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-rw-r--r--drivers/acpi/acpica/nswalk.c327
1 files changed, 327 insertions, 0 deletions
diff --git a/drivers/acpi/acpica/nswalk.c b/drivers/acpi/acpica/nswalk.c
new file mode 100644
index 000000000..901fa5ca2
--- /dev/null
+++ b/drivers/acpi/acpica/nswalk.c
@@ -0,0 +1,327 @@
+// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
+/******************************************************************************
+ *
+ * Module Name: nswalk - Functions for walking the ACPI namespace
+ *
+ * Copyright (C) 2000 - 2020, Intel Corp.
+ *
+ *****************************************************************************/
+
+#include <acpi/acpi.h>
+#include "accommon.h"
+#include "acnamesp.h"
+
+#define _COMPONENT ACPI_NAMESPACE
+ACPI_MODULE_NAME("nswalk")
+
+/*******************************************************************************
+ *
+ * FUNCTION: acpi_ns_get_next_node
+ *
+ * PARAMETERS: parent_node - Parent node whose children we are
+ * getting
+ * child_node - Previous child that was found.
+ * The NEXT child will be returned
+ *
+ * RETURN: struct acpi_namespace_node - Pointer to the NEXT child or NULL if
+ * none is found.
+ *
+ * DESCRIPTION: Return the next peer node within the namespace. If Handle
+ * is valid, Scope is ignored. Otherwise, the first node
+ * within Scope is returned.
+ *
+ ******************************************************************************/
+struct acpi_namespace_node *acpi_ns_get_next_node(struct acpi_namespace_node
+ *parent_node,
+ struct acpi_namespace_node
+ *child_node)
+{
+ ACPI_FUNCTION_ENTRY();
+
+ if (!child_node) {
+
+ /* It's really the parent's _scope_ that we want */
+
+ return (parent_node->child);
+ }
+
+ /* Otherwise just return the next peer */
+
+ return (child_node->peer);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION: acpi_ns_get_next_node_typed
+ *
+ * PARAMETERS: type - Type of node to be searched for
+ * parent_node - Parent node whose children we are
+ * getting
+ * child_node - Previous child that was found.
+ * The NEXT child will be returned
+ *
+ * RETURN: struct acpi_namespace_node - Pointer to the NEXT child or NULL if
+ * none is found.
+ *
+ * DESCRIPTION: Return the next peer node within the namespace. If Handle
+ * is valid, Scope is ignored. Otherwise, the first node
+ * within Scope is returned.
+ *
+ ******************************************************************************/
+
+struct acpi_namespace_node *acpi_ns_get_next_node_typed(acpi_object_type type,
+ struct
+ acpi_namespace_node
+ *parent_node,
+ struct
+ acpi_namespace_node
+ *child_node)
+{
+ struct acpi_namespace_node *next_node = NULL;
+
+ ACPI_FUNCTION_ENTRY();
+
+ next_node = acpi_ns_get_next_node(parent_node, child_node);
+
+
+ /* If any type is OK, we are done */
+
+ if (type == ACPI_TYPE_ANY) {
+
+ /* next_node is NULL if we are at the end-of-list */
+
+ return (next_node);
+ }
+
+ /* Must search for the node -- but within this scope only */
+
+ while (next_node) {
+
+ /* If type matches, we are done */
+
+ if (next_node->type == type) {
+ return (next_node);
+ }
+
+ /* Otherwise, move on to the next peer node */
+
+ next_node = next_node->peer;
+ }
+
+ /* Not found */
+
+ return (NULL);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION: acpi_ns_walk_namespace
+ *
+ * PARAMETERS: type - acpi_object_type to search for
+ * start_node - Handle in namespace where search begins
+ * max_depth - Depth to which search is to reach
+ * flags - Whether to unlock the NS before invoking
+ * the callback routine
+ * descending_callback - Called during tree descent
+ * when an object of "Type" is found
+ * ascending_callback - Called during tree ascent
+ * when an object of "Type" is found
+ * context - Passed to user function(s) above
+ * return_value - from the user_function if terminated
+ * early. Otherwise, returns NULL.
+ * RETURNS: Status
+ *
+ * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
+ * starting (and ending) at the node specified by start_handle.
+ * The callback function is called whenever a node that matches
+ * the type parameter is found. If the callback 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 callback function(s) can be
+ * tailored to each task, whether it is a print function,
+ * a compare function, etc.
