LXR 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 - 2006, 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
  49ACPI_MODULE_NAME("exmutex")
  50
  51/* Local prototypes */
  52static void
  53acpi_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 "AcquiredMutex" list
  65 *
  66 ******************************************************************************/
  67
  68void 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 "AcquiredMutex" list for this walk
  99 *
 100 ******************************************************************************/
 101
 102static void
 103acpi_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
 140acpi_status
 141acpi_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) {
 177
 178                /* Special case for Global Lock, allow all threads */
 179
 180                if ((obj_desc->mutex.owner_thread->thread_id ==
 181                     walk_state->thread->thread_id) ||
 182                    (obj_desc->mutex.os_mutex == ACPI_GLOBAL_LOCK)) {
 183                        /*
 184                         * The mutex is already owned by this thread,
 185                         * just increment the acquisition depth
 186                         */
 187                        obj_desc->mutex.acquisition_depth++;
 188                        return_ACPI_STATUS(AE_OK);
 189                }
 190        }
 191
 192        /* Acquire the mutex, wait if necessary */
 193
 194        status = acpi_ex_system_acquire_mutex(time_desc, obj_desc);
 195        if (ACPI_FAILURE(status)) {
 196
 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 and save the sync_level */
 203
 204        obj_desc->mutex.owner_thread = walk_state->thread;
 205        obj_desc->mutex.acquisition_depth = 1;
 206        obj_desc->mutex.original_sync_level =
 207            walk_state->thread->current_sync_level;
 208
 209        walk_state->thread->current_sync_level = obj_desc->mutex.sync_level;
 210
 211        /* Link the mutex to the current thread for force-unlock at method exit */
 212
 213        acpi_ex_link_mutex(obj_desc, walk_state->thread);
 214
 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
 231acpi_status
 232acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
 233                      struct acpi_walk_state *walk_state)
 234{
 235        acpi_status status;
 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) {
 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->thread_id !=
 266             walk_state->thread->thread_id)
 267            && (obj_desc->mutex.os_mutex != ACPI_GLOBAL_LOCK)) {
 268                ACPI_ERROR((AE_INFO,
 269                            "Thread %X cannot release Mutex [%4.4s] acquired by thread %X",
 270                            (u32) walk_state->thread->thread_id,
 271                            acpi_ut_get_node_name(obj_desc->mutex.node),
 272                            (u32) obj_desc->mutex.owner_thread->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
 278         * equal to the current 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);
 300
 301        /* Release the mutex */
 302
 303        status = acpi_ex_system_release_mutex(obj_desc);
 304
 305        /* Update the mutex and walk state, restore sync_level before acquire */
 306
 307        obj_desc->mutex.owner_thread = NULL;
 308        walk_state->thread->current_sync_level =
 309            obj_desc->mutex.original_sync_level;
 310
 311        return_ACPI_STATUS(status);
 312}
 313
 314/*******************************************************************************
 315 *
 316 * FUNCTION:    acpi_ex_release_all_mutexes
 317 *
 318 * PARAMETERS:  Thread          - Current executing thread object
 319 *
 320 * RETURN:      Status
 321 *
 322 * DESCRIPTION: Release all mutexes held by this thread
 323 *
 324 ******************************************************************************/
 325
 326void acpi_ex_release_all_mutexes(struct acpi_thread_state *thread)
 327{
 328        union acpi_operand_object *next = thread->acquired_mutex_list;
 329        union acpi_operand_object *this;
 330        acpi_status status;
 331
 332        ACPI_FUNCTION_ENTRY();
 333
 334        /* Traverse the list of owned mutexes, releasing each one */
 335
 336        while (next) {
 337                this = next;
 338                next = this->mutex.next;
 339
 340                this->mutex.acquisition_depth = 1;
 341                this->mutex.prev = NULL;
 342                this->mutex.next = NULL;
 343
 344                /* Release the mutex */
 345
 346                status = acpi_ex_system_release_mutex(this);
 347                if (ACPI_FAILURE(status)) {
 348                        continue;
 349                }
 350
 351                /* Mark mutex unowned */
 352
 353                this->mutex.owner_thread = NULL;
 354
 355                /* Update Thread sync_level (Last mutex is the important one) */
 356
 357                thread->current_sync_level = this->mutex.original_sync_level;
 358        }
 359}
 360