1 /****************************************************************************** 2 * 3 * Module Name: exmutex - ASL Mutex Acquire/Release functions 4 * 5 *****************************************************************************/ 6 7 /* 8 * Copyright (C) 2000 - 2012, 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 "acinterp.h" 47 #include "acevents.h" 48 49 #define _COMPONENT ACPI_EXECUTER 50 ACPI_MODULE_NAME("exmutex") 51 52 /* Local prototypes */ 53 static void 54 acpi_ex_link_mutex(union acpi_operand_object *obj_desc, 55 struct acpi_thread_state *thread); 56 57 /******************************************************************************* 58 * 59 * FUNCTION: acpi_ex_unlink_mutex 60 * 61 * PARAMETERS: obj_desc - The mutex to be unlinked 62 * 63 * RETURN: None 64 * 65 * DESCRIPTION: Remove a mutex from the "AcquiredMutex" list 66 * 67 ******************************************************************************/ 68 69 void acpi_ex_unlink_mutex(union acpi_operand_object *obj_desc) 70 { 71 struct acpi_thread_state *thread = obj_desc->mutex.owner_thread; 72 73 if (!thread) { 74 return; 75 } 76 77 /* Doubly linked list */ 78 79 if (obj_desc->mutex.next) { 80 (obj_desc->mutex.next)->mutex.prev = obj_desc->mutex.prev; 81 } 82 83 if (obj_desc->mutex.prev) { 84 (obj_desc->mutex.prev)->mutex.next = obj_desc->mutex.next; 85 86 /* 87 * Migrate the previous sync level associated with this mutex to 88 * the previous mutex on the list so that it may be preserved. 89 * This handles the case where several mutexes have been acquired 90 * at the same level, but are not released in opposite order. 91 */ 92 (obj_desc->mutex.prev)->mutex.original_sync_level = 93 obj_desc->mutex.original_sync_level; 94 } else { 95 thread->acquired_mutex_list = obj_desc->mutex.next; 96 } 97 } 98 99 /******************************************************************************* 100 * 101 * FUNCTION: acpi_ex_link_mutex 102 * 103 * PARAMETERS: obj_desc - The mutex to be linked 104 * thread - Current executing thread object 105 * 106 * RETURN: None 107 * 108 * DESCRIPTION: Add a mutex to the "AcquiredMutex" list for this walk 109 * 110 ******************************************************************************/ 111 112 static void 113 acpi_ex_link_mutex(union acpi_operand_object *obj_desc, 114 struct acpi_thread_state *thread) 115 { 116 union acpi_operand_object *list_head; 117 118 list_head = thread->acquired_mutex_list; 119 120 /* This object will be the first object in the list */ 121 122 obj_desc->mutex.prev = NULL; 123 obj_desc->mutex.next = list_head; 124 125 /* Update old first object to point back to this object */ 126 127 if (list_head) { 128 list_head->mutex.prev = obj_desc; 129 } 130 131 /* Update list head */ 132 133 thread->acquired_mutex_list = obj_desc; 134 } 135 136 /******************************************************************************* 137 * 138 * FUNCTION: acpi_ex_acquire_mutex_object 139 * 140 * PARAMETERS: timeout - Timeout in milliseconds 141 * obj_desc - Mutex object 142 * thread_id - Current thread state 143 * 144 * RETURN: Status 145 * 146 * DESCRIPTION: Acquire an AML mutex, low-level interface. Provides a common 147 * path that supports multiple acquires by the same thread. 