cpuset.c revision 1.18 
1/*	$NetBSD: cpuset.c,v 1.18 2012/03/09 15:41:16 christos Exp $	*/
2
3/*-
4 * Copyright (c) 2008 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Christos Zoulas.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#ifndef _STANDALONE
33#include <sys/cdefs.h>
34#if defined(LIBC_SCCS) && !defined(lint)
35__RCSID("$NetBSD: cpuset.c,v 1.18 2012/03/09 15:41:16 christos Exp $");
36#endif /* LIBC_SCCS and not lint */
37
38#include <sys/param.h>
39#include <sys/sched.h>
40#ifdef _KERNEL
41#include <sys/kmem.h>
42#include <lib/libkern/libkern.h>
43#include <sys/atomic.h>
44#else
45#include <errno.h>
46#include <string.h>
47#include <stdlib.h>
48#include <sys/sysctl.h>
49#endif
50
51#define	CPUSET_SHIFT	5
52#define	CPUSET_MASK	31
53#define CPUSET_NENTRIES(nc)	((nc) > 32 ? ((nc) >> CPUSET_SHIFT) : 1)
54#ifndef __lint__
55#define CPUSET_SIZE(n)	(sizeof( \
56	struct {  \
57		uint32_t bits[0]; \
58	}) + sizeof(uint32_t) * (n))
59#else
60#define CPUSET_SIZE(n)	0
61#endif
62
63struct _cpuset {
64	uint32_t	bits[0];
65};
66
67#ifndef _KERNEL
68
69static size_t cpuset_size = 0;
70static size_t cpuset_nentries = 0;
71
72size_t
73/*ARGSUSED*/
74_cpuset_size(const cpuset_t *c)
75{
76
77	return cpuset_size;
78}
79
80void
81_cpuset_zero(cpuset_t *c)
82{
83
84	memset(c->bits, 0, cpuset_nentries * sizeof(c->bits[0]));
85}
86
87int
88_cpuset_isset(cpuid_t i, const cpuset_t *c)
89{
90	const unsigned long j = i >> CPUSET_SHIFT;
91
92	if (j >= cpuset_nentries) {
93		errno = EINVAL;
94		return -1;
95	}
96	return ((1 << (unsigned int)(i & CPUSET_MASK)) & c->bits[j]) != 0;
97}
98
99int
100_cpuset_set(cpuid_t i, cpuset_t *c)
101{
102	const unsigned long j = i >> CPUSET_SHIFT;
103
104	if (j >= cpuset_nentries) {
105		errno = EINVAL;
106		return -1;
107	}
108	c->bits[j] |= 1 << (unsigned int)(i & CPUSET_MASK);
109	return 0;
110}
111
112int
113_cpuset_clr(cpuid_t i, cpuset_t *c)
114{
115	const unsigned long j = i >> CPUSET_SHIFT;
116
117	if (j >= cpuset_nentries) {
118		errno = EINVAL;
119		return -1;
120	}
121	c->bits[j] &= ~(1 << (unsigned int)(i & CPUSET_MASK));
122	return 0;
123}
124
125cpuset_t *
126_cpuset_create(void)
127{
128
129	if (cpuset_size == 0) {
130		static int mib[2] = { CTL_HW, HW_NCPU };
131		size_t len;
132		u_int nc;
133
134		len = sizeof(nc);
135		if (sysctl(mib, (unsigned int)__arraycount(mib), &nc, &len,
136		    NULL, 0) == -1)
137			return NULL;
138
139		cpuset_nentries = CPUSET_NENTRIES(nc);
140		cpuset_size = CPUSET_SIZE(cpuset_nentries);
141	}
142	return calloc(1, cpuset_size);
143}
144
145void
146_cpuset_destroy(cpuset_t *c)
147{
148
149	free(c);
150}
151
152#endif
153#endif
154