Merge branch 'mlxsw-Add-support-for-buffer-drop-traps'

Ido Schimmel says:

====================
mlxsw: Add support for buffer drop traps

Petr says:

A recent patch set added the ability to mirror buffer related drops
(e.g., early drops) through a netdev. This patch set adds the ability to
trap such packets to the local CPU for analysis.

The trapping towards the CPU is configured by using tc-trap action
instead of tc-mirred as was done when the packets were mirrored through
a netdev. A future patch set will also add the ability to sample the
dropped packets using tc-sample action.

The buffer related drop traps are added to devlink, which means that the
dropped packets can be reported to user space via the kernel's
drop_monitor module.

Patch set overview:

Patch #1 adds the early_drop trap to devlink

Patch #2 adds extack to a few devlink operations to facilitate better
error reporting to user space. This is necessary - among other things -
because the action of buffer drop traps cannot be changed in mlxsw

Patch #3 performs a small refactoring in mlxsw, patch #4 fixes a bug that
this patchset would trigger.

Patches #5-#6 add the infrastructure required to support different traps
/ trap groups in mlxsw per-ASIC. This is required because buffer drop
traps are not supported by Spectrum-1

Patch #7 extends mlxsw to register the early_drop trap

Patch #8 adds the offload logic for the "trap" action at a qevent block.

Patch #9 adds a mlxsw-specific selftest.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/devlink/devlink-trap.rst

@@ -405,6 +405,10 @@ be added to the following table:
      - ``control``
      - Traps packets logged during processing of flow action trap (e.g., via
        tc's trap action)
+   * - ``early_drop``
+     - ``drop``
+     - Traps packets dropped due to the RED (Random Early Detection) algorithm
+       (i.e., early drops)
 
 Driver-specific Packet Traps
 ============================

drivers/net/ethernet/mellanox/mlxsw/core.c

@@ -1177,14 +1177,15 @@ static void mlxsw_devlink_trap_fini(struct devlink *devlink,
 
 static int mlxsw_devlink_trap_action_set(struct devlink *devlink,
 					 const struct devlink_trap *trap,
-					 enum devlink_trap_action action)
+					 enum devlink_trap_action action,
+					 struct netlink_ext_ack *extack)
 {
 	struct mlxsw_core *mlxsw_core = devlink_priv(devlink);
 	struct mlxsw_driver *mlxsw_driver = mlxsw_core->driver;
 
 	if (!mlxsw_driver->trap_action_set)
 		return -EOPNOTSUPP;
-	return mlxsw_driver->trap_action_set(mlxsw_core, trap, action);
+	return mlxsw_driver->trap_action_set(mlxsw_core, trap, action, extack);
 }
 
 static int
@@ -1202,14 +1203,15 @@ mlxsw_devlink_trap_group_init(struct devlink *devlink,
 static int
 mlxsw_devlink_trap_group_set(struct devlink *devlink,
 			     const struct devlink_trap_group *group,
-			     const struct devlink_trap_policer *policer)
+			     const struct devlink_trap_policer *policer,
+			     struct netlink_ext_ack *extack)
 {
 	struct mlxsw_core *mlxsw_core = devlink_priv(devlink);
 	struct mlxsw_driver *mlxsw_driver = mlxsw_core->driver;
 
 	if (!mlxsw_driver->trap_group_set)
 		return -EOPNOTSUPP;
-	return mlxsw_driver->trap_group_set(mlxsw_core, group, policer);
+	return mlxsw_driver->trap_group_set(mlxsw_core, group, policer, extack);
 }
 
 static int

drivers/net/ethernet/mellanox/mlxsw/core.h

@@ -89,13 +89,15 @@ struct mlxsw_listener {
 };
 
 #define __MLXSW_RXL(_func, _trap_id, _en_action, _is_ctrl, _en_trap_group,	\
-		    _dis_action, _enabled_on_register, _dis_trap_group)		\
+		    _dis_action, _enabled_on_register, _dis_trap_group,		\
+		    _mirror_reason)						\
 	{									\
 		.trap_id = MLXSW_TRAP_ID_##_trap_id,				\
 		.rx_listener =							\
 		{								\
 			.func = _func,						\
 			.local_port = MLXSW_PORT_DONT_CARE,			\
+			.mirror_reason = _mirror_reason,			\
 			.trap_id = MLXSW_TRAP_ID_##_trap_id,			\
 		},								\
 		.en_action = MLXSW_REG_HPKT_ACTION_##_en_action,		\
@@ -109,12 +111,17 @@ struct mlxsw_listener {
 #define MLXSW_RXL(_func, _trap_id, _en_action, _is_ctrl, _trap_group,		\
 		  _dis_action)							\
 	__MLXSW_RXL(_func, _trap_id, _en_action, _is_ctrl, _trap_group,		\
-		    _dis_action, true, _trap_group)
+		    _dis_action, true, _trap_group, 0)
 
 #define MLXSW_RXL_DIS(_func, _trap_id, _en_action, _is_ctrl, _en_trap_group,	\
 		      _dis_action, _dis_trap_group)				\
 	__MLXSW_RXL(_func, _trap_id, _en_action, _is_ctrl, _en_trap_group,	\
-		    _dis_action, false, _dis_trap_group)
+		    _dis_action, false, _dis_trap_group, 0)
+
+#define MLXSW_RXL_MIRROR(_func, _session_id, _trap_group, _mirror_reason)	\
+	__MLXSW_RXL(_func, MIRROR_SESSION##_session_id,	TRAP_TO_CPU, false,	\
+		    _trap_group, TRAP_TO_CPU, true, _trap_group,		\
+		    _mirror_reason)
 
