1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2/******************************************************************************
3 *
4 * Module Name: dspkginit - Completion of deferred package initialization
5 *
6 * Copyright (C) 2000 - 2023, Intel Corp.
7 *
8 *****************************************************************************/
9
10#include <acpi/acpi.h>
11#include "accommon.h"
12#include "acnamesp.h"
13#include "amlcode.h"
14#include "acdispat.h"
15#include "acinterp.h"
16#include "acparser.h"
17
18#define _COMPONENT          ACPI_NAMESPACE
19ACPI_MODULE_NAME("dspkginit")
20
21/* Local prototypes */
22static void
23acpi_ds_resolve_package_element(union acpi_operand_object **element);
24
25/*******************************************************************************
26 *
27 * FUNCTION:    acpi_ds_build_internal_package_obj
28 *
29 * PARAMETERS:  walk_state      - Current walk state
30 *              op              - Parser object to be translated
31 *              element_count   - Number of elements in the package - this is
32 *                                the num_elements argument to Package()
33 *              obj_desc_ptr    - Where the ACPI internal object is returned
34 *
35 * RETURN:      Status
36 *
37 * DESCRIPTION: Translate a parser Op package object to the equivalent
38 *              namespace object
39 *
40 * NOTE: The number of elements in the package will be always be the num_elements
41 * count, regardless of the number of elements in the package list. If
42 * num_elements is smaller, only that many package list elements are used.
43 * if num_elements is larger, the Package object is padded out with
44 * objects of type Uninitialized (as per ACPI spec.)
45 *
46 * Even though the ASL compilers do not allow num_elements to be smaller
47 * than the Package list length (for the fixed length package opcode), some
48 * BIOS code modifies the AML on the fly to adjust the num_elements, and
49 * this code compensates for that. This also provides compatibility with
50 * other AML interpreters.
51 *
52 ******************************************************************************/
53
54acpi_status
55acpi_ds_build_internal_package_obj(struct acpi_walk_state *walk_state,
56				   union acpi_parse_object *op,
57				   u32 element_count,
58				   union acpi_operand_object **obj_desc_ptr)
59{
60	union acpi_parse_object *arg;
61	union acpi_parse_object *parent;
62	union acpi_operand_object *obj_desc = NULL;
63	acpi_status status = AE_OK;
64	u8 module_level_code = FALSE;
65	u16 reference_count;
66	u32 index;
67	u32 i;
68
69	ACPI_FUNCTION_TRACE(ds_build_internal_package_obj);
70
71	/* Check if we are executing module level code */
72
73	if (walk_state->parse_flags & ACPI_PARSE_MODULE_LEVEL) {
74		module_level_code = TRUE;
75	}
76
77	/* Find the parent of a possibly nested package */
78
79	parent = op->common.parent;
80	while ((parent->common.aml_opcode == AML_PACKAGE_OP) ||
81	       (parent->common.aml_opcode == AML_VARIABLE_PACKAGE_OP)) {
82		parent = parent->common.parent;
83	}
84
85	/*
86	 * If we are evaluating a Named package object of the form:
87	 *      Name (xxxx, Package)
88	 * the package object already exists, otherwise it must be created.
89	 */
90	obj_desc = *obj_desc_ptr;
91	if (!obj_desc) {
92		obj_desc = acpi_ut_create_internal_object(ACPI_TYPE_PACKAGE);
93		*obj_desc_ptr = obj_desc;
94		if (!obj_desc) {
95			return_ACPI_STATUS(AE_NO_MEMORY);
96		}
97
98		obj_desc->package.node = parent->common.node;
99	}
100
101	if (obj_desc->package.flags & AOPOBJ_DATA_VALID) {	/* Just in case */
102		return_ACPI_STATUS(AE_OK);
103	}
104
105	/*
106	 * Allocate the element array (array of pointers to the individual
107	 * objects) if necessary. the count is based on the num_elements
108	 * parameter. Add an extra pointer slot so that the list is always
109	 * null terminated.
110	 */
111	if (!obj_desc->package.elements) {
112		obj_desc->package.elements = ACPI_ALLOCATE_ZEROED(((acpi_size)
113								   element_count
114								   +
115								   1) *
116								  sizeof(void
117									 *));
118
119		if (!obj_desc->package.elements) {
120			acpi_ut_delete_object_desc(obj_desc);
121			return_ACPI_STATUS(AE_NO_MEMORY);
122		}
123
124		obj_desc->package.count = element_count;
125	}
126
127	/* First arg is element count. Second arg begins the initializer list */
128
129	arg = op->common.value.arg;
130	arg = arg->common.next;
131
132	/*
133	 * If we are executing module-level code, we will defer the
134	 * full resolution of the package elements in order to support
135	 * forward references from the elements. This provides
136	 * compatibility with other ACPI implementations.
