Re: [edk2-devel] [edk2-staging/UEFI_PCI_ENHANCE-2 PATCH 07/12] PciBusDxe: New PCI Express feature Completion Timeout

["Javeed, Ashraf" <ashraf.javeed@intel.com>]

This patch can also be viewed in the following repo:-
https://github.com/ashrafj/edk2-staging/commit/7f0ea5bf87b220b8941bacac99f956948785571d

Thanks
Ashraf

> -----Original Message-----
> From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Javeed,
> Ashraf
> Sent: Saturday, February 8, 2020 1:35 AM
> To: devel@edk2.groups.io
> Cc: Wang, Jian J <jian.j.wang@intel.com>; Wu, Hao A <hao.a.wu@intel.com>;
> Ni, Ray <ray.ni@intel.com>
> Subject: [edk2-devel] [edk2-staging/UEFI_PCI_ENHANCE-2 PATCH 07/12]
> PciBusDxe: New PCI Express feature Completion Timeout
> 
> BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2313
> 
> The code changes are made; as per the PCI Express Base Specification 4 Revision
> 1; to enable the configuration of PCI Express feature Completion Timeout (CTO),
> that enables the PCI function to wait on programmed dura- tion for its
> transactions before timeout, or disable its detection mecha- nism.
> 
> The code changes are made to configure only those PCI devices which are
> requested by platform for override through the new PCI Express Platform
> protocol interface for device-specific policies. The changes are made to also
> comply with the device-specific capability attributes.
> 
> The code follows the below implementation specific rules in case the req-
> uested platform policy does not match with the device-specific capability
> attributes:-
> (1) if device is capable of Range A only and if platform ask for any of
>     ranges B, C, D; than this implementation will only program the default
>     range value for the duration of 50us to 50ms
> (2) if device is capable of Range B, or range B & C, or Ranges B, C & D
>     only and if the platform ask for the Range A; than this implementation
>     will only program the default range value for the duration of 50us to
>     50ms
> (3) if the device is capable of Range B only, or the ranges A & B; and if
>     the platform ask for Range C, or Range D values, than this implement-
>     ation will only program the Range B value for the duration of 65ms to
>     210ms
> (4) if the device is capable of Ranges B & C, or Ranges A, B, and C; and
>     if the platform ask for Range D values; than this implementation will
>     only program the Range C for the duration of 1s to 3.5s
> 
> Signed-off-by: Ashraf Javeed <ashraf.javeed@intel.com>
> Cc: Jian J Wang <jian.j.wang@intel.com>
> Cc: Hao A Wu <hao.a.wu@intel.com>
> Cc: Ray Ni <ray.ni@intel.com>
> ---
>  MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.h             |   1 +
>  MdeModulePkg/Bus/Pci/PciBusDxe/PciExpressFeatures.c | 387
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  MdeModulePkg/Bus/Pci/PciBusDxe/PciExpressFeatures.h |  35
> +++++++++++++++++++++++++++++++++++
>  MdeModulePkg/Bus/Pci/PciBusDxe/PciFeatureSupport.c  |   8 +++++++-
>  MdeModulePkg/Bus/Pci/PciBusDxe/PciPlatformSupport.c | 131
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> +
>  5 files changed, 561 insertions(+), 1 deletion(-)
> 
> diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.h
> b/MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.h
> index e610b52..9b03c12 100644
> --- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.h
> +++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.h
> @@ -294,6 +294,7 @@ struct _PCI_IO_DEVICE {
>    UINT8                                     SetupMRRS;
>    PCI_FEATURE_POLICY                        SetupRO;
>    PCI_FEATURE_POLICY                        SetupNS;
> +  PCI_FEATURE_POLICY                        SetupCTO;
>  };
> 
>  #define PCI_IO_DEVICE_FROM_PCI_IO_THIS(a) \ diff --git
> a/MdeModulePkg/Bus/Pci/PciBusDxe/PciExpressFeatures.c
> b/MdeModulePkg/Bus/Pci/PciBusDxe/PciExpressFeatures.c
> index df85366..f3f4d39 100644
> --- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciExpressFeatures.c
> +++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciExpressFeatures.c
