1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Glibc independent futex library for testing kernel functionality.
4 * Shamelessly stolen from Darren Hart <dvhltc@us.ibm.com>
5 * http://git.kernel.org/cgit/linux/kernel/git/dvhart/futextest.git/
6 */
7
8#ifndef _FUTEX_H
9#define _FUTEX_H
10
11#include <unistd.h>
12#include <sys/syscall.h>
13#include <sys/types.h>
14#include <linux/futex.h>
15
16struct bench_futex_parameters {
17 bool silent;
18 bool fshared;
19 bool mlockall;
20 bool multi; /* lock-pi */
21 bool pi; /* requeue-pi */
22 bool broadcast; /* requeue */
23 unsigned int runtime; /* seconds*/
24 unsigned int nthreads;
25 unsigned int nfutexes;
26 unsigned int nwakes;
27 unsigned int nrequeue;
28};
29
30/**
31 * futex_syscall() - SYS_futex syscall wrapper
32 * @uaddr: address of first futex
33 * @op: futex op code
34 * @val: typically expected value of uaddr, but varies by op
35 * @timeout: typically an absolute struct timespec (except where noted
36 * otherwise). Overloaded by some ops
37 * @uaddr2: address of second futex for some ops
38 * @val3: varies by op
39 * @opflags: flags to be bitwise OR'd with op, such as FUTEX_PRIVATE_FLAG
40 *
41 * futex_syscall() is used by all the following futex op wrappers. It can also be
42 * used for misuse and abuse testing. Generally, the specific op wrappers
43 * should be used instead.
44 *
45 * These argument descriptions are the defaults for all
46 * like-named arguments in the following wrappers except where noted below.
47 */
48static inline int
49futex_syscall(volatile u_int32_t *uaddr, int op, u_int32_t val, struct timespec *timeout,
50 volatile u_int32_t *uaddr2, int val3, int opflags)
51{
52 return syscall(SYS_futex, uaddr, op | opflags, val, timeout, uaddr2, val3);
53}
54
55static inline int
56futex_syscall_nr_requeue(volatile u_int32_t *uaddr, int op, u_int32_t val, int nr_requeue,
57 volatile u_int32_t *uaddr2, int val3, int opflags)
58{
59 return syscall(SYS_futex, uaddr, op | opflags, val, nr_requeue, uaddr2, val3);
60}
61
62/**
63 * futex_wait() - block on uaddr with optional timeout
64 * @timeout: relative timeout
65 */
66static inline int
67futex_wait(u_int32_t *uaddr, u_int32_t val, struct timespec *timeout, int opflags)
68{
69 return futex_syscall(uaddr, FUTEX_WAIT, val, timeout, NULL, val3: 0, opflags);
70}
71
72/**
73 * futex_wake() - wake one or more tasks blocked on uaddr
74 * @nr_wake: wake up to this many tasks
75 */
76static inline int
77futex_wake(u_int32_t *uaddr, int nr_wake, int opflags)
78{
79 return futex_syscall(uaddr, FUTEX_WAKE, val: nr_wake, NULL, NULL, val3: 0, opflags);
80}
81
82/**
83 * futex_lock_pi() - block on uaddr as a PI mutex
84 */
85static inline int
86futex_lock_pi(u_int32_t *uaddr, struct timespec *timeout, int opflags)
87{
88 return futex_syscall(uaddr, FUTEX_LOCK_PI, val: 0, timeout, NULL, val3: 0, opflags);
89}
90
91/**
92 * futex_unlock_pi() - release uaddr as a PI mutex, waking the top waiter
93 */
94static inline int
95futex_unlock_pi(u_int32_t *uaddr, int opflags)
96{
97 return futex_syscall(uaddr, FUTEX_UNLOCK_PI, val: 0, NULL, NULL, val3: 0, opflags);
98}
99
100/**
101* futex_cmp_requeue() - requeue tasks from uaddr to uaddr2
102* @nr_wake: wake up to this many tasks
103* @nr_requeue: requeue up to this many tasks
104*/
105static inline int
106futex_cmp_requeue(u_int32_t *uaddr, u_int32_t val, u_int32_t *uaddr2, int nr_wake,
107 int nr_requeue, int opflags)
108{
109 return futex_syscall_nr_requeue(uaddr, FUTEX_CMP_REQUEUE, val: nr_wake, nr_requeue, uaddr2,
110 val3: val, opflags);
111}
112
113/**
114 * futex_wait_requeue_pi() - block on uaddr and prepare to requeue to uaddr2
115 * @uaddr: non-PI futex source
116 * @uaddr2: PI futex target
117 *
118 * This is the first half of the requeue_pi mechanism. It shall always be
119 * paired with futex_cmp_requeue_pi().
120 */
121static inline int
122futex_wait_requeue_pi(u_int32_t *uaddr, u_int32_t val, u_int32_t *uaddr2,
123 struct timespec *timeout, int opflags)
124{
125 return futex_syscall(uaddr, FUTEX_WAIT_REQUEUE_PI, val, timeout, uaddr2, val3: 0,
126 opflags);
127}
128
129/**
130 * futex_cmp_requeue_pi() - requeue tasks from uaddr to uaddr2
131 * @uaddr: non-PI futex source
132 * @uaddr2: PI futex target
133 * @nr_requeue: requeue up to this many tasks
134 *
135 * This is the second half of the requeue_pi mechanism. It shall always be
136 * paired with futex_wait_requeue_pi(). The first waker is always awoken.
137 */
138static inline int
139futex_cmp_requeue_pi(u_int32_t *uaddr, u_int32_t val, u_int32_t *uaddr2,
140 int nr_requeue, int opflags)
141{
142 return futex_syscall_nr_requeue(uaddr, FUTEX_CMP_REQUEUE_PI, val: 1, nr_requeue, uaddr2,
143 val3: val, opflags);
144}
145
146#endif /* _FUTEX_H */
147

source code of linux/tools/perf/bench/futex.h