s390/qeth: process local address events

In configurations where specific HW offloads are in use, OSA adapters
will raise notifications to their virtual devices about the IP addresses
that currently reside on the same adapter.
Cache these addresses in two RCU-enabled hash tables, and flush the
tables once the relevant HW offload(s) get disabled.

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

1 files changed, 217 insertions, 0 deletions

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index ef96890eea5c..6b5d42a4501c 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -26,6 +26,7 @@
 #include <linux/if_vlan.h>
 #include <linux/netdevice.h>
 #include <linux/netdev_features.h>
+#include <linux/rcutree.h>
 #include <linux/skbuff.h>
 #include <linux/vmalloc.h>
 
@@ -623,6 +624,187 @@ void qeth_notify_cmd(struct qeth_cmd_buffer *iob, int reason)
 }
 EXPORT_SYMBOL_GPL(qeth_notify_cmd);
 
+static void qeth_flush_local_addrs4(struct qeth_card *card)
+{
+	struct qeth_local_addr *addr;
+	struct hlist_node *tmp;
+	unsigned int i;
+
+	spin_lock_irq(&card->local_addrs4_lock);
+	hash_for_each_safe(card->local_addrs4, i, tmp, addr, hnode) {
+		hash_del_rcu(&addr->hnode);
+		kfree_rcu(addr, rcu);
+	}
+	spin_unlock_irq(&card->local_addrs4_lock);
+}
+
+static void qeth_flush_local_addrs6(struct qeth_card *card)
+{
+	struct qeth_local_addr *addr;
+	struct hlist_node *tmp;
+	unsigned int i;
+
+	spin_lock_irq(&card->local_addrs6_lock);
+	hash_for_each_safe(card->local_addrs6, i, tmp, addr, hnode) {
+		hash_del_rcu(&addr->hnode);
+		kfree_rcu(addr, rcu);
+	}
+	spin_unlock_irq(&card->local_addrs6_lock);
+}
+
+void qeth_flush_local_addrs(struct qeth_card *card)
+{
+	qeth_flush_local_addrs4(card);
+	qeth_flush_local_addrs6(card);
+}
+EXPORT_SYMBOL_GPL(qeth_flush_local_addrs);
+
+static void qeth_add_local_addrs4(struct qeth_card *card,
+				  struct qeth_ipacmd_local_addrs4 *cmd)
+{
+	unsigned int i;
+
+	if (cmd->addr_length !=
+	    sizeof_field(struct qeth_ipacmd_local_addr4, addr)) {
+		dev_err_ratelimited(&card->gdev->dev,
+				    "Dropped IPv4 ADD LOCAL ADDR event with bad length %u\n",
+				    cmd->addr_length);
+		return;
+	}
+
+	spin_lock(&card->local_addrs4_lock);
+	for (i = 0; i < cmd->count; i++) {
+		unsigned int key = ipv4_addr_hash(cmd->addrs[i].addr);
+		struct qeth_local_addr *addr;
+		bool duplicate = false;
+
+		hash_for_each_possible(card->local_addrs4, addr, hnode, key) {
+			if (addr->addr.s6_addr32[3] == cmd->addrs[i].addr) {
+				duplicate = true;
+				break;
+			}
+		}
+
+		if (duplicate)
+			continue;
+
+		addr = kmalloc(sizeof(*addr), GFP_ATOMIC);
+		if (!addr) {
+			dev_err(&card->gdev->dev,
+				"Failed to allocate local addr object. Traffic to %pI4 might suffer.\n",
+				&cmd->addrs[i].addr);
+			continue;
+		}
+
+		ipv6_addr_set(&addr->addr, 0, 0, 0, cmd->addrs[i].addr);
+		hash_add_rcu(card->local_addrs4, &addr->hnode, key);
+	}
+	spin_unlock(&card->local_addrs4_lock);
+}
+
+static void qeth_add_local_addrs6(struct qeth_card *card,
+				  struct qeth_ipacmd_local_addrs6 *cmd)
+{
+	unsigned int i;
+
+	if (cmd->addr_length !=
+	    sizeof_field(struct qeth_ipacmd_local_addr6, addr)) {
+		dev_err_ratelimited(&card->gdev->dev,
+				    "Dropped IPv6 ADD LOCAL ADDR event with bad length %u\n",
+				    cmd->addr_length);
+		return;
+	}
+
+	spin_lock(&card->local_addrs6_lock);
+	for (i = 0; i < cmd->count; i++) {
+		u32 key = ipv6_addr_hash(&cmd->addrs[i].addr);
+		struct qeth_local_addr *addr;
+		bool duplicate = false;
+
+		hash_for_each_possible(card->local_addrs6, addr, hnode, key) {
+			if (ipv6_addr_equal(&addr->addr, &cmd->addrs[i].addr)) {
+				duplicate = true;
+				break;
+			}
+		}
+
+		if (duplicate)
+			continue;
+
+		addr = kmalloc(sizeof(*addr), GFP_ATOMIC);
+		if (!addr) {
+			dev_err(&card->gdev->dev,
+				"Failed to allocate local addr object. Traffic to %pI6c might suffer.\n",
+				&cmd->addrs[i].addr);
+			continue;
+		}
+
+		addr->addr = cmd->addrs[i].addr;
+		hash_add_rcu(card->local_addrs6, &addr->hnode, key);
+	}
+	spin_unlock(&card->local_addrs6_lock);
+}
+
+static void qeth_del_local_addrs4(struct qeth_card *card,
+				  struct qeth_ipacmd_local_addrs4 *cmd)
+{
+	unsigned int i;
+
+	if (cmd->addr_length !=
+	    sizeof_field(struct qeth_ipacmd_local_addr4, addr)) {
+		dev_err_ratelimited(&card->gdev->dev,
+				    "Dropped IPv4 DEL LOCAL ADDR event with bad length %u\n",
+				    cmd->addr_length);
+		return;
+	}
+
+	spin_lock(&card->local_addrs4_lock);
+	for (i = 0; i < cmd->count; i++) {
+		struct qeth_ipacmd_local_addr4 *addr = &cmd->addrs[i];
+		unsigned int key = ipv4_addr_hash(addr->addr);
+		struct qeth_local_addr *tmp;
+
+		hash_for_each_possible(card->local_addrs4, tmp, hnode, key) {
+			if (tmp->addr.s6_addr32[3] == addr->addr) {
+				hash_del_rcu(&tmp->hnode);
+				kfree_rcu(tmp, rcu);
+				break;
+			}
+		}
+	}
+	spin_unlock(&card->local_addrs4_lock);
+}
+
+static void qeth_del_local_addrs6(struct qeth_card *card,
+				  struct qeth_ipacmd_local_addrs6 *cmd)
+{
+	unsigned int i;
+
+	if (cmd->addr_length !=
+	    sizeof_field(struct qeth_ipacmd_local_addr6, addr)) {
+		dev_err_ratelimited(&card->gdev->dev,
+				    "Dropped IPv6 DEL LOCAL ADDR event with bad length %u\n",
+				    cmd->addr_length);
+		return;
+	}
+
+	spin_lock(&card->local_addrs6_lock);
+	for (i = 0; i < cmd->count; i++) {
+		struct qeth_ipacmd_local_addr6 *addr = &cmd->addrs[i];
+		u32 key = ipv6_addr_hash(&addr->addr);
+		struct qeth_local_addr *tmp;
+
+		hash_for_each_possible(card->local_addrs6, tmp, hnode, key) {
+			if (ipv6_addr_equal(&tmp->addr, &addr->addr)) {
+				hash_del_rcu(&tmp->hnode);
+				kfree_rcu(tmp, rcu);
+				break;
+			}
+		}
+	}
+	spin_unlock(&card->local_addrs6_lock);
+}
+
 static void qeth_issue_ipa_msg(struct qeth_ipa_cmd *cmd, int rc,
 		struct qeth_card *card)
 {
@@ -686,9 +868,19 @@ static struct qeth_ipa_cmd *qeth_check_ipa_data(struct qeth_card *card,
 	case IPA_CMD_MODCCID:
 		return cmd;
 	case IPA_CMD_REGISTER_LOCAL_ADDR:
+		if (cmd->hdr.prot_version == QETH_PROT_IPV4)
+			qeth_add_local_addrs4(card, &cmd->data.local_addrs4);
+		else if (cmd->hdr.prot_version == QETH_PROT_IPV6)
+			qeth_add_local_addrs6(card, &cmd->data.local_addrs6);
+
 		QETH_CARD_TEXT(card, 3, "irla");
 		return NULL;
 	case IPA_CMD_UNREGISTER_LOCAL_ADDR:
+		if (cmd->hdr.prot_version == QETH_PROT_IPV4)
+			qeth_del_local_addrs4(card, &cmd->data.local_addrs4);
+		else if (cmd->hdr.prot_version == QETH_PROT_IPV6)
+			qeth_del_local_addrs6(card, &cmd->data.local_addrs6);
+
 		QETH_CARD_TEXT(card, 3, "urla");
 		return NULL;
 	default:
@@ -1376,6 +1568,10 @@ static void qeth_setup_card(struct qeth_card *card)
 	qeth_init_qdio_info(card);
 	INIT_DELAYED_WORK(&card->buffer_reclaim_work, qeth_buffer_reclaim_work);
 	INIT_WORK(&card->close_dev_work, qeth_close_dev_handler);
+	hash_init(card->local_addrs4);
+	hash_init(card->local_addrs6);
+	spin_lock_init(&card->local_addrs4_lock);
+	spin_lock_init(&card->local_addrs6_lock);
 }
 
