LXR linux/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
  15struct 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
  28struct 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        struct netpoll *netpoll;
  41};
  42
  43void netpoll_send_udp(struct netpoll *np, const char *msg, int len);
  44void netpoll_print_options(struct netpoll *np);
  45int netpoll_parse_options(struct netpoll *np, char *opt);
  46int __netpoll_setup(struct netpoll *np);
  47int netpoll_setup(struct netpoll *np);
  48int netpoll_trap(void);
  49void netpoll_set_trap(int trap);
  50void __netpoll_cleanup(struct netpoll *np);
  51void netpoll_cleanup(struct netpoll *np);
  52int __netpoll_rx(struct sk_buff *skb);
  53void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
  54                             struct net_device *dev);
  55static inline void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
  56{
  57        netpoll_send_skb_on_dev(np, skb, np->dev);
  58}
  59
  60
  61
  62#ifdef CONFIG_NETPOLL
  63static inline bool netpoll_rx(struct sk_buff *skb)
  64{
  65        struct netpoll_info *npinfo;
  66        unsigned long flags;
  67        bool ret = false;
  68
  69        local_irq_save(flags);
  70        npinfo = rcu_dereference_bh(skb->dev->npinfo);
  71
  72        if (!npinfo || (list_empty(&npinfo->rx_np) && !npinfo->rx_flags))
  73                goto out;
  74
  75        spin_lock(&npinfo->rx_lock);
  76        /* check rx_flags again with the lock held */
  77        if (npinfo->rx_flags && __netpoll_rx(skb))
  78                ret = true;
  79        spin_unlock(&npinfo->rx_lock);
  80
  81out:
  82        local_irq_restore(flags);
  83        return ret;
  84}
  85
  86static inline int netpoll_rx_on(struct sk_buff *skb)
  87{
  88        struct netpoll_info *npinfo = rcu_dereference_bh(skb->dev->npinfo);
  89
  90        return npinfo && (!list_empty(&npinfo->rx_np) || npinfo->rx_flags);
  91}
  92
  93static inline int netpoll_receive_skb(struct sk_buff *skb)
  94{
  95        if (!list_empty(&skb->dev->napi_list))
  96                return netpoll_rx(skb);
  97        return 0;
  98}
  99
 100static inline void *netpoll_poll_lock(struct napi_struct *napi)
 101{
 102        struct net_device *dev = napi->dev;
 103
 104        if (dev && dev->npinfo) {
 105                spin_lock(&napi->poll_lock);
 106                napi->poll_owner = smp_processor_id();
 107                return napi;
 108        }
 109        return NULL;
 110}
 111
 112static inline void netpoll_poll_unlock(void *have)
 113{
 114        struct napi_struct *napi = have;
 115
 116        if (napi) {
 117                napi->poll_owner = -1;
 118                spin_unlock(&napi->poll_lock);
 119        }
 120}
 121
 122static inline int netpoll_tx_running(struct net_device *dev)
 123{
 124        return irqs_disabled();
 125}
 126
 127#else
 128static inline bool netpoll_rx(struct sk_buff *skb)
 129{
 130        return 0;
 131}
 132static inline int netpoll_rx_on(struct sk_buff *skb)
 133{
 134        return 0;
 135}
 136static inline int netpoll_receive_skb(struct sk_buff *skb)
 137{
 138        return 0;
 139}
 140static inline void *netpoll_poll_lock(struct napi_struct *napi)
 141{
 142        return NULL;
 143}
 144static inline void netpoll_poll_unlock(void *have)
 145{
 146}
 147static inline void netpoll_netdev_init(struct net_device *dev)
 148{
 149}
 150static inline int netpoll_tx_running(struct net_device *dev)
 151{
 152        return 0;
 153}
 154#endif
 155
 156#endif
 157