 #define MLXSW_EVENTL(_func, _trap_id, _trap_group)				\
 	{									\
@@ -326,12 +333,14 @@ struct mlxsw_driver {
 			  const struct devlink_trap *trap, void *trap_ctx);
 	int (*trap_action_set)(struct mlxsw_core *mlxsw_core,
 			       const struct devlink_trap *trap,
-			       enum devlink_trap_action action);
+			       enum devlink_trap_action action,
+			       struct netlink_ext_ack *extack);
 	int (*trap_group_init)(struct mlxsw_core *mlxsw_core,
 			       const struct devlink_trap_group *group);
 	int (*trap_group_set)(struct mlxsw_core *mlxsw_core,
 			      const struct devlink_trap_group *group,
-			      const struct devlink_trap_policer *policer);
+			      const struct devlink_trap_policer *policer,
+			      struct netlink_ext_ack *extack);
 	int (*trap_policer_init)(struct mlxsw_core *mlxsw_core,
 				 const struct devlink_trap_policer *policer);
 	void (*trap_policer_fini)(struct mlxsw_core *mlxsw_core,

drivers/net/ethernet/mellanox/mlxsw/reg.h

@@ -5614,6 +5614,7 @@ enum mlxsw_reg_htgt_trap_group {
 	MLXSW_REG_HTGT_TRAP_GROUP_SP_L3_EXCEPTIONS,
 	MLXSW_REG_HTGT_TRAP_GROUP_SP_TUNNEL_DISCARDS,
 	MLXSW_REG_HTGT_TRAP_GROUP_SP_ACL_DISCARDS,
+	MLXSW_REG_HTGT_TRAP_GROUP_SP_BUFFER_DISCARDS,
 
 	__MLXSW_REG_HTGT_TRAP_GROUP_MAX,
 	MLXSW_REG_HTGT_TRAP_GROUP_MAX = __MLXSW_REG_HTGT_TRAP_GROUP_MAX - 1

drivers/net/ethernet/mellanox/mlxsw/spectrum.c

@@ -3055,6 +3055,7 @@ static int mlxsw_sp1_init(struct mlxsw_core *mlxsw_core,
 	mlxsw_sp->ptp_ops = &mlxsw_sp1_ptp_ops;
 	mlxsw_sp->span_ops = &mlxsw_sp1_span_ops;
 	mlxsw_sp->policer_core_ops = &mlxsw_sp1_policer_core_ops;
+	mlxsw_sp->trap_ops = &mlxsw_sp1_trap_ops;
 	mlxsw_sp->listeners = mlxsw_sp1_listener;
 	mlxsw_sp->listeners_count = ARRAY_SIZE(mlxsw_sp1_listener);
 	mlxsw_sp->lowest_shaper_bs = MLXSW_REG_QEEC_LOWEST_SHAPER_BS_SP1;
@@ -3084,6 +3085,7 @@ static int mlxsw_sp2_init(struct mlxsw_core *mlxsw_core,
 	mlxsw_sp->ptp_ops = &mlxsw_sp2_ptp_ops;
 	mlxsw_sp->span_ops = &mlxsw_sp2_span_ops;
 	mlxsw_sp->policer_core_ops = &mlxsw_sp2_policer_core_ops;
+	mlxsw_sp->trap_ops = &mlxsw_sp2_trap_ops;
 	mlxsw_sp->lowest_shaper_bs = MLXSW_REG_QEEC_LOWEST_SHAPER_BS_SP2;
 
 	return mlxsw_sp_init(mlxsw_core, mlxsw_bus_info, extack);
@@ -3111,6 +3113,7 @@ static int mlxsw_sp3_init(struct mlxsw_core *mlxsw_core,
 	mlxsw_sp->ptp_ops = &mlxsw_sp2_ptp_ops;
 	mlxsw_sp->span_ops = &mlxsw_sp3_span_ops;
 	mlxsw_sp->policer_core_ops = &mlxsw_sp2_policer_core_ops;
+	mlxsw_sp->trap_ops = &mlxsw_sp2_trap_ops;
 	mlxsw_sp->lowest_shaper_bs = MLXSW_REG_QEEC_LOWEST_SHAPER_BS_SP3;
 
 	return mlxsw_sp_init(mlxsw_core, mlxsw_bus_info, extack);

drivers/net/ethernet/mellanox/mlxsw/spectrum.h

@@ -177,6 +177,7 @@ struct mlxsw_sp {
 	const struct mlxsw_sp_ptp_ops *ptp_ops;
 	const struct mlxsw_sp_span_ops *span_ops;
 	const struct mlxsw_sp_policer_core_ops *policer_core_ops;
+	const struct mlxsw_sp_trap_ops *trap_ops;
 	const struct mlxsw_listener *listeners;
 	size_t listeners_count;
 	u32 lowest_shaper_bs;
@@ -983,6 +984,10 @@ struct mlxsw_sp_mall_mirror_entry {
 	int span_id;
 };
 
+struct mlxsw_sp_mall_trap_entry {
+	int span_id;
+};
+
 struct mlxsw_sp_mall_entry {
 	struct list_head list;
 	unsigned long cookie;
@@ -991,6 +996,7 @@ struct mlxsw_sp_mall_entry {
 	bool ingress;
 	union {
 		struct mlxsw_sp_mall_mirror_entry mirror;
+		struct mlxsw_sp_mall_trap_entry trap;
 		struct mlxsw_sp_port_sample sample;
 	};
 	struct rcu_head rcu;
@@ -1177,12 +1183,14 @@ void mlxsw_sp_trap_fini(struct mlxsw_core *mlxsw_core,
 			const struct devlink_trap *trap, void *trap_ctx);
 int mlxsw_sp_trap_action_set(struct mlxsw_core *mlxsw_core,
 			     const struct devlink_trap *trap,
-			     enum devlink_trap_action action);
+			     enum devlink_trap_action action,
+			     struct netlink_ext_ack *extack);
 int mlxsw_sp_trap_group_init(struct mlxsw_core *mlxsw_core,
 			     const struct devlink_trap_group *group);
 int mlxsw_sp_trap_group_set(struct mlxsw_core *mlxsw_core,
 			    const struct devlink_trap_group *group,
-			    const struct devlink_trap_policer *policer);
+			    const struct devlink_trap_policer *policer,
+			    struct netlink_ext_ack *extack);
 int
 mlxsw_sp_trap_policer_init(struct mlxsw_core *mlxsw_core,
 			   const struct devlink_trap_policer *policer);
@@ -1196,6 +1204,8 @@ int
 mlxsw_sp_trap_policer_counter_get(struct mlxsw_core *mlxsw_core,
 				  const struct devlink_trap_policer *policer,
 				  u64 *p_drops);
+int mlxsw_sp_trap_group_policer_hw_id_get(struct mlxsw_sp *mlxsw_sp, u16 id,
+					  bool *p_enabled, u16 *p_hw_id);
 
 static inline struct net *mlxsw_sp_net(struct mlxsw_sp *mlxsw_sp)
 {

drivers/net/ethernet/mellanox/mlxsw/spectrum_qdisc.c

@@ -1289,19 +1289,18 @@ struct mlxsw_sp_qevent_binding {
 
 static LIST_HEAD(mlxsw_sp_qevent_block_cb_list);
 
