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cpuset.c revision 1.17.2.1
      1 /*	$NetBSD: cpuset.c,v 1.17.2.1 2012/04/17 00:01:40 yamt 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 1.17.2.1 2012/04/17 00:01:40 yamt 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
    154