tipc: relocate common functions from media to bearer

Currently, registering a TIPC stack handler in the network device layer
is done twice, once for Ethernet (eth_media) and Infiniband (ib_media)
repectively. But, as this registration is not media specific, we can
avoid some code duplication by moving the registering function to
the generic bearer layer, to the file bearer.c, and call it only once.
The same is true for the network device event notifier.

As a side effect, the two workqueues we are using for for setting up/
cleaning up media can now be eliminated. Furthermore, the array for
storing the specific media type structs, media_array[], can be entirely
deleted.

Note that the eth_started and ib_started flags were removed during the
code relocation.  There is now only one call to bearer_setup and
bearer_cleanup, and these can logically not race against each other.

Despite its size, this cleanup work incurs no functional changes in TIPC.
In particular, it should be noted that the sequence ordering of received
packets is unaffected by this change, since packet reception never was
subject to any work queue handling in the first place.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 189 deletions

diff --git a/net/tipc/ib_media.c b/net/tipc/ib_media.c
index 9fdf03cd672b..62d91aeda058 100644
--- a/net/tipc/ib_media.c
+++ b/net/tipc/ib_media.c
@@ -42,34 +42,6 @@
 #include "core.h"
 #include "bearer.h"
 
-#define MAX_IB_MEDIA		MAX_BEARERS
-
-/**
- * struct ib_media - Infiniband media data structure
- * @bearer: ptr to associated "generic" bearer structure
- * @dev: ptr to associated Infiniband network device
- * @tipc_packet_type: used in binding TIPC to Infiniband driver
- * @cleanup: work item used when disabling bearer
- */
-
-struct ib_media {
-	struct tipc_bearer *bearer;
-	struct net_device *dev;
-	struct packet_type tipc_packet_type;
-	struct work_struct setup;
-	struct work_struct cleanup;
-};
-
-static struct ib_media ib_media_array[MAX_IB_MEDIA];
-static int ib_started;
-static int recv_msg(struct sk_buff *buf, struct net_device *dev,
-		    struct packet_type *pt, struct net_device *orig_dev);
-
-static struct packet_type tipc_packet_type __read_mostly = {
-	.type = __constant_htons(ETH_P_TIPC),
-	.func = recv_msg,
-};
-
 /**
  * ib_media_addr_set - initialize Infiniband media address structure
  *
@@ -92,16 +64,14 @@ static int send_msg(struct sk_buff *buf, struct tipc_bearer *tb_ptr,
 		    struct tipc_media_addr *dest)
 {
 	struct sk_buff *clone;
-	struct net_device *dev;
 	int delta;
+	struct net_device *dev = tb_ptr->dev;
 
 	clone = skb_clone(buf, GFP_ATOMIC);
 	if (!clone)
 		return 0;
 
-	dev = ((struct ib_media *)(tb_ptr->usr_handle))->dev;
 	delta = dev->hard_header_len - skb_headroom(buf);
-
 	if ((delta > 0) &&
 	    pskb_expand_head(clone, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) {
 		kfree_skb(clone);
@@ -118,79 +88,21 @@ static int send_msg(struct sk_buff *buf, struct tipc_bearer *tb_ptr,
 }
 
 /**
- * recv_msg - handle incoming TIPC message from an InfiniBand interface
- *
- * Accept only packets explicitly sent to this node, or broadcast packets;
- * ignores packets sent using InfiniBand multicast, and traffic sent to other
- * nodes (which can happen if interface is running in promiscuous mode).
- */
-static int recv_msg(struct sk_buff *buf, struct net_device *dev,
-		    struct packet_type *pt, struct net_device *orig_dev)
-{
-	struct tipc_bearer *b_ptr;
-
-	if (!net_eq(dev_net(dev), &init_net)) {
-		kfree_skb(buf);
-		return NET_RX_DROP;
-	}
-
-	rcu_read_lock();
-	b_ptr = rcu_dereference(dev->tipc_ptr);
-	if (likely(b_ptr)) {
-		if (likely(buf->pkt_type <= PACKET_BROADCAST)) {
-			buf->next = NULL;
-			tipc_recv_msg(buf, b_ptr);
-			rcu_read_unlock();
-			return NET_RX_SUCCESS;
-		}
-	}
-	rcu_read_unlock();
-
-	kfree_skb(buf);
-	return NET_RX_DROP;
-}
-
-/**
- * setup_bearer - setup association between InfiniBand bearer and interface
- */
-static void setup_media(struct work_struct *work)
-{
-	dev_add_pack(&tipc_packet_type);
-}
-
-/**
  * enable_media - attach TIPC bearer to an InfiniBand interface
  */
 static int enable_media(struct tipc_bearer *tb_ptr)
 {
 	struct net_device *dev;
-	struct ib_media *ib_ptr = &ib_media_array[0];
-	struct ib_media *stop = &ib_media_array[MAX_IB_MEDIA];
 	char *driver_name = strchr((const char *)tb_ptr->name, ':') + 1;
-	int pending_dev = 0;
-
-	/* Find unused InfiniBand bearer structure */
-	while (ib_ptr->dev) {
-		if (!ib_ptr->bearer)
-			pending_dev++;
-		if (++ib_ptr == stop)
-			return pending_dev ? -EAGAIN : -EDQUOT;
-	}
 
