/*
 *  Portable interface to the CPU cycle counter
 *
 *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
 *  SPDX-License-Identifier: Apache-2.0
 *
 *  Licensed under the Apache License, Version 2.0 (the "License"); you may
 *  not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *  This file is part of mbed TLS (https://tls.mbed.org)
 */

#include <stdio.h>
#include "timing.h"

#if !defined(unix) && !defined(__unix__) && !defined(__unix) && \
    !defined(__APPLE__) && !defined(_WIN32) && !defined(__QNXNTO__)
#error "This module only works on Unix and Windows, see MBEDTLS_TIMING_C in config.h"
#endif

#ifndef asm
#define asm __asm
#endif

#define MBEDTLS_HAVE_ASM 1

#if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)

#include <windows.h>
#include <winbase.h>

struct _hr_time
{
    LARGE_INTEGER start;
};

#else

#include <unistd.h>
#include <sys/types.h>
#include <sys/time.h>
#include <signal.h>
#include <time.h>

struct _hr_time
{
    struct timeval start;
};

#endif /* _WIN32 && !EFIX64 && !EFI32 */

#if !defined(HAVE_HARDCLOCK) && defined(MBEDTLS_HAVE_ASM) &&  \
    ( defined(_MSC_VER) && defined(_M_IX86) ) || defined(__WATCOMC__)

#define HAVE_HARDCLOCK

uint64_t timing_hardclock( void )
{
    uint64_t tsc;
    __asm   rdtsc
    __asm   mov  [tsc], eax
    return( tsc );
}
#endif /* !HAVE_HARDCLOCK && MBEDTLS_HAVE_ASM &&
          ( _MSC_VER && _M_IX86 ) || __WATCOMC__ */

/* some versions of mingw-64 have 32-bit longs even on x84_64 */
#if !defined(HAVE_HARDCLOCK) && defined(MBEDTLS_HAVE_ASM) &&  \
    defined(__GNUC__) && ( defined(__i386__) || (                       \
    ( defined(__amd64__) || defined( __x86_64__) ) && __SIZEOF_LONG__ == 4 ) )

#define HAVE_HARDCLOCK

uint64_t timing_hardclock( void )
{
    unsigned long lo, hi;
    asm volatile( "rdtsc" : "=a" (lo), "=d" (hi) );
    uint64_t ret = hi;
    ret <<= 32; ret += lo;
    return( ret );
}
#endif /* !HAVE_HARDCLOCK && MBEDTLS_HAVE_ASM &&
          __GNUC__ && __i386__ */

#if !defined(HAVE_HARDCLOCK) && defined(MBEDTLS_HAVE_ASM) &&  \
    defined(__GNUC__) && ( defined(__amd64__) || defined(__x86_64__) )

#define HAVE_HARDCLOCK

uint64_t timing_hardclock( void )
{
    unsigned long lo, hi;
    asm volatile( "rdtsc" : "=a" (lo), "=d" (hi) );
    return( lo | ( hi << 32 ) );
}
#endif /* !HAVE_HARDCLOCK && MBEDTLS_HAVE_ASM &&
          __GNUC__ && ( __amd64__ || __x86_64__ ) */

#if !defined(HAVE_HARDCLOCK) && defined(MBEDTLS_HAVE_ASM) &&  \
    defined(__GNUC__) && ( defined(__powerpc__) || defined(__ppc__) )

#define HAVE_HARDCLOCK

uint64_t timing_hardclock( void )
{
    unsigned long tbl, tbu0, tbu1;

    do
    {
        asm volatile( "mftbu %0" : "=r" (tbu0) );
        asm volatile( "mftb  %0" : "=r" (tbl ) );
        asm volatile( "mftbu %0" : "=r" (tbu1) );
    }
    while( tbu0 != tbu1 );

    return( tbl );
}
#endif /* !HAVE_HARDCLOCK && MBEDTLS_HAVE_ASM &&
          __GNUC__ && ( __powerpc__ || __ppc__ ) */

#if !defined(HAVE_HARDCLOCK) && defined(MBEDTLS_HAVE_ASM) &&  \
    defined(__GNUC__) && defined(__sparc64__)

#if defined(__OpenBSD__)
#warning OpenBSD does not allow access to tick register using software version instead
#else
#define HAVE_HARDCLOCK

uint64_t timing_hardclock( void )
{
    unsigned long tick;
    asm volatile( "rdpr %%tick, %0;" : "=&r" (tick) );
    return( tick );
}
#endif /* __OpenBSD__ */
#endif /* !HAVE_HARDCLOCK && MBEDTLS_HAVE_ASM &&
          __GNUC__ && __sparc64__ */

#if !defined(HAVE_HARDCLOCK) && defined(MBEDTLS_HAVE_ASM) &&  \
    defined(__GNUC__) && defined(__sparc__) && !defined(__sparc64__)

#define HAVE_HARDCLOCK

uint64_t timing_hardclock( void )
{
    unsigned long tick;
    asm volatile( ".byte 0x83, 0x41, 0x00, 0x00" );
    asm volatile( "mov   %%g1, %0" : "=r" (tick) );
    return( tick );
}
#endif /* !HAVE_HARDCLOCK && MBEDTLS_HAVE_ASM &&
          __GNUC__ && __sparc__ && !__sparc64__ */

#if !defined(HAVE_HARDCLOCK) && defined(MBEDTLS_HAVE_ASM) &&      \
    defined(__GNUC__) && defined(__alpha__)

