LXR linux-old/include/linux/shm.h

   1#ifndef _LINUX_SHM_H_
   2#define _LINUX_SHM_H_
   3
   4#include <linux/ipc.h>
   5#include <asm/page.h>
   6
   7/*
   8 * SHMMAX, SHMMNI and SHMALL are upper limits are defaults which can
   9 * be increased by sysctl
  10 */
  11
  12#define SHMMAX 0x2000000                 /* max shared seg size (bytes) */
  13#define SHMMIN 1                         /* min shared seg size (bytes) */
  14#define SHMMNI 4096                      /* max num of segs system wide */
  15#define SHMALL (SHMMAX/PAGE_SIZE*(SHMMNI/16)) /* max shm system wide (pages) */
  16#define SHMSEG SHMMNI                    /* max shared segs per process */
  17
  18#include <asm/shmparam.h>
  19
  20/* Obsolete, used only for backwards compatibility and libc5 compiles */
  21struct shmid_ds {
  22        struct ipc_perm         shm_perm;       /* operation perms */
  23        int                     shm_segsz;      /* size of segment (bytes) */
  24        __kernel_time_t         shm_atime;      /* last attach time */
  25        __kernel_time_t         shm_dtime;      /* last detach time */
  26        __kernel_time_t         shm_ctime;      /* last change time */
  27        __kernel_ipc_pid_t      shm_cpid;       /* pid of creator */
  28        __kernel_ipc_pid_t      shm_lpid;       /* pid of last operator */
  29        unsigned short          shm_nattch;     /* no. of current attaches */
  30        unsigned short          shm_unused;     /* compatibility */
  31        void                    *shm_unused2;   /* ditto - used by DIPC */
  32        void                    *shm_unused3;   /* unused */
  33};
  34
  35/* Include the definition of shmid64_ds and shminfo64 */
  36#include <asm/shmbuf.h>
  37
  38/* permission flag for shmget */
  39#define SHM_R           0400    /* or S_IRUGO from <linux/stat.h> */
  40#define SHM_W           0200    /* or S_IWUGO from <linux/stat.h> */
  41
  42/* mode for attach */
  43#define SHM_RDONLY      010000  /* read-only access */
  44#define SHM_RND         020000  /* round attach address to SHMLBA boundary */
  45#define SHM_REMAP       040000  /* take-over region on attach */
  46
  47/* super user shmctl commands */
  48#define SHM_LOCK        11
  49#define SHM_UNLOCK      12
  50
  51/* ipcs ctl commands */
  52#define SHM_STAT        13
  53#define SHM_INFO        14
  54
  55/* Obsolete, used only for backwards compatibility */
  56struct  shminfo {
  57        int shmmax;
  58        int shmmin;
  59        int shmmni;
  60        int shmseg;
  61        int shmall;
  62};
  63
  64struct shm_info {
  65        int used_ids;
  66        unsigned long shm_tot;  /* total allocated shm */
  67        unsigned long shm_rss;  /* total resident shm */
  68        unsigned long shm_swp;  /* total swapped shm */
  69        unsigned long swap_attempts;
  70        unsigned long swap_successes;
  71};
  72
  73#ifdef __KERNEL__
  74
  75/* shm_mode upper byte flags */
  76#define SHM_DEST        01000   /* segment will be destroyed on last detach */
  77#define SHM_LOCKED      02000   /* segment will not be swapped */
  78
  79asmlinkage long sys_shmget (key_t key, size_t size, int flag);
  80asmlinkage long sys_shmat (int shmid, char *shmaddr, int shmflg, unsigned long *addr);
  81asmlinkage long sys_shmdt (char *shmaddr);
  82asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds *buf);
  83extern void shm_unuse(swp_entry_t entry, struct page *page);
  84
  85#endif /* __KERNEL__ */
  86
  87#endif /* _LINUX_SHM_H_ */
  88