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1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.02/******************************************************************************3 *4 * Module Name: exmutex - ASL Mutex Acquire/Release functions5 *6 * Copyright (C) 2000 - 2023, Intel Corp.7 *8 *****************************************************************************/9 10#include <acpi/acpi.h>11#include "accommon.h"12#include "acinterp.h"13#include "acevents.h"14 15#define _COMPONENT ACPI_EXECUTER16ACPI_MODULE_NAME("exmutex")17 18/* Local prototypes */19static void20acpi_ex_link_mutex(union acpi_operand_object *obj_desc,21 struct acpi_thread_state *thread);22 23/*******************************************************************************24 *25 * FUNCTION: acpi_ex_unlink_mutex26 *27 * PARAMETERS: obj_desc - The mutex to be unlinked28 *29 * RETURN: None30 *31 * DESCRIPTION: Remove a mutex from the "AcquiredMutex" list32 *33 ******************************************************************************/34 35void acpi_ex_unlink_mutex(union acpi_operand_object *obj_desc)36{37 struct acpi_thread_state *thread = obj_desc->mutex.owner_thread;38 39 if (!thread) {40 return;41 }42 43 /* Doubly linked list */44 45 if (obj_desc->mutex.next) {46 (obj_desc->mutex.next)->mutex.prev = obj_desc->mutex.prev;47 }48 49 if (obj_desc->mutex.prev) {50 (obj_desc->mutex.prev)->mutex.next = obj_desc->mutex.next;51 52 /*53 * Migrate the previous sync level associated with this mutex to54 * the previous mutex on the list so that it may be preserved.55 * This handles the case where several mutexes have been acquired56 * at the same level, but are not released in opposite order.57 */58 (obj_desc->mutex.prev)->mutex.original_sync_level =59 obj_desc->mutex.original_sync_level;60 } else {61 thread->acquired_mutex_list = obj_desc->mutex.next;62 }63}64 65/*******************************************************************************66 *67 * FUNCTION: acpi_ex_link_mutex68 *69 * PARAMETERS: obj_desc - The mutex to be linked70 * thread - Current executing thread object71 *72 * RETURN: None73 *74 * DESCRIPTION: Add a mutex to the "AcquiredMutex" list for this walk75 *76 ******************************************************************************/77 78static void79acpi_ex_link_mutex(union acpi_operand_object *obj_desc,80 struct acpi_thread_state *thread)81{82 union acpi_operand_object *list_head;83 84 list_head = thread->acquired_mutex_list;85 86 /* This object will be the first object in the list */87 88 obj_desc->mutex.prev = NULL;89 obj_desc->mutex.next = list_head;90 91 /* Update old first object to point back to this object */92 93 if (list_head) {94 list_head->mutex.prev = obj_desc;95 }96 97 /* Update list head */98 99 thread->acquired_mutex_list = obj_desc;100}101 102/*******************************************************************************103 *104 * FUNCTION: acpi_ex_acquire_mutex_object105 *106 * PARAMETERS: timeout - Timeout in milliseconds107 * obj_desc - Mutex object108 * thread_id - Current thread state109 *110 * RETURN: Status111 *112 * DESCRIPTION: Acquire an AML mutex, low-level interface. Provides a common113 * path that supports multiple acquires by the same thread.114 *115 * MUTEX: Interpreter must be locked116 *117 * NOTE: This interface is called from three places:118 * 1) From acpi_ex_acquire_mutex, via an AML Acquire() operator119 * 2) From acpi_ex_acquire_global_lock when an AML Field access requires the120 * global lock121 * 3) From the external interface, acpi_acquire_global_lock122 *123 ******************************************************************************/124 125acpi_status126acpi_ex_acquire_mutex_object(u16 timeout,127 union acpi_operand_object *obj_desc,128 acpi_thread_id thread_id)129{130 acpi_status status;131 132 ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex_object, obj_desc);133 134 if (!obj_desc) {135 return_ACPI_STATUS(AE_BAD_PARAMETER);136 }137 138 /* Support for multiple acquires by the owning thread */139 140 if (obj_desc->mutex.thread_id == thread_id) {141 /*142 * The mutex is already owned by this thread, just increment the143 * acquisition depth144 */145 obj_desc->mutex.acquisition_depth++;146 return_ACPI_STATUS(AE_OK);147 }148 149 /* Acquire the mutex, wait if necessary. Special case for Global Lock */150 151 if (obj_desc == acpi_gbl_global_lock_mutex) {152 status = acpi_ev_acquire_global_lock(timeout);153 } else {154 status =155 acpi_ex_system_wait_mutex(obj_desc->mutex.os_mutex,156 timeout);157 }158 159 if (ACPI_FAILURE(status)) {160 161 /* Includes failure from a timeout on time_desc */162 163 return_ACPI_STATUS(status);164 }165 166 /* Acquired the mutex: update mutex object */167 168 obj_desc->mutex.thread_id = thread_id;169 obj_desc->mutex.acquisition_depth = 1;170 obj_desc->mutex.original_sync_level = 0;171 obj_desc->mutex.owner_thread = NULL; /* Used only for AML Acquire() */172 173 return_ACPI_STATUS(AE_OK);174}175 176/*******************************************************************************177 *178 * FUNCTION: acpi_ex_acquire_mutex179 *180 * PARAMETERS: time_desc - Timeout integer181 * obj_desc - Mutex object182 * walk_state - Current method execution state183 *184 * RETURN: Status185 *186 * DESCRIPTION: Acquire an AML mutex187 *188 ******************************************************************************/189 190acpi_status191acpi_ex_acquire_mutex(union acpi_operand_object *time_desc,192 union acpi_operand_object *obj_desc,193 struct acpi_walk_state *walk_state)194{195 acpi_status status;196 197 ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex, obj_desc);198 199 if (!obj_desc) {200 return_ACPI_STATUS(AE_BAD_PARAMETER);201 }202 203 /* Must have a valid thread state struct */204 205 if (!walk_state->thread) {206 ACPI_ERROR((AE_INFO,207 "Cannot acquire Mutex [%4.4s], null thread info",208 acpi_ut_get_node_name(obj_desc->mutex.node)));209 return_ACPI_STATUS(AE_AML_INTERNAL);210 }211 212 /*213 * Current sync level must be less than or equal to the sync level214 * of the mutex. This mechanism provides some deadlock prevention.215 */216 if (walk_state->thread->current_sync_level > obj_desc->mutex.sync_level) {217 ACPI_ERROR((AE_INFO,218 "Cannot acquire Mutex [%4.4s], "219 "current SyncLevel is too large (%u)",220 acpi_ut_get_node_name(obj_desc->mutex.node),221 walk_state->thread->current_sync_level));222 return_ACPI_STATUS(AE_AML_MUTEX_ORDER);223 }224 225 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,226 "Acquiring: Mutex SyncLevel %u, Thread SyncLevel %u, "227 "Depth %u TID %p\n",228 obj_desc->mutex.sync_level,229 walk_state->thread->current_sync_level,230 obj_desc->mutex.acquisition_depth,231 walk_state->thread));232 233 status = acpi_ex_acquire_mutex_object((u16)time_desc->integer.value,234 obj_desc,235 walk_state->thread->thread_id);236 237 if (ACPI_SUCCESS(status) && obj_desc->mutex.acquisition_depth == 1) {238 239 /* Save Thread object, original/current sync levels */240 241 obj_desc->mutex.owner_thread = walk_state->thread;242 obj_desc->mutex.original_sync_level =243 walk_state->thread->current_sync_level;244 walk_state->thread->current_sync_level =245 obj_desc->mutex.sync_level;246 247 /* Link the mutex to the current thread for force-unlock at method exit */248 249 acpi_ex_link_mutex(obj_desc, walk_state->thread);250 }251 252 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,253 "Acquired: Mutex SyncLevel %u, Thread SyncLevel %u, Depth %u\n",254 obj_desc->mutex.sync_level,255 walk_state->thread->current_sync_level,256 obj_desc->mutex.acquisition_depth));257 258 return_ACPI_STATUS(status);259}260 261/*******************************************************************************262 *263 * FUNCTION: acpi_ex_release_mutex_object264 *265 * PARAMETERS: obj_desc - The object descriptor for this op266 *267 * RETURN: Status268 *269 * DESCRIPTION: Release a previously acquired Mutex, low level interface.270 * Provides a common path that supports multiple releases (after271 * previous multiple acquires) by the same thread.272 *273 * MUTEX: Interpreter must be locked274 *275 * NOTE: This interface is called from three places:276 * 1) From acpi_ex_release_mutex, via an AML Acquire() operator277 * 2) From acpi_ex_release_global_lock when an AML Field access requires the278 * global lock279 * 3) From the external interface, acpi_release_global_lock280 *281 ******************************************************************************/282 283acpi_status acpi_ex_release_mutex_object(union acpi_operand_object *obj_desc)284{285 acpi_status status = AE_OK;286 287 ACPI_FUNCTION_TRACE(ex_release_mutex_object);288 289 if (obj_desc->mutex.acquisition_depth == 0) {290 return_ACPI_STATUS(AE_NOT_ACQUIRED);291 }292 293 /* Match multiple Acquires with multiple Releases */294 295 obj_desc->mutex.acquisition_depth--;296 if (obj_desc->mutex.acquisition_depth != 0) {297 298 /* Just decrement the depth and return */299 300 return_ACPI_STATUS(AE_OK);301 }302 303 if (obj_desc->mutex.owner_thread) {304 305 /* Unlink the mutex from the owner's list */306 307 acpi_ex_unlink_mutex(obj_desc);308 obj_desc->mutex.owner_thread = NULL;309 }310 311 /* Release the mutex, special case for Global Lock */312 313 if (obj_desc == acpi_gbl_global_lock_mutex) {314 status = acpi_ev_release_global_lock();315 } else {316 acpi_os_release_mutex(obj_desc->mutex.os_mutex);317 }318 319 /* Clear mutex info */320 321 obj_desc->mutex.thread_id = 0;322 return_ACPI_STATUS(status);323}324 325/*******************************************************************************326 *327 * FUNCTION: acpi_ex_release_mutex328 *329 * PARAMETERS: obj_desc - The object descriptor for this op330 * walk_state - Current method execution state331 *332 * RETURN: Status333 *334 * DESCRIPTION: Release a previously acquired Mutex.335 *336 ******************************************************************************/337 338acpi_status339acpi_ex_release_mutex(union acpi_operand_object *obj_desc,340 struct acpi_walk_state *walk_state)341{342 u8 previous_sync_level;343 struct acpi_thread_state *owner_thread;344 acpi_status status = AE_OK;345 346 ACPI_FUNCTION_TRACE(ex_release_mutex);347 348 if (!obj_desc) {349 return_ACPI_STATUS(AE_BAD_PARAMETER);350 }351 352 owner_thread = obj_desc->mutex.owner_thread;353 354 /* The mutex must have been previously acquired in order to release it */355 356 if (!owner_thread) {357 ACPI_ERROR((AE_INFO,358 "Cannot release Mutex [%4.4s], not acquired",359 acpi_ut_get_node_name(obj_desc->mutex.node)));360 return_ACPI_STATUS(AE_AML_MUTEX_NOT_ACQUIRED);361 }362 363 /* Must have a valid thread ID */364 365 if (!walk_state->thread) {366 ACPI_ERROR((AE_INFO,367 "Cannot release Mutex [%4.4s], null thread info",368 acpi_ut_get_node_name(obj_desc->mutex.node)));369 return_ACPI_STATUS(AE_AML_INTERNAL);370 }371 372 /*373 * The Mutex is owned, but this thread must be the owner.374 * Special case for Global Lock, any thread can release375 */376 if ((owner_thread->thread_id != walk_state->thread->thread_id) &&377 (obj_desc != acpi_gbl_global_lock_mutex)) {378 ACPI_ERROR((AE_INFO,379 "Thread %u cannot release Mutex [%4.4s] acquired by thread %u",380 (u32)walk_state->thread->thread_id,381 acpi_ut_get_node_name(obj_desc->mutex.node),382 (u32)owner_thread->thread_id));383 return_ACPI_STATUS(AE_AML_NOT_OWNER);384 }385 386 /*387 * The sync level of the mutex must be equal to the current sync level. In388 * other words, the current level means that at least one mutex at that389 * level