osfmk/i386/mp_desc.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   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.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  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.
  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
  57 #include <cpus.h>
  58 #include <mach_kdb.h>
  59
  60 /*
  61  * Multiprocessor i386/i486 systems use a separate copy of the
  62  * GDT, IDT, LDT, and kernel TSS per processor.  The first three
  63  * are separate to avoid lock contention: the i386 uses locked
  64  * memory cycles to access the descriptor tables.  The TSS is
  65  * separate since each processor needs its own kernel stack,
  66  * and since using a TSS marks it busy.
  67  */
  68
  69 #include <i386/seg.h>
  70 #include <i386/tss.h>
  71
  72 /*
  73  * The descriptor tables are together in a structure
  74  * allocated one per processor (except for the boot processor).
  75  * Note that dbtss could be conditionalized on MACH_KDB, but
  76  * doing so increases misconfiguration risk.
  77  */
  78 struct mp_desc_table {
  79         struct fake_descriptor  idt[IDTSZ];     /* IDT */
  80         struct fake_descriptor  gdt[GDTSZ];     /* GDT */
  81         struct fake_descriptor  ldt[LDTSZ];     /* LDT */
  82         struct i386_tss         ktss;
  83         struct i386_tss         dbtss;
  84 };
  85
  86 /*
  87  * They are pointed to by a per-processor array.
  88  */
  89 extern struct mp_desc_table     *mp_desc_table[NCPUS];
  90
  91 /*
  92  * The kernel TSS gets its own pointer.
  93  */
  94 extern struct i386_tss          *mp_ktss[NCPUS];
  95 #if     MACH_KDB
  96 extern struct i386_tss          *mp_dbtss[NCPUS];
  97 #endif  /* MACH_KDB */
  98
  99 /*
 100  * So does the GDT and IDT.
 101  */
 102 extern struct fake_descriptor   *mp_gdt[NCPUS];
 103 extern struct fake_descriptor   *mp_idt[NCPUS];
 104
 105
 106 /*
 107  * Each CPU calls this routine to set up its descriptor tables.
 108  */
 109
 110 extern struct mp_desc_table *   mp_desc_init(
 111                                         int             cpu);
 112 extern void                     interrupt_stack_alloc(void);
 113
 114 #endif  /* _I386_MP_DESC_H_ */