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1/*
2 * net busy poll support
3 * Copyright(c) 2013 Intel Corporation.
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms and conditions of the GNU General Public License,
7 * version 2, as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 *
14 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
17 *
18 * Author: Eliezer Tamir
19 *
20 * Contact Information:
21 * e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
22 */
23
24#ifndef _LINUX_NET_BUSY_POLL_H
25#define _LINUX_NET_BUSY_POLL_H
26
27#include <linux/netdevice.h>
28#include <linux/sched/clock.h>
29#include <linux/sched/signal.h>
30#include <net/ip.h>
31
32/* 0 - Reserved to indicate value not set
33 * 1..NR_CPUS - Reserved for sender_cpu
34 * NR_CPUS+1..~0 - Region available for NAPI IDs
35 */
36#define MIN_NAPI_ID ((unsigned int)(NR_CPUS + 1))
37
38#ifdef CONFIG_NET_RX_BUSY_POLL
39
40struct napi_struct;
41extern unsigned int sysctl_net_busy_read __read_mostly;
42extern unsigned int sysctl_net_busy_poll __read_mostly;
43
44static inline bool net_busy_loop_on(void)
45{
46 return sysctl_net_busy_poll;
47}
48
49static inline bool sk_can_busy_loop(const struct sock *sk)
50{
51 return sk->sk_ll_usec && !signal_pending(current);
52}
53
54bool sk_busy_loop_end(void *p, unsigned long start_time);
55
56void napi_busy_loop(unsigned int napi_id,
57 bool (*loop_end)(void *, unsigned long),
58 void *loop_end_arg);
59
60#else /* CONFIG_NET_RX_BUSY_POLL */
61static inline unsigned long net_busy_loop_on(void)
62{
63 return 0;
64}
65
66static inline bool sk_can_busy_loop(struct sock *sk)
67{
68 return false;
69}
70
71#endif /* CONFIG_NET_RX_BUSY_POLL */
72
73static inline unsigned long busy_loop_current_time(void)
74{
75#ifdef CONFIG_NET_RX_BUSY_POLL
76 return (unsigned long)(local_clock() >> 10);
77#else
78 return 0;
79#endif
80}
81
82/* in poll/select we use the global sysctl_net_ll_poll value */
83static inline bool busy_loop_timeout(unsigned long start_time)
84{
85#ifdef CONFIG_NET_RX_BUSY_POLL
86 unsigned long bp_usec = READ_ONCE(sysctl_net_busy_poll);
87
88 if (bp_usec) {
89 unsigned long end_time = start_time + bp_usec;
90 unsigned long now = busy_loop_current_time();
91
92 return time_after(now, end_time);
93 }
94#endif
95 return true;
96}
97
98static inline bool sk_busy_loop_timeout(struct sock *sk,
99 unsigned long start_time)
100{
101#ifdef CONFIG_NET_RX_BUSY_POLL
102 unsigned long bp_usec = READ_ONCE(sk->sk_ll_usec);
103
104 if (bp_usec) {
105 unsigned long end_time = start_time + bp_usec;
106 unsigned long now = busy_loop_current_time();
107
108 return time_after(now, end_time);
109 }
110#endif
111 return true;
112}
113
114static inline void sk_busy_loop(struct sock *sk, int nonblock)
115{
116#ifdef CONFIG_NET_RX_BUSY_POLL
117 unsigned int napi_id = READ_ONCE(sk->sk_napi_id);
118
119 if (napi_id >= MIN_NAPI_ID)
120 napi_busy_loop(napi_id, nonblock ? NULL : sk_busy_loop_end, sk);
121#endif
122}
123
124/* used in the NIC receive handler to mark the skb */
125static inline void skb_mark_napi_id(struct sk_buff *skb,
126 struct napi_struct *napi)
127{
128#ifdef CONFIG_NET_RX_BUSY_POLL
129 skb->napi_id = napi->napi_id;
130#endif
131}
132
133/* used in the protocol hanlder to propagate the napi_id to the socket */
134static inline void sk_mark_napi_id(struct sock *sk, const struct sk_buff *skb)
135{
136#ifdef CONFIG_NET_RX_BUSY_POLL
137 sk->sk_napi_id = skb->napi_id;
138#endif
139}
140
141/* variant used for unconnected sockets */
142static inline void sk_mark_napi_id_once(struct sock *sk,
143 const struct sk_buff *skb)
144{
145#ifdef CONFIG_NET_RX_BUSY_POLL
146 if (!sk->sk_napi_id)
147 sk->sk_napi_id = skb->napi_id;
148#endif
149}
150
151#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#include <net/xdp.h>
20
21/* 0 - Reserved to indicate value not set
22 * 1..NR_CPUS - Reserved for sender_cpu
23 * NR_CPUS+1..~0 - Region available for NAPI IDs
24 */
25#define MIN_NAPI_ID ((unsigned int)(NR_CPUS + 1))
26
27#define BUSY_POLL_BUDGET 8
28
