xref: /openbmc/linux/drivers/acpi/acpica/psparse.c (revision d3964221)
1 /******************************************************************************
2  *
3  * Module Name: psparse - Parser top level AML parse routines
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2017, Intel Corp.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions, and the following disclaimer,
16  *    without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  *    substantially similar to the "NO WARRANTY" disclaimer below
19  *    ("Disclaimer") and any redistribution must be conditioned upon
20  *    including a substantially similar Disclaimer requirement for further
21  *    binary redistribution.
22  * 3. Neither the names of the above-listed copyright holders nor the names
23  *    of any contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * Alternatively, this software may be distributed under the terms of the
27  * GNU General Public License ("GPL") version 2 as published by the Free
28  * Software Foundation.
29  *
30  * NO WARRANTY
31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41  * POSSIBILITY OF SUCH DAMAGES.
42  */
43 
44 /*
45  * Parse the AML and build an operation tree as most interpreters,
46  * like Perl, do. Parsing is done by hand rather than with a YACC
47  * generated parser to tightly constrain stack and dynamic memory
48  * usage. At the same time, parsing is kept flexible and the code
49  * fairly compact by parsing based on a list of AML opcode
50  * templates in aml_op_info[]
51  */
52 
53 #include <acpi/acpi.h>
54 #include "accommon.h"
55 #include "acparser.h"
56 #include "acdispat.h"
57 #include "amlcode.h"
58 #include "acinterp.h"
59 #include "acnamesp.h"
60 
61 #define _COMPONENT          ACPI_PARSER
62 ACPI_MODULE_NAME("psparse")
63 
64 /*******************************************************************************
65  *
66  * FUNCTION:    acpi_ps_get_opcode_size
67  *
68  * PARAMETERS:  opcode          - An AML opcode
69  *
70  * RETURN:      Size of the opcode, in bytes (1 or 2)
71  *
72  * DESCRIPTION: Get the size of the current opcode.
73  *
74  ******************************************************************************/
75 u32 acpi_ps_get_opcode_size(u32 opcode)
76 {
77 
78 	/* Extended (2-byte) opcode if > 255 */
79 
80 	if (opcode > 0x00FF) {
81 		return (2);
82 	}
83 
84 	/* Otherwise, just a single byte opcode */
85 
86 	return (1);
87 }
88 
89 /*******************************************************************************
90  *
91  * FUNCTION:    acpi_ps_peek_opcode
92  *
93  * PARAMETERS:  parser_state        - A parser state object
94  *
95  * RETURN:      Next AML opcode
96  *
97  * DESCRIPTION: Get next AML opcode (without incrementing AML pointer)
98  *
99  ******************************************************************************/
100 
101 u16 acpi_ps_peek_opcode(struct acpi_parse_state * parser_state)
102 {
103 	u8 *aml;
104 	u16 opcode;
105 
106 	aml = parser_state->aml;
107 	opcode = (u16) ACPI_GET8(aml);
108 
109 	if (opcode == AML_EXTENDED_PREFIX) {
110 
111 		/* Extended opcode, get the second opcode byte */
112 
113 		aml++;
114 		opcode = (u16) ((opcode << 8) | ACPI_GET8(aml));
115 	}
116 
117 	return (opcode);
118 }
119 
120 /*******************************************************************************
121  *
122  * FUNCTION:    acpi_ps_complete_this_op
123  *
124  * PARAMETERS:  walk_state      - Current State
125  *              op              - Op to complete
126  *
127  * RETURN:      Status
128  *
129  * DESCRIPTION: Perform any cleanup at the completion of an Op.
130  *
131  ******************************************************************************/
132 
133 acpi_status
134 acpi_ps_complete_this_op(struct acpi_walk_state *walk_state,
135 			 union acpi_parse_object *op)
136 {
137 	union acpi_parse_object *prev;
138 	union acpi_parse_object *next;
139 	const struct acpi_opcode_info *parent_info;
140 	union acpi_parse_object *replacement_op = NULL;
141 	acpi_status status = AE_OK;
142 
143 	ACPI_FUNCTION_TRACE_PTR(ps_complete_this_op, op);
144 
145 	/* Check for null Op, can happen if AML code is corrupt */
146 
147 	if (!op) {
148 		return_ACPI_STATUS(AE_OK);	/* OK for now */
149 	}
150 
151 	acpi_ex_stop_trace_opcode(op, walk_state);
152 
153 	/* Delete this op and the subtree below it if asked to */
154 
155 	if (((walk_state->parse_flags & ACPI_PARSE_TREE_MASK) !=
156 	     ACPI_PARSE_DELETE_TREE)
157 	    || (walk_state->op_info->class == AML_CLASS_ARGUMENT)) {
158 		return_ACPI_STATUS(AE_OK);
159 	}
160 
161 	/* Make sure that we only delete this subtree */
162 
163 	if (op->common.parent) {
164 		prev = op->common.parent->common.value.arg;
165 		if (!prev) {
166 
167 			/* Nothing more to do */
168 
169 			goto cleanup;
170 		}
171 
172 		/*
173 		 * Check if we need to replace the operator and its subtree
174 		 * with a return value op (placeholder op)
175 		 */
176 		parent_info =
177 		    acpi_ps_get_opcode_info(op->common.parent->common.
