Re: [PATCH edk2-platforms 5/8] Silicon/SynQuacer: disable PCI RC #0 DT node if disabled

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

On 12 December 2017 at 10:38, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote:
> If PCIe RC #0 is not enabled (due to the fact that the slot is not
> populated), set its DT node 'status' property to 'disabled' so that
> the OS will not attempt to attach to it.
>
> This means we will need to switch from the default DtPlatformDtbLoaderLib
> to a special one for our platform.
>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> ---
>  Platform/Socionext/DeveloperBox/DeveloperBox.dsc                                    |  8 +-
>  Platform/Socionext/SynQuacerEvalBoard/SynQuacerEvalBoard.dsc                        |  3 +-
>  Silicon/Socionext/SynQuacer/Library/SynQuacerDtbLoaderLib/SynQuacerDtbLoaderLib.c   | 94 ++++++++++++++++++++
>  Silicon/Socionext/SynQuacer/Library/SynQuacerDtbLoaderLib/SynQuacerDtbLoaderLib.inf | 42 +++++++++
>  4 files changed, 141 insertions(+), 6 deletions(-)
>
> diff --git a/Platform/Socionext/DeveloperBox/DeveloperBox.dsc b/Platform/Socionext/DeveloperBox/DeveloperBox.dsc
> index 5ec26f9cdd34..80728fedbc20 100644
> --- a/Platform/Socionext/DeveloperBox/DeveloperBox.dsc
> +++ b/Platform/Socionext/DeveloperBox/DeveloperBox.dsc
> @@ -160,7 +160,8 @@ [LibraryClasses.common.DXE_CORE]
>    PerformanceLib|MdeModulePkg/Library/DxeCorePerformanceLib/DxeCorePerformanceLib.inf
>
>  [LibraryClasses.common.DXE_DRIVER]
> -  DtPlatformDtbLoaderLib|EmbeddedPkg/Library/DxeDtPlatformDtbLoaderLibDefault/DxeDtPlatformDtbLoaderLibDefault.inf
> +  DtPlatformDtbLoaderLib|Silicon/Socionext/SynQuacer/Library/SynQuacerDtbLoaderLib/SynQuacerDtbLoaderLib.inf
> +  FdtLib|EmbeddedPkg/Library/FdtLib/FdtLib.inf
>    SecurityManagementLib|MdeModulePkg/Library/DxeSecurityManagementLib/DxeSecurityManagementLib.inf
>    PerformanceLib|MdeModulePkg/Library/DxePerformanceLib/DxePerformanceLib.inf
>
> @@ -611,10 +612,7 @@ [Components.common]
>    #
>    # Console preference selection
>    #
> -  EmbeddedPkg/Drivers/ConsolePrefDxe/ConsolePrefDxe.inf {
> -    <LibraryClasses>
> -      FdtLib|EmbeddedPkg/Library/FdtLib/FdtLib.inf
> -  }
> +  EmbeddedPkg/Drivers/ConsolePrefDxe/ConsolePrefDxe.inf
>
>    #
>    # DT support
> diff --git a/Platform/Socionext/SynQuacerEvalBoard/SynQuacerEvalBoard.dsc b/Platform/Socionext/SynQuacerEvalBoard/SynQuacerEvalBoard.dsc
> index bc8ddd452d4b..c71425664bdc 100644
> --- a/Platform/Socionext/SynQuacerEvalBoard/SynQuacerEvalBoard.dsc
> +++ b/Platform/Socionext/SynQuacerEvalBoard/SynQuacerEvalBoard.dsc
> @@ -159,7 +159,8 @@ [LibraryClasses.common.DXE_CORE]
>    PerformanceLib|MdeModulePkg/Library/DxeCorePerformanceLib/DxeCorePerformanceLib.inf
>
>  [LibraryClasses.common.DXE_DRIVER]
> -  DtPlatformDtbLoaderLib|EmbeddedPkg/Library/DxeDtPlatformDtbLoaderLibDefault/DxeDtPlatformDtbLoaderLibDefault.inf
> +  DtPlatformDtbLoaderLib|Silicon/Socionext/SynQuacer/Library/SynQuacerDtbLoaderLib/SynQuacerDtbLoaderLib.inf
> +  FdtLib|EmbeddedPkg/Library/FdtLib/FdtLib.inf
>    SecurityManagementLib|MdeModulePkg/Library/DxeSecurityManagementLib/DxeSecurityManagementLib.inf
>    PerformanceLib|MdeModulePkg/Library/DxePerformanceLib/DxePerformanceLib.inf
>
> diff --git a/Silicon/Socionext/SynQuacer/Library/SynQuacerDtbLoaderLib/SynQuacerDtbLoaderLib.c b/Silicon/Socionext/SynQuacer/Library/SynQuacerDtbLoaderLib/SynQuacerDtbLoaderLib.c
> new file mode 100644
> index 000000000000..a93a6027e64d
> --- /dev/null
> +++ b/Silicon/Socionext/SynQuacer/Library/SynQuacerDtbLoaderLib/SynQuacerDtbLoaderLib.c
> @@ -0,0 +1,94 @@
> +/** @file
> +*
> +*  Copyright (c) 2017, Linaro, Ltd. 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 <PiDxe.h>
> +
> +#include <libfdt.h>
> +#include <Library/BaseLib.h>
> +#include <Library/DebugLib.h>
> +#include <Library/DxeServicesLib.h>
> +#include <Library/MemoryAllocationLib.h>
> +
> +#define DTB_PADDING               64
> +
> +STATIC
> +VOID
> +DisableDtNode (
> +  IN  VOID                        *Dtb,
> +  IN  CONST CHAR8                 *NodePath
> +  )
> +{
> +  INT32                           Node;
> +  INT32                           Rc;
> +
> +  Node = fdt_path_offset (Dtb, NodePath);
> +  if (Node < 0) {
> +    DEBUG ((DEBUG_ERROR, "%a: failed to locate DT path '%a': %a\n",
> +      __FUNCTION__, NodePath, fdt_strerror (Node)));
> +    return;
> +  }
> +  Rc = fdt_setprop_string (Dtb, Node, "status", "disabled");
> +  if (Rc < 0) {
> +    DEBUG ((DEBUG_ERROR, "%a: failed to set status to 'disabled' on '%a': %a\n",
> +      __FUNCTION__, NodePath, fdt_strerror (Rc)));
> +  }
> +}
> +
> +/**
> +  Return a pool allocated copy of the DTB image that is appropriate for
> +  booting the current platform via DT.
> +
> +  @param[out]   Dtb                   Pointer to the DTB copy
> +  @param[out]   DtbSize               Size of the DTB copy
> +
> +  @retval       EFI_SUCCESS           Operation completed successfully
> +  @retval       EFI_NOT_FOUND         No suitable DTB image could be located
> +  @retval       EFI_OUT_OF_RESOURCES  No pool memory available
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +DtPlatformLoadDtb (
> +  OUT   VOID        **Dtb,
> +  OUT   UINTN       *DtbSize
> +  )
> +{
> +  EFI_STATUS      Status;
> +  VOID            *OrigDtb;
> +  VOID            *CopyDtb;
> +  UINTN           OrigDtbSize;
> +
> +  Status = GetSectionFromAnyFv (&gDtPlatformDefaultDtbFileGuid,
> +             EFI_SECTION_RAW, 0, &OrigDtb, &OrigDtbSize);
> +  if (EFI_ERROR (Status)) {
> +    return EFI_NOT_FOUND;
> +  }
> +
> +  CopyDtb = AllocateCopyPool (OrigDtbSize + DTB_PADDING, OrigDtb);
> +  if (CopyDtb == NULL) {
> +    return EFI_OUT_OF_RESOURCES;
> +  }
> +
> +  if (!(PcdGet8 (PcdPcieEnableMask) & BIT0)) {
> +    DisableDtNode (CopyDtb, "/pcie@60000000");
> +  }
> +  if (!(PcdGet8 (PcdPcieEnableMask) & BIT1)) {
> +    DisableDtNode (CopyDtb, "/pcie@70000000");
> +  }
> +
> +  *Dtb = CopyDtb;
> +  *DtbSize = OrigDtbSize + DTB_PADDING;
> +
> +  return EFI_SUCCESS;
> +}

