[NETPOLL]: Introduce a netpoll_info struct

This patch introduces a netpoll_info structure, which the struct net_device
will now point to instead of pointing to a struct netpoll.  The reason for
this is two-fold: 1) fields such as the rx_flags, poll_owner, and poll_lock
should be maintained per net_device, not per netpoll;  and 2) this is a first
step in providing support for multiple netpoll clients to register against the
same net_device.

The struct netpoll is now pointed to by the netpoll_info structure.  As
such, the previous behaviour of the code is preserved.

Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 19 insertions, 10 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index ba5d1236aa17..d6afd440cf7b 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -41,7 +41,7 @@
 struct divert_blk;
 struct vlan_group;
 struct ethtool_ops;
-struct netpoll;
+struct netpoll_info;
                                         /* source back-compat hooks */
 #define SET_ETHTOOL_OPS(netdev,ops) \
         ( (netdev)->ethtool_ops = (ops) )
@@ -468,7 +468,7 @@ struct net_device
                                                      unsigned char *haddr);
         int                     (*neigh_setup)(struct net_device *dev, struct neigh_parms *);
 #ifdef CONFIG_NETPOLL
-        struct netpoll          *np;
+        struct netpoll_info     *npinfo;
 #endif
 #ifdef CONFIG_NET_POLL_CONTROLLER
         void                    (*poll_controller)(struct net_device *dev);
diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h
index 449a4fde6587..388cd91bc7a6 100644
--- a/include/linux/netpoll.h
+++ b/include/linux/netpoll.h
@@ -16,14 +16,18 @@ struct netpoll;
 struct netpoll {
         struct net_device *dev;
         char dev_name[16], *name;
-        int rx_flags;
         void (*rx_hook)(struct netpoll *, int, char *, int);
         void (*drop)(struct sk_buff *skb);
         u32 local_ip, remote_ip;
         u16 local_port, remote_port;
         unsigned char local_mac[6], remote_mac[6];
+};
+
+struct netpoll_info {
         spinlock_t poll_lock;
         int poll_owner;
+        int rx_flags;
+        struct netpoll *np;
 };
 
 void netpoll_poll(struct netpoll *np);
@@ -39,22 +43,27 @@ void netpoll_queue(struct sk_buff *skb);
 #ifdef CONFIG_NETPOLL
 static inline int netpoll_rx(struct sk_buff *skb)
 {
-        return skb->dev->np && skb->dev->np->rx_flags && __netpoll_rx(skb);
+        struct netpoll_info *npinfo = skb->dev->npinfo;
+
+        if (!npinfo || !npinfo->rx_flags)
+                return 0;
+
+        return npinfo->np && __netpoll_rx(skb);
 }
 
 static inline void netpoll_poll_lock(struct net_device *dev)
 {
-        if (dev->np) {
-                spin_lock(&dev->np->poll_lock);
-                dev->np->poll_owner = smp_processor_id();
+        if (dev->npinfo) {
+                spin_lock(&dev->npinfo->poll_lock);
+                dev->npinfo->poll_owner = smp_processor_id();
         }
 }
 
 static inline void netpoll_poll_unlock(struct net_device *dev)
 {
-        if (dev->np) {
-                dev->np->poll_owner = -1;
-                spin_unlock(&dev->np->poll_lock);
+        if (dev->npinfo) {
+                dev->npinfo->poll_owner = -1;
+                spin_unlock(&dev->npinfo->poll_lock);
         }
 }