Re: [PATCH 1/2] Platform/ARM/Sgi: Install a Platform ID HOB

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

On 15 June 2018 at 08:16, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote:
> Hello Chandni,
>
> On 15 June 2018 at 07:55, Chandni Cherukuri <chandni.cherukuri@arm.com> wrote:
>> On SGI platforms, the trusted firmware executes prior to
>> the SEC phase. It supplies to the SEC phase a pointer to
>> a fdt, that contains platform specific information such as
>> part number and config number of the SGI platform. The
>> platform code that executes during the SEC phase creates a
>> PPI that allows access to other PEIMs to obtain a copy of the
>> fdt pointer.
>>
>> Further, during the PEI phase, a Platform ID PEIM installs a
>> Platform ID HOB. The Platform ID HOB can be used by DXE
>> drivers to identify the platform it is executing on.
>>
>> Contributed-under: TianoCore Contribution Agreement 1.1
>> Signed-off-by: Chandni Cherukuri <chandni.cherukuri@arm.com>
>> ---
>>  .../SgiPkg/Library/PlatformLib/AArch64/Helper.S    |  15 ++-
>>  .../ARM/SgiPkg/Library/PlatformLib/PlatformLib.c   |  10 ++
>>  .../ARM/SgiPkg/Library/PlatformLib/PlatformLib.inf |   3 +
>>  .../Library/SgiPlatformPeiLib/SgiPlatformPeiLib.c  | 108 +++++++++++++++++++++
>>  .../SgiPlatformPeiLib/SgiPlatformPeiLib.inf        |  40 ++++++++
>>  Platform/ARM/SgiPkg/SgiPlatform.dec                |   5 +
>>  6 files changed, 177 insertions(+), 4 deletions(-)
>>  create mode 100644 Platform/ARM/SgiPkg/Library/SgiPlatformPeiLib/SgiPlatformPeiLib.c
>>  create mode 100644 Platform/ARM/SgiPkg/Library/SgiPlatformPeiLib/SgiPlatformPeiLib.inf
>>
>
> Please use '--stat=250 --stat-graph-width=20' when using git
> format-patch so that we get to see the entire path names in the
> diffstat
>
>> diff --git a/Platform/ARM/SgiPkg/Library/PlatformLib/AArch64/Helper.S b/Platform/ARM/SgiPkg/Library/PlatformLib/AArch64/Helper.S
>> index dab6c77..80b93ea 100644
>> --- a/Platform/ARM/SgiPkg/Library/PlatformLib/AArch64/Helper.S
>> +++ b/Platform/ARM/SgiPkg/Library/PlatformLib/AArch64/Helper.S
>> @@ -22,15 +22,22 @@ GCC_ASM_EXPORT(ArmPlatformPeiBootAction)
>>  GCC_ASM_EXPORT(ArmPlatformGetCorePosition)
>>  GCC_ASM_EXPORT(ArmPlatformGetPrimaryCoreMpId)
>>  GCC_ASM_EXPORT(ArmPlatformIsPrimaryCore)
>> +GCC_ASM_EXPORT(HwConfigDtBlob)
>> +
>> +HwConfigDtBlob: .long 0
>>
>
> Please move this definition to PlatformLib.c
>
>>  //
>>  // First platform specific function to be called in the PEI phase
>>  //
>> -// This function is actually the first function called by the PrePi
>> -// or PrePeiCore modules. It allows to retrieve arguments passed to
>> -// the UEFI firmware through the CPU registers.
>> -//
>> +// The trusted firmware passed the hw config DT blob in x1 register.
>> +// Keep a copy of it in a global variable.
