stefanberger / libtpms / #2022

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/*                                                                                */

/*                 Platform Authenticated Countdown Timer                                  */

/*                             Written by Ken Goldman                                */

/*                       IBM Thomas J. Watson Research Center                        */

/*            $Id: PlatformACT.c 1594 2020-03-26 22:15:48Z kgoldman $                */

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/********************************************************************************/

//** Includes

#include "Platform.h"

//** Functions

#if ACT_SUPPORT

//*** ActSignal()

// Function called when there is an ACT event to signal or unsignal

#ifndef __ACT_DISABLED        // libtpms added

static void ActSignal(P_ACT_DATA actData, int on)

{

    if(actData == NULL)

        return;

    // If this is to turn a signal on, don't do anything if it is already on. If this

    // is to turn the signal off, do it anyway because this might be for

    // initialization.

    if(on && (actData->signaled == TRUE))

        return;

    actData->signaled = (uint8_t)on;

    // If there is an action, then replace the "Do something" with the correct action.

    // It should test 'on' to see if it is turning the signal on or off.

    switch(actData->number)

    {

#  if RH_ACT_0

        case 0:  // Do something

            return;

#  endif

#  if RH_ACT_1

        case 1:  // Do something

            return;

#  endif

#  if RH_ACT_2

        case 2:  // Do something

            return;

#  endif

#  if RH_ACT_3

        case 3:  // Do something

            return;

#  endif

#  if RH_ACT_4

        case 4:  // Do something

            return;

#  endif

#  if RH_ACT_5

        case 5:  // Do something

            return;

#  endif

#  if RH_ACT_6

        case 6:  // Do something

            return;

#  endif

#  if RH_ACT_7

        case 7:  // Do something

            return;

#  endif

#  if RH_ACT_8

        case 8:  // Do something

            return;

#  endif

#  if RH_ACT_9

        case 9:  // Do something

            return;

#  endif

#  if RH_ACT_A

        case 0xA:  // Do something

            return;

#  endif

#  if RH_ACT_B

        case 0xB:

            // Do something

            return;

#  endif

#  if RH_ACT_C

        case 0xC:  // Do something

            return;

#  endif

#  if RH_ACT_D

        case 0xD:  // Do something

            return;

#  endif

#  if RH_ACT_E

        case 0xE:  // Do something

            return;

#  endif

#  if RH_ACT_F

        case 0xF:  // Do something

            return;

#  endif

        default:

            return;

    }

}

#endif                // libtpms added

//*** ActGetDataPointer()

static P_ACT_DATA ActGetDataPointer(uint32_t act)

{

#  define RETURN_ACT_POINTER(N) \

      if(0x##N == act)          \

          return &ACT_##N;

    FOR_EACH_ACT(RETURN_ACT_POINTER)

    return (P_ACT_DATA)NULL;

}

//*** _plat__ACT_GetImplemented()

// This function tests to see if an ACT is implemented. It is a belt and suspenders

// function because the TPM should not be calling to manipulate an ACT that is not

// implemented. However, this could help the simulator code which doesn't necessarily

// know if an ACT is implemented or not.

{

}

//*** _plat__ACT_GetRemaining()

// This function returns the remaining time. If an update is pending, 'newValue' is

// returned. Otherwise, the current counter value is returned. Note that since the

// timers keep running, the returned value can get stale immediately. The actual count

// value will be no greater than the returned value.

)

{

    //

    remain = actData->remaining;

    if(actData->pending)

        remain = actData->newValue;

    return remain;

}

//*** _plat__ACT_GetSignaled()

)

{

    //

    return (int)actData->signaled;

}

#ifndef __ACT_DISABLED        // libtpms added

//*** _plat__ACT_SetSignaled()

LIB_EXPORT void _plat__ACT_SetSignaled(uint32_t act, int on)

{

    ActSignal(ActGetDataPointer(act), on);

}

//*** _plat__ACT_GetPending()

LIB_EXPORT int _plat__ACT_GetPending(uint32_t act  //IN: number of ACT to check

)

{

    P_ACT_DATA actData = ActGetDataPointer(act);

    //

    if(actData == NULL)

        return 0;

    return (int)actData->pending;

}

//*** _plat__ACT_UpdateCounter()

// This function is used to write the newValue for the counter. If an update is

// pending, then no update occurs and the function returns FALSE. If 'setSignaled'

// is TRUE, then the ACT signaled state is SET and if 'newValue' is 0, nothing

// is posted.

