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| 6595 | serge | 1 | /****************************************************************************** |
| 2 | * |
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| 3 | * Module Name: nswalk - Functions for walking the ACPI namespace |
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| 4 | * |
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| 5 | *****************************************************************************/ |
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| 6 | |||
| 7 | /* |
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| 8 | * Copyright (C) 2000 - 2015, Intel Corp. |
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| 9 | * All rights reserved. |
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| 10 | * |
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| 11 | * Redistribution and use in source and binary forms, with or without |
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| 12 | * modification, are permitted provided that the following conditions |
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| 13 | * are met: |
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| 14 | * 1. Redistributions of source code must retain the above copyright |
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| 15 | * notice, this list of conditions, and the following disclaimer, |
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| 16 | * without modification. |
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| 17 | * 2. Redistributions in binary form must reproduce at minimum a disclaimer |
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| 18 | * substantially similar to the "NO WARRANTY" disclaimer below |
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| 19 | * ("Disclaimer") and any redistribution must be conditioned upon |
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| 20 | * including a substantially similar Disclaimer requirement for further |
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| 21 | * binary redistribution. |
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| 22 | * 3. Neither the names of the above-listed copyright holders nor the names |
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| 23 | * of any contributors may be used to endorse or promote products derived |
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| 24 | * from this software without specific prior written permission. |
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| 25 | * |
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| 26 | * Alternatively, this software may be distributed under the terms of the |
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| 27 | * GNU General Public License ("GPL") version 2 as published by the Free |
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| 28 | * Software Foundation. |
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| 29 | * |
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| 30 | * NO WARRANTY |
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| 31 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
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| 32 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
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| 33 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR |
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| 34 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
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| 35 | * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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| 36 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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| 37 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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| 38 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
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| 39 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING |
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| 40 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
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| 41 | * POSSIBILITY OF SUCH DAMAGES. |
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| 42 | */ |
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| 43 | |||
| 44 | #include |
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| 45 | #include "accommon.h" |
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| 46 | #include "acnamesp.h" |
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| 47 | |||
| 48 | #define _COMPONENT ACPI_NAMESPACE |
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| 49 | ACPI_MODULE_NAME("nswalk") |
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| 50 | |||
| 51 | /******************************************************************************* |
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| 52 | * |
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| 53 | * FUNCTION: acpi_ns_get_next_node |
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| 54 | * |
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| 55 | * PARAMETERS: parent_node - Parent node whose children we are |
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| 56 | * getting |
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| 57 | * child_node - Previous child that was found. |
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| 58 | * The NEXT child will be returned |
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| 59 | * |
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| 60 | * RETURN: struct acpi_namespace_node - Pointer to the NEXT child or NULL if |
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| 61 | * none is found. |
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| 62 | * |
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| 63 | * DESCRIPTION: Return the next peer node within the namespace. If Handle |
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| 64 | * is valid, Scope is ignored. Otherwise, the first node |
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| 65 | * within Scope is returned. |
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| 66 | * |
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| 67 | ******************************************************************************/ |
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| 68 | struct acpi_namespace_node *acpi_ns_get_next_node(struct acpi_namespace_node |
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| 69 | *parent_node, |
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| 70 | struct acpi_namespace_node |
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| 71 | *child_node) |
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| 72 | { |
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| 73 | ACPI_FUNCTION_ENTRY(); |
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| 74 | |||
| 75 | if (!child_node) { |
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| 76 | |||
| 77 | /* It's really the parent's _scope_ that we want */ |
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| 78 | |||
| 79 | return (parent_node->child); |
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| 80 | } |
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| 81 | |||
| 82 | /* Otherwise just return the next peer */ |
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| 83 | |||
| 84 | return (child_node->peer); |
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| 85 | } |
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| 86 | |||
| 87 | /******************************************************************************* |
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| 88 | * |
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| 89 | * FUNCTION: acpi_ns_get_next_node_typed |
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| 90 | * |
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| 91 | * PARAMETERS: type - Type of node to be searched for |
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| 92 | * parent_node - Parent node whose children we are |
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| 93 | * getting |
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| 94 | * child_node - Previous child that was found. |
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| 95 | * The NEXT child will be returned |
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| 96 | * |
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| 97 | * RETURN: struct acpi_namespace_node - Pointer to the NEXT child or NULL if |
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| 98 | * none is found. |
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| 99 | * |
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| 100 | * DESCRIPTION: Return the next peer node within the namespace. If Handle |
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| 101 | * is valid, Scope is ignored. Otherwise, the first node |
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| 102 | * within Scope is returned. |
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| 103 | * |
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| 104 | ******************************************************************************/ |
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| 105 | |||
| 106 | struct acpi_namespace_node *acpi_ns_get_next_node_typed(acpi_object_type type, |
