Linux kernel mirror (for testing)
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1/* segment.h: MMU segment settings
2 *
3 * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12#ifndef _ASM_SEGMENT_H
13#define _ASM_SEGMENT_H
14
15#include <linux/config.h>
16
17#ifndef __ASSEMBLY__
18
19typedef struct {
20 unsigned long seg;
21} mm_segment_t;
22
23#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
24
25#define KERNEL_DS MAKE_MM_SEG(0xdfffffffUL)
26
27#ifdef CONFIG_MMU
28#define USER_DS MAKE_MM_SEG(TASK_SIZE - 1)
29#else
30#define USER_DS KERNEL_DS
31#endif
32
33#define get_ds() (KERNEL_DS)
34#define get_fs() (__current_thread_info->addr_limit)
35#define segment_eq(a,b) ((a).seg == (b).seg)
36#define __kernel_ds_p() segment_eq(get_fs(), KERNEL_DS)
37#define get_addr_limit() (get_fs().seg)
38
39#define set_fs(_x) \
40do { \
41 __current_thread_info->addr_limit = (_x); \
42} while(0)
43
44
45#endif /* __ASSEMBLY__ */
46#endif /* _ASM_SEGMENT_H */