Re: [edk2-devel] [edk2-staging/UEFI_PCI_ENHANCE-2 PATCH V2] MdePkg/Protocols: New interface, EFI encodings to PCI Plat protocol

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

Remote repository:- https://github.com/ashrafj/edk2-staging
This commit:- https://github.com/ashrafj/edk2-staging/commit/be59cc61f29a67d1bc28a768f3673143b02a7a21

Thanks
Ashraf

> -----Original Message-----
> From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Javeed,
> Ashraf
> Sent: Monday, July 29, 2019 12:22 PM
> To: devel@edk2.groups.io
> Cc: Kinney, Michael D <michael.d.kinney@intel.com>; Gao, Liming
> <liming.gao@intel.com>; Ni, Ray <ray.ni@intel.com>
> Subject: [edk2-devel] [edk2-staging/UEFI_PCI_ENHANCE-2 PATCH V2]
> MdePkg/Protocols: New interface, EFI encodings to PCI Plat protocol
> 
> BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=1954
> 
> New interface added to PCI Platform Protocol / PCI Override Protocol to
> retrieve device-specific platform policy for the following PCI standard features,
> like Maximum Payload Size (MPS), Maximum Read Request Size
> (MRRS),Extended Tags, Relax Order, No-Snoop, Active State Power
> Management (ASPM),Latency Time Reporting (LTR), AtomicOp, Reference Clock
> Configuration, Extended SYNCH, PTM support, and Completion Timeout (CTO).
> New source files added with enhanced definitions are in:
> MdePkg/Include/Protocol/PciPlatform2.h,
> MdePkg/Include/Protocol/PciOverride2.h
> 
> Signed-off-by: Ashraf Javeed <ashraf.javeed@intel.com>
> Cc: Michael D Kinney <michael.d.kinney@intel.com>
> Cc: Liming Gao <liming.gao@intel.com>
> Cc: Ray Ni <ray.ni@intel.com>
> ---
> 
> In V2: Correction made to header sections of source files
> ---
>  MdePkg/Include/Protocol/PciOverride2.h |  43
> +++++++++++++++++++++++++++++++++++++++++++
>  MdePkg/Include/Protocol/PciPlatform2.h | 393
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> +++
>  MdePkg/MdePkg.dec                      |   6 ++++++
>  3 files changed, 442 insertions(+)
> 
> diff --git a/MdePkg/Include/Protocol/PciOverride2.h
> b/MdePkg/Include/Protocol/PciOverride2.h
> new file mode 100644
> index 0000000000..a7f541b4c3
> --- /dev/null
> +++ b/MdePkg/Include/Protocol/PciOverride2.h
> @@ -0,0 +1,43 @@
> +/** @file
> +  This file declares EFI PCI Override protocol which provides the
> +interface between
> +  the PCI bus driver/PCI Host Bridge Resource Allocation driver and an
> +implementation's
> +  driver to describe the unique features of a platform.
> +  This protocol is optional.
> +
> +  Copyright (c) 2019, 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  which
> + 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.
> +
> +
> +**/
> +
> +#ifndef _PCI_OVERRIDE2_H_
> +#define _PCI_OVERRIDE2_H_
> +
> +///
> +/// EFI_PCI_OVERRIDE_PROTOCOL has the same structure with
> +EFI_PCI_PLATFORM_PROTOCOL /// #include <Protocol/PciPlatform2.h>
> +
> +///
> +/// Global ID for the EFI_PCI_OVERRIDE_PROTOCOL /// #define
> +EFI_PCI_OVERRIDE2_GUID \
> +  { \
> +    0xb9d5ea1, 0x66cb, 0x4546, {0xb0, 0xbb, 0x5c, 0x6d, 0xae, 0xd9,
> +0x42, 0x47} \
> +  }
> +
> +///
> +/// Declaration for EFI_PCI_OVERRIDE_PROTOCOL /// typedef
> +EFI_PCI_PLATFORM_PROTOCOL2 EFI_PCI_OVERRIDE_PROTOCOL2;
> +
> +
> +extern EFI_GUID   gEfiPciOverrideProtocol2Guid;
> +
> +#endif
> diff --git a/MdePkg/Include/Protocol/PciPlatform2.h
> b/MdePkg/Include/Protocol/PciPlatform2.h
> new file mode 100644
> index 0000000000..717938e68d
> --- /dev/null
> +++ b/MdePkg/Include/Protocol/PciPlatform2.h
> @@ -0,0 +1,393 @@
> +/** @file
> +  This file declares PCI Platform Protocol that provide the interface
> +between
> +  the PCI bus driver/PCI Host Bridge Resource Allocation driver and a
> +platform-specific
> +  driver to describe the unique features of a platform.
