err.no Git - linux-2.6/blob - drivers/acpi/dispatcher/dsmethod.c

   1 /******************************************************************************
   2  *
   3  * Module Name: dsmethod - Parser/Interpreter interface - control method parsing
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2005, R. Byron Moore
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions, and the following disclaimer,
  16  *    without modification.
  17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  18  *    substantially similar to the "NO WARRANTY" disclaimer below
  19  *    ("Disclaimer") and any redistribution must be conditioned upon
  20  *    including a substantially similar Disclaimer requirement for further
  21  *    binary redistribution.
  22  * 3. Neither the names of the above-listed copyright holders nor the names
  23  *    of any contributors may be used to endorse or promote products derived
  24  *    from this software without specific prior written permission.
  25  *
  26  * Alternatively, this software may be distributed under the terms of the
  27  * GNU General Public License ("GPL") version 2 as published by the Free
  28  * Software Foundation.
  29  *
  30  * NO WARRANTY
  31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  41  * POSSIBILITY OF SUCH DAMAGES.
  42  */
  43
  44
  45 #include <acpi/acpi.h>
  46 #include <acpi/acparser.h>
  47 #include <acpi/amlcode.h>
  48 #include <acpi/acdispat.h>
  49 #include <acpi/acinterp.h>
  50 #include <acpi/acnamesp.h>
  51
  52
  53 #define _COMPONENT          ACPI_DISPATCHER
  54          ACPI_MODULE_NAME    ("dsmethod")
  55
  56
  57 /*******************************************************************************
  58  *
  59  * FUNCTION:    acpi_ds_parse_method
  60  *
  61  * PARAMETERS:  obj_handle      - Method node
  62  *
  63  * RETURN:      Status
  64  *
  65  * DESCRIPTION: Call the parser and parse the AML that is associated with the
  66  *              method.
  67  *
  68  * MUTEX:       Assumes parser is locked
  69  *
  70  ******************************************************************************/
  71
  72 acpi_status
  73 acpi_ds_parse_method (
  74         acpi_handle                     obj_handle)
  75 {
  76         acpi_status                     status;
  77         union acpi_operand_object       *obj_desc;
  78         union acpi_parse_object         *op;
  79         struct acpi_namespace_node      *node;
  80         struct acpi_walk_state          *walk_state;
  81
  82
  83         ACPI_FUNCTION_TRACE_PTR ("ds_parse_method", obj_handle);
  84
  85
  86         /* Parameter Validation */
  87
  88         if (!obj_handle) {
  89                 return_ACPI_STATUS (AE_NULL_ENTRY);
  90         }
  91
  92         ACPI_DEBUG_PRINT ((ACPI_DB_PARSE, "**** Parsing [%4.4s] **** named_obj=%p\n",
  93                 acpi_ut_get_node_name (obj_handle), obj_handle));
  94
  95         /* Extract the method object from the method Node */
  96
  97         node = (struct acpi_namespace_node *) obj_handle;
  98         obj_desc = acpi_ns_get_attached_object (node);
  99         if (!obj_desc) {
 100                 return_ACPI_STATUS (AE_NULL_OBJECT);
 101         }
 102
 103         /* Create a mutex for the method if there is a concurrency limit */
 104
 105         if ((obj_desc->method.concurrency != ACPI_INFINITE_CONCURRENCY) &&
 106                 (!obj_desc->method.semaphore)) {
 107                 status = acpi_os_create_semaphore (obj_desc->method.concurrency,
 108                                    obj_desc->method.concurrency,
 109                                    &obj_desc->method.semaphore);
 110                 if (ACPI_FAILURE (status)) {
 111                         return_ACPI_STATUS (status);
 112                 }
 113         }
 114
 115         /*
 116          * Allocate a new parser op to be the root of the parsed
 117          * method tree
 118          */
 119         op = acpi_ps_alloc_op (AML_METHOD_OP);
 120         if (!op) {
 121                 return_ACPI_STATUS (AE_NO_MEMORY);
 122         }
 123
 124         /* Init new op with the method name and pointer back to the Node */
 125
 126         acpi_ps_set_name (op, node->name.integer);
 127         op->common.node = node;
 128
 129         /*
 130          * Get a new owner_id for objects created by this method. Namespace
 131          * objects (such as Operation Regions) can be created during the
 132          * first pass parse.
