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 #include <acpi/acpi.h>
  46 #include <acpi/acinterp.h>
  47
  48 #define _COMPONENT          ACPI_EXECUTER
  49 ACPI_MODULE_NAME("exmutex")
  50
  51 /* Local prototypes */
  52 static void
  53 acpi_ex_link_mutex(union acpi_operand_object *obj_desc,
  54                    struct acpi_thread_state *thread);
  55
  56 /*******************************************************************************
  57  *
  58  * FUNCTION:    acpi_ex_unlink_mutex
  59  *
  60  * PARAMETERS:  obj_desc            - The mutex to be unlinked
  61  *
  62  * RETURN:      None
  63  *
  64  * DESCRIPTION: Remove a mutex from the "acquired_mutex" list
  65  *
  66  ******************************************************************************/
  67
  68 void acpi_ex_unlink_mutex(union acpi_operand_object *obj_desc)
  69 {
  70         struct acpi_thread_state *thread = obj_desc->mutex.owner_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 "acquired_mutex" 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_REPORT_ERROR(("Cannot acquire Mutex [%4.4s], null thread info\n", acpi_ut_get_node_name(obj_desc->mutex.node)));
 157                 return_ACPI_STATUS(AE_AML_INTERNAL);
 158         }
 159
 160         /*
 161          * Current Sync must be less than or equal to the sync level of the
 162          * mutex.  This mechanism provides some deadlock prevention
 163          */
 164         if (walk_state->thread->current_sync_level > obj_desc->mutex.sync_level) {
 165                 ACPI_REPORT_ERROR(("Cannot acquire Mutex [%4.4s], incorrect sync_level\n", acpi_ut_get_node_name(obj_desc->mutex.node)));
 166                 return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
 167         }
 168
 169         /* Support for multiple acquires by the owning thread */
 170
 171         if (obj_desc->mutex.owner_thread) {
 172                 /* Special case for Global Lock, allow all threads */
 173
 174                 if ((obj_desc->mutex.owner_thread->thread_id ==
 175                      walk_state->thread->thread_id) ||
 176                     (obj_desc->mutex.semaphore ==
 177                      acpi_gbl_global_lock_semaphore)) {
 178                         /*
 179                          * The mutex is already owned by this thread,
 180                          * just increment the acquisition depth
 181                          */
 182                         obj_desc->mutex.acquisition_depth++;
 183                         return_ACPI_STATUS(AE_OK);
 184                 }
 185         }
 186
 187         /* Acquire the mutex, wait if necessary */
 188
 189         status = acpi_ex_system_acquire_mutex(time_desc, obj_desc);
 190         if (ACPI_FAILURE(status)) {
 191                 /* Includes failure from a timeout on time_desc */
 192
 193                 return_ACPI_STATUS(status);
 194         }
 195
 196         /* Have the mutex: update mutex and walk info and save the sync_level */
 197
 198         obj_desc->mutex.owner_thread = walk_state->thread;
 199         obj_desc->mutex.acquisition_depth = 1;
 200         obj_desc->mutex.original_sync_level =
 201             walk_state->thread->current_sync_level;
 202
 203         walk_state->thread->current_sync_level = obj_desc->mutex.sync_level;
 204
 205         /* Link the mutex to the current thread for force-unlock at method exit */
 206
 207         acpi_ex_link_mutex(obj_desc, walk_state->thread);
 208
 209         return_ACPI_STATUS(AE_OK);
 210 }
 211
 212 /*******************************************************************************
 213  *
 214  * FUNCTION:    acpi_ex_release_mutex
 215  *
 216  * PARAMETERS:  obj_desc            - The object descriptor for this op
 217  *              walk_state          - Current method execution state
 218  *
 219  * RETURN:      Status
 220  *
 221  * DESCRIPTION: Release a previously acquired Mutex.
