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1da177e4 LT |
1 | /****************************************************************************** |
2 | * | |
3 | * Module Name: dsmethod - Parser/Interpreter interface - control method parsing | |
4 | * | |
5 | *****************************************************************************/ | |
6 | ||
7 | /* | |
4a90c7e8 | 8 | * Copyright (C) 2000 - 2006, R. Byron Moore |
1da177e4 LT |
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 | ||
1da177e4 LT |
44 | #include <acpi/acpi.h> |
45 | #include <acpi/acparser.h> | |
46 | #include <acpi/amlcode.h> | |
47 | #include <acpi/acdispat.h> | |
48 | #include <acpi/acinterp.h> | |
49 | #include <acpi/acnamesp.h> | |
defba1d8 | 50 | #include <acpi/acdisasm.h> |
1da177e4 | 51 | |
1da177e4 | 52 | #define _COMPONENT ACPI_DISPATCHER |
4be44fcd | 53 | ACPI_MODULE_NAME("dsmethod") |
1da177e4 | 54 | |
967440e3 BM |
55 | /* Local prototypes */ |
56 | static acpi_status | |
57 | acpi_ds_create_method_mutex(union acpi_operand_object *method_desc); | |
58 | ||
defba1d8 BM |
59 | /******************************************************************************* |
60 | * | |
61 | * FUNCTION: acpi_ds_method_error | |
62 | * | |
63 | * PARAMETERS: Status - Execution status | |
64 | * walk_state - Current state | |
65 | * | |
66 | * RETURN: Status | |
67 | * | |
68 | * DESCRIPTION: Called on method error. Invoke the global exception handler if | |
69 | * present, dump the method data if the disassembler is configured | |
70 | * | |
71 | * Note: Allows the exception handler to change the status code | |
72 | * | |
73 | ******************************************************************************/ | |
967440e3 | 74 | |
defba1d8 BM |
75 | acpi_status |
76 | acpi_ds_method_error(acpi_status status, struct acpi_walk_state *walk_state) | |
77 | { | |
78 | ACPI_FUNCTION_ENTRY(); | |
79 | ||
80 | /* Ignore AE_OK and control exception codes */ | |
81 | ||
82 | if (ACPI_SUCCESS(status) || (status & AE_CODE_CONTROL)) { | |
83 | return (status); | |
84 | } | |
85 | ||
86 | /* Invoke the global exception handler */ | |
87 | ||
88 | if (acpi_gbl_exception_handler) { | |
52fc0b02 | 89 | |
defba1d8 BM |
90 | /* Exit the interpreter, allow handler to execute methods */ |
91 | ||
92 | acpi_ex_exit_interpreter(); | |
93 | ||
94 | /* | |
95 | * Handler can map the exception code to anything it wants, including | |
96 | * AE_OK, in which case the executing method will not be aborted. | |
97 | */ | |
98 | status = acpi_gbl_exception_handler(status, | |
99 | walk_state->method_node ? | |
100 | walk_state->method_node-> | |
101 | name.integer : 0, | |
102 | walk_state->opcode, | |
103 | walk_state->aml_offset, | |
104 | NULL); | |
105 | (void)acpi_ex_enter_interpreter(); | |
106 | } | |
107 | #ifdef ACPI_DISASSEMBLER | |
108 | if (ACPI_FAILURE(status)) { | |
52fc0b02 | 109 | |
defba1d8 BM |
110 | /* Display method locals/args if disassembler is present */ |
111 | ||
112 | acpi_dm_dump_method_info(status, walk_state, walk_state->op); | |
113 | } | |
114 | #endif | |
115 | ||
116 | return (status); | |
117 | } | |
118 | ||
967440e3 BM |
119 | /******************************************************************************* |
120 | * | |
