blob: f20fd19a6649280a9c16899fea42f615e053b7d5 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
|
/* $Id$
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* XXX These are obviously wrong for an 64-bit OS, let's see how we divide
* the address space later ...
*/
#ifndef _ASM_SHMPARAM_H
#define _ASM_SHMPARAM_H
/* address range for shared memory attaches if no address passed to shmat() */
#define SHM_RANGE_START 0x50000000
#define SHM_RANGE_END 0x60000000
/*
* 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 0x2000000 /* max shared seg size (bytes) */
/* Try not to change the default shipped SHMMAX - people rely on it */
#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))
/*
* This constant is very large but the ABI in it's wisdom says ...
*/
#define SHMLBA 0x40000 /* attach addr a multiple of this */
#define SHMSEG SHMMNI /* max shared segs per process */
#endif /* _ASM_SHMPARAM_H */
|
