include/linux/netpoll.h

   1 /*
   2  * Common code for low-level network console, dump, and debugger code
   3  *
   4  * Derived from netconsole, kgdb-over-ethernet, and netdump patches
   5  */
   6
   7 #ifndef _LINUX_NETPOLL_H
   8 #define _LINUX_NETPOLL_H
   9
  10 #include <linux/netdevice.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/rcupdate.h>
  13 #include <linux/list.h>
  14
  15 struct netpoll {
  16         struct net_device *dev;
  17         char dev_name[IFNAMSIZ];
  18         const char *name;
  19         void (*rx_hook)(struct netpoll *, int, char *, int);
  20
  21         u32 local_ip, remote_ip;
  22         u16 local_port, remote_port;
  23         u8 local_mac[ETH_ALEN], remote_mac[ETH_ALEN];
  24 };
  25
  26 struct netpoll_info {
  27         atomic_t refcnt;
  28         spinlock_t poll_lock;
  29         int poll_owner;
  30         int rx_flags;
  31         spinlock_t rx_lock;
  32         struct netpoll *rx_np; /* netpoll that registered an rx_hook */
  33         struct sk_buff_head arp_tx; /* list of arp requests to reply to */
  34         struct sk_buff_head txq;
  35         struct delayed_work tx_work;
  36 };
  37
  38 void netpoll_poll(struct netpoll *np);
  39 void netpoll_send_udp(struct netpoll *np, const char *msg, int len);
  40 int netpoll_parse_options(struct netpoll *np, char *opt);
  41 int netpoll_setup(struct netpoll *np);
  42 int netpoll_trap(void);
  43 void netpoll_set_trap(int trap);
  44 void netpoll_cleanup(struct netpoll *np);
  45 int __netpoll_rx(struct sk_buff *skb);
  46
  47
  48 #ifdef CONFIG_NETPOLL
  49 static inline int netpoll_rx(struct sk_buff *skb)
  50 {
  51         struct netpoll_info *npinfo = skb->dev->npinfo;
  52         unsigned long flags;
  53         int ret = 0;
  54
  55         if (!npinfo || (!npinfo->rx_np && !npinfo->rx_flags))
  56                 return 0;
  57
  58         spin_lock_irqsave(&npinfo->rx_lock, flags);
  59         /* check rx_flags again with the lock held */
  60         if (npinfo->rx_flags && __netpoll_rx(skb))
  61                 ret = 1;
  62         spin_unlock_irqrestore(&npinfo->rx_lock, flags);
  63
  64         return ret;
  65 }
  66
  67 static inline void *netpoll_poll_lock(struct net_device *dev)
  68 {
  69         rcu_read_lock(); /* deal with race on ->npinfo */
  70         if (dev->npinfo) {
  71                 spin_lock(&dev->npinfo->poll_lock);
  72                 dev->npinfo->poll_owner = smp_processor_id();
  73                 return dev->npinfo;
  74         }
  75         return NULL;
  76 }
  77
  78 static inline void netpoll_poll_unlock(void *have)
  79 {
  80         struct netpoll_info *npi = have;
  81
  82         if (npi) {
  83                 npi->poll_owner = -1;
  84                 spin_unlock(&npi->poll_lock);
  85         }
  86         rcu_read_unlock();
  87 }
  88
  89 #else
  90 #define netpoll_rx(a) 0
  91 #define netpoll_poll_lock(a) NULL
  92 #define netpoll_poll_unlock(a)
  93 #endif
  94
  95 #endif