121 | * FUNCTION: acpi_ds_create_method_mutex | |
122 | * | |
123 | * PARAMETERS: obj_desc - The method object | |
124 | * | |
125 | * RETURN: Status | |
126 | * | |
127 | * DESCRIPTION: Create a mutex object for a serialized control method | |
128 | * | |
129 | ******************************************************************************/ | |
130 | ||
131 | static acpi_status | |
132 | acpi_ds_create_method_mutex(union acpi_operand_object *method_desc) | |
133 | { | |
134 | union acpi_operand_object *mutex_desc; | |
135 | acpi_status status; | |
136 | ||
137 | ACPI_FUNCTION_NAME(ds_create_method_mutex); | |
138 | ||
139 | /* Create the new mutex object */ | |
140 | ||
141 | mutex_desc = acpi_ut_create_internal_object(ACPI_TYPE_MUTEX); | |
142 | if (!mutex_desc) { | |
143 | return_ACPI_STATUS(AE_NO_MEMORY); | |
144 | } | |
145 | ||
146 | /* Create the actual OS Mutex */ | |
147 | ||
148 | status = acpi_os_create_mutex(&mutex_desc->mutex.os_mutex); | |
149 | if (ACPI_FAILURE(status)) { | |
150 | return_ACPI_STATUS(status); | |
151 | } | |
152 | ||
153 | mutex_desc->mutex.sync_level = method_desc->method.sync_level; | |
154 | method_desc->method.mutex = mutex_desc; | |
155 | return_ACPI_STATUS(AE_OK); | |
156 | } | |
157 | ||
1da177e4 LT |
158 | /******************************************************************************* |
159 | * | |
160 | * FUNCTION: acpi_ds_begin_method_execution | |
161 | * | |
162 | * PARAMETERS: method_node - Node of the method | |
163 | * obj_desc - The method object | |
967440e3 BM |
164 | * walk_state - current state, NULL if not yet executing |
165 | * a method. | |
1da177e4 LT |
166 | * |
167 | * RETURN: Status | |
168 | * | |
169 | * DESCRIPTION: Prepare a method for execution. Parses the method if necessary, | |
170 | * increments the thread count, and waits at the method semaphore | |
171 | * for clearance to execute. | |
172 | * | |
173 | ******************************************************************************/ | |
defba1d8 | 174 | |
1da177e4 | 175 | acpi_status |
967440e3 BM |
176 | acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node, |
177 | union acpi_operand_object *obj_desc, | |
178 | struct acpi_walk_state *walk_state) | |
1da177e4 | 179 | { |
4be44fcd | 180 | acpi_status status = AE_OK; |
1da177e4 | 181 | |
b229cf92 | 182 | ACPI_FUNCTION_TRACE_PTR(ds_begin_method_execution, method_node); |
1da177e4 LT |
183 | |
184 | if (!method_node) { | |
4be44fcd | 185 | return_ACPI_STATUS(AE_NULL_ENTRY); |
1da177e4 LT |
186 | } |
187 | ||
aff8c277 RM |
188 | /* Prevent wraparound of thread count */ |
189 | ||
190 | if (obj_desc->method.thread_count == ACPI_UINT8_MAX) { | |
b8e4d893 BM |
191 | ACPI_ERROR((AE_INFO, |
192 | "Method reached maximum reentrancy limit (255)")); | |
aff8c277 RM |
193 | return_ACPI_STATUS(AE_AML_METHOD_LIMIT); |
194 | } | |
195 | ||
1da177e4 | 196 | /* |
967440e3 | 197 | * If this method is serialized, we need to acquire the method mutex. |
1da177e4 | 198 | */ |
967440e3 | 199 | if (obj_desc->method.method_flags & AML_METHOD_SERIALIZED) { |
1da177e4 | 200 | /* |
967440e3 BM |
201 | * Create a mutex for the method if it is defined to be Serialized |
202 | * and a mutex has not already been created. We defer the mutex creation | |
