mlxsw: spectrum: Add devlink-trap support

Register supported packet traps (layer 2 drops only, currently) and
associated trap group with devlink during driver initialization.

The amount of traffic generated by these packet drop traps is capped at
10Kpps to ensure the CPU is not overwhelmed by incoming packets.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/Makefile

@@ -29,7 +29,7 @@ mlxsw_spectrum-objs		:= spectrum.o spectrum_buffers.o \
 				   spectrum_mr_tcam.o spectrum_mr.o \
 				   spectrum_qdisc.o spectrum_span.o \
 				   spectrum_nve.o spectrum_nve_vxlan.o \
-				   spectrum_dpipe.o
+				   spectrum_dpipe.o spectrum_trap.o
 mlxsw_spectrum-$(CONFIG_MLXSW_SPECTRUM_DCB)	+= spectrum_dcb.o
 mlxsw_spectrum-$(CONFIG_PTP_1588_CLOCK)		+= spectrum_ptp.o
 obj-$(CONFIG_MLXSW_MINIMAL)	+= mlxsw_minimal.o

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

@@ -1017,6 +1017,54 @@ static int mlxsw_devlink_flash_update(struct devlink *devlink,
 					  component, extack);
 }
 
+static int mlxsw_devlink_trap_init(struct devlink *devlink,
+				   const struct devlink_trap *trap,
+				   void *trap_ctx)
+{
+	struct mlxsw_core *mlxsw_core = devlink_priv(devlink);
+	struct mlxsw_driver *mlxsw_driver = mlxsw_core->driver;
+
+	if (!mlxsw_driver->trap_init)
+		return -EOPNOTSUPP;
+	return mlxsw_driver->trap_init(mlxsw_core, trap, trap_ctx);
+}
+
+static void mlxsw_devlink_trap_fini(struct devlink *devlink,
+				    const struct devlink_trap *trap,
+				    void *trap_ctx)
+{
+	struct mlxsw_core *mlxsw_core = devlink_priv(devlink);
+	struct mlxsw_driver *mlxsw_driver = mlxsw_core->driver;
+
+	if (!mlxsw_driver->trap_fini)
+		return;
+	mlxsw_driver->trap_fini(mlxsw_core, trap, trap_ctx);
+}
+
+static int mlxsw_devlink_trap_action_set(struct devlink *devlink,
+					 const struct devlink_trap *trap,
+					 enum devlink_trap_action action)
+{
+	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);
+}
+
+static int
+mlxsw_devlink_trap_group_init(struct devlink *devlink,
+			      const struct devlink_trap_group *group)
+{
+	struct mlxsw_core *mlxsw_core = devlink_priv(devlink);
+	struct mlxsw_driver *mlxsw_driver = mlxsw_core->driver;
+
+	if (!mlxsw_driver->trap_group_init)
+		return -EOPNOTSUPP;
+	return mlxsw_driver->trap_group_init(mlxsw_core, group);
+}
+
 static const struct devlink_ops mlxsw_devlink_ops = {
 	.reload				= mlxsw_devlink_core_bus_device_reload,
 	.port_type_set			= mlxsw_devlink_port_type_set,
@@ -1034,6 +1082,10 @@ static const struct devlink_ops mlxsw_devlink_ops = {
 	.sb_occ_tc_port_bind_get	= mlxsw_devlink_sb_occ_tc_port_bind_get,
 	.info_get			= mlxsw_devlink_info_get,
 	.flash_update			= mlxsw_devlink_flash_update,
+	.trap_init			= mlxsw_devlink_trap_init,
+	.trap_fini			= mlxsw_devlink_trap_fini,
+	.trap_action_set		= mlxsw_devlink_trap_action_set,
+	.trap_group_init		= mlxsw_devlink_trap_group_init,
 };
 
 static int

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

@@ -292,6 +292,15 @@ struct mlxsw_driver {
 	int (*flash_update)(struct mlxsw_core *mlxsw_core,
 			    const char *file_name, const char *component,
 			    struct netlink_ext_ack *extack);
+	int (*trap_init)(struct mlxsw_core *mlxsw_core,
+			 const struct devlink_trap *trap, void *trap_ctx);
+	void (*trap_fini)(struct mlxsw_core *mlxsw_core,
+			  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);
+	int (*trap_group_init)(struct mlxsw_core *mlxsw_core,
+			       const struct devlink_trap_group *group);
 	void (*txhdr_construct)(struct sk_buff *skb,
 				const struct mlxsw_tx_info *tx_info);
 	int (*resources_register)(struct mlxsw_core *mlxsw_core);

