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 - 2005, 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
  46 #include <acpi/acpi.h>
  47 #include <acpi/acinterp.h>
  48
  49 #define _COMPONENT          ACPI_EXECUTER
  50          ACPI_MODULE_NAME    ("exmutex")
  51
  52 /* Local prototypes */
  53
  54 static void
  55 acpi_ex_link_mutex (
  56         union acpi_operand_object       *obj_desc,
  57         struct acpi_thread_state        *thread);
  58
  59
  60 /*******************************************************************************
  61  *
  62  * FUNCTION:    acpi_ex_unlink_mutex
  63  *
  64  * PARAMETERS:  obj_desc            - The mutex to be unlinked
  65  *
  66  * RETURN:      None
  67  *
  68  * DESCRIPTION: Remove a mutex from the "acquired_mutex" list
  69  *
  70  ******************************************************************************/
  71
  72 void
  73 acpi_ex_unlink_mutex (
  74         union acpi_operand_object       *obj_desc)
  75 {
  76         struct acpi_thread_state        *thread = obj_desc->mutex.owner_thread;
  77
  78
  79         if (!thread) {
  80                 return;
  81         }
  82
  83         /* Doubly linked list */
  84
  85         if (obj_desc->mutex.next) {
  86                 (obj_desc->mutex.next)->mutex.prev = obj_desc->mutex.prev;
  87         }
  88
  89         if (obj_desc->mutex.prev) {
  90                 (obj_desc->mutex.prev)->mutex.next = obj_desc->mutex.next;
  91         }
  92         else {
  93                 thread->acquired_mutex_list = obj_desc->mutex.next;
  94         }
  95 }
  96
  97
  98 /*******************************************************************************
  99  *
 100  * FUNCTION:    acpi_ex_link_mutex
 101  *
 102  * PARAMETERS:  obj_desc        - The mutex to be linked
 103  *              Thread          - Current executing thread object
 104  *
 105  * RETURN:      None
 106  *
 107  * DESCRIPTION: Add a mutex to the "acquired_mutex" list for this walk
 108  *
 109  ******************************************************************************/
 110
 111 static void
 112 acpi_ex_link_mutex (
 113         union acpi_operand_object       *obj_desc,
 114         struct acpi_thread_state        *thread)
 115 {
 116         union acpi_operand_object       *list_head;
 117
 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  *
 140  * FUNCTION:    acpi_ex_acquire_mutex
 141  *
 142  * PARAMETERS:  time_desc           - Timeout integer
 143  *              obj_desc            - Mutex object
 144  *              walk_state          - Current method execution state
 145  *
 146  * RETURN:      Status
 147  *
 148  * DESCRIPTION: Acquire an AML mutex
 149  *
 150  ******************************************************************************/
 151
 152 acpi_status
 153 acpi_ex_acquire_mutex (
 154         union acpi_operand_object       *time_desc,
 155         union acpi_operand_object       *obj_desc,
 156         struct acpi_walk_state          *walk_state)
 157 {
 158         acpi_status                     status;
 159
 160
 161         ACPI_FUNCTION_TRACE_PTR ("ex_acquire_mutex", obj_desc);
 162
 163
 164         if (!obj_desc) {
 165                 return_ACPI_STATUS (AE_BAD_PARAMETER);
 166         }
 167
 168         /* Sanity check -- we must have a valid thread ID */
 169
 170         if (!walk_state->thread) {
 171                 ACPI_REPORT_ERROR (("Cannot acquire Mutex [%4.4s], null thread info\n",
 172                         acpi_ut_get_node_name (obj_desc->mutex.node)));
 173                 return_ACPI_STATUS (AE_AML_INTERNAL);
 174         }
 175
 176         /*
 177          * Current Sync must be less than or equal to the sync level of the
 178          * mutex.  This mechanism provides some deadlock prevention
 179          */
 180         if (walk_state->thread->current_sync_level > obj_desc->mutex.sync_level) {
 181                 ACPI_REPORT_ERROR ((
 182                         "Cannot acquire Mutex [%4.4s], incorrect sync_level\n",
 183                         acpi_ut_get_node_name (obj_desc->mutex.node)));
 184                 return_ACPI_STATUS (AE_AML_MUTEX_ORDER);
 185         }
 186
 187         /* Support for multiple acquires by the owning thread */
 188
 189         if (obj_desc->mutex.owner_thread) {
 190                 /* Special case for Global Lock, allow all threads */
 191
 192                 if ((obj_desc->mutex.owner_thread->thread_id ==
 193                                 walk_state->thread->thread_id)      ||
 194                         (obj_desc->mutex.semaphore ==
 195                                 acpi_gbl_global_lock_semaphore)) {
 196                         /*
 197                          * The mutex is already owned by this thread,
 198                          * just increment the acquisition depth
 199                          */
 200                         obj_desc->mutex.acquisition_depth++;
 201                         return_ACPI_STATUS (AE_OK);
 202                 }
 203         }
 204
 205         /* Acquire the mutex, wait if necessary */
 206
 207         status = acpi_ex_system_acquire_mutex (time_desc, obj_desc);
 208         if (ACPI_FAILURE (status)) {
 209                 /* Includes failure from a timeout on time_desc */
 210
 211                 return_ACPI_STATUS (status);
 212         }
 213
 214         /* Have the mutex: update mutex and walk info and save the sync_level */
 215
 216         obj_desc->mutex.owner_thread     = walk_state->thread;
 217         obj_desc->mutex.acquisition_depth = 1;
 218         obj_desc->mutex.original_sync_level = walk_state->thread->current_sync_level;
 219
 220         walk_state->thread->current_sync_level = obj_desc->mutex.sync_level;
 221
 222         /* Link the mutex to the current thread for force-unlock at method exit */
 223
 224         acpi_ex_link_mutex (obj_desc, walk_state->thread);
 225
 226         return_ACPI_STATUS (AE_OK);
 227 }
 228
 229
 230 /*******************************************************************************
 231  *
 232  * FUNCTION:    acpi_ex_release_mutex
 233  *
 234  * PARAMETERS:  obj_desc            - The object descriptor for this op
 235  *              walk_state          - Current method execution state
 236  *
 237  * RETURN:      Status
 238  *
 239  * DESCRIPTION: Release a previously acquired Mutex.
