1 2/****************************************************************************** 3 * 4 * Module Name: exmutex - ASL Mutex Acquire/Release functions 5 * 6 *****************************************************************************/ 7 8/* 9 * Copyright (C) 2000 - 2010, Intel Corp. 10 * All rights reserved. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions, and the following disclaimer, 17 * without modification. 18 * 2. Redistributions in binary form must reproduce at minimum a disclaimer 19 * substantially similar to the "NO WARRANTY" disclaimer below 20 * ("Disclaimer") and any redistribution must be conditioned upon 21 * including a substantially similar Disclaimer requirement for further 22 * binary redistribution. 23 * 3. Neither the names of the above-listed copyright holders nor the names 24 * of any contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * Alternatively, this software may be distributed under the terms of the 28 * GNU General Public License ("GPL") version 2 as published by the Free 29 * Software Foundation. 30 * 31 * NO WARRANTY 32 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 33 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 34 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR 35 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 36 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 37 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 38 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 40 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 41 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 42 * POSSIBILITY OF SUCH DAMAGES. 43 */ 44 45#include <acpi/acpi.h> 46#include "accommon.h" 47#include "acinterp.h" 48#include "acevents.h" 49 50#define _COMPONENT ACPI_EXECUTER 51ACPI_MODULE_NAME("exmutex") 52 53/* Local prototypes */ 54static void 55acpi_ex_link_mutex(union acpi_operand_object *obj_desc, 56 struct acpi_thread_state *thread); 57 58/******************************************************************************* 59 * 60 * FUNCTION: acpi_ex_unlink_mutex 61 * 62 * PARAMETERS: obj_desc - The mutex to be unlinked 63 * 64 * RETURN: None 65 * 66 * DESCRIPTION: Remove a mutex from the "AcquiredMutex" list 67 * 68 ******************************************************************************/ 69 70void acpi_ex_unlink_mutex(union acpi_operand_object *obj_desc) 71{ 72 struct acpi_thread_state *thread = obj_desc->mutex.owner_thread; 73 74 if (!thread) { 75 return; 76 } 77 78 /* Doubly linked list */ 79 80 if (obj_desc->mutex.next) { 81 (obj_desc->mutex.next)->mutex.prev = obj_desc->mutex.prev; 82 } 83 84 if (obj_desc->mutex.prev) { 85 (obj_desc->mutex.prev)->mutex.next = obj_desc->mutex.next; 86 87 /* 88 * Migrate the previous sync level associated with this mutex to 89 * the previous mutex on the list so that it may be preserved. 90 * This handles the case where several mutexes have been acquired 91 * at the same level, but are not released in opposite order. 92 */ 93 (obj_desc->mutex.prev)->mutex.original_sync_level = 94 obj_desc->mutex.original_sync_level; 95 } else { 96 thread->acquired_mutex_list = obj_desc->mutex.next; 97 } 98} 99 100/******************************************************************************* 101 * 102 * FUNCTION: acpi_ex_link_mutex 103 * 104 * PARAMETERS: obj_desc - The mutex to be linked 105 * Thread - Current executing thread object 106 * 107 * RETURN: None 108 * 109 * DESCRIPTION: Add a mutex to the "AcquiredMutex" list for this walk 110 * 111 ******************************************************************************/ 112 113static void 114acpi_ex_link_mutex(union acpi_operand_object *obj_desc, 115 struct acpi_thread_state *thread) 116{ 117 union acpi_operand_object *list_head; 118 119 list_head = thread->acquired_mutex_list; 120 121 /* This object will be the first object in the list */ 122 123 obj_desc->mutex.prev = NULL; 