xref: /linux/include/linux/netpoll.h (revision 1a9239bb4253f9076b5b4b2a1a4e8d7defd77a95)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Common code for low-level network console, dump, and debugger code
4  *
5  * Derived from netconsole, kgdb-over-ethernet, and netdump patches
6  */
7 
8 #ifndef _LINUX_NETPOLL_H
9 #define _LINUX_NETPOLL_H
10 
11 #include <linux/netdevice.h>
12 #include <linux/interrupt.h>
13 #include <linux/rcupdate.h>
14 #include <linux/list.h>
15 #include <linux/refcount.h>
16 
17 union inet_addr {
18 	__u32		all[4];
19 	__be32		ip;
20 	__be32		ip6[4];
21 	struct in_addr	in;
22 	struct in6_addr	in6;
23 };
24 
25 struct netpoll {
26 	struct net_device *dev;
27 	netdevice_tracker dev_tracker;
28 	/*
29 	 * Either dev_name or dev_mac can be used to specify the local
30 	 * interface - dev_name is used if it is a nonempty string, else
31 	 * dev_mac is used.
32 	 */
33 	char dev_name[IFNAMSIZ];
34 	u8 dev_mac[ETH_ALEN];
35 	const char *name;
36 
37 	union inet_addr local_ip, remote_ip;
38 	bool ipv6;
39 	u16 local_port, remote_port;
40 	u8 remote_mac[ETH_ALEN];
41 	struct sk_buff_head skb_pool;
42 	struct work_struct refill_wq;
43 };
44 
45 struct netpoll_info {
46 	refcount_t refcnt;
47 
48 	struct semaphore dev_lock;
49 
50 	struct sk_buff_head txq;
51 
52 	struct delayed_work tx_work;
53 
54 	struct netpoll *netpoll;
55 	struct rcu_head rcu;
56 };
57 
58 #ifdef CONFIG_NETPOLL
59 void netpoll_poll_dev(struct net_device *dev);
60 void netpoll_poll_disable(struct net_device *dev);
61 void netpoll_poll_enable(struct net_device *dev);
62 #else
netpoll_poll_disable(struct net_device * dev)63 static inline void netpoll_poll_disable(struct net_device *dev) { return; }
netpoll_poll_enable(struct net_device * dev)64 static inline void netpoll_poll_enable(struct net_device *dev) { return; }
65 #endif
66 
67 int netpoll_send_udp(struct netpoll *np, const char *msg, int len);
68 void netpoll_print_options(struct netpoll *np);
69 int netpoll_parse_options(struct netpoll *np, char *opt);
70 int __netpoll_setup(struct netpoll *np, struct net_device *ndev);
71 int netpoll_setup(struct netpoll *np);
72 void __netpoll_cleanup(struct netpoll *np);
73 void __netpoll_free(struct netpoll *np);
74 void netpoll_cleanup(struct netpoll *np);
75 void do_netpoll_cleanup(struct netpoll *np);
76 netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb);
77 
78 #ifdef CONFIG_NETPOLL
netpoll_poll_lock(struct napi_struct * napi)79 static inline void *netpoll_poll_lock(struct napi_struct *napi)
80 {
81 	struct net_device *dev = napi->dev;
82 
83 	if (dev && rcu_access_pointer(dev->npinfo)) {
84 		int owner = smp_processor_id();
85 
86 		while (cmpxchg(&napi->poll_owner, -1, owner) != -1)
87 			cpu_relax();
88 
89 		return napi;
90 	}
91 	return NULL;
92 }
93 
netpoll_poll_unlock(void * have)94 static inline void netpoll_poll_unlock(void *have)
95 {
96 	struct napi_struct *napi = have;
97 
98 	if (napi)
99 		smp_store_release(&napi->poll_owner, -1);
100 }
101 
netpoll_tx_running(struct net_device * dev)102 static inline bool netpoll_tx_running(struct net_device *dev)
103 {
104 	return irqs_disabled();
105 }
106 
107 #else
netpoll_poll_lock(struct napi_struct * napi)108 static inline void *netpoll_poll_lock(struct napi_struct *napi)
109 {
110 	return NULL;
111 }
netpoll_poll_unlock(void * have)112 static inline void netpoll_poll_unlock(void *have)
113 {
114 }
netpoll_tx_running(struct net_device * dev)115 static inline bool netpoll_tx_running(struct net_device *dev)
116 {
117 	return false;
118 }
119 #endif
120 
121 #endif
122