/*-
 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
 *
 * Copyright (c) 2012, 2013 Konstantin Belousov <kib@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.
 *
 * $FreeBSD$
 */

#ifndef __MACHINE_COUNTER_H__
#define __MACHINE_COUNTER_H__

#include <sys/pcpu.h>
#ifdef INVARIANTS
#include <sys/proc.h>
#endif

extern struct pcpu __pcpu[];

#define	EARLY_COUNTER	&__pcpu[0].pc_early_dummy_counter

#ifdef __powerpc64__

#define	counter_enter()	do {} while (0)
#define	counter_exit()	do {} while (0)

#ifdef IN_SUBR_COUNTER_C
static inline uint64_t
counter_u64_read_one(uint64_t *p, int cpu)
{

	return (*(uint64_t *)((char *)p + sizeof(struct pcpu) * cpu));
}

static inline uint64_t
counter_u64_fetch_inline(uint64_t *p)
{
	uint64_t r;
	int i;

	r = 0;
	CPU_FOREACH(i)
		r += counter_u64_read_one((uint64_t *)p, i);

	return (r);
}

static void
counter_u64_zero_one_cpu(void *arg)
{

	*((uint64_t *)((char *)arg + sizeof(struct pcpu) *
	    PCPU_GET(cpuid))) = 0;
}

static inline void
counter_u64_zero_inline(counter_u64_t c)
{

	smp_rendezvous(smp_no_rendezvous_barrier, counter_u64_zero_one_cpu,
	    smp_no_rendezvous_barrier, c);
}
#endif

#define	counter_u64_add_protected(c, i)	counter_u64_add(c, i)

static inline void
counter_u64_add(counter_u64_t c, int64_t inc)
{
	uint64_t ccpu, old;

	__asm __volatile("\n"
      "1:\n\t"
	    "mfsprg	%0, 0\n\t"
	    "ldarx	%1, %0, %2\n\t"
	    "add	%1, %1, %3\n\t"
	    "stdcx.	%1, %0, %2\n\t"
	    "bne-	1b"
	    : "=&b" (ccpu), "=&r" (old)
	    : "r" ((char *)c - (char *)&__pcpu[0]), "r" (inc)
	    : "cr0", "memory");
}

#else	/* !64bit */

#define	counter_enter()	critical_enter()
#define	counter_exit()	critical_exit()

#ifdef IN_SUBR_COUNTER_C
/* XXXKIB non-atomic 64bit read */
static inline uint64_t
counter_u64_read_one(uint64_t *p, int cpu)
{

	return (*(uint64_t *)((char *)p + sizeof(struct pcpu) * cpu));
}

static inline uint64_t
counter_u64_fetch_inline(uint64_t *p)
{
	uint64_t r;
	int i;

	r = 0;
	for (i = 0; i < mp_ncpus; i++)
		r += counter_u64_read_one((uint64_t *)p, i);

	return (r);
}

/* XXXKIB non-atomic 64bit store, might interrupt increment */
static void
counter_u64_zero_one_cpu(void *arg)
{

	*((uint64_t *)((char *)arg + sizeof(struct pcpu) *
	    PCPU_GET(cpuid))) = 0;
}

static inline void
counter_u64_zero_inline(counter_u64_t c)
{

	smp_rendezvous(smp_no_rendezvous_barrier, counter_u64_zero_one_cpu,
	    smp_no_rendezvous_barrier, c);
}
#endif

#define	counter_u64_add_protected(c, inc)	do {	\
	CRITICAL_ASSERT(curthread);			\
	*(uint64_t *)zpcpu_get(c) += (inc);		\
} while (0)

static inline void
counter_u64_add(counter_u64_t c, int64_t inc)
{

	counter_enter();
	counter_u64_add_protected(c, inc);
	counter_exit();
}

#endif	/* 64bit */

#endif	/* ! __MACHINE_COUNTER_H__ */