xref: /linux/include/linux/netpoll.h (revision 3fd6c59042dbba50391e30862beac979491145fe)
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 	char dev_name[IFNAMSIZ];
29 	const char *name;
30 
31 	union inet_addr local_ip, remote_ip;
32 	bool ipv6;
33 	u16 local_port, remote_port;
34 	u8 remote_mac[ETH_ALEN];
35 	struct sk_buff_head skb_pool;
36 };
37 
38 struct netpoll_info {
39 	refcount_t refcnt;
40 
41 	struct semaphore dev_lock;
42 
43 	struct sk_buff_head txq;
44 
45 	struct delayed_work tx_work;
46 
47 	struct netpoll *netpoll;
48 	struct rcu_head rcu;
49 };
50 
51 #ifdef CONFIG_NETPOLL
52 void netpoll_poll_dev(struct net_device *dev);
53 void netpoll_poll_disable(struct net_device *dev);
54 void netpoll_poll_enable(struct net_device *dev);
55 #else
netpoll_poll_disable(struct net_device * dev)56 static inline void netpoll_poll_disable(struct net_device *dev) { return; }
netpoll_poll_enable(struct net_device * dev)57 static inline void netpoll_poll_enable(struct net_device *dev) { return; }
58 #endif
59 
60 void netpoll_send_udp(struct netpoll *np, const char *msg, int len);
61 void netpoll_print_options(struct netpoll *np);
62 int netpoll_parse_options(struct netpoll *np, char *opt);
63 int __netpoll_setup(struct netpoll *np, struct net_device *ndev);
64 int netpoll_setup(struct netpoll *np);
65 void __netpoll_cleanup(struct netpoll *np);
66 void __netpoll_free(struct netpoll *np);
67 void netpoll_cleanup(struct netpoll *np);
68 void do_netpoll_cleanup(struct netpoll *np);
69 netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb);
70 
71 #ifdef CONFIG_NETPOLL
netpoll_poll_lock(struct napi_struct * napi)72 static inline void *netpoll_poll_lock(struct napi_struct *napi)
73 {
74 	struct net_device *dev = napi->dev;
75 
76 	if (dev && rcu_access_pointer(dev->npinfo)) {
77 		int owner = smp_processor_id();
78 
79 		while (cmpxchg(&napi->poll_owner, -1, owner) != -1)
80 			cpu_relax();
81 
82 		return napi;
83 	}
84 	return NULL;
85 }
86 
netpoll_poll_unlock(void * have)87 static inline void netpoll_poll_unlock(void *have)
88 {
89 	struct napi_struct *napi = have;
90 
91 	if (napi)
92 		smp_store_release(&napi->poll_owner, -1);
93 }
94 
netpoll_tx_running(struct net_device * dev)95 static inline bool netpoll_tx_running(struct net_device *dev)
96 {
97 	return irqs_disabled();
98 }
99 
100 #else
netpoll_poll_lock(struct napi_struct * napi)101 static inline void *netpoll_poll_lock(struct napi_struct *napi)
102 {
103 	return NULL;
104 }
netpoll_poll_unlock(void * have)105 static inline void netpoll_poll_unlock(void *have)
106 {
107 }
netpoll_tx_running(struct net_device * dev)108 static inline bool netpoll_tx_running(struct net_device *dev)
109 {
110 	return false;
111 }
112 #endif
113 
114 #endif
115