1/* 2 * Copyright 2017, Data61 3 * Commonwealth Scientific and Industrial Research Organisation (CSIRO) 4 * ABN 41 687 119 230. 5 * 6 * This software may be distributed and modified according to the terms of 7 * the BSD 2-Clause license. Note that NO WARRANTY is provided. 8 * See "LICENSE_BSD2.txt" for details. 9 * 10 * @TAG(DATA61_BSD) 11 */ 12#pragma once 13 14#include <utils/attribute.h> 15#include <platsupport/plat/hpet.h> 16#include <platsupport/plat/pit.h> 17 18/* just read the tsc. This may be executed out of order as it is unserialised */ 19static inline uint64_t 20rdtsc_pure(void) 21{ 22 uint32_t high, low; 23 24 __asm__ __volatile__ ( 25 "rdtsc" 26 : "=a" (low), 27 "=d" (high) 28 : /* no input */ 29 : /* no clobbers */ 30 ); 31 32 return (((uint64_t) high) << 32llu) + (uint64_t) low; 33 34} 35 36/* serialised read of the tsc. This will execute in order and no memory loads will be executed 37 * beforehand */ 38static inline uint64_t 39rdtsc_cpuid(void) 40{ 41 42 uint32_t high, low; 43 44 __asm__ __volatile__ ( 45 "movl $0, %%eax \n" 46 "movl $0, %%ecx \n" 47 "cpuid \n" 48 "rdtsc \n" 49 "movl %%edx, %0 \n" 50 "movl %%eax, %1 \n" 51 "movl $0, %%eax \n" 52 "movl $0, %%ecx \n" 53 "cpuid \n" 54 : "=r" (high), "=r" (low) 55 : /* no inputs */ 56 : "eax", "ebx", "ecx", "edx" 57 ); 58 59 return ((uint64_t) high) << 32llu | (uint64_t) low; 60} 61 62#define TSC_TICKS_TO_NS(cycles_per_us) ((rdtsc_pure() / (uint64_t) cycles_per_us) * NS_IN_US) 63 64/** 65 * Calculates number of ticks per second of the time stamp counter 66 * This function takes complete control of the given timer for 67 * the duraction of the calculation and will reprogram it. It 68 * may also leave un-acked interrupts 69 * 70 * @return Ticks per second, or 0 on error 71 */ 72uint64_t tsc_calculate_frequency_hpet(const hpet_t *hpet); 73uint64_t tsc_calculate_frequency_pit(pit_t *pit); 74 75static inline uint64_t tsc_get_time(uint64_t freq) 76{ 77 return muldivu64(rdtsc_pure(), NS_IN_S, freq); 78} 79