ACPICA: Implement deferred resolution of reference package elements

ACPICA commit 0c08790c56fdf0dc081ae869495a09d8c4230854

This change defers the resolution of package elements that
are named references until after the entire namespace has been
loaded from the definition block. This allows such references
to be in fact forward references for both module level code
and control methods.

Link: https://github.com/acpica/acpica/commit/0c08790c
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 496 insertions, 0 deletions

diff --git a/drivers/acpi/acpica/dspkginit.c b/drivers/acpi/acpica/dspkginit.c
new file mode 100644
index 000000000000..6d487edfe2de
--- /dev/null
+++ b/drivers/acpi/acpica/dspkginit.c
@@ -0,0 +1,496 @@
+/******************************************************************************
+ *
+ * Module Name: dspkginit - Completion of deferred package initialization
+ *
+ *****************************************************************************/
+
+/*
+ * Copyright (C) 2000 - 2017, Intel Corp.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions, and the following disclaimer,
+ *    without modification.
+ * 2. Redistributions in binary form must reproduce at minimum a disclaimer
+ *    substantially similar to the "NO WARRANTY" disclaimer below
+ *    ("Disclaimer") and any redistribution must be conditioned upon
+ *    including a substantially similar Disclaimer requirement for further
+ *    binary redistribution.
+ * 3. Neither the names of the above-listed copyright holders nor the names
+ *    of any contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * NO WARRANTY
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGES.
+ */
+
+#include <acpi/acpi.h>
+#include "accommon.h"
+#include "acnamesp.h"
+#include "amlcode.h"
+#include "acdispat.h"
+#include "acinterp.h"
+
+#define _COMPONENT          ACPI_NAMESPACE
+ACPI_MODULE_NAME("dspkginit")
+
+/* Local prototypes */
+static void
+acpi_ds_resolve_package_element(union acpi_operand_object **element);
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ds_build_internal_package_obj
+ *
+ * PARAMETERS:  walk_state      - Current walk state
+ *              op              - Parser object to be translated
+ *              element_count   - Number of elements in the package - this is
+ *                                the num_elements argument to Package()
+ *              obj_desc_ptr    - Where the ACPI internal object is returned
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Translate a parser Op package object to the equivalent
+ *              namespace object
+ *
+ * NOTE: The number of elements in the package will be always be the num_elements
+ * count, regardless of the number of elements in the package list. If
+ * num_elements is smaller, only that many package list elements are used.
+ * if num_elements is larger, the Package object is padded out with
+ * objects of type Uninitialized (as per ACPI spec.)
+ *
+ * Even though the ASL compilers do not allow num_elements to be smaller
+ * than the Package list length (for the fixed length package opcode), some
+ * BIOS code modifies the AML on the fly to adjust the num_elements, and
+ * this code compensates for that. This also provides compatibility with
+ * other AML interpreters.
+ *
+ ******************************************************************************/
+
+acpi_status
+acpi_ds_build_internal_package_obj(struct acpi_walk_state *walk_state,
+				   union acpi_parse_object *op,
+				   u32 element_count,
+				   union acpi_operand_object **obj_desc_ptr)
+{
+	union acpi_parse_object *arg;
+	union acpi_parse_object *parent;
+	union acpi_operand_object *obj_desc = NULL;
+	acpi_status status = AE_OK;
+	u16 reference_count;
+	u32 index;
+	u32 i;
+
+	ACPI_FUNCTION_TRACE(ds_build_internal_package_obj);
+
+	/* Find the parent of a possibly nested package */
+
+	parent = op->common.parent;
+	while ((parent->common.aml_opcode == AML_PACKAGE_OP) ||
+	       (parent->common.aml_opcode == AML_VARIABLE_PACKAGE_OP)) {
+		parent = parent->common.parent;
+	}
+
+	/*
+	 * If we are evaluating a Named package object of the form:
+	 *      Name (xxxx, Package)
+	 * the package object already exists, otherwise it must be created.
