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 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 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