124 obj_desc->mutex.next = list_head; 125 126 /* Update old first object to point back to this object */ 127 128 if (list_head) { 129 list_head->mutex.prev = obj_desc; 130 } 131 132 /* Update list head */ 133 134 thread->acquired_mutex_list = obj_desc; 135} 136 137/******************************************************************************* 138 * 139 * FUNCTION: acpi_ex_acquire_mutex_object 140 * 141 * PARAMETERS: Timeout - Timeout in milliseconds 142 * obj_desc - Mutex object 143 * thread_id - Current thread state 144 * 145 * RETURN: Status 146 * 147 * DESCRIPTION: Acquire an AML mutex, low-level interface. Provides a common 148 * path that supports multiple acquires by the same thread. 149 * 150 * MUTEX: Interpreter must be locked 151 * 152 * NOTE: This interface is called from three places: 153 * 1) From acpi_ex_acquire_mutex, via an AML Acquire() operator 154 * 2) From acpi_ex_acquire_global_lock when an AML Field access requires the 155 * global lock 156 * 3) From the external interface, acpi_acquire_global_lock 157 * 158 ******************************************************************************/ 159 160acpi_status 161acpi_ex_acquire_mutex_object(u16 timeout, 162 union acpi_operand_object *obj_desc, 163 acpi_thread_id thread_id) 164{ 165 acpi_status status; 166 167 ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex_object, obj_desc); 168 169 if (!obj_desc) { 170 return_ACPI_STATUS(AE_BAD_PARAMETER); 171 } 172 173 /* Support for multiple acquires by the owning thread */ 174 175 if (obj_desc->mutex.thread_id == thread_id) { 176 /* 177 * The mutex is already owned by this thread, just increment the 178 * acquisition depth 179 */ 180 obj_desc->mutex.acquisition_depth++; 181 return_ACPI_STATUS(AE_OK); 182 } 183 184 /* Acquire the mutex, wait if necessary. Special case for Global Lock */ 185 186 if (obj_desc == acpi_gbl_global_lock_mutex) { 187 status = acpi_ev_acquire_global_lock(timeout); 188 } else { 189 status = acpi_ex_system_wait_mutex(obj_desc->mutex.os_mutex, 190 timeout); 191 } 192 193 if (ACPI_FAILURE(status)) { 194 195 /* Includes failure from a timeout on time_desc */ 196 197 return_ACPI_STATUS(status); 198 } 199 200 /* Acquired the mutex: update mutex object */ 201 202 obj_desc->mutex.thread_id = thread_id; 203 obj_desc->mutex.acquisition_depth = 1; 204 obj_desc->mutex.original_sync_level = 0; 205 obj_desc->mutex.owner_thread = NULL; /* Used only for AML Acquire() */ 206 207 return_ACPI_STATUS(AE_OK); 208} 209 210/******************************************************************************* 211 * 212 * FUNCTION: acpi_ex_acquire_mutex 213 * 214 * PARAMETERS: time_desc - Timeout integer 215 * obj_desc - Mutex object 216 * walk_state - Current method execution state 217 * 218 * RETURN: Status 219 * 220 * DESCRIPTION: Acquire an AML mutex 221 * 222 ******************************************************************************/ 223 224acpi_status 225acpi_ex_acquire_mutex(union acpi_operand_object *time_desc, 226 union acpi_operand_object *obj_desc, 227 struct acpi_walk_state *walk_state) 228{ 229 acpi_status status; 230 231 ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex, obj_desc); 232 233 if (!obj_desc) { 234 return_ACPI_STATUS(AE_BAD_PARAMETER); 235 } 236 237 /* Must have a valid thread state struct */ 238 239 if (!walk_state->thread) { 240 ACPI_ERROR((AE_INFO, 241 "Cannot acquire Mutex [%4.4s], null thread info", 242 acpi_ut_get_node_name(obj_desc->mutex.node))); 243 return_ACPI_STATUS(AE_AML_INTERNAL); 244 } 245 246 /* 247 * Current sync level must be less than or equal to the sync level of the 248 * mutex. This mechanism provides some deadlock prevention 249 */ 250 if (walk_state->thread->current_sync_level > obj_desc->mutex.sync_level) { 251 ACPI_ERROR((AE_INFO, 252 "Cannot acquire Mutex [%4.4s], current SyncLevel is too large (%u)", 253 acpi_ut_get_node_name(obj_desc->mutex.node), 254 