-static int mlxsw_sp_qevent_mirror_configure(struct mlxsw_sp *mlxsw_sp,
+static int mlxsw_sp_qevent_span_configure(struct mlxsw_sp *mlxsw_sp,
 					  struct mlxsw_sp_mall_entry *mall_entry,
-					    struct mlxsw_sp_qevent_binding *qevent_binding)
+					  struct mlxsw_sp_qevent_binding *qevent_binding,
+					  const struct mlxsw_sp_span_agent_parms *agent_parms,
+					  int *p_span_id)
 {
 	struct mlxsw_sp_port *mlxsw_sp_port = qevent_binding->mlxsw_sp_port;
 	struct mlxsw_sp_span_trigger_parms trigger_parms = {};
-	struct mlxsw_sp_span_agent_parms agent_parms = {
-		.to_dev = mall_entry->mirror.to_dev,
-	};
 	int span_id;
 	int err;
 
-	err = mlxsw_sp_span_agent_get(mlxsw_sp, &span_id, &agent_parms);
+	err = mlxsw_sp_span_agent_get(mlxsw_sp, &span_id, agent_parms);
 	if (err)
 		return err;
 
@@ -1320,7 +1319,7 @@ static int mlxsw_sp_qevent_mirror_configure(struct mlxsw_sp *mlxsw_sp,
 	if (err)
 		goto err_trigger_enable;
 
-	mall_entry->mirror.span_id = span_id;
+	*p_span_id = span_id;
 	return 0;
 
 err_trigger_enable:
@@ -1333,13 +1332,13 @@ static int mlxsw_sp_qevent_mirror_configure(struct mlxsw_sp *mlxsw_sp,
 	return err;
 }
 
-static void mlxsw_sp_qevent_mirror_deconfigure(struct mlxsw_sp *mlxsw_sp,
-					       struct mlxsw_sp_mall_entry *mall_entry,
-					       struct mlxsw_sp_qevent_binding *qevent_binding)
+static void mlxsw_sp_qevent_span_deconfigure(struct mlxsw_sp *mlxsw_sp,
+					     struct mlxsw_sp_qevent_binding *qevent_binding,
+					     int span_id)
 {
 	struct mlxsw_sp_port *mlxsw_sp_port = qevent_binding->mlxsw_sp_port;
 	struct mlxsw_sp_span_trigger_parms trigger_parms = {
-		.span_id = mall_entry->mirror.span_id,
+		.span_id = span_id,
 	};
 
 	mlxsw_sp_span_trigger_disable(mlxsw_sp_port, qevent_binding->span_trigger,
@@ -1347,7 +1346,51 @@ static void mlxsw_sp_qevent_mirror_deconfigure(struct mlxsw_sp *mlxsw_sp,
 	mlxsw_sp_span_agent_unbind(mlxsw_sp, qevent_binding->span_trigger, mlxsw_sp_port,
 				   &trigger_parms);
 	mlxsw_sp_span_analyzed_port_put(mlxsw_sp_port, true);
-	mlxsw_sp_span_agent_put(mlxsw_sp, mall_entry->mirror.span_id);
+	mlxsw_sp_span_agent_put(mlxsw_sp, span_id);
+}
+
+static int mlxsw_sp_qevent_mirror_configure(struct mlxsw_sp *mlxsw_sp,
+					    struct mlxsw_sp_mall_entry *mall_entry,
+					    struct mlxsw_sp_qevent_binding *qevent_binding)
+{
+	struct mlxsw_sp_span_agent_parms agent_parms = {
+		.to_dev = mall_entry->mirror.to_dev,
+	};
+
+	return mlxsw_sp_qevent_span_configure(mlxsw_sp, mall_entry, qevent_binding,
+					      &agent_parms, &mall_entry->mirror.span_id);
+}
+
+static void mlxsw_sp_qevent_mirror_deconfigure(struct mlxsw_sp *mlxsw_sp,
+					       struct mlxsw_sp_mall_entry *mall_entry,
+					       struct mlxsw_sp_qevent_binding *qevent_binding)
+{
+	mlxsw_sp_qevent_span_deconfigure(mlxsw_sp, qevent_binding, mall_entry->mirror.span_id);
+}
+
+static int mlxsw_sp_qevent_trap_configure(struct mlxsw_sp *mlxsw_sp,
+					  struct mlxsw_sp_mall_entry *mall_entry,
+					  struct mlxsw_sp_qevent_binding *qevent_binding)
+{
+	struct mlxsw_sp_span_agent_parms agent_parms = {};
+	int err;
+
+	err = mlxsw_sp_trap_group_policer_hw_id_get(mlxsw_sp,
+						    DEVLINK_TRAP_GROUP_GENERIC_ID_BUFFER_DROPS,
+						    &agent_parms.policer_enable,
+						    &agent_parms.policer_id);
+	if (err)
+		return err;
+
+	return mlxsw_sp_qevent_span_configure(mlxsw_sp, mall_entry, qevent_binding,
+					      &agent_parms, &mall_entry->trap.span_id);
+}
+
+static void mlxsw_sp_qevent_trap_deconfigure(struct mlxsw_sp *mlxsw_sp,
+					     struct mlxsw_sp_mall_entry *mall_entry,
+					     struct mlxsw_sp_qevent_binding *qevent_binding)
+{
+	mlxsw_sp_qevent_span_deconfigure(mlxsw_sp, qevent_binding, mall_entry->trap.span_id);
 }
 
