1/* SPDX-License-Identifier: GPL-2.0-only */
  2/*
  3 * net busy poll support
  4 * Copyright(c) 2013 Intel Corporation.
  5 *
  6 * Author: Eliezer Tamir
  7 *
  8 * Contact Information:
  9 * e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
 10 */
 11
 12#ifndef _LINUX_NET_BUSY_POLL_H
 13#define _LINUX_NET_BUSY_POLL_H
 14
 15#include <linux/netdevice.h>
 16#include <linux/sched/clock.h>
 17#include <linux/sched/signal.h>
 18#include <net/ip.h>
 19
 20/*		0 - Reserved to indicate value not set
 21 *     1..NR_CPUS - Reserved for sender_cpu
 22 *  NR_CPUS+1..~0 - Region available for NAPI IDs
 23 */
 24#define MIN_NAPI_ID ((unsigned int)(NR_CPUS + 1))
 25
 
 
 26#ifdef CONFIG_NET_RX_BUSY_POLL
 27
 28struct napi_struct;
 29extern unsigned int sysctl_net_busy_read __read_mostly;
 30extern unsigned int sysctl_net_busy_poll __read_mostly;
 31
 32static inline bool net_busy_loop_on(void)
 33{
 34	return sysctl_net_busy_poll;
 35}
 36
 37static inline bool sk_can_busy_loop(const struct sock *sk)
 38{
 39	return sk->sk_ll_usec && !signal_pending(current);
 40}
 41
 42bool sk_busy_loop_end(void *p, unsigned long start_time);
 43
 44void napi_busy_loop(unsigned int napi_id,
 45		    bool (*loop_end)(void *, unsigned long),
 46		    void *loop_end_arg);
 47
 48#else /* CONFIG_NET_RX_BUSY_POLL */
 49static inline unsigned long net_busy_loop_on(void)
 50{
 51	return 0;
 52}
 53
 54static inline bool sk_can_busy_loop(struct sock *sk)
 55{
 56	return false;
 57}
 58
 59#endif /* CONFIG_NET_RX_BUSY_POLL */
 60
 61static inline unsigned long busy_loop_current_time(void)
 62{
 63#ifdef CONFIG_NET_RX_BUSY_POLL
 64	return (unsigned long)(local_clock() >> 10);
 65#else
 66	return 0;
 67#endif
 68}
 69
 70/* in poll/select we use the global sysctl_net_ll_poll value */
 71static inline bool busy_loop_timeout(unsigned long start_time)
 72{
 73#ifdef CONFIG_NET_RX_BUSY_POLL
 74	unsigned long bp_usec = READ_ONCE(sysctl_net_busy_poll);
 75
 76	if (bp_usec) {
 77		unsigned long end_time = start_time + bp_usec;
 78		unsigned long now = busy_loop_current_time();
 79
 80		return time_after(now, end_time);
 81	}
 82#endif
 83	return true;
 84}
 85
 86static inline bool sk_busy_loop_timeout(struct sock *sk,
 87					unsigned long start_time)
 88{
 89#ifdef CONFIG_NET_RX_BUSY_POLL
 90	unsigned long bp_usec = READ_ONCE(sk->sk_ll_usec);
 91
 92	if (bp_usec) {
 93		unsigned long end_time = start_time + bp_usec;
 94		unsigned long now = busy_loop_current_time();
 95
 96		return time_after(now, end_time);
 97	}
 98#endif
 99	return true;
100}
101
102static inline void sk_busy_loop(struct sock *sk, int nonblock)
103{
104#ifdef CONFIG_NET_RX_BUSY_POLL
105	unsigned int napi_id = READ_ONCE(sk->sk_napi_id);
106
107	if (napi_id >= MIN_NAPI_ID)
108		napi_busy_loop(napi_id, nonblock ? NULL : sk_busy_loop_end, sk);
 