203 | * until a method is actually executed, to minimize the object count | |
1da177e4 | 204 | */ |
967440e3 BM |
205 | if (!obj_desc->method.mutex) { |
206 | status = acpi_ds_create_method_mutex(obj_desc); | |
207 | if (ACPI_FAILURE(status)) { | |
208 | return_ACPI_STATUS(status); | |
1da177e4 LT |
209 | } |
210 | } | |
211 | ||
212 | /* | |
967440e3 BM |
213 | * The current_sync_level (per-thread) must be less than or equal to |
214 | * the sync level of the method. This mechanism provides some | |
215 | * deadlock prevention | |
216 | * | |
217 | * Top-level method invocation has no walk state at this point | |
1da177e4 | 218 | */ |
967440e3 BM |
219 | if (walk_state && |
220 | (walk_state->thread->current_sync_level > | |
221 | obj_desc->method.mutex->mutex.sync_level)) { | |
222 | ACPI_ERROR((AE_INFO, | |
223 | "Cannot acquire Mutex for method [%4.4s], current SyncLevel is too large (%d)", | |
224 | acpi_ut_get_node_name(method_node), | |
225 | walk_state->thread->current_sync_level)); | |
226 | ||
227 | return_ACPI_STATUS(AE_AML_MUTEX_ORDER); | |
b229cf92 | 228 | } |
967440e3 BM |
229 | |
230 | /* | |
231 | * Obtain the method mutex if necessary. Do not acquire mutex for a | |
232 | * recursive call. | |
233 | */ | |
234 | if (!walk_state || | |
235 | !obj_desc->method.mutex->mutex.owner_thread || | |
236 | (walk_state->thread != | |
237 | obj_desc->method.mutex->mutex.owner_thread)) { | |
238 | /* | |
239 | * Acquire the method mutex. This releases the interpreter if we | |
240 | * block (and reacquires it before it returns) | |
241 | */ | |
242 | status = | |
243 | acpi_ex_system_wait_mutex(obj_desc->method.mutex-> | |
244 | mutex.os_mutex, | |
245 | ACPI_WAIT_FOREVER); | |
246 | if (ACPI_FAILURE(status)) { | |
247 | return_ACPI_STATUS(status); | |
248 | } | |
249 | ||
250 | /* Update the mutex and walk info and save the original sync_level */ | |
251 | ||
252 | if (walk_state) { | |
253 | obj_desc->method.mutex->mutex. | |
254 | original_sync_level = | |
255 | walk_state->thread->current_sync_level; | |
256 | ||
257 | obj_desc->method.mutex->mutex.owner_thread = | |
258 | walk_state->thread; | |
259 | walk_state->thread->current_sync_level = | |
260 | obj_desc->method.sync_level; | |
261 | } else { | |
262 | obj_desc->method.mutex->mutex. | |
263 | original_sync_level = | |
264 | obj_desc->method.mutex->mutex.sync_level; | |
265 | } | |
266 | } | |
267 | ||
268 | /* Always increase acquisition depth */ | |
269 | ||
270 | obj_desc->method.mutex->mutex.acquisition_depth++; | |
1da177e4 LT |
271 | } |
272 | ||
aff8c277 RM |
273 | /* |
274 | * Allocate an Owner ID for this method, only if this is the first thread | |
275 | * to begin concurrent execution. We only need one owner_id, even if the | |
276 | * method is invoked recursively. | |
277 | */ | |
278 | if (!obj_desc->method.owner_id) { | |
279 | status = acpi_ut_allocate_owner_id(&obj_desc->method.owner_id); | |
280 | if (ACPI_FAILURE(status)) { | |
b229cf92 | 281 | goto cleanup; |
aff8c277 RM |
282 | } |
283 | } | |
284 | ||
1da177e4 LT |
285 | /* |
286 | * Increment the method parse tree thread count since it has been | |
287 | * reentered one more time (even if it is the same thread) | |
288 | */ | |
289 | obj_desc->method.thread_count++; | |
