1 /*
2 * Copyright (c) KATO Takenori, 1997, 1998.
3 *
4 * All rights reserved. Unpublished rights reserved under the copyright
5 * laws of Japan.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer as
13 * the first lines of this file unmodified.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 *
29 * $FreeBSD: releng/5.1/sys/amd64/amd64/initcpu.c 114349 2003-05-01 01:05:25Z peter $
30 */
31
32 #include "opt_cpu.h"
33
34 #include <sys/param.h>
35 #include <sys/kernel.h>
36 #include <sys/systm.h>
37 #include <sys/sysctl.h>
38
39 #include <machine/cputypes.h>
40 #include <machine/md_var.h>
41 #include <machine/specialreg.h>
42
43 void initializecpu(void);
44
45 static int hw_instruction_sse;
46 SYSCTL_INT(_hw, OID_AUTO, instruction_sse, CTLFLAG_RD,
47 &hw_instruction_sse, 0, "SIMD/MMX2 instructions available in CPU");
48
49 int cpu; /* Are we 386, 386sx, 486, etc? */
50 u_int cpu_feature; /* Feature flags */
51 u_int cpu_high; /* Highest arg to CPUID */
52 u_int cpu_id; /* Stepping ID */
53 u_int cpu_procinfo; /* HyperThreading Info / Brand Index / CLFUSH */
54 char cpu_vendor[20]; /* CPU Origin code */
55 u_int cpu_fxsr; /* SSE enabled */
56
57 /*
58 * Initialize CR4 (Control register 4) to enable SSE instructions.
59 */
60 void
61 enable_sse(void)
62 {
63 if ((cpu_feature & CPUID_XMM) && (cpu_feature & CPUID_FXSR)) {
64 load_cr4(rcr4() | CR4_FXSR | CR4_XMM);
65 cpu_fxsr = hw_instruction_sse = 1;
66 }
67 }
68
69 void
70 initializecpu(void)
71 {
72
73 switch (cpu) {
74 default:
75 break;
76 }
77 enable_sse();
78 }
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