net: marvell: prestera: handle fib notifications

For now we support only TRAP or DROP, so we can offload only "local" or
"blackhole" routes.
Nexthop routes is TRAP for now. Will be implemented soon.
Co-developed-by: Taras Chornyi <tchornyi@marvell.com>
Signed-off-by: Taras Chornyi <tchornyi@marvell.com>
Co-developed-by: Oleksandr Mazur <oleksandr.mazur@plvision.eu>
Signed-off-by: Oleksandr Mazur <oleksandr.mazur@plvision.eu>
Signed-off-by: Yevhen Orlov <yevhen.orlov@plvision.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/prestera/prestera.h

@@ -282,8 +282,10 @@ struct prestera_router {
 	struct list_head vr_list;
 	struct list_head rif_entry_list;
 	struct rhashtable fib_ht;
+	struct rhashtable kern_fib_cache_ht;
 	struct notifier_block inetaddr_nb;
 	struct notifier_block inetaddr_valid_nb;
+	struct notifier_block fib_nb;
 };
 
 struct prestera_rxtx_params {
@@ -326,6 +328,8 @@ int prestera_port_cfg_mac_write(struct prestera_port *port,
 
 struct prestera_port *prestera_port_dev_lower_find(struct net_device *dev);
 
+void prestera_queue_work(struct work_struct *work);
+
 int prestera_port_pvid_set(struct prestera_port *port, u16 vid);
 
 bool prestera_netdev_check(const struct net_device *dev);

drivers/net/ethernet/marvell/prestera/prestera_main.c

@@ -28,6 +28,12 @@
 #define PRESTERA_MAC_ADDR_NUM_MAX	255
 
 static struct workqueue_struct *prestera_wq;
+static struct workqueue_struct *prestera_owq;
+
+void prestera_queue_work(struct work_struct *work)
+{
+	queue_work(prestera_owq, work);
+}
 
 int prestera_port_pvid_set(struct prestera_port *port, u16 vid)
 {
@@ -1024,12 +1030,17 @@ static int __init prestera_module_init(void)
 	if (!prestera_wq)
 		return -ENOMEM;
 
+	prestera_owq = alloc_ordered_workqueue("prestera_ordered", 0);
+	if (!prestera_owq)
+		return -ENOMEM;
+
 	return 0;
 }
 
 static void __exit prestera_module_exit(void)
 {
 	destroy_workqueue(prestera_wq);
+	destroy_workqueue(prestera_owq);
 }
 
 module_init(prestera_module_init);

drivers/net/ethernet/marvell/prestera/prestera_router.c

@@ -5,10 +5,39 @@
 #include <linux/types.h>
 #include <linux/inetdevice.h>
 #include <net/switchdev.h>
+#include <linux/rhashtable.h>
 
 #include "prestera.h"
 #include "prestera_router_hw.h"
 
+struct prestera_kern_fib_cache_key {
+	struct prestera_ip_addr addr;
+	u32 prefix_len;
+	u32 kern_tb_id; /* tb_id from kernel (not fixed) */
+};
+
+/* Subscribing on neighbours in kernel */
+struct prestera_kern_fib_cache {
+	struct prestera_kern_fib_cache_key key;
+	struct {
+		struct prestera_fib_key fib_key;
+		enum prestera_fib_type fib_type;
+	} lpm_info; /* hold prepared lpm info */
+	/* Indicate if route is not overlapped by another table */
+	struct rhash_head ht_node; /* node of prestera_router */
+	struct fib_info *fi;
+	u8 kern_tos;
+	u8 kern_type;
+	bool reachable;
+};
+
+static const struct rhashtable_params __prestera_kern_fib_cache_ht_params = {
+	.key_offset  = offsetof(struct prestera_kern_fib_cache, key),
+	.head_offset = offsetof(struct prestera_kern_fib_cache, ht_node),
+	.key_len     = sizeof(struct prestera_kern_fib_cache_key),
+	.automatic_shrinking = true,
+};
+
 /* This util to be used, to convert kernel rules for default vr in hw_vr */
 static u32 prestera_fix_tb_id(u32 tb_id)
 {
@@ -20,6 +49,290 @@ static u32 prestera_fix_tb_id(u32 tb_id)
 	return tb_id;
 }
 