+	 */
+	obj_desc = *obj_desc_ptr;
+	if (!obj_desc) {
+		obj_desc = acpi_ut_create_internal_object(ACPI_TYPE_PACKAGE);
+		*obj_desc_ptr = obj_desc;
+		if (!obj_desc) {
+			return_ACPI_STATUS(AE_NO_MEMORY);
+		}
+
+		obj_desc->package.node = parent->common.node;
+	}
+
+	if (obj_desc->package.flags & AOPOBJ_DATA_VALID) {	/* Just in case */
+		return_ACPI_STATUS(AE_OK);
+	}
+
+	/*
+	 * Allocate the element array (array of pointers to the individual
+	 * objects) based on the num_elements parameter. Add an extra pointer slot
+	 * so that the list is always null terminated.
+	 */
+	obj_desc->package.elements = ACPI_ALLOCATE_ZEROED(((acpi_size)
+							   element_count +
+							   1) * sizeof(void *));
+
+	if (!obj_desc->package.elements) {
+		acpi_ut_delete_object_desc(obj_desc);
+		return_ACPI_STATUS(AE_NO_MEMORY);
+	}
+
+	obj_desc->package.count = element_count;
+	arg = op->common.value.arg;
+	arg = arg->common.next;
+
+	if (arg) {
+		obj_desc->package.flags |= AOPOBJ_DATA_VALID;
+	}
+
+	/*
+	 * Initialize the elements of the package, up to the num_elements count.
+	 * Package is automatically padded with uninitialized (NULL) elements
+	 * if num_elements is greater than the package list length. Likewise,
+	 * Package is truncated if num_elements is less than the list length.
+	 */
+	for (i = 0; arg && (i < element_count); i++) {
+		if (arg->common.aml_opcode == AML_INT_RETURN_VALUE_OP) {
+			if (arg->common.node->type == ACPI_TYPE_METHOD) {
+				/*
+				 * A method reference "looks" to the parser to be a method
+				 * invocation, so we special case it here
+				 */
+				arg->common.aml_opcode = AML_INT_NAMEPATH_OP;
+				status =
+				    acpi_ds_build_internal_object(walk_state,
+								  arg,
+								  &obj_desc->
+								  package.
+								  elements[i]);
+			} else {
+				/* This package element is already built, just get it */
+
+				obj_desc->package.elements[i] =
+				    ACPI_CAST_PTR(union acpi_operand_object,
+						  arg->common.node);
+			}
+		} else {
+			status =
+			    acpi_ds_build_internal_object(walk_state, arg,
+							  &obj_desc->package.
+							  elements[i]);
+			if (status == AE_NOT_FOUND) {
+				ACPI_ERROR((AE_INFO, "%-48s",
+					    "****DS namepath not found"));
+			}
+
+			/*
+			 * Initialize this package element. This function handles the
+			 * resolution of named references within the package.
+			 */
+			acpi_ds_init_package_element(0,
+						     obj_desc->package.
+						     elements[i], NULL,
+						     &obj_desc->package.
+						     elements[i]);
+		}
+
+		if (*obj_desc_ptr) {
+
+			/* Existing package, get existing reference count */
+
+			reference_count =
+			    (*obj_desc_ptr)->common.reference_count;
+			if (reference_count > 1) {
+
+				/* Make new element ref count match original ref count */
+				/* TBD: Probably need an acpi_ut_add_references function */
+
+				for (index = 0;
+				     index < ((u32)reference_count - 1);
+				     index++) {
+					acpi_ut_add_reference((obj_desc->
+							       package.
+							       elements[i]));
+				}
+			}
+		}
+
+		arg = arg->common.next;
+	}
+
+	/* Check for match between num_elements and actual length of package_list */
+
+	if (arg) {
+		/*
+		 * num_elements was exhausted, but there are remaining elements in
+		 * the package_list. Truncate the package to num_elements.
+		 *
+		 * Note: technically, this is an error, from ACPI spec: "It is an
+		 * error for NumElements to be less than the number of elements in
+		 * the PackageList". However, we just print a message and no
+		 * exception is returned. This provides compatibility with other
+		 * ACPI implementations. Some firmware implementations will alter
+		 * the num_elements on the fly, possibly creating this type of
+		 * ill-formed package object.
+		 */
+		while (arg) {
+			/*
+			 * We must delete any package elements that were created earlier
+			 * and are not going to be used because of the package truncation.
