[PATCH v3 04/15] DynamicTablesPkg: FdtHwInfoParser: Add Boot Arch parser

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

From: Pierre Gondois <Pierre.Gondois@arm.com>

The Fixed ACPI Description Table (FADT) is a mandatory table
required for booting a standards-based operating system. The
FADT table has an 'ARM Boot Architecture Flags' field that is
used by an OS at boot time to determine the code path during
boot. This field is used to specify if the platform complies
with the PSCI specification. It is also used to describe the
conduit (SMC/HVC) to be used for PSCI.

The PSCI compliance information for a platform is described
in the platform Device Tree, the bindings for which can be
found at:
 - linux/Documentation/devicetree/bindings/arm/psci.yaml

The FdtHwInfoParser implements a Boot Arch Parser that parses
the platform Device Tree to create a CM_ARM_BOOT_ARCH_INFO
object. The CM_ARM_BOOT_ARCH_INFO object is encapsulated in
a Configuration Manager descriptor object and added to the
platform information repository.

The platform Configuration Manager can then utilise this
information when generating the FADT table.

Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com>
---
 .../BootArch/ArmBootArchParser.c              | 159 ++++++++++++++++++
 .../BootArch/ArmBootArchParser.h              |  45 +++++
 2 files changed, 204 insertions(+)
 create mode 100644 DynamicTablesPkg/Library/FdtHwInfoParserLib/BootArch/ArmBootArchParser.c
 create mode 100644 DynamicTablesPkg/Library/FdtHwInfoParserLib/BootArch/ArmBootArchParser.h