 133          */
 134         status = acpi_ut_allocate_owner_id (&obj_desc->method.owner_id);
 135         if (ACPI_FAILURE (status)) {
 136                 goto cleanup;
 137         }
 138
 139         /* Create and initialize a new walk state */
 140
 141         walk_state = acpi_ds_create_walk_state (
 142                           obj_desc->method.owner_id, NULL, NULL, NULL);
 143         if (!walk_state) {
 144                 status = AE_NO_MEMORY;
 145                 goto cleanup2;
 146         }
 147
 148         status = acpi_ds_init_aml_walk (walk_state, op, node,
 149                           obj_desc->method.aml_start,
 150                           obj_desc->method.aml_length, NULL, 1);
 151         if (ACPI_FAILURE (status)) {
 152                 acpi_ds_delete_walk_state (walk_state);
 153                 goto cleanup2;
 154         }
 155
 156         /*
 157          * Parse the method, first pass
 158          *
 159          * The first pass load is where newly declared named objects are added into
 160          * the namespace.  Actual evaluation of the named objects (what would be
 161          * called a "second pass") happens during the actual execution of the
 162          * method so that operands to the named objects can take on dynamic
 163          * run-time values.
 164          */
 165         status = acpi_ps_parse_aml (walk_state);
 166         if (ACPI_FAILURE (status)) {
 167                 goto cleanup2;
 168         }
 169
 170         ACPI_DEBUG_PRINT ((ACPI_DB_PARSE,
 171                 "**** [%4.4s] Parsed **** named_obj=%p Op=%p\n",
 172                 acpi_ut_get_node_name (obj_handle), obj_handle, op));
 173
 174 cleanup2:
 175         (void) acpi_ut_release_owner_id (obj_desc->method.owner_id);
 176
 177 cleanup:
 178         acpi_ps_delete_parse_tree (op);
 179         return_ACPI_STATUS (status);
 180 }
 181
 182
 183 /*******************************************************************************
 184  *
 185  * FUNCTION:    acpi_ds_begin_method_execution
 186  *
 187  * PARAMETERS:  method_node         - Node of the method
 188  *              obj_desc            - The method object
 189  *              calling_method_node - Caller of this method (if non-null)
 190  *
 191  * RETURN:      Status
 192  *
 193  * DESCRIPTION: Prepare a method for execution.  Parses the method if necessary,
 194  *              increments the thread count, and waits at the method semaphore
 195  *              for clearance to execute.
 196  *
 197  ******************************************************************************/
 198
 199 acpi_status
 200 acpi_ds_begin_method_execution (
 201         struct acpi_namespace_node      *method_node,
 202         union acpi_operand_object       *obj_desc,
 203         struct acpi_namespace_node      *calling_method_node)
 204 {
 205         acpi_status                     status = AE_OK;
 206
 207
 208         ACPI_FUNCTION_TRACE_PTR ("ds_begin_method_execution", method_node);
 209
 210
 211         if (!method_node) {
 212                 return_ACPI_STATUS (AE_NULL_ENTRY);
 213         }
 214
 215         /*
 216          * If there is a concurrency limit on this method, we need to
 217          * obtain a unit from the method semaphore.
 218          */
 219         if (obj_desc->method.semaphore) {
 220                 /*
 221                  * Allow recursive method calls, up to the reentrancy/concurrency
 222                  * limit imposed by the SERIALIZED rule and the sync_level method
 223                  * parameter.
 224                  *
 225                  * The point of this code is to avoid permanently blocking a
 226                  * thread that is making recursive method calls.
