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