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DynamicTablesPkg: AML tree traversal

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The AML tree traversal provides interfaces to traverse the
nodes in the AML tree.

It provides interfaces to traverse the AML tree in the
following order:

  - Traverse sibling nodes.

    (Node)        /-i           # Child of fixed argument b
        \        /
         |- [a][b][c][d]        # Fixed Arguments
         |- {(e)->(f)->(g)}     # Variable Arguments
               \
                \-h             # Child of variable argument e

    Traversal Order:
      - AmlGetNextSibling() : a, b, c, d, e, f, g, NULL
      - AmlGetPreviousSibling(): g, f, e, d, c, b, a, NULL

  - Iterate depth-first path (follow AML byte stream).
    (Node)        /-i           # Child of fixed argument b
        \        /
         |- [a][b][c][d]        # Fixed Arguments
         |- {(e)->(f)->(g)}     # Variable Arguments
               \
                \-h             # Child of variable argument e

    Traversal Order:
      - AmlGetNextNode(): a, b, i, c, d, e, h, f, g, NULL
      - AmlGetPreviousNode() g, f, h, e, d, c, i, b, a, NULL
        Note: The branch i and h will be traversed if it has
              any children.

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>
This commit is contained in:
Pierre Gondois
2020-08-03 16:30:06 +01:00
committed by mergify[bot]
parent 5764abda7c
commit f96dd8185d
2 changed files with 686 additions and 0 deletions
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138
DynamicTablesPkg/Library/Common/AmlLib/Tree/AmlTreeTraversal.h Normal file
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/** @file
AML Tree Traversal.
Copyright (c) 2019 - 2020, Arm Limited. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#ifndef AML_TREE_TRAVERSAL_H_
#define AML_TREE_TRAVERSAL_H_
#include <AmlNodeDefines.h>
/** Get the next sibling node among the children of the input Node.
This function traverses the FixedArguments followed by the
VariableArguments at the same level in the hierarchy.
Fixed arguments are before variable arguments.
(Node) /-i # Child of fixed argument b
\ /
|- [a][b][c][d] # Fixed Arguments
|- {(e)->(f)->(g)} # Variable Arguments
\
\-h # Child of variable argument e
Traversal Order: a, b, c, d, e, f, g, NULL
@param [in] Node Pointer to a root node or an object node.
@param [in] ChildNode Get the node after the ChildNode.
@return The node after the ChildNode among the children of the input Node.
- If ChildNode is NULL, return the first available node among
the fixed argument list then variable list of arguments;
- If ChildNode is the last node of the fixed argument list,
return the first argument of the variable list of arguments;
- If ChildNode is the last node of the variable list of arguments,
return NULL.
**/
AML_NODE_HEADER *
EFIAPI
AmlGetNextSibling (
IN CONST AML_NODE_HEADER * Node,
IN CONST AML_NODE_HEADER * ChildNode
);
/** Get the previous sibling node among the children of the input Node.
This function traverses the FixedArguments followed by the
VariableArguments at the same level in the hierarchy.
Fixed arguments are before variable arguments.
(Node) /-i # Child of fixed argument b
\ /
|- [a][b][c][d] # Fixed Arguments
|- {(e)->(f)->(g)} # Variable Arguments
\
\-h # Child of variable argument e
Traversal Order: g, f, e, d, c, b, a, NULL
@param [in] Node The node to get the fixed argument from.
@param [in] ChildNode Get the node before the ChildNode.
@return The node before the ChildNode among the children of the input Node.
- If ChildNode is NULL, return the last available node among
the variable list of arguments then fixed argument list;
- If ChildNode is the first node of the variable list of arguments,
return the last argument of the fixed argument list;
- If ChildNode is the first node of the fixed argument list,
return NULL.
**/
AML_NODE_HEADER *
EFIAPI
AmlGetPreviousSibling (
IN CONST AML_NODE_HEADER * Node,
IN CONST AML_NODE_HEADER * ChildNode
);
/** Iterate through the nodes in the same order as the AML bytestream.
The iteration is similar to a depth-first path.
(Node) /-i # Child of fixed argument b
\ /
|- [a][b][c][d] # Fixed Arguments
|- {(e)->(f)->(g)} # Variable Arguments
\
\-h # Child of variable argument e
Traversal Order: a, b, i, c, d, e, h, f, g, NULL
Note: The branch i and h will be traversed if it has any children.
@param [in] Node Pointer to a node.
@return The next node in the AML bytestream order.
Return NULL if Node is the Node corresponding to the last
bytecode of the tree.
**/
AML_NODE_HEADER *
EFIAPI
AmlGetNextNode (
IN CONST AML_NODE_HEADER * Node
);
/** Iterate through the nodes in the reverse order of the AML bytestream.
The iteration is similar to a depth-first path,
but done in a reverse order.
(Node) /-i # Child of fixed argument b
\ /
|- [a][b][c][d] # Fixed Arguments
|- {(e)->(f)->(g)} # Variable Arguments
\
\-h # Child of variable argument e
Traversal Order: g, f, h, e, d, c, i, b, a, NULL
Note: The branch i and h will be traversed if it has any children.
@param [in] Node Pointer to a node.
@return The previous node in the AML bytestream order.
Return NULL if Node is the Node corresponding to the last
bytecode of the tree.
**/
AML_NODE_HEADER *
EFIAPI
AmlGetPreviousNode (
IN CONST AML_NODE_HEADER * Node
);
#endif // AML_TREE_TRAVERSAL_H_