+static void
+prestera_util_fen_info2fib_cache_key(struct fib_entry_notifier_info *fen_info,
+				     struct prestera_kern_fib_cache_key *key)
+{
+	memset(key, 0, sizeof(*key));
+	key->addr.u.ipv4 = cpu_to_be32(fen_info->dst);
+	key->prefix_len = fen_info->dst_len;
+	key->kern_tb_id = fen_info->tb_id;
+}
+
+static struct prestera_kern_fib_cache *
+prestera_kern_fib_cache_find(struct prestera_switch *sw,
+			     struct prestera_kern_fib_cache_key *key)
+{
+	struct prestera_kern_fib_cache *fib_cache;
+
+	fib_cache =
+	 rhashtable_lookup_fast(&sw->router->kern_fib_cache_ht, key,
+				__prestera_kern_fib_cache_ht_params);
+	return IS_ERR(fib_cache) ? NULL : fib_cache;
+}
+
+static void
+prestera_kern_fib_cache_destroy(struct prestera_switch *sw,
+				struct prestera_kern_fib_cache *fib_cache)
+{
+	fib_info_put(fib_cache->fi);
+	rhashtable_remove_fast(&sw->router->kern_fib_cache_ht,
+			       &fib_cache->ht_node,
+			       __prestera_kern_fib_cache_ht_params);
+	kfree(fib_cache);
+}
+
+/* Operations on fi (offload, etc) must be wrapped in utils.
+ * This function just create storage.
+ */
+static struct prestera_kern_fib_cache *
+prestera_kern_fib_cache_create(struct prestera_switch *sw,
+			       struct prestera_kern_fib_cache_key *key,
+			       struct fib_info *fi, u8 tos, u8 type)
+{
+	struct prestera_kern_fib_cache *fib_cache;
+	int err;
+
+	fib_cache = kzalloc(sizeof(*fib_cache), GFP_KERNEL);
+	if (!fib_cache)
+		goto err_kzalloc;
+
+	memcpy(&fib_cache->key, key, sizeof(*key));
+	fib_info_hold(fi);
+	fib_cache->fi = fi;
+	fib_cache->kern_tos = tos;
+	fib_cache->kern_type = type;
+
+	err = rhashtable_insert_fast(&sw->router->kern_fib_cache_ht,
+				     &fib_cache->ht_node,
+				     __prestera_kern_fib_cache_ht_params);
+	if (err)
+		goto err_ht_insert;
+
+	return fib_cache;
+
+err_ht_insert:
+	fib_info_put(fi);
+	kfree(fib_cache);
+err_kzalloc:
+	return NULL;
+}
+
+static void
+__prestera_k_arb_fib_lpm_offload_set(struct prestera_switch *sw,
+				     struct prestera_kern_fib_cache *fc,
+				     bool fail, bool offload, bool trap)
+{
+	struct fib_rt_info fri;
+
+	if (fc->key.addr.v != PRESTERA_IPV4)
+		return;
+
+	fri.fi = fc->fi;
+	fri.tb_id = fc->key.kern_tb_id;
+	fri.dst = fc->key.addr.u.ipv4;
+	fri.dst_len = fc->key.prefix_len;
+	fri.tos = fc->kern_tos;
+	fri.type = fc->kern_type;
+	/* flags begin */
+	fri.offload = offload;
+	fri.trap = trap;
+	fri.offload_failed = fail;
+	/* flags end */
+	fib_alias_hw_flags_set(&init_net, &fri);
+}
+
+static int
+__prestera_pr_k_arb_fc_lpm_info_calc(struct prestera_switch *sw,
+				     struct prestera_kern_fib_cache *fc)
+{
+	memset(&fc->lpm_info, 0, sizeof(fc->lpm_info));
+
+	switch (fc->fi->fib_type) {
+	case RTN_UNICAST:
+		fc->lpm_info.fib_type = PRESTERA_FIB_TYPE_TRAP;
+		break;
+	/* Unsupported. Leave it for kernel: */
+	case RTN_BROADCAST:
+	case RTN_MULTICAST:
+	/* Routes we must trap by design: */
+	case RTN_LOCAL:
+	case RTN_UNREACHABLE:
+	case RTN_PROHIBIT:
+		fc->lpm_info.fib_type = PRESTERA_FIB_TYPE_TRAP;
+		break;
+	case RTN_BLACKHOLE:
+		fc->lpm_info.fib_type = PRESTERA_FIB_TYPE_DROP;
+		break;
+	default:
+		dev_err(sw->dev->dev, "Unsupported fib_type");
+		return -EOPNOTSUPP;
+	}
+
+	fc->lpm_info.fib_key.addr = fc->key.addr;
+	fc->lpm_info.fib_key.prefix_len = fc->key.prefix_len;
+	fc->lpm_info.fib_key.tb_id = prestera_fix_tb_id(fc->key.kern_tb_id);
+
+	return 0;
+}
+
+static int __prestera_k_arb_f_lpm_set(struct prestera_switch *sw,
+				      struct prestera_kern_fib_cache *fc,
+				      bool enabled)
+{
+	struct prestera_fib_node *fib_node;
+
+	fib_node = prestera_fib_node_find(sw, &fc->lpm_info.fib_key);
+	if (fib_node)
+		prestera_fib_node_destroy(sw, fib_node);
+
+	if (!enabled)
+		return 0;
+
+	fib_node = prestera_fib_node_create(sw, &fc->lpm_info.fib_key,
+					    fc->lpm_info.fib_type);
+
+	if (!fib_node) {
+		dev_err(sw->dev->dev, "fib_node=NULL %pI4n/%d kern_tb_id = %d",
