tools/perf/bench/futex.h

   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, 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, nr_wake, NULL, NULL, 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, 0, timeout, NULL, 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, 0, NULL, NULL, 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, nr_wake, nr_requeue, uaddr2,
 110                                         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, 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, 1, nr_requeue, uaddr2,
 143                                         val, opflags);
 144 }
 145
 146 #endif /* _FUTEX_H */