[PATCH net-next v2 2/3] net: ethernet: ti: am65-cpsw: enable bc/mc storm prevention support

Grygorii Strashko
2021-11-01T17:02:00Z

This patch enables support for ingress broadcast(BC)/multicast(MC) packets
rate limiting in TI AM65x CPSW driver (the corresponding ALE support was
added in previous patch) by implementing HW offload for simple tc-flower
with policer action with matches on dst_mac:
- ff:ff:ff:ff:ff:ff has to be used for BC packets rate limiting (exact
match)
- 01:00:00:00:00:00 fixed value has to be used for MC packets rate
limiting (exact match)

The CPSW supports MC/BC packets rate limiting in packets/sec and affects
all ingress MC/BC packets and serves as BC/MC storm prevention feature.

Examples:
- BC rate limit to 1000pps:
tc qdisc add dev eth0 clsact
tc filter add dev eth0 ingress flower skip_sw dst_mac ff:ff:ff:ff:ff:ff \
action police pkts_rate 1000 pkts_burst 1

- MC rate limit to 20000pps:
tc qdisc add dev eth0 clsact
tc filter add dev eth0 ingress flower skip_sw dst_mac 01:00:00:00:00:00 \
action police pkts_rate 10000 pkts_burst 1

pkts_burst - not used.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
---
drivers/net/ethernet/ti/am65-cpsw-qos.c | 145 ++++++++++++++++++++++++
drivers/net/ethernet/ti/am65-cpsw-qos.h | 8 ++
2 files changed, 153 insertions(+)

diff --git a/drivers/net/ethernet/ti/am65-cpsw-qos.c b/drivers/net/ethernet/ti/am65-cpsw-qos.c
index ebcc6386cc34..41f0cf56eeb8 100644
--- a/drivers/net/ethernet/ti/am65-cpsw-qos.c
+++ b/drivers/net/ethernet/ti/am65-cpsw-qos.c
@@ -8,10 +8,12 @@

#include <linux/pm_runtime.h>
#include <linux/time.h>
+#include <net/pkt_cls.h>

#include "am65-cpsw-nuss.h"
#include "am65-cpsw-qos.h"
#include "am65-cpts.h"
+#include "cpsw_ale.h"

#define AM65_CPSW_REG_CTL 0x004
#define AM65_CPSW_PN_REG_CTL 0x004
@@ -588,12 +590,155 @@ static int am65_cpsw_setup_taprio(struct net_device *ndev, void *type_data)
return am65_cpsw_set_taprio(ndev, type_data);
}