 222  *
 223  ******************************************************************************/
 224
 225 acpi_status
 226 acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
 227                       struct acpi_walk_state *walk_state)
 228 {
 229         acpi_status status;
 230
 231         ACPI_FUNCTION_TRACE("ex_release_mutex");
 232
 233         if (!obj_desc) {
 234                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 235         }
 236
 237         /* The mutex must have been previously acquired in order to release it */
 238
 239         if (!obj_desc->mutex.owner_thread) {
 240                 ACPI_REPORT_ERROR(("Cannot release Mutex [%4.4s], not acquired\n", acpi_ut_get_node_name(obj_desc->mutex.node)));
 241                 return_ACPI_STATUS(AE_AML_MUTEX_NOT_ACQUIRED);
 242         }
 243
 244         /* Sanity check -- we must have a valid thread ID */
 245
 246         if (!walk_state->thread) {
 247                 ACPI_REPORT_ERROR(("Cannot release Mutex [%4.4s], null thread info\n", acpi_ut_get_node_name(obj_desc->mutex.node)));
 248                 return_ACPI_STATUS(AE_AML_INTERNAL);
 249         }
 250
 251         /*
 252          * The Mutex is owned, but this thread must be the owner.
 253          * Special case for Global Lock, any thread can release
 254          */
 255         if ((obj_desc->mutex.owner_thread->thread_id !=
 256              walk_state->thread->thread_id)
 257             && (obj_desc->mutex.semaphore != acpi_gbl_global_lock_semaphore)) {
 258                 ACPI_REPORT_ERROR(("Thread %X cannot release Mutex [%4.4s] acquired by thread %X\n", walk_state->thread->thread_id, acpi_ut_get_node_name(obj_desc->mutex.node), obj_desc->mutex.owner_thread->thread_id));
 259                 return_ACPI_STATUS(AE_AML_NOT_OWNER);
 260         }
 261
 262         /*
 263          * The sync level of the mutex must be less than or
 264          * equal to the current sync level
 265          */
 266         if (obj_desc->mutex.sync_level > walk_state->thread->current_sync_level) {
 267                 ACPI_REPORT_ERROR(("Cannot release Mutex [%4.4s], incorrect sync_level\n", acpi_ut_get_node_name(obj_desc->mutex.node)));
 268                 return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
 269         }
 270
 271         /* Match multiple Acquires with multiple Releases */
 272
 273         obj_desc->mutex.acquisition_depth--;
 274         if (obj_desc->mutex.acquisition_depth != 0) {
 275                 /* Just decrement the depth and return */
 276
 277                 return_ACPI_STATUS(AE_OK);
 278         }
 279
 280         /* Unlink the mutex from the owner's list */
 281
 282         acpi_ex_unlink_mutex(obj_desc);
 283
 284         /* Release the mutex */
 285
 286         status = acpi_ex_system_release_mutex(obj_desc);
 287
 288         /* Update the mutex and walk state, restore sync_level before acquire */
 289
 290         obj_desc->mutex.owner_thread = NULL;
 291         walk_state->thread->current_sync_level =
 292             obj_desc->mutex.original_sync_level;
 293
 294         return_ACPI_STATUS(status);
 295 }
 296
 297 /*******************************************************************************
 298  *
 299  * FUNCTION:    acpi_ex_release_all_mutexes
 300  *
 301  * PARAMETERS:  Thread          - Current executing thread object
 302  *
 303  * RETURN:      Status
 304  *
 305  * DESCRIPTION: Release all mutexes held by this thread
 306  *
 307  ******************************************************************************/
 308
 309 void acpi_ex_release_all_mutexes(struct acpi_thread_state *thread)
 310 {
 311         union acpi_operand_object *next = thread->acquired_mutex_list;
 312         union acpi_operand_object *this;
 313         acpi_status status;
 314
 315         ACPI_FUNCTION_ENTRY();
 316
 317         /* Traverse the list of owned mutexes, releasing each one */
 318
 319         while (next) {
 320                 this = next;
 321                 next = this->mutex.next;
 322
 323                 this->mutex.acquisition_depth = 1;
 324                 this->mutex.prev = NULL;
 325                 this->mutex.next = NULL;
 326
 327                 /* Release the mutex */
 328
 329                 status = acpi_ex_system_release_mutex(this);
 330                 if (ACPI_FAILURE(status)) {
 331                         continue;
 332                 }
 333
 334                 /* Mark mutex unowned */
 335
 336                 this->mutex.owner_thread = NULL;
 337
 338                 /* Update Thread sync_level (Last mutex is the important one) */
 339
 340                 thread->current_sync_level = this->mutex.original_sync_level;
 341         }
 342 }