/*
 * Common code for low-level network console, dump, and debugger code
 *
 * Derived from netconsole, kgdb-over-ethernet, and netdump patches
 */

#ifndef _LINUX_NETPOLL_H
#define _LINUX_NETPOLL_H

#include <linux/netdevice.h>
#include <linux/interrupt.h>
#include <linux/rcupdate.h>
#include <linux/list.h>

struct netpoll;

struct netpoll {
	struct net_device *dev;
	char dev_name[16], *name;
	void (*rx_hook)(struct netpoll *, int, char *, int);
	void (*drop)(struct sk_buff *skb);
	u32 local_ip, remote_ip;
	u16 local_port, remote_port;
	unsigned char local_mac[6], remote_mac[6];
#ifndef __GENKSYMS__
	struct net_device *real_dev;
#endif
};

struct netpoll_info {
	spinlock_t poll_lock;
	int poll_owner;
	int tries;
	int rx_flags;
	spinlock_t rx_lock;
	struct netpoll *rx_np; /* netpoll that registered an rx_hook */
	struct sk_buff_head arp_tx; /* list of arp requests to reply to */
#ifndef __GENKSYMS__
	struct netpoll *netpoll;
	struct rcu_head rcu;
#endif
};

void netpoll_poll_dev (struct net_device *dev);
void netpoll_poll(struct netpoll *np);
void netpoll_send_udp(struct netpoll *np, const char *msg, int len);
int netpoll_parse_options(struct netpoll *np, char *opt);
int netpoll_setup(struct netpoll *np);
int netpoll_trap(void);
void netpoll_set_trap(int trap);
void netpoll_cleanup(struct netpoll *np);
int __netpoll_rx(struct sk_buff *skb);
void netpoll_queue(struct sk_buff *skb);
void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb);
void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
			     struct net_device *dev);

#ifdef CONFIG_NETPOLL
static inline int netpoll_rx(struct sk_buff *skb)
{
	struct netpoll_info *npinfo;
	unsigned long flags;
	int ret = 0;

	local_irq_save(flags);
	npinfo = rcu_dereference(skb->dev->npinfo);
	if (!npinfo || (!npinfo->rx_np && !npinfo->rx_flags))
		goto out;

	spin_lock(&npinfo->rx_lock);
	/* check rx_flags again with the lock held */
	if (npinfo->rx_flags && __netpoll_rx(skb))
		ret = 1;
	spin_unlock(&npinfo->rx_lock);

out:
	local_irq_restore(flags);
	return ret;
}

static inline int netpoll_rx_on(struct sk_buff *skb)
{
	struct netpoll_info *npinfo = rcu_dereference(skb->dev->npinfo);

	return npinfo && (npinfo->rx_np || npinfo->rx_flags);
}

static inline void *netpoll_poll_lock(struct net_device *dev)
{
	struct netpoll_info *npinfo;
	rcu_read_lock_bh(); /* deal with race on ->npinfo */
	npinfo = rcu_dereference(dev->npinfo);
	if (npinfo) {
		spin_lock(&npinfo->poll_lock);
		npinfo->poll_owner = smp_processor_id();
		return npinfo;
	}
	return NULL;
}

static inline void netpoll_poll_unlock(void *have)
{
	struct netpoll_info *npi = have;

	if (npi) {
		npi->poll_owner = -1;
		spin_unlock(&npi->poll_lock);
	}
	rcu_read_unlock_bh();
}

#else
#define netpoll_rx(a) 0
#define netpoll_rx_on(a) 0
#define netpoll_poll_lock(a) NULL
#define netpoll_poll_unlock(a)
#endif

#endif