29#ifdef CONFIG_NET_RX_BUSY_POLL
30
31struct napi_struct;
32extern unsigned int sysctl_net_busy_read __read_mostly;
33extern unsigned int sysctl_net_busy_poll __read_mostly;
34
35static inline bool net_busy_loop_on(void)
36{
37 return READ_ONCE(sysctl_net_busy_poll);
38}
39
40static inline bool sk_can_busy_loop(const struct sock *sk)
41{
42 return READ_ONCE(sk->sk_ll_usec) && !signal_pending(current);
43}
44
45bool sk_busy_loop_end(void *p, unsigned long start_time);
46
47void napi_busy_loop(unsigned int napi_id,
48 bool (*loop_end)(void *, unsigned long),
49 void *loop_end_arg, bool prefer_busy_poll, u16 budget);
50
51#else /* CONFIG_NET_RX_BUSY_POLL */
52static inline unsigned long net_busy_loop_on(void)
53{
54 return 0;
55}
56
57static inline bool sk_can_busy_loop(struct sock *sk)
58{
59 return false;
60}
61
62#endif /* CONFIG_NET_RX_BUSY_POLL */
63
64static inline unsigned long busy_loop_current_time(void)
65{
66#ifdef CONFIG_NET_RX_BUSY_POLL
67 return (unsigned long)(local_clock() >> 10);
68#else
69 return 0;
70#endif
71}
72
73/* in poll/select we use the global sysctl_net_ll_poll value */
74static inline bool busy_loop_timeout(unsigned long start_time)
75{
76#ifdef CONFIG_NET_RX_BUSY_POLL
77 unsigned long bp_usec = READ_ONCE(sysctl_net_busy_poll);
78
79 if (bp_usec) {
80 unsigned long end_time = start_time + bp_usec;
81 unsigned long now = busy_loop_current_time();
82
83 return time_after(now, end_time);
84 }
85#endif
86 return true;
87}
88
89static inline bool sk_busy_loop_timeout(struct sock *sk,
90 unsigned long start_time)
91{
92#ifdef CONFIG_NET_RX_BUSY_POLL
93 unsigned long bp_usec = READ_ONCE(sk->sk_ll_usec);
94
95 if (bp_usec) {
96 unsigned long end_time = start_time + bp_usec;
97 unsigned long now = busy_loop_current_time();
98
99 return time_after(now, end_time);
100 }
101#endif
102 return true;
103}
104
105static inline void sk_busy_loop(struct sock *sk, int nonblock)
106{
107#ifdef CONFIG_NET_RX_BUSY_POLL
108 unsigned int napi_id = READ_ONCE(sk->sk_napi_id);
109
110 if (napi_id >= MIN_NAPI_ID)
111 napi_busy_loop(napi_id, nonblock ? NULL : sk_busy_loop_end, sk,
112 READ_ONCE(sk->sk_prefer_busy_poll),
113 READ_ONCE(sk->sk_busy_poll_budget) ?: BUSY_POLL_BUDGET);
114#endif
115}
116
117/* used in the NIC receive handler to mark the skb */
118static inline void skb_mark_napi_id(struct sk_buff *skb,
119 struct napi_struct *napi)
120{
121#ifdef CONFIG_NET_RX_BUSY_POLL
122 /* If the skb was already marked with a valid NAPI ID, avoid overwriting
123 * it.
124 */
125 if (skb->napi_id < MIN_NAPI_ID)
126 skb->napi_id = napi->napi_id;
127#endif
128}
129
130/* used in the protocol hanlder to propagate the napi_id to the socket */
131static inline void sk_mark_napi_id(struct sock *sk, const struct sk_buff *skb)
132{
133#ifdef CONFIG_NET_RX_BUSY_POLL
134 if (unlikely(READ_ONCE(sk->sk_napi_id) != skb->napi_id))
135 WRITE_ONCE(sk->sk_napi_id, skb->napi_id);
136#endif
137 sk_rx_queue_update(sk, skb);
138}
139
140/* Variant of sk_mark_napi_id() for passive flow setup,
141 * as sk->sk_napi_id and sk->sk_rx_queue_mapping content
142 * needs to be set.
143 */
144static inline void sk_mark_napi_id_set(struct sock *sk,
145 const struct sk_buff *skb)
146{
147#ifdef CONFIG_NET_RX_BUSY_POLL
148 WRITE_ONCE(sk->sk_napi_id, skb->napi_id);
149#endif
150 sk_rx_queue_set(sk, skb);
151}
152
153static inline void __sk_mark_napi_id_once(struct sock *sk, unsigned int napi_id)
154{
155#ifdef CONFIG_NET_RX_BUSY_POLL
156 if (!READ_ONCE(sk->sk_napi_id))
157 WRITE_ONCE(sk->sk_napi_id, napi_id);
158#endif
159}
160
161/* variant used for unconnected sockets */
162static inline void sk_mark_napi_id_once(struct sock *sk,
163 const struct sk_buff *skb)
164{
165#ifdef CONFIG_NET_RX_BUSY_POLL
166 __sk_mark_napi_id_once(sk, skb->napi_id);
167#endif
168}
169
170static inline void sk_mark_napi_id_once_xdp(struct sock *sk,
171 const struct xdp_buff *xdp)
172{
173#ifdef CONFIG_NET_RX_BUSY_POLL
174 __sk_mark_napi_id_once(sk, xdp->rxq->napi_id);
175#endif
176}
177
178#endif /* _LINUX_NET_BUSY_POLL_H */