> +  This protocol is optional.
> +
> +Copyright (c) 2019, 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.
> +
> +
> +**/
> +
> +#ifndef _PCI_PLATFORM2_H_
> +#define _PCI_PLATFORM2_H_
> +
> +///
> +/// This file must be included because the EFI_PCI_PLATFORM_PROTOCOL2
> +uses /// EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PHASE.
> +///
> +#include <Protocol/PciHostBridgeResourceAllocation.h>
> +
> +///
> +/// Reuse the existing definition to maintain backward compatibility
> +/// #include <Protocol/PciPlatform.h>
> +
> +///
> +/// Global ID for the EFI_PCI_PLATFORM_PROTOCOL2.
> +///
> +#define EFI_PCI_PLATFORM_PROTOCOL2_GUID \
> +  { \
> +    0x787b0367, 0xa945, 0x4d60, {0x8d, 0x34, 0xb9, 0xd1, 0x88, 0xd2,
> +0xd0, 0xb6} \
> +  }
> +
> +///
> +/// As per the present definition and specification of this protocol,
> +the major /// version is 1, and minor version is 1. Any driver
> +utilizing this protocol /// shall use these versions number to maintain
> +the backward compatibility as /// per its specification changes in future.
> +///
> +enum EfiPciPlatformProtocolVersion {
> +  EFI_PCI_PLATFORM_PROTOCOL_MAJOR_VERSION = 1,
> +  EFI_PCI_PLATFORM_PROTOCOL_MINOR_VERSION = 1 };
> +
> +///
> +/// Forward declaration for EFI_PCI_PLATFORM_PROTOCOL2.
> +///
> +typedef struct _EFI_PCI_PLATFORM_PROTOCOL2
> EFI_PCI_PLATFORM_PROTOCOL2;
> +
> +///
> +/// Following are the data types for EFI_PCI_PLATYFORM_EXTENDED_POLICY
> +/// each for the PCI standard feature and its corresponding bitmask ///
> +representing the valid combinations of PCI attributes ///
> +
> +///
> +/// This data type is to retrieve the PCI device platform policy for
> +the PCI- /// compliant feature Maximum Payload Size (MPS). Refer to PCI
> +Base Specification /// 4, (chapter 7.5.3.4) on how to translate the
> +below EFI encodings as per the /// PCI hardware terminology. If this
> +data member value is returned as 0 than /// there is no platform policy
> +to override, this feature would be enabled as /// per its PCI
> +specification based on the device capabilities. Below is it /// data
> +type and the macro definitions which the driver uses for interpreting /// the
> platform policy.
> +///
> +typedef UINT8 EFI_PCI_CONF_MAX_PAYLOAD_SIZE;
> +
> +#define EFI_PCI_CONF_MAX_PAYLOAD_SIZE_AUTO   0x00  //No request for
> override
> +#define EFI_PCI_CONF_MAX_PAYLOAD_SIZE_128B   0x01  //set to default 128B
> +#define EFI_PCI_CONF_MAX_PAYLOAD_SIZE_256B   0x02  //set to 256B if
> applicable
> +#define EFI_PCI_CONF_MAX_PAYLOAD_SIZE_512B   0x03  //set to 512B if
> applicable
> +#define EFI_PCI_CONF_MAX_PAYLOAD_SIZE_1024B  0x04  //set to 1024B if
> +applicable #define EFI_PCI_CONF_MAX_PAYLOAD_SIZE_2048B  0x05  //set to
> +2048B if applicable #define EFI_PCI_CONF_MAX_PAYLOAD_SIZE_4096B  0x06
> +//set to 4096B if applicable
> +
> +///
> +/// This data type is to retrieve the PCI device platform policy for
> +the PCI- /// compliant feature Maximum Read Request Size (MRRS). Refer
> +to PCI Base /// Specification 4, (chapter 7.5.3.4) on how to translate
> +the below EFI /// encodings as per the PCI hardware terminology. If
> +this data member value /// is returned as 0 than there is no platform
> +policy to override, this feature /// would be enabled as per its PCI specification
> based on the device capabilities.
