/** @file
  Helper functions for PCH SMM dispatcher.

Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials are licensed and made available under
the terms and conditions of the BSD License that accompanies this distribution.
The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php.

THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

**/
#include "PchSmmHelpers.h"

///
/// SUPPORT / HELPER FUNCTIONS (PCH version-independent)
///

/**
  Compare 2 SMM source descriptors' enable settings.

  @param[in] Src1                 Pointer to the PCH SMI source description table 1
  @param[in] Src2                 Pointer to the PCH SMI source description table 2

  @retval TRUE                    The enable settings of the 2 SMM source descriptors are identical.
  @retval FALSE                   The enable settings of the 2 SMM source descriptors are not identical.
**/
BOOLEAN
CompareEnables (
  CONST IN PCH_SMM_SOURCE_DESC *Src1,
  CONST IN PCH_SMM_SOURCE_DESC *Src2
  )
{
  BOOLEAN IsEqual;
  UINTN   DescIndex;

  IsEqual = TRUE;
  for (DescIndex = 0; DescIndex < NUM_EN_BITS; DescIndex++) {
    ///
    /// It's okay to compare a NULL bit description to a non-NULL bit description.
    /// They are unequal and these tests will generate the correct result.
    ///
    if (Src1->En[DescIndex].Bit != Src2->En[DescIndex].Bit ||
        Src1->En[DescIndex].Reg.Type != Src2->En[DescIndex].Reg.Type ||
        Src1->En[DescIndex].Reg.Data.raw != Src2->En[DescIndex].Reg.Data.raw
        ) {
      IsEqual = FALSE;
      break;
      ///
      /// out of for loop
      ///
    }
  }

  return IsEqual;
}

/**
  Compare a bit descriptor to the enables of source descriptor. Includes null address type.

  @param[in] BitDesc              Pointer to the PCH SMI bit descriptor
  @param[in] Src                  Pointer to the PCH SMI source description table 2

  @retval TRUE                    The bit desc is equal to any of the enables in source descriptor
  @retval FALSE                   The bid desc is not equal to all of the enables in source descriptor
**/
BOOLEAN
IsBitEqualToAnySourceEn (
  CONST IN PCH_SMM_BIT_DESC    *BitDesc,
  CONST IN PCH_SMM_SOURCE_DESC *Src
  )
{
  BOOLEAN IsEqual;
  UINTN   DescIndex;

  IsEqual = FALSE;

  for (DescIndex = 0; DescIndex < NUM_EN_BITS; ++DescIndex) {
    if ((BitDesc->Reg.Type == Src->En[DescIndex].Reg.Type) &&
        (BitDesc->Reg.Data.raw == Src->En[DescIndex].Reg.Data.raw) &&
        (BitDesc->Bit == Src->En[DescIndex].Bit)) {
      IsEqual = TRUE;
      break;
    }
  }
  return IsEqual;
}

/**
  Compare 2 SMM source descriptors' statuses.

  @param[in] Src1                 Pointer to the PCH SMI source description table 1
  @param[in] Src2                 Pointer to the PCH SMI source description table 2

  @retval TRUE                    The statuses of the 2 SMM source descriptors are identical.
  @retval FALSE                   The statuses of the 2 SMM source descriptors are not identical.
**/
BOOLEAN
CompareStatuses (
  CONST IN PCH_SMM_SOURCE_DESC *Src1,
  CONST IN PCH_SMM_SOURCE_DESC *Src2
  )
{
  BOOLEAN IsEqual;
  UINTN   DescIndex;

  IsEqual = TRUE;

  for (DescIndex = 0; DescIndex < NUM_STS_BITS; DescIndex++) {
    ///
    /// It's okay to compare a NULL bit description to a non-NULL bit description.
    /// They are unequal and these tests will generate the correct result.
    ///
    if (Src1->Sts[DescIndex].Bit != Src2->Sts[DescIndex].Bit ||
        Src1->Sts[DescIndex].Reg.Type != Src2->Sts[DescIndex].Reg.Type ||
        Src1->Sts[DescIndex].Reg.Data.raw != Src2->Sts[DescIndex].Reg.Data.raw
        ) {
      IsEqual = FALSE;
      break;
      ///
      /// out of for loop
      ///
    }
  }

  return IsEqual;
}

/**
  Compare 2 SMM source descriptors, based on Enable settings and Status settings of them.

  @param[in] Src1                 Pointer to the PCH SMI source description table 1
  @param[in] Src2                 Pointer to the PCH SMI source description table 2

  @retval TRUE                    The 2 SMM source descriptors are identical.
  @retval FALSE                   The 2 SMM source descriptors are not identical.
**/
BOOLEAN
CompareSources (
  CONST IN PCH_SMM_SOURCE_DESC *Src1,
  CONST IN PCH_SMM_SOURCE_DESC *Src2
  )
{
  return (BOOLEAN) (CompareEnables (Src1, Src2) && CompareStatuses (Src1, Src2));
}

/**
  Check if an SMM source is active.

