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#ifndef _LINUX_SEM_H
#define _LINUX_SEM_H

#include <linux/ipc.h>
#include <asm/atomic.h>

/* semop flags */
#define SEM_UNDO        0x1000  /* undo the operation on exit */

/* semctl Command Definitions. */
#define GETPID  11       /* get sempid */
#define GETVAL  12       /* get semval */
#define GETALL  13       /* get all semval's */
#define GETNCNT 14       /* get semncnt */
#define GETZCNT 15       /* get semzcnt */
#define SETVAL  16       /* set semval */
#define SETALL  17       /* set all semval's */

/* ipcs ctl cmds */
#define SEM_STAT 18
#define SEM_INFO 19

/* Obsolete, used only for backwards compatibility and libc5 compiles */
struct semid_ds {
        struct ipc_perm sem_perm;               /* permissions .. see ipc.h */
        __kernel_time_t sem_otime;              /* last semop time */
        __kernel_time_t sem_ctime;              /* last change time */
        struct sem      *sem_base;              /* ptr to first semaphore in array */
        struct sem_queue *sem_pending;          /* pending operations to be processed */
        struct sem_queue **sem_pending_last;    /* last pending operation */
        struct sem_undo *undo;                  /* undo requests on this array */
        unsigned short  sem_nsems;              /* no. of semaphores in array */
};

/* Include the definition of semid64_ds */
#include <asm/sembuf.h>

/* semop system calls takes an array of these. */
struct sembuf {
        unsigned short  sem_num;        /* semaphore index in array */
        short           sem_op;         /* semaphore operation */
        short           sem_flg;        /* operation flags */
};

/* arg for semctl system calls. */
union semun {
        int val;                        /* value for SETVAL */
        struct semid_ds *buf;           /* buffer for IPC_STAT & IPC_SET */
        unsigned short *array;          /* array for GETALL & SETALL */
        struct seminfo *__buf;          /* buffer for IPC_INFO */
        void *__pad;
};

struct  seminfo {
        int semmap;
        int semmni;
        int semmns;
        int semmnu;
        int semmsl;
        int semopm;
        int semume;
        int semusz;
        int semvmx;
        int semaem;
};

#define SEMMNI  128             /* <= IPCMNI  max # of semaphore identifiers */
#define SEMMSL  250             /* <= 8 000 max num of semaphores per id */
#define SEMMNS  (SEMMNI*SEMMSL) /* <= INT_MAX max # of semaphores in system */
#define SEMOPM  32              /* <= 1 000 max num of ops per semop call */
#define SEMVMX  32767           /* <= 32767 semaphore maximum value */
#define SEMAEM  SEMVMX          /* adjust on exit max value */

/* unused */
#define SEMUME  SEMOPM          /* max num of undo entries per process */
#define SEMMNU  SEMMNS          /* num of undo structures system wide */
#define SEMMAP  SEMMNS          /* # of entries in semaphore map */
#define SEMUSZ  20              /* sizeof struct sem_undo */

#ifdef __KERNEL__

/* One semaphore structure for each semaphore in the system. */
struct sem {
        int     semval;         /* current value */
        int     sempid;         /* pid of last operation */
};

/* One sem_array data structure for each set of semaphores in the system. */
struct sem_array {
        struct kern_ipc_perm    sem_perm;       /* permissions .. see ipc.h */
        time_t                  sem_otime;      /* last semop time */
        time_t                  sem_ctime;      /* last change time */
        struct sem              *sem_base;      /* ptr to first semaphore in array */
        struct sem_queue        *sem_pending;   /* pending operations to be processed */
        struct sem_queue        **sem_pending_last; /* last pending operation */
        struct sem_undo         *undo;          /* undo requests on this array */
        unsigned long           sem_nsems;      /* no. of semaphores in array */
};

/* One queue for each sleeping process in the system. */
struct sem_queue {
        struct sem_queue *      next;    /* next entry in the queue */
        struct sem_queue **     prev;    /* previous entry in the queue, *(q->prev) == q */
        struct task_struct*     sleeper; /* this process */
        struct sem_undo *       undo;    /* undo structure */
        int                     pid;     /* process id of requesting process */
        int                     status;  /* completion status of operation */
        struct sem_array *      sma;     /* semaphore array for operations */
        int                     id;      /* internal sem id */
        struct sembuf *         sops;    /* array of pending operations */
        int                     nsops;   /* number of operations */
};

/* Each task has a list of undo requests. They are executed automatically
 * when the process exits.
 */
struct sem_undo {
        struct sem_undo *       proc_next;      /* next entry on this process */
        struct sem_undo *       id_next;        /* next entry on this semaphore set */
        int                     semid;          /* semaphore set identifier */
        short *                 semadj;         /* array of adjustments, one per semaphore */
};

/* sem_undo_list controls shared access to the list of sem_undo structures
 * that may be shared among all a CLONE_SYSVSEM task group.
 */
struct sem_undo_list {
        atomic_t        refcnt;
        spinlock_t      lock;
        struct sem_undo *proc_list;
};

struct sysv_sem {
        struct sem_undo_list *undo_list;
};

asmlinkage long sys_semget (key_t key, int nsems, int semflg);
asmlinkage long sys_semop (int semid, struct sembuf __user *sops, unsigned nsops);
asmlinkage long sys_semctl (int semid, int semnum, int cmd, union semun arg);
asmlinkage long sys_semtimedop(int semid, struct sembuf __user *sops,
                        unsigned nsops, const struct timespec __user *timeout);

void exit_sem(struct task_struct *p);

#endif /* __KERNEL__ */

#endif /* _LINUX_SEM_H */