+			&fc->key.addr.u.ipv4, fc->key.prefix_len,
+			fc->key.kern_tb_id);
+		return -ENOENT;
+	}
+
+	return 0;
+}
+
+static int __prestera_k_arb_fc_apply(struct prestera_switch *sw,
+				     struct prestera_kern_fib_cache *fc)
+{
+	int err;
+
+	err = __prestera_pr_k_arb_fc_lpm_info_calc(sw, fc);
+	if (err)
+		return err;
+
+	err = __prestera_k_arb_f_lpm_set(sw, fc, fc->reachable);
+	if (err) {
+		__prestera_k_arb_fib_lpm_offload_set(sw, fc,
+						     true, false, false);
+		return err;
+	}
+
+	switch (fc->lpm_info.fib_type) {
+	case PRESTERA_FIB_TYPE_TRAP:
+		__prestera_k_arb_fib_lpm_offload_set(sw, fc, false,
+						     false, fc->reachable);
+		break;
+	case PRESTERA_FIB_TYPE_DROP:
+		__prestera_k_arb_fib_lpm_offload_set(sw, fc, false, true,
+						     fc->reachable);
+		break;
+	case PRESTERA_FIB_TYPE_INVALID:
+		break;
+	}
+
+	return 0;
+}
+
+static struct prestera_kern_fib_cache *
+__prestera_k_arb_util_fib_overlaps(struct prestera_switch *sw,
+				   struct prestera_kern_fib_cache *fc)
+{
+	struct prestera_kern_fib_cache_key fc_key;
+	struct prestera_kern_fib_cache *rfc;
+
+	/* TODO: parse kernel rules */
+	rfc = NULL;
+	if (fc->key.kern_tb_id == RT_TABLE_LOCAL) {
+		memcpy(&fc_key, &fc->key, sizeof(fc_key));
+		fc_key.kern_tb_id = RT_TABLE_MAIN;
+		rfc = prestera_kern_fib_cache_find(sw, &fc_key);
+	}
+
+	return rfc;
+}
+
+static struct prestera_kern_fib_cache *
+__prestera_k_arb_util_fib_overlapped(struct prestera_switch *sw,
+				     struct prestera_kern_fib_cache *fc)
+{
+	struct prestera_kern_fib_cache_key fc_key;
+	struct prestera_kern_fib_cache *rfc;
+
+	/* TODO: parse kernel rules */
+	rfc = NULL;
+	if (fc->key.kern_tb_id == RT_TABLE_MAIN) {
+		memcpy(&fc_key, &fc->key, sizeof(fc_key));
+		fc_key.kern_tb_id = RT_TABLE_LOCAL;
+		rfc = prestera_kern_fib_cache_find(sw, &fc_key);
+	}
+
+	return rfc;
+}
+
+static int
+prestera_k_arb_fib_evt(struct prestera_switch *sw,
+		       bool replace, /* replace or del */
+		       struct fib_entry_notifier_info *fen_info)
+{
+	struct prestera_kern_fib_cache *tfib_cache, *bfib_cache; /* top/btm */
+	struct prestera_kern_fib_cache_key fc_key;
+	struct prestera_kern_fib_cache *fib_cache;
+	int err;
+
+	prestera_util_fen_info2fib_cache_key(fen_info, &fc_key);
+	fib_cache = prestera_kern_fib_cache_find(sw, &fc_key);
+	if (fib_cache) {
+		fib_cache->reachable = false;
+		err = __prestera_k_arb_fc_apply(sw, fib_cache);
+		if (err)
+			dev_err(sw->dev->dev,
+				"Applying destroyed fib_cache failed");
+
+		bfib_cache = __prestera_k_arb_util_fib_overlaps(sw, fib_cache);
+		tfib_cache = __prestera_k_arb_util_fib_overlapped(sw, fib_cache);
+		if (!tfib_cache && bfib_cache) {
+			bfib_cache->reachable = true;
+			err = __prestera_k_arb_fc_apply(sw, bfib_cache);
+			if (err)
+				dev_err(sw->dev->dev,
+					"Applying fib_cache btm failed");
+		}
+
+		prestera_kern_fib_cache_destroy(sw, fib_cache);
+	}
+
+	if (replace) {
+		fib_cache = prestera_kern_fib_cache_create(sw, &fc_key,
+							   fen_info->fi,
+							   fen_info->tos,
+							   fen_info->type);
+		if (!fib_cache) {
+			dev_err(sw->dev->dev, "fib_cache == NULL");
+			return -ENOENT;
+		}
+
+		bfib_cache = __prestera_k_arb_util_fib_overlaps(sw, fib_cache);
+		tfib_cache = __prestera_k_arb_util_fib_overlapped(sw, fib_cache);
+		if (!tfib_cache)
+			fib_cache->reachable = true;
+
+		if (bfib_cache) {
+			bfib_cache->reachable = false;
+			err = __prestera_k_arb_fc_apply(sw, bfib_cache);
+			if (err)
+				dev_err(sw->dev->dev,
+					"Applying fib_cache btm failed");
+		}
+
+		err = __prestera_k_arb_fc_apply(sw, fib_cache);
+		if (err)
+			dev_err(sw->dev->dev, "Applying fib_cache failed");
+	}
+
+	return 0;
+}
+
 static int __prestera_inetaddr_port_event(struct net_device *port_dev,
 					  unsigned long event,
 					  struct netlink_ext_ack *extack)
@@ -137,6 +450,89 @@ static int __prestera_inetaddr_valid_cb(struct notifier_block *nb,
 	return notifier_from_errno(err);
 }
 