 
109#endif
110}
111
112/* used in the NIC receive handler to mark the skb */
113static inline void skb_mark_napi_id(struct sk_buff *skb,
114				    struct napi_struct *napi)
115{
116#ifdef CONFIG_NET_RX_BUSY_POLL
117	/* If the skb was already marked with a valid NAPI ID, avoid overwriting
118	 * it.
119	 */
120	if (skb->napi_id < MIN_NAPI_ID)
121		skb->napi_id = napi->napi_id;
122#endif
123}
124
125/* used in the protocol hanlder to propagate the napi_id to the socket */
126static inline void sk_mark_napi_id(struct sock *sk, const struct sk_buff *skb)
127{
128#ifdef CONFIG_NET_RX_BUSY_POLL
 
 
 
 
 
 
 
 
 
 
 
 
 
 
129	WRITE_ONCE(sk->sk_napi_id, skb->napi_id);
130#endif
131	sk_rx_queue_set(sk, skb);
132}
133
 
 
 
 
 
 
 
 
134/* variant used for unconnected sockets */
135static inline void sk_mark_napi_id_once(struct sock *sk,
136					const struct sk_buff *skb)
137{
138#ifdef CONFIG_NET_RX_BUSY_POLL
139	if (!READ_ONCE(sk->sk_napi_id))
140		WRITE_ONCE(sk->sk_napi_id, skb->napi_id);
 
 
 
 
 
 
 