>> +//VOID
>> +//ArmPlatformPeiBootAction (
>> +//  VOID
>> +//  );
>>  ASM_PFX(ArmPlatformPeiBootAction):
>> +  ldr  x10, =HwConfigDtBlob
>
> Please use adr to take the address of HwConfigDtBlob
>
>> +  str  x1, [x10]
>>    ret
>>
>>  //UINTN
>> diff --git a/Platform/ARM/SgiPkg/Library/PlatformLib/PlatformLib.c b/Platform/ARM/SgiPkg/Library/PlatformLib/PlatformLib.c
>> index ea3201a..54860e0 100644
>> --- a/Platform/ARM/SgiPkg/Library/PlatformLib/PlatformLib.c
>> +++ b/Platform/ARM/SgiPkg/Library/PlatformLib/PlatformLib.c
>> @@ -15,6 +15,10 @@
>>  #include <Library/ArmPlatformLib.h>
>>  #include <Library/BaseLib.h>
>>  #include <Ppi/ArmMpCoreInfo.h>
>> +#include <SgiPlatform.h>
>> +
>> +extern UINT64 HwConfigDtBlob;
>> +STATIC SGI_HW_CONFIG_INFO_PPI mHwConfigDtInfoPpi;
>>
>
> Where is this PPI declared? A PPI is like a protocol, it has its own
> declaration in a header file under Include/Ppi in the package
>
>>  STATIC ARM_CORE_INFO mCoreInfoTable[] = {
>>    {
>> @@ -36,6 +40,7 @@ ArmPlatformInitialize (
>>    IN  UINTN                     MpId
>>    )
>>  {
>> +  mHwConfigDtInfoPpi.HwConfigDtAddr = &HwConfigDtBlob;
>>    return RETURN_SUCCESS;
>>  }
>>
>> @@ -59,6 +64,11 @@ EFI_PEI_PPI_DESCRIPTOR gPlatformPpiTable[] = {
>>      EFI_PEI_PPI_DESCRIPTOR_PPI,
>>      &gArmMpCoreInfoPpiGuid,
>>      &mMpCoreInfoPpi
>> +  },
>> +  {
>> +    EFI_PEI_PPI_DESCRIPTOR_PPI,
>> +    &gHwConfigDtInfoPpiGuid,
>> +    &mHwConfigDtInfoPpi
>>    }
>>  };
>>
>> diff --git a/Platform/ARM/SgiPkg/Library/PlatformLib/PlatformLib.inf b/Platform/ARM/SgiPkg/Library/PlatformLib/PlatformLib.inf
>> index 42e14d5..5d4bf72 100644
>> --- a/Platform/ARM/SgiPkg/Library/PlatformLib/PlatformLib.inf
>> +++ b/Platform/ARM/SgiPkg/Library/PlatformLib/PlatformLib.inf
>> @@ -61,7 +61,10 @@
>>    gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress
>>
>>  [Guids]
>> +  gArmSgiPlatformIdDescriptorGuid
>>    gEfiHobListGuid          ## CONSUMES  ## SystemTable
>> +  gFdtTableGuid
>>
>>  [Ppis]
>>    gArmMpCoreInfoPpiGuid
>> +  gHwConfigDtInfoPpiGuid
>> diff --git a/Platform/ARM/SgiPkg/Library/SgiPlatformPeiLib/SgiPlatformPeiLib.c b/Platform/ARM/SgiPkg/Library/SgiPlatformPeiLib/SgiPlatformPeiLib.c
>> new file mode 100644
>> index 0000000..f6446e6
>> --- /dev/null
>> +++ b/Platform/ARM/SgiPkg/Library/SgiPlatformPeiLib/SgiPlatformPeiLib.c
>> @@ -0,0 +1,108 @@
>> +/** @file
>> +*
>> +*  Copyright (c) 2018, ARM Limited. All rights reserved.
>> +*
>> +*  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 <Library/DebugLib.h>
>> +#include <Library/HobLib.h>
>> +#include <Library/PeimEntryPoint.h>
>> +#include <Library/PeiServicesLib.h>
>> +#include <libfdt.h>
>> +#include <SgiPlatform.h>
>> +
>> +/**
>> +
>> +  This function returns the Platform ID of the platform
>> +
>> +  This functions locates the HwConfig PPI and gets the base address of HW CONFIG
>> +  DT from which the platform ID is obtained using FDT helper functions
>> +
>> +  @return returns the platform ID on success else returns 0 on error
>> +
>> +**/
>> +
>> +STATIC
>> +UINT32
>> +GetSgiPlatformId (
>> + VOID
>> +)
>> +{
>> +  CONST UINT32                  *Property;
>> +  INT32                         Offset;
>> +  CONST VOID                    *HwCfgDtBlob;
>> +  SGI_HW_CONFIG_INFO_PPI        *HwConfigInfoPpi;
>> +  EFI_STATUS                    Status;
>> +
>> +  Status = PeiServicesLocatePpi (&gHwConfigDtInfoPpiGuid, 0, NULL, (VOID**)&HwConfigInfoPpi);
>
> Please check all your patches for overly long lines. 80 columns is that maximum
>
>> +  if (EFI_ERROR (Status)) {
>> +    DEBUG ((DEBUG_ERROR, "PeiServicesLocatePpi failed with error %r\n", Status));
>> +    return 0;
>> +  }
>> +
>> +  HwCfgDtBlob = (VOID *)(*(HwConfigInfoPpi->HwConfigDtAddr));
>> +  if (fdt_check_header (HwCfgDtBlob) != 0 ) {
>> +    DEBUG ((DEBUG_ERROR, "Invalid DTB file %p passed as HW_CONFIG\n", HwCfgDtBlob));
>> +    return 0;
>> +  }
>> +
