xref: /freebsd/sys/x86/linux/linux_vdso_getcpu_x86.inc (revision 5a6a4fb284b1a9c4b4105fd6ab8143356f3ef3f7)
1*5a6a4fb2SDmitry Chagin/*-
2*5a6a4fb2SDmitry Chagin * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3*5a6a4fb2SDmitry Chagin *
4*5a6a4fb2SDmitry Chagin * Copyright (c) 2021 The FreeBSD Foundation
5*5a6a4fb2SDmitry Chagin * Copyright (c) 2022 Dmitry Chagin <dchagin@FreeBSD.org>
6*5a6a4fb2SDmitry Chagin *
7*5a6a4fb2SDmitry Chagin * Portions of this software were developed by Konstantin Belousov
8*5a6a4fb2SDmitry Chagin * under sponsorship from the FreeBSD Foundation.
9*5a6a4fb2SDmitry Chagin *
10*5a6a4fb2SDmitry Chagin * Redistribution and use in source and binary forms, with or without
11*5a6a4fb2SDmitry Chagin * modification, are permitted provided that the following conditions
12*5a6a4fb2SDmitry Chagin * are met:
13*5a6a4fb2SDmitry Chagin * 1. Redistributions of source code must retain the above copyright
14*5a6a4fb2SDmitry Chagin *    notice, this list of conditions and the following disclaimer.
15*5a6a4fb2SDmitry Chagin * 2. Redistributions in binary form must reproduce the above copyright
16*5a6a4fb2SDmitry Chagin *    notice, this list of conditions and the following disclaimer in the
17*5a6a4fb2SDmitry Chagin *    documentation and/or other materials provided with the distribution.
18*5a6a4fb2SDmitry Chagin *
19*5a6a4fb2SDmitry Chagin * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20*5a6a4fb2SDmitry Chagin * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21*5a6a4fb2SDmitry Chagin * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22*5a6a4fb2SDmitry Chagin * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23*5a6a4fb2SDmitry Chagin * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24*5a6a4fb2SDmitry Chagin * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25*5a6a4fb2SDmitry Chagin * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26*5a6a4fb2SDmitry Chagin * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27*5a6a4fb2SDmitry Chagin * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28*5a6a4fb2SDmitry Chagin * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29*5a6a4fb2SDmitry Chagin * SUCH DAMAGE.
30*5a6a4fb2SDmitry Chagin */
31*5a6a4fb2SDmitry Chagin
32*5a6a4fb2SDmitry Chagin#include <x86/linux/linux_x86.h>
33*5a6a4fb2SDmitry Chagin
34*5a6a4fb2SDmitry Chaginstatic int
35*5a6a4fb2SDmitry Chagin__vdso_getcpu_rdpid(void)
36*5a6a4fb2SDmitry Chagin{
37*5a6a4fb2SDmitry Chagin	register_t res;
38*5a6a4fb2SDmitry Chagin
39*5a6a4fb2SDmitry Chagin	__asm("rdpid	%0" : "=r" (res));
40*5a6a4fb2SDmitry Chagin	return ((int)res);
41*5a6a4fb2SDmitry Chagin}
42*5a6a4fb2SDmitry Chagin
43*5a6a4fb2SDmitry Chaginstatic int
44*5a6a4fb2SDmitry Chagin__vdso_getcpu_rdtscp(void)
45*5a6a4fb2SDmitry Chagin{
46*5a6a4fb2SDmitry Chagin	int res;
47*5a6a4fb2SDmitry Chagin
48*5a6a4fb2SDmitry Chagin	__asm("rdtscp" : "=c" (res) : : "eax", "edx");
49*5a6a4fb2SDmitry Chagin	return (res);
50*5a6a4fb2SDmitry Chagin}
51*5a6a4fb2SDmitry Chagin
52*5a6a4fb2SDmitry Chaginstatic int
53*5a6a4fb2SDmitry Chagin__vdso_getcpu_try(void)
54*5a6a4fb2SDmitry Chagin{
55*5a6a4fb2SDmitry Chagin	int res;
56*5a6a4fb2SDmitry Chagin
57*5a6a4fb2SDmitry Chagin	switch (kern_cpu_selector) {
58*5a6a4fb2SDmitry Chagin	case LINUX_VDSO_CPU_RDTSCP:
59*5a6a4fb2SDmitry Chagin		res = __vdso_getcpu_rdtscp();
60*5a6a4fb2SDmitry Chagin		break;
61*5a6a4fb2SDmitry Chagin	case LINUX_VDSO_CPU_RDPID:
62*5a6a4fb2SDmitry Chagin		res = __vdso_getcpu_rdpid();
63*5a6a4fb2SDmitry Chagin		break;
64*5a6a4fb2SDmitry Chagin	default:
65*5a6a4fb2SDmitry Chagin		res = -1;
66*5a6a4fb2SDmitry Chagin	}
67*5a6a4fb2SDmitry Chagin	return (res);
68*5a6a4fb2SDmitry Chagin}
69