> +/// Below is it data type and the macro definitions which the driver
> +uses for /// interpreting the platform policy.
> +///
> +typedef UINT8 EFI_PCI_CONF_MAX_READ_REQ_SIZE;
> +
> +#define EFI_PCI_CONF_MAX_READ_REQ_SIZE_AUTO  0x00  //No request for
> +override #define EFI_PCI_CONF_MAX_READ_REQ_SIZE_128B  0x01  //set to
> +default 128B #define EFI_PCI_CONF_MAX_READ_REQ_SIZE_256B  0x02  //set
> +to 256B if applicable #define EFI_PCI_CONF_MAX_READ_REQ_SIZE_512B  0x03
> +//set to 512B if applicable #define
> +EFI_PCI_CONF_MAX_READ_REQ_SIZE_1024B 0x04  //set to 1024B if applicable
> +#define EFI_PCI_CONF_MAX_READ_REQ_SIZE_2048B 0x05  //set to 2048B if
> +applicable #define EFI_PCI_CONF_MAX_READ_REQ_SIZE_4096B 0x06  //set to
> +4096B if applicable
> +
> +///
> +/// This data type is to retrieve the PCI device platform policy for
> +the PCI- /// compliant feature Extended Tags. Refer to PCI Base
> +Specification /// 4, (chapter 7.5.3.4) on how to translate the below
> +EFI encodings as per the /// PCI hardware terminology. If this data
> +member value is returned as 0 than /// there is no platform policy to
> +override, this feature would be enabled as /// per its PCI
> +specification based on the device capabilities. Below is it /// data
> +type and the macro definitions which the driver uses for interpreting /// the
> platform policy.
> +///
> +typedef UINT8 EFI_PCI_CONF_EXTENDED_TAG;
> +
> +#define EFI_PCI_CONF_EXTENDED_TAG_AUTO   0x00  //No request for
> override
> +#define EFI_PCI_CONF_EXTENDED_TAG_5BIT   0x01  //set to default 5-bit
> +#define EFI_PCI_CONF_EXTENDED_TAG_8BIT   0x02  //set to 8-bit if applicable
> +#define EFI_PCI_CONF_EXTENDED_TAG_10BIT  0x03  //set to 10-bit if
> +applicable
> +
> +///
> +/// This data type is to retrieve the PCI device platform policy for
> +the PCI- /// compliant feature PCIe link's Active State Power Mgmt
> +(ASPM). Refer to PCI Base /// Specification 4, (chapter 7.5.3.7) on how
> +to translate the below EFI /// encodings as per the PCI hardware
> +terminology. If this data member value /// is returned as 0 than there
> +is no platform policy to override, this feature /// would be enabled as per its
> PCI specification based on the device capabilities.
> +/// Below is it data type and the macro definitions which the driver
> +uses for /// interpreting the platform policy.
> +///
> +typedef UINT8 EFI_PCI_CONF_ASPM_SUPPORT;
> +
> +#define EFI_PCI_CONF_ASPM_AUTO           0x00  //No request for override
> +#define EFI_PCI_CONF_ASPM_DISABLE        0x01  //set to default disable state
> +#define EFI_PCI_CONF_ASPM_L0s_SUPPORT    0x02  //set to L0s state
> +#define EFI_PCI_CONF_ASPM_L1_SUPPORT     0x03  //set to L1 state
> +#define EFI_PCI_CONF_ASPM_L0S_L1_SUPPORT 0x04  //set to L0s and L1
> +state
> +
> +///
> +/// This data type is to retrieve the PCI device platform policy for
> +the PCI- /// compliant feature PCIe Device's Relax Ordering
> +enable/disable. Refer to PCI Base /// Specification 4, (chapter
> +7.5.3.4) on how to translate the below EFI /// encodings as per the PCI
> +hardware terminology. If this data member value /// is returned as 0
> +than there is no platform policy to override, this feature /// would be enabled
> as per its PCI specification based on the device capabilities.
