Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /****************************************************************************** |
| 2 | * |
| 3 | * Module Name: nswalk - Functions for walking the ACPI namespace |
| 4 | * |
| 5 | *****************************************************************************/ |
| 6 | |
| 7 | /* |
Bob Moore | 4a90c7e | 2006-01-13 16:22:00 -0500 | [diff] [blame] | 8 | * Copyright (C) 2000 - 2006, R. Byron Moore |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 9 | * All rights reserved. |
| 10 | * |
| 11 | * Redistribution and use in source and binary forms, with or without |
| 12 | * modification, are permitted provided that the following conditions |
| 13 | * are met: |
| 14 | * 1. Redistributions of source code must retain the above copyright |
| 15 | * notice, this list of conditions, and the following disclaimer, |
| 16 | * without modification. |
| 17 | * 2. Redistributions in binary form must reproduce at minimum a disclaimer |
| 18 | * substantially similar to the "NO WARRANTY" disclaimer below |
| 19 | * ("Disclaimer") and any redistribution must be conditioned upon |
| 20 | * including a substantially similar Disclaimer requirement for further |
| 21 | * binary redistribution. |
| 22 | * 3. Neither the names of the above-listed copyright holders nor the names |
| 23 | * of any contributors may be used to endorse or promote products derived |
| 24 | * from this software without specific prior written permission. |
| 25 | * |
| 26 | * Alternatively, this software may be distributed under the terms of the |
| 27 | * GNU General Public License ("GPL") version 2 as published by the Free |
| 28 | * Software Foundation. |
| 29 | * |
| 30 | * NO WARRANTY |
| 31 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 32 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 33 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR |
| 34 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 35 | * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 36 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 37 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 38 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| 39 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING |
| 40 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 41 | * POSSIBILITY OF SUCH DAMAGES. |
| 42 | */ |
| 43 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | #include <acpi/acpi.h> |
| 45 | #include <acpi/acnamesp.h> |
| 46 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | #define _COMPONENT ACPI_NAMESPACE |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 48 | ACPI_MODULE_NAME("nswalk") |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | |
| 50 | /******************************************************************************* |
| 51 | * |
| 52 | * FUNCTION: acpi_ns_get_next_node |
| 53 | * |
| 54 | * PARAMETERS: Type - Type of node to be searched for |
| 55 | * parent_node - Parent node whose children we are |
Robert Moore | 44f6c01 | 2005-04-18 22:49:35 -0400 | [diff] [blame] | 56 | * getting |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | * child_node - Previous child that was found. |
| 58 | * The NEXT child will be returned |
| 59 | * |
| 60 | * RETURN: struct acpi_namespace_node - Pointer to the NEXT child or NULL if |
| 61 | * none is found. |
| 62 | * |
| 63 | * DESCRIPTION: Return the next peer node within the namespace. If Handle |
| 64 | * is valid, Scope is ignored. Otherwise, the first node |
| 65 | * within Scope is returned. |
| 66 | * |
| 67 | ******************************************************************************/ |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 68 | struct acpi_namespace_node *acpi_ns_get_next_node(acpi_object_type type, |
| 69 | struct acpi_namespace_node |
| 70 | *parent_node, |
| 71 | struct acpi_namespace_node |
| 72 | *child_node) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | { |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 74 | struct acpi_namespace_node *next_node = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 76 | ACPI_FUNCTION_ENTRY(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | |
| 78 | if (!child_node) { |
| 79 | /* It's really the parent's _scope_ that we want */ |
| 80 | |
| 81 | if (parent_node->child) { |
| 82 | next_node = parent_node->child; |
| 83 | } |
| 84 | } |
| 85 | |
| 86 | else { |
| 87 | /* Start search at the NEXT node */ |
| 88 | |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 89 | next_node = acpi_ns_get_next_valid_node(child_node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | } |
| 91 | |
| 92 | /* If any type is OK, we are done */ |
| 93 | |
| 94 | if (type == ACPI_TYPE_ANY) { |
| 95 | /* next_node is NULL if we are at the end-of-list */ |
| 96 | |
| 97 | return (next_node); |
| 98 | } |
| 99 | |
| 100 | /* Must search for the node -- but within this scope only */ |
| 101 | |
| 102 | while (next_node) { |
| 103 | /* If type matches, we are done */ |
| 104 | |
| 105 | if (next_node->type == type) { |
| 106 | return (next_node); |
| 107 | } |
| 108 | |
| 109 | /* Otherwise, move on to the next node */ |
| 110 | |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 111 | next_node = acpi_ns_get_next_valid_node(next_node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | } |
| 113 | |
| 114 | /* Not found */ |
| 115 | |
| 116 | return (NULL); |
| 117 | } |
| 118 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 119 | /******************************************************************************* |
| 120 | * |
| 121 | * FUNCTION: acpi_ns_walk_namespace |
| 122 | * |
| 123 | * PARAMETERS: Type - acpi_object_type to search for |
| 124 | * start_node - Handle in namespace where search begins |
| 125 | * max_depth - Depth to which search is to reach |
| 126 | * unlock_before_callback- Whether to unlock the NS before invoking |
| 127 | * the callback routine |
| 128 | * user_function - Called when an object of "Type" is found |
| 129 | * Context - Passed to user function |
| 130 | * return_value - from the user_function if terminated early. |
| 131 | * Otherwise, returns NULL. |
| 132 | * RETURNS: Status |
| 133 | * |