> @@ -521,3 +521,390 @@ ProgramNoSnoop (
>    return Status;
>  }
> 
> +/**
> +  To determine the CTO Range A values
> +
> +  @param  CtoValue    input CTO range value from 0 to 14
> +  @retval TRUE        the given CTO value belongs to Range A
> +          FALSE       the given value does not belong to Range A
> +**/
> +BOOLEAN
> +IsCtoRangeA (
> +  IN  UINT8   CtoValue
> +  )
> +{
> +  switch (CtoValue) {
> +    case  PCIE_COMPLETION_TIMEOUT_50US_100US:
> +    case  PCIE_COMPLETION_TIMEOUT_1MS_10MS:
> +      return TRUE;
> +  }
> +  return FALSE;
> +}
> +
> +/**
> +  To determine the CTO Range B values
> +
> +  @param  CtoValue    input CTO range value from 0 to 14
> +  @retval TRUE        the given CTO value belongs to Range B
> +          FALSE       the given value does not belong to Range B
> +**/
> +BOOLEAN
> +IsCtoRangeB (
> +  IN  UINT8   CtoValue
> +  )
> +{
> +  switch (CtoValue) {
> +    case  PCIE_COMPLETION_TIMEOUT_16MS_55MS:
> +    case  PCIE_COMPLETION_TIMEOUT_65MS_210MS:
> +      return TRUE;
> +  }
> +  return FALSE;
> +}
> +
> +/**
> +  To determine the CTO Range C values
> +
> +  @param  CtoValue    input CTO range value from 0 to 14
> +  @retval TRUE        the given CTO value belongs to Range C
> +          FALSE       the given value does not belong to Range C
> +**/
> +BOOLEAN
> +IsCtoRangeC (
> +  IN  UINT8   CtoValue
> +  )
> +{
> +  switch (CtoValue) {
> +    case  PCIE_COMPLETION_TIMEOUT_260MS_900MS:
> +    case  PCIE_COMPLETION_TIMEOUT_1S_3_5S:
> +      return TRUE;
> +  }
> +  return FALSE;
> +}
> +
> +/**
> +  To determine the CTO Range D values
> +
> +  @param  CtoValue    input CTO range value from 0 to 14
> +  @retval TRUE        the given CTO value belongs to Range D
> +          FALSE       the given value does not belong to Range D
> +**/
> +BOOLEAN
> +IsCtoRangeD (
> +  IN  UINT8   CtoValue
> +  )
> +{
> +  switch (CtoValue) {
> +    case  PCIE_COMPLETION_TIMEOUT_4S_13S:
> +    case  PCIE_COMPLETION_TIMEOUT_17S_64S:
> +      return TRUE;
> +  }
> +  return FALSE;
> +}
> +
> +/**
> +  The main routine which setup the PCI feature Completion Timeout as
> +per the
> +  device-specific platform policy, as well as in complaince with the
> +PCI Base
> +  specification Revision 4.
> +
> +  @param PciDevice                      A pointer to the PCI_IO_DEVICE.
> +
> +  @retval EFI_SUCCESS                   processing of PCI feature CTO is successful.
> +**/
> +EFI_STATUS
> +SetupCompletionTimeout (
> +  IN PCI_IO_DEVICE          *PciDevice,
> +  IN VOID                   *PciExFeatureConfiguration
> +  )
> +{
> +  PCI_REG_PCIE_DEVICE_CAPABILITY2 DeviceCap2;
> +  UINT8                           CtoRangeValue;
> +
> +  if (!PciDevice->SetupCTO.Override) {
> +    //
> +    // No override of CTO is required for this device
> +    //
> +    return  EFI_SUCCESS;
> +  }
> +
> +  //
> +  // determine the CTO range values as per its device capability
> + register  //
> +  DeviceCap2.Uint32 =
> + PciDevice->PciExpressCapabilityStructure.DeviceCapability2.Uint32;
> +  if (!DeviceCap2.Bits.CompletionTimeoutRanges
> +      && !DeviceCap2.Bits.CompletionTimeoutDisable
> +  ) {
> +    //
> +    // device does not support the CTO mechanism, hence no override is
> applicable
> +    //
> +    return EFI_SUCCESS;
> +  }
> +
> +  //
> +  // override the device CTO values if applicable  //  if
> + (PciDevice->SetupCTO.Act) {
> +    //
> +    // program the CTO range values
> +    //
> +    if (DeviceCap2.Bits.CompletionTimeoutRanges) {
> +      CtoRangeValue = PCIE_COMPLETION_TIMEOUT_50US_50MS;
> +      //
> +      // in case if the supported CTO range and the requirement from platform
> +      // policy does not match, than the CTO range setting would be based on
> +      // this driver's implementation specific, and its rules are as follows:-
> +      //
> +      // if device is capable of Range A only and if platform ask for any of
> +      // ranges B, C, D; than this implementation will only program the default
> +      // range value for the duration of 50us to 50ms.
