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