4be44fcd | 290 | return_ACPI_STATUS(status); |
b229cf92 BM |
291 | |
292 | cleanup: | |
967440e3 | 293 | /* On error, must release the method mutex (if present) */ |
b229cf92 | 294 | |
967440e3 BM |
295 | if (obj_desc->method.mutex) { |
296 | acpi_os_release_mutex(obj_desc->method.mutex->mutex.os_mutex); | |
b229cf92 BM |
297 | } |
298 | return_ACPI_STATUS(status); | |
1da177e4 LT |
299 | } |
300 | ||
1da177e4 LT |
301 | /******************************************************************************* |
302 | * | |
303 | * FUNCTION: acpi_ds_call_control_method | |
304 | * | |
305 | * PARAMETERS: Thread - Info for this thread | |
306 | * this_walk_state - Current walk state | |
307 | * Op - Current Op to be walked | |
308 | * | |
309 | * RETURN: Status | |
310 | * | |
311 | * DESCRIPTION: Transfer execution to a called control method | |
312 | * | |
313 | ******************************************************************************/ | |
314 | ||
315 | acpi_status | |
4be44fcd LB |
316 | acpi_ds_call_control_method(struct acpi_thread_state *thread, |
317 | struct acpi_walk_state *this_walk_state, | |
318 | union acpi_parse_object *op) | |
1da177e4 | 319 | { |
4be44fcd LB |
320 | acpi_status status; |
321 | struct acpi_namespace_node *method_node; | |
322 | struct acpi_walk_state *next_walk_state = NULL; | |
323 | union acpi_operand_object *obj_desc; | |
4119532c | 324 | struct acpi_evaluate_info *info; |
4be44fcd | 325 | u32 i; |
1da177e4 | 326 | |
b229cf92 | 327 | ACPI_FUNCTION_TRACE_PTR(ds_call_control_method, this_walk_state); |
1da177e4 | 328 | |
4be44fcd LB |
329 | ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, |
330 | "Execute method %p, currentstate=%p\n", | |
331 | this_walk_state->prev_op, this_walk_state)); | |
1da177e4 LT |
332 | |
333 | /* | |
334 | * Get the namespace entry for the control method we are about to call | |
335 | */ | |
336 | method_node = this_walk_state->method_call_node; | |
337 | if (!method_node) { | |
4be44fcd | 338 | return_ACPI_STATUS(AE_NULL_ENTRY); |
1da177e4 LT |
339 | } |
340 | ||
4be44fcd | 341 | obj_desc = acpi_ns_get_attached_object(method_node); |
1da177e4 | 342 | if (!obj_desc) { |
4be44fcd | 343 | return_ACPI_STATUS(AE_NULL_OBJECT); |
1da177e4 LT |
344 | } |
345 | ||
967440e3 | 346 | /* Init for new method, possibly wait on method mutex */ |
1da177e4 | 347 | |
4be44fcd | 348 | status = acpi_ds_begin_method_execution(method_node, obj_desc, |
967440e3 | 349 | this_walk_state); |
4be44fcd | 350 | if (ACPI_FAILURE(status)) { |
b229cf92 | 351 | return_ACPI_STATUS(status); |
1da177e4 LT |
352 | } |
353 | ||
b229cf92 BM |
354 | /* |
355 | * 1) Parse the method. All "normal" methods are parsed for each execution. | |
356 | * Internal methods (_OSI, etc.) do not require parsing. | |
357 | */ | |
1da177e4 | 358 | if (!(obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY)) { |
52fc0b02 | 359 | |
b229cf92 | 360 | /* Create a new walk state for the parse */ |
1da177e4 | 361 | |
4be44fcd LB |
362 | next_walk_state = |
363 | acpi_ds_create_walk_state(obj_desc->method.owner_id, op, | |
364 | obj_desc, NULL); | |
1da177e4 | 365 | if (!next_walk_state) { |
b229cf92 BM |
366 | status = AE_NO_MEMORY; |
367 | goto cleanup; | |
1da177e4 LT |
368 | } |
369 | ||