LIB_EXPORT int _plat__ACT_UpdateCounter(uint32_t act,      // IN: ACT to update

                                        uint32_t newValue  // IN: the value to post

)

{

    P_ACT_DATA actData = ActGetDataPointer(act);

    //

    if(actData == NULL)

        // actData doesn't exist but pretend update is pending rather than indicate

        // that a retry is necessary.

        return TRUE;

    // if an update is pending then return FALSE so that there will be a retry

    if(actData->pending != 0)

        return FALSE;

    actData->newValue = newValue;

    actData->pending  = TRUE;

    return TRUE;

}

#endif                // libtpms added

//***_plat__ACT_EnableTicks()

// This enables and disables the processing of the once-per-second ticks. This should

// be turned off ('enable' = FALSE) by _TPM_Init and turned on ('enable' = TRUE) by

// TPM2_Startup() after all the initializations have completed.

{

#ifndef __ACT_DISABLED        // libtpms added

//*** ActDecrement()

// If 'newValue' is non-zero it is copied to 'remaining' and then 'newValue' is

// set to zero. Then 'remaining' is decremented by one if it is not already zero. If

// the value is decremented to zero, then the associated event is signaled. If setting

// 'remaining' causes it to be greater than 1, then the signal associated with the ACT

// is turned off.

static void ActDecrement(P_ACT_DATA actData)

{

    // Check to see if there is an update pending

    if(actData->pending)

    {

        // If this update will cause the count to go from non-zero to zero, set

        // the newValue to 1 so that it will timeout when decremented below.

        if((actData->newValue == 0) && (actData->remaining != 0))

            actData->newValue = 1;

        actData->remaining = actData->newValue;

        // Update processed

        actData->pending = 0;

    }

    // no update so countdown if the count is non-zero but not max

    if((actData->remaining != 0) && (actData->remaining != UINT32_MAX))

    {

        // If this countdown causes the count to go to zero, then turn the signal for

        // the ACT on.

        if((actData->remaining -= 1) == 0)

            ActSignal(actData, TRUE);

    }

    // If the current value of the counter is non-zero, then the signal should be

    // off.

    if(actData->signaled && (actData->remaining > 0))

        ActSignal(actData, FALSE);

}

//*** _plat__ACT_Tick()

// This processes the once-per-second clock tick from the hardware. This is set up

// for the simulator to use the control interface to send ticks to the TPM. These

// ticks do not have to be on a per second basis. They can be as slow or as fast as

// desired so that the simulation can be tested.

LIB_EXPORT void _plat__ACT_Tick(void)

{

    // Ticks processing is turned off at certain times just to make sure that nothing

    // strange is happening before pointers and things are

    if(actTicksAllowed)

    {

        // Handle the update for each counter.

#  define DECREMENT_COUNT(N) ActDecrement(&ACT_##N);

        FOR_EACH_ACT(DECREMENT_COUNT)

    }

}

//*** ActZero()

// This function initializes a single ACT

static void ActZero(uint32_t act, P_ACT_DATA actData)

{

    actData->remaining = 0;

    actData->newValue  = 0;

    actData->pending   = 0;

    actData->number    = (uint8_t)act;

    ActSignal(actData, FALSE);

}

#endif                        // libtpms added

//***_plat__ACT_Initialize()

// This function initializes the ACT hardware and data structures

{

#  define ZERO_ACT(N) ActZero(0x##N, &ACT_##N);

    FOR_EACH_ACT(ZERO_ACT)

}

#endif  // ACT_SUPPORT