xref: /linux-6.15/include/linux/netpoll.h (revision c0a9290e)
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 	u32 local_ip, remote_ip;
22 	u16 local_port, remote_port;
23 	u8 remote_mac[ETH_ALEN];
24 };
25 
26 struct netpoll_info {
27 	atomic_t refcnt;
28 	spinlock_t rx_lock;
29 	struct netpoll *rx_np; /* netpoll that registered an rx_hook */
30 	struct sk_buff_head arp_tx; /* list of arp requests to reply to */
31 	struct sk_buff_head txq;
32 	struct delayed_work tx_work;
33 };
34 
35 void netpoll_poll(struct netpoll *np);
36 void netpoll_send_udp(struct netpoll *np, const char *msg, int len);
37 void netpoll_print_options(struct netpoll *np);
38 int netpoll_parse_options(struct netpoll *np, char *opt);
39 int netpoll_setup(struct netpoll *np);
40 int netpoll_trap(void);
41 void netpoll_set_trap(int trap);
42 void netpoll_cleanup(struct netpoll *np);
43 int __netpoll_rx(struct sk_buff *skb);
44 
45 
46 #ifdef CONFIG_NETPOLL
47 static inline int netpoll_rx(struct sk_buff *skb)
48 {
49 	struct netpoll_info *npinfo = skb->dev->npinfo;
50 	unsigned long flags;
51 	int ret = 0;
52 
53 	if (!npinfo || !npinfo->rx_np)
54 		return 0;
55 
56 	spin_lock_irqsave(&npinfo->rx_lock, flags);
57 	/* check rx_np again with the lock held */
58 	if (npinfo->rx_np && __netpoll_rx(skb))
59 		ret = 1;
60 	spin_unlock_irqrestore(&npinfo->rx_lock, flags);
61 
62 	return ret;
63 }
64 
65 static inline int netpoll_receive_skb(struct sk_buff *skb)
66 {
67 	if (!list_empty(&skb->dev->napi_list))
68 		return netpoll_rx(skb);
69 	return 0;
70 }
71 
72 static inline void *netpoll_poll_lock(struct napi_struct *napi)
73 {
74 	struct net_device *dev = napi->dev;
75 
76 	rcu_read_lock(); /* deal with race on ->npinfo */
77 	if (dev && dev->npinfo) {
78 		spin_lock(&napi->poll_lock);
79 		napi->poll_owner = smp_processor_id();
80 		return napi;
81 	}
82 	return NULL;
83 }
84 
85 static inline void netpoll_poll_unlock(void *have)
86 {
87 	struct napi_struct *napi = have;
88 
89 	if (napi) {
90 		napi->poll_owner = -1;
91 		spin_unlock(&napi->poll_lock);
92 	}
93 	rcu_read_unlock();
94 }
95 
96 static inline void netpoll_netdev_init(struct net_device *dev)
97 {
98 	INIT_LIST_HEAD(&dev->napi_list);
99 }
100 
101 #else
102 static inline int netpoll_rx(struct sk_buff *skb)
103 {
104 	return 0;
105 }
106 static inline int netpoll_receive_skb(struct sk_buff *skb)
107 {
108 	return 0;
109 }
110 static inline void *netpoll_poll_lock(struct napi_struct *napi)
111 {
112 	return NULL;
113 }
114 static inline void netpoll_poll_unlock(void *have)
115 {
116 }
117 static inline void netpoll_netdev_init(struct net_device *dev)
118 {
119 }
120 #endif
121 
122 #endif
123