release/src/linux/linux/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 - 2004, 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
  53 /*******************************************************************************
  54  *
  55  * FUNCTION:    acpi_ex_unlink_mutex
  56  *
  57  * PARAMETERS:  *obj_desc           - The mutex to be unlinked
  58  *
  59  * RETURN:      Status
  60  *
  61  * DESCRIPTION: Remove a mutex from the "acquired_mutex" list
  62  *
  63  ******************************************************************************/
  64
  65 void
  66 acpi_ex_unlink_mutex (
  67         union acpi_operand_object       *obj_desc)
  68 {
  69         struct acpi_thread_state        *thread = obj_desc->mutex.owner_thread;
  70
  71
  72         if (!thread) {
  73                 return;
  74         }
  75
  76         if (obj_desc->mutex.next) {
  77                 (obj_desc->mutex.next)->mutex.prev = obj_desc->mutex.prev;
  78         }
  79
  80         if (obj_desc->mutex.prev) {
  81                 (obj_desc->mutex.prev)->mutex.next = obj_desc->mutex.next;
  82         }
  83         else {
  84                 thread->acquired_mutex_list = obj_desc->mutex.next;
  85         }
  86 }
  87
  88
  89 /*******************************************************************************
  90  *
  91  * FUNCTION:    acpi_ex_link_mutex
  92  *
  93  * PARAMETERS:  *obj_desc           - The mutex to be linked
  94  *              *list_head          - head of the "acquired_mutex" list
  95  *
  96  * RETURN:      Status
  97  *
  98  * DESCRIPTION: Add a mutex to the "acquired_mutex" list for this walk
  99  *
 100  ******************************************************************************/
 101
 102 void
 103 acpi_ex_link_mutex (
 104         union acpi_operand_object       *obj_desc,
 105         struct acpi_thread_state        *thread)
 106 {
 107         union acpi_operand_object       *list_head;
 108
 109
 110         list_head = thread->acquired_mutex_list;
 111
 112         /* This object will be the first object in the list */
 113
 114         obj_desc->mutex.prev = NULL;
 115         obj_desc->mutex.next = list_head;
 116
 117         /* Update old first object to point back to this object */
 118
 119         if (list_head) {
 120                 list_head->mutex.prev = obj_desc;
 121         }
 122
 123         /* Update list head */
 124
 125         thread->acquired_mutex_list = obj_desc;
 126 }
 127
 128
 129 /*******************************************************************************
 130  *
 131  * FUNCTION:    acpi_ex_acquire_mutex
 132  *
 133  * PARAMETERS:  *time_desc          - The 'time to delay' object descriptor
 134  *              *obj_desc           - The object descriptor for this op
 135  *
 136  * RETURN:      Status
 137  *
 138  * DESCRIPTION: Acquire an AML mutex
 139  *
 140  ******************************************************************************/
 141
 142 acpi_status
 143 acpi_ex_acquire_mutex (
 144         union acpi_operand_object       *time_desc,
 145         union acpi_operand_object       *obj_desc,
 146         struct acpi_walk_state          *walk_state)
 147 {
 148         acpi_status                     status;
 149
 150
 151         ACPI_FUNCTION_TRACE_PTR ("ex_acquire_mutex", obj_desc);
 152
 153
 154         if (!obj_desc) {
 155                 return_ACPI_STATUS (AE_BAD_PARAMETER);
 156         }
 157
 158         /* Sanity check -- we must have a valid thread ID */
 159
 160         if (!walk_state->thread) {
 161                 ACPI_REPORT_ERROR (("Cannot acquire Mutex [%4.4s], null thread info\n",
 162                                 acpi_ut_get_node_name (obj_desc->mutex.node)));
 163                 return_ACPI_STATUS (AE_AML_INTERNAL);
 164         }
 165
 166         /*
 167          * Current Sync must be less than or equal to the sync level of the
 168          * mutex.  This mechanism provides some deadlock prevention
 169          */
 170         if (walk_state->thread->current_sync_level > obj_desc->mutex.sync_level) {
 171                 ACPI_REPORT_ERROR (("Cannot acquire Mutex [%4.4s], incorrect sync_level\n",
 172                                 acpi_ut_get_node_name (obj_desc->mutex.node)));
 173                 return_ACPI_STATUS (AE_AML_MUTEX_ORDER);
 174         }
 175
 176         /*
 177          * Support for multiple acquires by the owning thread
 178          */
 179         if (obj_desc->mutex.owner_thread) {
 180                 /* Special case for Global Lock, allow all threads */
 181
 182                 if ((obj_desc->mutex.owner_thread->thread_id == walk_state->thread->thread_id) ||
 183                         (obj_desc->mutex.semaphore == acpi_gbl_global_lock_semaphore)) {
 184                         /*
 185                          * The mutex is already owned by this thread,
 186                          * just increment the acquisition depth
 187                          */
 188                         obj_desc->mutex.acquisition_depth++;
 189                         return_ACPI_STATUS (AE_OK);
 190                 }
 191         }
 192
 193         /* Acquire the mutex, wait if necessary */
 194
 195         status = acpi_ex_system_acquire_mutex (time_desc, obj_desc);
 196         if (ACPI_FAILURE (status)) {
 197                 /* Includes failure from a timeout on time_desc */
 198
 199                 return_ACPI_STATUS (status);
 200         }
 201
 202         /* Have the mutex, update mutex and walk info */
 203
 204         obj_desc->mutex.owner_thread    = walk_state->thread;
 205         obj_desc->mutex.acquisition_depth = 1;
 206
 207         walk_state->thread->current_sync_level = obj_desc->mutex.sync_level;
 208
 209         /* Link the mutex to the current thread for force-unlock at method exit */
 210
 211         acpi_ex_link_mutex (obj_desc, walk_state->thread);
 212
 213         return_ACPI_STATUS (AE_OK);
 214 }
 215
 216
 217 /*******************************************************************************
 218  *
 219  * FUNCTION:    acpi_ex_release_mutex
 220  *
 221  * PARAMETERS:  *obj_desc           - The object descriptor for this op
 222  *
 223  * RETURN:      Status
 224  *
 225  * DESCRIPTION: Release a previously acquired Mutex.