148 * 149 * MUTEX: Interpreter must be locked 150 * 151 * NOTE: This interface is called from three places: 152 * 1) From acpi_ex_acquire_mutex, via an AML Acquire() operator 153 * 2) From acpi_ex_acquire_global_lock when an AML Field access requires the 154 * global lock 155 * 3) From the external interface, acpi_acquire_global_lock 156 * 157 ******************************************************************************/ 158 159 acpi_status 160 acpi_ex_acquire_mutex_object(u16 timeout, 161 union acpi_operand_object *obj_desc, 162 acpi_thread_id thread_id) 163 { 164 acpi_status status; 165 166 ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex_object, obj_desc); 167 168 if (!obj_desc) { 169 return_ACPI_STATUS(AE_BAD_PARAMETER); 170 } 171 172 /* Support for multiple acquires by the owning thread */ 173 174 if (obj_desc->mutex.thread_id == thread_id) { 175 /* 176 * The mutex is already owned by this thread, just increment the 177 * acquisition depth 178 */ 179 obj_desc->mutex.acquisition_depth++; 180 return_ACPI_STATUS(AE_OK); 181 } 182 183 /* Acquire the mutex, wait if necessary. Special case for Global Lock */ 184 185 if (obj_desc == acpi_gbl_global_lock_mutex) { 186 status = acpi_ev_acquire_global_lock(timeout); 187 } else { 188 status = acpi_ex_system_wait_mutex(obj_desc->mutex.os_mutex, 189 timeout); 190 } 191 192 if (ACPI_FAILURE(status)) { 193 194 /* Includes failure from a timeout on time_desc */ 195 196 return_ACPI_STATUS(status); 197 } 198 199 /* Acquired the mutex: update mutex object */ 200 201 obj_desc->mutex.thread_id = thread_id; 202 obj_desc->mutex.acquisition_depth = 1; 203 obj_desc->mutex.original_sync_level = 0; 204 obj_desc->mutex.owner_thread = NULL; /* Used only for AML Acquire() */ 205 206 return_ACPI_STATUS(AE_OK); 207 } 208 209 /******************************************************************************* 210 * 211 * FUNCTION: acpi_ex_acquire_mutex 212 * 213 * PARAMETERS: time_desc - Timeout integer 214 * obj_desc - Mutex object 215 * walk_state - Current method execution state 216 * 217 * RETURN: Status 218 * 219 * DESCRIPTION: Acquire an AML mutex 220 * 221 ******************************************************************************/ 222 223 acpi_status 224 acpi_ex_acquire_mutex(union acpi_operand_object *time_desc, 225 union acpi_operand_object *obj_desc, 226 struct acpi_walk_state *walk_state) 227 { 228 acpi_status status; 229 230 ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex, obj_desc); 231 232 if (!obj_desc) { 233 return_ACPI_STATUS(AE_BAD_PARAMETER); 234 } 235 236 /* Must have a valid thread state struct */ 237 238 if (!walk_state->thread) { 239 ACPI_ERROR((AE_INFO, 240 "Cannot acquire Mutex [%4.4s], null thread info", 241 acpi_ut_get_node_name(obj_desc->mutex.node))); 242 return_ACPI_STATUS(AE_AML_INTERNAL); 243 } 244 245 /* 246 * Current sync level must be less than or equal to the sync level of the 247 * mutex. This mechanism provides some deadlock prevention 248 */ 249 if (walk_state->thread->current_sync_level > obj_desc->mutex.sync_level) { 250 ACPI_ERROR((AE_INFO, 251 "Cannot acquire Mutex [%4.4s], current SyncLevel is too large (%u)", 252 acpi_ut_get_node_name(obj_desc->mutex.node), 253 walk_state->thread->current_sync_level)); 254 return_ACPI_STATUS(AE_AML_MUTEX_ORDER); 255 } 256 257 status = acpi_ex_acquire_mutex_object((u16) time_desc->integer.value, 258 obj_desc, 259 walk_state->thread->thread_id); 260 if (ACPI_SUCCESS(status) && obj_desc->mutex.acquisition_depth == 1) { 261 262 /* Save Thread object, original/current sync levels */ 263 264 obj_desc->mutex.owner_thread = walk_state->thread; 265 obj_desc->mutex.original_sync_level = 266 walk_state->thread->current_sync_level; 267 walk_state->thread->current_sync_level = 268 obj_desc->mutex.sync_level; 269 270 /* Link the mutex to the current thread for force-unlock at method exit */ 271 272 acpi_ex_link_mutex(obj_desc, walk_state->thread); 273 } 274 275 return_ACPI_STATUS(status); 276 } 277 278 /******************************************************************************* 279 * 280 * FUNCTION: acpi_ex_release_mutex_object 281 * 282 * PARAMETERS: obj_desc - The object descriptor for this op 283 * 284 * RETURN: Status 285 * 286 * DESCRIPTION: Release a previously acquired Mutex, low level interface. 