1/*-
2 * Copyright (c) 2004 Mark R V Murray
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer
10 *    in this position and unchanged.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 *
26 */
27
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD$");
30
31#if defined(__amd64__) || (defined(__i386__) && !defined(PC98))
32#include "opt_cpu.h"
33#endif
34
35#include <sys/types.h>
36#include <sys/param.h>
37#include <sys/systm.h>
38#include <sys/kernel.h>
39#include <sys/malloc.h>
40#include <sys/random.h>
41#include <sys/selinfo.h>
42#include <sys/sysctl.h>
43
44#if defined(__amd64__) || (defined(__i386__) && !defined(PC98))
45#include <machine/cpufunc.h>
46#include <machine/cputypes.h>
47#include <machine/md_var.h>
48#include <machine/specialreg.h>
49#endif
50
51#include <dev/random/randomdev.h>
52#include <dev/random/randomdev_soft.h>
53
54#if defined(__amd64__) || (defined(__i386__) && !defined(PC98))
55#ifdef PADLOCK_RNG
56extern struct random_systat random_nehemiah;
57#endif
58#ifdef RDRAND_RNG
59extern struct random_systat random_ivy;
60#endif
61#endif
62
63void
64random_ident_hardware(struct random_systat *systat)
65{
66
67	/* Set default to software */
68	*systat = random_yarrow;
69
70	/* Then go looking for hardware */
71#if defined(__amd64__) || (defined(__i386__) && !defined(PC98))
72#ifdef PADLOCK_RNG
73	if (via_feature_rng & VIA_HAS_RNG) {
74		int enable;
75
76		enable = 0;
77		TUNABLE_INT_FETCH("hw.nehemiah_rng_enable", &enable);
78		if (enable)
79			*systat = random_nehemiah;
80	}
81#endif
82#ifdef RDRAND_RNG
83	if (cpu_feature2 & CPUID2_RDRAND) {
84		int enable;
85
86		enable = 0;
87		TUNABLE_INT_FETCH("hw.ivy_rng_enable", &enable);
88		if (enable)
89			*systat = random_ivy;
90	}
91#endif
92#endif
93}
94