1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /*******************************************************************************
3  *
4  * Module Name: nsalloc - Namespace allocation and deletion utilities
5  *
6  ******************************************************************************/
7 
8 #include <acpi/acpi.h>
9 #include "accommon.h"
10 #include "acnamesp.h"
11 
12 #define _COMPONENT          ACPI_NAMESPACE
13 ACPI_MODULE_NAME("nsalloc")
14 
15 /*******************************************************************************
16  *
17  * FUNCTION:    acpi_ns_create_node
18  *
19  * PARAMETERS:  name            - Name of the new node (4 char ACPI name)
20  *
21  * RETURN:      New namespace node (Null on failure)
22  *
23  * DESCRIPTION: Create a namespace node
24  *
25  ******************************************************************************/
acpi_ns_create_node(u32 name)26 struct acpi_namespace_node *acpi_ns_create_node(u32 name)
27 {
28 	struct acpi_namespace_node *node;
29 #ifdef ACPI_DBG_TRACK_ALLOCATIONS
30 	u32 temp;
31 #endif
32 
33 	ACPI_FUNCTION_TRACE(ns_create_node);
34 
35 	node = acpi_os_acquire_object(acpi_gbl_namespace_cache);
36 	if (!node) {
37 		return_PTR(NULL);
38 	}
39 
40 	ACPI_MEM_TRACKING(acpi_gbl_ns_node_list->total_allocated++);
41 
42 #ifdef ACPI_DBG_TRACK_ALLOCATIONS
43 	temp = acpi_gbl_ns_node_list->total_allocated -
44 	    acpi_gbl_ns_node_list->total_freed;
45 	if (temp > acpi_gbl_ns_node_list->max_occupied) {
46 		acpi_gbl_ns_node_list->max_occupied = temp;
47 	}
48 #endif
49 
50 	node->name.integer = name;
51 	ACPI_SET_DESCRIPTOR_TYPE(node, ACPI_DESC_TYPE_NAMED);
52 	return_PTR(node);
53 }
54 
55 /*******************************************************************************
56  *
57  * FUNCTION:    acpi_ns_delete_node
58  *
59  * PARAMETERS:  node            - Node to be deleted
60  *
61  * RETURN:      None
62  *
63  * DESCRIPTION: Delete a namespace node. All node deletions must come through
64  *              here. Detaches any attached objects, including any attached
65  *              data. If a handler is associated with attached data, it is
66  *              invoked before the node is deleted.
67  *
68  ******************************************************************************/
69 
acpi_ns_delete_node(struct acpi_namespace_node * node)70 void acpi_ns_delete_node(struct acpi_namespace_node *node)
71 {
72 	union acpi_operand_object *obj_desc;
73 	union acpi_operand_object *next_desc;
74 
75 	ACPI_FUNCTION_NAME(ns_delete_node);
76 
77 	if (!node) {
78 		return_VOID;
79 	}
80 
81 	/* Detach an object if there is one */
82 
83 	acpi_ns_detach_object(node);
84 
85 	/*
86 	 * Delete an attached data object list if present (objects that were
87 	 * attached via acpi_attach_data). Note: After any normal object is
88 	 * detached above, the only possible remaining object(s) are data
89 	 * objects, in a linked list.