b229cf92 | 370 | /* Create and init a parse tree root */ |
1da177e4 | 371 | |
4be44fcd | 372 | op = acpi_ps_create_scope_op(); |
1da177e4 LT |
373 | if (!op) { |
374 | status = AE_NO_MEMORY; | |
375 | goto cleanup; | |
376 | } | |
377 | ||
4be44fcd LB |
378 | status = acpi_ds_init_aml_walk(next_walk_state, op, method_node, |
379 | obj_desc->method.aml_start, | |
380 | obj_desc->method.aml_length, | |
381 | NULL, 1); | |
382 | if (ACPI_FAILURE(status)) { | |
b229cf92 | 383 | acpi_ps_delete_parse_tree(op); |
1da177e4 LT |
384 | goto cleanup; |
385 | } | |
386 | ||
b229cf92 | 387 | /* Begin AML parse (deletes next_walk_state) */ |
1da177e4 | 388 | |
4be44fcd LB |
389 | status = acpi_ps_parse_aml(next_walk_state); |
390 | acpi_ps_delete_parse_tree(op); | |
b229cf92 BM |
391 | if (ACPI_FAILURE(status)) { |
392 | goto cleanup; | |
393 | } | |
1da177e4 LT |
394 | } |
395 | ||
b229cf92 | 396 | /* 2) Begin method execution. Create a new walk state */ |
1da177e4 | 397 | |
4be44fcd LB |
398 | next_walk_state = acpi_ds_create_walk_state(obj_desc->method.owner_id, |
399 | NULL, obj_desc, thread); | |
1da177e4 LT |
400 | if (!next_walk_state) { |
401 | status = AE_NO_MEMORY; | |
402 | goto cleanup; | |
403 | } | |
b229cf92 | 404 | |
1da177e4 LT |
405 | /* |
406 | * The resolved arguments were put on the previous walk state's operand | |
aff8c277 RM |
407 | * stack. Operands on the previous walk state stack always |
408 | * start at index 0. Also, null terminate the list of arguments | |
1da177e4 | 409 | */ |
4be44fcd | 410 | this_walk_state->operands[this_walk_state->num_operands] = NULL; |
1da177e4 | 411 | |
4119532c BM |
412 | /* |
413 | * Allocate and initialize the evaluation information block | |
414 | * TBD: this is somewhat inefficient, should change interface to | |
415 | * ds_init_aml_walk. For now, keeps this struct off the CPU stack | |
416 | */ | |
417 | info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info)); | |
418 | if (!info) { | |
419 | return_ACPI_STATUS(AE_NO_MEMORY); | |
420 | } | |
421 | ||
422 | info->parameters = &this_walk_state->operands[0]; | |
423 | info->parameter_type = ACPI_PARAM_ARGS; | |
1da177e4 | 424 | |
4be44fcd LB |
425 | status = acpi_ds_init_aml_walk(next_walk_state, NULL, method_node, |
426 | obj_desc->method.aml_start, | |
4119532c BM |
427 | obj_desc->method.aml_length, info, 3); |
428 | ||
429 | ACPI_FREE(info); | |
4be44fcd | 430 | if (ACPI_FAILURE(status)) { |
1da177e4 LT |
431 | goto cleanup; |
432 | } | |
433 | ||
434 | /* | |
435 | * Delete the operands on the previous walkstate operand stack | |
436 | * (they were copied to new objects) | |
437 | */ | |
438 | for (i = 0; i < obj_desc->method.param_count; i++) { | |
4be44fcd LB |
439 | acpi_ut_remove_reference(this_walk_state->operands[i]); |
440 | this_walk_state->operands[i] = NULL; | |
1da177e4 LT |
441 | } |
442 | ||
443 | /* Clear the operand stack */ | |
444 | ||
445 | this_walk_state->num_operands = 0; | |
446 | ||
4be44fcd LB |
447 | ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, |
448 | "Starting nested execution, newstate=%p\n", | |
449 | next_walk_state)); | |
1da177e4 | 450 | |
b229cf92 BM |
451 | /* Invoke an internal method if necessary */ |
452 | ||
1da177e4 | 453 | if (obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY) { |
