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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2012 Gleb Smirnoff <glebius@FreeBSD.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. 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.
*
* 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/systm.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/sched.h>
#include <sys/smp.h>
#include <sys/sysctl.h>
#include <vm/uma.h>
#define IN_SUBR_COUNTER_C
#include <sys/counter.h>
void
counter_u64_zero(counter_u64_t c)
{
counter_u64_zero_inline(c);
}
uint64_t
counter_u64_fetch(counter_u64_t c)
{
return (counter_u64_fetch_inline(c));
}
counter_u64_t
counter_u64_alloc(int flags)
{
return (uma_zalloc_pcpu(pcpu_zone_8, flags | M_ZERO));
}
void
counter_u64_free(counter_u64_t c)
{
uma_zfree_pcpu(pcpu_zone_8, c);
}
int
sysctl_handle_counter_u64(SYSCTL_HANDLER_ARGS)
{
uint64_t out;
int error;
out = counter_u64_fetch(*(counter_u64_t *)arg1);
error = SYSCTL_OUT(req, &out, sizeof(uint64_t));
if (error || !req->newptr)
return (error);
/*
* Any write attempt to a counter zeroes it.
*/
counter_u64_zero(*(counter_u64_t *)arg1);
return (0);
}
int
sysctl_handle_counter_u64_array(SYSCTL_HANDLER_ARGS)
{
uint64_t *out;
int error;
out = malloc(arg2 * sizeof(uint64_t), M_TEMP, M_WAITOK);
for (int i = 0; i < arg2; i++)
out[i] = counter_u64_fetch(((counter_u64_t *)arg1)[i]);
error = SYSCTL_OUT(req, out, arg2 * sizeof(uint64_t));
free(out, M_TEMP);
if (error || !req->newptr)
return (error);
/*
* Any write attempt to a counter zeroes it.
*/
for (int i = 0; i < arg2; i++)
counter_u64_zero(((counter_u64_t *)arg1)[i]);
return (0);
}
/*
* MP-friendly version of ppsratecheck().
*
* Returns non-negative if we are in the rate, negative otherwise.
* 0 - rate limit not reached.
* -1 - rate limit reached.
* >0 - rate limit was reached before, and was just reset. The return value
* is number of events since last reset.
*/
int64_t
counter_ratecheck(struct counter_rate *cr, int64_t limit)
{
int64_t val;
int now;
val = cr->cr_over;
now = ticks;
if ((u_int)(now - cr->cr_ticks) >= hz) {
/*
* Time to clear the structure, we are in the next second.
* First try unlocked read, and then proceed with atomic.
*/
if ((cr->cr_lock == 0) &&
atomic_cmpset_acq_int(&cr->cr_lock, 0, 1)) {
/*
* Check if other thread has just went through the
* reset sequence before us.
*/
if ((u_int)(now - cr->cr_ticks) >= hz) {
val = counter_u64_fetch(cr->cr_rate);
counter_u64_zero(cr->cr_rate);
cr->cr_over = 0;
cr->cr_ticks = now;
if (val <= limit)
val = 0;
}
atomic_store_rel_int(&cr->cr_lock, 0);
} else
/*
* We failed to lock, in this case other thread may
* be running counter_u64_zero(), so it is not safe
* to do an update, we skip it.
*/
return (val);
}
counter_u64_add(cr->cr_rate, 1);
if (cr->cr_over != 0)
return (-1);
if (counter_u64_fetch(cr->cr_rate) > limit)
val = cr->cr_over = -1;
return (val);
}
void
counter_u64_sysinit(void *arg)
{
counter_u64_t *cp;
cp = arg;
*cp = counter_u64_alloc(M_WAITOK);
}
void
counter_u64_sysuninit(void *arg)
{
counter_u64_t *cp;
cp = arg;
counter_u64_free(*cp);
}
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