[apple/xnu.git] / osfmk / i386 / mp_desc.h

/*
 * Copyright (c) 2000-2005 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * @OSF_COPYRIGHT@
 */
/* 
 * Mach Operating System
 * Copyright (c) 1991,1990 Carnegie Mellon University
 * All Rights Reserved.
 * 
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 * 
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 * 
 * Carnegie Mellon requests users of this software to return to
 * 
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 * 
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */

/*
 */

#ifndef	_I386_MP_DESC_H_
#define	_I386_MP_DESC_H_

#include <mach_kdb.h>
#include <sys/cdefs.h>

__BEGIN_DECLS

/*
 * Multiprocessor i386/i486 systems use a separate copy of the
 * GDT, IDT, LDT, and kernel TSS per processor.  The first three
 * are separate to avoid lock contention: the i386 uses locked
 * memory cycles to access the descriptor tables.  The TSS is
 * separate since each processor needs its own kernel stack,
 * and since using a TSS marks it busy.
 */

#include <i386/seg.h>
#include <i386/tss.h>

/*
 * The descriptor tables are together in a structure
 * allocated one per processor (except for the boot processor).
 * Note that dbtss could be conditionalized on MACH_KDB, but
 * doing so increases misconfiguration risk.
 */
struct mp_desc_table {
	struct fake_descriptor	idt[IDTSZ];	/* IDT */
	struct fake_descriptor	gdt[GDTSZ];	/* GDT */
	struct fake_descriptor	ldt[LDTSZ];	/* LDT */
	struct i386_tss		ktss;
	struct i386_tss		dbtss;
};

#define	current_gdt()	(current_cpu_datap()->cpu_desc_index.cdi_gdt)
#define	current_idt()	(current_cpu_datap()->cpu_desc_index.cdi_idt)
#define	current_ldt()	(current_cpu_datap()->cpu_desc_index.cdi_ldt)
#define	current_ktss()	(current_cpu_datap()->cpu_desc_index.cdi_ktss)
#define	current_dbtss()	(current_cpu_datap()->cpu_desc_index.cdi_dbtss)

#define	gdt_desc_p(sel) \
	((struct real_descriptor *)&current_gdt()[sel_idx(sel)])
#define	ldt_desc_p(sel) \
	((struct real_descriptor *)&current_ldt()[sel_idx(sel)])

extern void	mp_desc_init(cpu_data_t *cdp, boolean_t is_boot_cpu);

static inline boolean_t
valid_user_data_selector(uint16_t selector)
{
    sel_t	sel = selector_to_sel(selector);
    
    if (selector == 0)
    	return (TRUE);

    if (sel.ti == SEL_LDT)
	return (TRUE);
    else if (sel.index < GDTSZ) {
	if ((gdt_desc_p(selector)->access & ACC_PL_U) == ACC_PL_U)
	    return (TRUE);
    }
		
    return (FALSE);
}

static inline boolean_t
valid_user_code_selector(uint16_t selector)
{
    sel_t	sel = selector_to_sel(selector);
    
    if (selector == 0)
    	return (FALSE);

    if (sel.ti == SEL_LDT) {
	if (sel.rpl == USER_PRIV)
	    return (TRUE);
    }
    else if (sel.index < GDTSZ && sel.rpl == USER_PRIV) {
	if ((gdt_desc_p(selector)->access & ACC_PL_U) == ACC_PL_U)
	    return (TRUE);
    }

    return (FALSE);
}

static inline boolean_t
valid_user_stack_selector(uint16_t selector)
{
    sel_t	sel = selector_to_sel(selector);
    
    if (selector == 0)
    	return (FALSE);

    if (sel.ti == SEL_LDT) {
	if (sel.rpl == USER_PRIV)
	    return (TRUE);
    }
    else if (sel.index < GDTSZ && sel.rpl == USER_PRIV) {
	if ((gdt_desc_p(selector)->access & ACC_PL_U) == ACC_PL_U)
	    return (TRUE);
    }
		
    return (FALSE);
}

extern boolean_t
valid_user_segment_selectors(uint16_t cs,
                             uint16_t ss,
                             uint16_t ds,
                             uint16_t es,
                             uint16_t fs,
                             uint16_t gs);

