Commit ac0d9176 authored by Vlad Buslov's avatar Vlad Buslov Committed by Saeed Mahameed
Browse files

net/mlx5e: Protect neigh hash encap list with spinlock and rcu 



Rcu-ify mlx5e_neigh_hash_entry->encap_list by changing operations on encap
list to their rcu counterparts and extending encap structure with rcu_head
to free the encap instances after rcu grace period. Use rcu read lock when
traversing encap list. Implement helper mlx5e_get_next_valid_encap()
function that is used by mlx5e_tc_update_neigh_used_value() to safely
iterate over valid entries of nhe->encap_list.

Signed-off-by: default avatarVlad Buslov <vladbu@mellanox.com>
Reviewed-by: default avatarJianbo Liu <jianbol@mellanox.com>
Reviewed-by: default avatarRoi Dayan <roid@mellanox.com>
Signed-off-by: default avatarSaeed Mahameed <saeedm@mellanox.com>
parent 70e83bd3

drivers/net/ethernet/mellanox/mlx5/core/en_rep.c

+8 −2
Original line number Diff line number Diff line
@@ -1064,6 +1064,7 @@ static int mlx5e_rep_neigh_entry_create(struct mlx5e_priv *priv, 
	(*nhe)->priv = priv;

	memcpy(&(*nhe)->m_neigh, &e->m_neigh, sizeof(e->m_neigh));

	INIT_WORK(&(*nhe)->neigh_update_work, mlx5e_rep_neigh_update);

	spin_lock_init(&(*nhe)->encap_list_lock);

	INIT_LIST_HEAD(&(*nhe)->encap_list);

	refcount_set(&(*nhe)->refcnt, 1);
@@ -1103,7 +1104,10 @@ int mlx5e_rep_encap_entry_attach(struct mlx5e_priv *priv, 
	}



	e->nhe = nhe;

	list_add(&e->encap_list, &nhe->encap_list);

	spin_lock(&nhe->encap_list_lock);

	list_add_rcu(&e->encap_list, &nhe->encap_list);

	spin_unlock(&nhe->encap_list_lock);



	mutex_unlock(&rpriv->neigh_update.encap_lock);



	return 0;
@@ -1119,7 +1123,9 @@ void mlx5e_rep_encap_entry_detach(struct mlx5e_priv *priv, 
	if (!e->nhe)

		return;



	list_del(&e->encap_list);

	spin_lock(&e->nhe->encap_list_lock);

	list_del_rcu(&e->encap_list);

	spin_unlock(&e->nhe->encap_list_lock);



	mlx5e_rep_neigh_entry_release(e->nhe);

	e->nhe = NULL;

drivers/net/ethernet/mellanox/mlx5/core/en_rep.h

+3 −0
Original line number Diff line number Diff line
@@ -119,6 +119,8 @@ struct mlx5e_neigh_hash_entry { 
	 */

	struct list_head neigh_list;



	/* protects encap list */

	spinlock_t encap_list_lock;

	/* encap list sharing the same neigh */

	struct list_head encap_list;
@@ -173,6 +175,7 @@ struct mlx5e_encap_entry { 
	refcount_t refcnt;

	struct completion res_ready;

	int compl_result;

	struct rcu_head rcu;

};



struct mlx5e_rep_sq {

drivers/net/ethernet/mellanox/mlx5/core/en_tc.c

+55 −9
Original line number Diff line number Diff line
@@ -1412,11 +1412,56 @@ static struct mlx5_fc *mlx5e_tc_get_counter(struct mlx5e_tc_flow *flow) 
		return flow->nic_attr->counter;

}



static struct mlx5e_encap_entry *

mlx5e_get_next_valid_encap(struct mlx5e_neigh_hash_entry *nhe,

			   struct mlx5e_encap_entry *e)

{

	struct mlx5e_encap_entry *next = NULL;



retry:

	rcu_read_lock();



	/* find encap with non-zero reference counter value */

	for (next = e ?

		     list_next_or_null_rcu(&nhe->encap_list,

					   &e->encap_list,

					   struct mlx5e_encap_entry,

					   encap_list) :

		     list_first_or_null_rcu(&nhe->encap_list,

					    struct mlx5e_encap_entry,

					    encap_list);

	     next;

	     next = list_next_or_null_rcu(&nhe->encap_list,

					  &next->encap_list,

					  struct mlx5e_encap_entry,

					  encap_list))

		if (mlx5e_encap_take(next))

			break;



	rcu_read_unlock();



	/* release starting encap */

	if (e)

		mlx5e_encap_put(netdev_priv(e->out_dev), e);

	if (!next)

		return next;



	/* wait for encap to be fully initialized */

	wait_for_completion(&next->res_ready);

	/* continue searching if encap entry is not in valid state after completion */

	if (!(next->flags & MLX5_ENCAP_ENTRY_VALID)) {

		e = next;

		goto retry;

	}



	return next;

}



void mlx5e_tc_update_neigh_used_value(struct mlx5e_neigh_hash_entry *nhe)

{

	struct mlx5e_neigh *m_neigh = &nhe->m_neigh;

	struct mlx5e_encap_entry *e = NULL;

	struct mlx5e_tc_flow *flow;

	struct mlx5e_encap_entry *e;

	struct mlx5_fc *counter;

	struct neigh_table *tbl;

	bool neigh_used = false;
@@ -1432,13 +1477,12 @@ void mlx5e_tc_update_neigh_used_value(struct mlx5e_neigh_hash_entry *nhe) 
	else

		return;



	list_for_each_entry(e, &nhe->encap_list, encap_list) {

	/* mlx5e_get_next_valid_encap() releases previous encap before returning

	 * next one.

	 */

	while ((e = mlx5e_get_next_valid_encap(nhe, e)) != NULL) {

		struct encap_flow_item *efi, *tmp;



		if (!(e->flags & MLX5_ENCAP_ENTRY_VALID) ||

		    !mlx5e_encap_take(e))

			continue;



		list_for_each_entry_safe(efi, tmp, &e->flows, list) {

			flow = container_of(efi, struct mlx5e_tc_flow,

					    encaps[efi->index]);
@@ -1458,10 +1502,12 @@ void mlx5e_tc_update_neigh_used_value(struct mlx5e_neigh_hash_entry *nhe) 
			mlx5e_flow_put(netdev_priv(e->out_dev), flow);

		}



		if (neigh_used) {

			/* release current encap before breaking the loop */

			mlx5e_encap_put(netdev_priv(e->out_dev), e);

		if (neigh_used)

			break;

		}

	}



	if (neigh_used) {

		nhe->reported_lastuse = jiffies;
@@ -1490,7 +1536,7 @@ static void mlx5e_encap_dealloc(struct mlx5e_priv *priv, struct mlx5e_encap_entr 
	}



	kfree(e->encap_header);

	kfree(e);

	kfree_rcu(e, rcu);

}



void mlx5e_encap_put(struct mlx5e_priv *priv, struct mlx5e_encap_entry *e)

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