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/*-
* Copyright (c) 2008 Yahoo!, Inc.
* All rights reserved.
* Written by: John Baldwin <jhb@FreeBSD.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/pcpu.h>
#include <sys/sysctl.h>
#include <kvm.h>
#include <limits.h>
#include <stdlib.h>
#include "kvm_private.h"
static struct nlist kvm_pcpu_nl[] = {
{ "_cpuid_to_pcpu" },
{ "_mp_maxcpus" },
{ NULL },
};
/*
* Kernel per-CPU data state. We cache this stuff on the first
* access.
*/
static void **pcpu_data;
static int maxcpu;
#define NL_CPUID_TO_PCPU 0
#define NL_MP_MAXCPUS 1
static int
_kvm_pcpu_init(kvm_t *kd)
{
size_t len;
int max;
void *data;
if (kvm_nlist(kd, kvm_pcpu_nl) < 0)
return (-1);
if (kvm_pcpu_nl[NL_CPUID_TO_PCPU].n_value == 0) {
_kvm_err(kd, kd->program, "unable to find cpuid_to_pcpu");
return (-1);
}
if (kvm_pcpu_nl[NL_MP_MAXCPUS].n_value == 0) {
_kvm_err(kd, kd->program, "unable to find mp_maxcpus");
return (-1);
}
if (kvm_read(kd, kvm_pcpu_nl[NL_MP_MAXCPUS].n_value, &max,
sizeof(max)) != sizeof(max)) {
_kvm_err(kd, kd->program, "cannot read mp_maxcpus");
return (-1);
}
len = max * sizeof(void *);
data = malloc(len);
if (data == NULL) {
_kvm_err(kd, kd->program, "out of memory");
return (-1);
}
if (kvm_read(kd, kvm_pcpu_nl[NL_CPUID_TO_PCPU].n_value, data, len) !=
len) {
_kvm_err(kd, kd->program, "cannot read cpuid_to_pcpu array");
free(data);
return (-1);
}
pcpu_data = data;
maxcpu = max;
return (0);
}
static void
_kvm_pcpu_clear(void)
{
maxcpu = 0;
free(pcpu_data);
pcpu_data = NULL;
}
void *
kvm_getpcpu(kvm_t *kd, int cpu)
{
char *buf;
int i;
if (kd == NULL) {
_kvm_pcpu_clear();
return (NULL);
}
if (maxcpu == 0)
if (_kvm_pcpu_init(kd) < 0)
return ((void *)-1);
if (cpu >= maxcpu || pcpu_data[cpu] == NULL)
return (NULL);
buf = malloc(sizeof(struct pcpu));
if (buf == NULL) {
_kvm_err(kd, kd->program, "out of memory");
return ((void *)-1);
}
if (kvm_read(kd, (uintptr_t)pcpu_data[cpu], buf, sizeof(struct pcpu)) !=
sizeof(struct pcpu)) {
_kvm_err(kd, kd->program, "unable to read per-CPU data");
free(buf);
return ((void *)-1);
}
return (buf);
}
int
kvm_getmaxcpu(kvm_t *kd)
{
if (kd == NULL) {
_kvm_pcpu_clear();
return (0);
}
if (maxcpu == 0)
if (_kvm_pcpu_init(kd) < 0)
return (-1);
return (maxcpu);
}
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