xref: /openbmc/linux/drivers/acpi/acpica/dspkginit.c (revision ba61bb17)
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->type == ACPI_TYPE_METHOD) {
156 				/*
157 				 * A method reference "looks" to the parser to be a method
158 				 * invocation, so we special case it here
159 				 */
160 				arg->common.aml_opcode = AML_INT_NAMEPATH_OP;
161 				status =
162 				    acpi_ds_build_internal_object(walk_state,
163 								  arg,
164 								  &obj_desc->
165 								  package.
166 								  elements[i]);
167 			} else {
168 				/* This package element is already built, just get it */
169 
170 				obj_desc->package.elements[i] =
171 				    ACPI_CAST_PTR(union acpi_operand_object,
172 						  arg->common.node);
173 			}
174 		} else {
175 			status =
176 			    acpi_ds_build_internal_object(walk_state, arg,
177 							  &obj_desc->package.
178 							  elements[i]);
179 			if (status == AE_NOT_FOUND) {
180 				ACPI_ERROR((AE_INFO, "%-48s",
181 					    "****DS namepath not found"));
182 			}
183 
184 			if (!module_level_code) {
185 				/*
186 				 * Initialize this package element. This function handles the
187 				 * resolution of named references within the package.
188 				 * Forward references from module-level code are deferred
189 				 * until all ACPI tables are loaded.
190 				 */
191 				acpi_ds_init_package_element(0,
192 							     obj_desc->package.
193 							     elements[i], NULL,
194 							     &obj_desc->package.
195 							     elements[i]);
196 			}
197 		}
198 
199 		if (*obj_desc_ptr) {
200 
201 			/* Existing package, get existing reference count */
202 
203 			reference_count =
204 			    (*obj_desc_ptr)->common.reference_count;
205 			if (reference_count > 1) {
206 
207 				/* Make new element ref count match original ref count */
208 				/* TBD: Probably need an acpi_ut_add_references function */
209 
210 				for (index = 0;
211 				     index < ((u32)reference_count - 1);
212 				     index++) {
213 					acpi_ut_add_reference((obj_desc->
214 							       package.
215 							       elements[i]));
216 				}
217 			}
218 		}
219 
220 		arg = arg->common.next;
221 	}
222 
223 	/* Check for match between num_elements and actual length of package_list */
224 
225 	if (arg) {
226 		/*
227 		 * num_elements was exhausted, but there are remaining elements in
228 		 * the package_list. Truncate the package to num_elements.
229 		 *
230 		 * Note: technically, this is an error, from ACPI spec: "It is an
231 		 * error for NumElements to be less than the number of elements in
232 		 * the PackageList". However, we just print a message and no
233 		 * exception is returned. This provides compatibility with other
234 		 * ACPI implementations. Some firmware implementations will alter
235 		 * the num_elements on the fly, possibly creating this type of
236 		 * ill-formed package object.
237 		 */
238 		while (arg) {
239 			/*
240 			 * We must delete any package elements that were created earlier
241 			 * and are not going to be used because of the package truncation.
242 			 */
243 			if (arg->common.node) {
244 				acpi_ut_remove_reference(ACPI_CAST_PTR
245 							 (union
246 							  acpi_operand_object,
247 							  arg->common.node));
248 				arg->common.node = NULL;
249 			}
250 
251 			/* Find out how many elements there really are */
252 
253 			i++;
254 			arg = arg->common.next;
255 		}
256 
257 		ACPI_INFO(("Actual Package length (%u) is larger than "
258 			   "NumElements field (%u), truncated",
259 			   i, element_count));
260 	} else if (i < element_count) {
261 		/*
262 		 * Arg list (elements) was exhausted, but we did not reach
263 		 * num_elements count.
264 		 *
265 		 * Note: this is not an error, the package is padded out
266 		 * with NULLs as per the ACPI specification.