4be44fcd | 454 | status = obj_desc->method.implementation(next_walk_state); |
1da177e4 LT |
455 | } |
456 | ||
aff8c277 | 457 | return_ACPI_STATUS(status); |
a94f1881 LB |
458 | |
459 | cleanup: | |
a94f1881 | 460 | |
b229cf92 | 461 | /* On error, we must terminate the method properly */ |
aff8c277 | 462 | |
b229cf92 BM |
463 | acpi_ds_terminate_control_method(obj_desc, next_walk_state); |
464 | if (next_walk_state) { | |
465 | acpi_ds_delete_walk_state(next_walk_state); | |
466 | } | |
aff8c277 | 467 | |
4be44fcd | 468 | return_ACPI_STATUS(status); |
1da177e4 LT |
469 | } |
470 | ||
1da177e4 LT |
471 | /******************************************************************************* |
472 | * | |
473 | * FUNCTION: acpi_ds_restart_control_method | |
474 | * | |
475 | * PARAMETERS: walk_state - State for preempted method (caller) | |
476 | * return_desc - Return value from the called method | |
477 | * | |
478 | * RETURN: Status | |
479 | * | |
480 | * DESCRIPTION: Restart a method that was preempted by another (nested) method | |
481 | * invocation. Handle the return value (if any) from the callee. | |
482 | * | |
483 | ******************************************************************************/ | |
484 | ||
485 | acpi_status | |
4be44fcd LB |
486 | acpi_ds_restart_control_method(struct acpi_walk_state *walk_state, |
487 | union acpi_operand_object *return_desc) | |
1da177e4 | 488 | { |
4be44fcd | 489 | acpi_status status; |
958dd242 | 490 | int same_as_implicit_return; |
1da177e4 | 491 | |
b229cf92 | 492 | ACPI_FUNCTION_TRACE_PTR(ds_restart_control_method, walk_state); |
1da177e4 | 493 | |
4be44fcd | 494 | ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, |
b229cf92 | 495 | "****Restart [%4.4s] Op %p ReturnValueFromCallee %p\n", |
4be44fcd LB |
496 | (char *)&walk_state->method_node->name, |
497 | walk_state->method_call_op, return_desc)); | |
1da177e4 | 498 | |
4be44fcd | 499 | ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, |
b229cf92 | 500 | " ReturnFromThisMethodUsed?=%X ResStack %p Walk %p\n", |
4be44fcd LB |
501 | walk_state->return_used, |
502 | walk_state->results, walk_state)); | |
1da177e4 LT |
503 | |
504 | /* Did the called method return a value? */ | |
505 | ||
506 | if (return_desc) { | |
52fc0b02 | 507 | |
958dd242 BM |
508 | /* Is the implicit return object the same as the return desc? */ |
509 | ||
510 | same_as_implicit_return = | |
511 | (walk_state->implicit_return_obj == return_desc); | |
512 | ||
1da177e4 LT |
513 | /* Are we actually going to use the return value? */ |
514 | ||
515 | if (walk_state->return_used) { | |
52fc0b02 | 516 | |
1da177e4 LT |
517 | /* Save the return value from the previous method */ |
518 | ||
4be44fcd LB |
519 | status = acpi_ds_result_push(return_desc, walk_state); |
520 | if (ACPI_FAILURE(status)) { | |
521 | acpi_ut_remove_reference(return_desc); | |
522 | return_ACPI_STATUS(status); | |
1da177e4 LT |
523 | } |
524 | ||
525 | /* | |
526 | * Save as THIS method's return value in case it is returned | |
527 | * immediately to yet another method | |
528 | */ | |
529 | walk_state->return_desc = return_desc; | |
530 | } | |
531 | ||
532 | /* | |
958dd242 BM |
533 | * The following code is the optional support for the so-called |
