[PATCH v1 5/6] ArmVirtPkg: Add kvmtool platform driver

[Sami Mujawar <sami.mujawar@arm.com>]

The KvmtoolPlatformDxe performs the platform specific
initialization like:
  - It parses the kvmtool DT for Non-Volatile memory
    range to use for runtime variable storage and
    initialises the PcdEmuVariableNvStoreReserved.
  - It decides if the firmware should expose ACPI or
    Device Tree-based hardware description to the
    operating system.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
---
The changes can be seen at https://github.com/samimujawar/edk2/commit/57ffa0da043fd73907b24a6833d2797ea3dae564

Notes:
    v1:
    - Add kvmtool platform driver to support loading platform         [SAMI]
      specific information.

 ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.c   | 211 ++++++++++++++++++++
 ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.inf |  60 ++++++
 2 files changed, 271 insertions(+)

diff --git a/ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.c b/ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.c
new file mode 100644
index 0000000000000000000000000000000000000000..c8c1d50882bb9205194214217d17ed5f3644cc98
--- /dev/null
+++ b/ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.c
@@ -0,0 +1,211 @@
+/** @file
+
+  The KvmtoolPlatformDxe performs the platform specific initialization like:
+  - It parses the kvmtool DT for Non-Volatile memory range to use for runtime
+    variable storage and initialises the PcdEmuVariableNvStoreReserved.
+  - It decides if the firmware should expose ACPI or Device Tree-based
+    hardware description to the operating system.
+
+  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/BaseLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/DebugLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiDriverEntryPoint.h>
+#include <Protocol/FdtClient.h>
+
+/** Parse the kvmtool DT for Non-Volatile Memory range and initialize
+    PcdEmuVariableNvStoreReserved.
+
+  @retval EFI_SUCCESS           Success.
+  @retval EFI_ACCESS_DENIED     Failed to update Pcd.
+  @retval EFI_BUFFER_TOO_SMALL  Non-Volatile memory region less than storage
+                                required for runtime variable storage.
+**/
+STATIC
+EFI_STATUS
+InitializeNvStorageBase (
+  VOID
+)
+{
+  EFI_STATUS                     Status;
+  FDT_CLIENT_PROTOCOL          * FdtClient;
+  INT32                          Node;
+  CONST UINT64                 * Reg;
+  UINT32                         Len;
+  UINT64                         RegSize;
+  UINT64                         RegBase;
+  RETURN_STATUS                  PcdStatus;
+
+  Status = gBS->LocateProtocol (
+                  &gFdtClientProtocolGuid,
+                  NULL,
+                  (VOID **)&FdtClient
+                  );
+  if (EFI_ERROR (Status)) {
+    DEBUG ((
+      DEBUG_ERROR,
+      "Failed to locate Fdt Client Protocol. Status = %r\n",
+      Status
+      ));
+    ASSERT_EFI_ERROR (Status);
+    return Status;
+  }
+
+  Status = FdtClient->FindNextCompatibleNode (
+                        FdtClient,
+                        "kvmtool,NVMem",
+                        Node,
+                        &Node
+                        );
+  if (EFI_ERROR (Status)) {
+    DEBUG ((
+      DEBUG_ERROR,
+      "%a: Cannot find NV memory DT node to use for Runtime variable storage."
+      " Expected node in DT is \'compatible = \"kvmtool,NVMem\"\'."
+      " Status = %r\n",
+       __FUNCTION__,
+       Status
+       ));
+    ASSERT_EFI_ERROR (Status);
+    return Status;
+  }
+
+  Status = FdtClient->GetNodeProperty (
+                        FdtClient,
+                        Node,
+                        "reg",
+                        (CONST VOID **)&Reg,
+                        &Len
+                        );
+  if (EFI_ERROR (Status)) {
+    DEBUG ((
+      DEBUG_ERROR,
+      "%a: GetNodeProperty () failed. Status = %r\n",
+      __FUNCTION__,
+      Status
+      ));
+      return Status;
+  }
+
+  if (Len != (2 * sizeof (UINT64))) {
+    Status = EFI_INVALID_PARAMETER;
+    DEBUG ((
+      DEBUG_ERROR,
+      "%a: Invalid DT Node data. Status = %r\n",
+      __FUNCTION__,
+      Status
+      ));
+      return Status;
+  }
+
+  RegBase = SwapBytes64 (((CONST UINT64 *)Reg)[0]);
+  RegSize = SwapBytes64 (((CONST UINT64 *)Reg)[1]);