 static int mlxsw_sp_qevent_entry_configure(struct mlxsw_sp *mlxsw_sp,
@@ -1357,6 +1400,8 @@ static int mlxsw_sp_qevent_entry_configure(struct mlxsw_sp *mlxsw_sp,
 	switch (mall_entry->type) {
 	case MLXSW_SP_MALL_ACTION_TYPE_MIRROR:
 		return mlxsw_sp_qevent_mirror_configure(mlxsw_sp, mall_entry, qevent_binding);
+	case MLXSW_SP_MALL_ACTION_TYPE_TRAP:
+		return mlxsw_sp_qevent_trap_configure(mlxsw_sp, mall_entry, qevent_binding);
 	default:
 		/* This should have been validated away. */
 		WARN_ON(1);
@@ -1371,6 +1416,8 @@ static void mlxsw_sp_qevent_entry_deconfigure(struct mlxsw_sp *mlxsw_sp,
 	switch (mall_entry->type) {
 	case MLXSW_SP_MALL_ACTION_TYPE_MIRROR:
 		return mlxsw_sp_qevent_mirror_deconfigure(mlxsw_sp, mall_entry, qevent_binding);
+	case MLXSW_SP_MALL_ACTION_TYPE_TRAP:
+		return mlxsw_sp_qevent_trap_deconfigure(mlxsw_sp, mall_entry, qevent_binding);
 	default:
 		WARN_ON(1);
 		return;
@@ -1490,6 +1537,8 @@ static int mlxsw_sp_qevent_mall_replace(struct mlxsw_sp *mlxsw_sp,
 	if (act->id == FLOW_ACTION_MIRRED) {
 		mall_entry->type = MLXSW_SP_MALL_ACTION_TYPE_MIRROR;
 		mall_entry->mirror.to_dev = act->dev;
+	} else if (act->id == FLOW_ACTION_TRAP) {
+		mall_entry->type = MLXSW_SP_MALL_ACTION_TYPE_TRAP;
 	} else {
 		NL_SET_ERR_MSG(f->common.extack, "Unsupported action");
 		err = -EOPNOTSUPP;

drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c

@@ -837,7 +837,8 @@ static int mlxsw_sp_span_policer_id_base_set(struct mlxsw_sp_span *span,
 
 static void mlxsw_sp_span_policer_id_base_unset(struct mlxsw_sp_span *span)
 {
-	refcount_dec(&span->policer_id_base_ref_count);
+	if (refcount_dec_and_test(&span->policer_id_base_ref_count))
+		span->policer_id_base = 0;
 }
 
 static struct mlxsw_sp_span_entry *

drivers/net/ethernet/mellanox/mlxsw/spectrum_trap.c

@@ -21,6 +21,7 @@ struct mlxsw_sp_trap_group_item {
 	struct devlink_trap_group group;
 	u16 hw_group_id;
 	u8 priority;
+	u8 fixed_policer:1; /* Whether policer binding can change */
 };
 
 #define MLXSW_SP_TRAP_LISTENERS_MAX 3
@@ -28,6 +29,7 @@ struct mlxsw_sp_trap_group_item {
 struct mlxsw_sp_trap_item {
 	struct devlink_trap trap;
 	struct mlxsw_listener listeners_arr[MLXSW_SP_TRAP_LISTENERS_MAX];
+	u8 is_source:1;
 };
 
 /* All driver-specific traps must be documented in
@@ -46,6 +48,11 @@ enum {
 
 #define MLXSW_SP_TRAP_METADATA DEVLINK_TRAP_METADATA_TYPE_F_IN_PORT
 
+enum {
+	/* Packet was early dropped. */
+	MLXSW_SP_MIRROR_REASON_INGRESS_WRED = 9,
+};
+
 static int mlxsw_sp_rx_listener(struct mlxsw_sp *mlxsw_sp, struct sk_buff *skb,
 				u8 local_port,
 				struct mlxsw_sp_port *mlxsw_sp_port)
@@ -222,6 +229,11 @@ static void mlxsw_sp_rx_sample_listener(struct sk_buff *skb, u8 local_port,
 			     DEVLINK_TRAP_GROUP_GENERIC_ID_##_group_id,	      \
 			     MLXSW_SP_TRAP_METADATA | (_metadata))
 
+#define MLXSW_SP_TRAP_BUFFER_DROP(_id)					      \
+	DEVLINK_TRAP_GENERIC(DROP, TRAP, _id,				      \
+			     DEVLINK_TRAP_GROUP_GENERIC_ID_BUFFER_DROPS,      \
+			     MLXSW_SP_TRAP_METADATA)
+
 #define MLXSW_SP_TRAP_DRIVER_DROP(_id, _group_id)			      \
 	DEVLINK_TRAP_DRIVER(DROP, DROP, DEVLINK_MLXSW_TRAP_ID_##_id,	      \
 			    DEVLINK_MLXSW_TRAP_NAME_##_id,		      \
@@ -248,6 +260,10 @@ static void mlxsw_sp_rx_sample_listener(struct sk_buff *skb, u8 local_port,
 		      TRAP_EXCEPTION_TO_CPU, false, SP_##_en_group_id,	      \
 		      SET_FW_DEFAULT, SP_##_dis_group_id)
 
+#define MLXSW_SP_RXL_BUFFER_DISCARD(_mirror_reason)			      \
+	MLXSW_RXL_MIRROR(mlxsw_sp_rx_drop_listener, 0, SP_BUFFER_DISCARDS,    \
+			 MLXSW_SP_MIRROR_REASON_##_mirror_reason)
+
 #define MLXSW_SP_RXL_EXCEPTION(_id, _group_id, _action)			      \
 	MLXSW_RXL(mlxsw_sp_rx_mark_listener, _id,			      \
 		   _action, false, SP_##_group_id, SET_FW_DEFAULT)
@@ -331,6 +347,9 @@ mlxsw_sp_trap_policer_items_arr[] = {
 	{
 		.policer = MLXSW_SP_TRAP_POLICER(19, 1024, 512),
 	},
+	{
+		.policer = MLXSW_SP_TRAP_POLICER(20, 10240, 4096),
+	},
 };
 
 static const struct mlxsw_sp_trap_group_item mlxsw_sp_trap_group_items_arr[] = {
@@ -1063,10 +1082,10 @@ static int mlxsw_sp_trap_dummy_group_init(struct mlxsw_sp *mlxsw_sp)
 
 static int mlxsw_sp_trap_policer_items_arr_init(struct mlxsw_sp *mlxsw_sp)
 {
+	size_t arr_size = ARRAY_SIZE(mlxsw_sp_trap_policer_items_arr);
 	size_t elem_size = sizeof(struct mlxsw_sp_trap_policer_item);
-	u64 arr_size = ARRAY_SIZE(mlxsw_sp_trap_policer_items_arr);
 	struct mlxsw_sp_trap *trap = mlxsw_sp->trap;
-	u64 free_policers = 0;
+	size_t free_policers = 0;
 	u32 last_id;
 	int i;
 
