xref: /openbmc/linux/drivers/acpi/acpica/dspkginit.c (revision df687341)
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 - 2018, 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
19 ACPI_MODULE_NAME("dspkginit")
20 
21 /* Local prototypes */
22 static void
23 acpi_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 
54 acpi_status
55 acpi_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 
323 acpi_status
324 acpi_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 
380 static void
381 acpi_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