1/****************************************************************************** 2 * 3 * Module Name: dsmethod - Parser/Interpreter interface - control method parsing 4 * 5 *****************************************************************************/ 6 7/* 8 * Copyright (C) 2000 - 2010, 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#include <acpi/acpi.h> 45#include "accommon.h" 46#include "amlcode.h" 47#include "acdispat.h" 48#include "acinterp.h" 49#include "acnamesp.h" 50#ifdef ACPI_DISASSEMBLER 51#include <acpi/acdisasm.h> 52#endif 53 54#define _COMPONENT ACPI_DISPATCHER 55ACPI_MODULE_NAME("dsmethod") 56 57/* Local prototypes */ 58static acpi_status 59acpi_ds_create_method_mutex(union acpi_operand_object *method_desc); 60 61/******************************************************************************* 62 * 63 * FUNCTION: acpi_ds_method_error 64 * 65 * PARAMETERS: Status - Execution status 66 * walk_state - Current state 67 * 68 * RETURN: Status 69 * 70 * DESCRIPTION: Called on method error. Invoke the global exception handler if 71 * present, dump the method data if the disassembler is configured 72 * 73 * Note: Allows the exception handler to change the status code 74 * 75 ******************************************************************************/ 76 77acpi_status 78acpi_ds_method_error(acpi_status status, struct acpi_walk_state *walk_state) 79{ 80 ACPI_FUNCTION_ENTRY(); 81 82 /* Ignore AE_OK and control exception codes */ 83 84 if (ACPI_SUCCESS(status) || (status & AE_CODE_CONTROL)) { 85 return (status); 86 } 87 88 /* Invoke the global exception handler */ 89 90 if (acpi_gbl_exception_handler) { 91 92 /* Exit the interpreter, allow handler to execute methods */ 93 94 acpi_ex_exit_interpreter(); 95 96 /* 97 * Handler can map the exception code to anything it wants, including 98 * AE_OK, in which case the executing method will not be aborted. 99 */ 100 status = acpi_gbl_exception_handler(status, 101 walk_state->method_node ? 102 walk_state->method_node-> 103 name.integer : 0, 104 walk_state->opcode, 105 walk_state->aml_offset, 106 NULL); 107 acpi_ex_enter_interpreter(); 108 } 109 110 acpi_ds_clear_implicit_return(walk_state); 111 112#ifdef ACPI_DISASSEMBLER 113 if (ACPI_FAILURE(status)) { 114 115 /* Display method locals/args if disassembler is present */ 116 117 acpi_dm_dump_method_info(status, walk_state, walk_state->op); 118 } 119#endif 120 121 return (status); 122} 123 124/******************************************************************************* 125 * 126 * FUNCTION: acpi_ds_create_method_mutex 127 * 128 * PARAMETERS: obj_desc - The method object 129 * 130 * RETURN: Status 131 * 132 * DESCRIPTION: Create a mutex object for a serialized control method 133 * 134 ******************************************************************************/ 135 136static acpi_status 137acpi_ds_create_method_mutex(union acpi_operand_object *method_desc) 138{ 139 union acpi_operand_object *mutex_desc; 140 acpi_status status; 141 142 ACPI_FUNCTION_TRACE(ds_create_method_mutex); 143 144 /* Create the new mutex object */ 145 146 mutex_desc = acpi_ut_create_internal_object(ACPI_TYPE_MUTEX); 147 if (!mutex_desc) { 148 return_ACPI_STATUS(AE_NO_MEMORY); 149 } 150 151 /* Create the actual OS Mutex */ 152 153 status = acpi_os_create_mutex(&mutex_desc->mutex.os_mutex); 154 if (ACPI_FAILURE(status)) { 155 return_ACPI_STATUS(status); 156 } 157 158 mutex_desc->mutex.sync_level = method_desc->method.sync_level; 159 method_desc->method.mutex = mutex_desc; 160 return_ACPI_STATUS(AE_OK); 161} 162 163/******************************************************************************* 164 * 165 * FUNCTION: acpi_ds_begin_method_execution 166 * 167 * PARAMETERS: method_node - Node of the method 168 * obj_desc - The method object 169 * walk_state - current state, NULL if not yet executing 170 * a method. 