netpoll.h

  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
 17union inet_addr {
 18	__be32		ip;
 19	struct in6_addr	in6;
 20};
 21
 22struct netpoll {
 23	struct net_device *dev;
 24	netdevice_tracker dev_tracker;
 25	/*
 26	 * Either dev_name or dev_mac can be used to specify the local
 27	 * interface - dev_name is used if it is a nonempty string, else
 28	 * dev_mac is used.
 29	 */
 30	char dev_name[IFNAMSIZ];
 31	u8 dev_mac[ETH_ALEN];
 32	const char *name;
 33
 34	union inet_addr local_ip, remote_ip;
 35	bool ipv6;
 36	u16 local_port, remote_port;
 37	u8 remote_mac[ETH_ALEN];
 38	struct sk_buff_head skb_pool;
 39	struct work_struct refill_wq;
 40};
 41
 42#define np_info(np, fmt, ...)				\
 43	pr_info("%s: " fmt, np->name, ##__VA_ARGS__)
 44#define np_err(np, fmt, ...)				\
 45	pr_err("%s: " fmt, np->name, ##__VA_ARGS__)
 46#define np_notice(np, fmt, ...)				\
 47	pr_notice("%s: " fmt, np->name, ##__VA_ARGS__)
 48
 49struct netpoll_info {
 50	refcount_t refcnt;
 51
 52	struct semaphore dev_lock;
 53
 54	struct sk_buff_head txq;
 55
 56	struct delayed_work tx_work;
 57
 58	struct rcu_head rcu;
 59};
 60
 61#ifdef CONFIG_NETPOLL
 62void netpoll_poll_dev(struct net_device *dev);
 63void netpoll_poll_disable(struct net_device *dev);
 64void netpoll_poll_enable(struct net_device *dev);
 65#else
 66static inline void netpoll_poll_disable(struct net_device *dev) { return; }
 67static inline void netpoll_poll_enable(struct net_device *dev) { return; }
 68#endif
 69
 70int netpoll_send_udp(struct netpoll *np, const char *msg, int len);
 71int __netpoll_setup(struct netpoll *np, struct net_device *ndev);
 72int netpoll_setup(struct netpoll *np);
 73void __netpoll_free(struct netpoll *np);
 74void netpoll_cleanup(struct netpoll *np);
 75void do_netpoll_cleanup(struct netpoll *np);
 76netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb);
 77
 78#ifdef CONFIG_NETPOLL
 79static 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
 94static 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
102static inline bool netpoll_tx_running(struct net_device *dev)
103{
104	return irqs_disabled();
105}
106
107#else
108static inline void *netpoll_poll_lock(struct napi_struct *napi)
109{
110	return NULL;
111}
112static inline void netpoll_poll_unlock(void *have)
113{
114}
115static inline bool netpoll_tx_running(struct net_device *dev)
116{
117	return false;
118}
119#endif
120
121#endif