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/* $Id: shmparam.h,v 1.3 1995/11/25 02:32:42 davem Exp $ */
#ifndef _ASMSPARC_SHMPARAM_H
#define _ASMSPARC_SHMPARAM_H
/* address range for shared memory attaches if no address passed to shmat() */
#define SHM_RANGE_START 0x10000000
#define SHM_RANGE_END 0x20000000
/*
* Format of a swap-entry for shared memory pages currently out in
* swap space (see also mm/swap.c).
*
* SWP_TYPE = SHM_SWP_TYPE
* SWP_OFFSET is used as follows:
*
* bits 0..6 : id of shared memory segment page belongs to (SHM_ID)
* bits 7..21: index of page within shared memory segment (SHM_IDX)
* (actually fewer bits get used since SHMMAX is so low)
*/
/*
* Keep _SHM_ID_BITS as low as possible since SHMMNI depends on it and
* there is a static array of size SHMMNI.
*/
#define _SHM_ID_BITS 7
#define SHM_ID_MASK ((1<<_SHM_ID_BITS)-1)
#define SHM_IDX_SHIFT (_SHM_ID_BITS)
#define _SHM_IDX_BITS 15
#define SHM_IDX_MASK ((1<<_SHM_IDX_BITS)-1)
/*
* _SHM_ID_BITS + _SHM_IDX_BITS must be <= 24 on the i386 and
* SHMMAX <= (PAGE_SIZE << _SHM_IDX_BITS).
*/
#define SHMMAX (1024 * 1024) /* max shared seg size (bytes) */
#define SHMMIN 1 /* really PAGE_SIZE */ /* min shared seg size (bytes) */
#define SHMMNI (1<<_SHM_ID_BITS) /* max num of segs system wide */
#define SHMALL /* max shm system wide (pages) */ \
(1<<(_SHM_IDX_BITS+_SHM_ID_BITS))
#define SHMLBA PAGE_SIZE /* attach addr a multiple of this */
#define SHMSEG SHMMNI /* max shared segs per process */
#endif /* _ASMSPARC_SHMPARAM_H */
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