bea3348eef
Several devices have multiple independant RX queues per net device, and some have a single interrupt doorbell for several queues. In either case, it's easier to support layouts like that if the structure representing the poll is independant from the net device itself. The signature of the ->poll() call back goes from: int foo_poll(struct net_device *dev, int *budget) to int foo_poll(struct napi_struct *napi, int budget) The caller is returned the number of RX packets processed (or the number of "NAPI credits" consumed if you want to get abstract). The callee no longer messes around bumping dev->quota, *budget, etc. because that is all handled in the caller upon return. The napi_struct is to be embedded in the device driver private data structures. Furthermore, it is the driver's responsibility to disable all NAPI instances in it's ->stop() device close handler. Since the napi_struct is privatized into the driver's private data structures, only the driver knows how to get at all of the napi_struct instances it may have per-device. With lots of help and suggestions from Rusty Russell, Roland Dreier, Michael Chan, Jeff Garzik, and Jamal Hadi Salim. Bug fixes from Thomas Graf, Roland Dreier, Peter Zijlstra, Joseph Fannin, Scott Wood, Hans J. Koch, and Michael Chan. [ Ported to current tree and all drivers converted. Integrated Stephen's follow-on kerneldoc additions, and restored poll_list handling to the old style to fix mutual exclusion issues. -DaveM ] Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
123 lines
2.6 KiB
C
123 lines
2.6 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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#ifndef _LINUX_NETPOLL_H
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#define _LINUX_NETPOLL_H
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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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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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u32 local_ip, remote_ip;
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u16 local_port, remote_port;
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u8 local_mac[ETH_ALEN], remote_mac[ETH_ALEN];
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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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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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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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#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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if (!npinfo || (!npinfo->rx_np && !npinfo->rx_flags))
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return 0;
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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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return ret;
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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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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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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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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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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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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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#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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#endif
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