> +      //
> +      // if device is capable of Range B, or range B & C, or Ranges B, C & D only
> +      // and if the platform ask for the Range A; than this implementation will
> +      // only program the default range value for the duration of 50us to 50ms.
> +      //
> +      // if the device is capable of Range B only, or the ranges A & B; and the
> +      // platform ask for Range C, or Range D values, than this implementation
> +      // will only program the Range B value for the duration of 65ms to 210ms.
> +      //
> +      // if the device is capable of Ranges B & C, or Ranges A, B, and C; and
> +      // if the platform ask for Range D values; than this implementation will
> +      // only program the Range C for the duration of 1s to 3.5s.
> +      //
> +
> +      switch (DeviceCap2.Bits.CompletionTimeoutRanges) {
> +        case  PCIE_COMPLETION_TIMEOUT_RANGE_A_SUPPORTED:
> +          if (IsCtoRangeA (PciDevice->SetupCTO.Support)) {
> +            CtoRangeValue = PciDevice->SetupCTO.Support;
> +          }
> +          //
> +          // if device is capable of Range A only and if platform ask for any of
> +          // ranges B, C, D; than this implementation will only program the default
> +          // range value for the duration of 50us to 50ms.
> +          //
> +          if (IsCtoRangeB (PciDevice->SetupCTO.Support)
> +              || IsCtoRangeC (PciDevice->SetupCTO.Support)
> +              || IsCtoRangeD (PciDevice->SetupCTO.Support)
> +          ) {
> +            CtoRangeValue = PCIE_COMPLETION_TIMEOUT_50US_50MS;
> +          }
> +          break;
> +
> +        case  PCIE_COMPLETION_TIMEOUT_RANGE_B_SUPPORTED:
> +          //
> +          // if device is capable of Range B, or range B & C, or Ranges B, C & D only
> +          // and if the platform ask for the Range A; than this implementation will
> +          // only program the default range value for the duration of 50us to 50ms.
> +          //
> +          if (IsCtoRangeA (PciDevice->SetupCTO.Support)) {
> +            CtoRangeValue = PCIE_COMPLETION_TIMEOUT_50US_50MS;
> +          }
> +
> +          if (IsCtoRangeB (PciDevice->SetupCTO.Support)) {
> +            CtoRangeValue = PciDevice->SetupCTO.Support;
> +          }
> +          //
> +          // if the device is capable of Range B only, or the ranges A & B; and the
> +          // platform ask for Range C, or Range D values, than this implementation
> +          // will only program the Range B value for the duration of 65ms to
> 210ms.
> +          //
> +          if (IsCtoRangeC (PciDevice->SetupCTO.Support)
> +              || IsCtoRangeD (PciDevice->SetupCTO.Support)
> +          ) {
> +            CtoRangeValue = PCIE_COMPLETION_TIMEOUT_65MS_210MS;
> +          }
> +          break;
> +
> +        case  PCIE_COMPLETION_TIMEOUT_RANGE_B_C_SUPPORTED:
> +          if (IsCtoRangeA (PciDevice->SetupCTO.Support)) {
> +            CtoRangeValue = PCIE_COMPLETION_TIMEOUT_50US_50MS;
> +          }
> +
> +          if (IsCtoRangeB (PciDevice->SetupCTO.Support)
> +              || IsCtoRangeC (PciDevice->SetupCTO.Support)
> +              ) {
> +            CtoRangeValue = PciDevice->SetupCTO.Support;
> +          }
> +          //
> +          // if the device is capable of Ranges B & C, or Ranges A, B, and C; and
> +          // if the platform ask for Range D values; than this implementation will
> +          // only program the Range C for the duration of 1s to 3.5s.