178 					    aml_opcode);
179 
180 		switch (parent_info->class) {
181 		case AML_CLASS_CONTROL:
182 
183 			break;
184 
185 		case AML_CLASS_CREATE:
186 			/*
187 			 * These opcodes contain term_arg operands. The current
188 			 * op must be replaced by a placeholder return op
189 			 */
190 			replacement_op =
191 			    acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP,
192 					     op->common.aml);
193 			if (!replacement_op) {
194 				status = AE_NO_MEMORY;
195 			}
196 			break;
197 
198 		case AML_CLASS_NAMED_OBJECT:
199 			/*
200 			 * These opcodes contain term_arg operands. The current
201 			 * op must be replaced by a placeholder return op
202 			 */
203 			if ((op->common.parent->common.aml_opcode ==
204 			     AML_REGION_OP)
205 			    || (op->common.parent->common.aml_opcode ==
206 				AML_DATA_REGION_OP)
207 			    || (op->common.parent->common.aml_opcode ==
208 				AML_BUFFER_OP)
209 			    || (op->common.parent->common.aml_opcode ==
210 				AML_PACKAGE_OP)
211 			    || (op->common.parent->common.aml_opcode ==
212 				AML_BANK_FIELD_OP)
213 			    || (op->common.parent->common.aml_opcode ==
214 				AML_VARIABLE_PACKAGE_OP)) {
215 				replacement_op =
216 				    acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP,
217 						     op->common.aml);
218 				if (!replacement_op) {
219 					status = AE_NO_MEMORY;
220 				}
221 			} else
222 			    if ((op->common.parent->common.aml_opcode ==
223 				 AML_NAME_OP)
224 				&& (walk_state->pass_number <=
225 				    ACPI_IMODE_LOAD_PASS2)) {
226 				if ((op->common.aml_opcode == AML_BUFFER_OP)
227 				    || (op->common.aml_opcode == AML_PACKAGE_OP)
228 				    || (op->common.aml_opcode ==
229 					AML_VARIABLE_PACKAGE_OP)) {
230 					replacement_op =
231 					    acpi_ps_alloc_op(op->common.
232 							     aml_opcode,
233 							     op->common.aml);
234 					if (!replacement_op) {
235 						status = AE_NO_MEMORY;
236 					} else {
237 						replacement_op->named.data =
238 						    op->named.data;
239 						replacement_op->named.length =
240 						    op->named.length;
241 					}
242 				}
243 			}
244 			break;
245 
246 		default:
247 
248 			replacement_op =
249 			    acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP,
250 					     op->common.aml);
251 			if (!replacement_op) {
252 				status = AE_NO_MEMORY;
253 			}
254 		}
255 
256 		/* We must unlink this op from the parent tree */
257 
258 		if (prev == op) {
259 
260 			/* This op is the first in the list */
261 
262 			if (replacement_op) {
263 				replacement_op->common.parent =
264 				    op->common.parent;
265 				replacement_op->common.value.arg = NULL;
266 				replacement_op->common.node = op->common.node;
267 				op->common.parent->common.value.arg =
268 				    replacement_op;
269 				replacement_op->common.next = op->common.next;
270 			} else {
271 				op->common.parent->common.value.arg =
272 				    op->common.next;
273 			}
274 		}
275 
276 		/* Search the parent list */
277 
278 		else
279 			while (prev) {
280 
281 				/* Traverse all siblings in the parent's argument list */
282 
283 				next = prev->common.next;
284 				if (next == op) {
285 					if (replacement_op) {
286 						replacement_op->common.parent =
287 						    op->common.parent;
288 						replacement_op->common.value.