@@ -1159,6 +1178,43 @@ static void mlxsw_sp_trap_policers_fini(struct mlxsw_sp *mlxsw_sp)
 	mlxsw_sp_trap_policer_items_arr_fini(mlxsw_sp);
 }
 
+static int mlxsw_sp_trap_group_items_arr_init(struct mlxsw_sp *mlxsw_sp)
+{
+	size_t common_groups_count = ARRAY_SIZE(mlxsw_sp_trap_group_items_arr);
+	const struct mlxsw_sp_trap_group_item *spec_group_items_arr;
+	size_t elem_size = sizeof(struct mlxsw_sp_trap_group_item);
+	struct mlxsw_sp_trap *trap = mlxsw_sp->trap;
+	size_t groups_count, spec_groups_count;
+	int err;
+
+	err = mlxsw_sp->trap_ops->groups_init(mlxsw_sp, &spec_group_items_arr,
+					      &spec_groups_count);
+	if (err)
+		return err;
+
+	/* The group items array is created by concatenating the common trap
+	 * group items and the ASIC-specific trap group items.
+	 */
+	groups_count = common_groups_count + spec_groups_count;
+	trap->group_items_arr = kcalloc(groups_count, elem_size, GFP_KERNEL);
+	if (!trap->group_items_arr)
+		return -ENOMEM;
+
+	memcpy(trap->group_items_arr, mlxsw_sp_trap_group_items_arr,
+	       elem_size * common_groups_count);
+	memcpy(trap->group_items_arr + common_groups_count,
+	       spec_group_items_arr, elem_size * spec_groups_count);
+
+	trap->groups_count = groups_count;
+
+	return 0;
+}
+
+static void mlxsw_sp_trap_group_items_arr_fini(struct mlxsw_sp *mlxsw_sp)
+{
+	kfree(mlxsw_sp->trap->group_items_arr);
+}
+
 static int mlxsw_sp_trap_groups_init(struct mlxsw_sp *mlxsw_sp)
 {
 	struct devlink *devlink = priv_to_devlink(mlxsw_sp->core);
@@ -1166,13 +1222,9 @@ static int mlxsw_sp_trap_groups_init(struct mlxsw_sp *mlxsw_sp)
 	struct mlxsw_sp_trap *trap = mlxsw_sp->trap;
 	int err, i;
 
-	trap->group_items_arr = kmemdup(mlxsw_sp_trap_group_items_arr,
-					sizeof(mlxsw_sp_trap_group_items_arr),
-					GFP_KERNEL);
-	if (!trap->group_items_arr)
-		return -ENOMEM;
-
-	trap->groups_count = ARRAY_SIZE(mlxsw_sp_trap_group_items_arr);
+	err = mlxsw_sp_trap_group_items_arr_init(mlxsw_sp);
+	if (err)
+		return err;
 
 	for (i = 0; i < trap->groups_count; i++) {
 		group_item = &trap->group_items_arr[i];
@@ -1189,7 +1241,7 @@ static int mlxsw_sp_trap_groups_init(struct mlxsw_sp *mlxsw_sp)
 		group_item = &trap->group_items_arr[i];
 		devlink_trap_groups_unregister(devlink, &group_item->group, 1);
 	}
-	kfree(trap->group_items_arr);
+	mlxsw_sp_trap_group_items_arr_fini(mlxsw_sp);
 	return err;
 }
 
@@ -1205,7 +1257,7 @@ static void mlxsw_sp_trap_groups_fini(struct mlxsw_sp *mlxsw_sp)
 		group_item = &trap->group_items_arr[i];
 		devlink_trap_groups_unregister(devlink, &group_item->group, 1);
 	}
-	kfree(trap->group_items_arr);
+	mlxsw_sp_trap_group_items_arr_fini(mlxsw_sp);
 }
 
 static bool
@@ -1214,6 +1266,43 @@ mlxsw_sp_trap_listener_is_valid(const struct mlxsw_listener *listener)
 	return listener->trap_id != 0;
 }
 
+static int mlxsw_sp_trap_items_arr_init(struct mlxsw_sp *mlxsw_sp)
+{
+	size_t common_traps_count = ARRAY_SIZE(mlxsw_sp_trap_items_arr);
+	const struct mlxsw_sp_trap_item *spec_trap_items_arr;
+	size_t elem_size = sizeof(struct mlxsw_sp_trap_item);
+	struct mlxsw_sp_trap *trap = mlxsw_sp->trap;
+	size_t traps_count, spec_traps_count;
+	int err;
+
+	err = mlxsw_sp->trap_ops->traps_init(mlxsw_sp, &spec_trap_items_arr,
+					     &spec_traps_count);
+	if (err)
+		return err;
+
+	/* The trap items array is created by concatenating the common trap
+	 * items and the ASIC-specific trap items.
+	 */
+	traps_count = common_traps_count + spec_traps_count;
+	trap->trap_items_arr = kcalloc(traps_count, elem_size, GFP_KERNEL);
+	if (!trap->trap_items_arr)
+		return -ENOMEM;
+
+	memcpy(trap->trap_items_arr, mlxsw_sp_trap_items_arr,
+	       elem_size * common_traps_count);
+	memcpy(trap->trap_items_arr + common_traps_count,
+	       spec_trap_items_arr, elem_size * spec_traps_count);
+
+	trap->traps_count = traps_count;
+
+	return 0;
+}
+
+static void mlxsw_sp_trap_items_arr_fini(struct mlxsw_sp *mlxsw_sp)
+{
+	kfree(mlxsw_sp->trap->trap_items_arr);
+}
+
 static int mlxsw_sp_traps_init(struct mlxsw_sp *mlxsw_sp)
 {
 	struct devlink *devlink = priv_to_devlink(mlxsw_sp->core);
@@ -1221,13 +1310,9 @@ static int mlxsw_sp_traps_init(struct mlxsw_sp *mlxsw_sp)
 	const struct mlxsw_sp_trap_item *trap_item;
 	int err, i;
 
