5 files changed, 48 insertions, 18 deletions

diff --git a/drivers/infiniband/hw/cxgb3/iwch_cm.c b/drivers/infiniband/hw/cxgb3/iwch_cm.c
index 17bf9d95463c..6cd642aaa4de 100644
--- a/drivers/infiniband/hw/cxgb3/iwch_cm.c
+++ b/drivers/infiniband/hw/cxgb3/iwch_cm.c
@@ -287,7 +287,7 @@ void __free_ep(struct kref *kref)
         if (test_bit(RELEASE_RESOURCES, &ep->com.flags)) {
                 cxgb3_remove_tid(ep->com.tdev, (void *)ep, ep->hwtid);
                 dst_release(ep->dst);
-                l2t_release(L2DATA(ep->com.tdev), ep->l2t);
+                l2t_release(ep->com.tdev, ep->l2t);
         }
         kfree(ep);
 }
@@ -1178,7 +1178,7 @@ static int act_open_rpl(struct t3cdev *tdev, struct sk_buff *skb, void *ctx)
                 release_tid(ep->com.tdev, GET_TID(rpl), NULL);
         cxgb3_free_atid(ep->com.tdev, ep->atid);
         dst_release(ep->dst);
-        l2t_release(L2DATA(ep->com.tdev), ep->l2t);
+        l2t_release(ep->com.tdev, ep->l2t);
         put_ep(&ep->com);
         return CPL_RET_BUF_DONE;
 }
@@ -1377,7 +1377,7 @@ static int pass_accept_req(struct t3cdev *tdev, struct sk_buff *skb, void *ctx)
         if (!child_ep) {
                 printk(KERN_ERR MOD "%s - failed to allocate ep entry!\n",
                        __func__);
-                l2t_release(L2DATA(tdev), l2t);
+                l2t_release(tdev, l2t);
                 dst_release(dst);
                 goto reject;
         }
@@ -1956,7 +1956,7 @@ int iwch_connect(struct iw_cm_id *cm_id, struct iw_cm_conn_param *conn_param)
         if (!err)
                 goto out;
 
-        l2t_release(L2DATA(h->rdev.t3cdev_p), ep->l2t);
+        l2t_release(h->rdev.t3cdev_p, ep->l2t);
 fail4:
         dst_release(ep->dst);
 fail3:
@@ -2127,7 +2127,7 @@ int iwch_ep_redirect(void *ctx, struct dst_entry *old, struct dst_entry *new,
         PDBG("%s ep %p redirect to dst %p l2t %p\n", __func__, ep, new,
              l2t);
         dst_hold(new);
-        l2t_release(L2DATA(ep->com.tdev), ep->l2t);
+        l2t_release(ep->com.tdev, ep->l2t);
         ep->l2t = l2t;
         dst_release(old);
         ep->dst = new;
diff --git a/drivers/net/cxgb3/cxgb3_offload.c b/drivers/net/cxgb3/cxgb3_offload.c
index 805076c54f1b..da5a5d9b8aff 100644
--- a/drivers/net/cxgb3/cxgb3_offload.c
+++ b/drivers/net/cxgb3/cxgb3_offload.c
@@ -1146,12 +1146,14 @@ static void cxgb_redirect(struct dst_entry *old, struct dst_entry *new)
                 if (te && te->ctx && te->client && te->client->redirect) {
                         update_tcb = te->client->redirect(te->ctx, old, new, e);
                         if (update_tcb) {
+                                rcu_read_lock();
                                 l2t_hold(L2DATA(tdev), e);
+                                rcu_read_unlock();
                                 set_l2t_ix(tdev, tid, e);
                         }
                 }
         }
-        l2t_release(L2DATA(tdev), e);
+        l2t_release(tdev, e);
 }
 
 /*
@@ -1264,7 +1266,7 @@ int cxgb3_offload_activate(struct adapter *adapter)
                 goto out_free;
 
         err = -ENOMEM;
-        L2DATA(dev) = t3_init_l2t(l2t_capacity);
+        RCU_INIT_POINTER(dev->l2opt, t3_init_l2t(l2t_capacity));
         if (!L2DATA(dev))
                 goto out_free;
 
@@ -1298,16 +1300,24 @@ int cxgb3_offload_activate(struct adapter *adapter)
 
 out_free_l2t:
         t3_free_l2t(L2DATA(dev));
-        L2DATA(dev) = NULL;
+        rcu_assign_pointer(dev->l2opt, NULL);
 out_free:
         kfree(t);
         return err;
 }
 
