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