#ifndef _LINUX_SHM_H_
  #define _LINUX_SHM_H_
  
  #include <linux/ipc.h>
  #include <linux/errno.h>

  #ifdef __KERNEL__

  #include <asm/page.h>

  #else
  #include <unistd.h>
  #endif

  
  /*
   * SHMMAX, SHMMNI and SHMALL are upper limits are defaults which can
   * be increased by sysctl
   */
  
  #define SHMMAX 0x2000000		 /* max shared seg size (bytes) */
  #define SHMMIN 1			 /* min shared seg size (bytes) */
  #define SHMMNI 4096			 /* max num of segs system wide */

  #ifdef __KERNEL__

  #define SHMALL (SHMMAX/PAGE_SIZE*(SHMMNI/16)) /* max shm system wide (pages) */

  #else
  #define SHMALL (SHMMAX/getpagesize()*(SHMMNI/16))
  #endif

  #define SHMSEG SHMMNI			 /* max shared segs per process */

  #ifdef __KERNEL__

  #include <asm/shmparam.h>

  #endif

  
  /* Obsolete, used only for backwards compatibility and libc5 compiles */
  struct shmid_ds {
  	struct ipc_perm		shm_perm;	/* operation perms */
  	int			shm_segsz;	/* size of segment (bytes) */
  	__kernel_time_t		shm_atime;	/* last attach time */
  	__kernel_time_t		shm_dtime;	/* last detach time */
  	__kernel_time_t		shm_ctime;	/* last change time */
  	__kernel_ipc_pid_t	shm_cpid;	/* pid of creator */
  	__kernel_ipc_pid_t	shm_lpid;	/* pid of last operator */
  	unsigned short		shm_nattch;	/* no. of current attaches */
  	unsigned short 		shm_unused;	/* compatibility */
  	void 			*shm_unused2;	/* ditto - used by DIPC */
  	void			*shm_unused3;	/* unused */
  };
  
  /* Include the definition of shmid64_ds and shminfo64 */
  #include <asm/shmbuf.h>
  
  /* permission flag for shmget */
  #define SHM_R		0400	/* or S_IRUGO from <linux/stat.h> */
  #define SHM_W		0200	/* or S_IWUGO from <linux/stat.h> */
  
  /* mode for attach */
  #define	SHM_RDONLY	010000	/* read-only access */
  #define	SHM_RND		020000	/* round attach address to SHMLBA boundary */
  #define	SHM_REMAP	040000	/* take-over region on attach */
  #define	SHM_EXEC	0100000	/* execution access */
  
  /* super user shmctl commands */
  #define SHM_LOCK 	11
  #define SHM_UNLOCK 	12
  
  /* ipcs ctl commands */
  #define SHM_STAT 	13
  #define SHM_INFO 	14
  
  /* Obsolete, used only for backwards compatibility */
  struct	shminfo {
  	int shmmax;
  	int shmmin;
  	int shmmni;
  	int shmseg;
  	int shmall;
  };
  
  struct shm_info {
  	int used_ids;
  	unsigned long shm_tot;	/* total allocated shm */
  	unsigned long shm_rss;	/* total resident shm */
  	unsigned long shm_swp;	/* total swapped shm */
  	unsigned long swap_attempts;
  	unsigned long swap_successes;
  };
  
  #ifdef __KERNEL__
  struct shmid_kernel /* private to the kernel */
  {	
  	struct kern_ipc_perm	shm_perm;
  	struct file *		shm_file;

  	unsigned long		shm_nattch;
  	unsigned long		shm_segsz;
  	time_t			shm_atim;
  	time_t			shm_dtim;
  	time_t			shm_ctim;
  	pid_t			shm_cprid;
  	pid_t			shm_lprid;
  	struct user_struct	*mlock_user;
  };
  
  /* shm_mode upper byte flags */
  #define	SHM_DEST	01000	/* segment will be destroyed on last detach */
  #define SHM_LOCKED      02000   /* segment will not be swapped */
  #define SHM_HUGETLB     04000   /* segment will use huge TLB pages */

  #define SHM_NORESERVE   010000  /* don't check for reservations */

  
  #ifdef CONFIG_SYSVIPC
  long do_shmat(int shmid, char __user *shmaddr, int shmflg, unsigned long *addr);

  extern int is_file_shm_hugepages(struct file *file);

  #else
  static inline long do_shmat(int shmid, char __user *shmaddr,
  				int shmflg, unsigned long *addr)
  {
  	return -ENOSYS;
  }

  static inline int is_file_shm_hugepages(struct file *file)
  {
  	return 0;
  }

  #endif
  
  #endif /* __KERNEL__ */
  
  #endif /* _LINUX_SHM_H_ */