drivers/acpi/executer/exmutex.c

   1
   2 /******************************************************************************
   3  *
   4  * Module Name: exmutex - ASL Mutex Acquire/Release functions
   5  *
   6  *****************************************************************************/
   7
   8 /*
   9  * Copyright (C) 2000 - 2007, R. Byron Moore
  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 <acpi/acinterp.h>
  47 #include <acpi/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         } else {
  86                 thread->acquired_mutex_list = obj_desc->mutex.next;
  87         }
  88 }
  89
  90 /*******************************************************************************
  91  *
  92  * FUNCTION:    acpi_ex_link_mutex
  93  *
  94  * PARAMETERS:  obj_desc        - The mutex to be linked
  95  *              Thread          - Current executing thread object
  96  *
  97  * RETURN:      None
  98  *
  99  * DESCRIPTION: Add a mutex to the "AcquiredMutex" list for this walk
 100  *
 101  ******************************************************************************/
 102
 103 static void
 104 acpi_ex_link_mutex(union acpi_operand_object *obj_desc,
 105                    struct acpi_thread_state *thread)
 106 {
 107         union acpi_operand_object *list_head;
 108
 109         list_head = thread->acquired_mutex_list;
 110
 111         /* This object will be the first object in the list */
 112
 113         obj_desc->mutex.prev = NULL;
 114         obj_desc->mutex.next = list_head;
 115
 116         /* Update old first object to point back to this object */
 117
 118         if (list_head) {
 119                 list_head->mutex.prev = obj_desc;
 120         }
 121
 122         /* Update list head */
 123
 124         thread->acquired_mutex_list = obj_desc;
 125 }
 126
 127 /*******************************************************************************
 128  *
 129  * FUNCTION:    acpi_ex_acquire_mutex_object
 130  *
 131  * PARAMETERS:  time_desc           - Timeout in milliseconds
 132  *              obj_desc            - Mutex object
 133  *              Thread              - Current thread state
 134  *
 135  * RETURN:      Status
 136  *
 137  * DESCRIPTION: Acquire an AML mutex, low-level interface. Provides a common
 138  *              path that supports multiple acquires by the same thread.
 139  *
 140  * MUTEX:       Interpreter must be locked
 141  *
 142  * NOTE: This interface is called from three places:
 143  * 1) From acpi_ex_acquire_mutex, via an AML Acquire() operator
 144  * 2) From acpi_ex_acquire_global_lock when an AML Field access requires the
 145  *    global lock
 146  * 3) From the external interface, acpi_acquire_global_lock
 147  *
 148  ******************************************************************************/
 149
 150 acpi_status
 151 acpi_ex_acquire_mutex_object(u16 timeout,
 152                              union acpi_operand_object *obj_desc,
 153                              acpi_thread_id thread_id)
 154 {
 155         acpi_status status;
 156
 157         ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex_object, obj_desc);
 158
 159         /* Support for multiple acquires by the owning thread */
 160
 161         if (obj_desc->mutex.thread_id == thread_id) {
 162                 /*
 163                  * The mutex is already owned by this thread, just increment the
 164                  * acquisition depth
 165                  */
 166                 obj_desc->mutex.acquisition_depth++;
 167                 return_ACPI_STATUS(AE_OK);
 168         }
 169
 170         /* Acquire the mutex, wait if necessary. Special case for Global Lock */
 171
 172         if (obj_desc == acpi_gbl_global_lock_mutex) {
 173                 status = acpi_ev_acquire_global_lock(timeout);
 174         } else {
 175                 status = acpi_ex_system_wait_mutex(obj_desc->mutex.os_mutex,
 176                                                    timeout);
 177         }
 178
 179         if (ACPI_FAILURE(status)) {
 180
 181                 /* Includes failure from a timeout on time_desc */
 182
 183                 return_ACPI_STATUS(status);
 184         }
 185
 186         /* Acquired the mutex: update mutex object */
 187
 188         obj_desc->mutex.thread_id = thread_id;
 189         obj_desc->mutex.acquisition_depth = 1;
 190         obj_desc->mutex.original_sync_level = 0;
 191         obj_desc->mutex.owner_thread = NULL;    /* Used only for AML Acquire() */
 192
 193         return_ACPI_STATUS(AE_OK);
 194 }
 195
 196 /*******************************************************************************
 197  *
 198  * FUNCTION:    acpi_ex_acquire_mutex
 199  *
 200  * PARAMETERS:  time_desc           - Timeout integer
 201  *              obj_desc            - Mutex object
 202  *              walk_state          - Current method execution state
 203  *
 204  * RETURN:      Status
 205  *
 206  * DESCRIPTION: Acquire an AML mutex
 207  *