> +          //
> +          if (IsCtoRangeD (PciDevice->SetupCTO.Support)) {
> +            CtoRangeValue = PCIE_COMPLETION_TIMEOUT_1S_3_5S;
> +          }
> +          break;
> +
> +        case  PCIE_COMPLETION_TIMEOUT_RANGE_B_C_D_SUPPORTED:
> +          if (IsCtoRangeA (PciDevice->SetupCTO.Support)) {
> +            CtoRangeValue = PCIE_COMPLETION_TIMEOUT_50US_50MS;
> +          }
> +          if (IsCtoRangeB (PciDevice->SetupCTO.Support)
> +              || IsCtoRangeC (PciDevice->SetupCTO.Support)
> +              || IsCtoRangeD (PciDevice->SetupCTO.Support)
> +          ) {
> +            CtoRangeValue = PciDevice->SetupCTO.Support;
> +          }
> +          break;
> +
> +        case  PCIE_COMPLETION_TIMEOUT_RANGE_A_B_SUPPORTED:
> +          if (IsCtoRangeA (PciDevice->SetupCTO.Support)
> +              || IsCtoRangeB (PciDevice->SetupCTO.Support)
> +              ) {
> +            CtoRangeValue = PciDevice->SetupCTO.Support;
> +          }
> +          if (IsCtoRangeC (PciDevice->SetupCTO.Support)
> +              || IsCtoRangeD (PciDevice->SetupCTO.Support)
> +          ) {
> +            CtoRangeValue = PCIE_COMPLETION_TIMEOUT_65MS_210MS;
> +          }
> +          break;
> +
> +        case  PCIE_COMPLETION_TIMEOUT_RANGE_A_B_C_SUPPORTED:
> +          if (IsCtoRangeA (PciDevice->SetupCTO.Support)
> +              || IsCtoRangeB (PciDevice->SetupCTO.Support)
> +              || IsCtoRangeC (PciDevice->SetupCTO.Support)
> +          ) {
> +            CtoRangeValue = PciDevice->SetupCTO.Support;
> +          }
> +          if (IsCtoRangeD (PciDevice->SetupCTO.Support)) {
> +            CtoRangeValue = PCIE_COMPLETION_TIMEOUT_1S_3_5S;
> +          }
> +          break;
> +
> +        case  PCIE_COMPLETION_TIMEOUT_RANGE_A_B_C_D_SUPPORTED:
> +          if (IsCtoRangeA (PciDevice->SetupCTO.Support)
> +              || IsCtoRangeB (PciDevice->SetupCTO.Support)
> +              || IsCtoRangeC (PciDevice->SetupCTO.Support)
> +              || IsCtoRangeD (PciDevice->SetupCTO.Support)
> +          ) {
> +            CtoRangeValue = PciDevice->SetupCTO.Support;
> +          }
> +          break;
> +
> +        default:
> +          DEBUG ((
> +            DEBUG_ERROR,
> +            "Invalid CTO range: %d\n",
> +            DeviceCap2.Bits.CompletionTimeoutRanges
> +            ));
> +          return EFI_INVALID_PARAMETER;
> +      }
> +
> +      if (PciDevice->SetupCTO.Support != CtoRangeValue) {
> +        PciDevice->SetupCTO.Support = CtoRangeValue;
> +      }
> +    }
> +    DEBUG (( DEBUG_INFO, "CTO enable: %d, CTO range: 0x%x,",
> +        PciDevice->SetupCTO.Act,
> +        PciDevice->SetupCTO.Support
> +    ));
> +  }
> +  return EFI_SUCCESS;
> +}
> +
> +/**
> +  Overrides the PCI Device Control2 register Completion Timeout range;
> +if
> +  the hardware value is different than the intended value.
> +
> +  @param  PciDevice             A pointer to the PCI_IO_DEVICE instance.
> +
> +  @retval EFI_SUCCESS           The data was read from or written to the PCI
> device.
