common/lib/libc/sys/cpuset.c

   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*/
  74 _cpuset_size(const cpuset_t *c)
  75 {
  76
  77         return cpuset_size;
  78 }
  79
  80 void
  81 _cpuset_zero(cpuset_t *c)
  82 {
  83
  84         memset(c->bits, 0, cpuset_nentries * sizeof(c->bits[0]));
  85 }
  86
  87 int
  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
 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
 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 *
 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
 146 _cpuset_destroy(cpuset_t *c)
 147 {
 148
 149         free(c);
 150 }
 151
 152 #endif
 153 #endif