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         struct rcu_head rcu;
  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         struct rcu_head rcu;
  43 };
  44
  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, struct net_device *ndev, gfp_t gfp);
  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_free_rcu(struct netpoll *np);
  54 void netpoll_cleanup(struct netpoll *np);
  55 int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo);
  56 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
  57                              struct net_device *dev);
  58 static inline void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
  59 {
  60         unsigned long flags;
  61         local_irq_save(flags);
  62         netpoll_send_skb_on_dev(np, skb, np->dev);
  63         local_irq_restore(flags);
  64 }
  65
  66
  67
  68 #ifdef CONFIG_NETPOLL
  69 static inline bool netpoll_rx_on(struct sk_buff *skb)
  70 {
  71         struct netpoll_info *npinfo = rcu_dereference_bh(skb->dev->npinfo);
  72
  73         return npinfo && (!list_empty(&npinfo->rx_np) || npinfo->rx_flags);
  74 }
  75
  76 static inline bool netpoll_rx(struct sk_buff *skb)
  77 {
  78         struct netpoll_info *npinfo;
  79         unsigned long flags;
  80         bool ret = false;
  81
  82         local_irq_save(flags);
  83
  84         if (!netpoll_rx_on(skb))
  85                 goto out;
  86
  87         npinfo = rcu_dereference_bh(skb->dev->npinfo);
  88         spin_lock(&npinfo->rx_lock);
  89         /* check rx_flags again with the lock held */
  90         if (npinfo->rx_flags && __netpoll_rx(skb, npinfo))
  91                 ret = true;
  92         spin_unlock(&npinfo->rx_lock);
  93
  94 out:
  95         local_irq_restore(flags);
  96         return ret;
  97 }
  98
  99 static inline int netpoll_receive_skb(struct sk_buff *skb)
 100 {
 101         if (!list_empty(&skb->dev->napi_list))
 102                 return netpoll_rx(skb);
 103         return 0;
 104 }
 105
 106 static inline void *netpoll_poll_lock(struct napi_struct *napi)
 107 {
 108         struct net_device *dev = napi->dev;
 109
 110         if (dev && dev->npinfo) {
 111                 spin_lock(&napi->poll_lock);
 112                 napi->poll_owner = smp_processor_id();
 113                 return napi;
 114         }
 115         return NULL;
 116 }
 117
 118 static inline void netpoll_poll_unlock(void *have)
 119 {
 120         struct napi_struct *napi = have;
 121
 122         if (napi) {
 123                 napi->poll_owner = -1;
 124                 spin_unlock(&napi->poll_lock);
 125         }
 126 }
 127
 128 static inline bool netpoll_tx_running(struct net_device *dev)
 129 {
 130         return irqs_disabled();
 131 }
 132
 133 #else
 134 static inline bool netpoll_rx(struct sk_buff *skb)
 135 {
 136         return false;
 137 }
 138 static inline bool netpoll_rx_on(struct sk_buff *skb)
 139 {
 140         return false;
 141 }
 142 static inline int netpoll_receive_skb(struct sk_buff *skb)
 143 {
 144         return 0;
 145 }
 146 static inline void *netpoll_poll_lock(struct napi_struct *napi)
 147 {
 148         return NULL;
 149 }
 150 static inline void netpoll_poll_unlock(void *have)
 151 {
 152 }
 153 static inline void netpoll_netdev_init(struct net_device *dev)
 154 {
 155 }
 156 static inline bool netpoll_tx_running(struct net_device *dev)
 157 {
 158         return false;
 159 }
 160 #endif
 161
 162 #endif