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

@@ -4665,6 +4665,12 @@ static int mlxsw_sp_init(struct mlxsw_core *mlxsw_core,
 		goto err_traps_init;
 	}
 
+	err = mlxsw_sp_devlink_traps_init(mlxsw_sp);
+	if (err) {
+		dev_err(mlxsw_sp->bus_info->dev, "Failed to initialize devlink traps\n");
+		goto err_devlink_traps_init;
+	}
+
 	err = mlxsw_sp_buffers_init(mlxsw_sp);
 	if (err) {
 		dev_err(mlxsw_sp->bus_info->dev, "Failed to initialize buffers\n");
@@ -4798,6 +4804,8 @@ static int mlxsw_sp_init(struct mlxsw_core *mlxsw_core,
 err_lag_init:
 	mlxsw_sp_buffers_fini(mlxsw_sp);
 err_buffers_init:
+	mlxsw_sp_devlink_traps_fini(mlxsw_sp);
+err_devlink_traps_init:
 	mlxsw_sp_traps_fini(mlxsw_sp);
 err_traps_init:
 	mlxsw_sp_fids_fini(mlxsw_sp);
@@ -4870,6 +4878,7 @@ static void mlxsw_sp_fini(struct mlxsw_core *mlxsw_core)
 	mlxsw_sp_span_fini(mlxsw_sp);
 	mlxsw_sp_lag_fini(mlxsw_sp);
 	mlxsw_sp_buffers_fini(mlxsw_sp);
+	mlxsw_sp_devlink_traps_fini(mlxsw_sp);
 	mlxsw_sp_traps_fini(mlxsw_sp);
 	mlxsw_sp_fids_fini(mlxsw_sp);
 	mlxsw_sp_kvdl_fini(mlxsw_sp);
@@ -5251,6 +5260,10 @@ static struct mlxsw_driver mlxsw_sp1_driver = {
 	.sb_occ_port_pool_get		= mlxsw_sp_sb_occ_port_pool_get,
 	.sb_occ_tc_port_bind_get	= mlxsw_sp_sb_occ_tc_port_bind_get,
 	.flash_update			= mlxsw_sp_flash_update,
+	.trap_init			= mlxsw_sp_trap_init,
+	.trap_fini			= mlxsw_sp_trap_fini,
+	.trap_action_set		= mlxsw_sp_trap_action_set,
+	.trap_group_init		= mlxsw_sp_trap_group_init,
 	.txhdr_construct		= mlxsw_sp_txhdr_construct,
 	.resources_register		= mlxsw_sp1_resources_register,
 	.kvd_sizes_get			= mlxsw_sp_kvd_sizes_get,
@@ -5281,6 +5294,10 @@ static struct mlxsw_driver mlxsw_sp2_driver = {
 	.sb_occ_port_pool_get		= mlxsw_sp_sb_occ_port_pool_get,
 	.sb_occ_tc_port_bind_get	= mlxsw_sp_sb_occ_tc_port_bind_get,
 	.flash_update			= mlxsw_sp_flash_update,
+	.trap_init			= mlxsw_sp_trap_init,
+	.trap_fini			= mlxsw_sp_trap_fini,
+	.trap_action_set		= mlxsw_sp_trap_action_set,
+	.trap_group_init		= mlxsw_sp_trap_group_init,
 	.txhdr_construct		= mlxsw_sp_txhdr_construct,
 	.resources_register		= mlxsw_sp2_resources_register,
 	.params_register		= mlxsw_sp2_params_register,
@@ -5310,6 +5327,10 @@ static struct mlxsw_driver mlxsw_sp3_driver = {
 	.sb_occ_port_pool_get		= mlxsw_sp_sb_occ_port_pool_get,
 	.sb_occ_tc_port_bind_get	= mlxsw_sp_sb_occ_tc_port_bind_get,
 	.flash_update			= mlxsw_sp_flash_update,
+	.trap_init			= mlxsw_sp_trap_init,
+	.trap_fini			= mlxsw_sp_trap_fini,
+	.trap_action_set		= mlxsw_sp_trap_action_set,
+	.trap_group_init		= mlxsw_sp_trap_group_init,
 	.txhdr_construct		= mlxsw_sp_txhdr_construct,
 	.resources_register		= mlxsw_sp2_resources_register,
 	.params_register		= mlxsw_sp2_params_register,

