[mirror_ubuntu-zesty-kernel.git] / include / linux / shm.h

#ifndef _LINUX_SHM_H_
#define _LINUX_SHM_H_

#include <asm/page.h>
#include <uapi/linux/shm.h>
#include <asm/shmparam.h>

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 */

/* Bits [26:31] are reserved */

/*
 * When SHM_HUGETLB is set bits [26:31] encode the log2 of the huge page size.
 * This gives us 6 bits, which is enough until someone invents 128 bit address
 * spaces.
 *
 * Assume these are all power of twos.
 * When 0 use the default page size.
 */
#define SHM_HUGE_SHIFT  26
#define SHM_HUGE_MASK   0x3f
#define SHM_HUGE_2MB    (21 << SHM_HUGE_SHIFT)
#define SHM_HUGE_1GB    (30 << SHM_HUGE_SHIFT)

#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 /* _LINUX_SHM_H_ */
Commit	Line	Data
1da177e4 LT	1	#ifndef _LINUX_SHM_H_
	2	#define _LINUX_SHM_H_
	3
1da177e4	4	#include <asm/page.h>
607ca46e	5	#include <uapi/linux/shm.h>
1da177e4	6	#include <asm/shmparam.h>
060028ba	7
1da177e4 LT	8	struct shmid_kernel /* private to the kernel */
	9	{
	10	struct kern_ipc_perm shm_perm;
239521f3	11	struct file *shm_file;
1da177e4 LT	12	unsigned long shm_nattch;
	13	unsigned long shm_segsz;
	14	time_t shm_atim;
	15	time_t shm_dtim;
	16	time_t shm_ctim;
	17	pid_t shm_cprid;
	18	pid_t shm_lprid;
	19	struct user_struct *mlock_user;
5774ed01 VK	20
	21	/* The task created the shm object. NULL if the task is dead. */
	22	struct task_struct *shm_creator;
1da177e4 LT	23	};
	24
	25	/* shm_mode upper byte flags */
	26	#define SHM_DEST 01000 /* segment will be destroyed on last detach */
	27	#define SHM_LOCKED 02000 /* segment will not be swapped */
	28	#define SHM_HUGETLB 04000 /* segment will use huge TLB pages */
bf8f972d	29	#define SHM_NORESERVE 010000 /* don't check for reservations */
1da177e4	30
42d7395f AK	31	/* Bits [26:31] are reserved */
	32
	33	/*
	34	* When SHM_HUGETLB is set bits [26:31] encode the log2 of the huge page size.
	35	* This gives us 6 bits, which is enough until someone invents 128 bit address
	36	* spaces.
	37	*
	38	* Assume these are all power of twos.
	39	* When 0 use the default page size.
	40	*/
	41	#define SHM_HUGE_SHIFT 26
	42	#define SHM_HUGE_MASK 0x3f
	43	#define SHM_HUGE_2MB (21 << SHM_HUGE_SHIFT)
	44	#define SHM_HUGE_1GB (30 << SHM_HUGE_SHIFT)
	45
1da177e4	46	#ifdef CONFIG_SYSVIPC
079a96ae WD	47	long do_shmat(int shmid, char __user shmaddr, int shmflg, unsigned long addr,
079a96ae WD	48	unsigned long shmlba);
516dffdc	49	extern int is_file_shm_hugepages(struct file *file);
b34a6b1d	50	extern void exit_shm(struct task_struct *task);
1da177e4 LT	51	#else
1da177e4 LT	52	static inline long do_shmat(int shmid, char __user *shmaddr,
079a96ae WD	53	int shmflg, unsigned long *addr,
079a96ae WD	54	unsigned long shmlba)
1da177e4 LT	55	{
	56	return -ENOSYS;
	57	}
516dffdc AL	58	static inline int is_file_shm_hugepages(struct file *file)
	59	{
	60	return 0;
	61	}
b34a6b1d VK	62	static inline void exit_shm(struct task_struct *task)
	63	{
	64	}
1da177e4 LT	65	#endif
1da177e4 LT	66
1da177e4	67	#endif /* _LINUX_SHM_H_ */