+			 */
+			if (arg->common.node) {
+				acpi_ut_remove_reference(ACPI_CAST_PTR
+							 (union
+							  acpi_operand_object,
+							  arg->common.node));
+				arg->common.node = NULL;
+			}
+
+			/* Find out how many elements there really are */
+
+			i++;
+			arg = arg->common.next;
+		}
+
+		ACPI_INFO(("Actual Package length (%u) is larger than "
+			   "NumElements field (%u), truncated",
+			   i, element_count));
+	} else if (i < element_count) {
+		/*
+		 * Arg list (elements) was exhausted, but we did not reach
+		 * num_elements count.
+		 *
+		 * Note: this is not an error, the package is padded out
+		 * with NULLs.
+		 */
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+				  "Package List length (%u) smaller than NumElements "
+				  "count (%u), padded with null elements\n",
+				  i, element_count));
+	}
+
+	obj_desc->package.flags |= AOPOBJ_DATA_VALID;
+	op->common.node = ACPI_CAST_PTR(struct acpi_namespace_node, obj_desc);
+	return_ACPI_STATUS(status);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ds_init_package_element
+ *
+ * PARAMETERS:  acpi_pkg_callback
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Resolve a named reference element within a package object
+ *
+ ******************************************************************************/
+
+acpi_status
+acpi_ds_init_package_element(u8 object_type,
+			     union acpi_operand_object *source_object,
+			     union acpi_generic_state *state, void *context)
+{
+	union acpi_operand_object **element_ptr;
+
+	if (!source_object) {
+		return (AE_OK);
+	}
+
+	/*
+	 * The following code is a bit of a hack to workaround a (current)
+	 * limitation of the acpi_pkg_callback interface. We need a pointer
+	 * to the location within the element array because a new object
+	 * may be created and stored there.
+	 */
+	if (context) {
+
+		/* A direct call was made to this function */
+
+		element_ptr = (union acpi_operand_object **)context;
+	} else {
+		/* Call came from acpi_ut_walk_package_tree */
+
+		element_ptr = state->pkg.this_target_obj;
+	}
+
+	/* We are only interested in reference objects/elements */
+
+	if (source_object->common.type == ACPI_TYPE_LOCAL_REFERENCE) {
+
+		/* Attempt to resolve the (named) reference to a namespace node */
+
+		acpi_ds_resolve_package_element(element_ptr);
+	} else if (source_object->common.type == ACPI_TYPE_PACKAGE) {
+		source_object->package.flags |= AOPOBJ_DATA_VALID;
+	}
+
+	return (AE_OK);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ds_resolve_package_element
+ *
+ * PARAMETERS:  element_ptr         - Pointer to a reference object
+ *
+ * RETURN:      Possible new element is stored to the indirect element_ptr
+ *
+ * DESCRIPTION: Resolve a package element that is a reference to a named
+ *              object.
+ *
+ ******************************************************************************/
+
+static void
+acpi_ds_resolve_package_element(union acpi_operand_object **element_ptr)
+{
+	acpi_status status;
+	union acpi_generic_state scope_info;
+	union acpi_operand_object *element = *element_ptr;
+	struct acpi_namespace_node *resolved_node;
+	char *external_path = NULL;
+	acpi_object_type type;
+
+	ACPI_FUNCTION_TRACE(ds_resolve_package_element);
+
+	/* Check if reference element is already resolved */
+
+	if (element->reference.resolved) {
+		return_VOID;
+	}
+
+	/* Element must be a reference object of correct type */
+
+	scope_info.scope.node = element->reference.node;	/* Prefix node */
+
+	status = acpi_ns_lookup(&scope_info, (char *)element->reference.aml,	/* Pointer to AML path */
+				ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE,
+				ACPI_NS_SEARCH_PARENT | ACPI_NS_DONT_OPEN_SCOPE,
+				NULL, &resolved_node);
+	if (ACPI_FAILURE(status)) {
+		status = acpi_ns_externalize_name(ACPI_UINT32_MAX,
+						  (char *)element->reference.