287 * Provides a common path that supports multiple releases (after 288 * previous multiple acquires) by the same thread. 289 * 290 * MUTEX: Interpreter must be locked 291 * 292 * NOTE: This interface is called from three places: 293 * 1) From acpi_ex_release_mutex, via an AML Acquire() operator 294 * 2) From acpi_ex_release_global_lock when an AML Field access requires the 295 * global lock 296 * 3) From the external interface, acpi_release_global_lock 297 * 298 ******************************************************************************/ 299 300 acpi_status acpi_ex_release_mutex_object(union acpi_operand_object *obj_desc) 301 { 302 acpi_status status = AE_OK; 303 304 ACPI_FUNCTION_TRACE(ex_release_mutex_object); 305 306 if (obj_desc->mutex.acquisition_depth == 0) { 307 return_ACPI_STATUS(AE_NOT_ACQUIRED); 308 } 309 310 /* Match multiple Acquires with multiple Releases */ 311 312 obj_desc->mutex.acquisition_depth--; 313 if (obj_desc->mutex.acquisition_depth != 0) { 314 315 /* Just decrement the depth and return */ 316 317 return_ACPI_STATUS(AE_OK); 318 } 319 320 if (obj_desc->mutex.owner_thread) { 321 322 /* Unlink the mutex from the owner's list */ 323 324 acpi_ex_unlink_mutex(obj_desc); 325 obj_desc->mutex.owner_thread = NULL; 326 } 327 328 /* Release the mutex, special case for Global Lock */ 329 330 if (obj_desc == acpi_gbl_global_lock_mutex) { 331 status = acpi_ev_release_global_lock(); 332 } else { 333 acpi_os_release_mutex(obj_desc->mutex.os_mutex); 334 } 335 336 /* Clear mutex info */ 337 338 obj_desc->mutex.thread_id = 0; 339 return_ACPI_STATUS(status); 340 } 341 342 /******************************************************************************* 343 * 344 * FUNCTION: acpi_ex_release_mutex 345 * 346 * PARAMETERS: obj_desc - The object descriptor for this op 347 * walk_state - Current method execution state 348 * 349 * RETURN: Status 350 * 351 * DESCRIPTION: Release a previously acquired Mutex. 352 * 353 ******************************************************************************/ 354 355 acpi_status 356 acpi_ex_release_mutex(union acpi_operand_object *obj_desc, 357 struct acpi_walk_state *walk_state) 358 { 359 acpi_status status = AE_OK; 360 u8 previous_sync_level; 361 struct acpi_thread_state *owner_thread; 362 363 ACPI_FUNCTION_TRACE(ex_release_mutex); 364 365 if (!obj_desc) { 366 return_ACPI_STATUS(AE_BAD_PARAMETER); 367 } 368 369 owner_thread = obj_desc->mutex.owner_thread; 370 371 /* The mutex must have been previously acquired in order to release it */ 372 373 if (!owner_thread) { 374 ACPI_ERROR((AE_INFO, 375 "Cannot release Mutex [%4.4s], not acquired", 376 acpi_ut_get_node_name(obj_desc->mutex.node))); 377 return_ACPI_STATUS(AE_AML_MUTEX_NOT_ACQUIRED); 378 } 379 380 /* Must have a valid thread. */ 381 if (!walk_state->thread) { 382 ACPI_ERROR((AE_INFO, 383 "Cannot release Mutex [%4.4s], null thread info", 384 acpi_ut_get_node_name(obj_desc->mutex.node))); 385 return_ACPI_STATUS(AE_AML_INTERNAL); 386 } 387 388 /* 389 * The Mutex is owned, but this thread must be the owner. 