osfmk/i386/mp_desc.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  * @OSF_COPYRIGHT@
  27  */
  28 /*
  29  * Mach Operating System
  30  * Copyright (c) 1991,1990 Carnegie Mellon University
  31  * All Rights Reserved.
  32  *
  33  * Permission to use, copy, modify and distribute this software and its
  34  * documentation is hereby granted, provided that both the copyright
  35  * notice and this permission notice appear in all copies of the
  36  * software, derivative works or modified versions, and any portions
  37  * thereof, and that both notices appear in supporting documentation.
  38  *
  39  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  40  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  41  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  42  *
  43  * Carnegie Mellon requests users of this software to return to
  44  *
  45  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  46  *  School of Computer Science
  47  *  Carnegie Mellon University
  48  *  Pittsburgh PA 15213-3890
  49  *
  50  * any improvements or extensions that they make and grant Carnegie Mellon
  51  * the rights to redistribute these changes.
  52  */
  53
  54 /*
  55  */
  56
  57 #ifndef _I386_MP_DESC_H_
  58 #define _I386_MP_DESC_H_
  59
  60 #include <cpus.h>
  61 #include <mach_kdb.h>
  62
  63 /*
  64  * Multiprocessor i386/i486 systems use a separate copy of the
  65  * GDT, IDT, LDT, and kernel TSS per processor.  The first three
  66  * are separate to avoid lock contention: the i386 uses locked
  67  * memory cycles to access the descriptor tables.  The TSS is
  68  * separate since each processor needs its own kernel stack,
  69  * and since using a TSS marks it busy.
  70  */
  71
  72 #include <i386/seg.h>
  73 #include <i386/tss.h>
  74
  75 /*
  76  * The descriptor tables are together in a structure
  77  * allocated one per processor (except for the boot processor).
  78  * Note that dbtss could be conditionalized on MACH_KDB, but
  79  * doing so increases misconfiguration risk.
  80  */
  81 struct mp_desc_table {
  82         struct fake_descriptor  idt[IDTSZ];     /* IDT */
  83         struct fake_descriptor  gdt[GDTSZ];     /* GDT */
  84         struct fake_descriptor  ldt[LDTSZ];     /* LDT */
  85         struct i386_tss         ktss;
  86         struct i386_tss         dbtss;
  87 };
  88
  89 /*
  90  * They are pointed to by a per-processor array.
  91  */
  92 extern struct mp_desc_table     *mp_desc_table[NCPUS];
  93
  94 /*
  95  * The kernel TSS gets its own pointer.
  96  */
  97 extern struct i386_tss          *mp_ktss[NCPUS];
  98 #if     MACH_KDB
  99 extern struct i386_tss          *mp_dbtss[NCPUS];
 100 #endif  /* MACH_KDB */
 101
 102 /*
 103  * So does the GDT and IDT.
 104  */
 105 extern struct fake_descriptor   *mp_gdt[NCPUS];
 106 extern struct fake_descriptor   *mp_idt[NCPUS];
 107
 108
 109 /*
 110  * Each CPU calls this routine to set up its descriptor tables.
 111  */
 112
 113 extern struct mp_desc_table *   mp_desc_init(
 114                                         int             cpu);
 115 extern void                     interrupt_stack_alloc(void);
 116
 117 #endif  /* _I386_MP_DESC_H_ */