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/*******************************************************************************

 *

 * Module Name: nsaccess - Top-level functions for accessing ACPI namespace

 *

 ******************************************************************************/

/*

 * Copyright (C) 2000 - 2015, 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 

#include "accommon.h"

#include "amlcode.h"

#include "acnamesp.h"

#include "acdispat.h"

#define _COMPONENT          ACPI_NAMESPACE

ACPI_MODULE_NAME("nsaccess")

/*******************************************************************************

 *

 * FUNCTION:    acpi_ns_root_initialize

 *

 * PARAMETERS:  None

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Allocate and initialize the default root named objects

 *

 * MUTEX:       Locks namespace for entire execution

 *

 ******************************************************************************/

acpi_status acpi_ns_root_initialize(void)

{

	acpi_status status;

	const struct acpi_predefined_names *init_val = NULL;

	struct acpi_namespace_node *new_node;

	union acpi_operand_object *obj_desc;

	acpi_string val = NULL;

	ACPI_FUNCTION_TRACE(ns_root_initialize);

	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);

	if (ACPI_FAILURE(status)) {

		return_ACPI_STATUS(status);

	}

	/*

	 * The global root ptr is initially NULL, so a non-NULL value indicates

	 * that acpi_ns_root_initialize() has already been called; just return.

	 */

	if (acpi_gbl_root_node) {

		status = AE_OK;

		goto unlock_and_exit;

	}

	/*

	 * Tell the rest of the subsystem that the root is initialized

	 * (This is OK because the namespace is locked)

	 */

	acpi_gbl_root_node = &acpi_gbl_root_node_struct;

	/* Enter the pre-defined names in the name table */

	ACPI_DEBUG_PRINT((ACPI_DB_INFO,

			  "Entering predefined entries into namespace\n"));

	for (init_val = acpi_gbl_pre_defined_names; init_val->name; init_val++) {

		/* _OSI is optional for now, will be permanent later */

		if (!strcmp(init_val->name, "_OSI")

		    && !acpi_gbl_create_osi_method) {

			continue;

		}

		status = acpi_ns_lookup(NULL, init_val->name, init_val->type,

					ACPI_IMODE_LOAD_PASS2,

					ACPI_NS_NO_UPSEARCH, NULL, &new_node);

		if (ACPI_FAILURE(status)) {

			ACPI_EXCEPTION((AE_INFO, status,

					"Could not create predefined name %s",

					init_val->name));

			continue;

		}

		/*

		 * Name entered successfully. If entry in pre_defined_names[] specifies

		 * an initial value, create the initial value.

		 */

		if (init_val->val) {

			status = acpi_os_predefined_override(init_val, &val);

			if (ACPI_FAILURE(status)) {

				ACPI_ERROR((AE_INFO,

					    "Could not override predefined %s",

					    init_val->name));

			}

			if (!val) {

				val = init_val->val;

			}

			/*

			 * Entry requests an initial value, allocate a

			 * descriptor for it.

			 */

			obj_desc =

			    acpi_ut_create_internal_object(init_val->type);

			if (!obj_desc) {

				status = AE_NO_MEMORY;

				goto unlock_and_exit;

			}

			/*

			 * Convert value string from table entry to

			 * internal representation. Only types actually

			 * used for initial values are implemented here.

			 */

			switch (init_val->type) {

			case ACPI_TYPE_METHOD:

				obj_desc->method.param_count =

				    (u8) ACPI_TO_INTEGER(val);

				obj_desc->common.flags |= AOPOBJ_DATA_VALID;

#if defined (ACPI_ASL_COMPILER)

				/* Save the parameter count for the iASL compiler */

				new_node->value = obj_desc->method.param_count;

#else

				/* Mark this as a very SPECIAL method */

				obj_desc->method.info_flags =

				    ACPI_METHOD_INTERNAL_ONLY;

				obj_desc->method.dispatch.implementation =

				    acpi_ut_osi_implementation;

