DynamicTablesPkg: Add AmlCodeGenMethodRetInteger function

Add AmlCodeGenMethodRetInteger function to generate AML code for
a Method returning an Integer.

Signed-off-by: Rebecca Cran <quic_rcran@quicinc.com>
Reviewed-by: Pierre Gondois <pierre.gondois@arm.com>
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>

DynamicTablesPkg/Include/Library/AmlLib/AmlLib.h

@@ -1118,6 +1118,53 @@ AmlCodeGenMethodRetNameString (
   OUT       AML_OBJECT_NODE_HANDLE  *NewObjectNode        OPTIONAL
   );
 
+/** AML code generation for a method returning an Integer.
+
+  AmlCodeGenMethodRetInteger (
+    "_CBA", 0, 1, TRUE, 3, ParentNode, NewObjectNode
+    );
+  is equivalent of the following ASL code:
+    Method(_CBA, 1, Serialized, 3) {
+      Return (0)
+    }
+
+  The ASL parameters "ReturnType" and "ParameterTypes" are not asked
+  in this function. They are optional parameters in ASL.
+
+  @param [in]  MethodNameString     The new Method's name.
+                                    Must be a NULL-terminated ASL NameString
+                                    e.g.: "MET0", "_SB.MET0", etc.
+                                    The input string is copied.
+  @param [in]  ReturnedInteger      The value of the integer returned by the
+                                    method.
+  @param [in]  NumArgs              Number of arguments.
+                                    Must be 0 <= NumArgs <= 6.
+  @param [in]  IsSerialized         TRUE is equivalent to Serialized.
+                                    FALSE is equivalent to NotSerialized.
+                                    Default is NotSerialized in ASL spec.
+  @param [in]  SyncLevel            Synchronization level for the method.
+                                    Must be 0 <= SyncLevel <= 15.
+                                    Default is 0 in ASL.
+  @param [in]  ParentNode           If provided, set ParentNode as the parent
+                                    of the node created.
+  @param [out] NewObjectNode        If success, contains the created node.
+
+  @retval EFI_SUCCESS             Success.
+  @retval EFI_INVALID_PARAMETER   Invalid parameter.
+  @retval EFI_OUT_OF_RESOURCES    Failed to allocate memory.
+**/
+EFI_STATUS
+EFIAPI
+AmlCodeGenMethodRetInteger (
+  IN  CONST CHAR8                   *MethodNameString,
+  IN        UINT64                  ReturnedInteger,
+  IN        UINT8                   NumArgs,
+  IN        BOOLEAN                 IsSerialized,
+  IN        UINT8                   SyncLevel,
+  IN        AML_NODE_HANDLE         ParentNode           OPTIONAL,
+  OUT       AML_OBJECT_NODE_HANDLE  *NewObjectNode        OPTIONAL
+  );
+
 /** Create a _LPI name.
 
   AmlCreateLpiNode ("_LPI", 0, 1, ParentNode, &LpiNode) is

DynamicTablesPkg/Library/Common/AmlLib/CodeGen/AmlCodeGen.c

@@ -1706,6 +1706,64 @@ exit_handler:
   return Status;
 }
 
+/** AML code generation for a Return object node,
+    returning an Integer.
+
+  AmlCodeGenReturn (0), ParentNode, NewObjectNode) is
+  equivalent of the following ASL code:
+    Return (0)
+
+  The ACPI 6.3 specification, 20.2.8 "Statement Opcodes Encoding" states:
+    DefReturn := ReturnOp ArgObject
+    ReturnOp := 0xA4
+    ArgObject := TermArg => DataRefObject
+
+  Thus, the ReturnNode must be evaluated as a DataRefObject.
+
+  The ReturnNode must be generated inside a Method body scope.
+
+  @param [in]  Integer        The integer is returned by the Return
+                              ASL statement.
+  @param [in]  ParentNode     If provided, set ParentNode as the parent
+                              of the node created.
+                              Must be a MethodOp node.
+  @param [out] NewObjectNode  If success, contains the created node.
+
+  @retval EFI_SUCCESS             Success.
+  @retval EFI_INVALID_PARAMETER   Invalid parameter.
+  @retval EFI_OUT_OF_RESOURCES    Failed to allocate memory.
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+AmlCodeGenReturnInteger (
+  IN        UINT64           Integer,
+  IN        AML_NODE_HEADER  *ParentNode      OPTIONAL,
+  OUT       AML_OBJECT_NODE  **NewObjectNode  OPTIONAL
+  )
+{
+  EFI_STATUS       Status;
+  AML_OBJECT_NODE  *IntNode;
+
+  IntNode = NULL;
+
+  Status = AmlCodeGenInteger (Integer, &IntNode);
+  if (EFI_ERROR (Status)) {
+    ASSERT (0);
+    return Status;
+  }
+
+  // AmlCodeGenReturn() deletes DataNode if error.
+  Status = AmlCodeGenReturn (
+             (AML_NODE_HEADER *)IntNode,
+             ParentNode,
+             NewObjectNode
+             );
+  ASSERT_EFI_ERROR (Status);
+
+  return Status;
+}
+
 /** AML code generation for a method returning a NameString.
 
