err.no Git - linux-2.6/blob - 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                           struct acpi_thread_state *thread)
  71 {
  72         if (!thread) {
  73                 return;
  74         }
  75
  76         /* Doubly linked list */
  77
  78         if (obj_desc->mutex.next) {
  79                 (obj_desc->mutex.next)->mutex.prev = obj_desc->mutex.prev;
  80         }
  81
  82         if (obj_desc->mutex.prev) {
  83                 (obj_desc->mutex.prev)->mutex.next = obj_desc->mutex.next;
  84         } else {
  85                 thread->acquired_mutex_list = obj_desc->mutex.next;
  86         }
  87 }
  88
  89 /*******************************************************************************
  90  *
  91  * FUNCTION:    acpi_ex_link_mutex
  92  *
  93  * PARAMETERS:  obj_desc        - The mutex to be linked
  94  *              Thread          - Current executing thread object
  95  *
  96  * RETURN:      None
  97  *
  98  * DESCRIPTION: Add a mutex to the "AcquiredMutex" list for this walk
  99  *
 100  ******************************************************************************/
 101
 102 static void
 103 acpi_ex_link_mutex(union acpi_operand_object *obj_desc,
 104                    struct acpi_thread_state *thread)
 105 {
 106         union acpi_operand_object *list_head;
 107
 108         list_head = thread->acquired_mutex_list;
 109
 110         /* This object will be the first object in the list */
 111
 112         obj_desc->mutex.prev = NULL;
 113         obj_desc->mutex.next = list_head;
 114
 115         /* Update old first object to point back to this object */
 116
 117         if (list_head) {
 118                 list_head->mutex.prev = obj_desc;
 119         }
 120
 121         /* Update list head */
 122
 123         thread->acquired_mutex_list = obj_desc;
 124 }
 125
 126 /*******************************************************************************
 127  *
 128  * FUNCTION:    acpi_ex_acquire_mutex
 129  *
 130  * PARAMETERS:  time_desc           - Timeout integer
 131  *              obj_desc            - Mutex object
 132  *              walk_state          - Current method execution state
 133  *
 134  * RETURN:      Status
 135  *
 136  * DESCRIPTION: Acquire an AML mutex
 137  *
 138  ******************************************************************************/
 139
 140 acpi_status
 141 acpi_ex_acquire_mutex(union acpi_operand_object *time_desc,
 142                       union acpi_operand_object *obj_desc,
 143                       struct acpi_walk_state *walk_state)
 144 {
 145         acpi_status status;
 146
 147         ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex, obj_desc);
 148
 149         if (!obj_desc) {
 150                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 151         }
 152
 153         /* Sanity check: we must have a valid thread ID */
 154
 155         if (!walk_state->thread) {
 156                 ACPI_ERROR((AE_INFO,
 157                             "Cannot acquire Mutex [%4.4s], null thread info",
 158                             acpi_ut_get_node_name(obj_desc->mutex.node)));
 159                 return_ACPI_STATUS(AE_AML_INTERNAL);
 160         }
 161
 162         /*
 163          * Current Sync must be less than or equal to the sync level of the
 164          * mutex. This mechanism provides some deadlock prevention
 165          */
 166         if (walk_state->thread->current_sync_level > obj_desc->mutex.sync_level) {
 167                 ACPI_ERROR((AE_INFO,
 168                             "Cannot acquire Mutex [%4.4s], current SyncLevel is too large (%d)",
 169                             acpi_ut_get_node_name(obj_desc->mutex.node),
 170                             walk_state->thread->current_sync_level));
 171                 return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
 172         }
 173
 174         /* Support for multiple acquires by the owning thread */
 175
 176         if (obj_desc->mutex.owner_thread_id == acpi_os_get_thread_id()) {
 177                 /*
 178                  * The mutex is already owned by this thread, just increment the
 179                  * acquisition depth
 180                  */
 181                 obj_desc->mutex.acquisition_depth++;
 182                 return_ACPI_STATUS(AE_OK);
 183         }
 184
 185         /* Acquire the mutex, wait if necessary. Special case for Global Lock */
 186
 187         if (obj_desc->mutex.os_mutex == acpi_gbl_global_lock_mutex) {
 188                 status =
 189                     acpi_ev_acquire_global_lock((u16) time_desc->integer.value);
 190         } else {
 191                 status = acpi_ex_system_wait_mutex(obj_desc->mutex.os_mutex,
 192                                                    (u16) time_desc->integer.
 193                                                    value);
 194         }
 195
 196         if (ACPI_FAILURE(status)) {
 197
 198                 /* Includes failure from a timeout on time_desc */
 199
 200                 return_ACPI_STATUS(status);
 201         }
 202
 203         /* Have the mutex: update mutex and walk info and save the sync_level */
 204
 205         obj_desc->mutex.owner_thread_id = acpi_os_get_thread_id();
 206         obj_desc->mutex.acquisition_depth = 1;
 207         obj_desc->mutex.original_sync_level =
 208             walk_state->thread->current_sync_level;
 209
 210         walk_state->thread->current_sync_level = obj_desc->mutex.sync_level;
 211
 212         /* Link the mutex to the current thread for force-unlock at method exit */
 213
 214         acpi_ex_link_mutex(obj_desc, walk_state->thread);
 215         return_ACPI_STATUS(AE_OK);
 216 }
 217
 218 /*******************************************************************************
 219  *
 220  * FUNCTION:    acpi_ex_release_mutex
 221  *
 222  * PARAMETERS:  obj_desc            - The object descriptor for this op
 223  *              walk_state          - Current method execution state
 224  *
 225  * RETURN:      Status
 226  *
 227  * DESCRIPTION: Release a previously acquired Mutex.