137	 */
138	if (module_level_code) {
139		obj_desc->package.aml_start = walk_state->aml;
140		obj_desc->package.aml_length = 0;
141
142		ACPI_DEBUG_PRINT_RAW((ACPI_DB_PARSE,
143				      "%s: Deferring resolution of Package elements\n",
144				      ACPI_GET_FUNCTION_NAME));
145	}
146
147	/*
148	 * Initialize the elements of the package, up to the num_elements count.
149	 * Package is automatically padded with uninitialized (NULL) elements
150	 * if num_elements is greater than the package list length. Likewise,
151	 * Package is truncated if num_elements is less than the list length.
152	 */
153	for (i = 0; arg && (i < element_count); i++) {
154		if (arg->common.aml_opcode == AML_INT_RETURN_VALUE_OP) {
155			if (!arg->common.node) {
156				/*
157				 * This is the case where an expression has returned a value.
158				 * The use of expressions (term_args) within individual
159				 * package elements is not supported by the AML interpreter,
160				 * even though the ASL grammar supports it. Example:
161				 *
162				 *      Name (INT1, 0x1234)
163				 *
164				 *      Name (PKG3, Package () {
165				 *          Add (INT1, 0xAAAA0000)
166				 *      })
167				 *
168				 *  1) No known AML interpreter supports this type of construct
169				 *  2) This fixes a fault if the construct is encountered
170				 */
171				ACPI_EXCEPTION((AE_INFO, AE_SUPPORT,
172						"Expressions within package elements are not supported"));
173
174				/* Cleanup the return object, it is not needed */
175
176				acpi_ut_remove_reference(walk_state->results->
177							 results.obj_desc[0]);
178				return_ACPI_STATUS(AE_SUPPORT);
179			}
180
181			if (arg->common.node->type == ACPI_TYPE_METHOD) {
182				/*
183				 * A method reference "looks" to the parser to be a method
184				 * invocation, so we special case it here
185				 */
186				arg->common.aml_opcode = AML_INT_NAMEPATH_OP;
187				status =
188				    acpi_ds_build_internal_object(walk_state,
189								  arg,
190								  &obj_desc->
191								  package.
192								  elements[i]);
193			} else {
194				/* This package element is already built, just get it */
195
196				obj_desc->package.elements[i] =
197				    ACPI_CAST_PTR(union acpi_operand_object,
198						  arg->common.node);
199			}
200		} else {
201			status =
202			    acpi_ds_build_internal_object(walk_state, arg,
203							  &obj_desc->package.
204							  elements[i]);
205			if (status == AE_NOT_FOUND) {
206				ACPI_ERROR((AE_INFO, "%-48s",
207					    "****DS namepath not found"));
208			}
209
210			if (!module_level_code) {
211				/*
212				 * Initialize this package element. This function handles the
213				 * resolution of named references within the package.
214				 * Forward references from module-level code are deferred
215				 * until all ACPI tables are loaded.
216				 */
217				acpi_ds_init_package_element(0,
218							     obj_desc->package.
219							     elements[i], NULL,
220							     &obj_desc->package.
221							     elements[i]);
222			}
223		}
224
225		if (*obj_desc_ptr) {
226
227			/* Existing package, get existing reference count */
228
229			reference_count =
230			    (*obj_desc_ptr)->common.reference_count;
231			if (reference_count > 1) {
232
233				/* Make new element ref count match original ref count */
234				/* TBD: Probably need an acpi_ut_add_references function */
235
236				for (index = 0;
237				     index < ((u32)reference_count - 1);
238				     index++) {
239					acpi_ut_add_reference((obj_desc->
240							       package.
241							       elements[i]));
242				}
243			}
244		}
245
246		arg = arg->common.next;
247	}
248
249	/* Check for match between num_elements and actual length of package_list */
250
251	if (arg) {
252		/*
253		 * num_elements was exhausted, but there are remaining elements in
254		 * the package_list. Truncate the package to num_elements.
255		 *
256		 * Note: technically, this is an error, from ACPI spec: "It is an
257		 * error for NumElements to be less than the number of elements in
258		 * the PackageList". However, we just print a message and no
259		 * exception is returned. This provides compatibility with other
260		 * ACPI implementations. Some firmware implementations will alter
261		 * the num_elements on the fly, possibly creating this type of
262		 * ill-formed package object.