+static void clean_l2_data(struct rcu_head *head)
+{
+        struct l2t_data *d = container_of(head, struct l2t_data, rcu_head);
+        t3_free_l2t(d);
+}
+
+
 void cxgb3_offload_deactivate(struct adapter *adapter)
 {
         struct t3cdev *tdev = &adapter->tdev;
         struct t3c_data *t = T3C_DATA(tdev);
+        struct l2t_data *d;
 
         remove_adapter(adapter);
         if (list_empty(&adapter_list))
@@ -1315,8 +1325,11 @@ void cxgb3_offload_deactivate(struct adapter *adapter)
 
         free_tid_maps(&t->tid_maps);
         T3C_DATA(tdev) = NULL;
-        t3_free_l2t(L2DATA(tdev));
-        L2DATA(tdev) = NULL;
+        rcu_read_lock();
+        d = L2DATA(tdev);
+        rcu_read_unlock();
+        rcu_assign_pointer(tdev->l2opt, NULL);
+        call_rcu(&d->rcu_head, clean_l2_data);
         if (t->nofail_skb)
                 kfree_skb(t->nofail_skb);
         kfree(t);
diff --git a/drivers/net/cxgb3/l2t.c b/drivers/net/cxgb3/l2t.c
index f452c4003253..41540978a173 100644
--- a/drivers/net/cxgb3/l2t.c
+++ b/drivers/net/cxgb3/l2t.c
@@ -300,14 +300,21 @@ static inline void reuse_entry(struct l2t_entry *e, struct neighbour *neigh)
 struct l2t_entry *t3_l2t_get(struct t3cdev *cdev, struct neighbour *neigh,
                              struct net_device *dev)
 {
-        struct l2t_entry *e;
-        struct l2t_data *d = L2DATA(cdev);
+        struct l2t_entry *e = NULL;
+        struct l2t_data *d;
+        int hash;
         u32 addr = *(u32 *) neigh->primary_key;
         int ifidx = neigh->dev->ifindex;
-        int hash = arp_hash(addr, ifidx, d);
         struct port_info *p = netdev_priv(dev);
         int smt_idx = p->port_id;
 
+        rcu_read_lock();
+        d = L2DATA(cdev);
+        if (!d)
+                goto done_rcu;
+
+        hash = arp_hash(addr, ifidx, d);
+
         write_lock_bh(&d->lock);
         for (e = d->l2tab[hash].first; e; e = e->next)
                 if (e->addr == addr && e->ifindex == ifidx &&
@@ -338,6 +345,8 @@ struct l2t_entry *t3_l2t_get(struct t3cdev *cdev, struct neighbour *neigh,
         }
 done:
         write_unlock_bh(&d->lock);
+done_rcu:
+        rcu_read_unlock();
         return e;
 }
 
diff --git a/drivers/net/cxgb3/l2t.h b/drivers/net/cxgb3/l2t.h
index 7a12d52ed4fc..c5f54796e2cb 100644
--- a/drivers/net/cxgb3/l2t.h
+++ b/drivers/net/cxgb3/l2t.h
@@ -76,6 +76,7 @@ struct l2t_data {
         atomic_t nfree;         /* number of free entries */
         rwlock_t lock;
         struct l2t_entry l2tab[0];
+        struct rcu_head rcu_head;       /* to handle rcu cleanup */
 };
 
 typedef void (*arp_failure_handler_func)(struct t3cdev * dev,
@@ -99,7 +100,7 @@ static inline void set_arp_failure_handler(struct sk_buff *skb,
 /*
  * Getting to the L2 data from an offload device.
  */
-#define L2DATA(dev) ((dev)->l2opt)
+#define L2DATA(cdev) (rcu_dereference((cdev)->l2opt))
 
 #define W_TCB_L2T_IX    0
 #define S_TCB_L2T_IX    7
@@ -126,15 +127,22 @@ static inline int l2t_send(struct t3cdev *dev, struct sk_buff *skb,
         return t3_l2t_send_slow(dev, skb, e);
 }
 
-static inline void l2t_release(struct l2t_data *d, struct l2t_entry *e)
+static inline void l2t_release(struct t3cdev *t, struct l2t_entry *e)
 {
-        if (atomic_dec_and_test(&e->refcnt))
+        struct l2t_data *d;
+
+        rcu_read_lock();
+        d = L2DATA(t);
+
+        if (atomic_dec_and_test(&e->refcnt) && d)
                 t3_l2e_free(d, e);
+
+        rcu_read_unlock();
 }
 
 static inline void l2t_hold(struct l2t_data *d, struct l2t_entry *e)
 {
-        if (atomic_add_return(1, &e->refcnt) == 1)      /* 0 -> 1 transition */
+        if (d && atomic_add_return(1, &e->refcnt) == 1) /* 0 -> 1 transition */
                 atomic_dec(&d->nfree);
 }
 
diff --git a/drivers/scsi/cxgbi/cxgb3i/cxgb3i.c b/drivers/scsi/cxgbi/cxgb3i/cxgb3i.c
index bd22041e2789..f58644850333 100644
--- a/drivers/scsi/cxgbi/cxgb3i/cxgb3i.c
+++ b/drivers/scsi/cxgbi/cxgb3i/cxgb3i.c
@@ -913,7 +913,7 @@ static void l2t_put(struct cxgbi_sock *csk)
         struct t3cdev *t3dev = (struct t3cdev *)csk->cdev->lldev;
 
         if (csk->l2t) {
-                l2t_release(L2DATA(t3dev), csk->l2t);
+                l2t_release(t3dev, csk->l2t);
                 csk->l2t = NULL;
                 cxgbi_sock_put(csk);
         }