patch-2.4.0-test3 linux/drivers/acpi/namespace/nswalk.c

• Lines: 280
• Date: Wed Jul 5 11:23:12 2000
• Orig file: v2.4.0-test2/linux/drivers/acpi/namespace/nswalk.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.0-test2/linux/drivers/acpi/namespace/nswalk.c linux/drivers/acpi/namespace/nswalk.c
@@ -0,0 +1,279 @@
+
+/******************************************************************************
+ *
+ * Module Name: nswalk - Functions for walking the APCI namespace
+ *
+ *****************************************************************************/
+
+/*
+ *  Copyright (C) 2000 R. Byron Moore
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+
+#include "acpi.h"
+#include "interp.h"
+#include "namesp.h"
+
+
+#define _COMPONENT          NAMESPACE
+	 MODULE_NAME         ("nswalk");
+
+
+/****************************************************************************
+ *
+ * FUNCTION:    Acpi_get_next_object
+ *
+ * PARAMETERS:  Type            - Type of object to be searched for
+ *              Parent          - Parent object whose children we are getting
+ *              Last_child      - Previous child that was found.
+ *                                The NEXT child will be returned
+ *              Ret_handle      - Where handle to the next object is placed
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Return the next peer object within the namespace.  If Handle is
+ *              valid, Scope is ignored.  Otherwise, the first object within
+ *              Scope is returned.
+ *
+ ******************************************************************************/
+
+ACPI_NAMED_OBJECT*
+acpi_ns_get_next_object (
+	OBJECT_TYPE_INTERNAL    type,
+	ACPI_NAMED_OBJECT       *parent,
+	ACPI_NAMED_OBJECT       *child)
+{
+	ACPI_NAMED_OBJECT       *this_entry = NULL;
+
+
+	if (!child) {
+
+		/* It's really the parent's _scope_ that we want */
+
+		if (parent->child_table) {
+			this_entry = parent->child_table->entries;
+		}
+	}
+
+	else {
+		/* Start search at the NEXT object */
+
+		this_entry = acpi_ns_get_next_valid_entry (child);
+	}
+
+
+	/* If any type is OK, we are done */
+
+	if (type == ACPI_TYPE_ANY) {
+		/* Make sure this is valid entry first */
+
+		if ((!this_entry) ||
+			(!this_entry->name))
+		{
+			return NULL;
+		}
+
+		return (this_entry);
+	}
+
+
+	/* Must search for the object -- but within this scope only */
+
+	while (this_entry) {
+		/* If type matches, we are done */
+
+		if (this_entry->type == type) {
+			return (this_entry);
+		}
+
+		/* Otherwise, move on to the next object */
+
+		this_entry = acpi_ns_get_next_valid_entry (this_entry);
+	}
+
+
+	/* Not found */
+
+	return NULL;
+}
+
+
+/******************************************************************************
+ *
+ * FUNCTION:    Acpi_ns_walk_namespace
+ *
+ * PARAMETERS:  Type                - ACPI_OBJECT_TYPE to search for
+ *              Start_object        - Handle in namespace where search begins
+ *              Max_depth           - Depth to which search is to reach
+ *              Unlock_before_callback- Whether to unlock the NS before invoking
+ *                                    the callback routine
+ *              User_function       - Called when an object of "Type" is found
+ *              Context             - Passed to user function
+ *
+ * RETURNS      Return value from the User_function if terminated early.
+ *              Otherwise, returns NULL.
+ *
+ * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
+ *              starting (and ending) at the object specified by Start_handle.
+ *              The User_function is called whenever an object that matches
+ *              the type parameter is found.  If the user function returns
+ *              a non-zero value, the search is terminated immediately and this
+ *              value is returned to the caller.
+ *
+ *              The point of this procedure is to provide a generic namespace
+ *              walk routine that can be called from multiple places to
+ *              provide multiple services;  the User Function can be tailored
+ *              to each task, whether it is a print function, a compare
+ *              function, etc.
+ *
+ ******************************************************************************/
+
+ACPI_STATUS
+acpi_ns_walk_namespace (
+	OBJECT_TYPE_INTERNAL    type,
+	ACPI_HANDLE             start_object,
+	u32                     max_depth,
+	u8                      unlock_before_callback,
+	WALK_CALLBACK           user_function,
+	void                    *context,
+	void                    **return_value)
+{
+	ACPI_STATUS             status;
+	ACPI_NAMED_OBJECT       *child_entry;
+	ACPI_NAMED_OBJECT       *parent_entry;
+	OBJECT_TYPE_INTERNAL    child_type;
+	u32                     level;
+
+
+	/* Special case for the namespace root object */
+
+	if (start_object == ACPI_ROOT_OBJECT) {
+		start_object = acpi_gbl_root_object;
+	}
+
+
+	/* Null child means "get first object" */
+
+	parent_entry   = start_object;
+	child_entry    = 0;
+	child_type      = ACPI_TYPE_ANY;
+	level           = 1;
+
+	/*
+	 * Traverse the tree of objects until we bubble back up to where we
+	 * started. When Level is zero, the loop is done because we have
+	 * bubbled up to (and passed) the original parent handle (Start_entry)
+	 */
+
+	while (level > 0) {
+		/*
+		 * Get the next typed object in this scope.  Null returned
+		 * if not found
+		 */
+
+		status = AE_OK;
+		child_entry = acpi_ns_get_next_object (ACPI_TYPE_ANY,
+				 parent_entry,
+				 child_entry);
+
+		if (child_entry) {
+			/*
+			 * Found an object, Get the type if we are not
+			 * searching for ANY
+			 */
+
+			if (type != ACPI_TYPE_ANY) {
+				child_type = child_entry->type;
+			}
+
+			if (child_type == type) {
+				/*
+				 * Found a matching object, invoke the user
+				 * callback function
+				 */
+
+				if (unlock_before_callback) {
+					acpi_cm_release_mutex (ACPI_MTX_NAMESPACE);
+				}
+
+				status = user_function (child_entry, level,
+						 context, return_value);
+
+				if (unlock_before_callback) {
+					acpi_cm_acquire_mutex (ACPI_MTX_NAMESPACE);
+				}
+
+				switch (status)
+				{
+				case AE_OK:
+				case AE_CTRL_DEPTH:
+					/* Just keep going */
+					break;
+
+				case AE_CTRL_TERMINATE:
+					/* Exit now, with OK status */
+					return (AE_OK);
+					break;
+
+				default:
+					/* All others are valid exceptions */
+					return (status);
+					break;
+				}
+			}
+
+			/*
+			 * Depth first search:
+			 * Attempt to go down another level in the namespace
+			 * if we are allowed to.  Don't go any further if we
+			 * have reached the caller specified maximum depth
+			 * or if the user function has specified that the
+			 * maximum depth has been reached.
+			 */
+
+			if ((level < max_depth) && (status != AE_CTRL_DEPTH)) {
+				if (acpi_ns_get_next_object (ACPI_TYPE_ANY,
+						 child_entry, 0))
+				{
+					/*
+					 * There is at least one child of this
+					 * object, visit the object
+					 */
+					level++;
+					parent_entry   = child_entry;
+					child_entry    = 0;
+				}
+			}
+		}
+
+		else {
+			/*
+			 * No more children in this object (Acpi_ns_get_next_object
+			 * failed), go back upwards in the namespace tree to
+			 * the object's parent.
+			 */
+			level--;
+			child_entry = parent_entry;
+			parent_entry = acpi_ns_get_parent_entry (parent_entry);
+		}
+	}
+
+	/* Complete walk, not terminated by user function */
+	return (AE_OK);
+}
+
+