[PATCH net-next 2/2] net: dsa: motorcomm: Add devlink info and resources

[David Yang <mmyangfl@gmail.com>]

Expose the ASIC model via devlink info (ASIC_ID), and register devlink
resources for ACLs, FDB and meters. Resource occupancy is read back from
the hardware counters for learned FDB entries; static FDB entries are
counted in software.

Signed-off-by: David Yang <mmyangfl@gmail.com>
---
 drivers/net/dsa/motorcomm/Makefile  |   1 +
 drivers/net/dsa/motorcomm/chip.c    |  37 ++++-
 drivers/net/dsa/motorcomm/chip.h    |   3 +
 drivers/net/dsa/motorcomm/devlink.c | 208 ++++++++++++++++++++++++++++
 drivers/net/dsa/motorcomm/devlink.h |  16 +++
 5 files changed, 259 insertions(+), 6 deletions(-)
 create mode 100644 drivers/net/dsa/motorcomm/devlink.c
 create mode 100644 drivers/net/dsa/motorcomm/devlink.h

diff --git a/drivers/net/dsa/motorcomm/Makefile b/drivers/net/dsa/motorcomm/Makefile
index 9eaa59f699e8..0b31d815ce43 100644
--- a/drivers/net/dsa/motorcomm/Makefile
+++ b/drivers/net/dsa/motorcomm/Makefile
@@ -2,6 +2,7 @@
 obj-$(CONFIG_NET_DSA_YT921X) += yt921x.o
 yt921x-objs := chip.o
 yt921x-$(CONFIG_NET_DSA_YT921X_LEDS) += leds.o
+yt921x-objs += devlink.o
 yt921x-objs += mdio_bus.o
 yt921x-objs += mib.o
 yt921x-objs += pcs-921x.o
diff --git a/drivers/net/dsa/motorcomm/chip.c b/drivers/net/dsa/motorcomm/chip.c
index a7a9a7439304..c3c555cb8941 100644
--- a/drivers/net/dsa/motorcomm/chip.c
+++ b/drivers/net/dsa/motorcomm/chip.c
@@ -26,6 +26,7 @@
 #include <net/ieee8021q.h>
 
 #include "chip.h"
+#include "devlink.h"
 #include "leds.h"
 #include "mdio_bus.h"
 #include "mib.h"
@@ -731,6 +732,7 @@ yt921x_fdb_add(struct yt921x_priv *priv, const unsigned char *addr, u16 vid,
 	if (val & YT921X_FDB_RESULT_NOTFOUND)
 		return -ENOSPC;
 
+	priv->fdb_static_cnt++;
 	return 0;
 }
 
@@ -761,18 +763,27 @@ yt921x_fdb_leave(struct yt921x_priv *priv, const unsigned char *addr,
 	ctrl2 = val2 & ~YT921X_FDB_IO2_EGR_PORTS(ports_mask);
 	if (ctrl2 == val2)
 		return 0;
+
+	res = yt921x_reg_read(priv, YT921X_FDB_OUT1, &ctrl1);
+	if (res)
+		return res;
+
 	if (!(ctrl2 & YT921X_FDB_IO2_EGR_PORTS_M)) {
 		ctrl = YT921X_FDB_OP_OP_DEL | YT921X_FDB_OP_START;
 		res = yt921x_reg_write(priv, YT921X_FDB_OP, ctrl);
 		if (res)
 			return res;
 
-		return yt921x_fdb_wait(priv, &val);
-	}
+		res = yt921x_fdb_wait(priv, &val);
+		if (res)
+			return res;
 
-	res = yt921x_reg_read(priv, YT921X_FDB_OUT1, &ctrl1);
-	if (res)
-		return res;
+		if ((ctrl1 & YT921X_FDB_IO1_STATUS_M) ==
+		    YT921X_FDB_IO1_STATUS_STATIC &&
+		    !WARN_ON(!priv->fdb_static_cnt))
+			priv->fdb_static_cnt--;
+		return 0;
+	}
 
 	return yt921x_fdb_add_index_in12(priv, index, ctrl1, ctrl2);
 }
@@ -809,7 +820,14 @@ yt921x_fdb_join(struct yt921x_priv *priv, const unsigned char *addr, u16 vid,
 	if (ctrl1 == val1 && ctrl2 == val2)
 		return 0;
 
