Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
| 19 | typedef 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) \ |
| 40 | do { \ |
| 41 | __current_thread_info->addr_limit = (_x); \ |
| 42 | } while(0) |
| 43 | |
| 44 | |
| 45 | #endif /* __ASSEMBLY__ */ |
| 46 | #endif /* _ASM_SEGMENT_H */ |