  @param[in] Src                  Pointer to the PCH SMI source description table
  @param[in] SciEn                Indicate if SCI is enabled or not
  @param[in] SmiEnValue           Value from R_PCH_SMI_EN
  @param[in] SmiStsValue          Value from R_PCH_SMI_STS

  @retval TRUE                    It is active.
  @retval FALSE                   It is inactive.
**/
BOOLEAN
SourceIsActive (
  CONST IN PCH_SMM_SOURCE_DESC  *Src,
  CONST IN BOOLEAN              SciEn,
  CONST IN UINT32               SmiEnValue,
  CONST IN UINT32               SmiStsValue
  )
{
  UINTN   DescIndex;

  ///
  /// This source is dependent on SciEn, and SciEn == 1.  An ACPI OS is present,
  /// so we shouldn't do anything w/ this source until SciEn == 0.
  ///
  if ((Src->Flags == PCH_SMM_SCI_EN_DEPENDENT) && (SciEn)) {
    return FALSE;
  }

  ///
  /// Checking top level SMI status. If the status is not active, return false immediately
  ///
  if (!IS_BIT_DESC_NULL (Src->PmcSmiSts)) {
    if ((Src->PmcSmiSts.Reg.Type == ACPI_ADDR_TYPE) &&
        (Src->PmcSmiSts.Reg.Data.acpi == R_PCH_SMI_STS) &&
        ((SmiStsValue & (1u << Src->PmcSmiSts.Bit)) == 0)) {
      return FALSE;
    }
  }

  ///
  /// Read each bit desc from hardware and make sure it's a one
  ///
  for (DescIndex = 0; DescIndex < NUM_EN_BITS; DescIndex++) {
    if (!IS_BIT_DESC_NULL (Src->En[DescIndex])) {
      if ((Src->En[DescIndex].Reg.Type == ACPI_ADDR_TYPE) &&
          (Src->En[DescIndex].Reg.Data.acpi == R_PCH_SMI_EN) &&
          ((SmiEnValue & (1u << Src->En[DescIndex].Bit)) == 0)) {
        return FALSE;
      } else if (ReadBitDesc (&Src->En[DescIndex]) == 0) {
        return FALSE;
      }
    }
  }

  ///
  /// Read each bit desc from hardware and make sure it's a one
  ///
  for (DescIndex = 0; DescIndex < NUM_STS_BITS; DescIndex++) {
    if (!IS_BIT_DESC_NULL (Src->Sts[DescIndex])) {
      if ((Src->Sts[DescIndex].Reg.Type == ACPI_ADDR_TYPE) &&
          (Src->Sts[DescIndex].Reg.Data.acpi == R_PCH_SMI_STS) &&
          ((SmiStsValue & (1u << Src->Sts[DescIndex].Bit)) == 0)) {
        return FALSE;
      } else if (ReadBitDesc (&Src->Sts[DescIndex]) == 0) {
        return FALSE;
      }
    }
  }

  return TRUE;
}

/**
  Enable the SMI source event by set the SMI enable bit, this function would also clear SMI
  status bit to make initial state is correct

  @param[in] SrcDesc              Pointer to the PCH SMI source description table

**/
VOID
PchSmmEnableSource (
  CONST PCH_SMM_SOURCE_DESC *SrcDesc
  )
{
  UINTN DescIndex;

  ///
  /// Set enables to 1 by writing a 1
  ///
  for (DescIndex = 0; DescIndex < NUM_EN_BITS; DescIndex++) {
    if (!IS_BIT_DESC_NULL (SrcDesc->En[DescIndex])) {
      WriteBitDesc (&SrcDesc->En[DescIndex], 1, FALSE);
    }
  }
  ///
  /// Clear statuses to 0 by writing a 1
  ///
  for (DescIndex = 0; DescIndex < NUM_STS_BITS; DescIndex++) {
    if (!IS_BIT_DESC_NULL (SrcDesc->Sts[DescIndex])) {
      WriteBitDesc (&SrcDesc->Sts[DescIndex], 1, TRUE);
    }
  }
}

/**
  Disable the SMI source event by clear the SMI enable bit

  @param[in] SrcDesc              Pointer to the PCH SMI source description table

**/
VOID
PchSmmDisableSource (
  CONST PCH_SMM_SOURCE_DESC *SrcDesc
  )
{
  UINTN DescIndex;

  for (DescIndex = 0; DescIndex < NUM_EN_BITS; DescIndex++) {
    if (!IS_BIT_DESC_NULL (SrcDesc->En[DescIndex])) {
      WriteBitDesc (&SrcDesc->En[DescIndex], 0, FALSE);
    }
  }
}

/**
  Clear the SMI status bit by set the source bit of SMI status register

  @param[in] SrcDesc              Pointer to the PCH SMI source description table

**/
VOID
PchSmmClearSource (
  CONST PCH_SMM_SOURCE_DESC *SrcDesc
  )
{
  UINTN DescIndex;

  for (DescIndex = 0; DescIndex < NUM_STS_BITS; DescIndex++) {
    if (!IS_BIT_DESC_NULL (SrcDesc->Sts[DescIndex])) {
      WriteBitDesc (&SrcDesc->Sts[DescIndex], 1, TRUE);
    }
  }
}

/**
  Sets the source to a 1 and then waits for it to clear.
  Be very careful when calling this function -- it will not
  ASSERT.  An acceptable case to call the function is when
  waiting for the NEWCENTURY_STS bit to clear (which takes
  3 RTCCLKs).

  @param[in] SrcDesc              Pointer to the PCH SMI source description table

**/
VOID
PchSmmClearSourceAndBlock (
  CONST PCH_SMM_SOURCE_DESC *SrcDesc
  )
{
  UINTN   DescIndex;
  BOOLEAN IsSet;

  for (DescIndex = 0; DescIndex < NUM_STS_BITS; DescIndex++) {

    if (!IS_BIT_DESC_NULL (SrcDesc->Sts[DescIndex])) {
      ///
      /// Write the bit
      ///
      WriteBitDesc (&SrcDesc->Sts[DescIndex], 1, TRUE);

      ///
      /// Don't return until the bit actually clears.
      ///
      IsSet = TRUE;
      while (IsSet) {
        IsSet = ReadBitDesc (&SrcDesc->Sts[DescIndex]);
        ///
        /// IsSet will eventually clear -- or else we'll have
        /// an infinite loop.
        ///
      }
    }
  }
}