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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
do_shmat(int shmid,char __user * shmaddr,int shmflg,unsigned long * addr)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