390 * Special case for Global Lock, any thread can release 391 */ 392 if ((owner_thread->thread_id != walk_state->thread->thread_id) && 393 (obj_desc != acpi_gbl_global_lock_mutex)) { 394 ACPI_ERROR((AE_INFO, 395 "Thread %u cannot release Mutex [%4.4s] acquired by thread %u", 396 (u32)walk_state->thread->thread_id, 397 acpi_ut_get_node_name(obj_desc->mutex.node), 398 (u32)owner_thread->thread_id)); 399 return_ACPI_STATUS(AE_AML_NOT_OWNER); 400 } 401 402 /* 403 * The sync level of the mutex must be equal to the current sync level. In 404 * other words, the current level means that at least one mutex at that 405 * level is currently being held. Attempting to release a mutex of a 406 * different level can only mean that the mutex ordering rule is being 407 * violated. This behavior is clarified in ACPI 4.0 specification. 408 */ 409 if (obj_desc->mutex.sync_level != owner_thread->current_sync_level) { 410 ACPI_ERROR((AE_INFO, 411 "Cannot release Mutex [%4.4s], SyncLevel mismatch: mutex %u current %u", 412 acpi_ut_get_node_name(obj_desc->mutex.node), 413 obj_desc->mutex.sync_level, 414 walk_state->thread->current_sync_level)); 415 return_ACPI_STATUS(AE_AML_MUTEX_ORDER); 416 } 417 418 /* 419 * Get the previous sync_level from the head of the acquired mutex list. 420 * This handles the case where several mutexes at the same level have been 421 * acquired, but are not released in reverse order. 422 */ 423 previous_sync_level = 424 owner_thread->acquired_mutex_list->mutex.original_sync_level; 425 426 status = acpi_ex_release_mutex_object(obj_desc); 427 if (ACPI_FAILURE(status)) { 428 return_ACPI_STATUS(status); 429 } 430 431 if (obj_desc->mutex.acquisition_depth == 0) { 432 433 /* Restore the previous sync_level */ 434 435 owner_thread->current_sync_level = previous_sync_level; 436 } 437 438 return_ACPI_STATUS(status); 439 } 440 441 /******************************************************************************* 442 * 443 * FUNCTION: acpi_ex_release_all_mutexes 444 * 445 * PARAMETERS: thread - Current executing thread object 446 * 447 * RETURN: Status 448 * 449 * DESCRIPTION: Release all mutexes held by this thread 450 * 451 * NOTE: This function is called as the thread is exiting the interpreter. 452 * Mutexes are not released when an individual control method is exited, but 453 * only when the parent thread actually exits the interpreter. This allows one 454 * method to acquire a mutex, and a different method to release it, as long as 455 * this is performed underneath a single parent control method. 456 * 457 ******************************************************************************/ 458 459 void acpi_ex_release_all_mutexes(struct acpi_thread_state *thread) 460 { 461 union acpi_operand_object *next = thread->acquired_mutex_list; 462 union acpi_operand_object *obj_desc; 463 464 ACPI_FUNCTION_ENTRY(); 465 466 /* Traverse the list of owned mutexes, releasing each one */ 467 468 while (next) { 469 obj_desc = next; 470 next = obj_desc->mutex.next; 471 472 obj_desc->mutex.prev = NULL; 473 obj_desc->mutex.next = NULL; 474 obj_desc->mutex.acquisition_depth = 0; 475 476 /* Release the mutex, special case for Global Lock */ 477 478 if (obj_desc == acpi_gbl_global_lock_mutex) { 479 480 /* Ignore errors */ 481 482 (void)acpi_ev_release_global_lock(); 483 } else { 484 acpi_os_release_mutex(obj_desc->mutex.os_mutex); 485 } 486 487 /* Mark mutex unowned */ 488 489 obj_desc->mutex.owner_thread = NULL; 490 obj_desc->mutex.thread_id = 0; 491 492 /* Update Thread sync_level (Last mutex is the important one) */ 493 494 thread->current_sync_level = 495 obj_desc->mutex.original_sync_level; 496 } 497 } 498