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
63 struct _cpuset {
64 uint32_t bits[0];
65 };
66
67 #ifndef _KERNEL
68
69 static size_t cpuset_size = 0;
70 static size_t cpuset_nentries = 0;
71
72 size_t
73 /*ARGSUSED*/
_cpuset_size(const cpuset_t * c)74 _cpuset_size(const cpuset_t *c)
75 {
76
77 return cpuset_size;
78 }
79
80 void
_cpuset_zero(cpuset_t * c)81 _cpuset_zero(cpuset_t *c)
82 {
83
84 memset(c->bits, 0, cpuset_nentries * sizeof(c->bits[0]));
85 }
86
87 int
_cpuset_isset(cpuid_t i,const cpuset_t * c)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
99 int
_cpuset_set(cpuid_t i,cpuset_t * c)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
112 int
_cpuset_clr(cpuid_t i,cpuset_t * c)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
125 cpuset_t *
_cpuset_create(void)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
145 void
_cpuset_destroy(cpuset_t * c)146 _cpuset_destroy(cpuset_t *c)
147 {
148
149 free(c);
150 }
151
152 #endif
153 #endif
154