diff --git a/DynamicTablesPkg/Library/FdtHwInfoParserLib/BootArch/ArmBootArchParser.c b/DynamicTablesPkg/Library/FdtHwInfoParserLib/BootArch/ArmBootArchParser.c
new file mode 100644
index 000000000000..5040e50eb16a
--- /dev/null
+++ b/DynamicTablesPkg/Library/FdtHwInfoParserLib/BootArch/ArmBootArchParser.c
@@ -0,0 +1,159 @@
+/** @file
+  Arm boot architecture parser.
+
+  Copyright (c) 2021, ARM Limited. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+  @par Reference(s):
+  - linux/Documentation/devicetree/bindings/arm/psci.yaml
+**/
+
+#include "FdtHwInfoParser.h"
+#include "CmObjectDescUtility.h"
+#include "BootArch/ArmBootArchParser.h"
+
+/** List of "compatible" property values for Psci nodes.
+
+  Other "compatible" values are not supported by this module.
+*/
+STATIC CONST COMPATIBILITY_STR PsciCompatibleStr[] = {
+  {"arm,psci-0.2"},
+  {"arm,psci"}
+};
+
+/** COMPATIBILITY_INFO structure for the PsciCompatibleInfo.
+*/
+STATIC CONST COMPATIBILITY_INFO PsciCompatibleInfo = {
+  ARRAY_SIZE (PsciCompatibleStr),
+  PsciCompatibleStr
+};
+
+/** List of PSCI method strings.
+*/
+STATIC CONST CHAR8  *PsciMethod[] = {
+  "smc",
+  "hvc"
+};
+
+/** Parse a Psci node.
+
+  @param [in]  Fdt            Pointer to a Flattened Device Tree (Fdt).
+  @param [in]  PsciNode       Offset of a Psci node.
+  @param [in]  BootArchInfo   The CM_ARM_BOOT_ARCH_INFO to populate.
+
+  @retval EFI_SUCCESS             The function completed successfully.
+  @retval EFI_ABORTED             An error occurred.
+  @retval EFI_INVALID_PARAMETER   Invalid parameter.
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+PsciNodeParser (
+  IN  CONST VOID                    * Fdt,
+  IN        INT32                     PsciNode,
+  IN        CM_ARM_BOOT_ARCH_INFO   * BootArchInfo
+  )
+{
+  CONST VOID    * Data;
+  INT32           DataSize;
+
+  if ((Fdt == NULL) ||
+      (BootArchInfo == NULL)) {
+    ASSERT (0);
+    return EFI_INVALID_PARAMETER;
+  }
+
+  // Default to parking protocol
+  BootArchInfo->BootArchFlags = 0;
+
+  Data = fdt_getprop (Fdt, PsciNode, "method", &DataSize);
+  if ((Data == NULL) || (DataSize < 0)) {
+    ASSERT (0);
+    return EFI_ABORTED;
+  }
+
+  // Check PSCI conduit.
+  if (AsciiStrnCmp (Data, PsciMethod[0], DataSize) == 0) {
+    BootArchInfo->BootArchFlags = EFI_ACPI_6_3_ARM_PSCI_COMPLIANT;
+
+  } else if (AsciiStrnCmp (Data, PsciMethod[1], DataSize) == 0) {
+    BootArchInfo->BootArchFlags = (EFI_ACPI_6_3_ARM_PSCI_COMPLIANT |
+                                   EFI_ACPI_6_3_ARM_PSCI_USE_HVC);
+  }
+
+  return EFI_SUCCESS;
+}
+
+/** CM_ARM_BOOT_ARCH_INFO parser function.
+
+  The following structure is populated:
+  typedef struct CmArmBootArchInfo {
+    UINT16  BootArchFlags;                    // {Populated}
+  } CM_ARM_BOOT_ARCH_INFO;
+
+  A parser parses a Device Tree to populate a specific CmObj type. None,
+  one or many CmObj can be created by the parser.
+  The created CmObj are then handed to the parser's caller through the
+  HW_INFO_ADD_OBJECT interface.
+  This can also be a dispatcher. I.e. a function that not parsing a
+  Device Tree but calling other parsers.
+
+  @param [in]  FdtParserHandle A handle to the parser instance.
+  @param [in]  FdtBranch       When searching for DT node name, restrict
+                               the search to this Device Tree branch.
+
+  @retval EFI_SUCCESS             The function completed successfully.
+  @retval EFI_ABORTED             An error occurred.
+  @retval EFI_INVALID_PARAMETER   Invalid parameter.
+  @retval EFI_NOT_FOUND           Not found.
+  @retval EFI_UNSUPPORTED         Unsupported.
+**/
+EFI_STATUS
+EFIAPI
+ArmBootArchInfoParser (
+  IN  CONST FDT_HW_INFO_PARSER_HANDLE FdtParserHandle,
+  IN        INT32                     FdtBranch
+  )
+{
+  EFI_STATUS               Status;
+  INT32                    PsciNode;
+  CM_ARM_BOOT_ARCH_INFO    BootArchInfo;
+
+  if (FdtParserHandle == NULL) {
+    ASSERT (0);
+    return EFI_INVALID_PARAMETER;
+  }
+
+  ZeroMem (&BootArchInfo, sizeof (CM_ARM_BOOT_ARCH_INFO));
+
+  PsciNode = FdtBranch;
+  Status = FdtGetNextCompatNodeInBranch (
+             FdtParserHandle->Fdt,
+             FdtBranch,
+             &PsciCompatibleInfo,
+             &PsciNode
+             );
+  if (EFI_ERROR (Status)) {
+    // Error, or no node found.
+    ASSERT (Status == EFI_NOT_FOUND);
+    return Status;
+  }
+
+  // Parse the psci node.
+  Status = PsciNodeParser (FdtParserHandle->Fdt, PsciNode, &BootArchInfo);
+  if (EFI_ERROR (Status)) {
+    ASSERT (0);
+    return Status;
+  }
+
+  // Add the CmObj to the Configuration Manager.
+  Status = AddSingleCmObj (
+             FdtParserHandle,
+             CREATE_CM_ARM_OBJECT_ID (EArmObjBootArchInfo),
+             &BootArchInfo,
+             sizeof (CM_ARM_BOOT_ARCH_INFO),
+             NULL
+             );
+  ASSERT_EFI_ERROR (Status);
+  return Status;
+}
diff --git a/DynamicTablesPkg/Library/FdtHwInfoParserLib/BootArch/ArmBootArchParser.h b/DynamicTablesPkg/Library/FdtHwInfoParserLib/BootArch/ArmBootArchParser.h
new file mode 100644
index 000000000000..959c65a53fb3
--- /dev/null
+++ b/DynamicTablesPkg/Library/FdtHwInfoParserLib/BootArch/ArmBootArchParser.h
@@ -0,0 +1,45 @@
+/** @file
+  Arm boot architecture parser.
+
+  Copyright (c) 2021, ARM Limited. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+  @par Reference(s):
+  - linux/Documentation/devicetree/bindings/arm/psci.yaml
+**/
+
+#ifndef ARM_BOOT_ARCH_PARSER_H_
+#define ARM_BOOT_ARCH_PARSER_H_
+
+/** CM_ARM_BOOT_ARCH_INFO parser function.
+
+  The following structure is populated:
+  typedef struct CmArmBootArchInfo {
+    UINT16  BootArchFlags;                    // {Populated}
+  } CM_ARM_BOOT_ARCH_INFO;
+
+  A parser parses a Device Tree to populate a specific CmObj type. None,
+  one or many CmObj can be created by the parser.
+  The created CmObj are then handed to the parser's caller through the
+  HW_INFO_ADD_OBJECT interface.
+  This can also be a dispatcher. I.e. a function that not parsing a
+  Device Tree but calling other parsers.
+
+  @param [in]  FdtParserHandle A handle to the parser instance.
+  @param [in]  FdtBranch       When searching for DT node name, restrict
+                               the search to this Device Tree branch.
+
+  @retval EFI_SUCCESS             The function completed successfully.
+  @retval EFI_ABORTED             An error occurred.
+  @retval EFI_INVALID_PARAMETER   Invalid parameter.
+  @retval EFI_NOT_FOUND           Not found.
+  @retval EFI_UNSUPPORTED         Unsupported.
+**/
+EFI_STATUS
+EFIAPI
+ArmBootArchInfoParser (
+  IN  CONST FDT_HW_INFO_PARSER_HANDLE FdtParserHandle,
+  IN        INT32                     FdtBranch
+  );
+
+#endif // ARM_BOOT_ARCH_PARSER_H_
-- 
2.25.1