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

@@ -958,4 +958,17 @@ void mlxsw_sp_nve_fini(struct mlxsw_sp *mlxsw_sp);
 int mlxsw_sp_nve_inc_parsing_depth_get(struct mlxsw_sp *mlxsw_sp);
 void mlxsw_sp_nve_inc_parsing_depth_put(struct mlxsw_sp *mlxsw_sp);
 
+/* spectrum_trap.c */
+int mlxsw_sp_devlink_traps_init(struct mlxsw_sp *mlxsw_sp);
+void mlxsw_sp_devlink_traps_fini(struct mlxsw_sp *mlxsw_sp);
+int mlxsw_sp_trap_init(struct mlxsw_core *mlxsw_core,
+		       const struct devlink_trap *trap, void *trap_ctx);
+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);
+int mlxsw_sp_trap_group_init(struct mlxsw_core *mlxsw_core,
+			     const struct devlink_trap_group *group);
+
 #endif

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

+// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
+/* Copyright (c) 2019 Mellanox Technologies. All rights reserved */
+
+#include <linux/kernel.h>
+#include <net/devlink.h>
+#include <uapi/linux/devlink.h>
+
+#include "core.h"
+#include "reg.h"
+#include "spectrum.h"
+
+#define MLXSW_SP_TRAP_METADATA DEVLINK_TRAP_METADATA_TYPE_F_IN_PORT
+
+static void mlxsw_sp_rx_drop_listener(struct sk_buff *skb, u8 local_port,
+				      void *priv);
+
+#define MLXSW_SP_TRAP_DROP(_id, _group_id)				      \
+	DEVLINK_TRAP_GENERIC(DROP, DROP, _id,				      \
+			     DEVLINK_TRAP_GROUP_GENERIC(_group_id),	      \
+			     MLXSW_SP_TRAP_METADATA)
+
+#define MLXSW_SP_RXL_DISCARD(_id, _group_id)				      \
+	MLXSW_RXL(mlxsw_sp_rx_drop_listener, DISCARD_##_id, SET_FW_DEFAULT,   \
+		  false, SP_##_group_id, DISCARD)
+
+static struct devlink_trap mlxsw_sp_traps_arr[] = {
+	MLXSW_SP_TRAP_DROP(SMAC_MC, L2_DROPS),
+	MLXSW_SP_TRAP_DROP(VLAN_TAG_MISMATCH, L2_DROPS),
+	MLXSW_SP_TRAP_DROP(INGRESS_VLAN_FILTER, L2_DROPS),
+	MLXSW_SP_TRAP_DROP(INGRESS_STP_FILTER, L2_DROPS),
+	MLXSW_SP_TRAP_DROP(EMPTY_TX_LIST, L2_DROPS),
+	MLXSW_SP_TRAP_DROP(PORT_LOOPBACK_FILTER, L2_DROPS),
+};
+
+static struct mlxsw_listener mlxsw_sp_listeners_arr[] = {
+	MLXSW_SP_RXL_DISCARD(ING_PACKET_SMAC_MC, L2_DISCARDS),
+	MLXSW_SP_RXL_DISCARD(ING_SWITCH_VTAG_ALLOW, L2_DISCARDS),
+	MLXSW_SP_RXL_DISCARD(ING_SWITCH_VLAN, L2_DISCARDS),
+	MLXSW_SP_RXL_DISCARD(ING_SWITCH_STP, L2_DISCARDS),
+	MLXSW_SP_RXL_DISCARD(LOOKUP_SWITCH_UC, L2_DISCARDS),
+	MLXSW_SP_RXL_DISCARD(LOOKUP_SWITCH_MC_NULL, L2_DISCARDS),
+	MLXSW_SP_RXL_DISCARD(LOOKUP_SWITCH_LB, L2_DISCARDS),
+};
+
+/* Mapping between hardware trap and devlink trap. Multiple hardware traps can
+ * be mapped to the same devlink trap. Order is according to
+ * 'mlxsw_sp_listeners_arr'.
+ */
+static u16 mlxsw_sp_listener_devlink_map[] = {
+	DEVLINK_TRAP_GENERIC_ID_SMAC_MC,
+	DEVLINK_TRAP_GENERIC_ID_VLAN_TAG_MISMATCH,
+	DEVLINK_TRAP_GENERIC_ID_INGRESS_VLAN_FILTER,
+	DEVLINK_TRAP_GENERIC_ID_INGRESS_STP_FILTER,
