1/*
 2 * Copyright (C) 2004 Fujitsu Siemens Computers GmbH
 3 * Licensed under the GPL
 4 *
 5 * Author: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
 6 */
 7
 8#ifndef __ASM_LDT_H
 9#define __ASM_LDT_H
10
11#include <linux/mutex.h>
12#include <asm/ldt.h>
13
14#define LDT_PAGES_MAX \
15	((LDT_ENTRIES * LDT_ENTRY_SIZE)/PAGE_SIZE)
16#define LDT_ENTRIES_PER_PAGE \
17	(PAGE_SIZE/LDT_ENTRY_SIZE)
18#define LDT_DIRECT_ENTRIES \
19	((LDT_PAGES_MAX*sizeof(void *))/LDT_ENTRY_SIZE)
20
21struct ldt_entry {
22	__u32 a;
23	__u32 b;
24};
25
26typedef struct uml_ldt {
27	int entry_count;
28	struct mutex lock;
29	union {
30		struct ldt_entry * pages[LDT_PAGES_MAX];
31		struct ldt_entry entries[LDT_DIRECT_ENTRIES];
32	} u;
33} uml_ldt_t;
34
35#define LDT_entry_a(info) \
36	((((info)->base_addr & 0x0000ffff) << 16) | ((info)->limit & 0x0ffff))
37
38#define LDT_entry_b(info) \
39	(((info)->base_addr & 0xff000000) | \
40	(((info)->base_addr & 0x00ff0000) >> 16) | \
41	((info)->limit & 0xf0000) | \
42	(((info)->read_exec_only ^ 1) << 9) | \
43	((info)->contents << 10) | \
44	(((info)->seg_not_present ^ 1) << 15) | \
45	((info)->seg_32bit << 22) | \
46	((info)->limit_in_pages << 23) | \
47	((info)->useable << 20) | \
48	0x7000)
49
50#define _LDT_empty(info) (\
51	(info)->base_addr	== 0	&& \
52	(info)->limit		== 0	&& \
53	(info)->contents	== 0	&& \
54	(info)->read_exec_only	== 1	&& \
55	(info)->seg_32bit	== 0	&& \
56	(info)->limit_in_pages	== 0	&& \
57	(info)->seg_not_present	== 1	&& \
58	(info)->useable		== 0	)
59
60#ifdef CONFIG_X86_64
61#define LDT_empty(info) (_LDT_empty(info) && ((info)->lm == 0))
62#else
63#define LDT_empty(info) (_LDT_empty(info))
64#endif
65
66struct uml_arch_mm_context {
67	uml_ldt_t ldt;
68};
69
70#endif