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| 107 | struct |
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| 108 | acpi_namespace_node |
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| 109 | *parent_node, |
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| 110 | struct |
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| 111 | acpi_namespace_node |
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| 112 | *child_node) |
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| 113 | { |
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| 114 | struct acpi_namespace_node *next_node = NULL; |
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| 115 | |||
| 116 | ACPI_FUNCTION_ENTRY(); |
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| 117 | |||
| 118 | next_node = acpi_ns_get_next_node(parent_node, child_node); |
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| 119 | |||
| 120 | |||
| 121 | /* If any type is OK, we are done */ |
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| 122 | |||
| 123 | if (type == ACPI_TYPE_ANY) { |
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| 124 | |||
| 125 | /* next_node is NULL if we are at the end-of-list */ |
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| 126 | |||
| 127 | return (next_node); |
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| 128 | } |
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| 129 | |||
| 130 | /* Must search for the node -- but within this scope only */ |
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| 131 | |||
| 132 | while (next_node) { |
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| 133 | |||
| 134 | /* If type matches, we are done */ |
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| 135 | |||
| 136 | if (next_node->type == type) { |
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| 137 | return (next_node); |
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| 138 | } |
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| 139 | |||
| 140 | /* Otherwise, move on to the next peer node */ |
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| 141 | |||
| 142 | next_node = next_node->peer; |
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| 143 | } |
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| 144 | |||
| 145 | /* Not found */ |
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| 146 | |||
| 147 | return (NULL); |
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| 148 | } |
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| 149 | |||
| 150 | /******************************************************************************* |
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| 151 | * |
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| 152 | * FUNCTION: acpi_ns_walk_namespace |
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| 153 | * |
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| 154 | * PARAMETERS: type - acpi_object_type to search for |
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| 155 | * start_node - Handle in namespace where search begins |
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| 156 | * max_depth - Depth to which search is to reach |
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| 157 | * flags - Whether to unlock the NS before invoking |
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| 158 | * the callback routine |
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| 159 | * descending_callback - Called during tree descent |
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| 160 | * when an object of "Type" is found |
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| 161 | * ascending_callback - Called during tree ascent |
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| 162 | * when an object of "Type" is found |
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| 163 | * context - Passed to user function(s) above |
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| 164 | * return_value - from the user_function if terminated |
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| 165 | * early. Otherwise, returns NULL. |
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| 166 | * RETURNS: Status |
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| 167 | * |
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| 168 | * DESCRIPTION: Performs a modified depth-first walk of the namespace tree, |
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| 169 | * starting (and ending) at the node specified by start_handle. |
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| 170 | * The callback function is called whenever a node that matches |
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| 171 | * the type parameter is found. If the callback function returns |
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| 172 | * a non-zero value, the search is terminated immediately and |
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| 173 | * this value is returned to the caller. |
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| 174 | * |
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| 175 | * The point of this procedure is to provide a generic namespace |
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| 176 | * walk routine that can be called from multiple places to |
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| 177 | * provide multiple services; the callback function(s) can be |
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| 178 | * tailored to each task, whether it is a print function, |
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| 179 | * a compare function, etc. |
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| 180 | * |
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| 181 | ******************************************************************************/ |
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| 182 | |||
| 183 | acpi_status |
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| 184 | acpi_ns_walk_namespace(acpi_object_type type, |
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| 185 | acpi_handle start_node, |
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| 186 | u32 max_depth, |
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| 187 | u32 flags, |
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| 188 | acpi_walk_callback descending_callback, |
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| 189 | acpi_walk_callback ascending_callback, |
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| 190 | void *context, void **return_value) |
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| 191 | { |
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| 192 | acpi_status status; |
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| 193 | acpi_status mutex_status; |
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| 194 | struct acpi_namespace_node *child_node; |
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| 195 | struct acpi_namespace_node *parent_node; |
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| 196 | acpi_object_type child_type; |
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| 197 | u32 level; |
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| 198 | u8 node_previously_visited = FALSE; |
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| 199 | |||
| 200 | ACPI_FUNCTION_TRACE(ns_walk_namespace); |
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| 201 | |||
| 202 | /* Special case for the namespace Root Node */ |
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| 203 | |||
| 204 | if (start_node == ACPI_ROOT_OBJECT) { |
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| 205 | start_node = acpi_gbl_root_node; |
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| 206 | } |
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| 207 | |||
| 208 | /* Null child means "get first node" */ |
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| 209 | |||
| 210 | parent_node = start_node; |
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| 211 | child_node = acpi_ns_get_next_node(parent_node, NULL); |
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| 212 | child_type = ACPI_TYPE_ANY; |
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| 213 | level = 1; |
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| 214 | |||
| 215 | /* |
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| 216 | * Traverse the tree of nodes until we bubble back up to where we |
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| 217 | * started. When Level is zero, the loop is done because we have |
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| 218 | * bubbled up to (and passed) the original parent handle (start_entry) |
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| 219 | */ |
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| 220 | while (level > 0 && child_node) { |
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| 221 | status = AE_OK; |
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| 222 | |||
| 223 | /* Found next child, get the type if we are not searching for ANY */ |
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| 224 | |||
| 225 | if (type != ACPI_TYPE_ANY) { |
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| 226 | child_type = child_node->type; |
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| 227 | } |
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| 228 | |||
| 229 | /* |