289 						    arg = NULL;
290 						replacement_op->common.node =
291 						    op->common.node;
292 						prev->common.next =
293 						    replacement_op;
294 						replacement_op->common.next =
295 						    op->common.next;
296 						next = NULL;
297 					} else {
298 						prev->common.next =
299 						    op->common.next;
300 						next = NULL;
301 					}
302 				}
303 				prev = next;
304 			}
305 	}
306 
307 cleanup:
308 
309 	/* Now we can actually delete the subtree rooted at Op */
310 
311 	acpi_ps_delete_parse_tree(op);
312 	return_ACPI_STATUS(status);
313 }
314 
315 /*******************************************************************************
316  *
317  * FUNCTION:    acpi_ps_next_parse_state
318  *
319  * PARAMETERS:  walk_state          - Current state
320  *              op                  - Current parse op
321  *              callback_status     - Status from previous operation
322  *
323  * RETURN:      Status
324  *
325  * DESCRIPTION: Update the parser state based upon the return exception from
326  *              the parser callback.
327  *
328  ******************************************************************************/
329 
330 acpi_status
331 acpi_ps_next_parse_state(struct acpi_walk_state *walk_state,
332 			 union acpi_parse_object *op,
333 			 acpi_status callback_status)
334 {
335 	struct acpi_parse_state *parser_state = &walk_state->parser_state;
336 	acpi_status status = AE_CTRL_PENDING;
337 
338 	ACPI_FUNCTION_TRACE_PTR(ps_next_parse_state, op);
339 
340 	switch (callback_status) {
341 	case AE_CTRL_TERMINATE:
342 		/*
343 		 * A control method was terminated via a RETURN statement.
344 		 * The walk of this method is complete.
345 		 */
346 		parser_state->aml = parser_state->aml_end;
347 		status = AE_CTRL_TERMINATE;
348 		break;
349 
350 	case AE_CTRL_BREAK:
351 
352 		parser_state->aml = walk_state->aml_last_while;
353 		walk_state->control_state->common.value = FALSE;
354 		status = AE_CTRL_BREAK;
355 		break;
356 
357 	case AE_CTRL_CONTINUE:
358 
359 		parser_state->aml = walk_state->aml_last_while;
360 		status = AE_CTRL_CONTINUE;
361 		break;
362 
363 	case AE_CTRL_PENDING:
364 
365 		parser_state->aml = walk_state->aml_last_while;
366 		break;
367 
368 #if 0
369 	case AE_CTRL_SKIP:
370 
371 		parser_state->aml = parser_state->scope->parse_scope.pkg_end;
372 		status = AE_OK;
373 		break;
374 #endif
375 
376 	case AE_CTRL_TRUE:
377 		/*
378 		 * Predicate of an IF was true, and we are at the matching ELSE.
379 		 * Just close out this package
380 		 */
381 		parser_state->aml = acpi_ps_get_next_package_end(parser_state);
382 		status = AE_CTRL_PENDING;
383 		break;
384 
385 	case AE_CTRL_FALSE:
386 		/*
387 		 * Either an IF/WHILE Predicate was false or we encountered a BREAK
388 		 * opcode. In both cases, we do not execute the rest of the
389 		 * package;  We simply close out the parent (finishing the walk of
390 		 * this branch of the tree) and continue execution at the parent
391 		 * level.
392 		 */
393 		parser_state->aml = parser_state->scope->parse_scope.pkg_end;
394 
395 		/* In the case of a BREAK, just force a predicate (if any) to FALSE */
396 
397 		walk_state->control_state->common.value = FALSE;
398 		status = AE_CTRL_END;
399 		break;
400 
401 	case AE_CTRL_TRANSFER:
402 
403 		/* A method call (invocation) -- transfer control */
404 
405 		status = AE_CTRL_TRANSFER;
406 		walk_state->prev_op = op;
407 		walk_state->method_call_op = op;
408 		walk_state->method_call_node =
409 		    (op->common.value.arg)->common.node;
410 
411 		/* Will return value (if any) be used by the caller? */
412 
413 		walk_state->return_used =
414 		    acpi_ds_is_result_used(op, walk_state);
415 		break;
416 
417 	default:
418 
419 		status = callback_status;
420 		if ((callback_status & AE_CODE_MASK) == AE_CODE_CONTROL) {
421 			status = AE_OK;
422 		}
423 		break;
424 	}
425 
426 	return_ACPI_STATUS(status);
427 }
428 
429 /*******************************************************************************
430  *
431  * FUNCTION:    acpi_ps_parse_aml
432  *
433  * PARAMETERS:  walk_state      - Current state
434  *
435  *