263		 */
264		while (arg) {
265			/*
266			 * We must delete any package elements that were created earlier
267			 * and are not going to be used because of the package truncation.
268			 */
269			if (arg->common.node) {
270				acpi_ut_remove_reference(ACPI_CAST_PTR
271							 (union
272							  acpi_operand_object,
273							  arg->common.node));
274				arg->common.node = NULL;
275			}
276
277			/* Find out how many elements there really are */
278
279			i++;
280			arg = arg->common.next;
281		}
282
283		ACPI_INFO(("Actual Package length (%u) is larger than "
284			   "NumElements field (%u), truncated",
285			   i, element_count));
286	} else if (i < element_count) {
287		/*
288		 * Arg list (elements) was exhausted, but we did not reach
289		 * num_elements count.
290		 *
291		 * Note: this is not an error, the package is padded out
292		 * with NULLs as per the ACPI specification.
293		 */
294		ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
295				      "%s: Package List length (%u) smaller than NumElements "
296				      "count (%u), padded with null elements\n",
297				      ACPI_GET_FUNCTION_NAME, i,
298				      element_count));
299	}
300
301	/* Module-level packages will be resolved later */
302
303	if (!module_level_code) {
304		obj_desc->package.flags |= AOPOBJ_DATA_VALID;
305	}
306
307	op->common.node = ACPI_CAST_PTR(struct acpi_namespace_node, obj_desc);
308	return_ACPI_STATUS(status);
309}
310
311/*******************************************************************************
312 *
313 * FUNCTION:    acpi_ds_init_package_element
314 *
315 * PARAMETERS:  acpi_pkg_callback
316 *
317 * RETURN:      Status
318 *
319 * DESCRIPTION: Resolve a named reference element within a package object
320 *
321 ******************************************************************************/
322
323acpi_status
324acpi_ds_init_package_element(u8 object_type,
325			     union acpi_operand_object *source_object,
326			     union acpi_generic_state *state, void *context)
327{
328	union acpi_operand_object **element_ptr;
329
330	ACPI_FUNCTION_TRACE(ds_init_package_element);
331
332	if (!source_object) {
333		return_ACPI_STATUS(AE_OK);
334	}
335
336	/*
337	 * The following code is a bit of a hack to workaround a (current)
338	 * limitation of the acpi_pkg_callback interface. We need a pointer
339	 * to the location within the element array because a new object
340	 * may be created and stored there.
341	 */
342	if (context) {
343
344		/* A direct call was made to this function */
345
346		element_ptr = (union acpi_operand_object **)context;
347	} else {
348		/* Call came from acpi_ut_walk_package_tree */
349
350		element_ptr = state->pkg.this_target_obj;
351	}
352
353	/* We are only interested in reference objects/elements */
354
355	if (source_object->common.type == ACPI_TYPE_LOCAL_REFERENCE) {
356
357		/* Attempt to resolve the (named) reference to a namespace node */
358
359		acpi_ds_resolve_package_element(element_ptr);
360	} else if (source_object->common.type == ACPI_TYPE_PACKAGE) {
361		source_object->package.flags |= AOPOBJ_DATA_VALID;
362	}
363
364	return_ACPI_STATUS(AE_OK);
365}
366
367/*******************************************************************************
368 *
369 * FUNCTION:    acpi_ds_resolve_package_element
370 *
371 * PARAMETERS:  element_ptr         - Pointer to a reference object
372 *
373 * RETURN:      Possible new element is stored to the indirect element_ptr
374 *
375 * DESCRIPTION: Resolve a package element that is a reference to a named
376 *              object.
377 *
378 ******************************************************************************/
379
380static void
381acpi_ds_resolve_package_element(union acpi_operand_object **element_ptr)
382{
383	acpi_status status;
384	acpi_status status2;
385	union acpi_generic_state scope_info;
386	union acpi_operand_object *element = *element_ptr;
387	struct acpi_namespace_node *resolved_node;
388	struct acpi_namespace_node *original_node;
389	char *external_path = "";
390	acpi_object_type type;
391
392	ACPI_FUNCTION_TRACE(ds_resolve_package_element);
393
394	/* Check if reference element is already resolved */
395
396	if (element->reference.resolved) {
397		ACPI_DEBUG_PRINT_RAW((ACPI_DB_PARSE,
398				      "%s: Package element is already resolved\n",
399				      ACPI_GET_FUNCTION_NAME));
400
401		return_VOID;
402	}
403
404	/* Element must be a reference object of correct type */
405
406	scope_info.scope.node = element->reference.node;	/* Prefix node */
407
408	status = acpi_ns_lookup(&scope_info, (char *)element->reference.aml,
409				ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE,
410				ACPI_NS_SEARCH_PARENT | ACPI_NS_DONT_OPEN_SCOPE,
411				NULL, &resolved_node);
412	if (ACPI_FAILURE(status)) {
413		if ((status == AE_NOT_FOUND)
414		    && acpi_gbl_ignore_package_resolution_errors) {
415			/*
416			 * Optionally be silent about the NOT_FOUND case for the referenced
417			 * name. Although this is potentially a serious problem,
418			 * it can generate a lot of noise/errors on platforms whose
419			 * firmware carries around a bunch of unused Package objects.
