| 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 |  | 
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 |  | 
 | 16 | #ifndef __ASSEMBLY__ | 
 | 17 |  | 
 | 18 | typedef struct { | 
 | 19 | 	unsigned long seg; | 
 | 20 | } mm_segment_t; | 
 | 21 |  | 
 | 22 | #define MAKE_MM_SEG(s)	((mm_segment_t) { (s) }) | 
 | 23 |  | 
 | 24 | #define KERNEL_DS		MAKE_MM_SEG(0xdfffffffUL) | 
 | 25 |  | 
 | 26 | #ifdef CONFIG_MMU | 
 | 27 | #define USER_DS			MAKE_MM_SEG(TASK_SIZE - 1) | 
 | 28 | #else | 
 | 29 | #define USER_DS			KERNEL_DS | 
 | 30 | #endif | 
 | 31 |  | 
 | 32 | #define get_ds()		(KERNEL_DS) | 
 | 33 | #define get_fs()		(__current_thread_info->addr_limit) | 
 | 34 | #define segment_eq(a,b)		((a).seg == (b).seg) | 
 | 35 | #define __kernel_ds_p()		segment_eq(get_fs(), KERNEL_DS) | 
 | 36 | #define get_addr_limit()	(get_fs().seg) | 
 | 37 |  | 
 | 38 | #define set_fs(_x)					\ | 
 | 39 | do {							\ | 
 | 40 | 	__current_thread_info->addr_limit = (_x);	\ | 
 | 41 | } while(0) | 
 | 42 |  | 
 | 43 |  | 
 | 44 | #endif /* __ASSEMBLY__ */ | 
 | 45 | #endif /* _ASM_SEGMENT_H */ |