> +  @retval EFI_UNSUPPORTED       The address range specified by Offset, Width,
> and Count is not
> +                                valid for the PCI configuration header of the PCI controller.
> +  @retval EFI_INVALID_PARAMETER Buffer is NULL or Width is invalid.
> +
> +**/
> +EFI_STATUS
> +ProgramCompletionTimeout (
> +  IN PCI_IO_DEVICE          *PciDevice,
> +  IN VOID                   *PciExFeatureConfiguration
> +  )
> +{
> +  PCI_REG_PCIE_DEVICE_CONTROL2    DeviceCtl2;
> +  PCI_REG_PCIE_DEVICE_CAPABILITY2 DeviceCap2;
> +  UINT32                          Offset;
> +  EFI_STATUS                      Status;
> +  EFI_TPL                         OldTpl;
> +
> +  if (!PciDevice->SetupCTO.Override) {
> +    //
> +    // No override of CTO is required for this device
> +    //
> +    DEBUG (( DEBUG_INFO, "CTO skipped,"));
> +    return  EFI_SUCCESS;
> +  }
> +
> +  //
> +  // to program the CTO range values, determine in its device
> + capability register  //
> +  DeviceCap2.Uint32 =
> + PciDevice->PciExpressCapabilityStructure.DeviceCapability2.Uint32;
> +  if (DeviceCap2.Bits.CompletionTimeoutRanges
> +      || DeviceCap2.Bits.CompletionTimeoutDisable) {
> +    //
> +    // device supports the CTO mechanism
> +    //
> +    DeviceCtl2.Uint16 = 0;
> +    Offset = PciDevice->PciExpressCapabilityOffset +
> +              OFFSET_OF (PCI_CAPABILITY_PCIEXP, DeviceControl2);
> +    Status = PciDevice->PciIo.Pci.Read (
> +                                  &PciDevice->PciIo,
> +                                  EfiPciIoWidthUint16,
> +                                  Offset,
> +                                  1,
> +                                  &DeviceCtl2.Uint16
> +                                  );
> +    ASSERT (Status == EFI_SUCCESS);
> +  } else {
> +    //
> +    // device does not support the CTO mechanism, hence no override
> performed
> +    //
> +    DEBUG (( DEBUG_INFO, "CTO n/a,"));
> +    return EFI_SUCCESS;
> +  }
> +
> +  //
> +  // override the device CTO values if applicable  //  if
> + (PciDevice->SetupCTO.Act) {
> +    //
> +    // program the CTO range values
> +    //
> +    if (PciDevice->SetupCTO.Support !=
> DeviceCtl2.Bits.CompletionTimeoutValue) {
> +      DeviceCtl2.Bits.CompletionTimeoutValue = PciDevice->SetupCTO.Support;
> +    }
> +  } else {
> +    //
> +    // disable the CTO mechanism in device
> +    //
> +    DeviceCtl2.Bits.CompletionTimeoutValue = 0;
> +    DeviceCtl2.Bits.CompletionTimeoutDisable = 1;  }  DEBUG ((
> + DEBUG_INFO, "CTO disable: %d, CTO range: 0x%x,",
> +      DeviceCtl2.Bits.CompletionTimeoutDisable,
> +      DeviceCtl2.Bits.CompletionTimeoutValue
> +  ));
> +
> +  //
> +  // Raise TPL to high level to disable timer interrupt while the write
> + operation completes  //  OldTpl = gBS->RaiseTPL (TPL_HIGH_LEVEL);
> +
> +  Status = PciDevice->PciIo.Pci.Write (
> +                                &PciDevice->PciIo,
> +                                EfiPciIoWidthUint16,
> +                                Offset,
> +                                1,
> +                                &DeviceCtl2.Uint16
> +                                );
> +  //
> +  // Restore TPL to its original level
> +  //
> +  gBS->RestoreTPL (OldTpl);
> +
> +  if (!EFI_ERROR(Status)) {
> +    PciDevice->PciExpressCapabilityStructure.DeviceControl2.Uint16 =
> +DeviceCtl2.Uint16;
> +  } else {
> +    ReportPciWriteError (PciDevice->BusNumber, PciDevice->DeviceNumber,
> +PciDevice->FunctionNumber, Offset);
> +  }
> +  return Status;
> +}
> +
> diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciExpressFeatures.h
> b/MdeModulePkg/Bus/Pci/PciBusDxe/PciExpressFeatures.h
> index ee636ce..2ee7d4d 100644
> --- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciExpressFeatures.h
> +++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciExpressFeatures.h
> @@ -133,4 +133,39 @@ ProgramNoSnoop (
>    IN VOID                   *PciExFeatureConfiguration
>    );
> 
> +/**
> +  The main routine which process the PCI feature Completion Timeout as
> +per the
> +  device-specific platform policy, as well as in complaince with the
> +PCI Base
> +  specification Revision 4.
