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 */ 147