1/*
2 * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28/*
29 * @OSF_COPYRIGHT@
30 */
31/*
32 * Mach Operating System
33 * Copyright (c) 1991,1990 Carnegie Mellon University
34 * All Rights Reserved.
35 *
36 * Permission to use, copy, modify and distribute this software and its
37 * documentation is hereby granted, provided that both the copyright
38 * notice and this permission notice appear in all copies of the
39 * software, derivative works or modified versions, and any portions
40 * thereof, and that both notices appear in supporting documentation.
41 *
42 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
43 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
44 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
45 *
46 * Carnegie Mellon requests users of this software to return to
47 *
48 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
49 *  School of Computer Science
50 *  Carnegie Mellon University
51 *  Pittsburgh PA 15213-3890
52 *
53 * any improvements or extensions that they make and grant Carnegie Mellon
54 * the rights to redistribute these changes.
55 */
56
57/*
58 */
59
60#ifndef	_I386_MP_DESC_H_
61#define	_I386_MP_DESC_H_
62
63#include <mach_kdb.h>
64#include <sys/cdefs.h>
65
66__BEGIN_DECLS
67
68/*
69 * Multiprocessor i386/i486 systems use a separate copy of the
70 * GDT, IDT, LDT, and kernel TSS per processor.  The first three
71 * are separate to avoid lock contention: the i386 uses locked
72 * memory cycles to access the descriptor tables.  The TSS is
73 * separate since each processor needs its own kernel stack,
74 * and since using a TSS marks it busy.
75 */
76
77#include <i386/seg.h>
78#include <i386/tss.h>
79
80/*
81 * The descriptor tables are together in a structure
82 * allocated one per processor (except for the boot processor).
83 * Note that dbtss could be conditionalized on MACH_KDB, but
84 * doing so increases misconfiguration risk.
85 */
86typedef struct cpu_desc_table {
87	struct fake_descriptor	idt[IDTSZ] __attribute__ ((aligned (16)));
88	struct fake_descriptor	gdt[GDTSZ] __attribute__ ((aligned (16)));
89	struct i386_tss		ktss       __attribute__ ((aligned (16)));
90	struct i386_tss		dbtss      __attribute__ ((aligned (16)));
91	struct sysenter_stack	sstk;
92} cpu_desc_table_t;
93
94typedef struct cpu_desc_table64 {
95	struct fake_descriptor64 idt[IDTSZ]      __attribute__ ((aligned (16)));
96	struct fake_descriptor	gdt[GDTSZ]       __attribute__ ((aligned (16)));
97	struct x86_64_tss	ktss             __attribute__ ((aligned (16)));
98	struct sysenter_stack	sstk	         __attribute__ ((aligned (16)));
99	uint8_t			dfstk[PAGE_SIZE] __attribute__ ((aligned (16)));
100} cpu_desc_table64_t;
101
102#define	current_gdt()	(current_cpu_datap()->cpu_desc_index.cdi_gdt)
103#define	current_idt()	(current_cpu_datap()->cpu_desc_index.cdi_idt)
104#define	current_ldt()	(current_cpu_datap()->cpu_desc_index.cdi_ldt)
105#define	current_ktss()	(current_cpu_datap()->cpu_desc_index.cdi_ktss)
106#define	current_dbtss()	(current_cpu_datap()->cpu_desc_index.cdi_dbtss)
107#define	current_sstk()	(current_cpu_datap()->cpu_desc_index.cdi_sstk)
108
109#define	current_ktss64() ((struct x86_64_tss *) current_ktss())
110#define	current_sstk64() ((addr64_t *) current_sstk())
111
112#define	gdt_desc_p(sel) \
113	((struct real_descriptor *)&current_gdt()[sel_idx(sel)])
114#define	ldt_desc_p(sel) \
115	((struct real_descriptor *)&current_ldt()[sel_idx(sel)])
116
117extern void	cpu_desc_init(
118			cpu_data_t	*cdp,
119			boolean_t	is_boot_cpu);
120extern void	cpu_desc_init64(
121			cpu_data_t	*cdp,
122			boolean_t	is_boot_cpu);
123extern void	cpu_desc_load64(
124			cpu_data_t	*cdp);
125extern void	cpu_mode_init(
126			cpu_data_t	*cdp);
127
128static inline boolean_t
129valid_user_data_selector(uint16_t selector)
130{
131    sel_t	sel = selector_to_sel(selector);
132
133    if (selector == 0)
134    	return (TRUE);
135
136    if (sel.ti == SEL_LDT)
137	return (TRUE);
138    else if (sel.index < GDTSZ) {
139	if ((gdt_desc_p(selector)->access & ACC_PL_U) == ACC_PL_U)
140	    return (TRUE);
141    }
142
143    return (FALSE);
144}
145
146static inline boolean_t
147valid_user_code_selector(uint16_t selector)
148{
149    sel_t	sel = selector_to_sel(selector);
150
151    if (selector == 0)
152    	return (FALSE);
153
154    if (sel.ti == SEL_LDT) {
155	if (sel.rpl == USER_PRIV)
156	    return (TRUE);
157    }
158    else if (sel.index < GDTSZ && sel.rpl == USER_PRIV) {
159	if ((gdt_desc_p(selector)->access & ACC_PL_U) == ACC_PL_U)
160	    return (TRUE);
161    }
162
163    return (FALSE);
164}
165
166static inline boolean_t
167valid_user_stack_selector(uint16_t selector)
168{
169    sel_t	sel = selector_to_sel(selector);
170
171    if (selector == 0)
172    	return (FALSE);
173
174    if (sel.ti == SEL_LDT) {
175	if (sel.rpl == USER_PRIV)
176	    return (TRUE);
177    }
178    else if (sel.index < GDTSZ && sel.rpl == USER_PRIV) {
179	if ((gdt_desc_p(selector)->access & ACC_PL_U) == ACC_PL_U)
180	    return (TRUE);
181    }
182
183    return (FALSE);
184}
185
186extern boolean_t
187valid_user_segment_selectors(uint16_t cs,
188                             uint16_t ss,
189                             uint16_t ds,
190                             uint16_t es,
191                             uint16_t fs,
192                             uint16_t gs);
193
194__END_DECLS
195
196#endif	/* _I386_MP_DESC_H_ */
197