267 		 */
268 		ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
269 				      "%s: Package List length (%u) smaller than NumElements "
270 				      "count (%u), padded with null elements\n",
271 				      ACPI_GET_FUNCTION_NAME, i,
272 				      element_count));
273 	}
274 
275 	/* Module-level packages will be resolved later */
276 
277 	if (!module_level_code) {
278 		obj_desc->package.flags |= AOPOBJ_DATA_VALID;
279 	}
280 
281 	op->common.node = ACPI_CAST_PTR(struct acpi_namespace_node, obj_desc);
282 	return_ACPI_STATUS(status);
283 }
284 
285 /*******************************************************************************
286  *
287  * FUNCTION:    acpi_ds_init_package_element
288  *
289  * PARAMETERS:  acpi_pkg_callback
290  *
291  * RETURN:      Status
292  *
293  * DESCRIPTION: Resolve a named reference element within a package object
294  *
295  ******************************************************************************/
296 
297 acpi_status
298 acpi_ds_init_package_element(u8 object_type,
299 			     union acpi_operand_object *source_object,
300 			     union acpi_generic_state *state, void *context)
301 {
302 	union acpi_operand_object **element_ptr;
303 
304 	ACPI_FUNCTION_TRACE(ds_init_package_element);
305 
306 	if (!source_object) {
307 		return_ACPI_STATUS(AE_OK);
308 	}
309 
310 	/*
311 	 * The following code is a bit of a hack to workaround a (current)
312 	 * limitation of the acpi_pkg_callback interface. We need a pointer
313 	 * to the location within the element array because a new object
314 	 * may be created and stored there.
315 	 */
316 	if (context) {
317 
318 		/* A direct call was made to this function */
319 
320 		element_ptr = (union acpi_operand_object **)context;
321 	} else {
322 		/* Call came from acpi_ut_walk_package_tree */
323 
324 		element_ptr = state->pkg.this_target_obj;
325 	}
326 
327 	/* We are only interested in reference objects/elements */
328 
329 	if (source_object->common.type == ACPI_TYPE_LOCAL_REFERENCE) {
330 
331 		/* Attempt to resolve the (named) reference to a namespace node */
332 
333 		acpi_ds_resolve_package_element(element_ptr);
334 	} else if (source_object->common.type == ACPI_TYPE_PACKAGE) {
335 		source_object->package.flags |= AOPOBJ_DATA_VALID;
336 	}
337 
338 	return_ACPI_STATUS(AE_OK);
339 }
340 
341 /*******************************************************************************
342  *
343  * FUNCTION:    acpi_ds_resolve_package_element
344  *
345  * PARAMETERS:  element_ptr         - Pointer to a reference object
346  *
347  * RETURN:      Possible new element is stored to the indirect element_ptr
348  *
349  * DESCRIPTION: Resolve a package element that is a reference to a named
350  *              object.
351  *
352  ******************************************************************************/
353 
354 static void
355 acpi_ds_resolve_package_element(union acpi_operand_object **element_ptr)
356 {
357 	acpi_status status;
358 	acpi_status status2;
359 	union acpi_generic_state scope_info;
360 	union acpi_operand_object *element = *element_ptr;
361 	struct acpi_namespace_node *resolved_node;
362 	struct acpi_namespace_node *original_node;
363 	char *external_path = "";
364 	acpi_object_type type;
365 
366 	ACPI_FUNCTION_TRACE(ds_resolve_package_element);
367 
368 	/* Check if reference element is already resolved */
369 
370 	if (element->reference.resolved) {
371 		ACPI_DEBUG_PRINT_RAW((ACPI_DB_PARSE,
372 				      "%s: Package element is already resolved\n",
373 				      ACPI_GET_FUNCTION_NAME));
374 
375 		return_VOID;
376 	}
377 
378 	/* Element must be a reference object of correct type */
379 
380 	scope_info.scope.node = element->reference.node;	/* Prefix node */
381 
382 	status = acpi_ns_lookup(&scope_info, (char *)element->reference.aml,
383 				ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE,
384 				ACPI_NS_SEARCH_PARENT | ACPI_NS_DONT_OPEN_SCOPE,
385 				NULL, &resolved_node);
386 	if (ACPI_FAILURE(status)) {
387 		if ((status == AE_NOT_FOUND)
388 		    && acpi_gbl_ignore_package_resolution_errors) {
389 			/*
390 			 * Optionally be silent about the NOT_FOUND case for the referenced
391 			 * name. Although this is potentially a serious problem,
392 			 * it can generate a lot of noise/errors on platforms whose
393 			 * firmware carries around a bunch of unused Package objects.