90 	 */
91 	obj_desc = node->object;
92 	while (obj_desc && (obj_desc->common.type == ACPI_TYPE_LOCAL_DATA)) {
93 
94 		/* Invoke the attached data deletion handler if present */
95 
96 		if (obj_desc->data.handler) {
97 			obj_desc->data.handler(node, obj_desc->data.pointer);
98 		}
99 
100 		next_desc = obj_desc->common.next_object;
101 		acpi_ut_remove_reference(obj_desc);
102 		obj_desc = next_desc;
103 	}
104 
105 	/* Special case for the statically allocated root node */
106 
107 	if (node == acpi_gbl_root_node) {
108 		return;
109 	}
110 
111 	/* Now we can delete the node */
112 
113 	(void)acpi_os_release_object(acpi_gbl_namespace_cache, node);
114 
115 	ACPI_MEM_TRACKING(acpi_gbl_ns_node_list->total_freed++);
116 	ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS, "Node %p, Remaining %X\n",
117 			  node, acpi_gbl_current_node_count));
118 }
119 
120 /*******************************************************************************
121  *
122  * FUNCTION:    acpi_ns_remove_node
123  *
124  * PARAMETERS:  node            - Node to be removed/deleted
125  *
126  * RETURN:      None
127  *
128  * DESCRIPTION: Remove (unlink) and delete a namespace node
129  *
130  ******************************************************************************/
131 
acpi_ns_remove_node(struct acpi_namespace_node * node)132 void acpi_ns_remove_node(struct acpi_namespace_node *node)
133 {
134 	struct acpi_namespace_node *parent_node;
135 	struct acpi_namespace_node *prev_node;
136 	struct acpi_namespace_node *next_node;
137 
138 	ACPI_FUNCTION_TRACE_PTR(ns_remove_node, node);
139 
140 	parent_node = node->parent;
141 
142 	prev_node = NULL;
143 	next_node = parent_node->child;
144 
145 	/* Find the node that is the previous peer in the parent's child list */
146 
147 	while (next_node != node) {
148 		prev_node = next_node;
149 		next_node = next_node->peer;
150 	}
151 
152 	if (prev_node) {
153 
154 		/* Node is not first child, unlink it */
155 
156 		prev_node->peer = node->peer;
157 	} else {
158 		/*
159 		 * Node is first child (has no previous peer).
160 		 * Link peer list to parent
161 		 */
162 		parent_node->child = node->peer;
163 	}
164 
165 	/* Delete the node and any attached objects */
166 
167 	acpi_ns_delete_node(node);
168 	return_VOID;
169 }
170 
171 /*******************************************************************************
172  *
173  * FUNCTION:    acpi_ns_install_node
174  *
175  * PARAMETERS:  walk_state      - Current state of the walk
176  *              parent_node     - The parent of the new Node
177  *              node            - The new Node to install
178  *              type            - ACPI object type of the new Node
179  *
180  * RETURN:      None
181  *
182  * DESCRIPTION: Initialize a new namespace node and install it amongst
183  *              its peers.
184  *
185  *              Note: Current namespace lookup is linear search. This appears
186  *              to be sufficient as namespace searches consume only a small
187  *              fraction of the execution time of the ACPI subsystem.
188  *
189  ******************************************************************************/
190 
acpi_ns_install_node(struct acpi_walk_state * walk_state,struct acpi_namespace_node * parent_node,struct acpi_namespace_node * node,acpi_object_type type)191 void acpi_ns_install_node(struct acpi_walk_state *walk_state, struct acpi_namespace_node *parent_node,	/* Parent */
192 			  struct acpi_namespace_node *node,	/* New Child */
193 			  acpi_object_type type)
194 {
195 	acpi_owner_id owner_id = 0;
196 	struct acpi_namespace_node *child_node;
197 
198 	ACPI_FUNCTION_TRACE(ns_install_node);
199 
200 	if (walk_state) {
201 		/*
202 		 * Get the owner ID from the Walk state. The owner ID is used to
203 		 * track table deletion and deletion of objects created by methods.
204 		 */
205 		owner_id = walk_state->owner_id;
206 
207 		if ((walk_state->method_desc) &&
208 		    (parent_node != walk_state->method_node)) {
209 			/*
210 			 * A method is creating a new node that is not a child of the
211 			 * method (it is non-local). Mark the executing method as having
212 			 * modified the namespace. This is used for cleanup when the
213 			 * method exits.