436  * RETURN:      Status
437  *
438  * DESCRIPTION: Parse raw AML and return a tree of ops
439  *
440  ******************************************************************************/
441 
442 acpi_status acpi_ps_parse_aml(struct acpi_walk_state *walk_state)
443 {
444 	acpi_status status;
445 	struct acpi_thread_state *thread;
446 	struct acpi_thread_state *prev_walk_list = acpi_gbl_current_walk_list;
447 	struct acpi_walk_state *previous_walk_state;
448 
449 	ACPI_FUNCTION_TRACE(ps_parse_aml);
450 
451 	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
452 			  "Entered with WalkState=%p Aml=%p size=%X\n",
453 			  walk_state, walk_state->parser_state.aml,
454 			  walk_state->parser_state.aml_size));
455 
456 	if (!walk_state->parser_state.aml) {
457 		return_ACPI_STATUS(AE_NULL_OBJECT);
458 	}
459 
460 	/* Create and initialize a new thread state */
461 
462 	thread = acpi_ut_create_thread_state();
463 	if (!thread) {
464 		if (walk_state->method_desc) {
465 
466 			/* Executing a control method - additional cleanup */
467 
468 			acpi_ds_terminate_control_method(walk_state->
469 							 method_desc,
470 							 walk_state);
471 		}
472 
473 		acpi_ds_delete_walk_state(walk_state);
474 		return_ACPI_STATUS(AE_NO_MEMORY);
475 	}
476 
477 	walk_state->thread = thread;
478 
479 	/*
480 	 * If executing a method, the starting sync_level is this method's
481 	 * sync_level
482 	 */
483 	if (walk_state->method_desc) {
484 		walk_state->thread->current_sync_level =
485 		    walk_state->method_desc->method.sync_level;
486 	}
487 
488 	acpi_ds_push_walk_state(walk_state, thread);
489 
490 	/*
491 	 * This global allows the AML debugger to get a handle to the currently
492 	 * executing control method.
493 	 */
494 	acpi_gbl_current_walk_list = thread;
495 
496 	/*
497 	 * Execute the walk loop as long as there is a valid Walk State. This
498 	 * handles nested control method invocations without recursion.
499 	 */
500 	ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "State=%p\n", walk_state));
501 
502 	status = AE_OK;
503 	while (walk_state) {
504 		if (ACPI_SUCCESS(status)) {
505 			/*
506 			 * The parse_loop executes AML until the method terminates
507 			 * or calls another method.
508 			 */
509 			status = acpi_ps_parse_loop(walk_state);
510 		}
511 
512 		ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
513 				  "Completed one call to walk loop, %s State=%p\n",
514 				  acpi_format_exception(status), walk_state));
515 
516 		if (status == AE_CTRL_TRANSFER) {
517 			/*
518 			 * A method call was detected.
519 			 * Transfer control to the called control method
520 			 */
521 			status =
522 			    acpi_ds_call_control_method(thread, walk_state,
523 							NULL);
524 			if (ACPI_FAILURE(status)) {
525 				status =
526 				    acpi_ds_method_error(status, walk_state);
527 			}
528 
529 			/*
530 			 * If the transfer to the new method method call worked
531 			 *, a new walk state was created -- get it
532 			 */
533 			walk_state = acpi_ds_get_current_walk_state(thread);
534 			continue;
535 		} else if (status == AE_CTRL_TERMINATE) {
536 			status = AE_OK;
537 		} else if ((status != AE_OK) && (walk_state->method_desc)) {
538 
539 			/* Either the method parse or actual execution failed */
540 
541 			acpi_ex_exit_interpreter();
542 			if (status == AE_ABORT_METHOD) {
543 				acpi_ns_print_node_pathname(walk_state->
544 							    method_node,
545 							    "Method aborted:");
546 				acpi_os_printf("\n");
547 			} else {
548 				ACPI_ERROR_METHOD
549 				    ("Method parse/execution failed",
550 				     walk_state->method_node, NULL, status);
551 			}
552 			acpi_ex_enter_interpreter();
553 
554 			/* Check for possible multi-thread reentrancy problem */
555 
556 			if ((status == AE_ALREADY_EXISTS) &&
557 			    (!(walk_state->method_desc->method.info_flags &
558 			       ACPI_METHOD_SERIALIZED))) {
559 				/*
560 				 * Method is not serialized and tried to create an object
561 				 * twice. The probable cause is that the method cannot
562 				 * handle reentrancy. Mark as "pending serialized" now, and
563 				 * then mark "serialized" when the last thread exits.
