xref: /illumos-gate/usr/src/lib/libc/port/gen/getisax.c (revision 3ba944265c4ae1fcf23ef758537c2e4f4feec16e)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 /*
27  * Copyright (c) 2012, Joyent, Inc.  All rights reserved.
28  */
29 
30 #pragma weak _getisax = getisax
31 
32 #include "lint.h"
33 #include <sys/types.h>
34 #include <sys/auxv.h>
35 
36 extern long ___getauxval(int type);
37 
38 /*
39  * Return the 'hwcap' vector of bits in the AT_SUN_HWCAP and AT_SUN_HWCAP2 aux
40  * vector entries. Therefore there are two words of bits here.
41  *
42  * As a convenience, the routine returns the maximum number of array alements
43  * that may contain non-zero values.
44  */
45 uint_t
46 getisax(uint32_t *array, uint_t n)
47 {
48 	int i;
49 	static uint32_t auxv_hwcap;
50 	static uint32_t auxv_hwcap_2;
51 
52 	if (auxv_hwcap == 0) {
53 		auxv_hwcap = (uint32_t)___getauxval(AT_SUN_HWCAP);
54 		auxv_hwcap_2 = (uint32_t)___getauxval(AT_SUN_HWCAP2);
55 	}
56 
57 	if (n > 0) {
58 		if (n >= 1)
59 			array[0] = auxv_hwcap;
60 		if (n >= 2)
61 			array[1] = auxv_hwcap_2;
62 		for (i = 2; i < n; i++)
63 			array[i] = 0;
64 	}
65 
66 	return (auxv_hwcap == 0 ? 0 : n >= 2 ? 2 : 1);
67 }
68