Re: [edk2-devel] [PATCH v2] MdeModulePkg: Enable/Disable S3BootScript dynamically.

["Laszlo Ersek" <lersek@redhat.com>]

On 09/25/19 11:21, Chiu, Chasel wrote:
> REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2212
> 
> In binary model the same binary may have to support both
> S3 enabled and disabled scenarios, however not all DXE
> drivers linking PiDxeS3BootScriptLib can return error to
> invoke library DESTRUCTOR for releasing resource.

Thanks, this sounds better. More comments:

> To support this usage model below PCD is used to skip
> S3BootScript functions when PCD set to FALSE:
>   gEfiMdeModulePkgTokenSpaceGuid.PcdAcpiS3Enable
> 
> Test: Verified on internal platform and S3BootScript
>       functions can be skipped by PCD during boot time.
> 
> Cc: Hao A Wu <hao.a.wu@intel.com>
> Cc: Eric Dong <eric.dong@intel.com>
> Cc: Nate DeSimone <nathaniel.l.desimone@intel.com>
> Cc: Liming Gao <liming.gao@intel.com>
> Cc: Laszlo Ersek <lersek@redhat.com>
> Signed-off-by: Chasel Chiu <chasel.chiu@intel.com>
> ---
>  MdeModulePkg/Library/PiDxeS3BootScriptLib/BootScriptSave.c       | 13 ++++++++++++-
>  MdeModulePkg/Library/PiDxeS3BootScriptLib/DxeS3BootScriptLib.inf |  4 +++-
>  2 files changed, 15 insertions(+), 2 deletions(-)
> 
> diff --git a/MdeModulePkg/Library/PiDxeS3BootScriptLib/BootScriptSave.c b/MdeModulePkg/Library/PiDxeS3BootScriptLib/BootScriptSave.c
> index c116727531..c5353119f7 100644
> --- a/MdeModulePkg/Library/PiDxeS3BootScriptLib/BootScriptSave.c
> +++ b/MdeModulePkg/Library/PiDxeS3BootScriptLib/BootScriptSave.c
> @@ -1,7 +1,7 @@
>  /** @file
>    Save the S3 data to S3 boot script.
>  
> -  Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.<BR>
> +  Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.<BR>
>  
>    SPDX-License-Identifier: BSD-2-Clause-Patent
>  
> @@ -124,6 +124,7 @@ VOID                             *mRegistrationSmmReadyToLock = NULL;
>  BOOLEAN                          mS3BootScriptTableAllocated = FALSE;
>  BOOLEAN                          mS3BootScriptTableSmmAllocated = FALSE;
>  EFI_SMM_SYSTEM_TABLE2            *mBootScriptSmst = NULL;
> +BOOLEAN                          mAcpiS3Enable = TRUE;
>  
>  /**
>    This is an internal function to add a terminate node the entry, recalculate the table
> @@ -436,6 +437,11 @@ S3BootScriptLibInitialize (
>    BOOLEAN                        InSmm;
>    EFI_PHYSICAL_ADDRESS           Buffer;
>  
> +  if (!PcdGetBool (PcdAcpiS3Enable)) {
> +    mAcpiS3Enable = FALSE;
> +    return RETURN_SUCCESS;
> +  }
> +
>    S3TablePtr = (SCRIPT_TABLE_PRIVATE_DATA*)(UINTN)PcdGet64(PcdS3BootScriptTablePrivateDataPtr);
>    //
>    // The Boot script private data is not be initialized. create it

(1) I think that, for future maintenance, it would help if we added a
similar check (on mAcpiS3Enable) to S3BootScriptLibDeinitialize() as well.

I understand that, right now, if the constructor is short-circuited,
then the destructor will end up doing nothing. But I think it would make
maintenance easier if the destructor were short-circuited explicitly as
well.


> @@ -810,6 +816,11 @@ S3BootScriptGetEntryAddAddress (
>  {
>    UINT8*                         NewEntryPtr;
>  
> +  if (!mAcpiS3Enable) {
> +    DEBUG ((DEBUG_INFO, "Skip S3BootScript because ACPI S3 disabled.\n"));
> +    return NULL;
> +  }
> +
>    if (mS3BootScriptTablePtr->SmmLocked) {
>      //
>      // We need check InSmm, because after SmmReadyToLock, only SMM driver is allowed to write boot script.

(2) I would like to see the debug message updated:

(2a) please log, as part of the message, with "%a", the
"gEfiCallerBaseName" variable. A library instance can be linked into
multiple modules, and knowing the module name is useful.

(2b) I think we should add the debug message to the constructor function
instead. Please see the message that we already have in the destructor.

Mainly, a DEBUG_INFO message is too loud for a utility function that may
be called several times. So, if we keep the message at DEBUG_INFO, it
should be moved into the constructor. Conversely, if you want to keep
the message in S3BootScriptGetEntryAddAddress(), then it should be
downgraded to DEBUG_VERBOSE.


> diff --git a/MdeModulePkg/Library/PiDxeS3BootScriptLib/DxeS3BootScriptLib.inf b/MdeModulePkg/Library/PiDxeS3BootScriptLib/DxeS3BootScriptLib.inf
> index 517ea69568..fa139b03ff 100644
> --- a/MdeModulePkg/Library/PiDxeS3BootScriptLib/DxeS3BootScriptLib.inf
> +++ b/MdeModulePkg/Library/PiDxeS3BootScriptLib/DxeS3BootScriptLib.inf
> @@ -1,7 +1,7 @@
>  ## @file
>  # DXE S3 boot script Library.
>  #
> -# Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
> +# Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.<BR>
>  #
>  # SPDX-License-Identifier: BSD-2-Clause-Patent
>  #
> @@ -65,4 +65,6 @@
>    ## SOMETIMES_PRODUCES
>    gEfiMdeModulePkgTokenSpaceGuid.PcdS3BootScriptTablePrivateSmmDataPtr
>    gEfiMdeModulePkgTokenSpaceGuid.PcdS3BootScriptRuntimeTableReservePageNumber   ## CONSUMES
> +  gEfiMdeModulePkgTokenSpaceGuid.PcdAcpiS3Enable                                ## CONSUMES
> +

(3) Please do not add the superfluous empty line.

Thanks
Laszlo