT_BK));
+ mutex_unlock(&priv->reg_lock);
+
+ return res;
+}
+
+static int __maybe_unused
+yt921x_dsa_port_add_dscp_prio(struct dsa_switch *ds, int port, u8 dscp, u8 prio)
+{
+ struct yt921x_priv *priv = to_yt921x_priv(ds);
+ int res;
+
+ if (prio >= YT921X_PRIO_NUM)
+ return -EINVAL;
+
+ mutex_lock(&priv->reg_lock);
+ res = yt921x_reg_write(priv, YT921X_IPM_DSCPn(dscp),
+ YT921X_IPM_PRIO(prio));
+ mutex_unlock(&priv->reg_lock);
+
+ return res;
+}
+
static int yt921x_edata_wait(struct yt921x_priv *priv, u32 *valp)
{
u32 val = YT921X_EDATA_DATA_IDLE;
@@ -2975,6 +3165,47 @@ static int yt921x_chip_setup_dsa(struct yt921x_priv *priv)
return 0;
}
+static int __maybe_unused yt921x_chip_setup_qos(struct yt921x_priv *priv)
+{
+ u32 ctrl;
+ int res;
+
+ /* DSCP to internal priorities */
+ for (u8 dscp = 0; dscp < DSCP_MAX; dscp++) {
+ int prio = ietf_dscp_to_ieee8021q_tt(dscp);
+
+ if (prio < 0)
+ return prio;
+
+ res = yt921x_reg_write(priv, YT921X_IPM_DSCPn(dscp),
+ YT921X_IPM_PRIO(prio));
+ if (res)
+ return res;
+ }
+
+ /* 802.1Q QoS to internal priorities */
+ for (u8 pcp = 0; pcp < 8; pcp++)
+ for (u8 dei = 0; dei < 2; dei++) {
+ ctrl = YT921X_IPM_PRIO(pcp);
+ if (dei)
+ /* "Red" almost means drop, so it's not that
+ * useful. Note that tc police does not support
+ * Three-Color very well
+ */
+ ctrl |= YT921X_IPM_COLOR_YELLOW;
+
+ for (u8 svlan = 0; svlan < 2; svlan++) {
+ u32 reg = YT921X_IPM_PCPn(svlan, dei, pcp);
+
+ res = yt921x_reg_write(priv, reg, ctrl);
+ if (res)
+ return res;
+ }
+ }
+
+ return 0;
+}
+
static int yt921x_chip_setup(struct yt921x_priv *priv)
{
u32 ctrl;
@@ -2989,6 +3220,12 @@ static int yt921x_chip_setup(struct yt921x_priv *priv)
if (res)
return res;
+#if IS_ENABLED(CONFIG_DCB)
+ res = yt921x_chip_setup_qos(priv);
+ if (res)
+ return res;
+#endif
+
/* Clear MIB */
ctrl = YT921X_MIB_CTRL_CLEAN | YT921X_MIB_CTRL_ALL_PORT;
res = yt921x_reg_write(priv, YT921X_MIB_CTRL, ctrl);
@@ -3104,10 +3341,23 @@ static const struct dsa_switch_ops yt921x_dsa_switch_ops = {
.port_mst_state_set = yt921x_dsa_port_mst_state_set,
.vlan_msti_set = yt921x_dsa_vlan_msti_set,
.port_stp_state_set = yt921x_dsa_port_stp_state_set,
+#if IS_ENABLED(CONFIG_DCB)
+ /* dcb */
+ .port_get_default_prio = yt921x_dsa_port_get_default_prio,
+ .port_set_default_prio = yt921x_dsa_port_set_default_prio,
+ .port_get_apptrust = yt921x_dsa_port_get_apptrust,
+ .port_set_apptrust = yt921x_dsa_port_set_apptrust,
+#endif
/* port */
.get_tag_protocol = yt921x_dsa_get_tag_protocol,
.phylink_get_caps = yt921x_dsa_phylink_get_caps,
.port_setup = yt921x_dsa_port_setup,
+#if IS_ENABLED(CONFIG_DCB)
+ /* dscp */
+ .port_get_dscp_prio = yt921x_dsa_port_get_dscp_prio,
