Re: [PATCH 4/4] DynamicTablesPkg: AcpiSsdtPcieLibArm: Add support for override protocol

["PierreGondois" <pierre.gondois@arm.com>]

Hello Jeff,
I think it would ideally be better to have the code adding/replacing the methods/objects
you noted inside the edk2/edk2-platfoms repositories. The methods/objects that you
want to replace seem to only concern:
-the objects available in the 'Device (PCIx)' node
-the _OSC method

If a library with the following two methods (extracted from SsdtPcieLibArm.inf) was created,
would it be sufficient for all the replacements you want to do ?
Like this we would have a generic implementation and specific ones.

EFI_STATUS
EFIAPI
GeneratePciDeviceInfo (
   IN      CONST CM_ARM_PCI_CONFIG_SPACE_INFO  *PciInfo,
   IN            UINT32                        Uid,
   IN  OUT       AML_OBJECT_NODE_HANDLE        PciNode
   )

EFI_STATUS
EFIAPI
AddOscMethod (
   IN  OUT   AML_OBJECT_NODE_HANDLE  PciNode
   )

Regards,
Pierre

On 7/1/22 17:52, Jeff Brasen wrote:
> Currently we do the following in this call.
> 
> Remove and replace the _OSC method on certain targets. I originally had this pass the template over but removed that when I added this more generic override support
> Add a _RST method to the root port device sub node
> Add a _DSD for device properties
> Conditionally add an entry for the device attached to the PCIe bus if we need to add properties or _RST methods. This will likely eventually move to another driver (which is the purpose of patch 2/4 in this series)
> 
> I figured trying to get the generator to handle that would be more difficult as these would be hard to generalize.
> 
> 
> Thanks,
> Jeff
> 
>> -----Original Message-----
>> From: Pierre Gondois <pierre.gondois@arm.com>
>> Sent: Friday, July 1, 2022 6:40 AM
>> To: Jeff Brasen <jbrasen@nvidia.com>; devel@edk2.groups.io
>> Cc: Sami.Mujawar@arm.com; Alexei.Fedorov@arm.com
>> Subject: Re: [PATCH 4/4] DynamicTablesPkg: AcpiSsdtPcieLibArm: Add
>> support for override protocol
>>
>> External email: Use caution opening links or attachments
>>
>>
>> Hello Jeff,
>> Is it possible to know what the UpdateTable() function would do ?
>> Maybe it would be possible to integrate the alternative implementation
>> without adding a new protocol.
>>
>> Regards,
>> Pierre
>>
>> On 6/30/22 17:48, Jeff Brasen wrote:
>>> Some platfoms may want to modify the ACPI table created.
>>> Add support for protocol that can provide an alternative implementation.
>>>
>>> Signed-off-by: Jeff Brasen <jbrasen@nvidia.com>
>>> ---
>>>    DynamicTablesPkg/DynamicTablesPkg.dec         |  3 +
>>>    .../Protocol/SsdtPcieOverrideProtocol.h       | 63 +++++++++++++++++++
>>>    .../AcpiSsdtPcieLibArm/SsdtPcieGenerator.c    | 31 ++++++++-
>>>    .../Arm/AcpiSsdtPcieLibArm/SsdtPcieLibArm.inf |  4 ++
>>>    4 files changed, 98 insertions(+), 3 deletions(-)
>>>    create mode 100644
>>> DynamicTablesPkg/Include/Protocol/SsdtPcieOverrideProtocol.h
>>>
>>> diff --git a/DynamicTablesPkg/DynamicTablesPkg.dec
>>> b/DynamicTablesPkg/DynamicTablesPkg.dec
>>> index a890a048be..bb66bdaf14 100644
>>> --- a/DynamicTablesPkg/DynamicTablesPkg.dec
>>> +++ b/DynamicTablesPkg/DynamicTablesPkg.dec
>>> @@ -43,6 +43,9 @@