+	DEVLINK_TRAP_GENERIC_ID_EMPTY_TX_LIST,
+	DEVLINK_TRAP_GENERIC_ID_EMPTY_TX_LIST,
+	DEVLINK_TRAP_GENERIC_ID_PORT_LOOPBACK_FILTER,
+};
+
+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)
+{
+	struct mlxsw_sp_port_pcpu_stats *pcpu_stats;
+
+	if (unlikely(!mlxsw_sp_port)) {
+		dev_warn_ratelimited(mlxsw_sp->bus_info->dev, "Port %d: skb received for non-existent port\n",
+				     local_port);
+		kfree_skb(skb);
+		return -EINVAL;
+	}
+
+	skb->dev = mlxsw_sp_port->dev;
+
+	pcpu_stats = this_cpu_ptr(mlxsw_sp_port->pcpu_stats);
+	u64_stats_update_begin(&pcpu_stats->syncp);
+	pcpu_stats->rx_packets++;
+	pcpu_stats->rx_bytes += skb->len;
+	u64_stats_update_end(&pcpu_stats->syncp);
+
+	skb->protocol = eth_type_trans(skb, skb->dev);
+
+	return 0;
+}
+
+static void mlxsw_sp_rx_drop_listener(struct sk_buff *skb, u8 local_port,
+				      void *trap_ctx)
+{
+	struct devlink_port *in_devlink_port;
+	struct mlxsw_sp_port *mlxsw_sp_port;
+	struct mlxsw_sp *mlxsw_sp;
+	struct devlink *devlink;
+
+	mlxsw_sp = devlink_trap_ctx_priv(trap_ctx);
+	mlxsw_sp_port = mlxsw_sp->ports[local_port];
+
+	if (mlxsw_sp_rx_listener(mlxsw_sp, skb, local_port, mlxsw_sp_port))
+		return;
+
+	devlink = priv_to_devlink(mlxsw_sp->core);
+	in_devlink_port = mlxsw_core_port_devlink_port_get(mlxsw_sp->core,
+							   local_port);
+	devlink_trap_report(devlink, skb, trap_ctx, in_devlink_port);
+	consume_skb(skb);
+}
+
+int mlxsw_sp_devlink_traps_init(struct mlxsw_sp *mlxsw_sp)
+{
+	struct devlink *devlink = priv_to_devlink(mlxsw_sp->core);
+
+	if (WARN_ON(ARRAY_SIZE(mlxsw_sp_listener_devlink_map) !=
+		    ARRAY_SIZE(mlxsw_sp_listeners_arr)))
+		return -EINVAL;
+
+	return devlink_traps_register(devlink, mlxsw_sp_traps_arr,
+				      ARRAY_SIZE(mlxsw_sp_traps_arr),
+				      mlxsw_sp);
+}
+
+void mlxsw_sp_devlink_traps_fini(struct mlxsw_sp *mlxsw_sp)
+{
+	struct devlink *devlink = priv_to_devlink(mlxsw_sp->core);
+
+	devlink_traps_unregister(devlink, mlxsw_sp_traps_arr,
+				 ARRAY_SIZE(mlxsw_sp_traps_arr));
+}
+
+int mlxsw_sp_trap_init(struct mlxsw_core *mlxsw_core,
+		       const struct devlink_trap *trap, void *trap_ctx)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(mlxsw_sp_listener_devlink_map); i++) {
+		struct mlxsw_listener *listener;
+		int err;
+
+		if (mlxsw_sp_listener_devlink_map[i] != trap->id)
+			continue;
+		listener = &mlxsw_sp_listeners_arr[i];
+
+		err = mlxsw_core_trap_register(mlxsw_core, listener, trap_ctx);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+void mlxsw_sp_trap_fini(struct mlxsw_core *mlxsw_core,
+			const struct devlink_trap *trap, void *trap_ctx)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(mlxsw_sp_listener_devlink_map); i++) {
+		struct mlxsw_listener *listener;
+