420			 * To disable these errors, set this global to TRUE:
421			 *     acpi_gbl_ignore_package_resolution_errors
422			 *
423			 * If the AML actually tries to use such a package, the unresolved
424			 * element(s) will be replaced with NULL elements.
425			 */
426
427			/* Referenced name not found, set the element to NULL */
428
429			acpi_ut_remove_reference(*element_ptr);
430			*element_ptr = NULL;
431			return_VOID;
432		}
433
434		status2 = acpi_ns_externalize_name(ACPI_UINT32_MAX,
435						   (char *)element->reference.
436						   aml, NULL, &external_path);
437
438		ACPI_EXCEPTION((AE_INFO, status,
439				"While resolving a named reference package element - %s",
440				external_path));
441		if (ACPI_SUCCESS(status2)) {
442			ACPI_FREE(external_path);
443		}
444
445		/* Could not resolve name, set the element to NULL */
446
447		acpi_ut_remove_reference(*element_ptr);
448		*element_ptr = NULL;
449		return_VOID;
450	} else if (resolved_node->type == ACPI_TYPE_ANY) {
451
452		/* Named reference not resolved, return a NULL package element */
453
454		ACPI_ERROR((AE_INFO,
455			    "Could not resolve named package element [%4.4s] in [%4.4s]",
456			    resolved_node->name.ascii,
457			    scope_info.scope.node->name.ascii));
458		*element_ptr = NULL;
459		return_VOID;
460	}
461
462	/*
463	 * Special handling for Alias objects. We need resolved_node to point
464	 * to the Alias target. This effectively "resolves" the alias.
465	 */
466	if (resolved_node->type == ACPI_TYPE_LOCAL_ALIAS) {
467		resolved_node = ACPI_CAST_PTR(struct acpi_namespace_node,
468					      resolved_node->object);
469	}
470
471	/* Update the reference object */
472
473	element->reference.resolved = TRUE;
474	element->reference.node = resolved_node;
475	type = element->reference.node->type;
476
477	/*
478	 * Attempt to resolve the node to a value before we insert it into
479	 * the package. If this is a reference to a common data type,
480	 * resolve it immediately. According to the ACPI spec, package
481	 * elements can only be "data objects" or method references.
482	 * Attempt to resolve to an Integer, Buffer, String or Package.
483	 * If cannot, return the named reference (for things like Devices,
484	 * Methods, etc.) Buffer Fields and Fields will resolve to simple
485	 * objects (int/buf/str/pkg).
486	 *
487	 * NOTE: References to things like Devices, Methods, Mutexes, etc.
488	 * will remain as named references. This behavior is not described
489	 * in the ACPI spec, but it appears to be an oversight.
490	 */
491	original_node = resolved_node;
492	status = acpi_ex_resolve_node_to_value(&resolved_node, NULL);
493	if (ACPI_FAILURE(status)) {
494		return_VOID;
495	}
496
497	switch (type) {
498		/*
499		 * These object types are a result of named references, so we will
500		 * leave them as reference objects. In other words, these types
501		 * have no intrinsic "value".
502		 */
503	case ACPI_TYPE_DEVICE:
504	case ACPI_TYPE_THERMAL:
505	case ACPI_TYPE_METHOD:
506		break;
507
508	case ACPI_TYPE_MUTEX:
509	case ACPI_TYPE_POWER:
510	case ACPI_TYPE_PROCESSOR:
511	case ACPI_TYPE_EVENT:
512	case ACPI_TYPE_REGION:
513
514		/* acpi_ex_resolve_node_to_value gave these an extra reference */
515
516		acpi_ut_remove_reference(original_node->object);
517		break;
518
519	default:
520		/*
521		 * For all other types - the node was resolved to an actual
522		 * operand object with a value, return the object. Remove
523		 * a reference on the existing object.
524		 */
525		acpi_ut_remove_reference(element);
526		*element_ptr = (union acpi_operand_object *)resolved_node;
527		break;
528	}
529
530	return_VOID;
531}
532