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 16#ifndef __ASSEMBLY__ 17 18typedef struct { 19 unsigned long seg; 20} mm_segment_t; 21 22#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) 23 24#ifdef CONFIG_MMU 25#define USER_DS MAKE_MM_SEG(TASK_SIZE - 1) 26#define KERNEL_DS MAKE_MM_SEG(0xdfffffffUL) 27#else 28#define USER_DS MAKE_MM_SEG(memory_end) 29#define KERNEL_DS MAKE_MM_SEG(0xe0000000UL) 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) \ 39do { \ 40 __current_thread_info->addr_limit = (_x); \ 41} while(0) 42 43 44#endif /* __ASSEMBLY__ */ 45#endif /* _ASM_SEGMENT_H */ 46