xref: /openbmc/linux/include/linux/sem.h (revision 7490ca1e)
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 */
23 struct 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. */
38 struct 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. */
45 union semun {
46 	int val;			/* value for SETVAL */
47 	struct semid_ds __user *buf;	/* buffer for IPC_STAT & IPC_SET */
48 	unsigned short __user *array;	/* array for GETALL & SETALL */
49 	struct seminfo __user *__buf;	/* buffer for IPC_INFO */
50 	void __user *__pad;
51 };
52 
53 struct  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 #include <linux/atomic.h>
81 #include <linux/rcupdate.h>
82 #include <linux/cache.h>
83 
84 struct task_struct;
85 
86 /* One sem_array data structure for each set of semaphores in the system. */
87 struct sem_array {
88 	struct kern_ipc_perm	____cacheline_aligned_in_smp
89 				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 list_head	sem_pending;	/* pending operations to be processed */
94 	struct list_head	list_id;	/* undo requests on this array */
95 	int			sem_nsems;	/* no. of semaphores in array */
96 	int			complex_count;	/* pending complex operations */
97 };
98 
99 #ifdef CONFIG_SYSVIPC
100 
101 struct sysv_sem {
102 	struct sem_undo_list *undo_list;
103 };
104 
105 extern int copy_semundo(unsigned long clone_flags, struct task_struct *tsk);
106 extern void exit_sem(struct task_struct *tsk);
107 
108 #else
109 
110 struct sysv_sem {
111 	/* empty */
112 };
113 
114 static inline int copy_semundo(unsigned long clone_flags, struct task_struct *tsk)
115 {
116 	return 0;
117 }
118 
119 static inline void exit_sem(struct task_struct *tsk)
120 {
121 	return;
122 }
123 #endif
124 
125 #endif /* __KERNEL__ */
126 
127 #endif /* _LINUX_SEM_H */
128