cpuset.c revision 1.19 
1/*	$NetBSD: cpuset.c,v 1.19 2018/01/04 20:57:28 kamil 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 1.19 2018/01/04 20:57:28 kamil Exp $");
36#endif /* LIBC_SCCS and not lint */
37
38#ifdef _LIBC
39#include "namespace.h"
40#endif
41
42#include <sys/param.h>
43#include <sys/sched.h>
44#ifdef _KERNEL
45#include <sys/kmem.h>
46#include <lib/libkern/libkern.h>
47#include <sys/atomic.h>
48#else
49#include <errno.h>
50#include <string.h>
51#include <stdlib.h>
52#include <sys/sysctl.h>
53#endif
54
55#define	CPUSET_SHIFT	5
56#define	CPUSET_MASK	31
57#define CPUSET_NENTRIES(nc)	((nc) > 32 ? ((nc) >> CPUSET_SHIFT) : 1)
58#ifndef __lint__
59#define CPUSET_SIZE(n)	(sizeof( \
60	struct {  \
61		uint32_t bits[0]; \
62	}) + sizeof(uint32_t) * (n))
63#else
64#define CPUSET_SIZE(n)	0
65#endif
66
67struct _cpuset {
68	uint32_t	bits[0];
69};
70
71#ifndef _KERNEL
72
73static size_t cpuset_size = 0;
74static size_t cpuset_nentries = 0;
75
76size_t
77/*ARGSUSED*/
78_cpuset_size(const cpuset_t *c)
79{
80
81	return cpuset_size;
82}
83
84void
85_cpuset_zero(cpuset_t *c)
86{
87
88	memset(c->bits, 0, cpuset_nentries * sizeof(c->bits[0]));
89}
90
91int
92_cpuset_isset(cpuid_t i, const cpuset_t *c)
93{
94	const unsigned long j = i >> CPUSET_SHIFT;
95
96	if (j >= cpuset_nentries) {
97		errno = EINVAL;
98		return -1;
99	}
100	return ((1 << (unsigned int)(i & CPUSET_MASK)) & c->bits[j]) != 0;
101}
102
103int
104_cpuset_set(cpuid_t i, cpuset_t *c)
105{
106	const unsigned long j = i >> CPUSET_SHIFT;
107
108	if (j >= cpuset_nentries) {
109		errno = EINVAL;
110		return -1;
111	}
112	c->bits[j] |= 1 << (unsigned int)(i & CPUSET_MASK);
113	return 0;
114}
115
116int
117_cpuset_clr(cpuid_t i, cpuset_t *c)
118{
119	const unsigned long j = i >> CPUSET_SHIFT;
120
121	if (j >= cpuset_nentries) {
122		errno = EINVAL;
123		return -1;
124	}
125	c->bits[j] &= ~(1 << (unsigned int)(i & CPUSET_MASK));
126	return 0;
127}
128
129cpuset_t *
130_cpuset_create(void)
131{
132
133	if (cpuset_size == 0) {
134		static int mib[2] = { CTL_HW, HW_NCPU };
135		size_t len;
136		u_int nc;
137
138		len = sizeof(nc);
139		if (sysctl(mib, (unsigned int)__arraycount(mib), &nc, &len,
140		    NULL, 0) == -1)
141			return NULL;
142
143		cpuset_nentries = CPUSET_NENTRIES(nc);
144		cpuset_size = CPUSET_SIZE(cpuset_nentries);
145	}
146	return calloc(1, cpuset_size);
147}
148
149void
150_cpuset_destroy(cpuset_t *c)
151{
152
153	free(c);
154}
155
156#endif
157#endif
158