+struct prestera_fib_event_work {
+	struct work_struct work;
+	struct prestera_switch *sw;
+	struct fib_entry_notifier_info fen_info;
+	unsigned long event;
+};
+
+static void __prestera_router_fib_event_work(struct work_struct *work)
+{
+	struct prestera_fib_event_work *fib_work =
+			container_of(work, struct prestera_fib_event_work, work);
+	struct prestera_switch *sw = fib_work->sw;
+	int err;
+
+	rtnl_lock();
+
+	switch (fib_work->event) {
+	case FIB_EVENT_ENTRY_REPLACE:
+		err = prestera_k_arb_fib_evt(sw, true, &fib_work->fen_info);
+		if (err)
+			goto err_out;
+
+		break;
+	case FIB_EVENT_ENTRY_DEL:
+		err = prestera_k_arb_fib_evt(sw, false, &fib_work->fen_info);
+		if (err)
+			goto err_out;
+
+		break;
+	}
+
+	goto out;
+
+err_out:
+	dev_err(sw->dev->dev, "Error when processing %pI4h/%d",
+		&fib_work->fen_info.dst,
+		fib_work->fen_info.dst_len);
+out:
+	fib_info_put(fib_work->fen_info.fi);
+	rtnl_unlock();
+	kfree(fib_work);
+}
+
+/* Called with rcu_read_lock() */
+static int __prestera_router_fib_event(struct notifier_block *nb,
+				       unsigned long event, void *ptr)
+{
+	struct prestera_fib_event_work *fib_work;
+	struct fib_entry_notifier_info *fen_info;
+	struct fib_notifier_info *info = ptr;
+	struct prestera_router *router;
+
+	if (info->family != AF_INET)
+		return NOTIFY_DONE;
+
+	router = container_of(nb, struct prestera_router, fib_nb);
+
+	switch (event) {
+	case FIB_EVENT_ENTRY_REPLACE:
+	case FIB_EVENT_ENTRY_DEL:
+		fen_info = container_of(info, struct fib_entry_notifier_info,
+					info);
+		if (!fen_info->fi)
+			return NOTIFY_DONE;
+
+		fib_work = kzalloc(sizeof(*fib_work), GFP_ATOMIC);
+		if (WARN_ON(!fib_work))
+			return NOTIFY_BAD;
+
+		fib_info_hold(fen_info->fi);
+		fib_work->fen_info = *fen_info;
+		fib_work->event = event;
+		fib_work->sw = router->sw;
+		INIT_WORK(&fib_work->work, __prestera_router_fib_event_work);
+		prestera_queue_work(&fib_work->work);
+		break;
+	default:
+		return NOTIFY_DONE;
+	}
+
+	return NOTIFY_DONE;
+}
+
 int prestera_router_init(struct prestera_switch *sw)
 {
 	struct prestera_router *router;
@@ -153,6 +549,11 @@ int prestera_router_init(struct prestera_switch *sw)
 	if (err)
 		goto err_router_lib_init;
 