#endif

				break;

			case ACPI_TYPE_INTEGER:

				obj_desc->integer.value = ACPI_TO_INTEGER(val);

				break;

			case ACPI_TYPE_STRING:

				/* Build an object around the static string */

				obj_desc->string.length = (u32)strlen(val);

				obj_desc->string.pointer = val;

				obj_desc->common.flags |= AOPOBJ_STATIC_POINTER;

				break;

			case ACPI_TYPE_MUTEX:

				obj_desc->mutex.node = new_node;

				obj_desc->mutex.sync_level =

				    (u8) (ACPI_TO_INTEGER(val) - 1);

				/* Create a mutex */

				status =

				    acpi_os_create_mutex(&obj_desc->mutex.

							 os_mutex);

				if (ACPI_FAILURE(status)) {

					acpi_ut_remove_reference(obj_desc);

					goto unlock_and_exit;

				}

				/* Special case for ACPI Global Lock */

				if (strcmp(init_val->name, "_GL_") == 0) {

					acpi_gbl_global_lock_mutex = obj_desc;

					/* Create additional counting semaphore for global lock */

					status =

					    acpi_os_create_semaphore(1, 0,

								     &acpi_gbl_global_lock_semaphore);

					if (ACPI_FAILURE(status)) {

						acpi_ut_remove_reference

						    (obj_desc);

						goto unlock_and_exit;

					}

				}

				break;

			default:

				ACPI_ERROR((AE_INFO,

					    "Unsupported initial type value 0x%X",

					    init_val->type));

				acpi_ut_remove_reference(obj_desc);

				obj_desc = NULL;

				continue;

			}

			/* Store pointer to value descriptor in the Node */

			status = acpi_ns_attach_object(new_node, obj_desc,

						       obj_desc->common.type);

			/* Remove local reference to the object */

			acpi_ut_remove_reference(obj_desc);

		}

	}

unlock_and_exit:

	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);

	/* Save a handle to "_GPE", it is always present */

	if (ACPI_SUCCESS(status)) {

		status = acpi_ns_get_node(NULL, "\\_GPE", ACPI_NS_NO_UPSEARCH,

					  &acpi_gbl_fadt_gpe_device);

	}

	return_ACPI_STATUS(status);

}

/*******************************************************************************

 *

 * FUNCTION:    acpi_ns_lookup

 *

 * PARAMETERS:  scope_info      - Current scope info block

 *              pathname        - Search pathname, in internal format

 *                                (as represented in the AML stream)

 *              type            - Type associated with name

 *              interpreter_mode - IMODE_LOAD_PASS2 => add name if not found

 *              flags           - Flags describing the search restrictions

 *              walk_state      - Current state of the walk

 *              return_node     - Where the Node is placed (if found

 *                                or created successfully)

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Find or enter the passed name in the name space.

 *              Log an error if name not found in Exec mode.

 *

 * MUTEX:       Assumes namespace is locked.

 *

 ******************************************************************************/

acpi_status

acpi_ns_lookup(union acpi_generic_state *scope_info,

	       char *pathname,

	       acpi_object_type type,

	       acpi_interpreter_mode interpreter_mode,

	       u32 flags,

	       struct acpi_walk_state *walk_state,

	       struct acpi_namespace_node **return_node)

{

	acpi_status status;

	char *path = pathname;

	struct acpi_namespace_node *prefix_node;

	struct acpi_namespace_node *current_node = NULL;

	struct acpi_namespace_node *this_node = NULL;

	u32 num_segments;

	u32 num_carats;

	acpi_name simple_name;

	acpi_object_type type_to_check_for;

	acpi_object_type this_search_type;

	u32 search_parent_flag = ACPI_NS_SEARCH_PARENT;

	u32 local_flags;

	ACPI_FUNCTION_TRACE(ns_lookup);

	if (!return_node) {

		return_ACPI_STATUS(AE_BAD_PARAMETER);