214 			 */
215 			walk_state->method_desc->method.info_flags |=
216 			    ACPI_METHOD_MODIFIED_NAMESPACE;
217 		}
218 	}
219 
220 	/* Link the new entry into the parent and existing children */
221 
222 	node->peer = NULL;
223 	node->parent = parent_node;
224 	child_node = parent_node->child;
225 
226 	if (!child_node) {
227 		parent_node->child = node;
228 	} else {
229 		/* Add node to the end of the peer list */
230 
231 		while (child_node->peer) {
232 			child_node = child_node->peer;
233 		}
234 
235 		child_node->peer = node;
236 	}
237 
238 	/* Init the new entry */
239 
240 	node->owner_id = owner_id;
241 	node->type = (u8) type;
242 
243 	ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
244 			  "%4.4s (%s) [Node %p Owner %3.3X] added to %4.4s (%s) [Node %p]\n",
245 			  acpi_ut_get_node_name(node),
246 			  acpi_ut_get_type_name(node->type), node, owner_id,
247 			  acpi_ut_get_node_name(parent_node),
248 			  acpi_ut_get_type_name(parent_node->type),
249 			  parent_node));
250 
251 	return_VOID;
252 }
253 
254 /*******************************************************************************
255  *
256  * FUNCTION:    acpi_ns_delete_children
257  *
258  * PARAMETERS:  parent_node     - Delete this objects children
259  *
260  * RETURN:      None.
261  *
262  * DESCRIPTION: Delete all children of the parent object. In other words,
263  *              deletes a "scope".
264  *
265  ******************************************************************************/
266 
acpi_ns_delete_children(struct acpi_namespace_node * parent_node)267 void acpi_ns_delete_children(struct acpi_namespace_node *parent_node)
268 {
269 	struct acpi_namespace_node *next_node;
270 	struct acpi_namespace_node *node_to_delete;
271 
272 	ACPI_FUNCTION_TRACE_PTR(ns_delete_children, parent_node);
273 
274 	if (!parent_node) {
275 		return_VOID;
276 	}
277 
278 	/* Deallocate all children at this level */
279 
280 	next_node = parent_node->child;
281 	while (next_node) {
282 
283 		/* Grandchildren should have all been deleted already */
284 
285 		if (next_node->child) {
286 			ACPI_ERROR((AE_INFO, "Found a grandchild! P=%p C=%p",
287 				    parent_node, next_node));
288 		}
289 
290 		/*
291 		 * Delete this child node and move on to the next child in the list.
292 		 * No need to unlink the node since we are deleting the entire branch.
293 		 */
294 		node_to_delete = next_node;
295 		next_node = next_node->peer;
296 		acpi_ns_delete_node(node_to_delete);
297 	}
298 
299 	/* Clear the parent's child pointer */
300 
301 	parent_node->child = NULL;
302 	return_VOID;
303 }
304 
305 /*******************************************************************************
306  *
307  * FUNCTION:    acpi_ns_delete_namespace_subtree
308  *
309  * PARAMETERS:  parent_node     - Root of the subtree to be deleted
310  *
311  * RETURN:      None.
312  *
313  * DESCRIPTION: Delete a subtree of the namespace. This includes all objects
314  *              stored within the subtree.
315  *
316  ******************************************************************************/
317 
acpi_ns_delete_namespace_subtree(struct acpi_namespace_node * parent_node)318 void acpi_ns_delete_namespace_subtree(struct acpi_namespace_node *parent_node)
319 {
320 	struct acpi_namespace_node *child_node = NULL;
321 	u32 level = 1;
322 	acpi_status status;
323 
324 	ACPI_FUNCTION_TRACE(ns_delete_namespace_subtree);
325 
326 	if (!parent_node) {
327 		return_VOID;
328 	}
329 
330 	/* Lock namespace for possible update */
331 
332 	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
333 	if (ACPI_FAILURE(status)) {
334 		return_VOID;
335 	}
336 
337 	/*
338 	 * Traverse the tree of objects until we bubble back up
339 	 * to where we started.
340 	 */
341 	while (level > 0) {
342 
343 		/* Get the next node in this scope (NULL if none) */
344 
345 		child_node = acpi_ns_get_next_node(parent_node, child_node);
346 		if (child_node) {
347 
348 			/* Found a child node - detach any attached object */
349 
350 			acpi_ns_detach_object(child_node);
351 
352 			/* Check if this node has any children */
353 
354 			if (child_node->child) {
355 				/*
356 				 * There is at least one child of this node,
357 				 * visit the node
358 				 */
359 				level++;
360 				parent_node = child_node;
361 				child_node = NULL;
362 			}
363 		} else {
364 			/*
365 			 * No more children of this parent node.