+ .port_del_dscp_prio = yt921x_dsa_port_del_dscp_prio,
+ .port_add_dscp_prio = yt921x_dsa_port_add_dscp_prio,
+#endif
/* chip */
.setup = yt921x_dsa_setup,
};
@@ -3174,6 +3424,7 @@ static int yt921x_mdio_probe(struct mdio_device *mdiodev)
ds = &priv->ds;
ds->dev = dev;
ds->assisted_learning_on_cpu_port = true;
+ ds->dscp_prio_mapping_is_global = true;
ds->priv = priv;
ds->ops = &yt921x_dsa_switch_ops;
ds->ageing_time_min = 1 * 5000;
diff --git a/drivers/net/dsa/yt921x.h b/drivers/net/dsa/yt921x.h
index bacd4ccaa8e5..3f129b8d403f 100644
--- a/drivers/net/dsa/yt921x.h
+++ b/drivers/net/dsa/yt921x.h
@@ -269,6 +269,38 @@
#define YT921X_TPID_EGRn(x) (0x100300 + 4 * (x)) /* [0, 3] */
#define YT921X_TPID_EGR_TPID_M GENMASK(15, 0)
+#define YT921X_IPM_DSCPn(n) (0x180000 + 4 * (n)) /* Internal Priority Map */
+#define YT921X_IPM_PCPn(map, dei, pcp) (0x180100 + 4 * (16 * (map) + 8 * (dei) + (pcp)))
+#define YT921X_IPM_PRIO_M GENMASK(4, 2)
+#define YT921X_IPM_PRIO(x) FIELD_PREP(YT921X_IPM_PRIO_M, (x))
+#define YT921X_IPM_COLOR_M GENMASK(1, 0)
+#define YT921X_IPM_COLOR(x) FIELD_PREP(YT921X_IPM_COLOR_M, (x))
+#define YT921X_IPM_COLOR_GREEN YT921X_IPM_COLOR(0)
+#define YT921X_IPM_COLOR_YELLOW YT921X_IPM_COLOR(1)
+#define YT921X_IPM_COLOR_RED YT921X_IPM_COLOR(2)
+#define YT921X_PORTn_QOS(port) (0x180180 + 4 * (port))
+#define YT921X_PORT_QOS_CVLAN_PRIO_MAP_ID BIT(5)
+#define YT921X_PORT_QOS_SVLAN_PRIO_MAP_ID BIT(4)
+#define YT921X_PORT_QOS_PRIO_M GENMASK(3, 1)
+#define YT921X_PORT_QOS_PRIO(x) FIELD_PREP(YT921X_PORT_QOS_PRIO_M, (x))
+#define YT921X_PORT_QOS_PRIO_EN BIT(0)
+#define YT921X_PORTn_PRIO_ORD(port) (0x180200 + 4 * (port))
+#define YT921X_PORT_PRIO_ORD_APPm_M(m) GENMASK(3 * (m) + 2, 3 * (m))
+#define YT921X_PORT_PRIO_ORD_APPm(m, x) ((x) << (3 * (m))) /* 0: disabled, except PORT_QOS_PRIO */
+
+enum yt921x_app_selector {
+ YT921X_APP_SEL_MAC_SA,
+ YT921X_APP_SEL_MAC_DA,
+ YT921X_APP_SEL_VID,
+ YT921X_APP_SEL_ACL,
+ YT921X_APP_SEL_DSCP,
+ YT921X_APP_SEL_CVLAN_PCP,
+ YT921X_APP_SEL_SVLAN_PCP,
+ /* The physical port, i.e. YT921X_PORT_QOS_PRIO */
+ YT921X_APP_SEL_PORT,
+ YT921X_APP_SEL_NUM
+};
+
#define YT921X_VLAN_IGR_FILTER 0x180280
#define YT921X_VLAN_IGR_FILTER_PORTn_BYPASS_IGMP(port) BIT((port) + 11)
#define YT921X_VLAN_IGR_FILTER_PORTn(port) BIT(port)
@@ -337,7 +369,7 @@
#define YT921X_FDB_OUT0 0x1804b0
#define YT921X_FDB_IO0_ADDR_HI4_M GENMASK(31, 0)
#define YT921X_FDB_OUT1 0x1804b4
-#define YT921X_FDB_IO1_EGR_INT_PRI_EN BIT(31)
+#define YT921X_FDB_IO1_EGR_PRIO_EN BIT(31)
#define YT921X_FDB_IO1_STATUS_M GENMASK(30, 28)
#define YT921X_FDB_IO1_STATUS(x) FIELD_PREP(YT921X_FDB_IO1_STATUS_M, (x))
