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      1 #ifndef _LINUX_SHM_H_
      2 #define _LINUX_SHM_H_
      3 
      4 #include <linux/ipc.h>
      5 #include <linux/errno.h>
      6 #include <asm/page.h>
      7 
      8 /*
      9  * SHMMAX, SHMMNI and SHMALL are upper limits are defaults which can
     10  * be increased by sysctl
     11  */
     12 
     13 #define SHMMAX 0x2000000		 /* max shared seg size (bytes) */
     14 #define SHMMIN 1			 /* min shared seg size (bytes) */
     15 #define SHMMNI 4096			 /* max num of segs system wide */
     16 #define SHMALL (SHMMAX/PAGE_SIZE*(SHMMNI/16)) /* max shm system wide (pages) */
     17 #define SHMSEG SHMMNI			 /* max shared segs per process */
     18 
     19 #include <asm/shmparam.h>
     20 
     21 /* Obsolete, used only for backwards compatibility and libc5 compiles */
     22 struct shmid_ds {
     23 	struct ipc_perm		shm_perm;	/* operation perms */
     24 	int			shm_segsz;	/* size of segment (bytes) */
     25 	__kernel_time_t		shm_atime;	/* last attach time */
     26 	__kernel_time_t		shm_dtime;	/* last detach time */
     27 	__kernel_time_t		shm_ctime;	/* last change time */
     28 	__kernel_ipc_pid_t	shm_cpid;	/* pid of creator */
     29 	__kernel_ipc_pid_t	shm_lpid;	/* pid of last operator */
     30 	unsigned short		shm_nattch;	/* no. of current attaches */
     31 	unsigned short 		shm_unused;	/* compatibility */
     32 	void 			*shm_unused2;	/* ditto - used by DIPC */
     33 	void			*shm_unused3;	/* unused */
     34 };
     35 
     36 /* Include the definition of shmid64_ds and shminfo64 */
     37 #include <asm/shmbuf.h>
     38 
     39 /* permission flag for shmget */
     40 #define SHM_R		0400	/* or S_IRUGO from <linux/stat.h> */
     41 #define SHM_W		0200	/* or S_IWUGO from <linux/stat.h> */
     42 
     43 /* mode for attach */
     44 #define	SHM_RDONLY	010000	/* read-only access */
     45 #define	SHM_RND		020000	/* round attach address to SHMLBA boundary */
     46 #define	SHM_REMAP	040000	/* take-over region on attach */
     47 #define	SHM_EXEC	0100000	/* execution access */
     48 
     49 /* super user shmctl commands */
     50 #define SHM_LOCK 	11
     51 #define SHM_UNLOCK 	12
     52 
     53 /* ipcs ctl commands */
     54 #define SHM_STAT 	13
     55 #define SHM_INFO 	14
     56 
     57 /* Obsolete, used only for backwards compatibility */
     58 struct	shminfo {
     59 	int shmmax;
     60 	int shmmin;
     61 	int shmmni;
     62 	int shmseg;
     63 	int shmall;
     64 };
     65 
     66 struct shm_info {
     67 	int used_ids;
     68 	unsigned long shm_tot;	/* total allocated shm */
     69 	unsigned long shm_rss;	/* total resident shm */
     70 	unsigned long shm_swp;	/* total swapped shm */
     71 	unsigned long swap_attempts;
     72 	unsigned long swap_successes;
     73 };
     74 
     75 #ifdef __KERNEL__
     76 struct shmid_kernel /* private to the kernel */
     77 {
     78 	struct kern_ipc_perm	shm_perm;
     79 	struct file *		shm_file;
     80 	int			id;
     81 	unsigned long		shm_nattch;
     82 	unsigned long		shm_segsz;
     83 	time_t			shm_atim;
     84 	time_t			shm_dtim;
     85 	time_t			shm_ctim;
     86 	pid_t			shm_cprid;
     87 	pid_t			shm_lprid;
     88 	struct user_struct	*mlock_user;
     89 };
     90 
     91 /* shm_mode upper byte flags */
     92 #define	SHM_DEST	01000	/* segment will be destroyed on last detach */
     93 #define SHM_LOCKED      02000   /* segment will not be swapped */
     94 #define SHM_HUGETLB     04000   /* segment will use huge TLB pages */
     95 #define SHM_NORESERVE   010000  /* don't check for reservations */
     96 
     97 #ifdef CONFIG_SYSVIPC
     98 long do_shmat(int shmid, char __user *shmaddr, int shmflg, unsigned long *addr);
     99 #else
    100 static inline long do_shmat(int shmid, char __user *shmaddr,
    101 				int shmflg, unsigned long *addr)
    102 {
    103 	return -ENOSYS;
    104 }
    105 #endif
    106 
    107 #endif /* __KERNEL__ */
    108 
    109 #endif /* _LINUX_SHM_H_ */
    110