> +
> +  @param PciDevice                      A pointer to the PCI_IO_DEVICE.
> +  @param PciConfigPhase                 for the PCI feature configuration phases:
> +                                        PciExpressFeatureSetupPhase &
> + PciExpressFeatureEntendedSetupPhase
> +
> +  @retval EFI_SUCCESS                   processing of PCI feature CTO is successful.
> +**/
> +EFI_STATUS
> +SetupCompletionTimeout (
> +  IN PCI_IO_DEVICE          *PciDevice,
> +  IN VOID                   *PciExFeatureConfiguration
> +  );
> +
> +/**
> +  Overrides the PCI Device Control2 register Completion Timeout range;
> +if
> +  the hardware value is different than the intended value.
> +
> +  @param  PciDevice             A pointer to the PCI_IO_DEVICE instance.
> +
> +  @retval EFI_SUCCESS           The data was read from or written to the PCI
> device.
> +  @retval EFI_UNSUPPORTED       The address range specified by Offset, Width,
> and Count is not
> +                                valid for the PCI configuration header of the PCI controller.
> +  @retval EFI_INVALID_PARAMETER Buffer is NULL or Width is invalid.
> +
> +**/
> +EFI_STATUS
> +ProgramCompletionTimeout (
> +  IN PCI_IO_DEVICE          *PciDevice,
> +  IN VOID                   *PciExFeatureConfiguration
> +  );
> +
>  #endif
> diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciFeatureSupport.c
> b/MdeModulePkg/Bus/Pci/PciBusDxe/PciFeatureSupport.c
> index d264d13..d4459f3 100644
> --- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciFeatureSupport.c
> +++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciFeatureSupport.c
> @@ -74,7 +74,7 @@ EFI_PCI_EXPRESS_PLATFORM_POLICY
> mPciExpressPlatformPolicy = {
>      //
>      // support for PCI Express feature - Completion Timeout
>      //
> -    FALSE,
> +    TRUE,
>      //
>      // support for PCI Express feature - Clock Power Management
>      //
> @@ -119,6 +119,12 @@ PCI_EXPRESS_FEATURE_INITIALIZATION_POINT
> mPciExpressFeatureInitializationList[]
>    },
>    {
>      PciExpressFeatureProgramPhase,        PciExpressNoSnoop,
> ProgramNoSnoop
> +  },
> +  {
> +    PciExpressFeatureSetupPhase,          PciExpressCto,
> SetupCompletionTimeout
> +  },
> +  {
> +    PciExpressFeatureProgramPhase,        PciExpressCto,
> ProgramCompletionTimeout
>    }
>  };
> 
> diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciPlatformSupport.c
> b/MdeModulePkg/Bus/Pci/PciBusDxe/PciPlatformSupport.c
> index 954ce16..1afea19 100644
> --- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciPlatformSupport.c
> +++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciPlatformSupport.c
> @@ -228,6 +228,85 @@ SetDevicePolicyPciExpressNs (
>    }
>  }
> 
> +/**
> +  Routine to set the device-specific policy for the PCI feature CTO
> +value range
> +  or disable
> +
> +  @param  CtoSupport    value corresponding to data type
> EFI_PCI_EXPRESS_CTO_SUPPORT
> +  @param  PciDevice     A pointer to PCI_IO_DEVICE
> +**/
> +VOID