-	return yt921x_fdb_add_index_in12(priv, index, ctrl1, ctrl2);
+	res = yt921x_fdb_add_index_in12(priv, index, ctrl1, ctrl2);
+	if (res)
+		return res;
+
+	if ((val1 & YT921X_FDB_IO1_STATUS_M) !=
+	    YT921X_FDB_IO1_STATUS_STATIC)
+		priv->fdb_static_cnt++;
+	return 0;
 }
 
 static int
@@ -2154,6 +2172,8 @@ static void yt921x_dsa_teardown(struct dsa_switch *ds)
 
 	yt921x_leds_remove(priv);
 #endif
+
+	dsa_devlink_resources_unregister(ds);
 }
 
 static int yt921x_chip_detect(struct yt921x_priv *priv)
@@ -2488,6 +2508,10 @@ static int yt921x_dsa_setup(struct dsa_switch *ds)
 	if (res)
 		return res;
 
+	res = yt921x_devlink_setup(priv);
+	if (res)
+		return res;
+
 #if IS_ENABLED(CONFIG_NET_DSA_YT921X_LEDS)
 	res = yt921x_leds_setup(priv);
 	if (res)
@@ -2576,6 +2600,7 @@ static const struct dsa_switch_ops yt921x_dsa_switch_ops = {
 	.port_add_dscp_prio	= yt921x_dsa_port_add_dscp_prio,
 #endif
 	/* chip */
+	.devlink_info_get	= yt921x_dsa_devlink_info_get,
 	.teardown		= yt921x_dsa_teardown,
 	.setup			= yt921x_dsa_setup,
 };
diff --git a/drivers/net/dsa/motorcomm/chip.h b/drivers/net/dsa/motorcomm/chip.h
index fc315f1d8f87..5408ec268ba0 100644
--- a/drivers/net/dsa/motorcomm/chip.h
+++ b/drivers/net/dsa/motorcomm/chip.h
@@ -248,6 +248,7 @@ enum yt921x_app_selector {
 #define   YT921X_PORT_LEARN_MODE_AUTO			YT921X_PORT_LEARN_MODE(0)
 #define   YT921X_PORT_LEARN_MODE_AUTO_AND_COPY		YT921X_PORT_LEARN_MODE(1)
 #define   YT921X_PORT_LEARN_MODE_CPU_CONTROL		YT921X_PORT_LEARN_MODE(2)
+#define YT921X_LEARN_UCAST_CNT		0x18043c
 #define YT921X_AGEING			0x180440
 #define  YT921X_AGEING_INTERVAL_M		GENMASK(15, 0)
 #define YT921X_FDB_IN0			0x180454
@@ -312,6 +313,7 @@ enum yt921x_app_selector {
 #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_LEARN_MCAST_CNT		0x180504
 #define YT921X_FILTER_UNK_UCAST		0x180508
 #define YT921X_FILTER_UNK_MCAST		0x18050c
 #define YT921X_FILTER_MCAST		0x180510
@@ -525,6 +527,7 @@ struct yt921x_priv {
 	struct yt921x_port ports[YT921X_PORT_NUM];
 
 	u16 eee_ports_mask;
+	unsigned short fdb_static_cnt;
 
