[PATCH net-next v4 9/9] net: marvell: prestera: Propogate nh state from hw to kernel

From: Yevhen Orlov
Date: Thu Aug 25 2022 - 16:25:58 EST


We poll nexthops in HW and call for each active nexthop appropriate
neighbour.

Also we provide implicity neighbour resolving.
For example, user have added nexthop route:
# ip route add 5.5.5.5 via 1.1.1.2
But neighbour 1.1.1.2 doesn't exist. In this case we will try to call
neigh_event_send, even if there is no traffic.
This is usefull, when you have add route, which will be used after some
time but with a lot of traffic (burst). So, we has prepared, offloaded
route in advance.

Co-developed-by: Taras Chornyi <tchornyi@xxxxxxxxxxx>
Signed-off-by: Taras Chornyi <tchornyi@xxxxxxxxxxx>
Co-developed-by: Oleksandr Mazur <oleksandr.mazur@xxxxxxxxxxx>
Signed-off-by: Oleksandr Mazur <oleksandr.mazur@xxxxxxxxxxx>
Signed-off-by: Yevhen Orlov <yevhen.orlov@xxxxxxxxxxx>
---
.../net/ethernet/marvell/prestera/prestera.h | 3 +
.../marvell/prestera/prestera_router.c | 111 ++++++++++++++++++
2 files changed, 114 insertions(+)

diff --git a/drivers/net/ethernet/marvell/prestera/prestera.h b/drivers/net/ethernet/marvell/prestera/prestera.h
index 4d24e0e216dc..055761463088 100644
--- a/drivers/net/ethernet/marvell/prestera/prestera.h
+++ b/drivers/net/ethernet/marvell/prestera/prestera.h
@@ -324,6 +324,9 @@ struct prestera_router {
struct notifier_block netevent_nb;
u8 *nhgrp_hw_state_cache; /* Bitmap cached hw state of nhs */
unsigned long nhgrp_hw_cache_kick; /* jiffies */
+ struct {
+ struct delayed_work dw;
+ } neighs_update;
};

struct prestera_rxtx_params {
diff --git a/drivers/net/ethernet/marvell/prestera/prestera_router.c b/drivers/net/ethernet/marvell/prestera/prestera_router.c
index 5d6dd8a9f176..9b612b725a16 100644
--- a/drivers/net/ethernet/marvell/prestera/prestera_router.c
+++ b/drivers/net/ethernet/marvell/prestera/prestera_router.c
@@ -16,6 +16,9 @@
#include "prestera.h"
#include "prestera_router_hw.h"

+#define PRESTERA_IMPLICITY_RESOLVE_DEAD_NEIGH
+#define PRESTERA_NH_PROBE_INTERVAL 5000 /* ms */
+
struct prestera_kern_neigh_cache_key {
struct prestera_ip_addr addr;
struct net_device *dev;
@@ -32,6 +35,7 @@ struct prestera_kern_neigh_cache {
/* Indicate if neighbour is reachable by direct route */
bool reachable;
};
+
struct prestera_kern_fib_cache_key {
struct prestera_ip_addr addr;
u32 prefix_len;
@@ -1016,6 +1020,78 @@ __prestera_k_arb_util_fib_overlapped(struct prestera_switch *sw,
return rfc;
}