> +/// Below is it data type and the macro definitions which the driver
> +uses for /// interpreting the platform policy.
> +///
> +typedef UINT8 EFI_PCI_CONF_RELAX_ORDER;
> +
> +#define EFI_PCI_CONF_RO_AUTO     0x00  //No request for override
> +#define EFI_PCI_CONF_RO_DISABLE  0x01  //set to default disable state
> +#define EFI_PCI_CONF_RO_ENABLE   0x02  //set to enable state
> +
> +///
> +/// This data type is to retrieve the PCI device platform policy for
> +the PCI- /// compliant feature PCIe Device's No-Snoop enable/disable.
> +Refer to PCI Base /// Specification 4, (chapter 7.5.3.4) on how to
> +translate the below EFI /// encodings as per the PCI hardware
> +terminology. If this data member value /// is returned as 0 than there
> +is no platform policy to override, this feature /// would be enabled as per its
> PCI specification based on the device capabilities.
> +/// Below is it data type and the macro definitions which the driver
> +uses for /// interpreting the platform policy.
> +///
> +typedef UINT8 EFI_PCI_CONF_NO_SNOOP;
> +
> +#define EFI_PCI_CONF_NS_AUTO     0x00  //No request for override
> +#define EFI_PCI_CONF_NS_DISABLE  0x01  //set to default disable state
> +#define EFI_PCI_CONF_NS_ENABLE   0x02  //set to enable state
> +
> +///
> +/// This data type is to retrieve the PCI device platform policy for
> +the PCI- /// compliant feature PCIe link's Clock configuration is common or
> discrete.
> +/// Refer to PCI Base Specification 4, (chapter 7.5.3.7) on how to
> +translate the /// below EFI encodings as per the PCI hardware
> +terminology. If this data member /// value is returned as 0 than there
> +is no platform policy to override, this /// feature would be enabled as
> +per its PCI specification based on the device /// capabilities. Below
> +is its data type and the macro definitions which the /// driver uses for
> interpreting the platform policy.
> +///
> +typedef UINT8 EFI_PCI_CONF_COMMON_CLOCK_CFG;
> +
> +#define EFI_PCI_CONF_CLK_CFG_AUTO    0x00   //No request for override
> +#define EFI_PCI_CONF_CLK_CFG_ASYNCH  0x01   //set to default
> asynchronous clock
> +#define EFI_PCI_CONF_CLK_CFG_COMMON  0x02   //set to common clock
> +
> +///
> +/// This data type is to retrieve the PCI device platform policy for
> +the PCI- /// compliant feature PCIe link's Extended Synch enable or disable.
> +/// Refer to PCI Base Specification 4, (chapter 7.5.3.7) on how to
> +translate the /// below EFI encodings as per the PCI hardware
> +terminology. If this data member /// value is returned as 0 than there
> +is no platform policy to override, this /// feature would be enabled as
> +per its PCI specification based on the device /// capabilities. Below
> +is its data type and the macro definitions which the /// driver uses for
> interpreting the platform policy.
> +///
> +typedef UINT8 EFI_PCI_CONF_EXTENDED_SYNCH;
> +
> +#define EFI_PCI_CONF_EXT_SYNCH_AUTO    0x00  //No request for override
> +#define EFI_PCI_CONF_EXT_SYNCH_DISABLE 0x01  //set to default disable
> +state #define EFI_PCI_CONF_EXT_SYNCH_ENABLE  0x02  //set to enable
> +state
> +
> +///
> +/// This data type is to retrieve the PCI device platform policy for
> +the PCI- /// compliant feature PCIe Device's AtomicOp Requester enable or
> disable.
> +/// Refer to PCI Base Specification 4, (chapter 7.5.3.16) on how to
> +translate the /// below EFI encodings as per the PCI hardware
> +terminology. If this data member /// value is returned as 0 than there
> +is no platform policy to override, this /// feature would be enabled as
> +per its PCI specification based on the device /// capabilities. Below
> +is its data type and the macro definitions which the /// driver uses for
> interpreting the platform policy.