+static int am65_cpsw_qos_clsflower_add_policer(struct am65_cpsw_port *port,
+ struct netlink_ext_ack *extack,
+ struct flow_cls_offload *cls,
+ u64 rate_pkt_ps)
+{
+ struct flow_rule *rule = flow_cls_offload_flow_rule(cls);
+ struct flow_dissector *dissector = rule->match.dissector;
+ u8 mc_mac[] = {0x01, 0x00, 0x00, 0x00, 0x00, 0x00};
+ struct am65_cpsw_qos *qos = &port->qos;
+ struct flow_match_eth_addrs match;
+ int ret;
+
+ if (dissector->used_keys &
+ ~(BIT(FLOW_DISSECTOR_KEY_BASIC) |
+ BIT(FLOW_DISSECTOR_KEY_CONTROL) |
+ BIT(FLOW_DISSECTOR_KEY_ETH_ADDRS))) {
+ NL_SET_ERR_MSG_MOD(extack,
+ "Unsupported keys used");
+ return -EOPNOTSUPP;
+ }
+
+ if (!flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
+ NL_SET_ERR_MSG_MOD(extack, "Not matching on eth address");
+ return -EOPNOTSUPP;
+ }
+
+ flow_rule_match_eth_addrs(rule, &match);
+
+ if (!is_zero_ether_addr(match.key->src)) {
+ NL_SET_ERR_MSG_MOD(extack,
+ "Matching on source MAC not supported");
+ return -EOPNOTSUPP;
+ }
+
+ if (is_broadcast_ether_addr(match.key->dst)) {
+ ret = cpsw_ale_rx_ratelimit_bc(port->common->ale, port->port_id, rate_pkt_ps);
+ if (ret)
+ return ret;
+
+ qos->ale_bc_ratelimit.cookie = cls->cookie;
+ qos->ale_bc_ratelimit.rate_packet_ps = rate_pkt_ps;
+ }
+
+ if (ether_addr_equal(match.key->dst, mc_mac)) {
+ ret = cpsw_ale_rx_ratelimit_mc(port->common->ale, port->port_id, rate_pkt_ps);
+ if (ret)
+ return ret;
+
+ qos->ale_mc_ratelimit.cookie = cls->cookie;
+ qos->ale_mc_ratelimit.rate_packet_ps = rate_pkt_ps;
+ }
+
+ return 0;
+}
+
+static int am65_cpsw_qos_configure_clsflower(struct am65_cpsw_port *port,
+ struct flow_cls_offload *cls)
+{
+ struct flow_rule *rule = flow_cls_offload_flow_rule(cls);
+ struct netlink_ext_ack *extack = cls->common.extack;
+ const struct flow_action_entry *act;
+ int i;
+
+ flow_action_for_each(i, act, &rule->action) {
+ switch (act->id) {
+ case FLOW_ACTION_POLICE:
+ if (act->police.rate_bytes_ps) {
+ NL_SET_ERR_MSG_MOD(extack,
+ "QoS offload not support bytes per second");
+ return -EOPNOTSUPP;
+ }
+
+ return am65_cpsw_qos_clsflower_add_policer(port, extack, cls,
+ act->police.rate_pkt_ps);
+ default:
+ NL_SET_ERR_MSG_MOD(extack,
+ "Action not supported");
+ return -EOPNOTSUPP;
+ }
+ }
+ return -EOPNOTSUPP;
+}
+
+static int am65_cpsw_qos_delete_clsflower(struct am65_cpsw_port *port, struct flow_cls_offload *cls)
+{
+ struct am65_cpsw_qos *qos = &port->qos;
+
+ if (cls->cookie == qos->ale_bc_ratelimit.cookie) {
+ qos->ale_bc_ratelimit.cookie = 0;
+ qos->ale_bc_ratelimit.rate_packet_ps = 0;
+ cpsw_ale_rx_ratelimit_bc(port->common->ale, port->port_id, 0);
+ }
+
+ if (cls->cookie == qos->ale_mc_ratelimit.cookie) {
+ qos->ale_mc_ratelimit.cookie = 0;
+ qos->ale_mc_ratelimit.rate_packet_ps = 0;
+ cpsw_ale_rx_ratelimit_mc(port->common->ale, port->port_id, 0);
+ }
+
+ return 0;
+}
+
+static int am65_cpsw_qos_setup_tc_clsflower(struct am65_cpsw_port *port,
+ struct flow_cls_offload *cls_flower)
+{
+ switch (cls_flower->command) {
+ case FLOW_CLS_REPLACE:
+ return am65_cpsw_qos_configure_clsflower(port, cls_flower);
+ case FLOW_CLS_DESTROY:
+ return am65_cpsw_qos_delete_clsflower(port, cls_flower);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static int am65_cpsw_qos_setup_tc_block_cb(enum tc_setup_type type, void *type_data, void *cb_priv)
+{
+ struct am65_cpsw_port *port = cb_priv;
+
+ if (!tc_cls_can_offload_and_chain0(port->ndev, type_data))
+ return -EOPNOTSUPP;
+
+ switch (type) {
+ case TC_SETUP_CLSFLOWER:
+ return am65_cpsw_qos_setup_tc_clsflower(port, type_data);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static LIST_HEAD(am65_cpsw_qos_block_cb_list);
+
+static int am65_cpsw_qos_setup_tc_block(struct net_device *ndev, struct flow_block_offload *f)
+{
+ struct am65_cpsw_port *port = am65_ndev_to_port(ndev);
+
+ return flow_block_cb_setup_simple(f, &am65_cpsw_qos_block_cb_list,
+ am65_cpsw_qos_setup_tc_block_cb,
+ port, port, true);
+}
+
int am65_cpsw_qos_ndo_setup_tc(struct net_device *ndev, enum tc_setup_type type,
void *type_data)
{
switch (type) {
case TC_SETUP_QDISC_TAPRIO:
return am65_cpsw_setup_taprio(ndev, type_data);
+ case TC_SETUP_BLOCK:
+ return am65_cpsw_qos_setup_tc_block(ndev, type_data);
default:
return -EOPNOTSUPP;
}
diff --git a/drivers/net/ethernet/ti/am65-cpsw-qos.h b/drivers/net/ethernet/ti/am65-cpsw-qos.h
index e8f1b6b59e93..fb223b43b196 100644
--- a/drivers/net/ethernet/ti/am65-cpsw-qos.h
+++ b/drivers/net/ethernet/ti/am65-cpsw-qos.h
@@ -14,11 +14,19 @@ struct am65_cpsw_est {
struct tc_taprio_qopt_offload taprio;
};

+struct am65_cpsw_ale_ratelimit {
+ unsigned long cookie;
+ u64 rate_packet_ps;
+};
+
struct am65_cpsw_qos {
struct am65_cpsw_est *est_admin;
struct am65_cpsw_est *est_oper;
ktime_t link_down_time;
int link_speed;
+
+ struct am65_cpsw_ale_ratelimit ale_bc_ratelimit;
+ struct am65_cpsw_ale_ratelimit ale_mc_ratelimit;
};

int am65_cpsw_qos_ndo_setup_tc(struct net_device *ndev, enum tc_setup_type type,
--
2.17.1