walk_state->thread->current_sync_level)); 255 return_ACPI_STATUS(AE_AML_MUTEX_ORDER); 256 } 257 258 status = acpi_ex_acquire_mutex_object((u16) time_desc->integer.value, 259 obj_desc, 260 walk_state->thread->thread_id); 261 if (ACPI_SUCCESS(status) && obj_desc->mutex.acquisition_depth == 1) { 262 263 /* Save Thread object, original/current sync levels */ 264 265 obj_desc->mutex.owner_thread = walk_state->thread; 266 obj_desc->mutex.original_sync_level = 267 walk_state->thread->current_sync_level; 268 walk_state->thread->current_sync_level = 269 obj_desc->mutex.sync_level; 270 271 /* Link the mutex to the current thread for force-unlock at method exit */ 272 273 acpi_ex_link_mutex(obj_desc, walk_state->thread); 274 } 275 276 return_ACPI_STATUS(status); 277} 278 279/******************************************************************************* 280 * 281 * FUNCTION: acpi_ex_release_mutex_object 282 * 283 * PARAMETERS: obj_desc - The object descriptor for this op 284 * 285 * RETURN: Status 286 * 287 * DESCRIPTION: Release a previously acquired Mutex, low level interface. 288 * Provides a common path that supports multiple releases (after 289 * previous multiple acquires) by the same thread. 290 * 291 * MUTEX: Interpreter must be locked 292 * 293 * NOTE: This interface is called from three places: 294 * 1) From acpi_ex_release_mutex, via an AML Acquire() operator 295 * 2) From acpi_ex_release_global_lock when an AML Field access requires the 296 * global lock 297 * 3) From the external interface, acpi_release_global_lock 298 * 299 ******************************************************************************/ 300 301acpi_status acpi_ex_release_mutex_object(union acpi_operand_object *obj_desc) 302{ 303 acpi_status status = AE_OK; 304 305 ACPI_FUNCTION_TRACE(ex_release_mutex_object); 306 307 if (obj_desc->mutex.acquisition_depth == 0) { 308 return (AE_NOT_ACQUIRED); 309 } 310 311 /* Match multiple Acquires with multiple Releases */ 312 313 obj_desc->mutex.acquisition_depth--; 314 if (obj_desc->mutex.acquisition_depth != 0) { 315 316 /* Just decrement the depth and return */ 317 318 return_ACPI_STATUS(AE_OK); 319 } 320 321 if (obj_desc->mutex.owner_thread) { 322 323 /* Unlink the mutex from the owner's list */ 324 325 acpi_ex_unlink_mutex(obj_desc); 326 obj_desc->mutex.owner_thread = NULL; 327 } 328 329 /* Release the mutex, special case for Global Lock */ 330 331 if (obj_desc == acpi_gbl_global_lock_mutex) { 332 status = acpi_ev_release_global_lock(); 333 } else { 334 acpi_os_release_mutex(obj_desc->mutex.os_mutex); 335 } 336 337 /* Clear mutex info */ 338 339 obj_desc->mutex.thread_id = NULL; 340 return_ACPI_STATUS(status); 341} 342 343/******************************************************************************* 344 * 345 * FUNCTION: acpi_ex_release_mutex 346 * 347 * PARAMETERS: obj_desc - The object descriptor for this op 348 * walk_state - Current method execution state 349 * 350 * RETURN: Status 351 * 352 * DESCRIPTION: Release a previously acquired Mutex. 353 * 354 ******************************************************************************/ 355 356acpi_status 357acpi_ex_release_mutex(union acpi_operand_object *obj_desc, 358 struct acpi_walk_state *walk_state) 359{ 360 acpi_status status = AE_OK; 361 u8 previous_sync_level; 362 struct acpi_thread_state *owner_thread; 363 364 ACPI_FUNCTION_TRACE(ex_release_mutex); 365 366 if (!obj_desc) { 367 return_ACPI_STATUS(AE_BAD_PARAMETER); 368 } 369 370 owner_thread = obj_desc->mutex.owner_thread; 371 372 /* The mutex must have been previously acquired in order to release it */ 373 374 if (!owner_thread) { 375 ACPI_ERROR((AE_INFO, 376 "Cannot release Mutex [%4.4s], not acquired", 377 acpi_ut_get_node_name(obj_desc->mutex.node))); 378 return_ACPI_STATUS(AE_AML_MUTEX_NOT_ACQUIRED); 379 } 380 381 /* Must have a valid thread. */ 382 if (!walk_state->thread) { 383 ACPI_ERROR((AE_INFO, 384 "Cannot release Mutex [%4.4s], null thread info", 385 acpi_ut_get_node_name(obj_desc->mutex.node))); 386 return_ACPI_STATUS(AE_AML_INTERNAL); 387 } 388 389 /* 390 * The Mutex is owned, but this thread must be the owner. 