	}

	local_flags = flags &

	    ~(ACPI_NS_ERROR_IF_FOUND | ACPI_NS_OVERRIDE_IF_FOUND |

	      ACPI_NS_SEARCH_PARENT);

	*return_node = ACPI_ENTRY_NOT_FOUND;

	acpi_gbl_ns_lookup_count++;

	if (!acpi_gbl_root_node) {

		return_ACPI_STATUS(AE_NO_NAMESPACE);

	}

	/* Get the prefix scope. A null scope means use the root scope */

	if ((!scope_info) || (!scope_info->scope.node)) {

		ACPI_DEBUG_PRINT((ACPI_DB_NAMES,

				  "Null scope prefix, using root node (%p)\n",

				  acpi_gbl_root_node));

		prefix_node = acpi_gbl_root_node;

	} else {

		prefix_node = scope_info->scope.node;

		if (ACPI_GET_DESCRIPTOR_TYPE(prefix_node) !=

		    ACPI_DESC_TYPE_NAMED) {

			ACPI_ERROR((AE_INFO, "%p is not a namespace node [%s]",

				    prefix_node,

				    acpi_ut_get_descriptor_name(prefix_node)));

			return_ACPI_STATUS(AE_AML_INTERNAL);

		}

		if (!(flags & ACPI_NS_PREFIX_IS_SCOPE)) {

			/*

			 * This node might not be a actual "scope" node (such as a

			 * Device/Method, etc.)  It could be a Package or other object

			 * node. Backup up the tree to find the containing scope node.

			 */

			while (!acpi_ns_opens_scope(prefix_node->type) &&

			       prefix_node->type != ACPI_TYPE_ANY) {

				prefix_node = prefix_node->parent;

			}

		}

	}

	/* Save type. TBD: may be no longer necessary */

	type_to_check_for = type;

	/*

	 * Begin examination of the actual pathname

	 */

	if (!pathname) {

		/* A Null name_path is allowed and refers to the root */

		num_segments = 0;

		this_node = acpi_gbl_root_node;

		path = "";

		ACPI_DEBUG_PRINT((ACPI_DB_NAMES,

				  "Null Pathname (Zero segments), Flags=%X\n",

				  flags));

	} else {

		/*

		 * Name pointer is valid (and must be in internal name format)

		 *

		 * Check for scope prefixes:

		 *

		 * As represented in the AML stream, a namepath consists of an

		 * optional scope prefix followed by a name segment part.

		 *

		 * If present, the scope prefix is either a Root Prefix (in

		 * which case the name is fully qualified), or one or more

		 * Parent Prefixes (in which case the name's scope is relative

		 * to the current scope).

		 */

		if (*path == (u8) AML_ROOT_PREFIX) {

			/* Pathname is fully qualified, start from the root */

			this_node = acpi_gbl_root_node;

			search_parent_flag = ACPI_NS_NO_UPSEARCH;

			/* Point to name segment part */

			path++;

			ACPI_DEBUG_PRINT((ACPI_DB_NAMES,

					  "Path is absolute from root [%p]\n",

					  this_node));

		} else {

			/* Pathname is relative to current scope, start there */

			ACPI_DEBUG_PRINT((ACPI_DB_NAMES,

					  "Searching relative to prefix scope [%4.4s] (%p)\n",

					  acpi_ut_get_node_name(prefix_node),

					  prefix_node));

			/*

			 * Handle multiple Parent Prefixes (carat) by just getting

			 * the parent node for each prefix instance.

