Commit 20d3c1e9 authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by Jakub Kicinski
Browse files

hsr: Use a single struct for self_node. 



self_node_db is a list_head with one entry of struct hsr_node. The
purpose is to hold the two MAC addresses of the node itself.
It is convenient to recycle the structure. However having a list_head
and fetching always the first entry is not really optimal.

Created a new data strucure contaning the two MAC addresses named
hsr_self_node. Access that structure like an RCU protected pointer so
it can be replaced on the fly without blocking the reader.

Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: default avatarKurt Kanzenbach <kurt@linutronix.de>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 5c7aa132

net/hsr/hsr_device.c

+0 −1
Original line number Diff line number Diff line
@@ -490,7 +490,6 @@ int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2], 
	hsr = netdev_priv(hsr_dev);

	INIT_LIST_HEAD(&hsr->ports);

	INIT_LIST_HEAD(&hsr->node_db);

	INIT_LIST_HEAD(&hsr->self_node_db);

	spin_lock_init(&hsr->list_lock);



	eth_hw_addr_set(hsr_dev, slave[0]->dev_addr);

net/hsr/hsr_framereg.c

+28 −35
Original line number Diff line number Diff line
@@ -38,21 +38,22 @@ static bool seq_nr_after(u16 a, u16 b) 


bool hsr_addr_is_self(struct hsr_priv *hsr, unsigned char *addr)

{

	struct hsr_node *node;

	struct hsr_self_node *sn;

	bool ret = false;



	node = list_first_or_null_rcu(&hsr->self_node_db, struct hsr_node,

				      mac_list);

	if (!node) {

	rcu_read_lock();

	sn = rcu_dereference(hsr->self_node);

	if (!sn) {

		WARN_ONCE(1, "HSR: No self node\n");

		return false;

		goto out;

	}



	if (ether_addr_equal(addr, node->macaddress_A))

		return true;

	if (ether_addr_equal(addr, node->macaddress_B))

		return true;



	return false;

	if (ether_addr_equal(addr, sn->macaddress_A) ||

	    ether_addr_equal(addr, sn->macaddress_B))

		ret = true;

out:

	rcu_read_unlock();

	return ret;

}



/* Search for mac entry. Caller must hold rcu read lock.
@@ -70,50 +71,42 @@ static struct hsr_node *find_node_by_addr_A(struct list_head *node_db, 
	return NULL;

}



/* Helper for device init; the self_node_db is used in hsr_rcv() to recognize

/* Helper for device init; the self_node is used in hsr_rcv() to recognize

 * frames from self that's been looped over the HSR ring.

 */

int hsr_create_self_node(struct hsr_priv *hsr,

			 const unsigned char addr_a[ETH_ALEN],

			 const unsigned char addr_b[ETH_ALEN])

{

	struct list_head *self_node_db = &hsr->self_node_db;

	struct hsr_node *node, *oldnode;

	struct hsr_self_node *sn, *old;



	node = kmalloc(sizeof(*node), GFP_KERNEL);

	if (!node)

	sn = kmalloc(sizeof(*sn), GFP_KERNEL);

	if (!sn)

		return -ENOMEM;



	ether_addr_copy(node->macaddress_A, addr_a);

	ether_addr_copy(node->macaddress_B, addr_b);

	ether_addr_copy(sn->macaddress_A, addr_a);

	ether_addr_copy(sn->macaddress_B, addr_b);



	spin_lock_bh(&hsr->list_lock);

	oldnode = list_first_or_null_rcu(self_node_db,

					 struct hsr_node, mac_list);

	if (oldnode) {

		list_replace_rcu(&oldnode->mac_list, &node->mac_list);

		spin_unlock_bh(&hsr->list_lock);

		kfree_rcu(oldnode, rcu_head);

	} else {

		list_add_tail_rcu(&node->mac_list, self_node_db);

	old = rcu_replace_pointer(hsr->self_node, sn,

				  lockdep_is_held(&hsr->list_lock));

	spin_unlock_bh(&hsr->list_lock);

	}



	if (old)

		kfree_rcu(old, rcu_head);

	return 0;

}



void hsr_del_self_node(struct hsr_priv *hsr)

{

	struct list_head *self_node_db = &hsr->self_node_db;

	struct hsr_node *node;

	struct hsr_self_node *old;



	spin_lock_bh(&hsr->list_lock);

	node = list_first_or_null_rcu(self_node_db, struct hsr_node, mac_list);

	if (node) {

		list_del_rcu(&node->mac_list);

		kfree_rcu(node, rcu_head);

	}

	old = rcu_replace_pointer(hsr->self_node, NULL,

				  lockdep_is_held(&hsr->list_lock));

	spin_unlock_bh(&hsr->list_lock);

	if (old)

		kfree_rcu(old, rcu_head);

}



void hsr_del_nodes(struct list_head *node_db)

net/hsr/hsr_main.h

+7 −1
Original line number Diff line number Diff line
@@ -182,11 +182,17 @@ struct hsr_proto_ops { 
	void (*update_san_info)(struct hsr_node *node, bool is_sup);

};



struct hsr_self_node {

	unsigned char	macaddress_A[ETH_ALEN];

	unsigned char	macaddress_B[ETH_ALEN];

	struct rcu_head	rcu_head;

};



struct hsr_priv {

	struct rcu_head		rcu_head;

	struct list_head	ports;

	struct list_head	node_db;	/* Known HSR nodes */

	struct list_head	self_node_db;	/* MACs of slaves */

	struct hsr_self_node	__rcu *self_node;	/* MACs of slaves */

	struct timer_list	announce_timer;	/* Supervision frame dispatch */

	struct timer_list	prune_timer;

	int announce_count;