#define YT921X_FDB_IO1_STATUS_INVALID YT921X_FDB_IO1_STATUS(0)
@@ -356,9 +388,9 @@
#define YT921X_FDB_IO2_EGR_PORTS(x) FIELD_PREP(YT921X_FDB_IO2_EGR_PORTS_M, (x))
#define YT921X_FDB_IO2_EGR_DROP BIT(17)
#define YT921X_FDB_IO2_COPY_TO_CPU BIT(16)
-#define YT921X_FDB_IO2_IGR_INT_PRI_EN BIT(15)
-#define YT921X_FDB_IO2_INT_PRI_M GENMASK(14, 12)
-#define YT921X_FDB_IO2_INT_PRI(x) FIELD_PREP(YT921X_FDB_IO2_INT_PRI_M, (x))
+#define YT921X_FDB_IO2_IGR_PRIO_EN BIT(15)
+#define YT921X_FDB_IO2_PRIO_M GENMASK(14, 12)
+#define YT921X_FDB_IO2_PRIO(x) FIELD_PREP(YT921X_FDB_IO2_PRIO_M, (x))
#define YT921X_FDB_IO2_NEW_VID_M GENMASK(11, 0)
#define YT921X_FDB_IO2_NEW_VID(x) FIELD_PREP(YT921X_FDB_IO2_NEW_VID_M, (x))
#define YT921X_FILTER_UNK_UCAST 0x180508
@@ -406,8 +438,9 @@
#define YT921X_VLAN_CTRL_FID_M GENMASK_ULL(34, 23)
#define YT921X_VLAN_CTRL_FID(x) FIELD_PREP(YT921X_VLAN_CTRL_FID_M, (x))
#define YT921X_VLAN_CTRL_LEARN_DIS BIT_ULL(22)
-#define YT921X_VLAN_CTRL_INT_PRI_EN BIT_ULL(21)
-#define YT921X_VLAN_CTRL_INT_PRI_M GENMASK_ULL(20, 18)
+#define YT921X_VLAN_CTRL_PRIO_EN BIT_ULL(21)
+#define YT921X_VLAN_CTRL_PRIO_M GENMASK_ULL(20, 18)
+#define YT921X_VLAN_CTRL_PRIO(x) FIELD_PREP(YT921X_VLAN_CTRL_PRIO_M, (x))
#define YT921X_VLAN_CTRL_PORTS_M GENMASK_ULL(17, 7)
#define YT921X_VLAN_CTRL_PORTS(x) FIELD_PREP(YT921X_VLAN_CTRL_PORTS_M, (x))
#define YT921X_VLAN_CTRL_PORTn(port) BIT_ULL((port) + 7)
@@ -433,14 +466,14 @@
#define YT921X_LAG_HASH_SRC_PORT BIT(0)
#define YT921X_PORTn_VLAN_CTRL(port) (0x230010 + 4 * (port))
-#define YT921X_PORT_VLAN_CTRL_SVLAN_PRI_EN BIT(31)
-#define YT921X_PORT_VLAN_CTRL_CVLAN_PRI_EN BIT(30)
+#define YT921X_PORT_VLAN_CTRL_SVLAN_PRIO_EN BIT(31)
+#define YT921X_PORT_VLAN_CTRL_CVLAN_PRIO_EN BIT(30)
#define YT921X_PORT_VLAN_CTRL_SVID_M GENMASK(29, 18)
#define YT921X_PORT_VLAN_CTRL_SVID(x) FIELD_PREP(YT921X_PORT_VLAN_CTRL_SVID_M, (x))
#define YT921X_PORT_VLAN_CTRL_CVID_M GENMASK(17, 6)
#define YT921X_PORT_VLAN_CTRL_CVID(x) FIELD_PREP(YT921X_PORT_VLAN_CTRL_CVID_M, (x))
-#define YT921X_PORT_VLAN_CTRL_SVLAN_PRI_M GENMASK(5, 3)
-#define YT921X_PORT_VLAN_CTRL_CVLAN_PRI_M GENMASK(2, 0)
+#define YT921X_PORT_VLAN_CTRL_SVLAN_PRIO_M GENMASK(5, 3)
+#define YT921X_PORT_VLAN_CTRL_CVLAN_PRIO_M GENMASK(2, 0)
#define YT921X_PORTn_VLAN_CTRL1(port) (0x230080 + 4 * (port))
#define YT921X_PORT_VLAN_CTRL1_VLAN_RANGE_EN BIT(8)
#define YT921X_PORT_VLAN_CTRL1_VLAN_RANGE_PROFILE_ID_M GENMASK(7, 4)
@@ -478,6 +511,8 @@ enum yt921x_fdb_entry_status {
#define YT921X_LAG_NUM 2
#define YT921X_LAG_PORT_NUM 4
+#define YT921X_PRIO_NUM 8
+
#define YT9215_MAJOR 0x9002
#define YT9218_MAJOR 0x9001
--
2.51.0
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