   AmlCodeGenMethodRetNameString (
@@ -1814,6 +1872,107 @@ error_handler:
   return Status;
 }
 
+/** AML code generation for a method returning an Integer.
+
+  AmlCodeGenMethodRetInteger (
+    "_CBA", 0, 1, TRUE, 3, ParentNode, NewObjectNode
+    );
+  is equivalent of the following ASL code:
+    Method(_CBA, 1, Serialized, 3) {
+      Return (0)
+    }
+
+  The ASL parameters "ReturnType" and "ParameterTypes" are not asked
+  in this function. They are optional parameters in ASL.
+
+  @param [in]  MethodNameString     The new Method's name.
+                                    Must be a NULL-terminated ASL NameString
+                                    e.g.: "MET0", "_SB.MET0", etc.
+                                    The input string is copied.
+  @param [in]  ReturnedInteger      The value of the integer returned by the
+                                    method.
+  @param [in]  NumArgs              Number of arguments.
+                                    Must be 0 <= NumArgs <= 6.
+  @param [in]  IsSerialized         TRUE is equivalent to Serialized.
+                                    FALSE is equivalent to NotSerialized.
+                                    Default is NotSerialized in ASL spec.
+  @param [in]  SyncLevel            Synchronization level for the method.
+                                    Must be 0 <= SyncLevel <= 15.
+                                    Default is 0 in ASL.
+  @param [in]  ParentNode           If provided, set ParentNode as the parent
+                                    of the node created.
+  @param [out] NewObjectNode        If success, contains the created node.
+
+  @retval EFI_SUCCESS             Success.
+  @retval EFI_INVALID_PARAMETER   Invalid parameter.
+  @retval EFI_OUT_OF_RESOURCES    Failed to allocate memory.
+**/
+EFI_STATUS
+EFIAPI
+AmlCodeGenMethodRetInteger (
+  IN  CONST CHAR8                   *MethodNameString,
+  IN        UINT64                  ReturnedInteger,
+  IN        UINT8                   NumArgs,
+  IN        BOOLEAN                 IsSerialized,
+  IN        UINT8                   SyncLevel,
+  IN        AML_NODE_HANDLE         ParentNode      OPTIONAL,
+  OUT       AML_OBJECT_NODE_HANDLE  *NewObjectNode  OPTIONAL
+  )
+{
+  EFI_STATUS              Status;
+  AML_OBJECT_NODE_HANDLE  MethodNode;
+
+  if ((MethodNameString == NULL)  ||
+      ((ParentNode == NULL) && (NewObjectNode == NULL)))
+  {
+    ASSERT (0);
+    return EFI_INVALID_PARAMETER;
+  }
+
+  // Create a Method named MethodNameString.
+  Status = AmlCodeGenMethod (
+             MethodNameString,
+             NumArgs,
+             IsSerialized,
+             SyncLevel,
+             NULL,
+             &MethodNode
+             );
+  if (EFI_ERROR (Status)) {
+    ASSERT (0);
+    return Status;
+  }
+
+  Status = AmlCodeGenReturnInteger (
+             ReturnedInteger,
+             (AML_NODE_HANDLE)MethodNode,
+             NULL
+             );
+  if (EFI_ERROR (Status)) {
+    ASSERT (0);
+    goto error_handler;
+  }
+
+  Status = LinkNode (
+             MethodNode,
+             ParentNode,
+             NewObjectNode
+             );
+  if (EFI_ERROR (Status)) {
+    ASSERT (0);
+    goto error_handler;
+  }
+
+  return Status;
+
+error_handler:
+  if (MethodNode != NULL) {
+    AmlDeleteTree ((AML_NODE_HANDLE)MethodNode);
+  }
+
+  return Status;
+}
+
 /** Create a _LPI name.
 
   AmlCreateLpiNode ("_LPI", 0, 1, ParentNode, &LpiNode) is