 240  *
 241  ******************************************************************************/
 242
 243 acpi_status
 244 acpi_ex_release_mutex (
 245         union acpi_operand_object       *obj_desc,
 246         struct acpi_walk_state          *walk_state)
 247 {
 248         acpi_status                     status;
 249
 250
 251         ACPI_FUNCTION_TRACE ("ex_release_mutex");
 252
 253
 254         if (!obj_desc) {
 255                 return_ACPI_STATUS (AE_BAD_PARAMETER);
 256         }
 257
 258         /* The mutex must have been previously acquired in order to release it */
 259
 260         if (!obj_desc->mutex.owner_thread) {
 261                 ACPI_REPORT_ERROR (("Cannot release Mutex [%4.4s], not acquired\n",
 262                                 acpi_ut_get_node_name (obj_desc->mutex.node)));
 263                 return_ACPI_STATUS (AE_AML_MUTEX_NOT_ACQUIRED);
 264         }
 265
 266         /* Sanity check -- we must have a valid thread ID */
 267
 268         if (!walk_state->thread) {
 269                 ACPI_REPORT_ERROR (("Cannot release Mutex [%4.4s], null thread info\n",
 270                                 acpi_ut_get_node_name (obj_desc->mutex.node)));
 271                 return_ACPI_STATUS (AE_AML_INTERNAL);
 272         }
 273
 274         /*
 275          * The Mutex is owned, but this thread must be the owner.
 276          * Special case for Global Lock, any thread can release
 277          */
 278         if ((obj_desc->mutex.owner_thread->thread_id != walk_state->thread->thread_id) &&
 279                 (obj_desc->mutex.semaphore != acpi_gbl_global_lock_semaphore)) {
 280                 ACPI_REPORT_ERROR ((
 281                         "Thread %X cannot release Mutex [%4.4s] acquired by thread %X\n",
 282                         walk_state->thread->thread_id,
 283                         acpi_ut_get_node_name (obj_desc->mutex.node),
 284                         obj_desc->mutex.owner_thread->thread_id));
 285                 return_ACPI_STATUS (AE_AML_NOT_OWNER);
 286         }
 287
 288         /*
 289          * The sync level of the mutex must be less than or
 290          * equal to the current sync level
 291          */
 292         if (obj_desc->mutex.sync_level > walk_state->thread->current_sync_level) {
 293                 ACPI_REPORT_ERROR ((
 294                         "Cannot release Mutex [%4.4s], incorrect sync_level\n",
 295                         acpi_ut_get_node_name (obj_desc->mutex.node)));
 296                 return_ACPI_STATUS (AE_AML_MUTEX_ORDER);
 297         }
 298
 299         /* Match multiple Acquires with multiple Releases */
 300
 301         obj_desc->mutex.acquisition_depth--;
 302         if (obj_desc->mutex.acquisition_depth != 0) {
 303                 /* Just decrement the depth and return */
 304
 305                 return_ACPI_STATUS (AE_OK);
 306         }
 307
 308         /* Unlink the mutex from the owner's list */
 309
 310         acpi_ex_unlink_mutex (obj_desc);
 311
 312         /* Release the mutex */
 313
 314         status = acpi_ex_system_release_mutex (obj_desc);
 315
 316         /* Update the mutex and walk state, restore sync_level before acquire */
 317
 318         obj_desc->mutex.owner_thread = NULL;
 319         walk_state->thread->current_sync_level = obj_desc->mutex.original_sync_level;
 320
 321         return_ACPI_STATUS (status);
 322 }
 323
 324
 325 /*******************************************************************************
 326  *
 327  * FUNCTION:    acpi_ex_release_all_mutexes
 328  *
 329  * PARAMETERS:  Thread          - Current executing thread object
 330  *
 331  * RETURN:      Status
 332  *
 333  * DESCRIPTION: Release all mutexes held by this thread
 334  *
 335  ******************************************************************************/
 336
 337 void
 338 acpi_ex_release_all_mutexes (
 339         struct acpi_thread_state        *thread)
 340 {
 341         union acpi_operand_object       *next = thread->acquired_mutex_list;
 342         union acpi_operand_object       *this;
 343         acpi_status                     status;
 344
 345
 346         ACPI_FUNCTION_ENTRY ();
 347
 348
 349         /* Traverse the list of owned mutexes, releasing each one */
 350
 351         while (next) {
 352                 this = next;
 353                 next = this->mutex.next;
 354
 355                 this->mutex.acquisition_depth = 1;
 356                 this->mutex.prev             = NULL;
 357                 this->mutex.next             = NULL;
 358
 359                  /* Release the mutex */
 360
 361                 status = acpi_ex_system_release_mutex (this);
 362                 if (ACPI_FAILURE (status)) {
 363                         continue;
 364                 }
 365
 366                 /* Mark mutex unowned */
 367
 368                 this->mutex.owner_thread = NULL;
 369
 370                 /* Update Thread sync_level (Last mutex is the important one) */
 371
 372                 thread->current_sync_level = this->mutex.original_sync_level;
 373         }
 374 }
 375
 376