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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#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 */
Badari Pulavartybf8f9722005-11-07 00:59:27 -080095#define SHM_NORESERVE 010000 /* don't check for reservations */
Linus Torvalds1da177e2005-04-16 15:20:36 -070096
97#ifdef CONFIG_SYSVIPC
98long do_shmat(int shmid, char __user *shmaddr, int shmflg, unsigned long *addr);
Adam Litke516dffd2007-03-01 15:46:08 -080099extern int is_file_shm_hugepages(struct file *file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100#else
101static inline long do_shmat(int shmid, char __user *shmaddr,
102 int shmflg, unsigned long *addr)
103{
104 return -ENOSYS;
105}
Adam Litke516dffd2007-03-01 15:46:08 -0800106static inline int is_file_shm_hugepages(struct file *file)
107{
108 return 0;
109}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110#endif
111
112#endif /* __KERNEL__ */
113
114#endif /* _LINUX_SHM_H_ */