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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _LINUX_SEM_H
2#define _LINUX_SEM_H
3
4#include <linux/ipc.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07005
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 __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
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__
David Woodhouse8ffbc752006-04-25 14:55:13 +010080#include <asm/atomic.h>
Manfred Spraul380af1b2008-07-25 01:48:06 -070081#include <linux/rcupdate.h>
Manfred Spraul31a7c472010-05-26 14:43:42 -070082#include <linux/cache.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070083
Tim Schmielau8c65b4a2005-11-07 00:59:43 -080084struct task_struct;
85
Linus Torvalds1da177e2005-04-16 15:20:36 -070086/* One semaphore structure for each semaphore in the system. */
87struct sem {
88 int semval; /* current value */
89 int sempid; /* pid of last operation */
Manfred Spraulb97e8202009-12-15 16:47:32 -080090 struct list_head sem_pending; /* pending single-sop operations */
Linus Torvalds1da177e2005-04-16 15:20:36 -070091};
92
93/* One sem_array data structure for each set of semaphores in the system. */
94struct sem_array {
Manfred Spraul31a7c472010-05-26 14:43:42 -070095 struct kern_ipc_perm ____cacheline_aligned_in_smp
96 sem_perm; /* permissions .. see ipc.h */
Linus Torvalds1da177e2005-04-16 15:20:36 -070097 time_t sem_otime; /* last semop time */
98 time_t sem_ctime; /* last change time */
99 struct sem *sem_base; /* ptr to first semaphore in array */
Manfred Spraula1193f82008-07-25 01:48:06 -0700100 struct list_head sem_pending; /* pending operations to be processed */
Manfred Spraul4daa28f2008-07-25 01:48:04 -0700101 struct list_head list_id; /* undo requests on this array */
Manfred Spraulb97e8202009-12-15 16:47:32 -0800102 int sem_nsems; /* no. of semaphores in array */
103 int complex_count; /* pending complex operations */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104};
105
106/* One queue for each sleeping process in the system. */
107struct sem_queue {
Manfred Spraulb97e8202009-12-15 16:47:32 -0800108 struct list_head simple_list; /* queue of pending operations */
Manfred Spraula1193f82008-07-25 01:48:06 -0700109 struct list_head list; /* queue of pending operations */
110 struct task_struct *sleeper; /* this process */
111 struct sem_undo *undo; /* undo structure */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 int pid; /* process id of requesting process */
113 int status; /* completion status of operation */
Manfred Spraula1193f82008-07-25 01:48:06 -0700114 struct sembuf *sops; /* array of pending operations */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 int nsops; /* number of operations */
116 int alter; /* does the operation alter the array? */
117};
118
119/* Each task has a list of undo requests. They are executed automatically
120 * when the process exits.
121 */
122struct sem_undo {
Manfred Spraul380af1b2008-07-25 01:48:06 -0700123 struct list_head list_proc; /* per-process list: all undos from one process. */
124 /* rcu protected */
125 struct rcu_head rcu; /* rcu struct for sem_undo() */
126 struct sem_undo_list *ulp; /* sem_undo_list for the process */
Manfred Spraul4daa28f2008-07-25 01:48:04 -0700127 struct list_head list_id; /* per semaphore array list: all undos for one array */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 int semid; /* semaphore set identifier */
129 short * semadj; /* array of adjustments, one per semaphore */
130};
131
132/* sem_undo_list controls shared access to the list of sem_undo structures
133 * that may be shared among all a CLONE_SYSVSEM task group.
134 */
135struct sem_undo_list {
Manfred Spraul4daa28f2008-07-25 01:48:04 -0700136 atomic_t refcnt;
137 spinlock_t lock;
138 struct list_head list_proc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139};
140
141struct sysv_sem {
142 struct sem_undo_list *undo_list;
143};
144
145#ifdef CONFIG_SYSVIPC
146
147extern int copy_semundo(unsigned long clone_flags, struct task_struct *tsk);
148extern void exit_sem(struct task_struct *tsk);
149
150#else
151static inline int copy_semundo(unsigned long clone_flags, struct task_struct *tsk)
152{
153 return 0;
154}
155
156static inline void exit_sem(struct task_struct *tsk)
157{
158 return;
159}
160#endif
161
162#endif /* __KERNEL__ */
163
164#endif /* _LINUX_SEM_H */