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         struct netpoll *netpoll;
  41 };
  42
  43 void netpoll_send_udp(struct netpoll *np, const char *msg, int len);
  44 void netpoll_print_options(struct netpoll *np);
  45 int netpoll_parse_options(struct netpoll *np, char *opt);
  46 int __netpoll_setup(struct netpoll *np);
  47 int netpoll_setup(struct netpoll *np);
  48 int netpoll_trap(void);
  49 void netpoll_set_trap(int trap);
  50 void __netpoll_cleanup(struct netpoll *np);
  51 void netpoll_cleanup(struct netpoll *np);
  52 int __netpoll_rx(struct sk_buff *skb);
  53 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
  54                              struct net_device *dev);
  55 static 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
  63 static 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
  81 out:
  82         local_irq_restore(flags);
  83         return ret;
  84 }
  85
  86 static 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
  93 static 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
 100 static 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
 112 static 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
 122 static inline int netpoll_tx_running(struct net_device *dev)
 123 {
 124         return irqs_disabled();
 125 }
 126
 127 #else
 128 static inline bool netpoll_rx(struct sk_buff *skb)
 129 {
 130         return 0;
 131 }
 132 static inline int netpoll_rx_on(struct sk_buff *skb)
 133 {
 134         return 0;
 135 }
 136 static inline int netpoll_receive_skb(struct sk_buff *skb)
 137 {
 138         return 0;
 139 }
 140 static inline void *netpoll_poll_lock(struct napi_struct *napi)
 141 {
 142         return NULL;
 143 }
 144 static inline void netpoll_poll_unlock(void *have)
 145 {
 146 }
 147 static inline void netpoll_netdev_init(struct net_device *dev)
 148 {
 149 }
 150 static inline int netpoll_tx_running(struct net_device *dev)
 151 {
 152         return 0;
 153 }
 154 #endif
 155
 156 #endif