timing.h

00001 /**
00002  * \file timing.h
00003  *
00004  * \brief Portable interface to the CPU cycle counter
00005  *
00006  *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
00007  *  SPDX-License-Identifier: Apache-2.0
00008  *
00009  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
00010  *  not use this file except in compliance with the License.
00011  *  You may obtain a copy of the License at
00012  *
00013  *  http://www.apache.org/licenses/LICENSE-2.0
00014  *
00015  *  Unless required by applicable law or agreed to in writing, software
00016  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
00017  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00018  *  See the License for the specific language governing permissions and
00019  *  limitations under the License.
00020  *
00021  *  This file is part of mbed TLS (https://tls.mbed.org)
00022  */
00023 #ifndef MBEDTLS_TIMING_H
00024 #define MBEDTLS_TIMING_H
00025 
00026 #if !defined(MBEDTLS_CONFIG_FILE)
00027 #include "config.h"
00028 #else
00029 #include MBEDTLS_CONFIG_FILE
00030 #endif
00031 
00032 #if !defined(MBEDTLS_TIMING_ALT)
00033 // Regular implementation
00034 //
00035 
00036 #include <stdint.h>
00037 
00038 #ifdef __cplusplus
00039 extern "C" {
00040 #endif
00041 
00042 /**
00043  * \brief          timer structure
00044  */
00045 struct mbedtls_timing_hr_time
00046 {
00047     unsigned char opaque[32];
00048 };
00049 
00050 /**
00051  * \brief          Context for mbedtls_timing_set/get_delay()
00052  */
00053 typedef struct
00054 {
00055     struct mbedtls_timing_hr_time   timer;
00056     uint32_t                        int_ms;
00057     uint32_t                        fin_ms;
00058 } mbedtls_timing_delay_context;
00059 
00060 extern volatile int mbedtls_timing_alarmed;
00061 
00062 /**
00063  * \brief          Return the CPU cycle counter value
00064  *
00065  * \warning        This is only a best effort! Do not rely on this!
00066  *                 In particular, it is known to be unreliable on virtual
00067  *                 machines.
00068  */
00069 unsigned long mbedtls_timing_hardclock( void );
00070 
00071 /**
00072  * \brief          Return the elapsed time in milliseconds
00073  *
00074  * \param val      points to a timer structure
00075  * \param reset    if set to 1, the timer is restarted
00076  */
00077 unsigned long mbedtls_timing_get_timer( struct mbedtls_timing_hr_time *val, int reset );
00078 
00079 /**
00080  * \brief          Setup an alarm clock
00081  *
00082  * \param seconds  delay before the "mbedtls_timing_alarmed" flag is set
00083  *
00084  * \warning        Only one alarm at a time  is supported. In a threaded
00085  *                 context, this means one for the whole process, not one per
00086  *                 thread.
00087  */
00088 void mbedtls_set_alarm( int seconds );
00089 
00090 /**
00091  * \brief          Set a pair of delays to watch
00092  *                 (See \c mbedtls_timing_get_delay().)
00093  *
00094  * \param data     Pointer to timing data
00095  *                 Must point to a valid \c mbedtls_timing_delay_context struct.
00096  * \param int_ms   First (intermediate) delay in milliseconds.
00097  * \param fin_ms   Second (final) delay in milliseconds.
00098  *                 Pass 0 to cancel the current delay.
00099  */
00100 void mbedtls_timing_set_delay( void *data, uint32_t int_ms, uint32_t fin_ms );
00101 
00102 /**
00103  * \brief          Get the status of delays
00104  *                 (Memory helper: number of delays passed.)
00105  *
00106  * \param data     Pointer to timing data
00107  *                 Must point to a valid \c mbedtls_timing_delay_context struct.
00108  *
00109  * \return         -1 if cancelled (fin_ms = 0)
00110  *                  0 if none of the delays are passed,
00111  *                  1 if only the intermediate delay is passed,
00112  *                  2 if the final delay is passed.
00113  */
00114 int mbedtls_timing_get_delay( void *data );
00115 
00116 #ifdef __cplusplus
00117 }
00118 #endif
00119 
00120 #else  /* MBEDTLS_TIMING_ALT */
00121 #include "timing_alt.h"
00122 #endif /* MBEDTLS_TIMING_ALT */
00123 
00124 #ifdef __cplusplus
00125 extern "C" {
00126 #endif
00127 
00128 #if defined(MBEDTLS_SELF_TEST)
00129 /**
00130  * \brief          Checkup routine
00131  *
00132  * \return         0 if successful, or 1 if a test failed
00133  */
00134 int mbedtls_timing_self_test( int verbose );
00135 #endif
00136 
00137 #ifdef __cplusplus
00138 }
00139 #endif
00140 
00141 #endif /* timing.h */