1 /** 2 * \file timing.h 3 * 4 * \brief Portable interface to the CPU cycle counter 5 * 6 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved 7 * SPDX-License-Identifier: Apache-2.0 8 * 9 * Licensed under the Apache License, Version 2.0 (the "License"); you may 10 * not use this file except in compliance with the License. 11 * You may obtain a copy of the License at 12 * 13 * http://www.apache.org/licenses/LICENSE-2.0 14 * 15 * Unless required by applicable law or agreed to in writing, software 16 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 17 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 18 * See the License for the specific language governing permissions and 19 * limitations under the License. 20 * 21 * This file is part of mbed TLS (https://tls.mbed.org) 22 */ 23 #ifndef MBEDTLS_TIMING_H 24 #define MBEDTLS_TIMING_H 25 26 #if !defined(MBEDTLS_CONFIG_FILE) 27 #include "config.h" 28 #else 29 #include MBEDTLS_CONFIG_FILE 30 #endif 31 32 #if !defined(MBEDTLS_TIMING_ALT) 33 // Regular implementation 34 // 35 36 #include <stdint.h> 37 38 #ifdef __cplusplus 39 extern "C" { 40 #endif 41 42 /** 43 * \brief timer structure 44 */ 45 struct mbedtls_timing_hr_time 46 { 47 unsigned char opaque[32]; 48 }; 49 50 /** 51 * \brief Context for mbedtls_timing_set/get_delay() 52 */ 53 typedef struct 54 { 55 struct mbedtls_timing_hr_time timer; 56 uint32_t int_ms; 57 uint32_t fin_ms; 58 } mbedtls_timing_delay_context; 59 60 extern volatile int mbedtls_timing_alarmed; 61 62 /** 63 * \brief Return the CPU cycle counter value 64 * 65 * \warning This is only a best effort! Do not rely on this! 66 * In particular, it is known to be unreliable on virtual 67 * machines. 68 */ 69 unsigned long mbedtls_timing_hardclock( void ); 70 71 /** 72 * \brief Return the elapsed time in milliseconds 73 * 74 * \param val points to a timer structure 75 * \param reset if set to 1, the timer is restarted 76 */ 77 unsigned long mbedtls_timing_get_timer( struct mbedtls_timing_hr_time *val, int reset ); 78 79 /** 80 * \brief Setup an alarm clock 81 * 82 * \param seconds delay before the "mbedtls_timing_alarmed" flag is set 83 * 84 * \warning Only one alarm at a time is supported. In a threaded 85 * context, this means one for the whole process, not one per 86 * thread. 87 */ 88 void mbedtls_set_alarm( int seconds ); 89 90 /** 91 * \brief Set a pair of delays to watch 92 * (See \c mbedtls_timing_get_delay().) 93 * 94 * \param data Pointer to timing data 95 * Must point to a valid \c mbedtls_timing_delay_context struct. 96 * \param int_ms First (intermediate) delay in milliseconds. 97 * \param fin_ms Second (final) delay in milliseconds. 98 * Pass 0 to cancel the current delay. 99 */ 100 void mbedtls_timing_set_delay( void *data, uint32_t int_ms, uint32_t fin_ms ); 101 102 /** 103 * \brief Get the status of delays 104 * (Memory helper: number of delays passed.) 105 * 106 * \param data Pointer to timing data 107 * Must point to a valid \c mbedtls_timing_delay_context struct. 108 * 109 * \return -1 if cancelled (fin_ms = 0) 110 * 0 if none of the delays are passed, 111 * 1 if only the intermediate delay is passed, 112 * 2 if the final delay is passed. 113 */ 114 int mbedtls_timing_get_delay( void *data ); 115 116 #ifdef __cplusplus 117 } 118 #endif 119 120 #else /* MBEDTLS_TIMING_ALT */ 121 #include "timing_alt.h" 122 #endif /* MBEDTLS_TIMING_ALT */ 123 124 #ifdef __cplusplus 125 extern "C" { 126 #endif 127 128 #if defined(MBEDTLS_SELF_TEST) 129 /** 130 * \brief Checkup routine 131 * 132 * \return 0 if successful, or 1 if a test failed 133 */ 134 int mbedtls_timing_self_test( int verbose ); 135 #endif 136 137 #ifdef __cplusplus 138 } 139 #endif 140 141 #endif /* timing.h */ 142
