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         struct list_head rx; /* rx_np list element */
  26 };
  27
  28 struct netpoll_info {
  29         atomic_t refcnt;
  30
  31         int rx_flags;
  32         spinlock_t rx_lock;
  33         struct list_head rx_np; /* netpolls that registered an rx_hook */
  34
  35         struct sk_buff_head arp_tx; /* list of arp requests to reply to */
  36         struct sk_buff_head txq;
  37
  38         struct delayed_work tx_work;
  39 };
  40
  41 void netpoll_poll(struct netpoll *np);
  42 void netpoll_send_udp(struct netpoll *np, const char *msg, int len);
  43 void netpoll_print_options(struct netpoll *np);
  44 int netpoll_parse_options(struct netpoll *np, char *opt);
  45 int netpoll_setup(struct netpoll *np);
  46 int netpoll_trap(void);
  47 void netpoll_set_trap(int trap);
  48 void netpoll_cleanup(struct netpoll *np);
  49 int __netpoll_rx(struct sk_buff *skb);
  50
  51
  52 #ifdef CONFIG_NETPOLL
  53 static inline int netpoll_rx(struct sk_buff *skb)
  54 {
  55         struct netpoll_info *npinfo = skb->dev->npinfo;
  56         unsigned long flags;
  57         int ret = 0;
  58
  59         if (!npinfo || (list_empty(&npinfo->rx_np) && !npinfo->rx_flags))
  60                 return 0;
  61
  62         spin_lock_irqsave(&npinfo->rx_lock, flags);
  63         /* check rx_flags again with the lock held */
  64         if (npinfo->rx_flags && __netpoll_rx(skb))
  65                 ret = 1;
  66         spin_unlock_irqrestore(&npinfo->rx_lock, flags);
  67
  68         return ret;
  69 }
  70
  71 static inline int netpoll_rx_on(struct sk_buff *skb)
  72 {
  73         struct netpoll_info *npinfo = skb->dev->npinfo;
  74
  75         return npinfo && (!list_empty(&npinfo->rx_np) || npinfo->rx_flags);
  76 }
  77
  78 static inline int netpoll_receive_skb(struct sk_buff *skb)
  79 {
  80         if (!list_empty(&skb->dev->napi_list))
  81                 return netpoll_rx(skb);
  82         return 0;
  83 }
  84
  85 static inline void *netpoll_poll_lock(struct napi_struct *napi)
  86 {
  87         struct net_device *dev = napi->dev;
  88
  89         rcu_read_lock(); /* deal with race on ->npinfo */
  90         if (dev && dev->npinfo) {
  91                 spin_lock(&napi->poll_lock);
  92                 napi->poll_owner = smp_processor_id();
  93                 return napi;
  94         }
  95         return NULL;
  96 }
  97
  98 static inline void netpoll_poll_unlock(void *have)
  99 {
 100         struct napi_struct *napi = have;
 101
 102         if (napi) {
 103                 napi->poll_owner = -1;
 104                 spin_unlock(&napi->poll_lock);
 105         }
 106         rcu_read_unlock();
 107 }
 108
 109 #else
 110 static inline int netpoll_rx(struct sk_buff *skb)
 111 {
 112         return 0;
 113 }
 114 static inline int netpoll_rx_on(struct sk_buff *skb)
 115 {
 116         return 0;
 117 }
 118 static inline int netpoll_receive_skb(struct sk_buff *skb)
 119 {
 120         return 0;
 121 }
 122 static inline void *netpoll_poll_lock(struct napi_struct *napi)
 123 {
 124         return NULL;
 125 }
 126 static inline void netpoll_poll_unlock(void *have)
 127 {
 128 }
 129 static inline void netpoll_netdev_init(struct net_device *dev)
 130 {
 131 }
 132 #endif
 133
 134 #endif