 228  *
 229  ******************************************************************************/
 230
 231 acpi_status
 232 acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
 233                       struct acpi_walk_state *walk_state)
 234 {
 235         acpi_status status = AE_OK;
 236
 237         ACPI_FUNCTION_TRACE(ex_release_mutex);
 238
 239         if (!obj_desc) {
 240                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 241         }
 242
 243         /* The mutex must have been previously acquired in order to release it */
 244
 245         if (!obj_desc->mutex.owner_thread_id) {
 246                 ACPI_ERROR((AE_INFO,
 247                             "Cannot release Mutex [%4.4s], not acquired",
 248                             acpi_ut_get_node_name(obj_desc->mutex.node)));
 249                 return_ACPI_STATUS(AE_AML_MUTEX_NOT_ACQUIRED);
 250         }
 251
 252         /* Sanity check: we must have a valid thread ID */
 253
 254         if (!walk_state->thread) {
 255                 ACPI_ERROR((AE_INFO,
 256                             "Cannot release Mutex [%4.4s], null thread info",
 257                             acpi_ut_get_node_name(obj_desc->mutex.node)));
 258                 return_ACPI_STATUS(AE_AML_INTERNAL);
 259         }
 260
 261         /*
 262          * The Mutex is owned, but this thread must be the owner.
 263          * Special case for Global Lock, any thread can release
 264          */
 265         if ((obj_desc->mutex.owner_thread_id !=
 266              walk_state->thread->thread_id)
 267             && (obj_desc->mutex.os_mutex != acpi_gbl_global_lock_mutex)) {
 268                 ACPI_ERROR((AE_INFO,
 269                             "Thread %lX cannot release Mutex [%4.4s] acquired by thread %lX",
 270                             (unsigned long)walk_state->thread->thread_id,
 271                             acpi_ut_get_node_name(obj_desc->mutex.node),
 272                             (unsigned long)obj_desc->mutex.owner_thread_id));
 273                 return_ACPI_STATUS(AE_AML_NOT_OWNER);
 274         }
 275
 276         /*
 277          * The sync level of the mutex must be less than or equal to the current
 278          * sync level
 279          */
 280         if (obj_desc->mutex.sync_level > walk_state->thread->current_sync_level) {
 281                 ACPI_ERROR((AE_INFO,
 282                             "Cannot release Mutex [%4.4s], incorrect SyncLevel",
 283                             acpi_ut_get_node_name(obj_desc->mutex.node)));
 284                 return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
 285         }
 286
 287         /* Match multiple Acquires with multiple Releases */
 288
 289         obj_desc->mutex.acquisition_depth--;
 290         if (obj_desc->mutex.acquisition_depth != 0) {
 291
 292                 /* Just decrement the depth and return */
 293
 294                 return_ACPI_STATUS(AE_OK);
 295         }
 296
 297         /* Unlink the mutex from the owner's list */
 298
 299         acpi_ex_unlink_mutex(obj_desc, walk_state->thread);
 300
 301         /* Release the mutex, special case for Global Lock */
 302
 303         if (obj_desc->mutex.os_mutex == acpi_gbl_global_lock_mutex) {
 304                 status = acpi_ev_release_global_lock();
 305         } else {
 306                 acpi_os_release_mutex(obj_desc->mutex.os_mutex);
 307         }
 308
 309         /* Update the mutex and restore sync_level */
 310
 311         obj_desc->mutex.owner_thread_id = ACPI_MUTEX_NOT_ACQUIRED;
 312         walk_state->thread->current_sync_level =
 313             obj_desc->mutex.original_sync_level;
 314
 315         return_ACPI_STATUS(status);
 316 }
 317
 318 /*******************************************************************************
 319  *
 320  * FUNCTION:    acpi_ex_release_all_mutexes
 321  *
 322  * PARAMETERS:  Thread          - Current executing thread object
 323  *
 324  * RETURN:      Status
 325  *
 326  * DESCRIPTION: Release all mutexes held by this thread
 327  *
 328  * NOTE: This function is called as the thread is exiting the interpreter.
 329  * Mutexes are not released when an individual control method is exited, but
 330  * only when the parent thread actually exits the interpreter. This allows one
 331  * method to acquire a mutex, and a different method to release it, as long as
 332  * this is performed underneath a single parent control method.
 333  *
 334  ******************************************************************************/
 335
 336 void acpi_ex_release_all_mutexes(struct acpi_thread_state *thread)
 337 {
 338         union acpi_operand_object *next = thread->acquired_mutex_list;
 339         union acpi_operand_object *obj_desc;
 340
 341         ACPI_FUNCTION_ENTRY();
 342
 343         /* Traverse the list of owned mutexes, releasing each one */
 344
 345         while (next) {
 346                 obj_desc = next;
 347                 next = obj_desc->mutex.next;
 348
 349                 obj_desc->mutex.prev = NULL;
 350                 obj_desc->mutex.next = NULL;
 351                 obj_desc->mutex.acquisition_depth = 0;
 352
 353                 /* Release the mutex, special case for Global Lock */
 354
 355                 if (obj_desc->mutex.os_mutex == acpi_gbl_global_lock_mutex) {
 356
 357                         /* Ignore errors */
 358
 359                         (void)acpi_ev_release_global_lock();
 360                 } else {
 361                         acpi_os_release_mutex(obj_desc->mutex.os_mutex);
 362                 }
 363
 364                 /* Mark mutex unowned */
 365
 366                 obj_desc->mutex.owner_thread_id = ACPI_MUTEX_NOT_ACQUIRED;
 367
 368                 /* Update Thread sync_level (Last mutex is the important one) */
 369
 370                 thread->current_sync_level =
 371                     obj_desc->mutex.original_sync_level;
 372         }
 373 }