>>>      # Dynamic Table Factory Protocol GUID
>>>      gEdkiiDynamicTableFactoryProtocolGuid = { 0x91d1e327, 0xfe5a,
>>> 0x49b8, { 0xab, 0x65, 0xe, 0xce, 0x2d, 0xdb, 0x45, 0xec } }
>>>
>>> +  # Protocol to override PCI SSDT table generation
>>> + gEdkiiDynamicTableSsdtPcieOverrideProtocolGuid = { 0x962e8b44,
>>> + 0x23b3, 0x41da, { 0x9f, 0x36, 0xca, 0xde, 0x68, 0x49, 0xfb, 0xf6 } }
>>> +
>>>    [PcdsFixedAtBuild]
>>>
>>>      # Maximum number of Custom ACPI Generators diff --git
>>> a/DynamicTablesPkg/Include/Protocol/SsdtPcieOverrideProtocol.h
>>> b/DynamicTablesPkg/Include/Protocol/SsdtPcieOverrideProtocol.h
>>> new file mode 100644
>>> index 0000000000..29568a0159
>>> --- /dev/null
>>> +++ b/DynamicTablesPkg/Include/Protocol/SsdtPcieOverrideProtocol.h
>>> @@ -0,0 +1,63 @@
>>> +/** @file
>>> +
>>> +  Copyright (c) 2022, NVIDIA CORPORATION. All rights reserved.
>>> +
>>> +  SPDX-License-Identifier: BSD-2-Clause-Patent
>>> +
>>> +**/
>>> +
>>> +#ifndef SSDT_PCIE_OVERRIDE_PROTOCOL_H_ #define
>>> +SSDT_PCIE_OVERRIDE_PROTOCOL_H_
>>> +
>>> +#include <ArmNameSpaceObjects.h>
>>> +#include <Library/AmlLib/AmlLib.h>
>>> +
>>> +/** This macro defines the SSDT PCI Override Protocol GUID.
>>> +
>>> +  GUID: {D85A4835-5A82-4894-AC02-706F43D5978E}
>>> +*/
>>> +#define EDKII_SSDT_PCI_OVERRIDE_PROTOCOL_GUID           \
>>> +  { 0x962e8b44, 0x23b3, 0x41da,                         \
>>> +    { 0x9f, 0x36, 0xca, 0xde, 0x68, 0x49, 0xfb, 0xf6 }  \
>>> +  };
>>> +
>>> +/**
>>> +  Forward declarations:
>>> +*/
>>> +typedef struct SsdtOverridePciProtocol
>>> +EDKII_SSDT_PCI_OVERRIDE_PROTOCOL;
>>> +
>>> +/** The UpdateTable function allows the override protocol to update the
>>> + *   PCIe SSDT table prior to being created.
>>> +
>>> +  @param [in]      This    Pointer to the SSDT PCI Override Protocol.
>>> +  @param [in]      PciInfo The PCIe configuration info for this node.
>>> +  @param [in]      Uid     UID that was selected for this PCIe node.
>>> +  @param [in, out] PciNode Pointer to the PCI node of this ACPI table.
>>> +
>>> +  @retval EFI_SUCCESS           Success.
>>> +  @retval EFI_INVALID_PARAMETER A parameter is invalid.
>>> +  @retval EFI_DEVICE_ERROR      Failed to update the table.
>>> +**/
>>> +typedef
>>> +EFI_STATUS
>>> +(EFIAPI *EDKII_SSDT_PCI_OVERRIDE_PROTOCOL_UPDATE_TABLE)(
>>> +  IN      CONST EDKII_SSDT_PCI_OVERRIDE_PROTOCOL  *CONST  This,
>>> +  IN      CONST CM_ARM_PCI_CONFIG_SPACE_INFO              *PciInfo,
>>> +  IN            UINT32                                    Uid,
>>> +  IN  OUT       AML_ROOT_NODE_HANDLE                      *PciNode
>>> +  );
>>> +
>>> +/** The EDKII_CONFIGURATION_MANAGER_PROTOCOL structure
>> describes the
>>> +    Configuration Manager Protocol interface.
>>> +*/
>>> +typedef struct SsdtOverridePciProtocol {
>>> +  /** The interface used to update the ACPI table for PCI.
>>> +  */
>>> +  EDKII_SSDT_PCI_OVERRIDE_PROTOCOL_UPDATE_TABLE    UpdateTable;
>>> +} EDKII_SSDT_PCI_OVERRIDE_PROTOCOL;
>>> +
>>> +/** The SSDT PCI Override Protocol GUID.
>>> +*/
>>> +extern EFI_GUID  gEdkiiDynamicTableSsdtPcieOverrideProtocolGuid;
>>> +
>>> +#endif // SSDT_PCIE_OVERRIDE_PROTOCOL_H_
>>> diff --git
>>>
