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_skb_hook)(struct netpoll *np, int source, struct sk_buff *skb,
  28                             int offset, int len);
  29
  30         union inet_addr local_ip, remote_ip;
  31         bool ipv6;
  32         u16 local_port, remote_port;
  33         u8 remote_mac[ETH_ALEN];
  34
  35         struct list_head rx; /* rx_np list element */
  36         struct work_struct cleanup_work;
  37 };
  38
  39 struct netpoll_info {
  40         atomic_t refcnt;
  41
  42         spinlock_t rx_lock;
  43         struct semaphore dev_lock;
  44         struct list_head rx_np; /* netpolls that registered an rx_skb_hook */
  45
  46         struct sk_buff_head neigh_tx; /* list of neigh requests to reply to */
  47         struct sk_buff_head txq;
  48
  49         struct delayed_work tx_work;
  50
  51         struct netpoll *netpoll;
  52         struct rcu_head rcu;
  53 };
  54
  55 #ifdef CONFIG_NETPOLL
  56 extern void netpoll_rx_disable(struct net_device *dev);
  57 extern void netpoll_rx_enable(struct net_device *dev);
  58 #else
  59 static inline void netpoll_rx_disable(struct net_device *dev) { return; }
  60 static inline void netpoll_rx_enable(struct net_device *dev) { return; }
  61 #endif
  62
  63 void netpoll_send_udp(struct netpoll *np, const char *msg, int len);
  64 void netpoll_print_options(struct netpoll *np);
  65 int netpoll_parse_options(struct netpoll *np, char *opt);
  66 int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp);
  67 int netpoll_setup(struct netpoll *np);
  68 void __netpoll_cleanup(struct netpoll *np);
  69 void __netpoll_free_async(struct netpoll *np);
  70 void netpoll_cleanup(struct netpoll *np);
  71 int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo);
  72 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
  73                              struct net_device *dev);
  74 static inline void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
  75 {
  76         unsigned long flags;
  77         local_irq_save(flags);
  78         netpoll_send_skb_on_dev(np, skb, np->dev);
  79         local_irq_restore(flags);
  80 }
  81
  82 #ifdef CONFIG_NETPOLL_TRAP
  83 int netpoll_trap(void);
  84 void netpoll_set_trap(int trap);
  85 static inline bool netpoll_rx_processing(struct netpoll_info *npinfo)
  86 {
  87         return !list_empty(&npinfo->rx_np);
  88 }
  89 #else
  90 static inline int netpoll_trap(void)
  91 {
  92         return 0;
  93 }
  94 static inline void netpoll_set_trap(int trap)
  95 {
  96 }
  97 static inline bool netpoll_rx_processing(struct netpoll_info *npinfo)
  98 {
  99         return false;
 100 }
 101 #endif
 102
 103 #ifdef CONFIG_NETPOLL
 104 static inline bool netpoll_rx_on(struct sk_buff *skb)
 105 {
 106         struct netpoll_info *npinfo = rcu_dereference_bh(skb->dev->npinfo);
 107
 108         return npinfo && netpoll_rx_processing(npinfo);
 109 }
 110
 111 static inline bool netpoll_rx(struct sk_buff *skb)
 112 {
 113         struct netpoll_info *npinfo;
 114         unsigned long flags;
 115         bool ret = false;
 116
 117         local_irq_save(flags);
 118
 119         if (!netpoll_rx_on(skb))
 120                 goto out;
 121
 122         npinfo = rcu_dereference_bh(skb->dev->npinfo);
 123         spin_lock(&npinfo->rx_lock);
 124         /* check rx_processing again with the lock held */
 125         if (netpoll_rx_processing(npinfo) && __netpoll_rx(skb, npinfo))
 126                 ret = true;
 127         spin_unlock(&npinfo->rx_lock);
 128
 129 out:
 130         local_irq_restore(flags);
 131         return ret;
 132 }
 133
 134 static inline int netpoll_receive_skb(struct sk_buff *skb)
 135 {
 136         if (!list_empty(&skb->dev->napi_list))
 137                 return netpoll_rx(skb);
 138         return 0;
 139 }
 140
 141 static inline void *netpoll_poll_lock(struct napi_struct *napi)
 142 {
 143         struct net_device *dev = napi->dev;
 144
 145         if (dev && dev->npinfo) {
 146                 spin_lock(&napi->poll_lock);
 147                 napi->poll_owner = smp_processor_id();
 148                 return napi;
 149         }
 150         return NULL;
 151 }
 152
 153 static inline void netpoll_poll_unlock(void *have)
 154 {
 155         struct napi_struct *napi = have;
 156
 157         if (napi) {
 158                 napi->poll_owner = -1;
 159                 spin_unlock(&napi->poll_lock);
 160         }
 161 }
 162
 163 static inline bool netpoll_tx_running(struct net_device *dev)
 164 {
 165         return irqs_disabled();
 166 }
 167
 168 #else
 169 static inline bool netpoll_rx(struct sk_buff *skb)
 170 {
 171         return false;
 172 }
 173 static inline bool netpoll_rx_on(struct sk_buff *skb)
 174 {
 175         return false;
 176 }
 177 static inline int netpoll_receive_skb(struct sk_buff *skb)
 178 {
 179         return 0;
 180 }
 181 static inline void *netpoll_poll_lock(struct napi_struct *napi)
 182 {
 183         return NULL;
 184 }
 185 static inline void netpoll_poll_unlock(void *have)
 186 {
 187 }
 188 static inline void netpoll_netdev_init(struct net_device *dev)
 189 {
 190 }
 191 static inline bool netpoll_tx_running(struct net_device *dev)
 192 {
 193         return false;
 194 }
 195 #endif
 196
 197 #endif