+	err = rhashtable_init(&router->kern_fib_cache_ht,
+			      &__prestera_kern_fib_cache_ht_params);
+	if (err)
+		goto err_kern_fib_cache_ht_init;
+
 	router->inetaddr_valid_nb.notifier_call = __prestera_inetaddr_valid_cb;
 	err = register_inetaddr_validator_notifier(&router->inetaddr_valid_nb);
 	if (err)
@@ -163,11 +564,21 @@ int prestera_router_init(struct prestera_switch *sw)
 	if (err)
 		goto err_register_inetaddr_notifier;
 
+	router->fib_nb.notifier_call = __prestera_router_fib_event;
+	err = register_fib_notifier(&init_net, &router->fib_nb,
+				    /* TODO: flush fib entries */ NULL, NULL);
+	if (err)
+		goto err_register_fib_notifier;
+
 	return 0;
 
+err_register_fib_notifier:
+	unregister_inetaddr_notifier(&router->inetaddr_nb);
 err_register_inetaddr_notifier:
 	unregister_inetaddr_validator_notifier(&router->inetaddr_valid_nb);
 err_register_inetaddr_validator_notifier:
+	rhashtable_destroy(&router->kern_fib_cache_ht);
+err_kern_fib_cache_ht_init:
 	prestera_router_hw_fini(sw);
 err_router_lib_init:
 	kfree(sw->router);
@@ -178,6 +589,7 @@ void prestera_router_fini(struct prestera_switch *sw)
 {
 	unregister_inetaddr_notifier(&sw->router->inetaddr_nb);
 	unregister_inetaddr_validator_notifier(&sw->router->inetaddr_valid_nb);
+	rhashtable_destroy(&sw->router->kern_fib_cache_ht);
 	prestera_router_hw_fini(sw);
 	kfree(sw->router);
 	sw->router = NULL;