 227                  */
 228                 if (method_node == calling_method_node) {
 229                         if (obj_desc->method.thread_count >= obj_desc->method.concurrency) {
 230                                 return_ACPI_STATUS (AE_AML_METHOD_LIMIT);
 231                         }
 232                 }
 233
 234                 /*
 235                  * Get a unit from the method semaphore. This releases the
 236                  * interpreter if we block
 237                  */
 238                 status = acpi_ex_system_wait_semaphore (obj_desc->method.semaphore,
 239                                  ACPI_WAIT_FOREVER);
 240         }
 241
 242         /*
 243          * Increment the method parse tree thread count since it has been
 244          * reentered one more time (even if it is the same thread)
 245          */
 246         obj_desc->method.thread_count++;
 247         return_ACPI_STATUS (status);
 248 }
 249
 250
 251 /*******************************************************************************
 252  *
 253  * FUNCTION:    acpi_ds_call_control_method
 254  *
 255  * PARAMETERS:  Thread              - Info for this thread
 256  *              this_walk_state     - Current walk state
 257  *              Op                  - Current Op to be walked
 258  *
 259  * RETURN:      Status
 260  *
 261  * DESCRIPTION: Transfer execution to a called control method
 262  *
 263  ******************************************************************************/
 264
 265 acpi_status
 266 acpi_ds_call_control_method (
 267         struct acpi_thread_state        *thread,
 268         struct acpi_walk_state          *this_walk_state,
 269         union acpi_parse_object         *op)
 270 {
 271         acpi_status                     status;
 272         struct acpi_namespace_node      *method_node;
 273         struct acpi_walk_state          *next_walk_state = NULL;
 274         union acpi_operand_object       *obj_desc;
 275         struct acpi_parameter_info      info;
 276         u32                             i;
 277
 278
 279         ACPI_FUNCTION_TRACE_PTR ("ds_call_control_method", this_walk_state);
 280
 281         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "Execute method %p, currentstate=%p\n",
 282                 this_walk_state->prev_op, this_walk_state));
 283
 284         /*
 285          * Get the namespace entry for the control method we are about to call
 286          */
 287         method_node = this_walk_state->method_call_node;
 288         if (!method_node) {
 289                 return_ACPI_STATUS (AE_NULL_ENTRY);
 290         }
 291
 292         obj_desc = acpi_ns_get_attached_object (method_node);
 293         if (!obj_desc) {
 294                 return_ACPI_STATUS (AE_NULL_OBJECT);
 295         }
 296
 297         status = acpi_ut_allocate_owner_id (&obj_desc->method.owner_id);
 298         if (ACPI_FAILURE (status)) {
 299                 return_ACPI_STATUS (status);
 300         }
 301
 302         /* Init for new method, wait on concurrency semaphore */
 303
 304         status = acpi_ds_begin_method_execution (method_node, obj_desc,
 305                           this_walk_state->method_node);
 306         if (ACPI_FAILURE (status)) {
 307                 goto cleanup;
 308         }
 309
 310         if (!(obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY)) {
 311                 /* 1) Parse: Create a new walk state for the preempting walk */
 312
 313                 next_walk_state = acpi_ds_create_walk_state (obj_desc->method.owner_id,
 314                                   op, obj_desc, NULL);
 315                 if (!next_walk_state) {
 316                         return_ACPI_STATUS (AE_NO_MEMORY);
 317                 }
 318
 319                 /* Create and init a Root Node */
 320
 321                 op = acpi_ps_create_scope_op ();
 322                 if (!op) {
 323                         status = AE_NO_MEMORY;
 324                         goto cleanup;
 325                 }
 326
 327                 status = acpi_ds_init_aml_walk (next_walk_state, op, method_node,
 328                                   obj_desc->method.aml_start, obj_desc->method.aml_length,
 329                                   NULL, 1);
 330                 if (ACPI_FAILURE (status)) {
 331                         acpi_ds_delete_walk_state (next_walk_state);
 332                         goto cleanup;
 333                 }
 334
 335                 /* Begin AML parse */
 336
 337                 status = acpi_ps_parse_aml (next_walk_state);
 338                 acpi_ps_delete_parse_tree (op);
 339         }
 340
 341         /* 2) Execute: Create a new state for the preempting walk */
 342
 343         next_walk_state = acpi_ds_create_walk_state (obj_desc->method.owner_id,
 344                           NULL, obj_desc, thread);
 345         if (!next_walk_state) {
 346                 status = AE_NO_MEMORY;
 347                 goto cleanup;
 348         }
 349         /*
 350          * The resolved arguments were put on the previous walk state's operand
 351          * stack.  Operands on the previous walk state stack always
 352          * start at index 0.
