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 multi; /* lock-pi */ 20 unsigned int runtime; /* seconds*/ 21 unsigned int nthreads; 22 unsigned int nfutexes; 23 unsigned int nwakes; 24 unsigned int nrequeue; 25 }; 26 27 /** 28 * futex() - SYS_futex syscall wrapper 29 * @uaddr: address of first futex 30 * @op: futex op code 31 * @val: typically expected value of uaddr, but varies by op 32 * @timeout: typically an absolute struct timespec (except where noted 33 * otherwise). Overloaded by some ops 34 * @uaddr2: address of second futex for some ops\ 35 * @val3: varies by op 36 * @opflags: flags to be bitwise OR'd with op, such as FUTEX_PRIVATE_FLAG 37 * 38 * futex() is used by all the following futex op wrappers. It can also be 39 * used for misuse and abuse testing. Generally, the specific op wrappers 40 * should be used instead. It is a macro instead of an static inline function as 41 * some of the types over overloaded (timeout is used for nr_requeue for 42 * example). 43 * 44 * These argument descriptions are the defaults for all 45 * like-named arguments in the following wrappers except where noted below. 46 */ 47 #define futex(uaddr, op, val, timeout, uaddr2, val3, opflags) \ 48 syscall(SYS_futex, uaddr, op | opflags, val, timeout, uaddr2, val3) 49 50 /** 51 * futex_wait() - block on uaddr with optional timeout 52 * @timeout: relative timeout 53 */ 54 static inline int 55 futex_wait(u_int32_t *uaddr, u_int32_t val, struct timespec *timeout, int opflags) 56 { 57 return futex(uaddr, FUTEX_WAIT, val, timeout, NULL, 0, opflags); 58 } 59 60 /** 61 * futex_wake() - wake one or more tasks blocked on uaddr 62 * @nr_wake: wake up to this many tasks 63 */ 64 static inline int 65 futex_wake(u_int32_t *uaddr, int nr_wake, int opflags) 66 { 67 return futex(uaddr, FUTEX_WAKE, nr_wake, NULL, NULL, 0, opflags); 68 } 69 70 /** 71 * futex_lock_pi() - block on uaddr as a PI mutex 72 */ 73 static inline int 74 futex_lock_pi(u_int32_t *uaddr, struct timespec *timeout, int opflags) 75 { 76 return futex(uaddr, FUTEX_LOCK_PI, 0, timeout, NULL, 0, opflags); 77 } 78 79 /** 80 * futex_unlock_pi() - release uaddr as a PI mutex, waking the top waiter 81 */ 82 static inline int 83 futex_unlock_pi(u_int32_t *uaddr, int opflags) 84 { 85 return futex(uaddr, FUTEX_UNLOCK_PI, 0, NULL, NULL, 0, opflags); 86 } 87 88 /** 89 * futex_cmp_requeue() - requeue tasks from uaddr to uaddr2 90 * @nr_wake: wake up to this many tasks 91 * @nr_requeue: requeue up to this many tasks 92 */ 93 static inline int 94 futex_cmp_requeue(u_int32_t *uaddr, u_int32_t val, u_int32_t *uaddr2, int nr_wake, 95 int nr_requeue, int opflags) 96 { 97 return futex(uaddr, FUTEX_CMP_REQUEUE, nr_wake, nr_requeue, uaddr2, 98 val, opflags); 99 } 100 #endif /* _FUTEX_H */ 101