> +///
> +typedef UINT8 EFI_PCI_CONF_ATOMIC_OP;
> +
> +#define EFI_PCI_CONF_ATOMIC_OP_AUTO    0x00  //No request for override
> +#define EFI_PCI_CONF_ATOMIC_OP_DISABLE 0x01  //set to default disable
> +state #define EFI_PCI_CONF_ATOMIC_OP_ENABLE  0x02  //set to enable
> +state
> +
> +///
> +/// This data type is to retrieve the PCI device platform policy for
> +the PCI- /// compliant feature PCIe Device's LTR Mechanism enable/disable.
> +/// Refer to PCI Base Specification 4, (chapter 7.5.3.16) on how to
> +translate the /// below EFI encodings as per the PCI hardware
> +terminology. If this data member /// value is returned as 0 than there
> +is no platform policy to override, this /// feature would be enabled as
> +per its PCI specification based on the device /// capabilities. Below
> +is its data type and the macro definitions which the /// driver uses for
> interpreting the platform policy.
> +///
> +typedef UINT8 EFI_PCI_CONF_LTR;
> +
> +#define EFI_PCI_CONF_LTR_AUTO    0x00  //No request for override
> +#define EFI_PCI_CONF_LTR_DISABLE 0x01  //set to default disable state
> +#define EFI_PCI_CONF_LTR_ENABLE  0x02  //set to enable state
> +
> +///
> +/// This data type is to retrieve the PCI device platform policy for
> +the PCI- /// compliant feature PCIe Device's Precision Time Measurement
> (PTM) enable/disable.
> +/// Refer to PCI Base Specification 4, (chapter 7.5.3.16) on how to
> +translate the /// below EFI encodings as per the PCI hardware
> +terminology. If this data member /// value is returned as 0 than there
> +is no platform policy to override, this /// feature would be enabled as
> +per its PCI specification based on the device /// capabilities. Below
> +is its data type and the macro definitions which the /// driver uses for
> interpreting the platform policy.
> +///
> +typedef UINT8 EFI_PCI_CONF_PTM;
> +
> +#define EFI_PCI_CONF_PTM_AUTO      0x00  //No request for override
> +#define EFI_PCI_CONF_PTM_DISABLE   0x01  //set to default disable state
> +#define EFI_PCI_CONF_PTM_ENABLE    0x02  //set to enable state only
> +#define EFI_PCI_CONF_PTM_ROOT_SEL  0x02  //set to root select & enable
> +
> +///
> +/// This data type is to retrieve the PCI device platform policy for
> +the PCI- /// compliant feature PCIe Device's Completion Timeout (CTO)
> +set to supported ranges /// or disable. Refer to PCI Base Specification
> +4, (chapter 7.5.3.16) on how to /// translate the below EFI encodings
> +as per the PCI hardware terminology. If this /// data member value is
> +returned as 0 than there is no platform policy to override, /// this
> +feature would be enabled as per its PCI specification based on the
> +device /// capabilities. Below is its data type and the macro definitions which
> the /// driver uses for interpreting the platform policy.
> +///
> +typedef UINT8 EFI_PCI_CONF_CTO_SUPPORT;
> +
> +#define EFI_PCI_CONF_CTO_AUTO        0x00  //No request for override
> +#define EFI_PCI_CONF_CTO_DEFAULT     0x01  //set to default range of 5us to
> 50ms if applicable
> +#define EFI_PCI_CONF_CTO_RANGE_A1    0x02  //set to range of 50us to
> 100us if applicable
> +#define EFI_PCI_CONF_CTO_RANGE_A2    0x03  //set to range of 1ms to 10ms
> if applicable
> +#define EFI_PCI_CONF_CTO_RANGE_B1    0x04  //set to range of 16ms to
> 55ms if applicable
> +#define EFI_PCI_CONF_CTO_RANGE_B2    0x05  //set to range of 65ms to
> 210ms if applicable
> +#define EFI_PCI_CONF_CTO_RANGE_C1    0x06  //set to range of 260ms to
> 900ms if applicable
> +#define EFI_PCI_CONF_CTO_RANGE_C2    0x07  //set to range of 1s to 3.5s if
> applicable
> +#define EFI_PCI_CONF_CTO_RANGE_D1    0x08  //set to range of 4s to 13s if
> applicable
> +#define EFI_PCI_CONF_CTO_RANGE_D2    0x09  //set to range of 17s to 64s if
> applicable
> +#define EFI_PCI_CONF_CTO_DET_DISABLE 0x10  //set to CTO detection
> +disable if applicable
> +
> +///
> +/// Reserves for future use
> +///
> +typedef UINT8 EFI_PCI_CONF_RESERVES;
> +
> +///
> +/// The EFI_PCI_PLATYFORM_EXTENDED_POLICY is altogether 128-byte size,
> +with each /// byte field representing one PCI standerd feature defined
> +in the PCI Express Base /// Specification 4.0, version 1.0.