 208  ******************************************************************************/
 209
 210 acpi_status
 211 acpi_ex_acquire_mutex(union acpi_operand_object *time_desc,
 212                       union acpi_operand_object *obj_desc,
 213                       struct acpi_walk_state *walk_state)
 214 {
 215         acpi_status status;
 216
 217         ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex, obj_desc);
 218
 219         if (!obj_desc) {
 220                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 221         }
 222
 223         /* Must have a valid thread ID */
 224
 225         if (!walk_state->thread) {
 226                 ACPI_ERROR((AE_INFO,
 227                             "Cannot acquire Mutex [%4.4s], null thread info",
 228                             acpi_ut_get_node_name(obj_desc->mutex.node)));
 229                 return_ACPI_STATUS(AE_AML_INTERNAL);
 230         }
 231
 232         /*
 233          * Current sync level must be less than or equal to the sync level of the
 234          * mutex. This mechanism provides some deadlock prevention
 235          */
 236         if (walk_state->thread->current_sync_level > obj_desc->mutex.sync_level) {
 237                 ACPI_ERROR((AE_INFO,
 238                             "Cannot acquire Mutex [%4.4s], current SyncLevel is too large (%d)",
 239                             acpi_ut_get_node_name(obj_desc->mutex.node),
 240                             walk_state->thread->current_sync_level));
 241                 return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
 242         }
 243
 244         status = acpi_ex_acquire_mutex_object((u16) time_desc->integer.value,
 245                                               obj_desc,
 246                                               walk_state->thread->thread_id);
 247         if (ACPI_SUCCESS(status) && obj_desc->mutex.acquisition_depth == 1) {
 248
 249                 /* Save Thread object, original/current sync levels */
 250
 251                 obj_desc->mutex.owner_thread = walk_state->thread;
 252                 obj_desc->mutex.original_sync_level =
 253                     walk_state->thread->current_sync_level;
 254                 walk_state->thread->current_sync_level =
 255                     obj_desc->mutex.sync_level;
 256
 257                 /* Link the mutex to the current thread for force-unlock at method exit */
 258
 259                 acpi_ex_link_mutex(obj_desc, walk_state->thread);
 260         }
 261
 262         return_ACPI_STATUS(status);
 263 }
 264
 265 /*******************************************************************************
 266  *
 267  * FUNCTION:    acpi_ex_release_mutex_object
 268  *
 269  * PARAMETERS:  obj_desc            - The object descriptor for this op
 270  *
 271  * RETURN:      Status
 272  *
 273  * DESCRIPTION: Release a previously acquired Mutex, low level interface.
 274  *              Provides a common path that supports multiple releases (after
 275  *              previous multiple acquires) by the same thread.
 276  *
 277  * MUTEX:       Interpreter must be locked
 278  *
 279  * NOTE: This interface is called from three places:
 280  * 1) From acpi_ex_release_mutex, via an AML Acquire() operator
 281  * 2) From acpi_ex_release_global_lock when an AML Field access requires the
 282  *    global lock
 283  * 3) From the external interface, acpi_release_global_lock
 284  *
 285  ******************************************************************************/
 286
 287 acpi_status acpi_ex_release_mutex_object(union acpi_operand_object *obj_desc)
 288 {
 289         acpi_status status = AE_OK;
 290
 291         ACPI_FUNCTION_TRACE(ex_release_mutex_object);
 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_mutex
 328  *
 329  * PARAMETERS:  obj_desc            - The object descriptor for this op
 330  *              walk_state          - Current method execution state
 331  *
 332  * RETURN:      Status
 333  *
 334  * DESCRIPTION: Release a previously acquired Mutex.
 335  *
 336  ******************************************************************************/
 337
 338 acpi_status
 339 acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
 340                       struct acpi_walk_state *walk_state)
 341 {
 342         acpi_status status = AE_OK;
 343
 344         ACPI_FUNCTION_TRACE(ex_release_mutex);
 345
 346         if (!obj_desc) {
 347                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 348         }
 349
 350         /* The mutex must have been previously acquired in order to release it */
 351
 352         if (!obj_desc->mutex.owner_thread) {
 353                 ACPI_ERROR((AE_INFO,
 354                             "Cannot release Mutex [%4.4s], not acquired",
 355                             acpi_ut_get_node_name(obj_desc->mutex.node)));
 356                 return_ACPI_STATUS(AE_AML_MUTEX_NOT_ACQUIRED);
 357         }
 358
 359         /*
 360          * The Mutex is owned, but this thread must be the owner.
