/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2021 The FreeBSD Foundation
 * Copyright (c) 2022 Dmitry Chagin <dchagin@FreeBSD.org>
 *
 * Portions of this software were developed by Konstantin Belousov
 * under sponsorship from the FreeBSD Foundation.
 *
 * 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 <x86/linux/linux_x86.h>

static int
__vdso_getcpu_rdpid(void)
{
	register_t res;

	__asm("rdpid	%0" : "=r" (res));
	return ((int)res);
}

static int
__vdso_getcpu_rdtscp(void)
{
	int res;

	__asm("rdtscp" : "=c" (res) : : "eax", "edx");
	return (res);
}

static int
__vdso_getcpu_try(void)
{
	int res;

	switch (kern_cpu_selector) {
	case LINUX_VDSO_CPU_RDTSCP:
		res = __vdso_getcpu_rdtscp();
		break;
	case LINUX_VDSO_CPU_RDPID:
		res = __vdso_getcpu_rdpid();
		break;
	default:
		res = -1;
	}
	return (res);
}