> +///
> +typedef struct {
> +  EFI_PCI_CONF_MAX_PAYLOAD_SIZE  DeviceCtlMPS;
> +  EFI_PCI_CONF_MAX_READ_REQ_SIZE DeviceCtlMRRS;
> +  EFI_PCI_CONF_EXTENDED_TAG      DeviceCtlExtTag;
> +  EFI_PCI_CONF_RELAX_ORDER       DeviceCtlRelaxOrder;
> +  EFI_PCI_CONF_NO_SNOOP          DeviceCtlNoSnoop;
> +  EFI_PCI_CONF_ASPM_SUPPORT      LinkCtlASPMState;
> +  EFI_PCI_CONF_COMMON_CLOCK_CFG  LinkCtlCommonClkCfg;
> +  EFI_PCI_CONF_EXTENDED_SYNCH    LinkCtlExtSynch;
> +  EFI_PCI_CONF_ATOMIC_OP         DeviceCtl2AtomicOp;
> +  EFI_PCI_CONF_LTR               DeviceCtl2LTR;
> +  EFI_PCI_CONF_PTM               PTMControl;
> +  EFI_PCI_CONF_CTO_SUPPORT       CTOsupport;
> +  EFI_PCI_CONF_RESERVES          Reserves[116];
> +} EFI_PCI_PLATFORM_EXTENDED_POLICY;
> +
> +/**
> +  Retrieves the PCI device-specific platform policy regarding enumeration.
> +
> +  The PCI Bus driver and PCI Host Bridge Resource Allocation Protocol
> + drivers  can call this member function to retrieve the platform
> + policies specific to  PCI device, regarding the PCI enumeration.
> +
> +  The GetDevicePolicy() function retrieves the platform policy for a
> + particular  component regarding PCI enumeration. The PCI bus driver
> + and the PCI Host Bridge  Resource Allocation Protocol driver can call
> + this member function to retrieve  the policy.
> +  The existing GetPlatformPolicy() member function is used by the PCI
> + Bus driver  to program the legacy ranges, the data that is returned by
> + that member function  determines the supported attributes that are
> + returned by the
> +  EFI_PCI_IO_PROTOCOL.Attributes() function.
> +  The GetDevicePolicy() member function is meant to return data about
> + other PCI  compliant features which would be supported by the PCI Bus
> + driver in future;  like for example the MPS, MRRS, Extended Tag, ASPM,
> + etc. The details about  this PCI features can be obtained from the PCI
> + Base Specification 4.x. The  EFI encodings for these feature are
> + defined in the  EFI_PCI_PLATFORM_EXTENDED_POLICY, see the Related
> Definition section for this.
> +  This member function will use the associated EFI handle of the PCI IO
> + Protocol  to determine the physical PCI device within the chipset, to
> + return its  device-specific platform policies.
> +
> +  @param[in]  This          Pointer to the EFI_PCI_PLATFORM_PROTOCOL2
> instance.
> +  @param[in]  PciDevice     The associated PCI IO Protocol handle of the PCI
> +                            device. Type EFI_HANDLE is defined in
> +                            InstallProtocolInterface() in the UEFI 2.1
> +                            Specification  @param[in]  PciExtPolicy
> + The platform policy with respect to other PCI features
> +                            like, the MPS, MRRS, etc. Type
> EFI_PCI_PLATFORM_EXTENDED_POLICY
> +                            is defined in "Related Definitions" below.