+static void __prestera_k_arb_hw_state_upd(struct prestera_switch *sw,
+ struct prestera_kern_neigh_cache *nc)
+{
+ struct prestera_nh_neigh_key nh_key;
+ struct prestera_nh_neigh *nh_neigh;
+ struct neighbour *n;
+ bool hw_active;
+
+ prestera_util_nc_key2nh_key(&nc->key, &nh_key);
+ nh_neigh = prestera_nh_neigh_find(sw, &nh_key);
+ if (!nh_neigh) {
+ pr_err("Cannot find nh_neigh for cached %pI4n",
+ &nc->key.addr.u.ipv4);
+ return;
+ }
+
+ hw_active = prestera_nh_neigh_util_hw_state(sw, nh_neigh);
+
+#ifdef PRESTERA_IMPLICITY_RESOLVE_DEAD_NEIGH
+ if (!hw_active && nc->in_kernel)
+ goto out;
+#else /* PRESTERA_IMPLICITY_RESOLVE_DEAD_NEIGH */
+ if (!hw_active)
+ goto out;
+#endif /* PRESTERA_IMPLICITY_RESOLVE_DEAD_NEIGH */
+
+ if (nc->key.addr.v == PRESTERA_IPV4) {
+ n = neigh_lookup(&arp_tbl, &nc->key.addr.u.ipv4,
+ nc->key.dev);
+ if (!n)
+ n = neigh_create(&arp_tbl, &nc->key.addr.u.ipv4,
+ nc->key.dev);
+ } else {
+ n = NULL;
+ }
+
+ if (!IS_ERR(n) && n) {
+ neigh_event_send(n, NULL);
+ neigh_release(n);
+ } else {
+ pr_err("Cannot create neighbour %pI4n", &nc->key.addr.u.ipv4);
+ }
+
+out:
+ return;
+}
+
+/* Propagate hw state to kernel */
+static void prestera_k_arb_hw_evt(struct prestera_switch *sw)
+{
+ struct prestera_kern_neigh_cache *n_cache;
+ struct rhashtable_iter iter;
+
+ rhashtable_walk_enter(&sw->router->kern_neigh_cache_ht, &iter);
+ rhashtable_walk_start(&iter);
+ while (1) {
+ n_cache = rhashtable_walk_next(&iter);
+
+ if (!n_cache)
+ break;
+
+ if (IS_ERR(n_cache))
+ continue;
+
+ rhashtable_walk_stop(&iter);
+ __prestera_k_arb_hw_state_upd(sw, n_cache);
+ rhashtable_walk_start(&iter);
+ }
+ rhashtable_walk_stop(&iter);
+ rhashtable_walk_exit(&iter);
+}
+
/* Propagate kernel event to hw */
static void prestera_k_arb_n_evt(struct prestera_switch *sw,
struct neighbour *n)
@@ -1462,6 +1538,34 @@ static int prestera_router_netevent_event(struct notifier_block *nb,
return NOTIFY_DONE;
}

+static void prestera_router_update_neighs_work(struct work_struct *work)
+{
+ struct prestera_router *router;
+
+ router = container_of(work, struct prestera_router,
+ neighs_update.dw.work);
+ rtnl_lock();
+
+ prestera_k_arb_hw_evt(router->sw);
+
+ rtnl_unlock();
+ prestera_queue_delayed_work(&router->neighs_update.dw,
+ msecs_to_jiffies(PRESTERA_NH_PROBE_INTERVAL));
+}
+
+static int prestera_neigh_work_init(struct prestera_switch *sw)
+{
+ INIT_DELAYED_WORK(&sw->router->neighs_update.dw,
+ prestera_router_update_neighs_work);
+ prestera_queue_delayed_work(&sw->router->neighs_update.dw, 0);
+ return 0;
+}
+
+static void prestera_neigh_work_fini(struct prestera_switch *sw)
+{
+ cancel_delayed_work_sync(&sw->router->neighs_update.dw);
+}
+
int prestera_router_init(struct prestera_switch *sw)
{
struct prestera_router *router;
@@ -1495,6 +1599,10 @@ int prestera_router_init(struct prestera_switch *sw)
goto err_nh_state_cache_alloc;
}

+ err = prestera_neigh_work_init(sw);
+ if (err)
+ goto err_neigh_work_init;
+
router->inetaddr_valid_nb.notifier_call = __prestera_inetaddr_valid_cb;
err = register_inetaddr_validator_notifier(&router->inetaddr_valid_nb);
if (err)
@@ -1525,6 +1633,8 @@ int prestera_router_init(struct prestera_switch *sw)
err_register_inetaddr_notifier:
unregister_inetaddr_validator_notifier(&router->inetaddr_valid_nb);
err_register_inetaddr_validator_notifier:
+ prestera_neigh_work_fini(sw);
+err_neigh_work_init:
kfree(router->nhgrp_hw_state_cache);
err_nh_state_cache_alloc:
rhashtable_destroy(&router->kern_neigh_cache_ht);
@@ -1543,6 +1653,7 @@ void prestera_router_fini(struct prestera_switch *sw)
unregister_netevent_notifier(&sw->router->netevent_nb);
unregister_inetaddr_notifier(&sw->router->inetaddr_nb);
unregister_inetaddr_validator_notifier(&sw->router->inetaddr_valid_nb);
+ prestera_neigh_work_fini(sw);
prestera_queue_drain();

prestera_k_arb_abort(sw);
--
2.17.1