564 				 */
565 				walk_state->method_desc->method.info_flags |=
566 				    ACPI_METHOD_SERIALIZED_PENDING;
567 			}
568 		}
569 
570 		/* We are done with this walk, move on to the parent if any */
571 
572 		walk_state = acpi_ds_pop_walk_state(thread);
573 
574 		/* Reset the current scope to the beginning of scope stack */
575 
576 		acpi_ds_scope_stack_clear(walk_state);
577 
578 		/*
579 		 * If we just returned from the execution of a control method or if we
580 		 * encountered an error during the method parse phase, there's lots of
581 		 * cleanup to do
582 		 */
583 		if (((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) ==
584 		     ACPI_PARSE_EXECUTE &&
585 		     !(walk_state->parse_flags & ACPI_PARSE_MODULE_LEVEL)) ||
586 		    (ACPI_FAILURE(status))) {
587 			acpi_ds_terminate_control_method(walk_state->
588 							 method_desc,
589 							 walk_state);
590 		}
591 
592 		/* Delete this walk state and all linked control states */
593 
594 		acpi_ps_cleanup_scope(&walk_state->parser_state);
595 		previous_walk_state = walk_state;
596 
597 		ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
598 				  "ReturnValue=%p, ImplicitValue=%p State=%p\n",
599 				  walk_state->return_desc,
600 				  walk_state->implicit_return_obj, walk_state));
601 
602 		/* Check if we have restarted a preempted walk */
603 
604 		walk_state = acpi_ds_get_current_walk_state(thread);
605 		if (walk_state) {
606 			if (ACPI_SUCCESS(status)) {
607 				/*
608 				 * There is another walk state, restart it.
609 				 * If the method return value is not used by the parent,
610 				 * The object is deleted
611 				 */
612 				if (!previous_walk_state->return_desc) {
613 					/*
614 					 * In slack mode execution, if there is no return value
615 					 * we should implicitly return zero (0) as a default value.
616 					 */
617 					if (acpi_gbl_enable_interpreter_slack &&
618 					    !previous_walk_state->
619 					    implicit_return_obj) {
620 						previous_walk_state->
621 						    implicit_return_obj =
622 						    acpi_ut_create_integer_object
623 						    ((u64) 0);
624 						if (!previous_walk_state->
625 						    implicit_return_obj) {
626 							return_ACPI_STATUS
627 							    (AE_NO_MEMORY);
628 						}
629 					}
630 
631 					/* Restart the calling control method */
632 
633 					status =
634 					    acpi_ds_restart_control_method
635 					    (walk_state,
636 					     previous_walk_state->
637 					     implicit_return_obj);
638 				} else {
639 					/*
640 					 * We have a valid return value, delete any implicit
641 					 * return value.
642 					 */
643 					acpi_ds_clear_implicit_return
644 					    (previous_walk_state);
645 
646 					status =
647 					    acpi_ds_restart_control_method
648 					    (walk_state,
649 					     previous_walk_state->return_desc);
650 				}
651 				if (ACPI_SUCCESS(status)) {
652 					walk_state->walk_type |=
653 					    ACPI_WALK_METHOD_RESTART;
654 				}
655 			} else {
656 				/* On error, delete any return object or implicit return */
657 
658 				acpi_ut_remove_reference(previous_walk_state->
659 							 return_desc);
660 				acpi_ds_clear_implicit_return
661 				    (previous_walk_state);
662 			}
663 		}
664 
665 		/*
666 		 * Just completed a 1st-level method, save the final internal return
667 		 * value (if any)
668 		 */
669 		else if (previous_walk_state->caller_return_desc) {
670 			if (previous_walk_state->implicit_return_obj) {
671 				*(previous_walk_state->caller_return_desc) =
672 				    previous_walk_state->implicit_return_obj;
673 			} else {
674 				/* NULL if no return value */
675 
676 				*(previous_walk_state->caller_return_desc) =
677 				    previous_walk_state->return_desc;
678 			}
679 		} else {
680 			if (previous_walk_state->return_desc) {
681 
682 				/* Caller doesn't want it, must delete it */
683 
684 				acpi_ut_remove_reference(previous_walk_state->
685 							 return_desc);
686 			}
687 			if (previous_walk_state->implicit_return_obj) {
688 
689 				/* Caller doesn't want it, must delete it */
690 
691 				acpi_ut_remove_reference(previous_walk_state->
692 							 implicit_return_obj);
693 			}
694 		}
695 
696 		acpi_ds_delete_walk_state(previous_walk_state);
697 	}
698 
699 	/* Normal exit */
700 
701 	acpi_ex_release_all_mutexes(thread);
702 	acpi_ut_delete_generic_state(ACPI_CAST_PTR
703 				     (union acpi_generic_state, thread));
704 	acpi_gbl_current_walk_list = prev_walk_list;
705 	return_ACPI_STATUS(status);
706 }
707