 	DECLARE_BITMAP(meters_map, YT921X_METER_NUM);
 
diff --git a/drivers/net/dsa/motorcomm/devlink.c b/drivers/net/dsa/motorcomm/devlink.c
new file mode 100644
index 000000000000..cddc77a6fd11
--- /dev/null
+++ b/drivers/net/dsa/motorcomm/devlink.c
@@ -0,0 +1,208 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2026 David Yang
+ */
+
+#include "chip.h"
+#include "devlink.h"
+#include "smi.h"
+#include "tc.h"
+
+#define to_yt921x_priv(_ds) container_of_const(_ds, struct yt921x_priv, ds)
+
+int
+yt921x_dsa_devlink_info_get(struct dsa_switch *ds, struct devlink_info_req *req,
+			    struct netlink_ext_ack *extack)
+{
+	struct yt921x_priv *priv = to_yt921x_priv(ds);
+	int res;
+
+	if (!priv->info)
+		return -ENODEV;
+
+	res = devlink_info_version_fixed_put(req,
+					     DEVLINK_INFO_VERSION_GENERIC_ASIC_ID,
+					     priv->info->name);
+	if (res)
+		return res;
+
+	return 0;
+}
+
+static u64 yt921x_devlink_occ_get_acl(void *ctx)
+{
+	struct yt921x_priv *priv = ctx;
+	u64 count = 0;
+
+	mutex_lock(&priv->reg_lock);
+	for (unsigned int i = 0; i < YT921X_ACL_BLK_NUM; i++)
+		count += hweight8(priv->acl_masks[i]);
+	mutex_unlock(&priv->reg_lock);
+
+	return count;
+}
+
+static u64 yt921x_devlink_occ_get_fdb_ucast(void *ctx)
+{
+	struct yt921x_priv *priv = ctx;
+	u32 val;
+	int res;
+
+	mutex_lock(&priv->reg_lock);
+	res = yt921x_reg_read(priv, YT921X_LEARN_UCAST_CNT, &val);
+	mutex_unlock(&priv->reg_lock);
+
+	if (res)
+		return 0;
+	return val;
+}
+
+static u64 yt921x_devlink_occ_get_fdb_mcast(void *ctx)
+{
+	struct yt921x_priv *priv = ctx;
+	u32 val;
+	int res;
+
+	mutex_lock(&priv->reg_lock);
+	res = yt921x_reg_read(priv, YT921X_LEARN_MCAST_CNT, &val);
+	mutex_unlock(&priv->reg_lock);
+
+	if (res)
+		return 0;
+	return val;
+}
+
+static u64 yt921x_devlink_occ_get_fdb_static(void *ctx)
+{
+	struct yt921x_priv *priv = ctx;
+
+	return READ_ONCE(priv->fdb_static_cnt);
+}
+
+static u64 yt921x_devlink_occ_get_fdb(void *ctx)
+{
+	struct yt921x_priv *priv = ctx;
+	u64 count = 0;
+	u32 val;
+	int res;
+
+	mutex_lock(&priv->reg_lock);
+
+	res = yt921x_reg_read(priv, YT921X_LEARN_UCAST_CNT, &val);
+	if (res)
+		goto end;
+	count += val;
+
+	res = yt921x_reg_read(priv, YT921X_LEARN_MCAST_CNT, &val);
+	if (res)
+		goto end;
+	count += val;
+
+	count += priv->fdb_static_cnt;
+
+end:
+	mutex_unlock(&priv->reg_lock);
+
+	if (res)
+		return 0;
+	return count;
+}
+
+static u64 yt921x_devlink_occ_get_meter(void *ctx)
+{
+	struct yt921x_priv *priv = ctx;
+	u64 count;
+
+	mutex_lock(&priv->reg_lock);
+	count = bitmap_weight(priv->meters_map, YT921X_METER_NUM);
+	mutex_unlock(&priv->reg_lock);
+
+	return count;
+}
+
+enum yt921x_devlink_resource_id {
