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 union inet_addr {
  16         __u32           all[4];
  17         __be32          ip;
  18         __be32          ip6[4];
  19         struct in_addr  in;
  20         struct in6_addr in6;
  21 };
  22
  23 struct netpoll {
  24         struct net_device *dev;
  25         char dev_name[IFNAMSIZ];
  26         const char *name;
  27         void (*rx_hook)(struct netpoll *, int, char *, int);
  28
  29         union inet_addr local_ip, remote_ip;
  30         bool ipv6;
  31         u16 local_port, remote_port;
  32         u8 remote_mac[ETH_ALEN];
  33
  34         struct list_head rx; /* rx_np list element */
  35         struct rcu_head rcu;
  36 };
  37
  38 struct netpoll_info {
  39         atomic_t refcnt;
  40
  41         int rx_flags;
  42         spinlock_t rx_lock;
  43         struct list_head rx_np; /* netpolls that registered an rx_hook */
  44
  45         struct sk_buff_head neigh_tx; /* list of neigh requests to reply to */
  46         struct sk_buff_head txq;
  47
  48         struct delayed_work tx_work;
  49
  50         struct netpoll *netpoll;
  51         struct rcu_head rcu;
  52 };
  53
  54 void netpoll_send_udp(struct netpoll *np, const char *msg, int len);
  55 void netpoll_print_options(struct netpoll *np);
  56 int netpoll_parse_options(struct netpoll *np, char *opt);
  57 int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp);
  58 int netpoll_setup(struct netpoll *np);
  59 int netpoll_trap(void);
  60 void netpoll_set_trap(int trap);
  61 void __netpoll_cleanup(struct netpoll *np);
  62 void __netpoll_free_rcu(struct netpoll *np);
  63 void netpoll_cleanup(struct netpoll *np);
  64 int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo);
  65 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
  66                              struct net_device *dev);
  67 static inline void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
  68 {
  69         unsigned long flags;
  70         local_irq_save(flags);
  71         netpoll_send_skb_on_dev(np, skb, np->dev);
  72         local_irq_restore(flags);
  73 }
  74
  75
  76
  77 #ifdef CONFIG_NETPOLL
  78 static inline bool netpoll_rx_on(struct sk_buff *skb)
  79 {
  80         struct netpoll_info *npinfo = rcu_dereference_bh(skb->dev->npinfo);
  81
  82         return npinfo && (!list_empty(&npinfo->rx_np) || npinfo->rx_flags);
  83 }
  84
  85 static inline bool netpoll_rx(struct sk_buff *skb)
  86 {
  87         struct netpoll_info *npinfo;
  88         unsigned long flags;
  89         bool ret = false;
  90
  91         local_irq_save(flags);
  92
  93         if (!netpoll_rx_on(skb))
  94                 goto out;
  95
  96         npinfo = rcu_dereference_bh(skb->dev->npinfo);
  97         spin_lock(&npinfo->rx_lock);
  98         /* check rx_flags again with the lock held */
  99         if (npinfo->rx_flags && __netpoll_rx(skb, npinfo))
 100                 ret = true;
 101         spin_unlock(&npinfo->rx_lock);
 102
 103 out:
 104         local_irq_restore(flags);
 105         return ret;
 106 }
 107
 108 static inline int netpoll_receive_skb(struct sk_buff *skb)
 109 {
 110         if (!list_empty(&skb->dev->napi_list))
 111                 return netpoll_rx(skb);
 112         return 0;
 113 }
 114
 115 static inline void *netpoll_poll_lock(struct napi_struct *napi)
 116 {
 117         struct net_device *dev = napi->dev;
 118
 119         if (dev && dev->npinfo) {
 120                 spin_lock(&napi->poll_lock);
 121                 napi->poll_owner = smp_processor_id();
 122                 return napi;
 123         }
 124         return NULL;
 125 }
 126
 127 static inline void netpoll_poll_unlock(void *have)
 128 {
 129         struct napi_struct *napi = have;
 130
 131         if (napi) {
 132                 napi->poll_owner = -1;
 133                 spin_unlock(&napi->poll_lock);
 134         }
 135 }
 136
 137 static inline bool netpoll_tx_running(struct net_device *dev)
 138 {
 139         return irqs_disabled();
 140 }
 141
 142 #else
 143 static inline bool netpoll_rx(struct sk_buff *skb)
 144 {
 145         return false;
 146 }
 147 static inline bool netpoll_rx_on(struct sk_buff *skb)
 148 {
 149         return false;
 150 }
 151 static inline int netpoll_receive_skb(struct sk_buff *skb)
 152 {
 153         return 0;
 154 }
 155 static inline void *netpoll_poll_lock(struct napi_struct *napi)
 156 {
 157         return NULL;
 158 }
 159 static inline void netpoll_poll_unlock(void *have)
 160 {
 161 }
 162 static inline void netpoll_netdev_init(struct net_device *dev)
 163 {
 164 }
 165 static inline bool netpoll_tx_running(struct net_device *dev)
 166 {
 167         return false;
 168 }
 169 #endif
 170
 171 #endif