Contributors: 21
Author Tokens Token Proportion Commits Commit Proportion
Eliezer Tamir 166 25.42% 10 20.83%
Eric Dumazet 132 20.21% 9 18.75%
Alexander Duyck 115 17.61% 3 6.25%
Sridhar Samudrala 93 14.24% 1 2.08%
Björn Töpel 39 5.97% 3 6.25%
Andi Kleen 25 3.83% 1 2.08%
Amritha Nambiar 15 2.30% 2 4.17%
Martin Karsten 13 1.99% 1 2.08%
Linus Torvalds (pre-git) 9 1.38% 4 8.33%
Américo Wang 8 1.23% 2 4.17%
Daniel Borkmann 7 1.07% 1 2.08%
Ingo Molnar 6 0.92% 2 4.17%
Patrick Ohly 5 0.77% 1 2.08%
Stephen Hemminger 4 0.61% 1 2.08%
Hannes Eder 3 0.46% 1 2.08%
Stefan Roesch 3 0.46% 1 2.08%
Jesper Dangaard Brouer 3 0.46% 1 2.08%
Kuniyuki Iwashima 3 0.46% 1 2.08%
Thomas Gleixner 2 0.31% 1 2.08%
Simon Horman 1 0.15% 1 2.08%
Jeff Garzik 1 0.15% 1 2.08%
Total 653 48 
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/* 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))

#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 >= MIN_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,
				    struct napi_struct *napi)
{
#ifdef CONFIG_NET_RX_BUSY_POLL
	/* If the skb was already marked with a valid NAPI ID, avoid overwriting
	 * it.
	 */
	if (skb->napi_id < MIN_NAPI_ID)
		skb->napi_id = napi->napi_id;
#endif
}

/* 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 */