171 * 172 * RETURN: Status 173 * 174 * DESCRIPTION: Prepare a method for execution. Parses the method if necessary, 175 * increments the thread count, and waits at the method semaphore 176 * for clearance to execute. 177 * 178 ******************************************************************************/ 179 180acpi_status 181acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node, 182 union acpi_operand_object *obj_desc, 183 struct acpi_walk_state *walk_state) 184{ 185 acpi_status status = AE_OK; 186 187 ACPI_FUNCTION_TRACE_PTR(ds_begin_method_execution, method_node); 188 189 if (!method_node) { 190 return_ACPI_STATUS(AE_NULL_ENTRY); 191 } 192 193 /* Prevent wraparound of thread count */ 194 195 if (obj_desc->method.thread_count == ACPI_UINT8_MAX) { 196 ACPI_ERROR((AE_INFO, 197 "Method reached maximum reentrancy limit (255)")); 198 return_ACPI_STATUS(AE_AML_METHOD_LIMIT); 199 } 200 201 /* 202 * If this method is serialized, we need to acquire the method mutex. 203 */ 204 if (obj_desc->method.method_flags & AML_METHOD_SERIALIZED) { 205 /* 206 * Create a mutex for the method if it is defined to be Serialized 207 * and a mutex has not already been created. We defer the mutex creation 208 * until a method is actually executed, to minimize the object count 209 */ 210 if (!obj_desc->method.mutex) { 211 status = acpi_ds_create_method_mutex(obj_desc); 212 if (ACPI_FAILURE(status)) { 213 return_ACPI_STATUS(status); 214 } 215 } 216 217 /* 218 * The current_sync_level (per-thread) must be less than or equal to 219 * the sync level of the method. This mechanism provides some 220 * deadlock prevention 221 * 222 * Top-level method invocation has no walk state at this point 223 */ 224 if (walk_state && 225 (walk_state->thread->current_sync_level > 226 obj_desc->method.mutex->mutex.sync_level)) { 227 ACPI_ERROR((AE_INFO, 228 "Cannot acquire Mutex for method [%4.4s], current SyncLevel is too large (%u)", 229 acpi_ut_get_node_name(method_node), 230 walk_state->thread->current_sync_level)); 231 232 return_ACPI_STATUS(AE_AML_MUTEX_ORDER); 233 } 234 235 /* 236 * Obtain the method mutex if necessary. Do not acquire mutex for a 237 * recursive call. 238 */ 239 if (!walk_state || 240 !obj_desc->method.mutex->mutex.thread_id || 241 (walk_state->thread->thread_id != 242 obj_desc->method.mutex->mutex.thread_id)) { 243 /* 244 * Acquire the method mutex. This releases the interpreter if we 245 * block (and reacquires it before it returns) 246 */ 247 status = 248 acpi_ex_system_wait_mutex(obj_desc->method.mutex-> 249 mutex.os_mutex, 250 ACPI_WAIT_FOREVER); 251 if (ACPI_FAILURE(status)) { 252 return_ACPI_STATUS(status); 253 } 254 255 /* Update the mutex and walk info and save the original sync_level */ 256 257 if (walk_state) { 258 obj_desc->method.mutex->mutex. 259 original_sync_level = 260 walk_state->thread->current_sync_level; 261 262 obj_desc->method.mutex->mutex.thread_id = 263 walk_state->thread->thread_id; 264 walk_state->thread->current_sync_level = 265 obj_desc->method.sync_level; 266 } else { 267 obj_desc->method.mutex->mutex. 268 original_sync_level = 269 obj_desc->method.mutex->mutex.sync_level; 270 } 271 } 272 273 /* Always increase acquisition depth */ 274 275 obj_desc->method.mutex->mutex.acquisition_depth++; 276 } 277 278 /* 279 * Allocate an Owner ID for this method, only if this is the first thread 280 * to begin concurrent execution. We only need one owner_id, even if the 281 * method is invoked recursively. 