534 | * "implicit return". Some AML code assumes that the last value of the | |
535 | * method is "implicitly" returned to the caller, in the absence of an | |
536 | * explicit return value. | |
537 | * | |
538 | * Just save the last result of the method as the return value. | |
539 | * | |
1da177e4 LT |
540 | * NOTE: this is optional because the ASL language does not actually |
541 | * support this behavior. | |
542 | */ | |
4be44fcd | 543 | else if (!acpi_ds_do_implicit_return |
958dd242 BM |
544 | (return_desc, walk_state, FALSE) |
545 | || same_as_implicit_return) { | |
1da177e4 LT |
546 | /* |
547 | * Delete the return value if it will not be used by the | |
958dd242 BM |
548 | * calling method or remove one reference if the explicit return |
549 | * is the same as the implicit return value. | |
1da177e4 | 550 | */ |
4be44fcd | 551 | acpi_ut_remove_reference(return_desc); |
1da177e4 LT |
552 | } |
553 | } | |
554 | ||
4be44fcd | 555 | return_ACPI_STATUS(AE_OK); |
1da177e4 LT |
556 | } |
557 | ||
1da177e4 LT |
558 | /******************************************************************************* |
559 | * | |
560 | * FUNCTION: acpi_ds_terminate_control_method | |
561 | * | |
b229cf92 BM |
562 | * PARAMETERS: method_desc - Method object |
563 | * walk_state - State associated with the method | |
1da177e4 | 564 | * |
aff8c277 | 565 | * RETURN: None |
1da177e4 LT |
566 | * |
567 | * DESCRIPTION: Terminate a control method. Delete everything that the method | |
568 | * created, delete all locals and arguments, and delete the parse | |
569 | * tree if requested. | |
570 | * | |
967440e3 BM |
571 | * MUTEX: Interpreter is locked |
572 | * | |
1da177e4 LT |
573 | ******************************************************************************/ |
574 | ||
b229cf92 BM |
575 | void |
576 | acpi_ds_terminate_control_method(union acpi_operand_object *method_desc, | |
577 | struct acpi_walk_state *walk_state) | |
1da177e4 | 578 | { |
4be44fcd LB |
579 | struct acpi_namespace_node *method_node; |
580 | acpi_status status; | |
1da177e4 | 581 | |
b229cf92 | 582 | ACPI_FUNCTION_TRACE_PTR(ds_terminate_control_method, walk_state); |
1da177e4 | 583 | |
b229cf92 | 584 | /* method_desc is required, walk_state is optional */ |
1da177e4 | 585 | |
b229cf92 | 586 | if (!method_desc) { |
aff8c277 | 587 | return_VOID; |
1da177e4 LT |
588 | } |
589 | ||
b229cf92 | 590 | if (walk_state) { |
1da177e4 | 591 | |
b229cf92 BM |
592 | /* Delete all arguments and locals */ |
593 | ||
594 | acpi_ds_method_data_delete_all(walk_state); | |
595 | } | |
1da177e4 LT |
596 | |
597 | /* | |
967440e3 BM |
598 | * If method is serialized, release the mutex and restore the |
599 | * current sync level for this thread | |
1da177e4 | 600 | */ |
967440e3 | 601 | if (method_desc->method.mutex) { |
1da177e4 | 602 | |
967440e3 | 603 | /* Acquisition Depth handles recursive calls */ |
1da177e4 | 604 | |
967440e3 BM |
605 | method_desc->method.mutex->mutex.acquisition_depth--; |
606 | if (!method_desc->method.mutex->mutex.acquisition_depth) { | |
607 | walk_state->thread->current_sync_level = | |
608 | method_desc->method.mutex->mutex. | |
609 | original_sync_level; | |
b229cf92 | 610 | |
967440e3 BM |
611 | acpi_os_release_mutex(method_desc->method.mutex->mutex. |
