xref: /openbmc/linux/include/uapi/linux/sem.h (revision 2a785996)
1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 #ifndef _UAPI_LINUX_SEM_H
3 #define _UAPI_LINUX_SEM_H
4 
5 #include <linux/ipc.h>
6 
7 /* semop flags */
8 #define SEM_UNDO        0x1000  /* undo the operation on exit */
9 
10 /* semctl Command Definitions. */
11 #define GETPID  11       /* get sempid */
12 #define GETVAL  12       /* get semval */
13 #define GETALL  13       /* get all semval's */
14 #define GETNCNT 14       /* get semncnt */
15 #define GETZCNT 15       /* get semzcnt */
16 #define SETVAL  16       /* set semval */
17 #define SETALL  17       /* set all semval's */
18 
19 /* ipcs ctl cmds */
20 #define SEM_STAT 18
21 #define SEM_INFO 19
22 #define SEM_STAT_ANY 20
23 
24 /* Obsolete, used only for backwards compatibility and libc5 compiles */
25 struct semid_ds {
26 	struct ipc_perm	sem_perm;		/* permissions .. see ipc.h */
27 	__kernel_old_time_t sem_otime;		/* last semop time */
28 	__kernel_old_time_t sem_ctime;		/* create/last semctl() time */
29 	struct sem	*sem_base;		/* ptr to first semaphore in array */
30 	struct sem_queue *sem_pending;		/* pending operations to be processed */
31 	struct sem_queue **sem_pending_last;	/* last pending operation */
32 	struct sem_undo	*undo;			/* undo requests on this array */
33 	unsigned short	sem_nsems;		/* no. of semaphores in array */
34 };
35 
36 /* Include the definition of semid64_ds */
37 #include <asm/sembuf.h>
38 
39 /* semop system calls takes an array of these. */
40 struct sembuf {
41 	unsigned short  sem_num;	/* semaphore index in array */
42 	short		sem_op;		/* semaphore operation */
43 	short		sem_flg;	/* operation flags */
44 };
45 
46 /* arg for semctl system calls. */
47 union semun {
48 	int val;			/* value for SETVAL */
49 	struct semid_ds __user *buf;	/* buffer for IPC_STAT & IPC_SET */
50 	unsigned short __user *array;	/* array for GETALL & SETALL */
51 	struct seminfo __user *__buf;	/* buffer for IPC_INFO */
52 	void __user *__pad;
53 };
54 
55 struct  seminfo {
56 	int semmap;
57 	int semmni;
58 	int semmns;
59 	int semmnu;
60 	int semmsl;
61 	int semopm;
62 	int semume;
63 	int semusz;
64 	int semvmx;
65 	int semaem;
66 };
67 
68 /*
69  * SEMMNI, SEMMSL and SEMMNS are default values which can be
70  * modified by sysctl.
71  * The values has been chosen to be larger than necessary for any
72  * known configuration.
73  *
74  * SEMOPM should not be increased beyond 1000, otherwise there is the
75  * risk that semop()/semtimedop() fails due to kernel memory fragmentation when
76  * allocating the sop array.
77  */
78 
79 
80 #define SEMMNI  32000           /* <= IPCMNI  max # of semaphore identifiers */
81 #define SEMMSL  32000           /* <= INT_MAX max num of semaphores per id */
82 #define SEMMNS  (SEMMNI*SEMMSL) /* <= INT_MAX max # of semaphores in system */
83 #define SEMOPM  500	        /* <= 1 000 max num of ops per semop call */
84 #define SEMVMX  32767           /* <= 32767 semaphore maximum value */
85 #define SEMAEM  SEMVMX          /* adjust on exit max value */
86 
87 /* unused */
88 #define SEMUME  SEMOPM          /* max num of undo entries per process */
89 #define SEMMNU  SEMMNS          /* num of undo structures system wide */
90 #define SEMMAP  SEMMNS          /* # of entries in semaphore map */
91 #define SEMUSZ  20		/* sizeof struct sem_undo */
92 
93 
94 #endif /* _UAPI_LINUX_SEM_H */
95