This needs a tweak: I forgot to incorporate the fdt_copy_into() call
which grows the DTB image before adding properties. The following
needs to be applied on top.

--- a/Silicon/Socionext/SynQuacer/Library/SynQuacerDtbLoaderLib/SynQuacerDtbLoaderLib.c
+++ b/Silicon/Socionext/SynQuacer/Library/SynQuacerDtbLoaderLib/SynQuacerDtbLoaderLib.c
@@ -68,6 +68,8 @@ DtPlatformLoadDtb (
   VOID            *OrigDtb;
   VOID            *CopyDtb;
   UINTN           OrigDtbSize;
+  UINTN           CopyDtbSize;
+  INT32           Rc;

   Status = GetSectionFromAnyFv (&gDtPlatformDefaultDtbFileGuid,
              EFI_SECTION_RAW, 0, &OrigDtb, &OrigDtbSize);
@@ -75,11 +77,19 @@ DtPlatformLoadDtb (
     return EFI_NOT_FOUND;
   }

-  CopyDtb = AllocateCopyPool (OrigDtbSize + DTB_PADDING, OrigDtb);
+  CopyDtbSize = OrigDtbSize + DTB_PADDING;
+  CopyDtb = AllocatePool (CopyDtbSize);
   if (CopyDtb == NULL) {
     return EFI_OUT_OF_RESOURCES;
   }

+  Rc = fdt_open_into (OrigDtb, CopyDtb, CopyDtbSize);
+  if (Rc < 0) {
+    DEBUG ((DEBUG_ERROR, "%a: fdt_open_into () failed: %a\n", __FUNCTION__,
+      fdt_strerror (Rc)));
+    return EFI_NOT_FOUND;
+  }
+
   if (!(PcdGet8 (PcdPcieEnableMask) & BIT0)) {
     DisableDtNode (CopyDtb, "/pcie@60000000");
   }
@@ -88,7 +98,7 @@ DtPlatformLoadDtb (
   }

   *Dtb = CopyDtb;
-  *DtbSize = OrigDtbSize + DTB_PADDING;
+  *DtbSize = CopyDtbSize;

   return EFI_SUCCESS;
 }