#define HAVE_HARDCLOCK

uint64_t timing_hardclock( void )
{
    uint64_t cc = 0;
    asm volatile( "rpcc %0" : "=r" (cc) );
    return( cc );
}
#endif /* !HAVE_HARDCLOCK && MBEDTLS_HAVE_ASM &&
          __GNUC__ && __alpha__ */

#if !defined(HAVE_HARDCLOCK) && defined(MBEDTLS_HAVE_ASM) &&      \
    defined(__GNUC__) && defined(__ia64__)

#define HAVE_HARDCLOCK

uint64_t timing_hardclock( void )
{
    unsigned long itc;
    asm volatile( "mov %0 = ar.itc" : "=r" (itc) );
    return( itc );
}
#endif /* !HAVE_HARDCLOCK && MBEDTLS_HAVE_ASM &&
          __GNUC__ && __ia64__ */

#if !defined(HAVE_HARDCLOCK) && defined(_MSC_VER) && \
    !defined(EFIX64) && !defined(EFI32)

#define HAVE_HARDCLOCK

uint64_t timing_hardclock( void )
{
    LARGE_INTEGER offset;

    QueryPerformanceCounter( &offset );

    return( (uint64_t)( offset.QuadPart ) );
}
#endif /* !HAVE_HARDCLOCK && _MSC_VER && !EFIX64 && !EFI32 */

#if !defined(HAVE_HARDCLOCK)

#define HAVE_HARDCLOCK

static int hardclock_init = 0;
static struct timeval tv_init;

uint64_t timing_hardclock( void )
{
    struct timeval tv_cur;

    if( hardclock_init == 0 )
    {
        gettimeofday( &tv_init, NULL );
        hardclock_init = 1;
    }

    gettimeofday( &tv_cur, NULL );
    return( ( tv_cur.tv_sec  - tv_init.tv_sec  ) * 1000000
          + ( tv_cur.tv_usec - tv_init.tv_usec ) );
}
#endif /* !HAVE_HARDCLOCK */

volatile int timing_alarmed = 0;

#if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)

unsigned long timing_get_timer( struct timing_hr_time *val, int reset )
{
    struct _hr_time *t = (struct _hr_time *) val;

    if( reset )
    {
        QueryPerformanceCounter( &t->start );
        return( 0 );
    }
    else
    {
        unsigned long delta;
        LARGE_INTEGER now, hfreq;
        QueryPerformanceCounter(  &now );
        QueryPerformanceFrequency( &hfreq );
        delta = (unsigned long)( ( now.QuadPart - t->start.QuadPart ) * 1000ul
                                 / hfreq.QuadPart );
        return( delta );
    }
}

/* It's OK to use a global because alarm() is supposed to be global anyway */
static DWORD alarmMs;

static DWORD WINAPI TimerProc( LPVOID TimerContext )
{
    ((void) TimerContext);
    Sleep( alarmMs );
    timing_alarmed = 1;
    return( TRUE );
}

void set_alarm( int seconds )
{
    DWORD ThreadId;

    if( seconds == 0 )
    {
        /* No need to create a thread for this simple case.
         * Also, this shorcut is more reliable at least on MinGW32 */
        timing_alarmed = 1;
        return;
    }

    timing_alarmed = 0;
    alarmMs = seconds * 1000;
    CloseHandle( CreateThread( NULL, 0, TimerProc, NULL, 0, &ThreadId ) );
}

#else /* _WIN32 && !EFIX64 && !EFI32 */

unsigned long timing_get_timer( struct timing_hr_time *val, int reset )
{
    struct _hr_time *t = (struct _hr_time *) val;

    if( reset )
    {
        gettimeofday( &t->start, NULL );
        return( 0 );
    }
    else
    {
        unsigned long delta;
        struct timeval now;
        gettimeofday( &now, NULL );
        delta = ( now.tv_sec  - t->start.tv_sec  ) * 1000ul
              + ( now.tv_usec - t->start.tv_usec ) / 1000;
        return( delta );
    }
}

static void sighandler( int signum )
{
    timing_alarmed = 1;
    signal( signum, sighandler );
}

void set_alarm( int seconds )
{
    timing_alarmed = 0;
    signal( SIGALRM, sighandler );
    alarm( seconds );
    if( seconds == 0 )
    {
        /* alarm(0) cancelled any previous pending alarm, but the
           handler won't fire, so raise the flag straight away. */
        timing_alarmed = 1;
    }
}

#endif /* _WIN32 && !EFIX64 && !EFI32 */

/*
 * Set delays to watch
 */
void timing_set_delay( void *data, uint32_t int_ms, uint32_t fin_ms )
{
    timing_delay_context *ctx = (timing_delay_context *) data;

    ctx->int_ms = int_ms;
    ctx->fin_ms = fin_ms;

    if( fin_ms != 0 )
        (void) timing_get_timer( &ctx->timer, 1 );
}

/*
 * Get number of delays expired
 */
int timing_get_delay( void *data )
{
    timing_delay_context *ctx = (timing_delay_context *) data;
    unsigned long elapsed_ms;

    if( ctx->fin_ms == 0 )
        return( -1 );

    elapsed_ms = timing_get_timer( &ctx->timer, 0 );

    if( elapsed_ms >= ctx->fin_ms )
        return( 2 );

    if( elapsed_ms >= ctx->int_ms )
        return( 1 );

    return( 0 );
}