+	YT921X_DEVLINK_RESOURCE_ID_NONE,  /* DEVLINK_RESOURCE_ID_PARENT_TOP */
+	YT921X_DEVLINK_RESOURCE_ID_ACL,
+	YT921X_DEVLINK_RESOURCE_ID_FDB,
+	YT921X_DEVLINK_RESOURCE_ID_FDB_UCAST,
+	YT921X_DEVLINK_RESOURCE_ID_FDB_MCAST,
+	YT921X_DEVLINK_RESOURCE_ID_FDB_STATIC,
+	YT921X_DEVLINK_RESOURCE_ID_METER,
+};
+
+struct yt921x_devlink_resource {
+	const char *name;
+	devlink_resource_occ_get_t *occ_get;
+	unsigned short size;
+	unsigned char id;
+	unsigned char parent_id;
+};
+
+static const struct yt921x_devlink_resource yt921x_devlink_resources[] = {
+	{
+		"ACLs", yt921x_devlink_occ_get_acl,
+		YT921X_ACL_NUM,
+		YT921X_DEVLINK_RESOURCE_ID_ACL,
+		DEVLINK_RESOURCE_ID_PARENT_TOP,
+	},
+	{
+		"FDBs", yt921x_devlink_occ_get_fdb,
+		YT921X_FDB_NUM,
+		YT921X_DEVLINK_RESOURCE_ID_FDB,
+		DEVLINK_RESOURCE_ID_PARENT_TOP,
+	},
+	{
+		"ucast", yt921x_devlink_occ_get_fdb_ucast,
+		YT921X_FDB_NUM,
+		YT921X_DEVLINK_RESOURCE_ID_FDB_UCAST,
+		YT921X_DEVLINK_RESOURCE_ID_FDB,
+	},
+	{
+		"mcast", yt921x_devlink_occ_get_fdb_mcast,
+		YT921X_FDB_NUM,
+		YT921X_DEVLINK_RESOURCE_ID_FDB_MCAST,
+		YT921X_DEVLINK_RESOURCE_ID_FDB,
+	},
+	{
+		"static", yt921x_devlink_occ_get_fdb_static,
+		YT921X_FDB_NUM,
+		YT921X_DEVLINK_RESOURCE_ID_FDB_STATIC,
+		YT921X_DEVLINK_RESOURCE_ID_FDB,
+	},
+	{
+		"meters", yt921x_devlink_occ_get_meter,
+		YT921X_METER_NUM,
+		YT921X_DEVLINK_RESOURCE_ID_METER,
+		DEVLINK_RESOURCE_ID_PARENT_TOP,
+	},
+};
+
+int yt921x_devlink_setup(struct yt921x_priv *priv)
+{
+	struct dsa_switch *ds = &priv->ds;
+	int res;
+
+	for (unsigned int i = 0; i < ARRAY_SIZE(yt921x_devlink_resources);
+	     i++) {
+		struct devlink_resource_size_params size_params;
+		const struct yt921x_devlink_resource *r;
+
+		r = &yt921x_devlink_resources[i];
+
+		devlink_resource_size_params_init(&size_params, r->size,
+						  r->size, 1,
+						  DEVLINK_RESOURCE_UNIT_ENTRY);
+
+		res = dsa_devlink_resource_register(ds, r->name, r->size, r->id,
+						    r->parent_id, &size_params);
+		if (res) {
+			dsa_devlink_resources_unregister(ds);
+			return res;
+		}
+
+		dsa_devlink_resource_occ_get_register(ds, r->id, r->occ_get,
+						      priv);
+	}
+
+	return 0;
+}
diff --git a/drivers/net/dsa/motorcomm/devlink.h b/drivers/net/dsa/motorcomm/devlink.h
new file mode 100644
index 000000000000..e13fbe320bca
--- /dev/null
+++ b/drivers/net/dsa/motorcomm/devlink.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2026 David Yang
+ */
+
+#ifndef _YT_DEVLINK_H
+#define _YT_DEVLINK_H
+
+#include <net/dsa.h>
+
+int
+yt921x_dsa_devlink_info_get(struct dsa_switch *ds, struct devlink_info_req *req,
+			    struct netlink_ext_ack *extack);
+int yt921x_devlink_setup(struct yt921x_priv *priv);
+
+#endif
-- 
2.53.0