is currently being held. Attempting to release a mutex of a390 * different level can only mean that the mutex ordering rule is being391 * violated. This behavior is clarified in ACPI 4.0 specification.392 */393 if (obj_desc->mutex.sync_level != owner_thread->current_sync_level) {394 ACPI_ERROR((AE_INFO,395 "Cannot release Mutex [%4.4s], SyncLevel mismatch: "396 "mutex %u current %u",397 acpi_ut_get_node_name(obj_desc->mutex.node),398 obj_desc->mutex.sync_level,399 walk_state->thread->current_sync_level));400 return_ACPI_STATUS(AE_AML_MUTEX_ORDER);401 }402 403 /*404 * Get the previous sync_level from the head of the acquired mutex list.405 * This handles the case where several mutexes at the same level have been406 * acquired, but are not released in reverse order.407 */408 previous_sync_level =409 owner_thread->acquired_mutex_list->mutex.original_sync_level;410 411 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,412 "Releasing: Object SyncLevel %u, Thread SyncLevel %u, "413 "Prev SyncLevel %u, Depth %u TID %p\n",414 obj_desc->mutex.sync_level,415 walk_state->thread->current_sync_level,416 previous_sync_level,417 obj_desc->mutex.acquisition_depth,418 walk_state->thread));419 420 status = acpi_ex_release_mutex_object(obj_desc);421 if (ACPI_FAILURE(status)) {422 return_ACPI_STATUS(status);423 }424 425 if (obj_desc->mutex.acquisition_depth == 0) {426 427 /* Restore the previous sync_level */428 429 owner_thread->current_sync_level = previous_sync_level;430 }431 432 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,433 "Released: Object SyncLevel %u, Thread SyncLevel, %u, "434 "Prev SyncLevel %u, Depth %u\n",435 obj_desc->mutex.sync_level,436 walk_state->thread->current_sync_level,437 previous_sync_level,438 obj_desc->mutex.acquisition_depth));439 440 return_ACPI_STATUS(status);441}442 443/*******************************************************************************444 *445 * FUNCTION: acpi_ex_release_all_mutexes446 *447 * PARAMETERS: thread - Current executing thread object448 *449 * RETURN: Status450 *451 * DESCRIPTION: Release all mutexes held by this thread452 *453 * NOTE: This function is called as the thread is exiting the interpreter.454 * Mutexes are not released when an individual control method is exited, but455 * only when the parent thread actually exits the interpreter. This allows one456 * method to acquire a mutex, and a different method to release it, as long as457 * this is performed underneath a single parent control method.458 *459 ******************************************************************************/460 461void acpi_ex_release_all_mutexes(struct acpi_thread_state *thread)462{463 union acpi_operand_object *next = thread->acquired_mutex_list;464 union acpi_operand_object *obj_desc;465 466 ACPI_FUNCTION_TRACE(ex_release_all_mutexes);467 468 /* Traverse the list of owned mutexes, releasing each one */469 470 while (next) {471 obj_desc = next;472 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,473 "Mutex [%4.4s] force-release, SyncLevel %u Depth %u\n",474 obj_desc->mutex.node->name.ascii,475 obj_desc->mutex.sync_level,476 obj_desc->mutex.acquisition_depth));477 478 /* Release the mutex, special case for Global Lock */479 480 if (obj_desc == acpi_gbl_global_lock_mutex) {481 482 /* Ignore errors */483 484 (void)acpi_ev_release_global_lock();485 } else {486 acpi_os_release_mutex(obj_desc->mutex.os_mutex);487 }488 489 /* Update Thread sync_level (Last mutex is the important one) */490 491 thread->current_sync_level =492 obj_desc->mutex.original_sync_level;493 494 /* Mark mutex unowned */495 496 next = obj_desc->mutex.next;497 498 obj_desc->mutex.prev = NULL;499 obj_desc->mutex.next = NULL;500 obj_desc->mutex.acquisition_depth = 0;501 obj_desc->mutex.owner_thread = NULL;502 obj_desc->mutex.thread_id = 0;503 }504 505 return_VOID;506}507