391 * Special case for Global Lock, any thread can release 392 */ 393 if ((owner_thread->thread_id != walk_state->thread->thread_id) && 394 (obj_desc != acpi_gbl_global_lock_mutex)) { 395 ACPI_ERROR((AE_INFO, 396 "Thread %p cannot release Mutex [%4.4s] acquired by thread %p", 397 ACPI_CAST_PTR(void, walk_state->thread->thread_id), 398 acpi_ut_get_node_name(obj_desc->mutex.node), 399 ACPI_CAST_PTR(void, owner_thread->thread_id))); 400 return_ACPI_STATUS(AE_AML_NOT_OWNER); 401 } 402 403 /* 404 * The sync level of the mutex must be equal to the current sync level. In 405 * other words, the current level means that at least one mutex at that 406 * level is currently being held. Attempting to release a mutex of a 407 * different level can only mean that the mutex ordering rule is being 408 * violated. This behavior is clarified in ACPI 4.0 specification. 409 */ 410 if (obj_desc->mutex.sync_level != owner_thread->current_sync_level) { 411 ACPI_ERROR((AE_INFO, 412 "Cannot release Mutex [%4.4s], SyncLevel mismatch: mutex %u current %u", 413 acpi_ut_get_node_name(obj_desc->mutex.node), 414 obj_desc->mutex.sync_level, 415 walk_state->thread->current_sync_level)); 416 return_ACPI_STATUS(AE_AML_MUTEX_ORDER); 417 } 418 419 /* 420 * Get the previous sync_level from the head of the acquired mutex list. 421 * This handles the case where several mutexes at the same level have been 422 * acquired, but are not released in reverse order. 423 */ 424 previous_sync_level = 425 owner_thread->acquired_mutex_list->mutex.original_sync_level; 426 427 status = acpi_ex_release_mutex_object(obj_desc); 428 if (ACPI_FAILURE(status)) { 429 return_ACPI_STATUS(status); 430 } 431 432 if (obj_desc->mutex.acquisition_depth == 0) { 433 434 /* Restore the previous sync_level */ 435 436 owner_thread->current_sync_level = previous_sync_level; 437 } 438 439 return_ACPI_STATUS(status); 440} 441 442/******************************************************************************* 443 * 444 * FUNCTION: acpi_ex_release_all_mutexes 445 * 446 * PARAMETERS: Thread - Current executing thread object 447 * 448 * RETURN: Status 449 * 450 * DESCRIPTION: Release all mutexes held by this thread 451 * 452 * NOTE: This function is called as the thread is exiting the interpreter. 453 * Mutexes are not released when an individual control method is exited, but 454 * only when the parent thread actually exits the interpreter. This allows one 455 * method to acquire a mutex, and a different method to release it, as long as 456 * this is performed underneath a single parent control method. 457 * 458 ******************************************************************************/ 459 460void acpi_ex_release_all_mutexes(struct acpi_thread_state *thread) 461{ 462 union acpi_operand_object *next = thread->acquired_mutex_list; 463 union acpi_operand_object *obj_desc; 464 465 ACPI_FUNCTION_ENTRY(); 466 467 /* Traverse the list of owned mutexes, releasing each one */ 468 469 while (next) { 470 obj_desc = next; 471 next = obj_desc->mutex.next; 472 473 obj_desc->mutex.prev = NULL; 474 obj_desc->mutex.next = NULL; 475 obj_desc->mutex.acquisition_depth = 0; 476 477 /* Release the mutex, special case for Global Lock */ 478 479 if (obj_desc == acpi_gbl_global_lock_mutex) { 480 481 /* Ignore errors */ 482 483 (void)acpi_ev_release_global_lock(); 484 } else { 485 acpi_os_release_mutex(obj_desc->mutex.os_mutex); 486 } 487 488 /* Mark mutex unowned */ 489 490 obj_desc->mutex.owner_thread = NULL; 491 obj_desc->mutex.thread_id = NULL; 492 493 /* Update Thread sync_level (Last mutex is the important one) */ 494 495 thread->current_sync_level = 496 obj_desc->mutex.original_sync_level; 497 } 498} 499