282 */ 283 if (!obj_desc->method.owner_id) { 284 status = acpi_ut_allocate_owner_id(&obj_desc->method.owner_id); 285 if (ACPI_FAILURE(status)) { 286 goto cleanup; 287 } 288 } 289 290 /* 291 * Increment the method parse tree thread count since it has been 292 * reentered one more time (even if it is the same thread) 293 */ 294 obj_desc->method.thread_count++; 295 return_ACPI_STATUS(status); 296 297 cleanup: 298 /* On error, must release the method mutex (if present) */ 299 300 if (obj_desc->method.mutex) { 301 acpi_os_release_mutex(obj_desc->method.mutex->mutex.os_mutex); 302 } 303 return_ACPI_STATUS(status); 304} 305 306/******************************************************************************* 307 * 308 * FUNCTION: acpi_ds_call_control_method 309 * 310 * PARAMETERS: Thread - Info for this thread 311 * this_walk_state - Current walk state 312 * Op - Current Op to be walked 313 * 314 * RETURN: Status 315 * 316 * DESCRIPTION: Transfer execution to a called control method 317 * 318 ******************************************************************************/ 319 320acpi_status 321acpi_ds_call_control_method(struct acpi_thread_state *thread, 322 struct acpi_walk_state *this_walk_state, 323 union acpi_parse_object *op) 324{ 325 acpi_status status; 326 struct acpi_namespace_node *method_node; 327 struct acpi_walk_state *next_walk_state = NULL; 328 union acpi_operand_object *obj_desc; 329 struct acpi_evaluate_info *info; 330 u32 i; 331 332 ACPI_FUNCTION_TRACE_PTR(ds_call_control_method, this_walk_state); 333 334 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, 335 "Calling method %p, currentstate=%p\n", 336 this_walk_state->prev_op, this_walk_state)); 337 338 /* 339 * Get the namespace entry for the control method we are about to call 340 */ 341 method_node = this_walk_state->method_call_node; 342 if (!method_node) { 343 return_ACPI_STATUS(AE_NULL_ENTRY); 344 } 345 346 obj_desc = acpi_ns_get_attached_object(method_node); 347 if (!obj_desc) { 348 return_ACPI_STATUS(AE_NULL_OBJECT); 349 } 350 351 /* Init for new method, possibly wait on method mutex */ 352 353 status = acpi_ds_begin_method_execution(method_node, obj_desc, 354 this_walk_state); 355 if (ACPI_FAILURE(status)) { 356 return_ACPI_STATUS(status); 357 } 358 359 /* Begin method parse/execution. Create a new walk state */ 360 361 next_walk_state = acpi_ds_create_walk_state(obj_desc->method.owner_id, 362 NULL, obj_desc, thread); 363 if (!next_walk_state) { 364 status = AE_NO_MEMORY; 365 goto cleanup; 366 } 367 368 /* 369 * The resolved arguments were put on the previous walk state's operand 370 * stack. Operands on the previous walk state stack always 371 * start at index 0. Also, null terminate the list of arguments 372 */ 373 this_walk_state->operands[this_walk_state->num_operands] = NULL; 374 375 /* 376 * Allocate and initialize the evaluation information block 377 * TBD: this is somewhat inefficient, should change interface to 378 * ds_init_aml_walk. For now, keeps this struct off the CPU stack 379 */ 380 info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info)); 381 if (!info) { 382 return_ACPI_STATUS(AE_NO_MEMORY); 383 } 384 385 info->parameters = &this_walk_state->operands[0]; 386 387 status = acpi_ds_init_aml_walk(next_walk_state, NULL, method_node, 388 obj_desc->method.aml_start, 389 obj_desc->method.aml_length, info, 390 ACPI_IMODE_EXECUTE); 391 392 ACPI_FREE(info); 393 if (ACPI_FAILURE(status)) { 394 goto cleanup; 395 } 396 397 /* 398 * Delete the operands on the previous walkstate operand stack 399 * (they were copied to new objects) 400 */ 401 for (i = 0; i < obj_desc->method.param_count; i++) { 402 acpi_ut_remove_reference(this_walk_state->operands[i]); 403 this_walk_state->operands[i] = NULL; 404 } 405 406 /* Clear the operand stack */ 407 408 this_walk_state->num_operands = 0; 409 410 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, 411 "**** Begin