| 134 | * DESCRIPTION: Performs a modified depth-first walk of the namespace tree, |
| 135 | * starting (and ending) at the node specified by start_handle. |
| 136 | * The user_function is called whenever a node that matches |
| 137 | * the type parameter is found. If the user function returns |
| 138 | * a non-zero value, the search is terminated immediately and this |
| 139 | * value is returned to the caller. |
| 140 | * |
| 141 | * The point of this procedure is to provide a generic namespace |
| 142 | * walk routine that can be called from multiple places to |
| 143 | * provide multiple services; the User Function can be tailored |
| 144 | * to each task, whether it is a print function, a compare |
| 145 | * function, etc. |
| 146 | * |
| 147 | ******************************************************************************/ |
| 148 | |
| 149 | acpi_status |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 150 | acpi_ns_walk_namespace(acpi_object_type type, |
| 151 | acpi_handle start_node, |
| 152 | u32 max_depth, |
| 153 | u8 unlock_before_callback, |
| 154 | acpi_walk_callback user_function, |
| 155 | void *context, void **return_value) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | { |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 157 | acpi_status status; |
| 158 | acpi_status mutex_status; |
| 159 | struct acpi_namespace_node *child_node; |
| 160 | struct acpi_namespace_node *parent_node; |
| 161 | acpi_object_type child_type; |
| 162 | u32 level; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 163 | |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 164 | ACPI_FUNCTION_TRACE("ns_walk_namespace"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | |
| 166 | /* Special case for the namespace Root Node */ |
| 167 | |
| 168 | if (start_node == ACPI_ROOT_OBJECT) { |
| 169 | start_node = acpi_gbl_root_node; |
| 170 | } |
| 171 | |
| 172 | /* Null child means "get first node" */ |
| 173 | |
| 174 | parent_node = start_node; |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 175 | child_node = NULL; |
| 176 | child_type = ACPI_TYPE_ANY; |
| 177 | level = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | |
| 179 | /* |
| 180 | * Traverse the tree of nodes until we bubble back up to where we |
| 181 | * started. When Level is zero, the loop is done because we have |
| 182 | * bubbled up to (and passed) the original parent handle (start_entry) |
| 183 | */ |
| 184 | while (level > 0) { |
| 185 | /* Get the next node in this scope. Null if not found */ |
| 186 | |
| 187 | status = AE_OK; |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 188 | child_node = |
| 189 | acpi_ns_get_next_node(ACPI_TYPE_ANY, parent_node, |
| 190 | child_node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | if (child_node) { |
| 192 | /* |
| 193 | * Found node, Get the type if we are not |
| 194 | * searching for ANY |
| 195 | */ |
| 196 | if (type != ACPI_TYPE_ANY) { |
| 197 | child_type = child_node->type; |
| 198 | } |
| 199 | |
| 200 | if (child_type == type) { |
| 201 | /* |
| 202 | * Found a matching node, invoke the user |
| 203 | * callback function |
| 204 | */ |
| 205 | if (unlock_before_callback) { |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 206 | mutex_status = |
| 207 | acpi_ut_release_mutex |
| 208 | (ACPI_MTX_NAMESPACE); |
| 209 | if (ACPI_FAILURE(mutex_status)) { |
| 210 | return_ACPI_STATUS |
| 211 | (mutex_status); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 212 | } |
| 213 | } |
| 214 | |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 215 | status = user_function(child_node, level, |
| 216 | context, return_value); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 217 | |
| 218 | if (unlock_before_callback) { |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 219 | mutex_status = |
| 220 | acpi_ut_acquire_mutex |
| 221 | (ACPI_MTX_NAMESPACE); |
| 222 | if (ACPI_FAILURE(mutex_status)) { |
| 223 | return_ACPI_STATUS |
| 224 | (mutex_status); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 225 | } |
| 226 | } |
| 227 | |
| 228 | switch (status) { |
| 229 | case AE_OK: |
| 230 | case AE_CTRL_DEPTH: |
| 231 | |
| 232 | /* Just keep going */ |
| 233 | break; |
| 234 | |
| 235 | case AE_CTRL_TERMINATE: |
| 236 | |
| 237 | /* Exit now, with OK status */ |
| 238 | |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 239 | return_ACPI_STATUS(AE_OK); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | |
| 241 | default: |
| 242 | |
| 243 | /* All others are valid exceptions */ |
| 244 | |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 245 | return_ACPI_STATUS(status); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 246 | } |
| 247 | } |
| 248 | |
| 249 | /* |
| 250 | * Depth first search: |
| 251 | * Attempt to go down another level in the namespace |
| 252 | * if we are allowed to. Don't go any further if we |
| 253 | * have reached the caller specified maximum depth |
| 254 | * or if the user function has specified that the |
| 255 | * maximum depth has been reached. |
| 256 | */ |
| 257 | if ((level < max_depth) && (status != AE_CTRL_DEPTH)) { |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 258 | if (acpi_ns_get_next_node |
| 259 | (ACPI_TYPE_ANY, child_node, NULL)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 260 | /* |
| 261 | * There is at least one child of this |
| 262 | * node, visit the onde |
| 263 | */ |
| 264 | level++; |
| 265 | parent_node = child_node; |
| 266 | child_node = NULL; |
| 267 | } |
| 268 | } |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 269 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 270 | /* |
| 271 | * No more children of this node (acpi_ns_get_next_node |
| 272 | * failed), go back upwards in the namespace tree to |
| 273 | * the node's parent. |
| 274 | */ |
| 275 | level--; |
| 276 | child_node = parent_node; |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 277 | parent_node = acpi_ns_get_parent_node(parent_node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 278 | } |
| 279 | } |
| 280 | |
| 281 | /* Complete walk, not terminated by user function */ |
| 282 | |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 283 | return_ACPI_STATUS(AE_OK); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 284 | } |