			 */

			this_node = prefix_node;

			num_carats = 0;

			while (*path == (u8) AML_PARENT_PREFIX) {

				/* Name is fully qualified, no search rules apply */

				search_parent_flag = ACPI_NS_NO_UPSEARCH;

				/*

				 * Point past this prefix to the name segment

				 * part or the next Parent Prefix

				 */

				path++;

				/* Backup to the parent node */

				num_carats++;

				this_node = this_node->parent;

				if (!this_node) {

					/* Current scope has no parent scope */

					ACPI_ERROR((AE_INFO,

						    "%s: Path has too many parent prefixes (^) "

						    "- reached beyond root node",

						    pathname));

					return_ACPI_STATUS(AE_NOT_FOUND);

				}

			}

			if (search_parent_flag == ACPI_NS_NO_UPSEARCH) {

				ACPI_DEBUG_PRINT((ACPI_DB_NAMES,

						  "Search scope is [%4.4s], path has %u carat(s)\n",

						  acpi_ut_get_node_name

						  (this_node), num_carats));

			}

		}

		/*

		 * Determine the number of ACPI name segments in this pathname.

		 *

		 * The segment part consists of either:

		 *  - A Null name segment (0)

		 *  - A dual_name_prefix followed by two 4-byte name segments

		 *  - A multi_name_prefix followed by a byte indicating the

		 *      number of segments and the segments themselves.

		 *  - A single 4-byte name segment

		 *

		 * Examine the name prefix opcode, if any, to determine the number of

		 * segments.

		 */

		switch (*path) {

		case 0:

			/*

			 * Null name after a root or parent prefixes. We already

			 * have the correct target node and there are no name segments.

			 */

			num_segments = 0;

			type = this_node->type;

			ACPI_DEBUG_PRINT((ACPI_DB_NAMES,

					  "Prefix-only Pathname (Zero name segments), Flags=%X\n",

					  flags));

			break;

		case AML_DUAL_NAME_PREFIX:

			/* More than one name_seg, search rules do not apply */

			search_parent_flag = ACPI_NS_NO_UPSEARCH;

			/* Two segments, point to first name segment */

			num_segments = 2;

			path++;

			ACPI_DEBUG_PRINT((ACPI_DB_NAMES,

					  "Dual Pathname (2 segments, Flags=%X)\n",

					  flags));

			break;

		case AML_MULTI_NAME_PREFIX_OP:

			/* More than one name_seg, search rules do not apply */

			search_parent_flag = ACPI_NS_NO_UPSEARCH;

			/* Extract segment count, point to first name segment */

			path++;

			num_segments = (u32) (u8) * path;

			path++;

			ACPI_DEBUG_PRINT((ACPI_DB_NAMES,

					  "Multi Pathname (%u Segments, Flags=%X)\n",

					  num_segments, flags));

			break;

		default:

			/*

			 * Not a Null name, no Dual or Multi prefix, hence there is

			 * only one name segment and Pathname is already pointing to it.

			 */

			num_segments = 1;

			ACPI_DEBUG_PRINT((ACPI_DB_NAMES,

					  "Simple Pathname (1 segment, Flags=%X)\n",

					  flags));

			break;

		}

		ACPI_DEBUG_EXEC(acpi_ns_print_pathname(num_segments, path));

	}

	/*

	 * Search namespace for each segment of the name. Loop through and

	 * verify (or add to the namespace) each name segment.

	 *

	 * The object type is significant only at the last name

	 * segment. (We don't care about the types along the path, only

	 * the type of the final target object.)

	 */

	this_search_type = ACPI_TYPE_ANY;

	current_node = this_node;

	while (num_segments && current_node) {

		num_segments--;

		if (!num_segments) {

			/* This is the last segment, enable typechecking */

			this_search_type = type;

			/*

			 * Only allow automatic parent search (search rules) if the caller

			 * requested it AND we have a single, non-fully-qualified name_seg

			 */

			if ((search_parent_flag != ACPI_NS_NO_UPSEARCH) &&

			    (flags & ACPI_NS_SEARCH_PARENT)) {

				local_flags |= ACPI_NS_SEARCH_PARENT;

			}

			/* Set error flag according to caller */

			if (flags & ACPI_NS_ERROR_IF_FOUND) {

				local_flags |= ACPI_NS_ERROR_IF_FOUND;

			}

			/* Set override flag according to caller */

			if (flags & ACPI_NS_OVERRIDE_IF_FOUND) {

				local_flags |= ACPI_NS_OVERRIDE_IF_FOUND;