394 			 * To disable these errors, set this global to TRUE:
395 			 *     acpi_gbl_ignore_package_resolution_errors
396 			 *
397 			 * If the AML actually tries to use such a package, the unresolved
398 			 * element(s) will be replaced with NULL elements.
399 			 */
400 
401 			/* Referenced name not found, set the element to NULL */
402 
403 			acpi_ut_remove_reference(*element_ptr);
404 			*element_ptr = NULL;
405 			return_VOID;
406 		}
407 
408 		status2 = acpi_ns_externalize_name(ACPI_UINT32_MAX,
409 						   (char *)element->reference.
410 						   aml, NULL, &external_path);
411 
412 		ACPI_EXCEPTION((AE_INFO, status,
413 				"While resolving a named reference package element - %s",
414 				external_path));
415 		if (ACPI_SUCCESS(status2)) {
416 			ACPI_FREE(external_path);
417 		}
418 
419 		/* Could not resolve name, set the element to NULL */
420 
421 		acpi_ut_remove_reference(*element_ptr);
422 		*element_ptr = NULL;
423 		return_VOID;
424 	} else if (resolved_node->type == ACPI_TYPE_ANY) {
425 
426 		/* Named reference not resolved, return a NULL package element */
427 
428 		ACPI_ERROR((AE_INFO,
429 			    "Could not resolve named package element [%4.4s] in [%4.4s]",
430 			    resolved_node->name.ascii,
431 			    scope_info.scope.node->name.ascii));
432 		*element_ptr = NULL;
433 		return_VOID;
434 	}
435 
436 	/*
437 	 * Special handling for Alias objects. We need resolved_node to point
438 	 * to the Alias target. This effectively "resolves" the alias.
439 	 */
440 	if (resolved_node->type == ACPI_TYPE_LOCAL_ALIAS) {
441 		resolved_node = ACPI_CAST_PTR(struct acpi_namespace_node,
442 					      resolved_node->object);
443 	}
444 
445 	/* Update the reference object */
446 
447 	element->reference.resolved = TRUE;
448 	element->reference.node = resolved_node;
449 	type = element->reference.node->type;
450 
451 	/*
452 	 * Attempt to resolve the node to a value before we insert it into
453 	 * the package. If this is a reference to a common data type,
454 	 * resolve it immediately. According to the ACPI spec, package
455 	 * elements can only be "data objects" or method references.
456 	 * Attempt to resolve to an Integer, Buffer, String or Package.
457 	 * If cannot, return the named reference (for things like Devices,
458 	 * Methods, etc.) Buffer Fields and Fields will resolve to simple
459 	 * objects (int/buf/str/pkg).
460 	 *
461 	 * NOTE: References to things like Devices, Methods, Mutexes, etc.
462 	 * will remain as named references. This behavior is not described
463 	 * in the ACPI spec, but it appears to be an oversight.
464 	 */
465 	original_node = resolved_node;
466 	status = acpi_ex_resolve_node_to_value(&resolved_node, NULL);
467 	if (ACPI_FAILURE(status)) {
468 		return_VOID;
469 	}
470 
471 	switch (type) {
472 		/*
473 		 * These object types are a result of named references, so we will
474 		 * leave them as reference objects. In other words, these types
475 		 * have no intrinsic "value".
476 		 */
477 	case ACPI_TYPE_DEVICE:
478 	case ACPI_TYPE_THERMAL:
479 	case ACPI_TYPE_METHOD:
480 		break;
481 
482 	case ACPI_TYPE_MUTEX:
483 	case ACPI_TYPE_POWER:
484 	case ACPI_TYPE_PROCESSOR:
485 	case ACPI_TYPE_EVENT:
486 	case ACPI_TYPE_REGION:
487 
488 		/* acpi_ex_resolve_node_to_value gave these an extra reference */
489 
490 		acpi_ut_remove_reference(original_node->object);
491 		break;
492 
493 	default:
494 		/*
495 		 * For all other types - the node was resolved to an actual
496 		 * operand object with a value, return the object. Remove
497 		 * a reference on the existing object.
498 		 */
499 		acpi_ut_remove_reference(element);
500 		*element_ptr = (union acpi_operand_object *)resolved_node;
501 		break;
502 	}
503 
504 	return_VOID;
505 }
506