|  | /* segment.h: MMU segment settings | 
|  | * | 
|  | * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved. | 
|  | * Written by David Howells (dhowells@redhat.com) | 
|  | * | 
|  | * This program is free software; you can redistribute it and/or | 
|  | * modify it under the terms of the GNU General Public License | 
|  | * as published by the Free Software Foundation; either version | 
|  | * 2 of the License, or (at your option) any later version. | 
|  | */ | 
|  |  | 
|  | #ifndef _ASM_SEGMENT_H | 
|  | #define _ASM_SEGMENT_H | 
|  |  | 
|  |  | 
|  | #ifndef __ASSEMBLY__ | 
|  |  | 
|  | typedef struct { | 
|  | unsigned long seg; | 
|  | } mm_segment_t; | 
|  |  | 
|  | #define MAKE_MM_SEG(s)	((mm_segment_t) { (s) }) | 
|  |  | 
|  | #define KERNEL_DS		MAKE_MM_SEG(0xdfffffffUL) | 
|  |  | 
|  | #ifdef CONFIG_MMU | 
|  | #define USER_DS			MAKE_MM_SEG(TASK_SIZE - 1) | 
|  | #else | 
|  | #define USER_DS			KERNEL_DS | 
|  | #endif | 
|  |  | 
|  | #define get_ds()		(KERNEL_DS) | 
|  | #define get_fs()		(__current_thread_info->addr_limit) | 
|  | #define segment_eq(a,b)		((a).seg == (b).seg) | 
|  | #define __kernel_ds_p()		segment_eq(get_fs(), KERNEL_DS) | 
|  | #define get_addr_limit()	(get_fs().seg) | 
|  |  | 
|  | #define set_fs(_x)					\ | 
|  | do {							\ | 
|  | __current_thread_info->addr_limit = (_x);	\ | 
|  | } while(0) | 
|  |  | 
|  |  | 
|  | #endif /* __ASSEMBLY__ */ | 
|  | #endif /* _ASM_SEGMENT_H */ |