release/src-rt-6.x.4708/linux/linux-2.6.36/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         struct net_device *real_dev;
  18         char dev_name[IFNAMSIZ];
  19         const char *name;
  20         void (*rx_hook)(struct netpoll *, int, char *, int);
  21
  22         __be32 local_ip, remote_ip;
  23         u16 local_port, remote_port;
  24         u8 remote_mac[ETH_ALEN];
  25
  26         struct list_head rx; /* rx_np list element */
  27 };
  28
  29 struct netpoll_info {
  30         atomic_t refcnt;
  31
  32         int rx_flags;
  33         spinlock_t rx_lock;
  34         struct list_head rx_np; /* netpolls that registered an rx_hook */
  35
  36         struct sk_buff_head arp_tx; /* list of arp requests to reply to */
  37         struct sk_buff_head txq;
  38
  39         struct delayed_work tx_work;
  40
  41         struct netpoll *netpoll;
  42 };
  43
  44 void netpoll_poll_dev(struct net_device *dev);
  45 void netpoll_poll(struct netpoll *np);
  46 void netpoll_send_udp(struct netpoll *np, const char *msg, int len);
  47 void netpoll_print_options(struct netpoll *np);
  48 int netpoll_parse_options(struct netpoll *np, char *opt);
  49 int __netpoll_setup(struct netpoll *np);
  50 int netpoll_setup(struct netpoll *np);
  51 int netpoll_trap(void);
  52 void netpoll_set_trap(int trap);
  53 void __netpoll_cleanup(struct netpoll *np);
  54 void netpoll_cleanup(struct netpoll *np);
  55 int __netpoll_rx(struct sk_buff *skb);
  56 void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb);
  57
  58
  59 #ifdef CONFIG_NETPOLL
  60 static inline bool netpoll_rx(struct sk_buff *skb)
  61 {
  62         struct netpoll_info *npinfo;
  63         unsigned long flags;
  64         bool ret = false;
  65
  66         local_irq_save(flags);
  67         npinfo = rcu_dereference_bh(skb->dev->npinfo);
  68
  69         if (!npinfo || (list_empty(&npinfo->rx_np) && !npinfo->rx_flags))
  70                 goto out;
  71
  72         spin_lock(&npinfo->rx_lock);
  73         /* check rx_flags again with the lock held */
  74         if (npinfo->rx_flags && __netpoll_rx(skb))
  75                 ret = true;
  76         spin_unlock(&npinfo->rx_lock);
  77
  78 out:
  79         local_irq_restore(flags);
  80         return ret;
  81 }
  82
  83 static inline int netpoll_rx_on(struct sk_buff *skb)
  84 {
  85         struct netpoll_info *npinfo = rcu_dereference_bh(skb->dev->npinfo);
  86
  87         return npinfo && (!list_empty(&npinfo->rx_np) || npinfo->rx_flags);
  88 }
  89
  90 static inline int netpoll_receive_skb(struct sk_buff *skb)
  91 {
  92         if (!list_empty(&skb->dev->napi_list))
  93                 return netpoll_rx(skb);
  94         return 0;
  95 }
  96
  97 static inline void *netpoll_poll_lock(struct napi_struct *napi)
  98 {
  99         struct net_device *dev = napi->dev;
 100
 101         if (dev && dev->npinfo) {
 102                 spin_lock(&napi->poll_lock);
 103                 napi->poll_owner = smp_processor_id();
 104                 return napi;
 105         }
 106         return NULL;
 107 }
 108
 109 static inline void netpoll_poll_unlock(void *have)
 110 {
 111         struct napi_struct *napi = have;
 112
 113         if (napi) {
 114                 napi->poll_owner = -1;
 115                 spin_unlock(&napi->poll_lock);
 116         }
 117 }
 118
 119 static inline int netpoll_tx_running(struct net_device *dev)
 120 {
 121         return irqs_disabled();
 122 }
 123
 124 #else
 125 static inline bool netpoll_rx(struct sk_buff *skb)
 126 {
 127         return 0;
 128 }
 129 static inline int netpoll_rx_on(struct sk_buff *skb)
 130 {
 131         return 0;
 132 }
 133 static inline int netpoll_receive_skb(struct sk_buff *skb)
 134 {
 135         return 0;
 136 }
 137 static inline void *netpoll_poll_lock(struct napi_struct *napi)
 138 {
 139         return NULL;
 140 }
 141 static inline void netpoll_poll_unlock(void *have)
 142 {
 143 }
 144 static inline void netpoll_netdev_init(struct net_device *dev)
 145 {
 146 }
 147 static inline int netpoll_tx_running(struct net_device *dev)
 148 {
 149         return 0;
 150 }
 151 #endif
 152
 153 #endif