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         __be32 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         int rx_flags;
  29         spinlock_t rx_lock;
  30         struct netpoll *rx_np; /* netpoll that registered an rx_hook */
  31         struct sk_buff_head arp_tx; /* list of arp requests to reply to */
  32         struct sk_buff_head txq;
  33         struct delayed_work tx_work;
  34 };
  35
  36 void netpoll_poll(struct netpoll *np);
  37 void netpoll_send_udp(struct netpoll *np, const char *msg, int len);
  38 void netpoll_print_options(struct netpoll *np);
  39 int netpoll_parse_options(struct netpoll *np, char *opt);
  40 int netpoll_setup(struct netpoll *np);
  41 int netpoll_trap(void);
  42 void netpoll_set_trap(int trap);
  43 void netpoll_cleanup(struct netpoll *np);
  44 int __netpoll_rx(struct sk_buff *skb);
  45
  46
  47 #ifdef CONFIG_NETPOLL
  48 static inline int netpoll_rx(struct sk_buff *skb)
  49 {
  50         struct netpoll_info *npinfo = skb->dev->npinfo;
  51         unsigned long flags;
  52         int ret = 0;
  53
  54         if (!npinfo || (!npinfo->rx_np && !npinfo->rx_flags))
  55                 return 0;
  56
  57         spin_lock_irqsave(&npinfo->rx_lock, flags);
  58         /* check rx_flags again with the lock held */
  59         if (npinfo->rx_flags && __netpoll_rx(skb))
  60                 ret = 1;
  61         spin_unlock_irqrestore(&npinfo->rx_lock, flags);
  62
  63         return ret;
  64 }
  65
  66 static inline int netpoll_rx_on(struct sk_buff *skb)
  67 {
  68         struct netpoll_info *npinfo = skb->dev->npinfo;
  69
  70         return npinfo && (npinfo->rx_np || npinfo->rx_flags);
  71 }
  72
  73 static inline int netpoll_receive_skb(struct sk_buff *skb)
  74 {
  75         if (!list_empty(&skb->dev->napi_list))
  76                 return netpoll_rx(skb);
  77         return 0;
  78 }
  79
  80 static inline void *netpoll_poll_lock(struct napi_struct *napi)
  81 {
  82         struct net_device *dev = napi->dev;
  83
  84         rcu_read_lock(); /* deal with race on ->npinfo */
  85         if (dev && dev->npinfo) {
  86                 spin_lock(&napi->poll_lock);
  87                 napi->poll_owner = smp_processor_id();
  88                 return napi;
  89         }
  90         return NULL;
  91 }
  92
  93 static inline void netpoll_poll_unlock(void *have)
  94 {
  95         struct napi_struct *napi = have;
  96
  97         if (napi) {
  98                 napi->poll_owner = -1;
  99                 spin_unlock(&napi->poll_lock);
 100         }
 101         rcu_read_unlock();
 102 }
 103
 104 #else
 105 static inline int netpoll_rx(struct sk_buff *skb)
 106 {
 107         return 0;
 108 }
 109 static inline int netpoll_rx_on(struct sk_buff *skb)
 110 {
 111         return 0;
 112 }
 113 static inline int netpoll_receive_skb(struct sk_buff *skb)
 114 {
 115         return 0;
 116 }
 117 static inline void *netpoll_poll_lock(struct napi_struct *napi)
 118 {
 119         return NULL;
 120 }
 121 static inline void netpoll_poll_unlock(void *have)
 122 {
 123 }
 124 static inline void netpoll_netdev_init(struct net_device *dev)
 125 {
 126 }
 127 #endif
 128
 129 #endif