+						  aml, NULL, &external_path);
+
+		ACPI_EXCEPTION((AE_INFO, status,
+				"Could not find/resolve named package element: %s",
+				external_path));
+
+		ACPI_FREE(external_path);
+		*element_ptr = NULL;
+		return_VOID;
+	} else if (resolved_node->type == ACPI_TYPE_ANY) {
+
+		/* Named reference not resolved, return a NULL package element */
+
+		ACPI_ERROR((AE_INFO,
+			    "Could not resolve named package element [%4.4s] in [%4.4s]",
+			    resolved_node->name.ascii,
+			    scope_info.scope.node->name.ascii));
+		*element_ptr = NULL;
+		return_VOID;
+	}
+#if 0
+	else if (resolved_node->flags & ANOBJ_TEMPORARY) {
+		/*
+		 * A temporary node found here indicates that the reference is
+		 * to a node that was created within this method. We are not
+		 * going to allow it (especially if the package is returned
+		 * from the method) -- the temporary node will be deleted out
+		 * from under the method. (05/2017).
+		 */
+		ACPI_ERROR((AE_INFO,
+			    "Package element refers to a temporary name [%4.4s], "
+			    "inserting a NULL element",
+			    resolved_node->name.ascii));
+		*element_ptr = NULL;
+		return_VOID;
+	}
+#endif
+
+	/*
+	 * Special handling for Alias objects. We need resolved_node to point
+	 * to the Alias target. This effectively "resolves" the alias.
+	 */
+	if (resolved_node->type == ACPI_TYPE_LOCAL_ALIAS) {
+		resolved_node = ACPI_CAST_PTR(struct acpi_namespace_node,
+					      resolved_node->object);
+	}
+
+	/* Update the reference object */
+
+	element->reference.resolved = TRUE;
+	element->reference.node = resolved_node;
+	type = element->reference.node->type;
+
+	/*
+	 * Attempt to resolve the node to a value before we insert it into
+	 * the package. If this is a reference to a common data type,
+	 * resolve it immediately. According to the ACPI spec, package
+	 * elements can only be "data objects" or method references.
+	 * Attempt to resolve to an Integer, Buffer, String or Package.
+	 * If cannot, return the named reference (for things like Devices,
+	 * Methods, etc.) Buffer Fields and Fields will resolve to simple
+	 * objects (int/buf/str/pkg).
+	 *
+	 * NOTE: References to things like Devices, Methods, Mutexes, etc.
+	 * will remain as named references. This behavior is not described
+	 * in the ACPI spec, but it appears to be an oversight.
+	 */
+	status = acpi_ex_resolve_node_to_value(&resolved_node, NULL);
+	if (ACPI_FAILURE(status)) {
+		return_VOID;
+	}
+#if 0
+/* TBD - alias support */
+	/*
+	 * Special handling for Alias objects. We need to setup the type
+	 * and the Op->Common.Node to point to the Alias target. Note,
+	 * Alias has at most one level of indirection internally.
+	 */
+	type = op->common.node->type;
+	if (type == ACPI_TYPE_LOCAL_ALIAS) {
+		type = obj_desc->common.type;
+		op->common.node = ACPI_CAST_PTR(struct acpi_namespace_node,
+						op->common.node->object);
+	}
+#endif
+
+	switch (type) {
+		/*
+		 * These object types are a result of named references, so we will
+		 * leave them as reference objects. In other words, these types
+		 * have no intrinsic "value".
+		 */
+	case ACPI_TYPE_DEVICE:
+	case ACPI_TYPE_THERMAL:
+
+		/* TBD: This may not be necesssary */
+
+		acpi_ut_add_reference(resolved_node->object);
+		break;
+
+	case ACPI_TYPE_MUTEX:
+	case ACPI_TYPE_METHOD:
+	case ACPI_TYPE_POWER:
+	case ACPI_TYPE_PROCESSOR:
+	case ACPI_TYPE_EVENT:
+	case ACPI_TYPE_REGION:
+
+		break;
+
+	default:
+		/*
+		 * For all other types - the node was resolved to an actual
+		 * operand object with a value, return the object
+		 */
+		*element_ptr = (union acpi_operand_object *)resolved_node;
+		break;
+	}
+
+	return_VOID;
+}