-	trap->trap_items_arr = kmemdup(mlxsw_sp_trap_items_arr,
-				       sizeof(mlxsw_sp_trap_items_arr),
-				       GFP_KERNEL);
-	if (!trap->trap_items_arr)
-		return -ENOMEM;
-
-	trap->traps_count = ARRAY_SIZE(mlxsw_sp_trap_items_arr);
+	err = mlxsw_sp_trap_items_arr_init(mlxsw_sp);
+	if (err)
+		return err;
 
 	for (i = 0; i < trap->traps_count; i++) {
 		trap_item = &trap->trap_items_arr[i];
@@ -1244,7 +1329,7 @@ static int mlxsw_sp_traps_init(struct mlxsw_sp *mlxsw_sp)
 		trap_item = &trap->trap_items_arr[i];
 		devlink_traps_unregister(devlink, &trap_item->trap, 1);
 	}
-	kfree(trap->trap_items_arr);
+	mlxsw_sp_trap_items_arr_fini(mlxsw_sp);
 	return err;
 }
 
@@ -1260,7 +1345,7 @@ static void mlxsw_sp_traps_fini(struct mlxsw_sp *mlxsw_sp)
 		trap_item = &trap->trap_items_arr[i];
 		devlink_traps_unregister(devlink, &trap_item->trap, 1);
 	}
-	kfree(trap->trap_items_arr);
+	mlxsw_sp_trap_items_arr_fini(mlxsw_sp);
 }
 
 int mlxsw_sp_devlink_traps_init(struct mlxsw_sp *mlxsw_sp)
@@ -1352,7 +1437,8 @@ void mlxsw_sp_trap_fini(struct mlxsw_core *mlxsw_core,
 
 int mlxsw_sp_trap_action_set(struct mlxsw_core *mlxsw_core,
 			     const struct devlink_trap *trap,
-			     enum devlink_trap_action action)
+			     enum devlink_trap_action action,
+			     struct netlink_ext_ack *extack)
 {
 	struct mlxsw_sp *mlxsw_sp = mlxsw_core_driver_priv(mlxsw_core);
 	const struct mlxsw_sp_trap_item *trap_item;
@@ -1362,6 +1448,11 @@ int mlxsw_sp_trap_action_set(struct mlxsw_core *mlxsw_core,
 	if (WARN_ON(!trap_item))
 		return -EINVAL;
 
+	if (trap_item->is_source) {
+		NL_SET_ERR_MSG_MOD(extack, "Changing the action of source traps is not supported");
+		return -EOPNOTSUPP;
+	}
+
 	for (i = 0; i < MLXSW_SP_TRAP_LISTENERS_MAX; i++) {
 		const struct mlxsw_listener *listener;
 		bool enabled;
@@ -1392,7 +1483,7 @@ int mlxsw_sp_trap_action_set(struct mlxsw_core *mlxsw_core,
 static int
 __mlxsw_sp_trap_group_init(struct mlxsw_core *mlxsw_core,
 			   const struct devlink_trap_group *group,
-			   u32 policer_id)
+			   u32 policer_id, struct netlink_ext_ack *extack)
 {
 	struct mlxsw_sp *mlxsw_sp = mlxsw_core_driver_priv(mlxsw_core);
 	u16 hw_policer_id = MLXSW_REG_HTGT_INVALID_POLICER;
@@ -1403,6 +1494,11 @@ __mlxsw_sp_trap_group_init(struct mlxsw_core *mlxsw_core,
 	if (WARN_ON(!group_item))
 		return -EINVAL;
 
+	if (group_item->fixed_policer && policer_id != group->init_policer_id) {
+		NL_SET_ERR_MSG_MOD(extack, "Changing the policer binding of this group is not supported");
+		return -EOPNOTSUPP;
+	}
+
 	if (policer_id) {
 		struct mlxsw_sp_trap_policer_item *policer_item;
 
@@ -1422,16 +1518,18 @@ int mlxsw_sp_trap_group_init(struct mlxsw_core *mlxsw_core,
 			     const struct devlink_trap_group *group)
 {
 	return __mlxsw_sp_trap_group_init(mlxsw_core, group,
-					  group->init_policer_id);
+					  group->init_policer_id, NULL);
 }
 
 int mlxsw_sp_trap_group_set(struct mlxsw_core *mlxsw_core,
 			    const struct devlink_trap_group *group,
-			    const struct devlink_trap_policer *policer)
+			    const struct devlink_trap_policer *policer,
+			    struct netlink_ext_ack *extack)
 {
 	u32 policer_id = policer ? policer->id : 0;
 
-	return __mlxsw_sp_trap_group_init(mlxsw_core, group, policer_id);
+	return __mlxsw_sp_trap_group_init(mlxsw_core, group, policer_id,
+					  extack);
 }
 
 static int
@@ -1576,3 +1674,110 @@ mlxsw_sp_trap_policer_counter_get(struct mlxsw_core *mlxsw_core,
 
