Re: [PATCH v2 05/12] ArmPkg: introduce EDKII Platform Has ACPI Protocol, and plug-in library

[Laszlo Ersek <lersek@redhat.com>]

Mike,

considering time zones and to expedite progress on this series, can you
please offer an opinion whether you would be okay with this one patch
(see full context below) if I posted it for MdeModulePkg, rather than
for ArmPkg?

MdeModulePkg was suggested by Leif.

Thanks!
Laszlo

On 03/17/17 21:47, Laszlo Ersek wrote:
> The presence of this protocol in the DXE protocol database implies that
> the platform provides the operating system with an ACPI-based hardware
> description. This is not necessarily mutually exclusive with a Device
> Tree-based hardware description. A platform driver is supposed to produce
> a single instance of the protocol (with NULL contents), if appropriate.
> 
> The decision to produce the protocol is platform specific; for example, it
> could depend on an HII checkbox / underlying non-volatile UEFI variable.
> 
> The protocol is meant to be consumed by
> "MdeModulePkg/Universal/Acpi/AcpiTableDxe", through the
> PlatformHasAcpiLib plug-in. By linking this library into AcpiTableDxe via
> NULL resolution in the platform DSC, the platform makes
> EFI_ACPI_TABLE_PROTOCOL and (if enabled) EFI_ACPI_SDT_PROTOCOL dependent
> on the above dynamic decision.
> 
> In turn, other (platform and universal) DXE drivers that produce ACPI
> tables will wait for EFI_ACPI_TABLE_PROTOCOL / EFI_ACPI_SDT_PROTOCOL, via
> DEPEX, protocol notify, or a simple gBS->LocateProtocol() in a "late
> enough" callback (such as Ready To Boot).
> 
> Because this protocol is not standard, it is prefixed with EDKII / Edkii,
> as seen elsewhere in MdeModulePkg and SecurityPkg, for example. (ARM / Arm
> doesn't look future-proof enough; future UEFI platforms could face the
> same issue.) In addition, an effort is made to avoid the phrase
> "AcpiPlatform", as that belongs to drivers / libraries that produce
> platform specific ACPI content (as opposed to deciding whether the entire
> firmware will have access to EFI_ACPI_TABLE_PROTOCOL).
> 
> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> Cc: Leif Lindholm <leif.lindholm@linaro.org>
> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Laszlo Ersek <lersek@redhat.com>
> ---
>  ArmPkg/ArmPkg.dec                                        |  4 ++
>  ArmPkg/Library/PlatformHasAcpiLib/PlatformHasAcpiLib.inf | 40 ++++++++++++++++++++
>  ArmPkg/Include/Protocol/PlatformHasAcpi.h                | 34 +++++++++++++++++
>  ArmPkg/Library/PlatformHasAcpiLib/PlatformHasAcpiLib.c   | 36 ++++++++++++++++++
>  4 files changed, 114 insertions(+)
> 
> diff --git a/ArmPkg/ArmPkg.dec b/ArmPkg/ArmPkg.dec
> index c4b4da2f95bb..0e49360a386a 100644
> --- a/ArmPkg/ArmPkg.dec
> +++ b/ArmPkg/ArmPkg.dec
> @@ -52,6 +52,10 @@ [Ppis]
>    ## Include/Ppi/ArmMpCoreInfo.h
>    gArmMpCoreInfoPpiGuid = { 0x6847cc74, 0xe9ec, 0x4f8f, {0xa2, 0x9d, 0xab, 0x44, 0xe7, 0x54, 0xa8, 0xfc} }
>  
> +[Protocols]
> +  ## Include/Protocol/PlatformHasAcpi.h
> +  gEdkiiPlatformHasAcpiProtocolGuid =       { 0xf0966b41, 0xc23f, 0x41b9, { 0x96, 0x04, 0x0f, 0xf7, 0xe1, 0x11, 0x96, 0x5a } }
> +
>  [PcdsFeatureFlag.common]
>    gArmTokenSpaceGuid.PcdCpuDxeProduceDebugSupport|FALSE|BOOLEAN|0x00000001
>  
> diff --git a/ArmPkg/Library/PlatformHasAcpiLib/PlatformHasAcpiLib.inf b/ArmPkg/Library/PlatformHasAcpiLib/PlatformHasAcpiLib.inf
> new file mode 100644
> index 000000000000..c83da4d8e98a
> --- /dev/null
> +++ b/ArmPkg/Library/PlatformHasAcpiLib/PlatformHasAcpiLib.inf