> +SetDevicePolicyPciExpressCto (
> +  IN  EFI_PCI_EXPRESS_CTO_SUPPORT    CtoSupport,
> +  OUT PCI_IO_DEVICE               *PciDevice
> +)
> +{
> +  //
> +  // implementation specific rules for the usage of PCI_FEATURE_POLICY
> +members
> +  // exclusively for the PCI Feature CTO
> +  //
> +  // .Override = 0 to skip this PCI feature CTO for the PCI device
> +  // .Override = 1 to program this CTO PCI feature
> +  //      .Act = 1 to program the CTO range as per given device policy in .Support
> +  //      .Act = 0 to disable the CTO mechanism in the PCI device, CTO set to
> default range
> +  //
> +  switch (CtoSupport) {
> +    case  EFI_PCI_EXPRESS_CTO_AUTO:
> +      PciDevice->SetupCTO.Override = 0;
> +      break;
> +    case  EFI_PCI_EXPRESS_CTO_DEFAULT:
> +      PciDevice->SetupCTO.Override = 1;
> +      PciDevice->SetupCTO.Act = 1;
> +      PciDevice->SetupCTO.Support =
> PCIE_COMPLETION_TIMEOUT_50US_50MS;
> +      break;
> +    case  EFI_PCI_EXPRESS_CTO_RANGE_A1:
> +      PciDevice->SetupCTO.Override = 1;
> +      PciDevice->SetupCTO.Act = 1;
> +      PciDevice->SetupCTO.Support =
> PCIE_COMPLETION_TIMEOUT_50US_100US;
> +      break;
> +    case  EFI_PCI_EXPRESS_CTO_RANGE_A2:
> +      PciDevice->SetupCTO.Override = 1;
> +      PciDevice->SetupCTO.Act = 1;
> +      PciDevice->SetupCTO.Support = PCIE_COMPLETION_TIMEOUT_1MS_10MS;
> +      break;
> +    case  EFI_PCI_EXPRESS_CTO_RANGE_B1:
> +      PciDevice->SetupCTO.Override = 1;
> +      PciDevice->SetupCTO.Act = 1;
> +      PciDevice->SetupCTO.Support =
> PCIE_COMPLETION_TIMEOUT_16MS_55MS;
> +      break;
> +    case  EFI_PCI_EXPRESS_CTO_RANGE_B2:
> +      PciDevice->SetupCTO.Override = 1;
> +      PciDevice->SetupCTO.Act = 1;
> +      PciDevice->SetupCTO.Support =
> PCIE_COMPLETION_TIMEOUT_65MS_210MS;
> +      break;
> +    case  EFI_PCI_EXPRESS_CTO_RANGE_C1:
> +      PciDevice->SetupCTO.Override = 1;
> +      PciDevice->SetupCTO.Act = 1;
> +      PciDevice->SetupCTO.Support =
> PCIE_COMPLETION_TIMEOUT_260MS_900MS;
> +      break;
> +    case  EFI_PCI_EXPRESS_CTO_RANGE_C2:
> +      PciDevice->SetupCTO.Override = 1;
> +      PciDevice->SetupCTO.Act = 1;
> +      PciDevice->SetupCTO.Support = PCIE_COMPLETION_TIMEOUT_1S_3_5S;
> +      break;
> +    case  EFI_PCI_EXPRESS_CTO_RANGE_D1:
> +      PciDevice->SetupCTO.Override = 1;
> +      PciDevice->SetupCTO.Act = 1;
> +      PciDevice->SetupCTO.Support = PCIE_COMPLETION_TIMEOUT_4S_13S;
> +      break;
> +    case  EFI_PCI_EXPRESS_CTO_RANGE_D2:
> +      PciDevice->SetupCTO.Override = 1;
> +      PciDevice->SetupCTO.Act = 1;
> +      PciDevice->SetupCTO.Support = PCIE_COMPLETION_TIMEOUT_17S_64S;
> +      break;
> +    case  EFI_PCI_EXPRESS_CTO_DET_DISABLE:
> +      PciDevice->SetupCTO.Override = 1;
> +      PciDevice->SetupCTO.Act = 0;
> +      PciDevice->SetupCTO.Support =
> PCIE_COMPLETION_TIMEOUT_50US_50MS;
> +      break;
> +  }
> +}
> +
>  /**
>    Generic routine to setup the PCI features as per its predetermined defaults.