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| 230 | * Ignore all temporary namespace nodes (created during control |
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| 231 | * method execution) unless told otherwise. These temporary nodes |
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| 232 | * can cause a race condition because they can be deleted during |
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| 233 | * the execution of the user function (if the namespace is |
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| 234 | * unlocked before invocation of the user function.) Only the |
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| 235 | * debugger namespace dump will examine the temporary nodes. |
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| 236 | */ |
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| 237 | if ((child_node->flags & ANOBJ_TEMPORARY) && |
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| 238 | !(flags & ACPI_NS_WALK_TEMP_NODES)) { |
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| 239 | status = AE_CTRL_DEPTH; |
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| 240 | } |
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| 241 | |||
| 242 | /* Type must match requested type */ |
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| 243 | |||
| 244 | else if (child_type == type) { |
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| 245 | /* |
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| 246 | * Found a matching node, invoke the user callback function. |
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| 247 | * Unlock the namespace if flag is set. |
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| 248 | */ |
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| 249 | if (flags & ACPI_NS_WALK_UNLOCK) { |
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| 250 | mutex_status = |
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| 251 | acpi_ut_release_mutex(ACPI_MTX_NAMESPACE); |
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| 252 | if (ACPI_FAILURE(mutex_status)) { |
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| 253 | return_ACPI_STATUS(mutex_status); |
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| 254 | } |
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| 255 | } |
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| 256 | |||
| 257 | /* |
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| 258 | * Invoke the user function, either descending, ascending, |
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| 259 | * or both. |
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| 260 | */ |
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| 261 | if (!node_previously_visited) { |
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| 262 | if (descending_callback) { |
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| 263 | status = |
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| 264 | descending_callback(child_node, |
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| 265 | level, context, |
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| 266 | return_value); |
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| 267 | } |
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| 268 | } else { |
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| 269 | if (ascending_callback) { |
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| 270 | status = |
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| 271 | ascending_callback(child_node, |
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| 272 | level, context, |
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| 273 | return_value); |
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| 274 | } |
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| 275 | } |
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| 276 | |||
| 277 | if (flags & ACPI_NS_WALK_UNLOCK) { |
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| 278 | mutex_status = |
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| 279 | acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE); |
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| 280 | if (ACPI_FAILURE(mutex_status)) { |
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| 281 | return_ACPI_STATUS(mutex_status); |
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| 282 | } |
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| 283 | } |
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| 284 | |||
| 285 | switch (status) { |
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| 286 | case AE_OK: |
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| 287 | case AE_CTRL_DEPTH: |
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| 288 | |||
| 289 | /* Just keep going */ |
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| 290 | break; |
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| 291 | |||
| 292 | case AE_CTRL_TERMINATE: |
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| 293 | |||
| 294 | /* Exit now, with OK status */ |
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| 295 | |||
| 296 | return_ACPI_STATUS(AE_OK); |
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| 297 | |||
| 298 | default: |
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| 299 | |||
| 300 | /* All others are valid exceptions */ |
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| 301 | |||
| 302 | return_ACPI_STATUS(status); |
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| 303 | } |
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| 304 | } |
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| 305 | |||
| 306 | /* |
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| 307 | * Depth first search: Attempt to go down another level in the |
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| 308 | * namespace if we are allowed to. Don't go any further if we have |
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| 309 | * reached the caller specified maximum depth or if the user |
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| 310 | * function has specified that the maximum depth has been reached. |
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| 311 | */ |
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| 312 | if (!node_previously_visited && |
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| 313 | (level < max_depth) && (status != AE_CTRL_DEPTH)) { |
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| 314 | if (child_node->child) { |
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| 315 | |||
| 316 | /* There is at least one child of this node, visit it */ |
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| 317 | |||
| 318 | level++; |
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| 319 | parent_node = child_node; |
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| 320 | child_node = |
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| 321 | acpi_ns_get_next_node(parent_node, NULL); |
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| 322 | continue; |
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| 323 | } |
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| 324 | } |
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| 325 | |||
| 326 | /* No more children, re-visit this node */ |
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| 327 | |||
| 328 | if (!node_previously_visited) { |
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| 329 | node_previously_visited = TRUE; |
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| 330 | continue; |
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| 331 | } |
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| 332 | |||
| 333 | /* No more children, visit peers */ |
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| 334 | |||
| 335 | child_node = acpi_ns_get_next_node(parent_node, child_node); |
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| 336 | if (child_node) { |
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| 337 | node_previously_visited = FALSE; |
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| 338 | } |
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| 339 | |||
| 340 | /* No peers, re-visit parent */ |
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| 341 | |||
| 342 | else { |
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| 343 | /* |
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| 344 | * No more children of this node (acpi_ns_get_next_node failed), go |
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| 345 | * back upwards in the namespace tree to the node's parent. |
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| 346 | */ |
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| 347 | level--; |
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| 348 | child_node = parent_node; |
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| 349 | parent_node = parent_node->parent; |
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| 350 | |||
| 351 | node_previously_visited = TRUE; |
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| 352 | } |
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| 353 | } |
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| 354 | |||
| 355 | /* Complete walk, not terminated by user function */ |
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| 356 | |||
| 357 | return_ACPI_STATUS(AE_OK); |
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| 358 | } |