nested execution of [%4.4s] **** WalkState=%p\n", 412 method_node->name.ascii, next_walk_state)); 413 414 /* Invoke an internal method if necessary */ 415 416 if (obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY) { 417 status = obj_desc->method.extra.implementation(next_walk_state); 418 if (status == AE_OK) { 419 status = AE_CTRL_TERMINATE; 420 } 421 } 422 423 return_ACPI_STATUS(status); 424 425 cleanup: 426 427 /* On error, we must terminate the method properly */ 428 429 acpi_ds_terminate_control_method(obj_desc, next_walk_state); 430 if (next_walk_state) { 431 acpi_ds_delete_walk_state(next_walk_state); 432 } 433 434 return_ACPI_STATUS(status); 435} 436 437/******************************************************************************* 438 * 439 * FUNCTION: acpi_ds_restart_control_method 440 * 441 * PARAMETERS: walk_state - State for preempted method (caller) 442 * return_desc - Return value from the called method 443 * 444 * RETURN: Status 445 * 446 * DESCRIPTION: Restart a method that was preempted by another (nested) method 447 * invocation. Handle the return value (if any) from the callee. 448 * 449 ******************************************************************************/ 450 451acpi_status 452acpi_ds_restart_control_method(struct acpi_walk_state *walk_state, 453 union acpi_operand_object *return_desc) 454{ 455 acpi_status status; 456 int same_as_implicit_return; 457 458 ACPI_FUNCTION_TRACE_PTR(ds_restart_control_method, walk_state); 459 460 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, 461 "****Restart [%4.4s] Op %p ReturnValueFromCallee %p\n", 462 acpi_ut_get_node_name(walk_state->method_node), 463 walk_state->method_call_op, return_desc)); 464 465 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, 466 " ReturnFromThisMethodUsed?=%X ResStack %p Walk %p\n", 467 walk_state->return_used, 468 walk_state->results, walk_state)); 469 470 /* Did the called method return a value? */ 471 472 if (return_desc) { 473 474 /* Is the implicit return object the same as the return desc? */ 475 476 same_as_implicit_return = 477 (walk_state->implicit_return_obj == return_desc); 478 479 /* Are we actually going to use the return value? */ 480 481 if (walk_state->return_used) { 482 483 /* Save the return value from the previous method */ 484 485 status = acpi_ds_result_push(return_desc, walk_state); 486 if (ACPI_FAILURE(status)) { 487 acpi_ut_remove_reference(return_desc); 488 return_ACPI_STATUS(status); 489 } 490 491 /* 492 * Save as THIS method's return value in case it is returned 493 * immediately to yet another method 494 */ 495 walk_state->return_desc = return_desc; 496 } 497 498 /* 499 * The following code is the optional support for the so-called 500 * "implicit return". Some AML code assumes that the last value of the 501 * method is "implicitly" returned to the caller, in the absence of an 502 * explicit return value. 503 * 504 * Just save the last result of the method as the return value. 505 * 506 * NOTE: this is optional because the ASL language does not actually 507 * support this behavior. 508 */ 509 else if (!acpi_ds_do_implicit_return 510 (return_desc, walk_state, FALSE) 511 || same_as_implicit_return) { 512 /* 513 * Delete the return value if it will not be used by the 514 * calling method or remove one reference if the explicit return 515 * is the same as the implicit return value. 516 */ 517 acpi_ut_remove_reference(return_desc); 518 } 519 } 520 521 return_ACPI_STATUS(AE_OK); 522} 523 524/******************************************************************************* 525 * 526 * FUNCTION: acpi_ds_terminate_control_method 527 * 528 * PARAMETERS: method_desc - Method object 529 * walk_state - State associated with the method 530 * 531 * RETURN: None 532 * 533 * DESCRIPTION: Terminate a control method. Delete everything that the method 534 * created, delete all locals and arguments, and delete the parse 535 * tree if requested. 