 353          * Null terminate the list of arguments
 354          */
 355         this_walk_state->operands [this_walk_state->num_operands] = NULL;
 356
 357         info.parameters = &this_walk_state->operands[0];
 358         info.parameter_type = ACPI_PARAM_ARGS;
 359
 360         status = acpi_ds_init_aml_walk (next_walk_state, NULL, method_node,
 361                           obj_desc->method.aml_start, obj_desc->method.aml_length,
 362                           &info, 3);
 363         if (ACPI_FAILURE (status)) {
 364                 goto cleanup;
 365         }
 366
 367         /*
 368          * Delete the operands on the previous walkstate operand stack
 369          * (they were copied to new objects)
 370          */
 371         for (i = 0; i < obj_desc->method.param_count; i++) {
 372                 acpi_ut_remove_reference (this_walk_state->operands [i]);
 373                 this_walk_state->operands [i] = NULL;
 374         }
 375
 376         /* Clear the operand stack */
 377
 378         this_walk_state->num_operands = 0;
 379
 380         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
 381                 "Starting nested execution, newstate=%p\n", next_walk_state));
 382
 383         if (obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY) {
 384                 status = obj_desc->method.implementation (next_walk_state);
 385                 return_ACPI_STATUS (status);
 386         }
 387
 388         return_ACPI_STATUS (AE_OK);
 389
 390
 391         /* On error, we must delete the new walk state */
 392
 393 cleanup:
 394         (void) acpi_ut_release_owner_id (obj_desc->method.owner_id);
 395         if (next_walk_state && (next_walk_state->method_desc)) {
 396                 /* Decrement the thread count on the method parse tree */
 397
 398            next_walk_state->method_desc->method.thread_count--;
 399         }
 400         (void) acpi_ds_terminate_control_method (next_walk_state);
 401         acpi_ds_delete_walk_state (next_walk_state);
 402         return_ACPI_STATUS (status);
 403 }
 404
 405
 406 /*******************************************************************************
 407  *
 408  * FUNCTION:    acpi_ds_restart_control_method
 409  *
 410  * PARAMETERS:  walk_state          - State for preempted method (caller)
 411  *              return_desc         - Return value from the called method
 412  *
 413  * RETURN:      Status
 414  *
 415  * DESCRIPTION: Restart a method that was preempted by another (nested) method
 416  *              invocation.  Handle the return value (if any) from the callee.
 417  *
 418  ******************************************************************************/
 419
 420 acpi_status
 421 acpi_ds_restart_control_method (
 422         struct acpi_walk_state          *walk_state,
 423         union acpi_operand_object       *return_desc)
 424 {
 425         acpi_status                     status;
 426
 427
 428         ACPI_FUNCTION_TRACE_PTR ("ds_restart_control_method", walk_state);
 429
 430
 431         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
 432                 "****Restart [%4.4s] Op %p return_value_from_callee %p\n",
 433                 (char *) &walk_state->method_node->name, walk_state->method_call_op,
 434                 return_desc));
 435
 436         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
 437                 "    return_from_this_method_used?=%X res_stack %p Walk %p\n",
 438                 walk_state->return_used,
 439                 walk_state->results, walk_state));
 440
 441         /* Did the called method return a value? */
 442
 443         if (return_desc) {
 444                 /* Are we actually going to use the return value? */
 445
 446                 if (walk_state->return_used) {
 447                         /* Save the return value from the previous method */
 448
 449                         status = acpi_ds_result_push (return_desc, walk_state);
 450                         if (ACPI_FAILURE (status)) {
 451                                 acpi_ut_remove_reference (return_desc);
 452                                 return_ACPI_STATUS (status);
 453                         }
 454
 455                         /*
 456                          * Save as THIS method's return value in case it is returned
 457                          * immediately to yet another method
 458                          */
 459                         walk_state->return_desc = return_desc;
 460                 }
 461
 462                 /*
 463                  * The following code is the
 464                  * optional support for a so-called "implicit return". Some AML code
 465                  * assumes that the last value of the method is "implicitly" returned
 466                  * to the caller. Just save the last result as the return value.
