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      1 /*	$NetBSD: cpuset.c,v 1.21 2019/05/11 11:53:55 maxv 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 1.21 2019/05/11 11:53:55 maxv 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) >> 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 
     67 struct _cpuset {
     68 	uint32_t	bits[0];
     69 };
     70 
     71 #ifndef _KERNEL
     72 
     73 static size_t cpuset_size = 0;
     74 static size_t cpuset_nentries = 0;
     75 
     76 size_t
     77 /*ARGSUSED*/
     78 _cpuset_size(const cpuset_t *c)
     79 {
     80 
     81 	return cpuset_size;
     82 }
     83 
     84 void
     85 _cpuset_zero(cpuset_t *c)
     86 {
     87 
     88 	memset(c->bits, 0, cpuset_nentries * sizeof(c->bits[0]));
     89 }
     90 
     91 int
     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 ((1U << (unsigned int)(i & CPUSET_MASK)) & c->bits[j]) != 0;
    101 }
    102 
    103 int
    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] |= 1U << (unsigned int)(i & CPUSET_MASK);
    113 	return 0;
    114 }
    115 
    116 int
    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] &= ~(1U << (unsigned int)(i & CPUSET_MASK));
    126 	return 0;
    127 }
    128 
    129 cpuset_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 
    149 void
    150 _cpuset_destroy(cpuset_t *c)
    151 {
    152 
    153 	free(c);
    154 }
    155 
    156 #endif
    157 #endif
    158