366 			 * Move up to the grandparent.
367 			 */
368 			level--;
369 
370 			/*
371 			 * Now delete all of the children of this parent
372 			 * all at the same time.
373 			 */
374 			acpi_ns_delete_children(parent_node);
375 
376 			/* New "last child" is this parent node */
377 
378 			child_node = parent_node;
379 
380 			/* Move up the tree to the grandparent */
381 
382 			parent_node = parent_node->parent;
383 		}
384 	}
385 
386 	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
387 	return_VOID;
388 }
389 
390 /*******************************************************************************
391  *
392  * FUNCTION:    acpi_ns_delete_namespace_by_owner
393  *
394  * PARAMETERS:  owner_id    - All nodes with this owner will be deleted
395  *
396  * RETURN:      Status
397  *
398  * DESCRIPTION: Delete entries within the namespace that are owned by a
399  *              specific ID. Used to delete entire ACPI tables. All
400  *              reference counts are updated.
401  *
402  * MUTEX:       Locks namespace during deletion walk.
403  *
404  ******************************************************************************/
405 
acpi_ns_delete_namespace_by_owner(acpi_owner_id owner_id)406 void acpi_ns_delete_namespace_by_owner(acpi_owner_id owner_id)
407 {
408 	struct acpi_namespace_node *child_node;
409 	struct acpi_namespace_node *deletion_node;
410 	struct acpi_namespace_node *parent_node;
411 	u32 level;
412 	acpi_status status;
413 
414 	ACPI_FUNCTION_TRACE_U32(ns_delete_namespace_by_owner, owner_id);
415 
416 	if (owner_id == 0) {
417 		return_VOID;
418 	}
419 
420 	/* Lock namespace for possible update */
421 
422 	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
423 	if (ACPI_FAILURE(status)) {
424 		return_VOID;
425 	}
426 
427 	deletion_node = NULL;
428 	parent_node = acpi_gbl_root_node;
429 	child_node = NULL;
430 	level = 1;
431 
432 	/*
433 	 * Traverse the tree of nodes until we bubble back up
434 	 * to where we started.
435 	 */
436 	while (level > 0) {
437 		/*
438 		 * Get the next child of this parent node. When child_node is NULL,
439 		 * the first child of the parent is returned
440 		 */
441 		child_node = acpi_ns_get_next_node(parent_node, child_node);
442 
443 		if (deletion_node) {
444 			acpi_ns_delete_children(deletion_node);
445 			acpi_ns_remove_node(deletion_node);
446 			deletion_node = NULL;
447 		}
448 
449 		if (child_node) {
450 			if (child_node->owner_id == owner_id) {
451 
452 				/* Found a matching child node - detach any attached object */
453 
454 				acpi_ns_detach_object(child_node);
455 			}
456 
457 			/* Check if this node has any children */
458 
459 			if (child_node->child) {
460 				/*
461 				 * There is at least one child of this node,
462 				 * visit the node
463 				 */
464 				level++;
465 				parent_node = child_node;
466 				child_node = NULL;
467 			} else if (child_node->owner_id == owner_id) {
468 				deletion_node = child_node;
469 			}
470 		} else {
471 			/*
472 			 * No more children of this parent node.
473 			 * Move up to the grandparent.
474 			 */
475 			level--;
476 			if (level != 0) {
477 				if (parent_node->owner_id == owner_id) {
478 					deletion_node = parent_node;
479 				}
480 			}
481 
482 			/* New "last child" is this parent node */
483 
484 			child_node = parent_node;
485 
486 			/* Move up the tree to the grandparent */
487 
488 			parent_node = parent_node->parent;
489 		}
490 	}
491 
492 	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
493 	return_VOID;
494 }
495