aboutsummaryrefslogtreecommitdiffstats
path: root/include/linux/shm.h
blob: edd086883ccbed5a84f2d44e0212d06b1af315a4 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
#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;

	/* The task created the shm object.  NULL if the task is dead. */
	struct task_struct	*shm_creator;
};

/* 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,
	      unsigned long shmlba);
extern int is_file_shm_hugepages(struct file *file);
extern void exit_shm(struct task_struct *task);
#else
static inline long do_shmat(int shmid, char __user *shmaddr,
			    int shmflg, unsigned long *addr,
			    unsigned long shmlba)
{
	return -ENOSYS;
}
static inline int is_file_shm_hugepages(struct file *file)
{
	return 0;
}
static inline void exit_shm(struct task_struct *task)
{
}
#endif

#endif /* __KERNEL__ */

#endif /* _LINUX_SHM_H_ */