1/* $OpenBSD: usertc.c,v 1.5 2022/09/22 04:57:07 robert Exp $ */ 2/* 3 * Copyright (c) 2020 Paul Irofti <paul@irofti.net> 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18#include <sys/types.h> 19#include <sys/timetc.h> 20 21static inline u_int 22rdtsc_lfence(void) 23{ 24 uint32_t hi, lo; 25 __asm volatile("lfence; rdtsc" : "=a"(lo), "=d"(hi)); 26 return ((uint64_t)lo)|(((uint64_t)hi)<<32); 27} 28 29static inline u_int 30rdtscp(void) 31{ 32 uint32_t hi, lo; 33 __asm volatile("rdtscp" : "=a"(lo), "=d"(hi) : : "ecx"); 34 return ((uint64_t)lo)|(((uint64_t)hi)<<32); 35} 36 37static int 38tc_get_timecount(struct timekeep *tk, u_int *tc) 39{ 40 switch (tk->tk_user) { 41 case TC_TSC_LFENCE: 42 *tc = rdtsc_lfence(); 43 return 0; 44 case TC_TSC_RDTSCP: 45 *tc = rdtscp(); 46 return 0; 47 } 48 49 return -1; 50} 51 52int (*const _tc_get_timecount)(struct timekeep *, u_int *) = tc_get_timecount; 53