 	return 0;
 }
+
+int mlxsw_sp_trap_group_policer_hw_id_get(struct mlxsw_sp *mlxsw_sp, u16 id,
+					  bool *p_enabled, u16 *p_hw_id)
+{
+	struct mlxsw_sp_trap_policer_item *pol_item;
+	struct mlxsw_sp_trap_group_item *gr_item;
+	u32 pol_id;
+
+	gr_item = mlxsw_sp_trap_group_item_lookup(mlxsw_sp, id);
+	if (!gr_item)
+		return -ENOENT;
+
+	pol_id = gr_item->group.init_policer_id;
+	if (!pol_id) {
+		*p_enabled = false;
+		return 0;
+	}
+
+	pol_item = mlxsw_sp_trap_policer_item_lookup(mlxsw_sp, pol_id);
+	if (WARN_ON(!pol_item))
+		return -ENOENT;
+
+	*p_enabled = true;
+	*p_hw_id = pol_item->hw_id;
+	return 0;
+}
+
+static const struct mlxsw_sp_trap_group_item
+mlxsw_sp1_trap_group_items_arr[] = {
+};
+
+static const struct mlxsw_sp_trap_item
+mlxsw_sp1_trap_items_arr[] = {
+};
+
+static int
+mlxsw_sp1_trap_groups_init(struct mlxsw_sp *mlxsw_sp,
+			   const struct mlxsw_sp_trap_group_item **arr,
+			   size_t *p_groups_count)
+{
+	*arr = mlxsw_sp1_trap_group_items_arr;
+	*p_groups_count = ARRAY_SIZE(mlxsw_sp1_trap_group_items_arr);
+
+	return 0;
+}
+
+static int mlxsw_sp1_traps_init(struct mlxsw_sp *mlxsw_sp,
+				const struct mlxsw_sp_trap_item **arr,
+				size_t *p_traps_count)
+{
+	*arr = mlxsw_sp1_trap_items_arr;
+	*p_traps_count = ARRAY_SIZE(mlxsw_sp1_trap_items_arr);
+
+	return 0;
+}
+
+const struct mlxsw_sp_trap_ops mlxsw_sp1_trap_ops = {
+	.groups_init = mlxsw_sp1_trap_groups_init,
+	.traps_init = mlxsw_sp1_traps_init,
+};
+
+static const struct mlxsw_sp_trap_group_item
+mlxsw_sp2_trap_group_items_arr[] = {
+	{
+		.group = DEVLINK_TRAP_GROUP_GENERIC(BUFFER_DROPS, 20),
+		.hw_group_id = MLXSW_REG_HTGT_TRAP_GROUP_SP_BUFFER_DISCARDS,
+		.priority = 0,
+		.fixed_policer = true,
+	},
+};
+
+static const struct mlxsw_sp_trap_item
+mlxsw_sp2_trap_items_arr[] = {
+	{
+		.trap = MLXSW_SP_TRAP_BUFFER_DROP(EARLY_DROP),
+		.listeners_arr = {
+			MLXSW_SP_RXL_BUFFER_DISCARD(INGRESS_WRED),
+		},
+		.is_source = true,
+	},
+};
+
+static int
+mlxsw_sp2_trap_groups_init(struct mlxsw_sp *mlxsw_sp,
+			   const struct mlxsw_sp_trap_group_item **arr,
+			   size_t *p_groups_count)
+{
+	*arr = mlxsw_sp2_trap_group_items_arr;
+	*p_groups_count = ARRAY_SIZE(mlxsw_sp2_trap_group_items_arr);
+
+	return 0;
+}
+
+static int mlxsw_sp2_traps_init(struct mlxsw_sp *mlxsw_sp,
+				const struct mlxsw_sp_trap_item **arr,
+				size_t *p_traps_count)
+{
+	*arr = mlxsw_sp2_trap_items_arr;
+	*p_traps_count = ARRAY_SIZE(mlxsw_sp2_trap_items_arr);
+
+	return 0;
+}
+
+const struct mlxsw_sp_trap_ops mlxsw_sp2_trap_ops = {
+	.groups_init = mlxsw_sp2_trap_groups_init,
+	.traps_init = mlxsw_sp2_traps_init,
+};

drivers/net/ethernet/mellanox/mlxsw/spectrum_trap.h

@@ -9,13 +9,13 @@
 
 struct mlxsw_sp_trap {
 	struct mlxsw_sp_trap_policer_item *policer_items_arr;
-	u64 policers_count; /* Number of registered policers */
+	size_t policers_count; /* Number of registered policers */
 
 	struct mlxsw_sp_trap_group_item *group_items_arr;
-	u64 groups_count; /* Number of registered groups */
+	size_t groups_count; /* Number of registered groups */
 
 	struct mlxsw_sp_trap_item *trap_items_arr;
-	u64 traps_count; /* Number of registered traps */
+	size_t traps_count; /* Number of registered traps */
 
 	u16 thin_policer_hw_id;
 
@@ -23,4 +23,16 @@ struct mlxsw_sp_trap {
 	unsigned long policers_usage[]; /* Usage bitmap */
 };
 
+struct mlxsw_sp_trap_ops {
+	int (*groups_init)(struct mlxsw_sp *mlxsw_sp,
+			   const struct mlxsw_sp_trap_group_item **arr,
+			   size_t *p_groups_count);
+	int (*traps_init)(struct mlxsw_sp *mlxsw_sp,
+			  const struct mlxsw_sp_trap_item **arr,
+			  size_t *p_traps_count);
+};
+
+extern const struct mlxsw_sp_trap_ops mlxsw_sp1_trap_ops;
+extern const struct mlxsw_sp_trap_ops mlxsw_sp2_trap_ops;
+
 #endif

drivers/net/netdevsim/dev.c

@@ -810,7 +810,8 @@ static int nsim_dev_devlink_trap_init(struct devlink *devlink,
 static int
 nsim_dev_devlink_trap_action_set(struct devlink *devlink,
 				 const struct devlink_trap *trap,
-				 enum devlink_trap_action action)
+				 enum devlink_trap_action action,
+				 struct netlink_ext_ack *extack)
 {
 	struct nsim_dev *nsim_dev = devlink_priv(devlink);
 	struct nsim_trap_item *nsim_trap_item;
@@ -829,7 +830,8 @@ nsim_dev_devlink_trap_action_set(struct devlink *devlink,
 static int
 nsim_dev_devlink_trap_group_set(struct devlink *devlink,
 				const struct devlink_trap_group *group,
-				const struct devlink_trap_policer *policer)
+				const struct devlink_trap_policer *policer,
+				struct netlink_ext_ack *extack)
 {
 	struct nsim_dev *nsim_dev = devlink_priv(devlink);
 

include/net/devlink.h

@@ -703,6 +703,7 @@ enum devlink_trap_generic_id {
 	DEVLINK_TRAP_GENERIC_ID_PTP_GENERAL,
 	DEVLINK_TRAP_GENERIC_ID_FLOW_ACTION_SAMPLE,
 	DEVLINK_TRAP_GENERIC_ID_FLOW_ACTION_TRAP,
+	DEVLINK_TRAP_GENERIC_ID_EARLY_DROP,
 