536 * 537 * MUTEX: Interpreter is locked 538 * 539 ******************************************************************************/ 540 541void 542acpi_ds_terminate_control_method(union acpi_operand_object *method_desc, 543 struct acpi_walk_state *walk_state) 544{ 545 546 ACPI_FUNCTION_TRACE_PTR(ds_terminate_control_method, walk_state); 547 548 /* method_desc is required, walk_state is optional */ 549 550 if (!method_desc) { 551 return_VOID; 552 } 553 554 if (walk_state) { 555 556 /* Delete all arguments and locals */ 557 558 acpi_ds_method_data_delete_all(walk_state); 559 560 /* 561 * If method is serialized, release the mutex and restore the 562 * current sync level for this thread 563 */ 564 if (method_desc->method.mutex) { 565 566 /* Acquisition Depth handles recursive calls */ 567 568 method_desc->method.mutex->mutex.acquisition_depth--; 569 if (!method_desc->method.mutex->mutex.acquisition_depth) { 570 walk_state->thread->current_sync_level = 571 method_desc->method.mutex->mutex. 572 original_sync_level; 573 574 acpi_os_release_mutex(method_desc->method. 575 mutex->mutex.os_mutex); 576 method_desc->method.mutex->mutex.thread_id = NULL; 577 } 578 } 579 580 /* 581 * Delete any namespace objects created anywhere within the 582 * namespace by the execution of this method. Unless this method 583 * is a module-level executable code method, in which case we 584 * want make the objects permanent. 585 */ 586 if (!(method_desc->method.flags & AOPOBJ_MODULE_LEVEL)) { 587 588 /* Delete any direct children of (created by) this method */ 589 590 acpi_ns_delete_namespace_subtree(walk_state-> 591 method_node); 592 593 /* 594 * Delete any objects that were created by this method 595 * elsewhere in the namespace (if any were created). 596 */ 597 if (method_desc->method. 598 flags & AOPOBJ_MODIFIED_NAMESPACE) { 599 acpi_ns_delete_namespace_by_owner(method_desc-> 600 method. 601 owner_id); 602 } 603 } 604 } 605 606 /* Decrement the thread count on the method */ 607 608 if (method_desc->method.thread_count) { 609 method_desc->method.thread_count--; 610 } else { 611 ACPI_ERROR((AE_INFO, "Invalid zero thread count in method")); 612 } 613 614 /* Are there any other threads currently executing this method? */ 615 616 if (method_desc->method.thread_count) { 617 /* 618 * Additional threads. Do not release the owner_id in this case, 619 * we immediately reuse it for the next thread executing this method 620 */ 621 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, 622 "*** Completed execution of one thread, %u threads remaining\n", 623 method_desc->method.thread_count)); 624 } else { 625 /* This is the only executing thread for this method */ 626 627 /* 628 * Support to dynamically change a method from not_serialized to 629 * Serialized if it appears that the method is incorrectly written and 630 * does not support multiple thread execution. The best example of this 631 * is if such a method creates namespace objects and blocks. A second 632 * thread will fail with an AE_ALREADY_EXISTS exception 633 * 634 * This code is here because we must wait until the last thread exits 635 * before creating the synchronization semaphore. 636 */ 637 if ((method_desc->method.method_flags & AML_METHOD_SERIALIZED) 638 && (!method_desc->method.mutex)) { 639 (void)acpi_ds_create_method_mutex(method_desc); 640 } 641 642 /* No more threads, we can free the owner_id */ 643 644 if (!(method_desc->method.flags & AOPOBJ_MODULE_LEVEL)) { 645 acpi_ut_release_owner_id(&method_desc->method.owner_id); 646 } 647 } 648 649 return_VOID; 650} 651