>> +  Offset = fdt_subnode_offset (HwCfgDtBlob, 0, "system-id");
>> +  if (Offset == -FDT_ERR_NOTFOUND) {
>> +    DEBUG ((DEBUG_ERROR, "Invalid DTB : system-id node not found\n"));
>> +    return 0;
>> +  }
>> +
>> +  Property = fdt_getprop (HwCfgDtBlob, Offset, "platform-id", NULL);
>> +  if (Property == NULL) {
>> +    DEBUG ((DEBUG_ERROR, "Platform Id is NULL\n"));
>> +    return 0;
>> +  }
>> +
>> +  return fdt32_to_cpu (*Property);
>> +}
>> +
>> +/**
>> +
>> + This function creates a Platform ID HOB and assigns PlatformId as the
>> + HobData
>> +
>> + @return asserts on error and returns EFI_INVALID_PARAMETER. On success
>> + returns EFI_SUCCESS
>> +
>> +**/
>> +EFI_STATUS
>> +EFIAPI
>> +SgiPlatformIdPeim (
>> + IN       EFI_PEI_FILE_HANDLE  FileHandle,
>> + IN CONST EFI_PEI_SERVICES     **PeiServices
>> +)
>> +{
>> +  SGI_PLATFORM_DESCRIPTOR       *HobData;
>> +
>> +  //Create platform descriptor HOB
>> +  HobData = (SGI_PLATFORM_DESCRIPTOR *)BuildGuidHob (&gArmSgiPlatformIdDescriptorGuid,
>> +            sizeof (SGI_PLATFORM_DESCRIPTOR));
>> +
>> +  //Get the platform id from the platform specific hw_config device tree
>> +  if (HobData != NULL) {
>
> Please invert the sense of this conditional, and return
> EFI_OUT_OF_RESOURCES if HobData is NULL
>
>> +    HobData->PlatformId = GetSgiPlatformId ();
>> +    if (HobData->PlatformId == 0) {
>> +      ASSERT (FALSE);
>> +      return EFI_INVALID_PARAMETER;
>> +    }
>> +  } else {
>
> After you have inverted the if() condition, you can drop the else as well
>
>> +    DEBUG ((DEBUG_ERROR, "Platform HoB is NULL\n"));
>> +    ASSERT (FALSE);
>> +    return EFI_INVALID_PARAMETER;
>> +  }
>> +
>> +  return EFI_SUCCESS;
>> +}
>> diff --git a/Platform/ARM/SgiPkg/Library/SgiPlatformPeiLib/SgiPlatformPeiLib.inf b/Platform/ARM/SgiPkg/Library/SgiPlatformPeiLib/SgiPlatformPeiLib.inf
>> new file mode 100644
>> index 0000000..502d6ac
>> --- /dev/null
>> +++ b/Platform/ARM/SgiPkg/Library/SgiPlatformPeiLib/SgiPlatformPeiLib.inf
>> @@ -0,0 +1,40 @@
>> +#
>> +#  Copyright (c) 2018, ARM Limited. All rights reserved.
>> +#
>> +#  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                    = 0x0001001A
>> +  BASE_NAME                      = SgiPlatformIdPeiLib

I forgot: this is a module not a library. So it should be called
SgiPlatformIdPei or SgiPlatformIdPeim not ...Lib

>> +  FILE_GUID                      = a9936f3e-6a1b-11e8-8ce0-fffe69b86863
>> +  MODULE_TYPE                    = PEIM
>> +  VERSION_STRING                 = 1.0
>> +  ENTRY_POINT                    = SgiPlatformIdPeim
>> +
>> +[Packages]
>> +  EmbeddedPkg/EmbeddedPkg.dec
>> +  MdePkg/MdePkg.dec
>> +  Platform/ARM/SgiPkg/SgiPlatform.dec
>> +
>> +[LibraryClasses]
>> +  FdtLib
>> +  PeimEntryPoint
>> +
>> +[Sources]
>> +  SgiPlatformPeiLib.c
>> +
>> +[Guids]
>> +  gArmSgiPlatformIdDescriptorGuid
>> +
>> +[Ppis]
>> +  gHwConfigDtInfoPpiGuid
>> +
>> +[Depex]
>> +  TRUE
>> diff --git a/Platform/ARM/SgiPkg/SgiPlatform.dec b/Platform/ARM/SgiPkg/SgiPlatform.dec
>> index d995937..ea9f6c5 100644
>> --- a/Platform/ARM/SgiPkg/SgiPlatform.dec
>> +++ b/Platform/ARM/SgiPkg/SgiPlatform.dec
>> @@ -29,9 +29,14 @@
>>    Include                        # Root include for the package
>>
>>  [Guids.common]
>> +  # ARM Sgi Platform ID descriptor
>> +  gArmSgiPlatformIdDescriptorGuid = { 0xf56f152a, 0xad2a, 0x11e6, { 0xb1, 0xa7, 0x00, 0x50, 0x56, 0x3c, 0x44, 0xcc } }
>>    gArmSgiTokenSpaceGuid      = { 0x577d6941, 0xaea1, 0x40b4, { 0x90, 0x93, 0x2a, 0x86, 0x61, 0x72, 0x5a, 0x57 } }
>>    gSgi575AcpiTablesiFileGuid = { 0xc712719a, 0x0aaf, 0x438c, { 0x9c, 0xdd, 0x35, 0xab, 0x4d, 0x60, 0x20, 0x7d } }
>>
>>  [PcdsFeatureFlag.common]
>>    # Set this PCD to TRUE to enable virtio support.
>>    gArmSgiTokenSpaceGuid.PcdVirtioSupported|TRUE|BOOLEAN|0x00000001
>> +
>> +[Ppis]
>> +  gHwConfigDtInfoPpiGuid     = { 0x6f606eb3, 0x9123, 0x4e15, { 0xa8, 0x9b, 0x0f, 0xac, 0x66, 0xef, 0xd0, 0x17 } }
>> --
>> 2.7.4
>>