summaryrefslogtreecommitdiff
path: root/drivers/acpi/namespace/nsaccess.c
blob: 1c0c12336c57335cdc5fa6bf489570a2c96c5183 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
/*******************************************************************************
 *
 * Module Name: nsaccess - Top-level functions for accessing ACPI namespace
 *
 ******************************************************************************/

/*
 * Copyright (C) 2000 - 2005, R. Byron Moore
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 */


#include <acpi/acpi.h>
#include <acpi/amlcode.h>
#include <acpi/acnamesp.h>
#include <acpi/acdispat.h>


#define _COMPONENT          ACPI_NAMESPACE
	 ACPI_MODULE_NAME    ("nsaccess")


/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_root_initialize
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Allocate and initialize the default root named objects
 *
 * MUTEX:       Locks namespace for entire execution
 *
 ******************************************************************************/

acpi_status
acpi_ns_root_initialize (void)
{
	acpi_status                         status;
	const struct acpi_predefined_names *init_val = NULL;
	struct acpi_namespace_node          *new_node;
	union acpi_operand_object           *obj_desc;
	acpi_string                         val = NULL;


	ACPI_FUNCTION_TRACE ("ns_root_initialize");


	status = acpi_ut_acquire_mutex (ACPI_MTX_NAMESPACE);
	if (ACPI_FAILURE (status)) {
		return_ACPI_STATUS (status);
	}

	/*
	 * The global root ptr is initially NULL, so a non-NULL value indicates
	 * that acpi_ns_root_initialize() has already been called; just return.
	 */
	if (acpi_gbl_root_node) {
		status = AE_OK;
		goto unlock_and_exit;
	}

	/*
	 * Tell the rest of the subsystem that the root is initialized
	 * (This is OK because the namespace is locked)
	 */
	acpi_gbl_root_node = &acpi_gbl_root_node_struct;

	/* Enter the pre-defined names in the name table */

	ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
		"Entering predefined entries into namespace\n"));

	for (init_val = acpi_gbl_pre_defined_names; init_val->name; init_val++) {
		/* _OSI is optional for now, will be permanent later */

		if (!ACPI_STRCMP (init_val->name, "_OSI") && !acpi_gbl_create_osi_method) {
			continue;
		}

		status = acpi_ns_lookup (NULL, init_val->name, init_val->type,
				  ACPI_IMODE_LOAD_PASS2, ACPI_NS_NO_UPSEARCH,
				  NULL, &new_node);

		if (ACPI_FAILURE (status) || (!new_node)) /* Must be on same line for code converter */ {
			ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
				"Could not create predefined name %s, %s\n",
				init_val->name, acpi_format_exception (status)));
		}

		/*
		 * Name entered successfully.
		 * If entry in pre_defined_names[] specifies an
		 * initial value, create the initial value.
		 */
		if (init_val->val) {
			status = acpi_os_predefined_override (init_val, &val);
			if (ACPI_FAILURE (status)) {
				ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
					"Could not override predefined %s\n",
					init_val->name));
			}

			if (!val) {
				val = init_val->val;
			}

			/*
			 * Entry requests an initial value, allocate a
			 * descriptor for it.
			 */
			obj_desc = acpi_ut_create_internal_object (init_val->type);
			if (!obj_desc) {
				status = AE_NO_MEMORY;
				goto unlock_and_exit;
			}

			/*
			 * Convert value string from table entry to
			 * internal representation. Only types actually
			 * used for initial values are implemented here.
			 */
			switch (init_val->type) {
			case ACPI_TYPE_METHOD:
				obj_desc->method.param_count = (u8) ACPI_TO_INTEGER (val);
				obj_desc->common.flags |= AOPOBJ_DATA_VALID;

#if defined (_ACPI_ASL_COMPILER) || defined (_ACPI_DUMP_App)

				/*
				 * i_aSL Compiler cheats by putting parameter count
				 * in the owner_iD
				 */
				new_node->owner_id = obj_desc->method.param_count;
#else
				/* Mark this as a very SPECIAL method */

				obj_desc->method.method_flags = AML_METHOD_INTERNAL_ONLY;
				obj_desc->method.implementation = acpi_ut_osi_implementation;
#endif
				break;

			case ACPI_TYPE_INTEGER:

				obj_desc->integer.value = ACPI_TO_INTEGER (val);
				break;


			case ACPI_TYPE_STRING:

