1 /*-
2 * Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org>
3 * Copyright (c) 2016, 2017, 2019, 2021 The FreeBSD Foundation
4 * Copyright (c) 2021 Dmitry Chagin <dchagin@FreeBSD.org>
5 *
6 * Portions of this software were developed by Konstantin Belousov
7 * under sponsorship from the FreeBSD Foundation.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31 #include <sys/param.h>
32 #include <x86/cputypes.h>
33 #include <x86/x86_var.h>
34 #include <x86/specialreg.h>
35
36 #include <machine/cpufunc.h>
37
38 #include <x86/linux/linux_x86.h>
39
40 int
linux_vdso_tsc_selector_idx(void)41 linux_vdso_tsc_selector_idx(void)
42 {
43 bool amd_cpu;
44
45 if (cpu_feature == 0)
46 return (2); /* should not happen due to RDTSC */
47
48 amd_cpu = (cpu_vendor_id == CPU_VENDOR_AMD ||
49 cpu_vendor_id == CPU_VENDOR_HYGON);
50
51 if ((amd_feature & AMDID_RDTSCP) != 0)
52 return (3);
53 if ((cpu_feature & CPUID_SSE2) == 0)
54 return (2);
55 return (amd_cpu ? 1 : 0);
56 }
57
58 int
linux_vdso_cpu_selector_idx(void)59 linux_vdso_cpu_selector_idx(void)
60 {
61
62 if ((cpu_stdext_feature2 & CPUID_STDEXT2_RDPID) != 0)
63 return (LINUX_VDSO_CPU_RDPID);
64
65 return ((amd_feature & AMDID_RDTSCP) == 0 ?
66 LINUX_VDSO_CPU_DEFAULT : LINUX_VDSO_CPU_RDTSCP);
67 }
68