+ *
+ ******************************************************************************/
+
+acpi_status
+acpi_ns_walk_namespace(acpi_object_type type,
+ acpi_handle start_node,
+ u32 max_depth,
+ u32 flags,
+ acpi_walk_callback descending_callback,
+ acpi_walk_callback ascending_callback,
+ void *context, void **return_value)
+{
+ acpi_status status;
+ acpi_status mutex_status;
+ struct acpi_namespace_node *child_node;
+ struct acpi_namespace_node *parent_node;
+ acpi_object_type child_type;
+ u32 level;
+ u8 node_previously_visited = FALSE;
+
+ ACPI_FUNCTION_TRACE(ns_walk_namespace);
+
+ /* Special case for the namespace Root Node */
+
+ if (start_node == ACPI_ROOT_OBJECT) {
+ start_node = acpi_gbl_root_node;
+ if (!start_node) {
+ return_ACPI_STATUS(AE_NO_NAMESPACE);
+ }
+ }
+
+ /* Null child means "get first node" */
+
+ parent_node = start_node;
+ child_node = acpi_ns_get_next_node(parent_node, NULL);
+ child_type = ACPI_TYPE_ANY;
+ level = 1;
+
+ /*
+ * Traverse the tree of nodes 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 && child_node) {
+ status = AE_OK;
+
+ /* Found next child, get the type if we are not searching for ANY */
+
+ if (type != ACPI_TYPE_ANY) {
+ child_type = child_node->type;
+ }
+
+ /*
+ * Ignore all temporary namespace nodes (created during control
+ * method execution) unless told otherwise. These temporary nodes
+ * can cause a race condition because they can be deleted during
+ * the execution of the user function (if the namespace is
+ * unlocked before invocation of the user function.) Only the
+ * debugger namespace dump will examine the temporary nodes.
+ */
+ if ((child_node->flags & ANOBJ_TEMPORARY) &&
+ !(flags & ACPI_NS_WALK_TEMP_NODES)) {
+ status = AE_CTRL_DEPTH;
+ }
+
+ /* Type must match requested type */
+
+ else if (child_type == type) {
+ /*
+ * Found a matching node, invoke the user callback function.
+ * Unlock the namespace if flag is set.
+ */
+ if (flags & ACPI_NS_WALK_UNLOCK) {
+ mutex_status =
+ acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
+ if (ACPI_FAILURE(mutex_status)) {
+ return_ACPI_STATUS(mutex_status);
+ }
+ }
+
+ /*
+ * Invoke the user function, either descending, ascending,
+ * or both.
+ */
+ if (!node_previously_visited) {
+ if (descending_callback) {
+ status =
+ descending_callback(child_node,
+ level, context,
+ return_value);
+ }
+ } else {
+ if (ascending_callback) {
+ status =
+ ascending_callback(child_node,
+ level, context,
+ return_value);
+ }
+ }
+
+ if (flags & ACPI_NS_WALK_UNLOCK) {
+ mutex_status =
+ acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
+ if (ACPI_FAILURE(mutex_status)) {
+ return_ACPI_STATUS(mutex_status);
+ }
+ }
+
+ switch (status) {
+ case AE_OK:
+ case AE_CTRL_DEPTH:
+
+ /* Just keep going */
+ break;
+
+ case AE_CTRL_TERMINATE:
+
+ /* Exit now, with OK status */
+
+ return_ACPI_STATUS(AE_OK);
+
+ default:
+
+ /* All others are valid exceptions */
+
+ return_ACPI_STATUS(status);
+ }
+ }
+
+ /*
+ * 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 (!node_previously_visited &&
+ (level < max_depth) && (status != AE_CTRL_DEPTH)) {
+ if (child_node->child) {
+
+ /* There is at least one child of this node, visit it */
+
+ level++;
+ parent_node = child_node;
+ child_node =
+ acpi_ns_get_next_node(parent_node, NULL);
+ continue;
+ }
+ }
+
+ /* No more children, re-visit this node */
+
+ if (!node_previously_visited) {
+ node_previously_visited = TRUE;
+ continue;
+ }
+
+ /* No more children, visit peers */
+
+ child_node = acpi_ns_get_next_node(parent_node, child_node);
+ if (child_node) {
+ node_previously_visited = FALSE;
+ }
+
+ /* No peers, re-visit parent */
+
+ else {
+ /*
+ * No more children of this node (acpi_ns_get_next_node failed), go
+ * back upwards in the namespace tree to the node's parent.
+ */
+ level--;
+ child_node = parent_node;
+ parent_node = parent_node->parent;
+
+ node_previously_visited = TRUE;
+ }
+ }
+
+ /* Complete walk, not terminated by user function */
+
+ return_ACPI_STATUS(AE_OK);
+}
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