]> git.saurik.com Git - apple/xnu.git/blame - osfmk/i386/cpu_number.h
xnu-123.5.tar.gz
[apple/xnu.git] / osfmk / i386 / cpu_number.h
CommitLineData
1c79356b
A
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/*
55 * Machine-dependent definitions for cpu identification.
56 *
57 */
58#ifndef _I386_CPU_NUMBER_H_
59#define _I386_CPU_NUMBER_H_
60
61extern int cpu_number(void);
62
63#ifdef MACH_KERNEL_PRIVATE
64
65#include <platforms.h>
66#include <cpus.h>
67
68#include <mp_v1_1.h>
69
70#if MP_V1_1
71#include <i386/apic.h>
72#include <i386/asm.h>
73
74extern int lapic_id;
75
76extern __inline__ int cpu_number(void)
77{
78 register int cpu;
79
80 __asm__ volatile ("movl " CC_SYM_PREFIX "lapic_id, %0\n"
81 " movl 0(%0), %0\n"
82 " shrl %1, %0\n"
83 " andl %2, %0"
84 : "=r" (cpu)
85 : "i" (LAPIC_ID_SHIFT), "i" (LAPIC_ID_MASK));
86
87 return(cpu);
88}
89#else /* MP_V1_1 */
90/*
91 * At least one corollary cpu type does not have local memory at all.
92 * The only way I found to store the cpu number was in some 386/486
93 * system register. cr3 has bits 0, 1, 2 and 5, 6, 7, 8, 9, 10, 11
94 * available. Right now we use 0, 1 and 2. So we are limited to 8 cpus.
95 * For more cpus, we could use bits 5 - 11 with a shift.
96 *
97 * Even for other machines, like COMPAQ this is much faster the inb/outb
98 * 4 cycles instead of 10 to 30.
99 */
100#if defined(__GNUC__)
101#if NCPUS > 8
102#error cpu_number() definition only works for #cpus <= 8
103#else
104
105extern __inline__ int cpu_number(void)
106{
107 register int cpu;
108
109 __asm__ volatile ("movl %%cr3, %0\n"
110 " andl $0x7, %0"
111 : "=r" (cpu));
112 return(cpu);
113}
114#endif
115#endif /* defined(__GNUC__) */
116
117#endif /* MP_V1_1 */
118
119#endif /* MACH_KERNEL_PRIVATE */
120
121#endif /* _I386_CPU_NUMBER_H_ */