1 #ifndef _LINUX_SHM_H_
2 #define _LINUX_SHM_H_
3
4 #include <linux/ipc.h>
5 #include <linux/errno.h>
6 #ifdef __KERNEL__
7 #include <asm/page.h>
8 #else
9 #include <unistd.h>
10 #endif
11
12 /*
13 * SHMMAX, SHMMNI and SHMALL are upper limits are defaults which can
14 * be increased by sysctl
15 */
16
17 #define SHMMAX 0x2000000 /* max shared seg size (bytes) */
18 #define SHMMIN 1 /* min shared seg size (bytes) */
19 #define SHMMNI 4096 /* max num of segs system wide */
20 #ifdef __KERNEL__
21 #define SHMALL (SHMMAX/PAGE_SIZE*(SHMMNI/16)) /* max shm system wide (pages) */
22 #else
23 #define SHMALL (SHMMAX/getpagesize()*(SHMMNI/16))
24 #endif
25 #define SHMSEG SHMMNI /* max shared segs per process */
26
27 #ifdef __KERNEL__
28 #include <asm/shmparam.h>
29 #endif
30
31 /* Obsolete, used only for backwards compatibility and libc5 compiles */
32 struct shmid_ds {
33 struct ipc_perm shm_perm; /* operation perms */
34 int shm_segsz; /* size of segment (bytes) */
35 __kernel_time_t shm_atime; /* last attach time */
36 __kernel_time_t shm_dtime; /* last detach time */
37 __kernel_time_t shm_ctime; /* last change time */
38 __kernel_ipc_pid_t shm_cpid; /* pid of creator */
39 __kernel_ipc_pid_t shm_lpid; /* pid of last operator */
40 unsigned short shm_nattch; /* no. of current attaches */
41 unsigned short shm_unused; /* compatibility */
42 void *shm_unused2; /* ditto - used by DIPC */
43 void *shm_unused3; /* unused */
44 };
45
46 /* Include the definition of shmid64_ds and shminfo64 */
47 #include <asm/shmbuf.h>
48
49 /* permission flag for shmget */
50 #define SHM_R 0400 /* or S_IRUGO from <linux/stat.h> */
51 #define SHM_W 0200 /* or S_IWUGO from <linux/stat.h> */
52
53 /* mode for attach */
54 #define SHM_RDONLY 010000 /* read-only access */
55 #define SHM_RND 020000 /* round attach address to SHMLBA boundary */
56 #define SHM_REMAP 040000 /* take-over region on attach */
57 #define SHM_EXEC 0100000 /* execution access */
58
59 /* super user shmctl commands */
60 #define SHM_LOCK 11
61 #define SHM_UNLOCK 12
62
63 /* ipcs ctl commands */
64 #define SHM_STAT 13
65 #define SHM_INFO 14
66
67 /* Obsolete, used only for backwards compatibility */
68 struct shminfo {
69 int shmmax;
70 int shmmin;
71 int shmmni;
72 int shmseg;
73 int shmall;
74 };
75
76 struct shm_info {
77 int used_ids;
78 unsigned long shm_tot; /* total allocated shm */
79 unsigned long shm_rss; /* total resident shm */
80 unsigned long shm_swp; /* total swapped shm */
81 unsigned long swap_attempts;
82 unsigned long swap_successes;
83 };
84
85 #ifdef __KERNEL__
86 struct shmid_kernel /* private to the kernel */
87 {
88 struct kern_ipc_perm shm_perm;
89 struct file * shm_file;
90 unsigned long shm_nattch;
91 unsigned long shm_segsz;
92 time_t shm_atim;
93 time_t shm_dtim;
94 time_t shm_ctim;
95 pid_t shm_cprid;
96 pid_t shm_lprid;
97 struct user_struct *mlock_user;
98
99 /* The task created the shm object. NULL if the task is dead. */
100 struct task_struct *shm_creator;
101 };
102
103 /* shm_mode upper byte flags */
104 #define SHM_DEST 01000 /* segment will be destroyed on last detach */
105 #define SHM_LOCKED 02000 /* segment will not be swapped */
106 #define SHM_HUGETLB 04000 /* segment will use huge TLB pages */
107 #define SHM_NORESERVE 010000 /* don't check for reservations */
108
109 #ifdef CONFIG_SYSVIPC
110 long do_shmat(int shmid, char __user *shmaddr, int shmflg, unsigned long *addr);
111 extern int is_file_shm_hugepages(struct file *file);
112 extern void exit_shm(struct task_struct *task);
113 #else
do_shmat(int shmid,char __user * shmaddr,int shmflg,unsigned long * addr)114 static inline long do_shmat(int shmid, char __user *shmaddr,
115 int shmflg, unsigned long *addr)
116 {
117 return -ENOSYS;
118 }
is_file_shm_hugepages(struct file * file)119 static inline int is_file_shm_hugepages(struct file *file)
120 {
121 return 0;
122 }
exit_shm(struct task_struct * task)123 static inline void exit_shm(struct task_struct *task)
124 {
125 }
126 #endif
127
128 #endif /* __KERNEL__ */
129
130 #endif /* _LINUX_SHM_H_ */
131