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
16 struct 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 int nbuckets;
29 };
30
31 /**
32 * futex_syscall() - SYS_futex syscall wrapper
33 * @uaddr: address of first futex
34 * @op: futex op code
35 * @val: typically expected value of uaddr, but varies by op
36 * @timeout: typically an absolute struct timespec (except where noted
37 * otherwise). Overloaded by some ops
38 * @uaddr2: address of second futex for some ops
39 * @val3: varies by op
40 * @opflags: flags to be bitwise OR'd with op, such as FUTEX_PRIVATE_FLAG
41 *
42 * futex_syscall() is used by all the following futex op wrappers. It can also be
43 * used for misuse and abuse testing. Generally, the specific op wrappers
44 * should be used instead.
45 *
46 * These argument descriptions are the defaults for all
47 * like-named arguments in the following wrappers except where noted below.
48 */
49 static inline int
futex_syscall(volatile u_int32_t * uaddr,int op,u_int32_t val,struct timespec * timeout,volatile u_int32_t * uaddr2,int val3,int opflags)50 futex_syscall(volatile u_int32_t *uaddr, int op, u_int32_t val, struct timespec *timeout,
51 volatile u_int32_t *uaddr2, int val3, int opflags)
52 {
53 return syscall(SYS_futex, uaddr, op | opflags, val, timeout, uaddr2, val3);
54 }
55
56 static inline int
futex_syscall_nr_requeue(volatile u_int32_t * uaddr,int op,u_int32_t val,int nr_requeue,volatile u_int32_t * uaddr2,int val3,int opflags)57 futex_syscall_nr_requeue(volatile u_int32_t *uaddr, int op, u_int32_t val, int nr_requeue,
58 volatile u_int32_t *uaddr2, int val3, int opflags)
59 {
60 return syscall(SYS_futex, uaddr, op | opflags, val, nr_requeue, uaddr2, val3);
61 }
62
63 /**
64 * futex_wait() - block on uaddr with optional timeout
65 * @timeout: relative timeout
66 */
67 static inline int
futex_wait(u_int32_t * uaddr,u_int32_t val,struct timespec * timeout,int opflags)68 futex_wait(u_int32_t *uaddr, u_int32_t val, struct timespec *timeout, int opflags)
69 {
70 return futex_syscall(uaddr, FUTEX_WAIT, val, timeout, NULL, 0, opflags);
71 }
72
73 /**
74 * futex_wake() - wake one or more tasks blocked on uaddr
75 * @nr_wake: wake up to this many tasks
76 */
77 static inline int
futex_wake(u_int32_t * uaddr,int nr_wake,int opflags)78 futex_wake(u_int32_t *uaddr, int nr_wake, int opflags)
79 {
80 return futex_syscall(uaddr, FUTEX_WAKE, nr_wake, NULL, NULL, 0, opflags);
81 }
82
83 /**
84 * futex_lock_pi() - block on uaddr as a PI mutex
85 */
86 static inline int
futex_lock_pi(u_int32_t * uaddr,struct timespec * timeout,int opflags)87 futex_lock_pi(u_int32_t *uaddr, struct timespec *timeout, int opflags)
88 {
89 return futex_syscall(uaddr, FUTEX_LOCK_PI, 0, timeout, NULL, 0, opflags);
90 }
91
92 /**
93 * futex_unlock_pi() - release uaddr as a PI mutex, waking the top waiter
94 */
95 static inline int
futex_unlock_pi(u_int32_t * uaddr,int opflags)96 futex_unlock_pi(u_int32_t *uaddr, int opflags)
97 {
98 return futex_syscall(uaddr, FUTEX_UNLOCK_PI, 0, NULL, NULL, 0, opflags);
99 }
100
101 /**
102 * futex_cmp_requeue() - requeue tasks from uaddr to uaddr2
103 * @nr_wake: wake up to this many tasks
104 * @nr_requeue: requeue up to this many tasks
105 */
106 static inline int
futex_cmp_requeue(u_int32_t * uaddr,u_int32_t val,u_int32_t * uaddr2,int nr_wake,int nr_requeue,int opflags)107 futex_cmp_requeue(u_int32_t *uaddr, u_int32_t val, u_int32_t *uaddr2, int nr_wake,
108 int nr_requeue, int opflags)
109 {
110 return futex_syscall_nr_requeue(uaddr, FUTEX_CMP_REQUEUE, nr_wake, nr_requeue, uaddr2,
111 val, opflags);
112 }
113
114 /**
115 * futex_wait_requeue_pi() - block on uaddr and prepare to requeue to uaddr2
116 * @uaddr: non-PI futex source
117 * @uaddr2: PI futex target
118 *
119 * This is the first half of the requeue_pi mechanism. It shall always be
120 * paired with futex_cmp_requeue_pi().
121 */
122 static inline int
futex_wait_requeue_pi(u_int32_t * uaddr,u_int32_t val,u_int32_t * uaddr2,struct timespec * timeout,int opflags)123 futex_wait_requeue_pi(u_int32_t *uaddr, u_int32_t val, u_int32_t *uaddr2,
124 struct timespec *timeout, int opflags)
125 {
126 return futex_syscall(uaddr, FUTEX_WAIT_REQUEUE_PI, val, timeout, uaddr2, 0,
127 opflags);
128 }
129
130 /**
131 * futex_cmp_requeue_pi() - requeue tasks from uaddr to uaddr2
132 * @uaddr: non-PI futex source
133 * @uaddr2: PI futex target
134 * @nr_requeue: requeue up to this many tasks
135 *
136 * This is the second half of the requeue_pi mechanism. It shall always be
137 * paired with futex_wait_requeue_pi(). The first waker is always awoken.
138 */
139 static inline int
futex_cmp_requeue_pi(u_int32_t * uaddr,u_int32_t val,u_int32_t * uaddr2,int nr_requeue,int opflags)140 futex_cmp_requeue_pi(u_int32_t *uaddr, u_int32_t val, u_int32_t *uaddr2,
141 int nr_requeue, int opflags)
142 {
143 return futex_syscall_nr_requeue(uaddr, FUTEX_CMP_REQUEUE_PI, 1, nr_requeue, uaddr2,
144 val, opflags);
145 }
146
147 void futex_set_nbuckets_param(struct bench_futex_parameters *params);
148 void futex_print_nbuckets(struct bench_futex_parameters *params);
149
150 #endif /* _FUTEX_H */
151