__END_DECLS

#endif	/* _I386_MP_DESC_H_ */
Commit	Line	Data
1c79356b	1	/*
91447636	2	* Copyright (c) 2000-2005 Apple Computer, Inc. All rights reserved.
1c79356b A	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
e5568f75 A	6	* The contents of this file constitute Original Code as defined in and
	7	* are subject to the Apple Public Source License Version 1.1 (the
	8	* "License"). You may not use this file except in compliance with the
	9	* License. Please obtain a copy of the License at
	10	* http://www.apple.com/publicsource and read it before using this file.
1c79356b	11	*
e5568f75 A	12	* This Original Code and all software distributed under the License are
e5568f75 A	13	* distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
1c79356b A	14	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
1c79356b A	15	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
e5568f75 A	16	* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
	17	* License for the specific language governing rights and limitations
	18	* under the License.
1c79356b A	19	*
	20	* @APPLE_LICENSE_HEADER_END@
	21	*/
	22	/*
	23	* @OSF_COPYRIGHT@
	24	*/
	25	/*
	26	* Mach Operating System
	27	* Copyright (c) 1991,1990 Carnegie Mellon University
	28	* All Rights Reserved.
	29	*
	30	* Permission to use, copy, modify and distribute this software and its
	31	* documentation is hereby granted, provided that both the copyright
	32	* notice and this permission notice appear in all copies of the
	33	* software, derivative works or modified versions, and any portions
	34	* thereof, and that both notices appear in supporting documentation.
	35	*
	36	* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
	37	* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
	38	* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
	39	*
	40	* Carnegie Mellon requests users of this software to return to
	41	*
	42	* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
	43	* School of Computer Science
	44	* Carnegie Mellon University
	45	* Pittsburgh PA 15213-3890
	46	*
	47	* any improvements or extensions that they make and grant Carnegie Mellon
	48	* the rights to redistribute these changes.
	49	*/
	50
	51	/*
	52	*/
	53
	54	#ifndef _I386_MP_DESC_H_
	55	#define _I386_MP_DESC_H_
	56
1c79356b	57	#include <mach_kdb.h>
91447636 A	58	#include <sys/cdefs.h>
	59
	60	__BEGIN_DECLS
1c79356b A	61
	62	/*
	63	* Multiprocessor i386/i486 systems use a separate copy of the
	64	* GDT, IDT, LDT, and kernel TSS per processor. The first three
	65	* are separate to avoid lock contention: the i386 uses locked
	66	* memory cycles to access the descriptor tables. The TSS is
	67	* separate since each processor needs its own kernel stack,
	68	* and since using a TSS marks it busy.
	69	*/
	70
	71	#include <i386/seg.h>
	72	#include <i386/tss.h>
	73
	74	/*
	75	* The descriptor tables are together in a structure
	76	* allocated one per processor (except for the boot processor).
	77	* Note that dbtss could be conditionalized on MACH_KDB, but
	78	* doing so increases misconfiguration risk.
	79	*/
	80	struct mp_desc_table {
	81	struct fake_descriptor idt[IDTSZ]; /* IDT */
	82	struct fake_descriptor gdt[GDTSZ]; /* GDT */
	83	struct fake_descriptor ldt[LDTSZ]; /* LDT */
	84	struct i386_tss ktss;
	85	struct i386_tss dbtss;
	86	};
	87
91447636 A	88	#define current_gdt() (current_cpu_datap()->cpu_desc_index.cdi_gdt)
	89	#define current_idt() (current_cpu_datap()->cpu_desc_index.cdi_idt)
	90	#define current_ldt() (current_cpu_datap()->cpu_desc_index.cdi_ldt)
	91	#define current_ktss() (current_cpu_datap()->cpu_desc_index.cdi_ktss)
	92	#define current_dbtss() (current_cpu_datap()->cpu_desc_index.cdi_dbtss)
1c79356b	93
91447636 A	94	#define gdt_desc_p(sel) \
	95	((struct real_descriptor *)&current_gdt()[sel_idx(sel)])
	96	#define ldt_desc_p(sel) \
	97	((struct real_descriptor *)&current_ldt()[sel_idx(sel)])
1c79356b	98
91447636	99	extern void mp_desc_init(cpu_data_t *cdp, boolean_t is_boot_cpu);
1c79356b	100
91447636 A	101	static inline boolean_t
	102	valid_user_data_selector(uint16_t selector)
	103	{
	104	sel_t sel = selector_to_sel(selector);
	105
	106	if (selector == 0)
	107	return (TRUE);
1c79356b	108
91447636 A	109	if (sel.ti == SEL_LDT)
	110	return (TRUE);
	111	else if (sel.index < GDTSZ) {
	112	if ((gdt_desc_p(selector)->access & ACC_PL_U) == ACC_PL_U)
	113	return (TRUE);
	114	}
	115
	116	return (FALSE);
	117	}
	118
	119	static inline boolean_t
	120	valid_user_code_selector(uint16_t selector)
	121	{
	122	sel_t sel = selector_to_sel(selector);
	123
	124	if (selector == 0)
	125	return (FALSE);
	126
	127	if (sel.ti == SEL_LDT) {
	128	if (sel.rpl == USER_PRIV)
	129	return (TRUE);
	130	}
	131	else if (sel.index < GDTSZ && sel.rpl == USER_PRIV) {
	132	if ((gdt_desc_p(selector)->access & ACC_PL_U) == ACC_PL_U)
	133	return (TRUE);
	134	}
	135
	136	return (FALSE);
	137	}
	138
	139	static inline boolean_t
	140	valid_user_stack_selector(uint16_t selector)
	141	{
	142	sel_t sel = selector_to_sel(selector);
	143
	144	if (selector == 0)
	145	return (FALSE);
	146
	147	if (sel.ti == SEL_LDT) {
	148	if (sel.rpl == USER_PRIV)
	149	return (TRUE);
	150	}
	151	else if (sel.index < GDTSZ && sel.rpl == USER_PRIV) {
	152	if ((gdt_desc_p(selector)->access & ACC_PL_U) == ACC_PL_U)
	153	return (TRUE);
	154	}
	155
	156	return (FALSE);
	157	}
	158
	159	extern boolean_t
	160	valid_user_segment_selectors(uint16_t cs,
	161	uint16_t ss,
	162	uint16_t ds,
	163	uint16_t es,
	164	uint16_t fs,
	165	uint16_t gs);
1c79356b	166
91447636	167	__END_DECLS
1c79356b A	168
1c79356b A	169	#endif /* _I386_MP_DESC_H_ */