612 | os_mutex); | |
1da177e4 LT |
613 | } |
614 | } | |
615 | ||
b229cf92 BM |
616 | if (walk_state) { |
617 | /* | |
618 | * Delete any objects created by this method during execution. | |
619 | * The method Node is stored in the walk state | |
620 | */ | |
621 | method_node = walk_state->method_node; | |
28f55ebc | 622 | |
b229cf92 | 623 | /* Lock namespace for possible update */ |
28f55ebc | 624 | |
b229cf92 BM |
625 | status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE); |
626 | if (ACPI_FAILURE(status)) { | |
967440e3 | 627 | return_VOID; |
b229cf92 | 628 | } |
28f55ebc | 629 | |
b229cf92 BM |
630 | /* |
631 | * Delete any namespace entries created immediately underneath | |
632 | * the method | |
633 | */ | |
634 | if (method_node && method_node->child) { | |
635 | acpi_ns_delete_namespace_subtree(method_node); | |
636 | } | |
637 | ||
638 | /* | |
639 | * Delete any namespace entries created anywhere else within | |
640 | * the namespace by the execution of this method | |
641 | */ | |
642 | acpi_ns_delete_namespace_by_owner(method_desc->method.owner_id); | |
643 | status = acpi_ut_release_mutex(ACPI_MTX_NAMESPACE); | |
28f55ebc BM |
644 | } |
645 | ||
b229cf92 BM |
646 | /* Decrement the thread count on the method */ |
647 | ||
648 | if (method_desc->method.thread_count) { | |
649 | method_desc->method.thread_count--; | |
650 | } else { | |
651 | ACPI_ERROR((AE_INFO, "Invalid zero thread count in method")); | |
652 | } | |
28f55ebc BM |
653 | |
654 | /* Are there any other threads currently executing this method? */ | |
655 | ||
b229cf92 | 656 | if (method_desc->method.thread_count) { |
28f55ebc BM |
657 | /* |
658 | * Additional threads. Do not release the owner_id in this case, | |
659 | * we immediately reuse it for the next thread executing this method | |
660 | */ | |
4be44fcd | 661 | ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, |
28f55ebc | 662 | "*** Completed execution of one thread, %d threads remaining\n", |
b229cf92 | 663 | method_desc->method.thread_count)); |
28f55ebc BM |
664 | } else { |
665 | /* This is the only executing thread for this method */ | |
1da177e4 | 666 | |
1da177e4 LT |
667 | /* |
668 | * Support to dynamically change a method from not_serialized to | |
28f55ebc | 669 | * Serialized if it appears that the method is incorrectly written and |
967440e3 BM |
670 | * does not support multiple thread execution. The best example of this |
671 | * is if such a method creates namespace objects and blocks. A second | |
1da177e4 LT |
672 | * thread will fail with an AE_ALREADY_EXISTS exception |
673 | * | |
674 | * This code is here because we must wait until the last thread exits | |
675 | * before creating the synchronization semaphore. | |
676 | */ | |
967440e3 BM |
677 | if ((method_desc->method.method_flags & AML_METHOD_SERIALIZED) |
678 | && (!method_desc->method.mutex)) { | |
679 | status = acpi_ds_create_method_mutex(method_desc); | |
1da177e4 LT |
680 | } |
681 | ||
28f55ebc | 682 | /* No more threads, we can free the owner_id */ |
1da177e4 | 683 | |
b229cf92 | 684 | acpi_ut_release_owner_id(&method_desc->method.owner_id); |
1da177e4 | 685 | } |
a94f1881 | 686 | |
aff8c277 | 687 | return_VOID; |
1da177e4 | 688 | } |