src/sys/kern/subr_evcount.c

159 lines
4.0 KiB
C

/* $OpenBSD: subr_evcount.c,v 1.16 2023/09/16 09:33:27 mpi Exp $ */
/*
* Copyright (c) 2004 Artur Grabowski <art@openbsd.org>
* Copyright (c) 2004 Aaron Campbell <aaron@openbsd.org>
* All rights reserved.
*
* 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. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``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 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/param.h>
#include <sys/evcount.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/percpu.h>
static TAILQ_HEAD(,evcount) evcount_list = TAILQ_HEAD_INITIALIZER(evcount_list);
static TAILQ_HEAD(,evcount) evcount_percpu_init_list =
TAILQ_HEAD_INITIALIZER(evcount_percpu_init_list);
static int evcount_percpu_done;
void
evcount_attach(struct evcount *ec, const char *name, void *data)
{
static int nextid = 0;
memset(ec, 0, sizeof(*ec));
ec->ec_name = name;
ec->ec_id = ++nextid;
ec->ec_data = data;
TAILQ_INSERT_TAIL(&evcount_list, ec, next);
}
void
evcount_percpu(struct evcount *ec)
{
if (evcount_percpu_done == 0) {
TAILQ_REMOVE(&evcount_list, ec, next);
TAILQ_INSERT_TAIL(&evcount_percpu_init_list, ec, next);
} else {
ec->ec_percpu = counters_alloc(1);
}
}
void
evcount_init_percpu(void)
{
struct evcount *ec;
KASSERT(evcount_percpu_done == 0);
TAILQ_FOREACH(ec, &evcount_percpu_init_list, next) {
ec->ec_percpu = counters_alloc(1);
counters_add(ec->ec_percpu, 0, ec->ec_count);
ec->ec_count = 0;
}
TAILQ_CONCAT(&evcount_list, &evcount_percpu_init_list, next);
evcount_percpu_done = 1;
}
void
evcount_detach(struct evcount *ec)
{
TAILQ_REMOVE(&evcount_list, ec, next);
if (ec->ec_percpu != NULL) {
counters_free(ec->ec_percpu, 1);
ec->ec_percpu = NULL;
}
}
void
evcount_inc(struct evcount *ec)
{
if (ec->ec_percpu != NULL)
counters_inc(ec->ec_percpu, 0);
else
ec->ec_count++;
}
#ifndef SMALL_KERNEL
int
evcount_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
void *newp, size_t newlen)
{
int error = 0, s, nintr, i;
struct evcount *ec;
uint64_t count, scratch;
if (newp != NULL)
return (EPERM);
if (name[0] != KERN_INTRCNT_NUM) {
if (namelen != 2)
return (ENOTDIR);
if (name[1] < 0)
return (EINVAL);
i = name[1];
} else
i = -1;
nintr = 0;
TAILQ_FOREACH(ec, &evcount_list, next) {
if (nintr++ == i)
break;
}
switch (name[0]) {
case KERN_INTRCNT_NUM:
error = sysctl_rdint(oldp, oldlenp, NULL, nintr);
break;
case KERN_INTRCNT_CNT:
if (ec == NULL)
return (ENOENT);
if (ec->ec_percpu != NULL) {
counters_read(ec->ec_percpu, &count, 1, &scratch);
} else {
s = splhigh();
count = ec->ec_count;
splx(s);
}
error = sysctl_rdquad(oldp, oldlenp, NULL, count);
break;
case KERN_INTRCNT_NAME:
if (ec == NULL)
return (ENOENT);
error = sysctl_rdstring(oldp, oldlenp, NULL, ec->ec_name);
break;
case KERN_INTRCNT_VECTOR:
if (ec == NULL || ec->ec_data == NULL)
return (ENOENT);
error = sysctl_rdint(oldp, oldlenp, NULL,
*((int *)ec->ec_data));
break;
default:
error = EOPNOTSUPP;
break;
}
return (error);
}
#endif /* SMALL_KERNEL */