/* SPDX-License-Identifier: GPL-2.0-only *//* * net busy poll support * Copyright(c) 2013 Intel Corporation. * * Author: Eliezer Tamir * * Contact Information: * e1000-devel Mailing List <e1000-devel@lists.sourceforge.net> */ #ifndef _LINUX_NET_BUSY_POLL_H#define _LINUX_NET_BUSY_POLL_H #include <linux/netdevice.h>#include <linux/sched/clock.h>#include <linux/sched/signal.h>#include <net/ip.h>#include <net/xdp.h> /*		0 - Reserved to indicate value not set *     1..NR_CPUS - Reserved for sender_cpu *  NR_CPUS+1..~0 - Region available for NAPI IDs */#define MIN_NAPI_ID ((unsigned int)(NR_CPUS + 1)) static inline bool napi_id_valid(unsigned int napi_id){	return napi_id >= MIN_NAPI_ID;} #define BUSY_POLL_BUDGET 8 #ifdef CONFIG_NET_RX_BUSY_POLL struct napi_struct;extern unsigned int sysctl_net_busy_read __read_mostly;extern unsigned int sysctl_net_busy_poll __read_mostly; static inline bool net_busy_loop_on(void){	return READ_ONCE(sysctl_net_busy_poll);} static inline bool sk_can_busy_loop(const struct sock *sk){	return READ_ONCE(sk->sk_ll_usec) && !signal_pending(current);} bool sk_busy_loop_end(void *p, unsigned long start_time); void napi_busy_loop(unsigned int napi_id,		    bool (*loop_end)(void *, unsigned long),		    void *loop_end_arg, bool prefer_busy_poll, u16 budget); void napi_busy_loop_rcu(unsigned int napi_id,			bool (*loop_end)(void *, unsigned long),			void *loop_end_arg, bool prefer_busy_poll, u16 budget); void napi_suspend_irqs(unsigned int napi_id);void napi_resume_irqs(unsigned int napi_id); #else /* CONFIG_NET_RX_BUSY_POLL */static inline unsigned long net_busy_loop_on(void){	return 0;} static inline bool sk_can_busy_loop(struct sock *sk){	return false;} #endif /* CONFIG_NET_RX_BUSY_POLL */ static inline unsigned long busy_loop_current_time(void){#ifdef CONFIG_NET_RX_BUSY_POLL	return (unsigned long)(ktime_get_ns() >> 10);#else	return 0;#endif} /* in poll/select we use the global sysctl_net_ll_poll value */static inline bool busy_loop_timeout(unsigned long start_time){#ifdef CONFIG_NET_RX_BUSY_POLL	unsigned long bp_usec = READ_ONCE(sysctl_net_busy_poll); 	if (bp_usec) {		unsigned long end_time = start_time + bp_usec;		unsigned long now = busy_loop_current_time(); 		return time_after(now, end_time);	}#endif	return true;} static inline bool sk_busy_loop_timeout(struct sock *sk,					unsigned long start_time){#ifdef CONFIG_NET_RX_BUSY_POLL	unsigned long bp_usec = READ_ONCE(sk->sk_ll_usec); 	if (bp_usec) {		unsigned long end_time = start_time + bp_usec;		unsigned long now = busy_loop_current_time(); 		return time_after(now, end_time);	}#endif	return true;} static inline void sk_busy_loop(struct sock *sk, int nonblock){#ifdef CONFIG_NET_RX_BUSY_POLL	unsigned int napi_id = READ_ONCE(sk->sk_napi_id); 	if (napi_id_valid(napi_id))		napi_busy_loop(napi_id, nonblock ? NULL : sk_busy_loop_end, sk,			       READ_ONCE(sk->sk_prefer_busy_poll),			       READ_ONCE(sk->sk_busy_poll_budget) ?: BUSY_POLL_BUDGET);#endif} /* used in the NIC receive handler to mark the skb */static inline void __skb_mark_napi_id(struct sk_buff *skb,				      const struct gro_node *gro){#ifdef CONFIG_NET_RX_BUSY_POLL	/* If the skb was already marked with a valid NAPI ID, avoid overwriting	 * it.	 */	if (!napi_id_valid(skb->napi_id))		skb->napi_id = gro->cached_napi_id;#endif} static inline void skb_mark_napi_id(struct sk_buff *skb,				    const struct napi_struct *napi){	__skb_mark_napi_id(skb, &napi->gro);} /* used in the protocol handler to propagate the napi_id to the socket */static inline void sk_mark_napi_id(struct sock *sk, const struct sk_buff *skb){#ifdef CONFIG_NET_RX_BUSY_POLL	if (unlikely(READ_ONCE(sk->sk_napi_id) != skb->napi_id))		WRITE_ONCE(sk->sk_napi_id, skb->napi_id);#endif	sk_rx_queue_update(sk, skb);} /* Variant of sk_mark_napi_id() for passive flow setup, * as sk->sk_napi_id and sk->sk_rx_queue_mapping content * needs to be set. */static inline void sk_mark_napi_id_set(struct sock *sk,				       const struct sk_buff *skb){#ifdef CONFIG_NET_RX_BUSY_POLL	WRITE_ONCE(sk->sk_napi_id, skb->napi_id);#endif	sk_rx_queue_set(sk, skb);} static inline void __sk_mark_napi_id_once(struct sock *sk, unsigned int napi_id){#ifdef CONFIG_NET_RX_BUSY_POLL	if (!READ_ONCE(sk->sk_napi_id))		WRITE_ONCE(sk->sk_napi_id, napi_id);#endif} /* variant used for unconnected sockets */static inline void sk_mark_napi_id_once(struct sock *sk,					const struct sk_buff *skb){#ifdef CONFIG_NET_RX_BUSY_POLL	__sk_mark_napi_id_once(sk, skb->napi_id);#endif} #endif /* _LINUX_NET_BUSY_POLL_H */