> +
> +
> +  @retval EFI_SUCCESS            The function completed successfully, may returns
> +                                 platform policy data for the given PCI component
> +  @retval EFI_UNSUPPORTED        PCI component belongs to PCI topology but
> not
> +                                 part of chipset to provide the
> + platform policy  @retval EFI_INVALID_PARAMETER  If any of the input
> parameters are passed with
> +                                 invalid data
> +
> + **/
> +typedef
> +EFI_STATUS
> +(EFIAPI * EFI_PCI_PLATFORM_GET_DEVICE_POLICY) (
> +  IN   CONST EFI_PCI_PLATFORM_PROTOCOL2 *This,
> +  IN   EFI_HANDLE PciDevice,
> +  OUT  EFI_PCI_PLATFORM_EXTENDED_POLICY *PciExtPolicy );
> +
> +///
> +/// This protocol provides the interface between the PCI bus driver/PCI
> +Host /// Bridge Resource Allocation driver and a platform-specific
> +driver to describe /// the unique features of a platform.
> +///
> +struct _EFI_PCI_PLATFORM_PROTOCOL2 {
> +  ///
> +  /// The notification from the PCI bus enumerator to the platform that
> +it is about to
> +  /// enter a certain phase during the enumeration process.
> +  ///
> +  EFI_PCI_PLATFORM_PHASE_NOTIFY          PlatformNotify;
> +  ///
> +  /// The notification from the PCI bus enumerator to the platform for
> +each PCI
> +  /// controller at several predefined points during PCI controller initialization.
> +  ///
> +  EFI_PCI_PLATFORM_PREPROCESS_CONTROLLER PlatformPrepController;
> +  ///
> +  /// Retrieves the platform policy regarding enumeration.
> +  ///
> +  EFI_PCI_PLATFORM_GET_PLATFORM_POLICY   GetPlatformPolicy;
> +  ///
> +  /// Gets the PCI device's option ROM from a platform-specific location.
> +  ///
> +  EFI_PCI_PLATFORM_GET_PCI_ROM           GetPciRom;
> +  ///
> +  /// Retrieves the PCI device-specific platform policy regarding enumeration.
> +  ///
> +  EFI_PCI_PLATFORM_GET_DEVICE_POLICY     GetDevicePolicy;
> +  ///
> +  /// The major version of this PCI Platform Protocol
> +  ///
> +  UINT8                                  MajorVersion;
> +  ///
> +  /// The minor version of this PCI Platform Protocol
> +  ///
> +  UINT8                                  MinorVersion;
> +
> +};
> +
> +extern EFI_GUID   gEfiPciPlatformProtocol2Guid;
> +
> +#endif
> diff --git a/MdePkg/MdePkg.dec b/MdePkg/MdePkg.dec index
> b382efd578..670b448031 100644
> --- a/MdePkg/MdePkg.dec
> +++ b/MdePkg/MdePkg.dec
> @@ -1013,6 +1013,12 @@
>    ## Include/Protocol/PciOverride.h
>    gEfiPciOverrideProtocolGuid    = { 0xb5b35764, 0x460c, 0x4a06, {0x99, 0xfc,
> 0x77, 0xa1, 0x7c, 0x1b, 0x5c, 0xeb }}
> 
> +  ## Include/Protocol/PciPlatform2.h
> +  gEfiPciPlatformProtocol2Guid    = { 0x787b0367, 0xa945, 0x4d60, { 0x8d,
> 0x34, 0xb9, 0xd1, 0x88, 0xd2, 0xd0, 0xb6 }}
> +
> +  ## Include/Protocol/PciOverride2.h
> +  gEfiPciOverrideProtocol2Guid    = { 0xb9d5ea1, 0x66cb, 0x4546, { 0xb0, 0xbb,
> 0x5c, 0x6d, 0xae, 0xd9, 0x42, 0x47 }}
> +
>    ## Include/Protocol/PciEnumerationComplete.h
>    gEfiPciEnumerationCompleteProtocolGuid    = { 0x30cfe3e7, 0x3de1, 0x4586,
> {0xbe, 0x20, 0xde, 0xab, 0xa1, 0xb3, 0xb7, 0x93}}
> 
> --
> 2.21.0.windows.1
> 
> 
>