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 | }; |
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 | */ |
48 | static inline int |
49 | futex_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 | |
55 | static inline int |
56 | futex_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 | */ |
66 | static inline int |
67 | futex_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 | */ |
76 | static inline int |
77 | futex_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 | */ |
85 | static inline int |
86 | futex_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 | */ |
94 | static inline int |
95 | futex_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 | */ |
105 | static inline int |
106 | futex_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 | */ |
121 | static inline int |
122 | futex_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 | */ |
138 | static inline int |
139 | futex_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 | |