>> a/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtPcieLibArm/SsdtPcieGenera
>> t
>>> or.c
>>>
>> b/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtPcieLibArm/SsdtPcieGenera
>> t
>>> or.c
>>> index c5b23d91d0..d5982c24ff 100644
>>> ---
>>>
>> a/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtPcieLibArm/SsdtPcieGenera
>> t
>>> or.c
>>> +++
>> b/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtPcieLibArm/SsdtPcieGen
>>> +++ erator.c
>>> @@ -20,6 +20,7 @@
>>>    #include <Library/BaseMemoryLib.h>
>>>    #include <Library/DebugLib.h>
>>>    #include <Library/MemoryAllocationLib.h>
>>> +#include <Library/UefiBootServicesTableLib.h>
>>>    #include <Protocol/AcpiTable.h>
>>>
>>>    // Module specific include files.
>>> @@ -30,6 +31,7 @@
>>>    #include <Library/TableHelperLib.h>
>>>    #include <Library/AmlLib/AmlLib.h>
>>>    #include <Protocol/ConfigurationManagerProtocol.h>
>>> +#include <Protocol/SsdtPcieOverrideProtocol.h>
>>>
>>>    #include "SsdtPcieGenerator.h"
>>>
>>> @@ -798,9 +800,10 @@ GeneratePciDevice (
>>>    {
>>>      EFI_STATUS  Status;
>>>
>>> -  CHAR8                   AslName[AML_NAME_SEG_SIZE + 1];
>>> -  AML_OBJECT_NODE_HANDLE  ScopeNode;
>>> -  AML_OBJECT_NODE_HANDLE  PciNode;
>>> +  CHAR8                             AslName[AML_NAME_SEG_SIZE + 1];
>>> +  AML_OBJECT_NODE_HANDLE            ScopeNode;
>>> +  AML_OBJECT_NODE_HANDLE            PciNode;
>>> +  EDKII_SSDT_PCI_OVERRIDE_PROTOCOL  *OverrideProtocol;
>>>
>>>      ASSERT (Generator != NULL);
>>>      ASSERT (CfgMgrProtocol != NULL);
>>> @@ -860,6 +863,28 @@ GeneratePciDevice (
>>>
>>>      // Add the template _OSC method.
>>>      Status = AddOscMethod (PciNode);
>>> +  if (EFI_ERROR (Status)) {
>>> +    ASSERT (0);
>>> +    return Status;
>>> +  }
>>> +
>>> +  Status = gBS->LocateProtocol (
>>> +                  &gEdkiiDynamicTableSsdtPcieOverrideProtocolGuid,
>>> +                  NULL,
>>> +                  (VOID **)&OverrideProtocol
>>> +                  );
>>> +  if (!EFI_ERROR (Status)) {
>>> +    Status = OverrideProtocol->UpdateTable (
>>> +                                 OverrideProtocol,
>>> +                                 PciInfo,
>>> +                                 Uid,
>>> +                                 PciNode
>>> +                                 );
>>> +  } else {
>>> +    // Not an error if override protocol is not found
>>> +    Status = EFI_SUCCESS;
>>> +  }
>>> +
>>>      ASSERT_EFI_ERROR (Status);
>>>      return Status;
>>>    }
>>> diff --git
>>>
>> a/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtPcieLibArm/SsdtPcieLibArm.
>>> inf
>>>
>> b/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtPcieLibArm/SsdtPcieLibArm.
>>> inf
>>> index 431e32a777..8e916f15e9 100644
>>> ---
>>>
>> a/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtPcieLibArm/SsdtPcieLibArm.
>>> inf
>>> +++
>> b/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtPcieLibArm/SsdtPcieLib
>>> +++ Arm.inf
>>> @@ -30,6 +30,10 @@
>>>      AcpiHelperLib
>>>      AmlLib
>>>      BaseLib
>>> +  UefiBootServicesTableLib
>>>
>>>    [Pcd]
>>>      gEdkiiDynamicTablesPkgTokenSpaceGuid.PcdPciUseSegmentAsUid
>>> +
>>> +[Protocols]
>>> +  gEdkiiDynamicTableSsdtPcieOverrideProtocolGuid