DynamicTablesPkg: AML ACPI Namespace interface

AML is a declarative language that is processed by the
ACPI AML interpreter. The ACPI AML interpreter will
compile the set of declarations into the ACPI Namespace
at definition block load time.

The hardware information described in AML is effectively
mapped in the ACPI Namespace. The AML ACPI namespace
interface implement the functionality to search the ACPI
Namespace. Example: The AmlFindNode() can be used to locate
a device node in the ACPI namespace using an ASL path as
the search input.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Reviewed-by: Alexei Fedorov <Alexei.Fedorov@arm.com>

DynamicTablesPkg/Library/Common/AmlLib/NameSpace/AmlNameSpace.h

@@ -0,0 +1,74 @@
+/** @file
+  AML NameSpace.
+
+  Copyright (c) 2019 - 2020, Arm Limited. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#ifndef AML_NAMESPACE_H_
+#define AML_NAMESPACE_H_
+
+#include <AmlNodeDefines.h>
+#include <Stream/AmlStream.h>
+
+/** Return the first AML namespace node up in the parent hierarchy.
+
+    Return the root node if no namespace node is found is the hierarchy.
+
+  @param  [in]  Node      Node to look at the parents from.
+                          If Node is the root node, OutNode is NULL.
+  @param  [out] OutNode   If a namespace node is found, pointer to the
+                          first namespace node of Node's parents.
+                          Stop at the root node otherwise.
+
+  @retval EFI_SUCCESS             The function completed successfully.
+  @retval EFI_INVALID_PARAMETER   Invalid parameter.
+  **/
+EFI_STATUS
+EFIAPI
+AmlGetFirstAncestorNameSpaceNode (
+  IN  CONST AML_NODE_HEADER   * Node,
+  OUT       AML_NODE_HEADER  ** OutNode
+  );
+
+/** Build the raw absolute AML pathname to Node and write it to a stream.
+
+  A raw AML pathname is an AML pathname where the root char ('\'),
+  prefix chars ('^') and NameString prefix byte (e.g.: DualNamePrefix)
+  have been removed. A raw AML pathname is a list of concatenated
+  NameSegs.
+
+  E.g.:
+  ASL absolute path:  "[RootChar]AAAA.BBBB.CCCC\0"
+  AML absolute path:  "[RootChar][MultiNamePrefix][3(NameSegs)]AAAABBBBCCCC"
+  Raw absolute path:  "AAAABBBBCCCC"
+
+  @param  [in]   Node         Node to build the raw absolute path to
+                              Must be a root node, or a namespace node.
+  @param  [in]  InputParent   Skip InputParent AML namespace levels before
+                              starting building the raw absolute pathname.
+                              E.g.: - Node's name being "^AAAA.BBBB.CCCC";
+                                    - InputParent = 2;
+                                    "BBBB.CCCC" will be skipped (2
+                                    levels), and "^AAAA" will remain. The
+                                    first caret is not related to InputParent.
+  @param  [out]  RawAbsPathBStream  Backward stream to write the raw
+                                    pathname to.
+                                    If Node is the root node, the Stream data
+                                    Buffer will stay empty.
+                                    The stream must not be at its end.
+
+  @retval EFI_SUCCESS             The function completed successfully.
+  @retval EFI_BUFFER_TOO_SMALL    No space left in the buffer.
+  @retval EFI_INVALID_PARAMETER   Invalid parameter.
+**/
+EFI_STATUS
+EFIAPI
+AmlGetRawNameSpacePath (
+  IN  CONST AML_NODE_HEADER   * Node,
+  IN        UINT32              InputParent,
+  OUT       AML_STREAM        * RawAbsPathBStream
+  );
+
+#endif // AML_NAMESPACE_H_