+		if (mlxsw_sp_listener_devlink_map[i] != trap->id)
+			continue;
+		listener = &mlxsw_sp_listeners_arr[i];
+
+		mlxsw_core_trap_unregister(mlxsw_core, listener, trap_ctx);
+	}
+}
+
+int mlxsw_sp_trap_action_set(struct mlxsw_core *mlxsw_core,
+			     const struct devlink_trap *trap,
+			     enum devlink_trap_action action)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(mlxsw_sp_listener_devlink_map); i++) {
+		enum mlxsw_reg_hpkt_action hw_action;
+		struct mlxsw_listener *listener;
+		int err;
+
+		if (mlxsw_sp_listener_devlink_map[i] != trap->id)
+			continue;
+		listener = &mlxsw_sp_listeners_arr[i];
+
+		switch (action) {
+		case DEVLINK_TRAP_ACTION_DROP:
+			hw_action = MLXSW_REG_HPKT_ACTION_SET_FW_DEFAULT;
+			break;
+		case DEVLINK_TRAP_ACTION_TRAP:
+			hw_action = MLXSW_REG_HPKT_ACTION_TRAP_EXCEPTION_TO_CPU;
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		err = mlxsw_core_trap_action_set(mlxsw_core, listener,
+						 hw_action);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+#define MLXSW_SP_DISCARD_POLICER_ID	(MLXSW_REG_HTGT_TRAP_GROUP_MAX + 1)
+
+static int
+mlxsw_sp_trap_group_policer_init(struct mlxsw_sp *mlxsw_sp,
+				 const struct devlink_trap_group *group)
+{
+	enum mlxsw_reg_qpcr_ir_units ir_units;
+	char qpcr_pl[MLXSW_REG_QPCR_LEN];
+	u16 policer_id;
+	u8 burst_size;
+	bool is_bytes;
+	u32 rate;
+
+	switch (group->id) {
+	case DEVLINK_TRAP_GROUP_GENERIC_ID_L2_DROPS:
+		policer_id = MLXSW_SP_DISCARD_POLICER_ID;
+		ir_units = MLXSW_REG_QPCR_IR_UNITS_M;
+		is_bytes = false;
+		rate = 10 * 1024; /* 10Kpps */
+		burst_size = 7;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	mlxsw_reg_qpcr_pack(qpcr_pl, policer_id, ir_units, is_bytes, rate,
+			    burst_size);
+	return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(qpcr), qpcr_pl);
+}
+
+static int
+__mlxsw_sp_trap_group_init(struct mlxsw_sp *mlxsw_sp,
+			   const struct devlink_trap_group *group)
+{
+	char htgt_pl[MLXSW_REG_HTGT_LEN];
+	u8 priority, tc, group_id;
+	u16 policer_id;
+
+	switch (group->id) {
+	case DEVLINK_TRAP_GROUP_GENERIC_ID_L2_DROPS:
+		group_id = MLXSW_REG_HTGT_TRAP_GROUP_SP_L2_DISCARDS;
+		policer_id = MLXSW_SP_DISCARD_POLICER_ID;
+		priority = 0;
+		tc = 1;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	mlxsw_reg_htgt_pack(htgt_pl, group_id, policer_id, priority, tc);
+	return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(htgt), htgt_pl);
+}
+
+int mlxsw_sp_trap_group_init(struct mlxsw_core *mlxsw_core,
+			     const struct devlink_trap_group *group)
+{
+	struct mlxsw_sp *mlxsw_sp = mlxsw_core_driver_priv(mlxsw_core);
+	int err;
+
+	err = mlxsw_sp_trap_group_policer_init(mlxsw_sp, group);
+	if (err)
+		return err;
+
+	err = __mlxsw_sp_trap_group_init(mlxsw_sp, group);
+	if (err)
+		return err;
+
+	return 0;
+}