				/*
				 * Build an object around the static string
				 */
				obj_desc->string.length = (u32) ACPI_STRLEN (val);
				obj_desc->string.pointer = val;
				obj_desc->common.flags |= AOPOBJ_STATIC_POINTER;
				break;


			case ACPI_TYPE_MUTEX:

				obj_desc->mutex.node = new_node;
				obj_desc->mutex.sync_level = (u8) (ACPI_TO_INTEGER (val) - 1);

				if (ACPI_STRCMP (init_val->name, "_GL_") == 0) {
					/*
					 * Create a counting semaphore for the
					 * global lock
					 */
					status = acpi_os_create_semaphore (ACPI_NO_UNIT_LIMIT,
							 1, &obj_desc->mutex.semaphore);
					if (ACPI_FAILURE (status)) {
						acpi_ut_remove_reference (obj_desc);
						goto unlock_and_exit;
					}

					/*
					 * We just created the mutex for the
					 * global lock, save it
					 */
					acpi_gbl_global_lock_semaphore = obj_desc->mutex.semaphore;
				}
				else {
					/* Create a mutex */

					status = acpi_os_create_semaphore (1, 1,
							   &obj_desc->mutex.semaphore);
					if (ACPI_FAILURE (status)) {
						acpi_ut_remove_reference (obj_desc);
						goto unlock_and_exit;
					}
				}
				break;


			default:

				ACPI_REPORT_ERROR (("Unsupported initial type value %X\n",
					init_val->type));
				acpi_ut_remove_reference (obj_desc);
				obj_desc = NULL;
				continue;
			}

			/* Store pointer to value descriptor in the Node */

			status = acpi_ns_attach_object (new_node, obj_desc,
					 ACPI_GET_OBJECT_TYPE (obj_desc));

			/* Remove local reference to the object */

			acpi_ut_remove_reference (obj_desc);
		}
	}


unlock_and_exit:
	(void) acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);

	/* Save a handle to "_GPE", it is always present */

	if (ACPI_SUCCESS (status)) {
		status = acpi_ns_get_node_by_path ("\\_GPE", NULL, ACPI_NS_NO_UPSEARCH,
				  &acpi_gbl_fadt_gpe_device);
	}

	return_ACPI_STATUS (status);
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_lookup
 *
 * PARAMETERS:  prefix_node     - Search scope if name is not fully qualified
 *              Pathname        - Search pathname, in internal format
 *                                (as represented in the AML stream)
 *              Type            - Type associated with name
 *              interpreter_mode - IMODE_LOAD_PASS2 => add name if not found
 *              Flags           - Flags describing the search restrictions
 *              walk_state      - Current state of the walk
 *              return_node     - Where the Node is placed (if found
 *                                or created successfully)
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Find or enter the passed name in the name space.
 *              Log an error if name not found in Exec mode.
 *
 * MUTEX:       Assumes namespace is locked.
 *
 ******************************************************************************/

acpi_status
acpi_ns_lookup (
	union acpi_generic_state        *scope_info,
	char                            *pathname,
	acpi_object_type                type,
	acpi_interpreter_mode           interpreter_mode,
	u32                             flags,
	struct acpi_walk_state          *walk_state,
	struct acpi_namespace_node      **return_node)
{
	acpi_status                     status;
	char                            *path = pathname;
	struct acpi_namespace_node      *prefix_node;
	struct acpi_namespace_node      *current_node = NULL;
	struct acpi_namespace_node      *this_node = NULL;
	u32                             num_segments;
	u32                             num_carats;
	acpi_name                       simple_name;
	acpi_object_type                type_to_check_for;
	acpi_object_type                this_search_type;
	u32                             search_parent_flag = ACPI_NS_SEARCH_PARENT;
	u32                             local_flags = flags & ~(ACPI_NS_ERROR_IF_FOUND |
			   ACPI_NS_SEARCH_PARENT);


	ACPI_FUNCTION_TRACE ("ns_lookup");


	if (!return_node) {
		return_ACPI_STATUS (AE_BAD_PARAMETER);
	}

	acpi_gbl_ns_lookup_count++;
	*return_node = ACPI_ENTRY_NOT_FOUND;

	if (!acpi_gbl_root_node) {
		return_ACPI_STATUS (AE_NO_NAMESPACE);
	}

	/*
	 * Get the prefix scope.
	 * A null scope means use the root scope
	 */
	if ((!scope_info) ||
		(!scope_info->scope.node)) {
		ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
			"Null scope prefix, using root node (%p)\n",
			acpi_gbl_root_node));

		prefix_node = acpi_gbl_root_node;
	}
	else {
		prefix_node = scope_info->scope.node;
		if (ACPI_GET_DESCRIPTOR_TYPE (prefix_node) != ACPI_DESC_TYPE_NAMED) {
			ACPI_REPORT_ERROR (("ns_lookup: %p is not a namespace node [%s]\n",
					prefix_node, acpi_ut_get_descriptor_name (prefix_node)));
			return_ACPI_STATUS (AE_AML_INTERNAL);
		}

