1#ifndef _LINUX_SEM_H
2#define _LINUX_SEM_H
3
4#include <linux/ipc.h>
5
6/* semop flags */
7#define SEM_UNDO        0x1000  /* undo the operation on exit */
8
9/* semctl Command Definitions. */
10#define GETPID  11       /* get sempid */
11#define GETVAL  12       /* get semval */
12#define GETALL  13       /* get all semval's */
13#define GETNCNT 14       /* get semncnt */
14#define GETZCNT 15       /* get semzcnt */
15#define SETVAL  16       /* set semval */
16#define SETALL  17       /* set all semval's */
17
18/* ipcs ctl cmds */
19#define SEM_STAT 18
20#define SEM_INFO 19
21
22/* Obsolete, used only for backwards compatibility and libc5 compiles */
23struct semid_ds {
24	struct ipc_perm	sem_perm;		/* permissions .. see ipc.h */
25	__kernel_time_t	sem_otime;		/* last semop time */
26	__kernel_time_t	sem_ctime;		/* last change time */
27	struct sem	*sem_base;		/* ptr to first semaphore in array */
28	struct sem_queue *sem_pending;		/* pending operations to be processed */
29	struct sem_queue **sem_pending_last;	/* last pending operation */
30	struct sem_undo	*undo;			/* undo requests on this array */
31	unsigned short	sem_nsems;		/* no. of semaphores in array */
32};
33
34/* Include the definition of semid64_ds */
35#include <asm/sembuf.h>
36
37/* semop system calls takes an array of these. */
38struct sembuf {
39	unsigned short  sem_num;	/* semaphore index in array */
40	short		sem_op;		/* semaphore operation */
41	short		sem_flg;	/* operation flags */
42};
43
44/* arg for semctl system calls. */
45union semun {
46	int val;			/* value for SETVAL */
47	struct semid_ds *buf;		/* buffer for IPC_STAT & IPC_SET */
48	unsigned short *array;		/* array for GETALL & SETALL */
49	struct seminfo *__buf;		/* buffer for IPC_INFO */
50	void *__pad;
51};
52
53struct  seminfo {
54	int semmap;
55	int semmni;
56	int semmns;
57	int semmnu;
58	int semmsl;
59	int semopm;
60	int semume;
61	int semusz;
62	int semvmx;
63	int semaem;
64};
65
66#define SEMMNI  128             /* <= IPCMNI  max # of semaphore identifiers */
67#define SEMMSL  250             /* <= 8 000 max num of semaphores per id */
68#define SEMMNS  (SEMMNI*SEMMSL) /* <= INT_MAX max # of semaphores in system */
69#define SEMOPM  32	        /* <= 1 000 max num of ops per semop call */
70#define SEMVMX  32767           /* <= 32767 semaphore maximum value */
71#define SEMAEM  SEMVMX          /* adjust on exit max value */
72
73/* unused */
74#define SEMUME  SEMOPM          /* max num of undo entries per process */
75#define SEMMNU  SEMMNS          /* num of undo structures system wide */
76#define SEMMAP  SEMMNS          /* # of entries in semaphore map */
77#define SEMUSZ  20		/* sizeof struct sem_undo */
78
79#ifdef __KERNEL__
80
81/* One semaphore structure for each semaphore in the system. */
82struct sem {
83	int	semval;		/* current value */
84	int	sempid;		/* pid of last operation */
85};
86
87/* One sem_array data structure for each set of semaphores in the system. */
88struct sem_array {
89	struct kern_ipc_perm	sem_perm;	/* permissions .. see ipc.h */
90	time_t			sem_otime;	/* last semop time */
91	time_t			sem_ctime;	/* last change time */
92	struct sem		*sem_base;	/* ptr to first semaphore in array */
93	struct sem_queue	*sem_pending;	/* pending operations to be processed */
94	struct sem_queue	**sem_pending_last; /* last pending operation */
95	struct sem_undo		*undo;		/* undo requests on this array */
96	unsigned long		sem_nsems;	/* no. of semaphores in array */
97};
98
99/* One queue for each sleeping process in the system. */
100struct sem_queue {
101	struct sem_queue *	next;	 /* next entry in the queue */
102	struct sem_queue **	prev;	 /* previous entry in the queue, *(q->prev) == q */
103	struct task_struct*	sleeper; /* this process */
104	struct sem_undo *	undo;	 /* undo structure */
105	int    			pid;	 /* process id of requesting process */
106	int    			status;	 /* completion status of operation */
107	struct sem_array *	sma;	 /* semaphore array for operations */
108	int			id;	 /* internal sem id */
109	struct sembuf *		sops;	 /* array of pending operations */
110	int			nsops;	 /* number of operations */
111	int			alter;	 /* operation will alter semaphore */
112};
113
114/* Each task has a list of undo requests. They are executed automatically
115 * when the process exits.
116 */
117struct sem_undo {
118	struct sem_undo *	proc_next;	/* next entry on this process */
119	struct sem_undo *	id_next;	/* next entry on this semaphore set */
120	int			semid;		/* semaphore set identifier */
121	short *			semadj;		/* array of adjustments, one per semaphore */
122};
123
124asmlinkage long sys_semget (key_t key, int nsems, int semflg);
125asmlinkage long sys_semop (int semid, struct sembuf *sops, unsigned nsops);
126asmlinkage long sys_semctl (int semid, int semnum, int cmd, union semun arg);
127
128#endif /* __KERNEL__ */
129
130#endif /* _LINUX_SEM_H */
131