			}

		}

		/* Extract one ACPI name from the front of the pathname */

		ACPI_MOVE_32_TO_32(&simple_name, path);

		/* Try to find the single (4 character) ACPI name */

		status =

		    acpi_ns_search_and_enter(simple_name, walk_state,

					     current_node, interpreter_mode,

					     this_search_type, local_flags,

					     &this_node);

		if (ACPI_FAILURE(status)) {

			if (status == AE_NOT_FOUND) {

				/* Name not found in ACPI namespace */

				ACPI_DEBUG_PRINT((ACPI_DB_NAMES,

						  "Name [%4.4s] not found in scope [%4.4s] %p\n",

						  (char *)&simple_name,

						  (char *)¤t_node->name,

						  current_node));

			}

			*return_node = this_node;

			return_ACPI_STATUS(status);

		}

		/* More segments to follow? */

		if (num_segments > 0) {

			/*

			 * If we have an alias to an object that opens a scope (such as a

			 * device or processor), we need to dereference the alias here so

			 * that we can access any children of the original node (via the

			 * remaining segments).

			 */

			if (this_node->type == ACPI_TYPE_LOCAL_ALIAS) {

				if (!this_node->object) {

					return_ACPI_STATUS(AE_NOT_EXIST);

				}

				if (acpi_ns_opens_scope

				    (((struct acpi_namespace_node *)

				      this_node->object)->type)) {

					this_node =

					    (struct acpi_namespace_node *)

					    this_node->object;

				}

			}

		}

		/* Special handling for the last segment (num_segments == 0) */

		else {

			/*

			 * Sanity typecheck of the target object:

			 *

			 * If 1) This is the last segment (num_segments == 0)

			 *    2) And we are looking for a specific type

			 *       (Not checking for TYPE_ANY)

			 *    3) Which is not an alias

			 *    4) Which is not a local type (TYPE_SCOPE)

			 *    5) And the type of target object is known (not TYPE_ANY)

			 *    6) And target object does not match what we are looking for

			 *

			 * Then we have a type mismatch. Just warn and ignore it.

			 */

			if ((type_to_check_for != ACPI_TYPE_ANY) &&

			    (type_to_check_for != ACPI_TYPE_LOCAL_ALIAS) &&

			    (type_to_check_for != ACPI_TYPE_LOCAL_METHOD_ALIAS)

			    && (type_to_check_for != ACPI_TYPE_LOCAL_SCOPE)

			    && (this_node->type != ACPI_TYPE_ANY)

			    && (this_node->type != type_to_check_for)) {

				/* Complain about a type mismatch */

				ACPI_WARNING((AE_INFO,

					      "NsLookup: Type mismatch on %4.4s (%s), searching for (%s)",

					      ACPI_CAST_PTR(char, &simple_name),

					      acpi_ut_get_type_name(this_node->

								    type),

					      acpi_ut_get_type_name

					      (type_to_check_for)));

			}

			/*

			 * If this is the last name segment and we are not looking for a

			 * specific type, but the type of found object is known, use that

			 * type to (later) see if it opens a scope.

			 */

			if (type == ACPI_TYPE_ANY) {

				type = this_node->type;

			}

		}

		/* Point to next name segment and make this node current */

		path += ACPI_NAME_SIZE;

		current_node = this_node;

	}

	/* Always check if we need to open a new scope */

	if (!(flags & ACPI_NS_DONT_OPEN_SCOPE) && (walk_state)) {

		/*

		 * If entry is a type which opens a scope, push the new scope on the

		 * scope stack.

		 */

		if (acpi_ns_opens_scope(type)) {

			status =

			    acpi_ds_scope_stack_push(this_node, type,

						     walk_state);

			if (ACPI_FAILURE(status)) {

				return_ACPI_STATUS(status);

			}

		}

	}

	*return_node = this_node;

	return_ACPI_STATUS(AE_OK);

}