		/*
		 * This node might not be a actual "scope" node (such as a
		 * Device/Method, etc.)  It could be a Package or other object node.
		 * Backup up the tree to find the containing scope node.
		 */
		while (!acpi_ns_opens_scope (prefix_node->type) &&
				prefix_node->type != ACPI_TYPE_ANY) {
			prefix_node = acpi_ns_get_parent_node (prefix_node);
		}
	}

	/* Save type   TBD: may be no longer necessary */

	type_to_check_for = type;

	/*
	 * Begin examination of the actual pathname
	 */
	if (!pathname) {
		/* A Null name_path is allowed and refers to the root */

		num_segments = 0;
		this_node    = acpi_gbl_root_node;
		path     = "";

		ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
			"Null Pathname (Zero segments), Flags=%X\n", flags));
	}
	else {
		/*
		 * Name pointer is valid (and must be in internal name format)
		 *
		 * Check for scope prefixes:
		 *
		 * As represented in the AML stream, a namepath consists of an
		 * optional scope prefix followed by a name segment part.
		 *
		 * If present, the scope prefix is either a Root Prefix (in
		 * which case the name is fully qualified), or one or more
		 * Parent Prefixes (in which case the name's scope is relative
		 * to the current scope).
		 */
		if (*path == (u8) AML_ROOT_PREFIX) {
			/* Pathname is fully qualified, start from the root */

			this_node = acpi_gbl_root_node;
			search_parent_flag = ACPI_NS_NO_UPSEARCH;

			/* Point to name segment part */

			path++;

			ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
				"Path is absolute from root [%p]\n", this_node));
		}
		else {
			/* Pathname is relative to current scope, start there */

			ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
				"Searching relative to prefix scope [%4.4s] (%p)\n",
				acpi_ut_get_node_name (prefix_node), prefix_node));

			/*
			 * Handle multiple Parent Prefixes (carat) by just getting
			 * the parent node for each prefix instance.
			 */
			this_node = prefix_node;
			num_carats = 0;
			while (*path == (u8) AML_PARENT_PREFIX) {
				/* Name is fully qualified, no search rules apply */

				search_parent_flag = ACPI_NS_NO_UPSEARCH;
				/*
				 * Point past this prefix to the name segment
				 * part or the next Parent Prefix
				 */
				path++;

				/* Backup to the parent node */

				num_carats++;
				this_node = acpi_ns_get_parent_node (this_node);
				if (!this_node) {
					/* Current scope has no parent scope */

					ACPI_REPORT_ERROR (
						("ACPI path has too many parent prefixes (^) - reached beyond root node\n"));
					return_ACPI_STATUS (AE_NOT_FOUND);
				}
			}

			if (search_parent_flag == ACPI_NS_NO_UPSEARCH) {
				ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
					"Search scope is [%4.4s], path has %d carat(s)\n",
					acpi_ut_get_node_name (this_node), num_carats));
			}
		}

		/*
		 * Determine the number of ACPI name segments in this pathname.
		 *
		 * The segment part consists of either:
		 *  - A Null name segment (0)
		 *  - A dual_name_prefix followed by two 4-byte name segments
		 *  - A multi_name_prefix followed by a byte indicating the
		 *      number of segments and the segments themselves.
		 *  - A single 4-byte name segment
		 *
		 * Examine the name prefix opcode, if any, to determine the number of
		 * segments.
		 */
		switch (*path) {
		case 0:
			/*
			 * Null name after a root or parent prefixes. We already
			 * have the correct target node and there are no name segments.
			 */
			num_segments = 0;
			type = this_node->type;

			ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
				"Prefix-only Pathname (Zero name segments), Flags=%X\n",
				flags));
			break;

		case AML_DUAL_NAME_PREFIX:

			/* More than one name_seg, search rules do not apply */

			search_parent_flag = ACPI_NS_NO_UPSEARCH;

			/* Two segments, point to first name segment */

			num_segments = 2;
			path++;

			ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
				"Dual Pathname (2 segments, Flags=%X)\n", flags));
			break;

		case AML_MULTI_NAME_PREFIX_OP:

			/* More than one name_seg, search rules do not apply */

			search_parent_flag = ACPI_NS_NO_UPSEARCH;

			/* Extract segment count, point to first name segment */

			path++;
			num_segments = (u32) (u8) *path;
			path++;

			ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
				"Multi Pathname (%d Segments, Flags=%X) \n",
				num_segments, flags));
			break;

		default:
			/*
			 * Not a Null name, no Dual or Multi prefix, hence there is
			 * only one name segment and Pathname is already pointing to it.
			 */
			num_segments = 1;

			ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
				"Simple Pathname (1 segment, Flags=%X)\n", flags));
			break;
		}

		ACPI_DEBUG_EXEC (acpi_ns_print_pathname (num_segments, path));
	}


	/*
	 * Search namespace for each segment of the name.  Loop through and
	 * verify (or add to the namespace) each name segment.
	 *
	 * The object type is significant only at the last name
	 * segment.  (We don't care about the types along the path, only
	 * the type of the final target object.)
	 */
	this_search_type = ACPI_TYPE_ANY;
	current_node = this_node;
	while (num_segments && current_node) {
		num_segments--;
		if (!num_segments) {
			/*
			 * This is the last segment, enable typechecking
			 */
			this_search_type = type;

			/*
			 * Only allow automatic parent search (search rules) if the caller
			 * requested it AND we have a single, non-fully-qualified name_seg
			 */
			if ((search_parent_flag != ACPI_NS_NO_UPSEARCH) &&
				(flags & ACPI_NS_SEARCH_PARENT)) {
				local_flags |= ACPI_NS_SEARCH_PARENT;
			}

			/* Set error flag according to caller */

			if (flags & ACPI_NS_ERROR_IF_FOUND) {
				local_flags |= ACPI_NS_ERROR_IF_FOUND;
			}
		}

		/* Extract one ACPI name from the front of the pathname */

		ACPI_MOVE_32_TO_32 (&simple_name, path);

		/* Try to find the single (4 character) ACPI name */

		status = acpi_ns_search_and_enter (simple_name, walk_state, current_node,
				 interpreter_mode, this_search_type, local_flags, &this_node);
		if (ACPI_FAILURE (status)) {
			if (status == AE_NOT_FOUND) {
				/* Name not found in ACPI namespace */

				ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
					"Name [%4.4s] not found in scope [%4.4s] %p\n",
					(char *) &simple_name, (char *) &current_node->name,
					current_node));
			}

			*return_node = this_node;
			return_ACPI_STATUS (status);
		}

		/*
		 * Sanity typecheck of the target object:
		 *
		 * If 1) This is the last segment (num_segments == 0)
		 *    2) And we are looking for a specific type
		 *       (Not checking for TYPE_ANY)
		 *    3) Which is not an alias
		 *    4) Which is not a local type (TYPE_SCOPE)
		 *    5) And the type of target object is known (not TYPE_ANY)
		 *    6) And target object does not match what we are looking for
		 *
		 * Then we have a type mismatch.  Just warn and ignore it.
		 */
		if ((num_segments       == 0)                               &&
			(type_to_check_for  != ACPI_TYPE_ANY)                   &&
			(type_to_check_for  != ACPI_TYPE_LOCAL_ALIAS)           &&
			(type_to_check_for  != ACPI_TYPE_LOCAL_METHOD_ALIAS)    &&
			(type_to_check_for  != ACPI_TYPE_LOCAL_SCOPE)           &&
			(this_node->type    != ACPI_TYPE_ANY)                   &&
			(this_node->type    != type_to_check_for)) {
			/* Complain about a type mismatch */

			ACPI_REPORT_WARNING (
				("ns_lookup: Type mismatch on %4.4s (%s), searching for (%s)\n",
				(char *) &simple_name, acpi_ut_get_type_name (this_node->type),
				acpi_ut_get_type_name (type_to_check_for)));
		}

		/*
		 * If this is the last name segment and we are not looking for a
		 * specific type, but the type of found object is known, use that type
		 * to see if it opens a scope.
		 */
		if ((num_segments == 0) && (type == ACPI_TYPE_ANY)) {
			type = this_node->type;
		}

		/* Point to next name segment and make this node current */

		path += ACPI_NAME_SIZE;
		current_node = this_node;
	}

	/*
	 * Always check if we need to open a new scope
	 */
	if (!(flags & ACPI_NS_DONT_OPEN_SCOPE) && (walk_state)) {
		/*
		 * If entry is a type which opens a scope, push the new scope on the
		 * scope stack.
		 */
		if (acpi_ns_opens_scope (type)) {
			status = acpi_ds_scope_stack_push (this_node, type, walk_state);
			if (ACPI_FAILURE (status)) {
				return_ACPI_STATUS (status);
			}
		}
	}

	*return_node = this_node;
	return_ACPI_STATUS (AE_OK);
}