 226  *
 227  ******************************************************************************/
 228
 229 acpi_status
 230 acpi_ex_release_mutex (
 231         union acpi_operand_object       *obj_desc,
 232         struct acpi_walk_state          *walk_state)
 233 {
 234         acpi_status                     status;
 235
 236
 237         ACPI_FUNCTION_TRACE ("ex_release_mutex");
 238
 239
 240         if (!obj_desc) {
 241                 return_ACPI_STATUS (AE_BAD_PARAMETER);
 242         }
 243
 244         /* The mutex must have been previously acquired in order to release it */
 245
 246         if (!obj_desc->mutex.owner_thread) {
 247                 ACPI_REPORT_ERROR (("Cannot release Mutex [%4.4s], not acquired\n",
 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_REPORT_ERROR (("Cannot release Mutex [%4.4s], null thread info\n",
 256                                 acpi_ut_get_node_name (obj_desc->mutex.node)));
 257                 return_ACPI_STATUS (AE_AML_INTERNAL);
 258         }
 259
 260         /*
 261          * The Mutex is owned, but this thread must be the owner.
 262          * Special case for Global Lock, any thread can release
 263          */
 264         if ((obj_desc->mutex.owner_thread->thread_id != walk_state->thread->thread_id) &&
 265                 (obj_desc->mutex.semaphore != acpi_gbl_global_lock_semaphore)) {
 266                 ACPI_REPORT_ERROR ((
 267                         "Thread %X cannot release Mutex [%4.4s] acquired by thread %X\n",
 268                         walk_state->thread->thread_id,
 269                         acpi_ut_get_node_name (obj_desc->mutex.node),
 270                         obj_desc->mutex.owner_thread->thread_id));
 271                 return_ACPI_STATUS (AE_AML_NOT_OWNER);
 272         }
 273
 274         /*
 275          * The sync level of the mutex must be less than or
 276          * equal to the current sync level
 277          */
 278         if (obj_desc->mutex.sync_level > walk_state->thread->current_sync_level) {
 279                 ACPI_REPORT_ERROR (("Cannot release Mutex [%4.4s], incorrect sync_level\n",
 280                                 acpi_ut_get_node_name (obj_desc->mutex.node)));
 281                 return_ACPI_STATUS (AE_AML_MUTEX_ORDER);
 282         }
 283
 284         /*
 285          * Match multiple Acquires with multiple Releases
 286          */
 287         obj_desc->mutex.acquisition_depth--;
 288         if (obj_desc->mutex.acquisition_depth != 0) {
 289                 /* Just decrement the depth and return */
 290
 291                 return_ACPI_STATUS (AE_OK);
 292         }
 293
 294         /* Unlink the mutex from the owner's list */
 295
 296         acpi_ex_unlink_mutex (obj_desc);
 297
 298         /* Release the mutex */
 299
 300         status = acpi_ex_system_release_mutex (obj_desc);
 301
 302         /* Update the mutex and walk state */
 303
 304         obj_desc->mutex.owner_thread = NULL;
 305         walk_state->thread->current_sync_level = obj_desc->mutex.sync_level;
 306
 307         return_ACPI_STATUS (status);
 308 }
 309
 310
 311 /*******************************************************************************
 312  *
 313  * FUNCTION:    acpi_ex_release_all_mutexes
 314  *
 315  * PARAMETERS:  *mutex_list           - Head of the mutex list
 316  *
 317  * RETURN:      Status
 318  *
 319  * DESCRIPTION: Release all mutexes in the list
 320  *
 321  ******************************************************************************/
 322
 323 void
 324 acpi_ex_release_all_mutexes (
 325         struct acpi_thread_state        *thread)
 326 {
 327         union acpi_operand_object       *next = thread->acquired_mutex_list;
 328         union acpi_operand_object       *this;
 329         acpi_status                     status;
 330
 331
 332         ACPI_FUNCTION_ENTRY ();
 333
 334
 335         /*
 336          * Traverse the list of owned mutexes, releasing each one.
 337          */
 338         while (next) {
 339                 this = next;
 340                 next = this->mutex.next;
 341
 342                 this->mutex.acquisition_depth = 1;
 343                 this->mutex.prev             = NULL;
 344                 this->mutex.next             = NULL;
 345
 346                  /* Release the mutex */
 347
 348                 status = acpi_ex_system_release_mutex (this);
 349                 if (ACPI_FAILURE (status)) {
 350                         continue;
 351                 }
 352
 353                 /* Mark mutex unowned */
 354
 355                 this->mutex.owner_thread     = NULL;
 356         }
 357 }
 358
 359