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
15struct 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	u32 local_ip, remote_ip;
22	u16 local_port, remote_port;
23 	u8 local_mac[ETH_ALEN], remote_mac[ETH_ALEN];
24};
25
26struct netpoll_info {
27	atomic_t refcnt;
28	spinlock_t poll_lock;
29	int poll_owner;
30	int rx_flags;
31	spinlock_t rx_lock;
32	struct netpoll *rx_np; /* netpoll that registered an rx_hook */
33	struct sk_buff_head arp_tx; /* list of arp requests to reply to */
34	struct sk_buff_head txq;
35	struct delayed_work tx_work;
36};
37
38void netpoll_poll(struct netpoll *np);
39void netpoll_send_udp(struct netpoll *np, const char *msg, int len);
40int netpoll_parse_options(struct netpoll *np, char *opt);
41int netpoll_setup(struct netpoll *np);
42int netpoll_trap(void);
43void netpoll_set_trap(int trap);
44void netpoll_cleanup(struct netpoll *np);
45int __netpoll_rx(struct sk_buff *skb);
46
47
48#ifdef CONFIG_NETPOLL
49static inline int netpoll_rx(struct sk_buff *skb)
50{
51	struct netpoll_info *npinfo = skb->dev->npinfo;
52	unsigned long flags;
53	int ret = 0;
54
55	if (!npinfo || (!npinfo->rx_np && !npinfo->rx_flags))
56		return 0;
57
58	spin_lock_irqsave(&npinfo->rx_lock, flags);
59	/* check rx_flags again with the lock held */
60	if (npinfo->rx_flags && __netpoll_rx(skb))
61		ret = 1;
62	spin_unlock_irqrestore(&npinfo->rx_lock, flags);
63
64	return ret;
65}
66
67static inline void *netpoll_poll_lock(struct net_device *dev)
68{
69	rcu_read_lock(); /* deal with race on ->npinfo */
70	if (dev->npinfo) {
71		spin_lock(&dev->npinfo->poll_lock);
72		dev->npinfo->poll_owner = smp_processor_id();
73		return dev->npinfo;
74	}
75	return NULL;
76}
77
78static inline void netpoll_poll_unlock(void *have)
79{
80	struct netpoll_info *npi = have;
81
82	if (npi) {
83		npi->poll_owner = -1;
84		spin_unlock(&npi->poll_lock);
85	}
86	rcu_read_unlock();
87}
88
89#else
90#define netpoll_rx(a) 0
91#define netpoll_poll_lock(a) NULL
92#define netpoll_poll_unlock(a)
93#endif
94
95#endif
96