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_trap(void);
  51 void netpoll_set_trap(int trap);
  52 void netpoll_cleanup(struct netpoll *np);
  53 int __netpoll_rx(struct sk_buff *skb);
  54 void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb);
  55
  56
  57 #ifdef CONFIG_NETPOLL
  58 static inline bool netpoll_rx(struct sk_buff *skb)
  59 {
  60         struct netpoll_info *npinfo = skb->dev->npinfo;
  61         unsigned long flags;
  62         bool ret = false;
  63
  64         if (!npinfo || (list_empty(&npinfo->rx_np) && !npinfo->rx_flags))
  65                 return false;
  66
  67         spin_lock_irqsave(&npinfo->rx_lock, flags);
  68         /* check rx_flags again with the lock held */
  69         if (npinfo->rx_flags && __netpoll_rx(skb))
  70                 ret = true;
  71         spin_unlock_irqrestore(&npinfo->rx_lock, flags);
  72
  73         return ret;
  74 }
  75
  76 static inline int netpoll_rx_on(struct sk_buff *skb)
  77 {
  78         struct netpoll_info *npinfo = skb->dev->npinfo;
  79
  80         return npinfo && (!list_empty(&npinfo->rx_np) || npinfo->rx_flags);
  81 }
  82
  83 static inline int netpoll_receive_skb(struct sk_buff *skb)
  84 {
  85         if (!list_empty(&skb->dev->napi_list))
  86                 return netpoll_rx(skb);
  87         return 0;
  88 }
  89
  90 static inline void *netpoll_poll_lock(struct napi_struct *napi)
  91 {
  92         struct net_device *dev = napi->dev;
  93
  94         rcu_read_lock(); /* deal with race on ->npinfo */
  95         if (dev && dev->npinfo) {
  96                 spin_lock(&napi->poll_lock);
  97                 napi->poll_owner = smp_processor_id();
  98                 return napi;
  99         }
 100         return NULL;
 101 }
 102
 103 static inline void netpoll_poll_unlock(void *have)
 104 {
 105         struct napi_struct *napi = have;
 106
 107         if (napi) {
 108                 napi->poll_owner = -1;
 109                 spin_unlock(&napi->poll_lock);
 110         }
 111         rcu_read_unlock();
 112 }
 113
 114 #else
 115 static inline int netpoll_rx(struct sk_buff *skb)
 116 {
 117         return 0;
 118 }
 119 static inline int netpoll_rx_on(struct sk_buff *skb)
 120 {
 121         return 0;
 122 }
 123 static inline int netpoll_receive_skb(struct sk_buff *skb)
 124 {
 125         return 0;
 126 }
 127 static inline void *netpoll_poll_lock(struct napi_struct *napi)
 128 {
 129         return NULL;
 130 }
 131 static inline void netpoll_poll_unlock(void *have)
 132 {
 133 }
 134 static inline void netpoll_netdev_init(struct net_device *dev)
 135 {
 136 }
 137 #endif
 138
 139 #endif