+  DEBUG ((DEBUG_INFO, "RegBase = 0x%lx, RegSize = 0x%lx\n", RegBase, RegSize));
+
+  if (RegSize < PcdGet32 (PcdVariableStoreSize)) {
+    DEBUG ((
+      DEBUG_ERROR,
+      "Not enough NV memory available for Runtime variable storage\n"
+      ));
+    return EFI_BUFFER_TOO_SMALL;
+  }
+
+  PcdStatus = PcdSet64S (PcdEmuVariableNvStoreReserved, RegBase);
+  if (RETURN_ERROR (PcdStatus)) {
+    DEBUG ((
+      DEBUG_ERROR,
+      "Failed to update PcdEmuVariableNvStoreReserved. Status = %r\n",
+      PcdStatus
+      ));
+    ASSERT_RETURN_ERROR (PcdStatus);
+    return EFI_ACCESS_DENIED;
+  }
+  return EFI_SUCCESS;
+}
+
+/** Decide if the firmware should expose ACPI tables or Device Tree and
+    install the appropriate protocol interface.
+
+  @param [in]  ImageHandle  Handle for this image.
+
+  @retval EFI_SUCCESS             Success.
+  @retval EFI_OUT_OF_RESOURCES    There was not enough memory to install the
+                                  protocols.
+  @retval EFI_INVALID_PARAMETER   A parameter is invalid.
+
+**/
+STATIC
+EFI_STATUS
+PlatformHasAcpiDt (
+  IN EFI_HANDLE           ImageHandle
+  )
+{
+  if (!PcdGetBool (PcdForceNoAcpi)) {
+    // Expose ACPI tables
+    return gBS->InstallProtocolInterface (
+                  &ImageHandle,
+                  &gEdkiiPlatformHasAcpiGuid,
+                  EFI_NATIVE_INTERFACE,
+                  NULL
+                  );
+  }
+
+  // Expose the Device Tree.
+  return gBS->InstallProtocolInterface (
+                &ImageHandle,
+                &gEdkiiPlatformHasDeviceTreeGuid,
+                EFI_NATIVE_INTERFACE,
+                NULL
+                );
+}
+
+/** Entry point for Kvmtool Platform Dxe
+
+  @param [in]  ImageHandle  Handle for this image.
+  @param [in]  SystemTable  Pointer to the EFI system table.
+
+  @retval EFI_SUCCESS             Success.
+  @retval EFI_OUT_OF_RESOURCES    There was not enough memory to install the
+                                  protocols.
+  @retval EFI_INVALID_PARAMETER   A parameter is invalid.
+
+**/
+EFI_STATUS
+EFIAPI
+KvmtoolPlatformDxeEntryPoint (
+  IN EFI_HANDLE           ImageHandle,
+  IN EFI_SYSTEM_TABLE     *SystemTable
+  )
+{
+  EFI_STATUS                     Status;
+
+  Status = InitializeNvStorageBase ();
+  if (EFI_ERROR (Status)) {
+    goto Failed;
+  }
+
+  Status = PlatformHasAcpiDt (ImageHandle);
+  if (EFI_ERROR (Status)) {
+    goto Failed;
+  }
+
+  return Status;
+
+Failed:
+  ASSERT_EFI_ERROR (Status);
+  CpuDeadLoop ();
+
+  return Status;
+}
diff --git a/ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.inf b/ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.inf
new file mode 100644
index 0000000000000000000000000000000000000000..dddacacdc8e6182e0d063d32e3ae7ff8432c4b20
--- /dev/null
+++ b/ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.inf
@@ -0,0 +1,60 @@
+#/** @file
+#
+#  The KvmtoolPlatformDxe performs the platform specific initialization like:
+#  - It parses the kvmtool DT for Non-Volatile memory range to use for runtime
+#    variable storage and initialises the PcdEmuVariableNvStoreReserved.
+#  - It decides if the firmware should expose ACPI or Device Tree-based
+#    hardware description to the operating system.
+#
+#  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                    = 0x0001001B
+  BASE_NAME                      = KvmtoolPlatformDxe
+  FILE_GUID                      = 7479CCCD-D721-442A-8C73-A72DBB886669
+  MODULE_TYPE                    = DXE_DRIVER
+  VERSION_STRING                 = 1.0
+  ENTRY_POINT                    = KvmtoolPlatformDxeEntryPoint
+
+[Sources]
+  KvmtoolPlatformDxe.c
+
+[Packages]
+  ArmVirtPkg/ArmVirtPkg.dec
+  EmbeddedPkg/EmbeddedPkg.dec
+  MdePkg/MdePkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+
+[LibraryClasses]
+  BaseLib
+  BaseMemoryLib
+  DebugLib
+  MemoryAllocationLib
+  UefiBootServicesTableLib
+  UefiDriverEntryPoint
+
+[Guids]
+  gEdkiiPlatformHasAcpiGuid       ## SOMETIMES_PRODUCES ## PROTOCOL
+  gEdkiiPlatformHasDeviceTreeGuid ## SOMETIMES_PRODUCES ## PROTOCOL
+
+[Pcd]
+  gArmVirtTokenSpaceGuid.PcdForceNoAcpi
+  gEfiMdeModulePkgTokenSpaceGuid.PcdEmuVariableNvStoreReserved
+  gEfiMdeModulePkgTokenSpaceGuid.PcdVariableStoreSize
+
+[Protocols]
+  gFdtClientProtocolGuid                                ## CONSUMES
+
+[Depex]
+  gFdtClientProtocolGuid
-- 
'Guid(CE165669-3EF3-493F-B85D-6190EE5B9759)'