 361          * Special case for Global Lock, any thread can release
 362          */
 363         if ((obj_desc->mutex.owner_thread->thread_id !=
 364              walk_state->thread->thread_id)
 365             && (obj_desc != acpi_gbl_global_lock_mutex)) {
 366                 ACPI_ERROR((AE_INFO,
 367                             "Thread %lX cannot release Mutex [%4.4s] acquired by thread %lX",
 368                             (unsigned long)walk_state->thread->thread_id,
 369                             acpi_ut_get_node_name(obj_desc->mutex.node),
 370                             (unsigned long)obj_desc->mutex.owner_thread->
 371                             thread_id));
 372                 return_ACPI_STATUS(AE_AML_NOT_OWNER);
 373         }
 374
 375         /* Must have a valid thread ID */
 376
 377         if (!walk_state->thread) {
 378                 ACPI_ERROR((AE_INFO,
 379                             "Cannot release Mutex [%4.4s], null thread info",
 380                             acpi_ut_get_node_name(obj_desc->mutex.node)));
 381                 return_ACPI_STATUS(AE_AML_INTERNAL);
 382         }
 383
 384         /*
 385          * The sync level of the mutex must be less than or equal to the current
 386          * sync level
 387          */
 388         if (obj_desc->mutex.sync_level > walk_state->thread->current_sync_level) {
 389                 ACPI_ERROR((AE_INFO,
 390                             "Cannot release Mutex [%4.4s], incorrect SyncLevel",
 391                             acpi_ut_get_node_name(obj_desc->mutex.node)));
 392                 return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
 393         }
 394
 395         status = acpi_ex_release_mutex_object(obj_desc);
 396
 397         /* Restore the original sync_level */
 398
 399         walk_state->thread->current_sync_level =
 400             obj_desc->mutex.original_sync_level;
 401         return_ACPI_STATUS(status);
 402 }
 403
 404 /*******************************************************************************
 405  *
 406  * FUNCTION:    acpi_ex_release_all_mutexes
 407  *
 408  * PARAMETERS:  Thread          - Current executing thread object
 409  *
 410  * RETURN:      Status
 411  *
 412  * DESCRIPTION: Release all mutexes held by this thread
 413  *
 414  * NOTE: This function is called as the thread is exiting the interpreter.
 415  * Mutexes are not released when an individual control method is exited, but
 416  * only when the parent thread actually exits the interpreter. This allows one
 417  * method to acquire a mutex, and a different method to release it, as long as
 418  * this is performed underneath a single parent control method.
 419  *
 420  ******************************************************************************/
 421
 422 void acpi_ex_release_all_mutexes(struct acpi_thread_state *thread)
 423 {
 424         union acpi_operand_object *next = thread->acquired_mutex_list;
 425         union acpi_operand_object *obj_desc;
 426
 427         ACPI_FUNCTION_ENTRY();
 428
 429         /* Traverse the list of owned mutexes, releasing each one */
 430
 431         while (next) {
 432                 obj_desc = next;
 433                 next = obj_desc->mutex.next;
 434
 435                 obj_desc->mutex.prev = NULL;
 436                 obj_desc->mutex.next = NULL;
 437                 obj_desc->mutex.acquisition_depth = 0;
 438
 439                 /* Release the mutex, special case for Global Lock */
 440
 441                 if (obj_desc == acpi_gbl_global_lock_mutex) {
 442
 443                         /* Ignore errors */
 444
 445                         (void)acpi_ev_release_global_lock();
 446                 } else {
 447                         acpi_os_release_mutex(obj_desc->mutex.os_mutex);
 448                 }
 449
 450                 /* Mark mutex unowned */
 451
 452                 obj_desc->mutex.owner_thread = NULL;
 453                 obj_desc->mutex.thread_id = 0;
 454
 455                 /* Update Thread sync_level (Last mutex is the important one) */
 456
 457                 thread->current_sync_level =
 458                     obj_desc->mutex.original_sync_level;
 459         }
 460 }