>  **/
> @@ -253,6 +332,8 @@ SetupDefaultPciExpressDevicePolicy (
> 
>    PciDevice->SetupNS.Override = 0;
> 
> +  PciDevice->SetupCTO.Override = 0;
> +
>  }
> 
>  /**
> @@ -360,6 +441,15 @@ GetPciExpressDevicePolicy (
>        PciDevice->SetupNS.Override = 0;
>      }
> 
> +    //
> +    // set the device specific policy for Completion Timeout (CTO)
> +    //
> +    if (mPciExpressPlatformPolicy.Cto) {
> +      SetDevicePolicyPciExpressCto (PciExpressDevicePolicy.CTOsupport,
> PciDevice);
> +    } else {
> +      PciDevice->SetupCTO.Override = 0;
> +    }
> +
> 
>      DEBUG ((
>        DEBUG_INFO,
> @@ -498,6 +588,34 @@ GetPciExpressMrrs (
>    return EFI_PCI_EXPRESS_NOT_APPLICABLE;  }
> 
> +EFI_PCI_EXPRESS_CTO_SUPPORT
> +GetPciExpressCto (
> +  IN UINT8              Cto
> +  )
> +{
> +  switch (Cto) {
> +    case PCIE_COMPLETION_TIMEOUT_50US_50MS:
> +      return EFI_PCI_EXPRESS_CTO_DEFAULT;
> +    case PCIE_COMPLETION_TIMEOUT_50US_100US:
> +      return EFI_PCI_EXPRESS_CTO_RANGE_A1;
> +    case PCIE_COMPLETION_TIMEOUT_1MS_10MS:
> +      return EFI_PCI_EXPRESS_CTO_RANGE_A2;
> +    case PCIE_COMPLETION_TIMEOUT_16MS_55MS:
> +      return EFI_PCI_EXPRESS_CTO_RANGE_B1;
> +    case PCIE_COMPLETION_TIMEOUT_65MS_210MS:
> +      return EFI_PCI_EXPRESS_CTO_RANGE_B2;
> +    case PCIE_COMPLETION_TIMEOUT_260MS_900MS:
> +      return EFI_PCI_EXPRESS_CTO_RANGE_C1;
> +    case PCIE_COMPLETION_TIMEOUT_1S_3_5S:
> +      return EFI_PCI_EXPRESS_CTO_RANGE_C2;
> +    case PCIE_COMPLETION_TIMEOUT_4S_13S:
> +      return EFI_PCI_EXPRESS_CTO_RANGE_D1;
> +    case PCIE_COMPLETION_TIMEOUT_17S_64S:
> +      return EFI_PCI_EXPRESS_CTO_RANGE_D2;
> +  }
> +  return EFI_PCI_EXPRESS_NOT_APPLICABLE; }
> +
> 
>  /**
>    Notifies the platform about the current PCI Express state of the device.
> @@ -561,6 +679,19 @@ PciExpressPlatformNotifyDeviceState (
>      PciExDeviceConfiguration.DeviceCtlNoSnoop =
> EFI_PCI_EXPRESS_NOT_APPLICABLE;
>    }
> 
> +  //
> +  // get the device-specific state for the PCIe CTO feature  //  if
> + (mPciExpressPlatformPolicy.Cto) {
> +    PciExDeviceConfiguration.CTOsupport = PciDevice-
> >PciExpressCapabilityStructure.DeviceControl2.Bits.CompletionTimeoutDisable
> +                                          ? EFI_PCI_EXPRESS_CTO_DET_DISABLE
> +                                          : GetPciExpressCto (
> +                                              (UINT8)PciDevice-
> >PciExpressCapabilityStructure.DeviceControl2.Bits.CompletionTimeoutValue
> +                                              );  } else {
> +    PciExDeviceConfiguration.CTOsupport =
> + EFI_PCI_EXPRESS_NOT_APPLICABLE;  }
> +
> 
>    if (mPciExPlatformProtocol != NULL) {
>      return mPciExPlatformProtocol->NotifyDeviceState (
> --
> 2.21.0.windows.1
> 
> 
>