141#endif
142}
143
144#endif /* _LINUX_NET_BUSY_POLL_H */

  1/* SPDX-License-Identifier: GPL-2.0-only */
  2/*
  3 * net busy poll support
  4 * Copyright(c) 2013 Intel Corporation.
  5 *
  6 * Author: Eliezer Tamir
  7 *
  8 * Contact Information:
  9 * e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
 10 */
 11
 12#ifndef _LINUX_NET_BUSY_POLL_H
 13#define _LINUX_NET_BUSY_POLL_H
 14
 15#include <linux/netdevice.h>
 16#include <linux/sched/clock.h>
 17#include <linux/sched/signal.h>
 18#include <net/ip.h>
 19
 20/*		0 - Reserved to indicate value not set
 21 *     1..NR_CPUS - Reserved for sender_cpu
 22 *  NR_CPUS+1..~0 - Region available for NAPI IDs
 23 */
 24#define MIN_NAPI_ID ((unsigned int)(NR_CPUS + 1))
 25
 26#define BUSY_POLL_BUDGET 8
 27
 28#ifdef CONFIG_NET_RX_BUSY_POLL
 29
 30struct napi_struct;
 31extern unsigned int sysctl_net_busy_read __read_mostly;
 32extern unsigned int sysctl_net_busy_poll __read_mostly;
 33
 34static inline bool net_busy_loop_on(void)
 35{
 36	return READ_ONCE(sysctl_net_busy_poll);
 37}
 38
 39static inline bool sk_can_busy_loop(const struct sock *sk)
 40{
 41	return READ_ONCE(sk->sk_ll_usec) && !signal_pending(current);
 42}
 43
 44bool sk_busy_loop_end(void *p, unsigned long start_time);
 45
 46void napi_busy_loop(unsigned int napi_id,
 47		    bool (*loop_end)(void *, unsigned long),
 48		    void *loop_end_arg, bool prefer_busy_poll, u16 budget);
 49
 50#else /* CONFIG_NET_RX_BUSY_POLL */
 51static inline unsigned long net_busy_loop_on(void)
 52{
 53	return 0;
 54}
 55
 56static inline bool sk_can_busy_loop(struct sock *sk)
 57{
 58	return false;
 59}
 60
 61#endif /* CONFIG_NET_RX_BUSY_POLL */
 62
 63static inline unsigned long busy_loop_current_time(void)
 64{
 65#ifdef CONFIG_NET_RX_BUSY_POLL
 66	return (unsigned long)(local_clock() >> 10);
 67#else
 68	return 0;
 69#endif
 70}
 71
 72/* in poll/select we use the global sysctl_net_ll_poll value */
 73static inline bool busy_loop_timeout(unsigned long start_time)
 74{
 75#ifdef CONFIG_NET_RX_BUSY_POLL
 76	unsigned long bp_usec = READ_ONCE(sysctl_net_busy_poll);
 77
 78	if (bp_usec) {
 79		unsigned long end_time = start_time + bp_usec;
 80		unsigned long now = busy_loop_current_time();
 81
 82		return time_after(now, end_time);
 83	}
 84#endif
 85	return true;
 86}
 87
 88static inline bool sk_busy_loop_timeout(struct sock *sk,
 89					unsigned long start_time)
 90{
 91#ifdef CONFIG_NET_RX_BUSY_POLL
 92	unsigned long bp_usec = READ_ONCE(sk->sk_ll_usec);
 93
 94	if (bp_usec) {
 95		unsigned long end_time = start_time + bp_usec;
 96		unsigned long now = busy_loop_current_time();
 97
 98		return time_after(now, end_time);
 99	}
100#endif
101	return true;
102}
103
104static inline void sk_busy_loop(struct sock *sk, int nonblock)
105{
106#ifdef CONFIG_NET_RX_BUSY_POLL
107	unsigned int napi_id = READ_ONCE(sk->sk_napi_id);
108
109	if (napi_id >= MIN_NAPI_ID)
110		napi_busy_loop(napi_id, nonblock ? NULL : sk_busy_loop_end, sk,
111			       READ_ONCE(sk->sk_prefer_busy_poll),
112			       READ_ONCE(sk->sk_busy_poll_budget) ?: BUSY_POLL_BUDGET);
113#endif
114}
115
116/* used in the NIC receive handler to mark the skb */
117static inline void skb_mark_napi_id(struct sk_buff *skb,
118				    struct napi_struct *napi)
119{
120#ifdef CONFIG_NET_RX_BUSY_POLL
121	/* If the skb was already marked with a valid NAPI ID, avoid overwriting
122	 * it.
123	 */
124	if (skb->napi_id < MIN_NAPI_ID)
125		skb->napi_id = napi->napi_id;
126#endif
127}
128
129/* used in the protocol hanlder to propagate the napi_id to the socket */
130static inline void sk_mark_napi_id(struct sock *sk, const struct sk_buff *skb)
131{
132#ifdef CONFIG_NET_RX_BUSY_POLL
133	if (unlikely(READ_ONCE(sk->sk_napi_id) != skb->napi_id))
134		WRITE_ONCE(sk->sk_napi_id, skb->napi_id);
135#endif
136	sk_rx_queue_update(sk, skb);
137}
138
139/* Variant of sk_mark_napi_id() for passive flow setup,
140 * as sk->sk_napi_id and sk->sk_rx_queue_mapping content
141 * needs to be set.
142 */
143static inline void sk_mark_napi_id_set(struct sock *sk,
144				       const struct sk_buff *skb)
145{
146#ifdef CONFIG_NET_RX_BUSY_POLL
147	WRITE_ONCE(sk->sk_napi_id, skb->napi_id);
148#endif
149	sk_rx_queue_set(sk, skb);
150}
151
152static inline void __sk_mark_napi_id_once(struct sock *sk, unsigned int napi_id)
153{
154#ifdef CONFIG_NET_RX_BUSY_POLL
155	if (!READ_ONCE(sk->sk_napi_id))
156		WRITE_ONCE(sk->sk_napi_id, napi_id);
157#endif
158}
159
160/* variant used for unconnected sockets */
161static inline void sk_mark_napi_id_once(struct sock *sk,
162					const struct sk_buff *skb)
163{
164#ifdef CONFIG_NET_RX_BUSY_POLL
165	__sk_mark_napi_id_once(sk, skb->napi_id);
166#endif
167}
168
169static inline void sk_mark_napi_id_once_xdp(struct sock *sk,
170					    const struct xdp_buff *xdp)
171{
172#ifdef CONFIG_NET_RX_BUSY_POLL
173	__sk_mark_napi_id_once(sk, xdp->rxq->napi_id);
174#endif
175}
176
177#endif /* _LINUX_NET_BUSY_POLL_H */