> @@ -0,0 +1,40 @@
> +## @file
> +# A hook-in library for MdeModulePkg/Universal/Acpi/AcpiTableDxe.
> +#
> +# Plugging this library instance into AcpiTableDxe makes
> +# EFI_ACPI_TABLE_PROTOCOL and (if enabled) EFI_ACPI_SDT_PROTOCOL depend on the
> +# platform's dynamic decision whether to expose an ACPI-based hardware
> +# description to the operating system.
> +#
> +# Universal and platform specific DXE drivers that produce ACPI tables depend
> +# on EFI_ACPI_TABLE_PROTOCOL / EFI_ACPI_SDT_PROTOCOL in turn.
> +#
> +# Copyright (C) 2017, Red Hat, Inc.
> +#
> +# 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.
> +##
> +
> +[Defines]
> +  INF_VERSION                    = 1.25
> +  BASE_NAME                      = PlatformHasAcpiLib
> +  FILE_GUID                      = 29beb028-0958-447b-be0a-12229235d77d
> +  MODULE_TYPE                    = BASE
> +  VERSION_STRING                 = 1.0
> +  LIBRARY_CLASS                  = PlatformHasAcpiLib|DXE_DRIVER
> +  CONSTRUCTOR                    = PlatformHasAcpiInitialize
> +
> +[Sources]
> +  PlatformHasAcpiLib.c
> +
> +[Packages]
> +  ArmPkg/ArmPkg.dec
> +  MdePkg/MdePkg.dec
> +
> +[Depex]
> +  gEdkiiPlatformHasAcpiProtocolGuid
> diff --git a/ArmPkg/Include/Protocol/PlatformHasAcpi.h b/ArmPkg/Include/Protocol/PlatformHasAcpi.h
> new file mode 100644
> index 000000000000..3cd0cfe4515d
> --- /dev/null
> +++ b/ArmPkg/Include/Protocol/PlatformHasAcpi.h
> @@ -0,0 +1,34 @@
> +/** @file
> +  EDKII Platform Has ACPI Protocol
> +
> +  The presence of this protocol in the DXE protocol database implies that the
> +  platform provides the operating system with an ACPI-based hardware
> +  description. Note that this is not necessarily mutually exclusive with a
> +  Device Tree-based hardware description. A platform driver is supposed to
> +  produce a single instance of the protocol (with NULL contents), if
> +  appropriate.
> +
> +  Copyright (C) 2017, Red Hat, Inc.
> +
> +  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 __EDKII_PLATFORM_HAS_ACPI_PROTOCOL_H__
> +#define __EDKII_PLATFORM_HAS_ACPI_PROTOCOL_H__
> +
> +#define EDKII_PLATFORM_HAS_ACPI_PROTOCOL_GUID \
> +  { \
> +    0xf0966b41, 0xc23f, 0x41b9, \
> +    { 0x96, 0x04, 0x0f, 0xf7, 0xe1, 0x11, 0x96, 0x5a } \
> +  }
> +
> +extern EFI_GUID gEdkiiPlatformHasAcpiProtocolGuid;
> +
> +#endif
> diff --git a/ArmPkg/Library/PlatformHasAcpiLib/PlatformHasAcpiLib.c b/ArmPkg/Library/PlatformHasAcpiLib/PlatformHasAcpiLib.c
> new file mode 100644
> index 000000000000..79072da21c2b
> --- /dev/null
> +++ b/ArmPkg/Library/PlatformHasAcpiLib/PlatformHasAcpiLib.c
> @@ -0,0 +1,36 @@
> +/** @file
> +  A hook-in library for MdeModulePkg/Universal/Acpi/AcpiTableDxe.
> +
> +  Plugging this library instance into AcpiTableDxe makes
> +  EFI_ACPI_TABLE_PROTOCOL and (if enabled) EFI_ACPI_SDT_PROTOCOL depend on the
> +  platform's dynamic decision whether to expose an ACPI-based hardware
> +  description to the operating system.
> +
> +  Universal and platform specific DXE drivers that produce ACPI tables depend
> +  on EFI_ACPI_TABLE_PROTOCOL / EFI_ACPI_SDT_PROTOCOL in turn.
> +
> +  Copyright (C) 2017, Red Hat, Inc.
> +
> +  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.
> +**/
> +
> +#include <Base.h>
> +
> +RETURN_STATUS
> +EFIAPI
> +PlatformHasAcpiInitialize (
> +  VOID
> +  )
> +{
> +  //
> +  // Do nothing, just imbue AcpiTableDxe with an
> +  // EDKII_PLATFORM_HAS_ACPI_PROTOCOL dependency.
> +  //
> +  return RETURN_SUCCESS;
> +}
>