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 remote_mac[ETH_ALEN];
  24 };
  25
  26 struct netpoll_info {
  27         atomic_t refcnt;
  28         spinlock_t rx_lock;
  29         struct netpoll *rx_np; /* netpoll that registered an rx_hook */
  30         struct sk_buff_head arp_tx; /* list of arp requests to reply to */
  31         struct sk_buff_head txq;
  32         struct delayed_work tx_work;
  33 };
  34
  35 void netpoll_poll(struct netpoll *np);
  36 void netpoll_send_udp(struct netpoll *np, const char *msg, int len);
  37 void netpoll_print_options(struct netpoll *np);
  38 int netpoll_parse_options(struct netpoll *np, char *opt);
  39 int netpoll_setup(struct netpoll *np);
  40 int netpoll_trap(void);
  41 void netpoll_set_trap(int trap);
  42 void netpoll_cleanup(struct netpoll *np);
  43 int __netpoll_rx(struct sk_buff *skb);
  44
  45
  46 #ifdef CONFIG_NETPOLL
  47 static inline int netpoll_rx(struct sk_buff *skb)
  48 {
  49         struct netpoll_info *npinfo = skb->dev->npinfo;
  50         unsigned long flags;
  51         int ret = 0;
  52
  53         if (!npinfo || !npinfo->rx_np)
  54                 return 0;
  55
  56         spin_lock_irqsave(&npinfo->rx_lock, flags);
  57         /* check rx_np again with the lock held */
  58         if (npinfo->rx_np && __netpoll_rx(skb))
  59                 ret = 1;
  60         spin_unlock_irqrestore(&npinfo->rx_lock, flags);
  61
  62         return ret;
  63 }
  64
  65 static inline int netpoll_receive_skb(struct sk_buff *skb)
  66 {
  67         if (!list_empty(&skb->dev->napi_list))
  68                 return netpoll_rx(skb);
  69         return 0;
  70 }
  71
  72 static inline void *netpoll_poll_lock(struct napi_struct *napi)
  73 {
  74         struct net_device *dev = napi->dev;
  75
  76         rcu_read_lock(); /* deal with race on ->npinfo */
  77         if (dev && dev->npinfo) {
  78                 spin_lock(&napi->poll_lock);
  79                 napi->poll_owner = smp_processor_id();
  80                 return napi;
  81         }
  82         return NULL;
  83 }
  84
  85 static inline void netpoll_poll_unlock(void *have)
  86 {
  87         struct napi_struct *napi = have;
  88
  89         if (napi) {
  90                 napi->poll_owner = -1;
  91                 spin_unlock(&napi->poll_lock);
  92         }
  93         rcu_read_unlock();
  94 }
  95
  96 static inline void netpoll_netdev_init(struct net_device *dev)
  97 {
  98         INIT_LIST_HEAD(&dev->napi_list);
  99 }
 100
 101 #else
 102 static inline int netpoll_rx(struct sk_buff *skb)
 103 {
 104         return 0;
 105 }
 106 static inline int netpoll_receive_skb(struct sk_buff *skb)
 107 {
 108         return 0;
 109 }
 110 static inline void *netpoll_poll_lock(struct napi_struct *napi)
 111 {
 112         return NULL;
 113 }
 114 static inline void netpoll_poll_unlock(void *have)
 115 {
 116 }
 117 static inline void netpoll_netdev_init(struct net_device *dev)
 118 {
 119 }
 120 #endif
 121
 122 #endif