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         unsigned long rx_flags;
  43         spinlock_t rx_lock;
  44         struct semaphore dev_lock;
  45         struct list_head rx_np; /* netpolls that registered an rx_skb_hook */
  46
  47         struct sk_buff_head neigh_tx; /* list of neigh requests to reply to */
  48         struct sk_buff_head txq;
  49
  50         struct delayed_work tx_work;
  51
  52         struct netpoll *netpoll;
  53         struct rcu_head rcu;
  54 };
  55
  56 #ifdef CONFIG_NETPOLL
  57 extern void netpoll_rx_disable(struct net_device *dev);
  58 extern void netpoll_rx_enable(struct net_device *dev);
  59 #else
  60 static inline void netpoll_rx_disable(struct net_device *dev) { return; }
  61 static inline void netpoll_rx_enable(struct net_device *dev) { return; }
  62 #endif
  63
  64 void netpoll_send_udp(struct netpoll *np, const char *msg, int len);
  65 void netpoll_print_options(struct netpoll *np);
  66 int netpoll_parse_options(struct netpoll *np, char *opt);
  67 int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp);
  68 int netpoll_setup(struct netpoll *np);
  69 int netpoll_trap(void);
  70 void netpoll_set_trap(int trap);
  71 void __netpoll_cleanup(struct netpoll *np);
  72 void __netpoll_free_async(struct netpoll *np);
  73 void netpoll_cleanup(struct netpoll *np);
  74 int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo);
  75 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
  76                              struct net_device *dev);
  77 static inline void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
  78 {
  79         unsigned long flags;
  80         local_irq_save(flags);
  81         netpoll_send_skb_on_dev(np, skb, np->dev);
  82         local_irq_restore(flags);
  83 }
  84
  85
  86
  87 #ifdef CONFIG_NETPOLL
  88 static inline bool 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 bool netpoll_rx(struct sk_buff *skb)
  96 {
  97         struct netpoll_info *npinfo;
  98         unsigned long flags;
  99         bool ret = false;
 100
 101         local_irq_save(flags);
 102
 103         if (!netpoll_rx_on(skb))
 104                 goto out;
 105
 106         npinfo = rcu_dereference_bh(skb->dev->npinfo);
 107         spin_lock(&npinfo->rx_lock);
 108         /* check rx_flags again with the lock held */
 109         if (npinfo->rx_flags && __netpoll_rx(skb, npinfo))
 110                 ret = true;
 111         spin_unlock(&npinfo->rx_lock);
 112
 113 out:
 114         local_irq_restore(flags);
 115         return ret;
 116 }
 117
 118 static inline int netpoll_receive_skb(struct sk_buff *skb)
 119 {
 120         if (!list_empty(&skb->dev->napi_list))
 121                 return netpoll_rx(skb);
 122         return 0;
 123 }
 124
 125 static inline void *netpoll_poll_lock(struct napi_struct *napi)
 126 {
 127         struct net_device *dev = napi->dev;
 128
 129         if (dev && dev->npinfo) {
 130                 spin_lock(&napi->poll_lock);
 131                 napi->poll_owner = smp_processor_id();
 132                 return napi;
 133         }
 134         return NULL;
 135 }
 136
 137 static inline void netpoll_poll_unlock(void *have)
 138 {
 139         struct napi_struct *napi = have;
 140
 141         if (napi) {
 142                 napi->poll_owner = -1;
 143                 spin_unlock(&napi->poll_lock);
 144         }
 145 }
 146
 147 static inline bool netpoll_tx_running(struct net_device *dev)
 148 {
 149         return irqs_disabled();
 150 }
 151
 152 #else
 153 static inline bool netpoll_rx(struct sk_buff *skb)
 154 {
 155         return false;
 156 }
 157 static inline bool netpoll_rx_on(struct sk_buff *skb)
 158 {
 159         return false;
 160 }
 161 static inline int netpoll_receive_skb(struct sk_buff *skb)
 162 {
 163         return 0;
 164 }
 165 static inline void *netpoll_poll_lock(struct napi_struct *napi)
 166 {
 167         return NULL;
 168 }
 169 static inline void netpoll_poll_unlock(void *have)
 170 {
 171 }
 172 static inline void netpoll_netdev_init(struct net_device *dev)
 173 {
 174 }
 175 static inline bool netpoll_tx_running(struct net_device *dev)
 176 {
 177         return false;
 178 }
 179 #endif
 180
 181 #endif