 static void qeth_core_sl_print(struct seq_file *m, struct service_level *slr)
@@ -6496,6 +6692,24 @@ void qeth_enable_hw_features(struct net_device *dev)
 }
 EXPORT_SYMBOL_GPL(qeth_enable_hw_features);
 
+static void qeth_check_restricted_features(struct qeth_card *card,
+					   netdev_features_t changed,
+					   netdev_features_t actual)
+{
+	netdev_features_t ipv6_features = NETIF_F_TSO6;
+	netdev_features_t ipv4_features = NETIF_F_TSO;
+
+	if (!card->info.has_lp2lp_cso_v6)
+		ipv6_features |= NETIF_F_IPV6_CSUM;
+	if (!card->info.has_lp2lp_cso_v4)
+		ipv4_features |= NETIF_F_IP_CSUM;
+
+	if ((changed & ipv6_features) && !(actual & ipv6_features))
+		qeth_flush_local_addrs6(card);
+	if ((changed & ipv4_features) && !(actual & ipv4_features))
+		qeth_flush_local_addrs4(card);
+}
+
 int qeth_set_features(struct net_device *dev, netdev_features_t features)
 {
 	struct qeth_card *card = dev->ml_priv;
@@ -6537,6 +6751,9 @@ int qeth_set_features(struct net_device *dev, netdev_features_t features)
 			changed ^= NETIF_F_TSO6;
 	}
 
+	qeth_check_restricted_features(card, dev->features ^ features,
+				       dev->features ^ changed);
+
 	/* everything changed successfully? */
 	if ((dev->features ^ features) == changed)
 		return 0;