shm.h revision c559cd81139f97cecad1ad91a0b2e25a5936d53 
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 */
22struct 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 */
58struct	shminfo {
59	int shmmax;
60	int shmmin;
61	int shmmni;
62	int shmseg;
63	int shmall;
64};
65
66struct 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__
76struct 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
98long do_shmat(int shmid, char __user *shmaddr, int shmflg, unsigned long *addr);
99#else
100static 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