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	 d9452e9f81
			
		
	
	
		d9452e9f81
		
	
	
	
	
		
			
			Based upon a report by Andrew Morton and code analysis done by Jarek Poplawski. This reverts33f807ba0d("[NETPOLL]: Kill NETPOLL_RX_DROP, set but never tested.") andc7b6ea24b4("[NETPOLL]: Don't need rx_flags."). The rx_flags did get tested for zero vs. non-zero and therefore we do need those tests and that code which sets NETPOLL_RX_DROP et al. Signed-off-by: David S. Miller <davem@davemloft.net>
		
			
				
	
	
		
			124 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			124 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Common code for low-level network console, dump, and debugger code
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|  *
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|  * Derived from netconsole, kgdb-over-ethernet, and netdump patches
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|  */
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| 
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| #ifndef _LINUX_NETPOLL_H
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| #define _LINUX_NETPOLL_H
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| 
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| #include <linux/netdevice.h>
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| #include <linux/interrupt.h>
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| #include <linux/rcupdate.h>
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| #include <linux/list.h>
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| 
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| struct netpoll {
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| 	struct net_device *dev;
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| 	char dev_name[IFNAMSIZ];
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| 	const char *name;
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| 	void (*rx_hook)(struct netpoll *, int, char *, int);
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| 
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| 	u32 local_ip, remote_ip;
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| 	u16 local_port, remote_port;
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| 	u8 remote_mac[ETH_ALEN];
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| };
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| 
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| struct netpoll_info {
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| 	atomic_t refcnt;
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| 	int rx_flags;
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| 	spinlock_t rx_lock;
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| 	struct netpoll *rx_np; /* netpoll that registered an rx_hook */
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| 	struct sk_buff_head arp_tx; /* list of arp requests to reply to */
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| 	struct sk_buff_head txq;
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| 	struct delayed_work tx_work;
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| };
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| 
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| void netpoll_poll(struct netpoll *np);
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| void netpoll_send_udp(struct netpoll *np, const char *msg, int len);
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| void netpoll_print_options(struct netpoll *np);
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| int netpoll_parse_options(struct netpoll *np, char *opt);
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| int netpoll_setup(struct netpoll *np);
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| int netpoll_trap(void);
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| void netpoll_set_trap(int trap);
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| void netpoll_cleanup(struct netpoll *np);
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| int __netpoll_rx(struct sk_buff *skb);
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| 
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| 
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| #ifdef CONFIG_NETPOLL
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| static inline int netpoll_rx(struct sk_buff *skb)
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| {
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| 	struct netpoll_info *npinfo = skb->dev->npinfo;
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| 	unsigned long flags;
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| 	int ret = 0;
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| 
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| 	if (!npinfo || (!npinfo->rx_np && !npinfo->rx_flags))
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| 		return 0;
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| 
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| 	spin_lock_irqsave(&npinfo->rx_lock, flags);
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| 	/* check rx_flags again with the lock held */
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| 	if (npinfo->rx_flags && __netpoll_rx(skb))
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| 		ret = 1;
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| 	spin_unlock_irqrestore(&npinfo->rx_lock, flags);
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| 
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| 	return ret;
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| }
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| 
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| static inline int netpoll_receive_skb(struct sk_buff *skb)
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| {
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| 	if (!list_empty(&skb->dev->napi_list))
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| 		return netpoll_rx(skb);
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| 	return 0;
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| }
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| 
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| static inline void *netpoll_poll_lock(struct napi_struct *napi)
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| {
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| 	struct net_device *dev = napi->dev;
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| 
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| 	rcu_read_lock(); /* deal with race on ->npinfo */
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| 	if (dev && dev->npinfo) {
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| 		spin_lock(&napi->poll_lock);
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| 		napi->poll_owner = smp_processor_id();
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| 		return napi;
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| 	}
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| 	return NULL;
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| }
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| 
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| static inline void netpoll_poll_unlock(void *have)
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| {
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| 	struct napi_struct *napi = have;
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| 
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| 	if (napi) {
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| 		napi->poll_owner = -1;
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| 		spin_unlock(&napi->poll_lock);
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| 	}
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| 	rcu_read_unlock();
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| }
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| 
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| static inline void netpoll_netdev_init(struct net_device *dev)
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| {
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| 	INIT_LIST_HEAD(&dev->napi_list);
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| }
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| 
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| #else
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| static inline int netpoll_rx(struct sk_buff *skb)
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| {
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| 	return 0;
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| }
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| static inline int netpoll_receive_skb(struct sk_buff *skb)
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| {
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| 	return 0;
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| }
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| static inline void *netpoll_poll_lock(struct napi_struct *napi)
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| {
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| 	return NULL;
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| }
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| static inline void netpoll_poll_unlock(void *have)
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| {
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| }
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| static inline void netpoll_netdev_init(struct net_device *dev)
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| {
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| }
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| #endif
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| 
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| #endif
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