 	/* Find device with specified name */
 	dev = dev_get_by_name(&init_net, driver_name);
 	if (!dev)
 		return -ENODEV;
 
-	/* Create InfiniBand bearer for device */
-	ib_ptr->dev = dev;
-	INIT_WORK(&ib_ptr->setup, setup_media);
-	schedule_work(&ib_ptr->setup);
-
 	/* Associate TIPC bearer with InfiniBand bearer */
 	tb_ptr->dev = dev;
-	ib_ptr->bearer = tb_ptr;
-	tb_ptr->usr_handle = (void *)ib_ptr;
+	tb_ptr->usr_handle = NULL;
 	memset(tb_ptr->bcast_addr.value, 0, sizeof(tb_ptr->bcast_addr.value));
 	memcpy(tb_ptr->bcast_addr.value, dev->broadcast, INFINIBAND_ALEN);
 	tb_ptr->bcast_addr.media_id = TIPC_MEDIA_TYPE_IB;
@@ -202,21 +114,6 @@ static int enable_media(struct tipc_bearer *tb_ptr)
 }
 
 /**
- * cleanup_bearer - break association between InfiniBand bearer and interface
- *
- * This routine must be invoked from a work queue because it can sleep.
- */
-static void cleanup_bearer(struct work_struct *work)
-{
-	struct ib_media *ib_ptr =
-		container_of(work, struct ib_media, cleanup);
-
-	dev_remove_pack(&tipc_packet_type);
-	dev_put(ib_ptr->dev);
-	ib_ptr->dev = NULL;
-}
-
-/**
  * disable_media - detach TIPC bearer from an InfiniBand interface
  *
  * Mark InfiniBand bearer as inactive so that incoming buffers are thrown away,
@@ -225,63 +122,11 @@ static void cleanup_bearer(struct work_struct *work)
  */
 static void disable_media(struct tipc_bearer *tb_ptr)
 {
-	struct ib_media *ib_ptr = (struct ib_media *)tb_ptr->usr_handle;
-
-	ib_ptr->bearer = NULL;
-	INIT_WORK(&ib_ptr->cleanup, cleanup_bearer);
-	schedule_work(&ib_ptr->cleanup);
 	RCU_INIT_POINTER(tb_ptr->dev->tipc_ptr, NULL);
+	dev_put(tb_ptr->dev);
 }
 
 /**
- * recv_notification - handle device updates from OS
- *
- * Change the state of the InfiniBand bearer (if any) associated with the
- * specified device.
- */
-static int recv_notification(struct notifier_block *nb, unsigned long evt,
-			     void *ptr)
-{
-	struct tipc_bearer *b_ptr;
-	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
-
-	if (!net_eq(dev_net(dev), &init_net))
-		return NOTIFY_DONE;
-
-	rcu_read_lock();
-	b_ptr = rcu_dereference(dev->tipc_ptr);
-	if (!b_ptr) {
-		rcu_read_unlock();
-		return NOTIFY_DONE;		/* bearer had been disabled */
-	}
-
-	b_ptr->mtu = dev->mtu;
-
-	switch (evt) {
-	case NETDEV_CHANGE:
-		if (netif_carrier_ok(dev))
-			break;
-	case NETDEV_DOWN:
-	case NETDEV_CHANGEMTU:
-	case NETDEV_CHANGEADDR:
-		tipc_reset_bearer(b_ptr);
-		break;
-	case NETDEV_UNREGISTER:
-	case NETDEV_CHANGENAME:
-		tipc_disable_bearer(b_ptr->name);
-		break;
-	}
-	rcu_read_unlock();
-
-	return NOTIFY_OK;
-}
-
-static struct notifier_block notifier = {
-	.notifier_call	= recv_notification,
-	.priority	= 0,
-};
-
-/**
  * ib_addr2str - convert InfiniBand address to string
  */
 static int ib_addr2str(struct tipc_media_addr *a, char *str_buf, int str_size)
@@ -332,34 +177,3 @@ struct tipc_media ib_media_info = {
 	.name		= "ib"
 };
 
-/**
- * tipc_ib_media_start - activate InfiniBand bearer support
- *
- * Register InfiniBand media type with TIPC bearer code.  Also register
- * with OS for notifications about device state changes.
- */
-int tipc_ib_media_start(void)
-{
-	int res;
-
-	if (ib_started)
-		return -EINVAL;
-
-	res = register_netdevice_notifier(&notifier);
-	if (!res)
-		ib_started = 1;
-	return res;
-}
-
-/**
- * tipc_ib_media_stop - deactivate InfiniBand bearer support
- */
-void tipc_ib_media_stop(void)
-{
-	if (!ib_started)
-		return;
-
-	flush_scheduled_work();
-	unregister_netdevice_notifier(&notifier);
-	ib_started = 0;
-}