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 bool buckets_immutable; 30 }; 31 32 /** 33 * futex_syscall() - SYS_futex syscall wrapper 34 * @uaddr: address of first futex 35 * @op: futex op code 36 * @val: typically expected value of uaddr, but varies by op 37 * @timeout: typically an absolute struct timespec (except where noted 38 * otherwise). Overloaded by some ops 39 * @uaddr2: address of second futex for some ops 40 * @val3: varies by op 41 * @opflags: flags to be bitwise OR'd with op, such as FUTEX_PRIVATE_FLAG 42 * 43 * futex_syscall() is used by all the following futex op wrappers. It can also be 44 * used for misuse and abuse testing. Generally, the specific op wrappers 45 * should be used instead. 46 * 47 * These argument descriptions are the defaults for all 48 * like-named arguments in the following wrappers except where noted below. 49 */ 50 static inline int 51 futex_syscall(volatile u_int32_t *uaddr, int op, u_int32_t val, struct timespec *timeout, 52 volatile u_int32_t *uaddr2, int val3, int opflags) 53 { 54 return syscall(SYS_futex, uaddr, op | opflags, val, timeout, uaddr2, val3); 55 } 56 57 static inline int 58 futex_syscall_nr_requeue(volatile u_int32_t *uaddr, int op, u_int32_t val, int nr_requeue, 59 volatile u_int32_t *uaddr2, int val3, int opflags) 60 { 61 return syscall(SYS_futex, uaddr, op | opflags, val, nr_requeue, uaddr2, val3); 62 } 63 64 /** 65 * futex_wait() - block on uaddr with optional timeout 66 * @timeout: relative timeout 67 */ 68 static inline int 69 futex_wait(u_int32_t *uaddr, u_int32_t val, struct timespec *timeout, int opflags) 70 { 71 return futex_syscall(uaddr, FUTEX_WAIT, val, timeout, NULL, 0, opflags); 72 } 73 74 /** 75 * futex_wake() - wake one or more tasks blocked on uaddr 76 * @nr_wake: wake up to this many tasks 77 */ 78 static inline int 79 futex_wake(u_int32_t *uaddr, int nr_wake, int opflags) 80 { 81 return futex_syscall(uaddr, FUTEX_WAKE, nr_wake, NULL, NULL, 0, opflags); 82 } 83 84 /** 85 * futex_lock_pi() - block on uaddr as a PI mutex 86 */ 87 static inline int 88 futex_lock_pi(u_int32_t *uaddr, struct timespec *timeout, int opflags) 89 { 90 return futex_syscall(uaddr, FUTEX_LOCK_PI, 0, timeout, NULL, 0, opflags); 91 } 92 93 /** 94 * futex_unlock_pi() - release uaddr as a PI mutex, waking the top waiter 95 */ 96 static inline int 97 futex_unlock_pi(u_int32_t *uaddr, int opflags) 98 { 99 return futex_syscall(uaddr, FUTEX_UNLOCK_PI, 0, NULL, NULL, 0, opflags); 100 } 101 102 /** 103 * futex_cmp_requeue() - requeue tasks from uaddr to uaddr2 104 * @nr_wake: wake up to this many tasks 105 * @nr_requeue: requeue up to this many tasks 106 */ 107 static inline int 108 futex_cmp_requeue(u_int32_t *uaddr, u_int32_t val, u_int32_t *uaddr2, int nr_wake, 109 int nr_requeue, int opflags) 110 { 111 return futex_syscall_nr_requeue(uaddr, FUTEX_CMP_REQUEUE, nr_wake, nr_requeue, uaddr2, 112 val, opflags); 113 } 114 115 /** 116 * futex_wait_requeue_pi() - block on uaddr and prepare to requeue to uaddr2 117 * @uaddr: non-PI futex source 118 * @uaddr2: PI futex target 119 * 120 * This is the first half of the requeue_pi mechanism. It shall always be 121 * paired with futex_cmp_requeue_pi(). 122 */ 123 static inline int 124 futex_wait_requeue_pi(u_int32_t *uaddr, u_int32_t val, u_int32_t *uaddr2, 125 struct timespec *timeout, int opflags) 126 { 127 return futex_syscall(uaddr, FUTEX_WAIT_REQUEUE_PI, val, timeout, uaddr2, 0, 128 opflags); 129 } 130 131 /** 132 * futex_cmp_requeue_pi() - requeue tasks from uaddr to uaddr2 133 * @uaddr: non-PI futex source 134 * @uaddr2: PI futex target 135 * @nr_requeue: requeue up to this many tasks 136 * 137 * This is the second half of the requeue_pi mechanism. It shall always be 138 * paired with futex_wait_requeue_pi(). The first waker is always awoken. 139 */ 140 static inline int 141 futex_cmp_requeue_pi(u_int32_t *uaddr, u_int32_t val, u_int32_t *uaddr2, 142 int nr_requeue, int opflags) 143 { 144 return futex_syscall_nr_requeue(uaddr, FUTEX_CMP_REQUEUE_PI, 1, nr_requeue, uaddr2, 145 val, opflags); 146 } 147 148 void futex_set_nbuckets_param(struct bench_futex_parameters *params); 149 void futex_print_nbuckets(struct bench_futex_parameters *params); 150 151 #endif /* _FUTEX_H */ 152