 	/* Add new generic trap IDs above */
 	__DEVLINK_TRAP_GENERIC_ID_MAX,
@@ -891,6 +892,8 @@ enum devlink_trap_group_generic_id {
 	"flow_action_sample"
 #define DEVLINK_TRAP_GENERIC_NAME_FLOW_ACTION_TRAP \
 	"flow_action_trap"
+#define DEVLINK_TRAP_GENERIC_NAME_EARLY_DROP \
+	"early_drop"
 
 #define DEVLINK_TRAP_GROUP_GENERIC_NAME_L2_DROPS \
 	"l2_drops"
@@ -1074,7 +1077,8 @@ struct devlink_ops {
 	 */
 	int (*trap_action_set)(struct devlink *devlink,
 			       const struct devlink_trap *trap,
-			       enum devlink_trap_action action);
+			       enum devlink_trap_action action,
+			       struct netlink_ext_ack *extack);
 	/**
 	 * @trap_group_init: Trap group initialization function.
 	 *
@@ -1091,7 +1095,8 @@ struct devlink_ops {
 	 */
 	int (*trap_group_set)(struct devlink *devlink,
 			      const struct devlink_trap_group *group,
-			      const struct devlink_trap_policer *policer);
+			      const struct devlink_trap_policer *policer,
+			      struct netlink_ext_ack *extack);
 	/**
 	 * @trap_policer_init: Trap policer initialization function.
 	 *

net/core/devlink.c

@@ -6423,7 +6423,7 @@ static int __devlink_trap_action_set(struct devlink *devlink,
 	}
 
 	err = devlink->ops->trap_action_set(devlink, trap_item->trap,
-					    trap_action);
+					    trap_action, extack);
 	if (err)
 		return err;
 
@@ -6713,7 +6713,8 @@ static int devlink_trap_group_set(struct devlink *devlink,
 	}
 	policer = policer_item ? policer_item->policer : NULL;
 
-	err = devlink->ops->trap_group_set(devlink, group_item->group, policer);
+	err = devlink->ops->trap_group_set(devlink, group_item->group, policer,
+					   extack);
 	if (err)
 		return err;
 
@@ -8801,6 +8802,7 @@ static const struct devlink_trap devlink_trap_generic[] = {
 	DEVLINK_TRAP(PTP_GENERAL, CONTROL),
 	DEVLINK_TRAP(FLOW_ACTION_SAMPLE, CONTROL),
 	DEVLINK_TRAP(FLOW_ACTION_TRAP, CONTROL),
+	DEVLINK_TRAP(EARLY_DROP, DROP),
 };
 
 #define DEVLINK_TRAP_GROUP(_id)						      \
@@ -9050,7 +9052,8 @@ static void devlink_trap_disable(struct devlink *devlink,
 	if (WARN_ON_ONCE(!trap_item))
 		return;
 
-	devlink->ops->trap_action_set(devlink, trap, DEVLINK_TRAP_ACTION_DROP);
+	devlink->ops->trap_action_set(devlink, trap, DEVLINK_TRAP_ACTION_DROP,
+				      NULL);
 	trap_item->action = DEVLINK_TRAP_ACTION_DROP;
 }
 

tools/testing/selftests/drivers/net/mlxsw/sch_red_core.sh

@@ -568,17 +568,12 @@ do_drop_test()
 	busywait 1100 until_counter_is ">= $((base + 1))" $fetch_counter >/dev/null
 	check_fail $? "Spurious packets observed without buffer pressure"
 
-	qevent_rule_uninstall_$subtest
-
 	# Push to the queue until it's at the limit. The configured limit is
 	# rounded by the qdisc and then by the driver, so this is the best we
-	# can do to get to the real limit of the system. Do this with the rules
-	# uninstalled so that the inevitable drops don't get counted.
+	# can do to get to the real limit of the system.
 	build_backlog $vlan $((3 * limit / 2)) udp >/dev/null
 
-	qevent_rule_install_$subtest
 	base=$($fetch_counter)
-
 	send_packets $vlan udp 11
 
 	now=$(busywait 1100 until_counter_is ">= $((base + 10))" $fetch_counter)
@@ -631,3 +626,31 @@ do_drop_mirror_test()
 
 	tc filter del dev $h2 ingress pref 1 handle 101 flower
 }
+
+qevent_rule_install_trap()
+{
+	tc filter add block 10 pref 1234 handle 102 matchall skip_sw \
+	   action trap hw_stats disabled
+}
+
+qevent_rule_uninstall_trap()
+{
+	tc filter del block 10 pref 1234 handle 102 matchall
+}
+
+qevent_counter_fetch_trap()
+{
+	local trap_name=$1; shift
+
+	devlink_trap_rx_packets_get "$trap_name"
+}
+
+do_drop_trap_test()
+{
+	local vlan=$1; shift
+	local limit=$1; shift
+	local trap_name=$1; shift
+
+	do_drop_test "$vlan" "$limit" "$trap_name" trap \
+		     "qevent_counter_fetch_trap $trap_name"
+}

tools/testing/selftests/drivers/net/mlxsw/sch_red_ets.sh

@@ -8,6 +8,7 @@ ALL_TESTS="
 	red_test
 	mc_backlog_test
 	red_mirror_test
+	red_trap_test
 "
 : ${QDISC:=ets}
 source sch_red_core.sh
@@ -94,6 +95,16 @@ red_mirror_test()
 	uninstall_qdisc
 }
 
+red_trap_test()
+{
+	install_qdisc qevent early_drop block 10
+
+	do_drop_trap_test 10 $BACKLOG1 early_drop
+	do_drop_trap_test 11 $BACKLOG2 early_drop
+
+	uninstall_qdisc
+}
+
 trap cleanup EXIT
 
 setup_prepare