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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _LINUX_SHM_H_
2#define _LINUX_SHM_H_
3
Jack Millerab602f72014-08-08 14:23:19 -07004#include <linux/list.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07005#include <asm/page.h>
David Howells607ca462012-10-13 10:46:48 +01006#include <uapi/linux/shm.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07007#include <asm/shmparam.h>
Manfred Spraul060028b2014-06-06 14:37:42 -07008
Linus Torvalds1da177e2005-04-16 15:20:36 -07009struct shmid_kernel /* private to the kernel */
10{
11 struct kern_ipc_perm shm_perm;
Manfred Spraul239521f2014-01-27 17:07:04 -080012 struct file *shm_file;
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 unsigned long shm_nattch;
14 unsigned long shm_segsz;
15 time_t shm_atim;
16 time_t shm_dtim;
17 time_t shm_ctim;
18 pid_t shm_cprid;
19 pid_t shm_lprid;
20 struct user_struct *mlock_user;
Vasiliy Kulikov5774ed02011-07-29 03:55:31 +040021
22 /* The task created the shm object. NULL if the task is dead. */
23 struct task_struct *shm_creator;
Jack Millerab602f72014-08-08 14:23:19 -070024 struct list_head shm_clist; /* list by creator */
Linus Torvalds1da177e2005-04-16 15:20:36 -070025};
26
27/* shm_mode upper byte flags */
28#define SHM_DEST 01000 /* segment will be destroyed on last detach */
29#define SHM_LOCKED 02000 /* segment will not be swapped */
30#define SHM_HUGETLB 04000 /* segment will use huge TLB pages */
Badari Pulavartybf8f9722005-11-07 00:59:27 -080031#define SHM_NORESERVE 010000 /* don't check for reservations */
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
Andi Kleen42d73952012-12-11 16:01:34 -080033/* Bits [26:31] are reserved */
34
35/*
36 * When SHM_HUGETLB is set bits [26:31] encode the log2 of the huge page size.
37 * This gives us 6 bits, which is enough until someone invents 128 bit address
38 * spaces.
39 *
40 * Assume these are all power of twos.
41 * When 0 use the default page size.
42 */
43#define SHM_HUGE_SHIFT 26
44#define SHM_HUGE_MASK 0x3f
45#define SHM_HUGE_2MB (21 << SHM_HUGE_SHIFT)
46#define SHM_HUGE_1GB (30 << SHM_HUGE_SHIFT)
47
Linus Torvalds1da177e2005-04-16 15:20:36 -070048#ifdef CONFIG_SYSVIPC
Jack Millerab602f72014-08-08 14:23:19 -070049struct sysv_shm {
50 struct list_head shm_clist;
51};
52
Will Deacon079a96a2012-07-30 14:42:38 -070053long do_shmat(int shmid, char __user *shmaddr, int shmflg, unsigned long *addr,
54 unsigned long shmlba);
Jack Miller2f137d62014-08-08 14:23:23 -070055int is_file_shm_hugepages(struct file *file);
Jack Millerab602f72014-08-08 14:23:19 -070056void exit_shm(struct task_struct *task);
57#define shm_init_task(task) INIT_LIST_HEAD(&(task)->sysvshm.shm_clist)
Linus Torvalds1da177e2005-04-16 15:20:36 -070058#else
Jack Millerab602f72014-08-08 14:23:19 -070059struct sysv_shm {
60 /* empty */
61};
62
Linus Torvalds1da177e2005-04-16 15:20:36 -070063static inline long do_shmat(int shmid, char __user *shmaddr,
Will Deacon079a96a2012-07-30 14:42:38 -070064 int shmflg, unsigned long *addr,
65 unsigned long shmlba)
Linus Torvalds1da177e2005-04-16 15:20:36 -070066{
67 return -ENOSYS;
68}
Adam Litke516dffd2007-03-01 15:46:08 -080069static inline int is_file_shm_hugepages(struct file *file)
70{
71 return 0;
72}
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -070073static inline void exit_shm(struct task_struct *task)
74{
75}
Jack Millerab602f72014-08-08 14:23:19 -070076static inline void shm_init_task(struct task_struct *task)
77{
78}
Linus Torvalds1da177e2005-04-16 15:20:36 -070079#endif
80
Linus Torvalds1da177e2005-04-16 15:20:36 -070081#endif /* _LINUX_SHM_H_ */