s390/qeth: remove locking for RX modeset cache

The L2 and L3 .ndo_set_rx_mode callbacks maintain an address cache
to decide which addresses have changed since the last modeset.

When the card is set offline, qeth_l?_stop_card() drains this cache.
This happens only after 1) the net_device has been detached, and
2) any pending RX modeset has completed. Consequently we can access the
cache lock-free.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h
index c3cf992..e6e365a 100644 (file)
--- a/drivers/s390/net/qeth_core.h
+++ b/drivers/s390/net/qeth_core.h
@@ -775,7 +775,6 @@ struct qeth_card {
 
        struct workqueue_struct *event_wq;
        wait_queue_head_t wait_q;
-       spinlock_t mclock;
        unsigned long active_vlans[BITS_TO_LONGS(VLAN_N_VID)];
        DECLARE_HASHTABLE(mac_htable, 4);
        DECLARE_HASHTABLE(ip_htable, 4);

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 44bd6f0..717ca21 100644 (file)
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -1409,7 +1409,6 @@ static void qeth_setup_card(struct qeth_card *card)
 
        card->info.type = CARD_RDEV(card)->id.driver_info;
        card->state = CARD_STATE_DOWN;
-       spin_lock_init(&card->mclock);
        spin_lock_init(&card->lock);
        spin_lock_init(&card->ip_lock);
        spin_lock_init(&card->thread_mask_lock);

diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c
index 437a399..918c3e2 100644 (file)
--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -155,12 +155,10 @@ static void qeth_l2_drain_rx_mode_cache(struct qeth_card *card)
        struct hlist_node *tmp;
        int i;
 
-       spin_lock_bh(&card->mclock);
        hash_for_each_safe(card->mac_htable, i, tmp, mac, hnode) {
                hash_del(&mac->hnode);
                kfree(mac);
        }
-       spin_unlock_bh(&card->mclock);
 }
 
 static int qeth_l2_get_cast_type(struct qeth_card *card, struct sk_buff *skb)
@@ -530,8 +528,6 @@ static void qeth_l2_rx_mode_work(struct work_struct *work)
 
        QETH_CARD_TEXT(card, 3, "setmulti");
 
-       spin_lock_bh(&card->mclock);
-
        netif_addr_lock_bh(dev);
        netdev_for_each_mc_addr(ha, dev)
                qeth_l2_add_mac(card, ha);
@@ -560,8 +556,6 @@ static void qeth_l2_rx_mode_work(struct work_struct *work)
                }
        }
 
-       spin_unlock_bh(&card->mclock);
-
        if (qeth_adp_supported(card, IPA_SETADP_SET_PROMISC_MODE))
                qeth_setadp_promisc_mode(card);
        else

diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c
index b6df38f..7e32eda 100644 (file)
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -274,12 +274,10 @@ static void qeth_l3_drain_rx_mode_cache(struct qeth_card *card)
        struct hlist_node *tmp;
        int i;
 
-       spin_lock_bh(&card->mclock);
        hash_for_each_safe(card->ip_mc_htable, i, tmp, addr, hnode) {
                hash_del(&addr->hnode);
                kfree(addr);
        }
-       spin_unlock_bh(&card->mclock);
 }
 
 static void qeth_l3_clear_ip_htable(struct qeth_card *card, int recover)
@@ -1484,8 +1482,6 @@ static void qeth_l3_rx_mode_work(struct work_struct *work)
        QETH_CARD_TEXT(card, 3, "setmulti");
 
        if (!card->options.sniffer) {
-               spin_lock_bh(&card->mclock);
-
                qeth_l3_add_multicast_ipv4(card);
                qeth_l3_add_multicast_ipv6(card);
 
@@ -1513,8 +1509,6 @@ static void qeth_l3_rx_mode_work(struct work_struct *work)
                        }
                }
 
-               spin_unlock_bh(&card->mclock);
-
                if (!qeth_adp_supported(card, IPA_SETADP_SET_PROMISC_MODE))
                        return;
        }