 467                  * NOTE: this is optional because the ASL language does not actually
 468                  * support this behavior.
 469                  */
 470                 else if (!acpi_ds_do_implicit_return (return_desc, walk_state, FALSE)) {
 471                         /*
 472                          * Delete the return value if it will not be used by the
 473                          * calling method
 474                          */
 475                         acpi_ut_remove_reference (return_desc);
 476                 }
 477         }
 478
 479         return_ACPI_STATUS (AE_OK);
 480 }
 481
 482
 483 /*******************************************************************************
 484  *
 485  * FUNCTION:    acpi_ds_terminate_control_method
 486  *
 487  * PARAMETERS:  walk_state          - State of the method
 488  *
 489  * RETURN:      Status
 490  *
 491  * DESCRIPTION: Terminate a control method.  Delete everything that the method
 492  *              created, delete all locals and arguments, and delete the parse
 493  *              tree if requested.
 494  *
 495  ******************************************************************************/
 496
 497 acpi_status
 498 acpi_ds_terminate_control_method (
 499         struct acpi_walk_state          *walk_state)
 500 {
 501         union acpi_operand_object       *obj_desc;
 502         struct acpi_namespace_node      *method_node;
 503         acpi_status                     status;
 504
 505
 506         ACPI_FUNCTION_TRACE_PTR ("ds_terminate_control_method", walk_state);
 507
 508
 509         if (!walk_state) {
 510                 return (AE_BAD_PARAMETER);
 511         }
 512
 513         /* The current method object was saved in the walk state */
 514
 515         obj_desc = walk_state->method_desc;
 516         if (!obj_desc) {
 517                 return_ACPI_STATUS (AE_OK);
 518         }
 519
 520         /* Delete all arguments and locals */
 521
 522         acpi_ds_method_data_delete_all (walk_state);
 523
 524         /*
 525          * Lock the parser while we terminate this method.
 526          * If this is the last thread executing the method,
 527          * we have additional cleanup to perform
 528          */
 529         status = acpi_ut_acquire_mutex (ACPI_MTX_PARSER);
 530         if (ACPI_FAILURE (status)) {
 531                 return_ACPI_STATUS (status);
 532         }
 533
 534         /* Signal completion of the execution of this method if necessary */
 535
 536         if (walk_state->method_desc->method.semaphore) {
 537                 status = acpi_os_signal_semaphore (
 538                                   walk_state->method_desc->method.semaphore, 1);
 539                 if (ACPI_FAILURE (status)) {
 540                         ACPI_REPORT_ERROR (("Could not signal method semaphore\n"));
 541                         status = AE_OK;
 542
 543                         /* Ignore error and continue cleanup */
 544                 }
 545         }
 546
 547         if (walk_state->method_desc->method.thread_count) {
 548                 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
 549                         "*** Not deleting method namespace, there are still %d threads\n",
 550                         walk_state->method_desc->method.thread_count));
 551         }
 552
 553         if (!walk_state->method_desc->method.thread_count) {
 554                 /*
 555                  * Support to dynamically change a method from not_serialized to
 556                  * Serialized if it appears that the method is written foolishly and
 557                  * does not support multiple thread execution.  The best example of this
 558                  * is if such a method creates namespace objects and blocks.  A second
 559                  * thread will fail with an AE_ALREADY_EXISTS exception
 560                  *
 561                  * This code is here because we must wait until the last thread exits
 562                  * before creating the synchronization semaphore.
 563                  */
 564                 if ((walk_state->method_desc->method.concurrency == 1) &&
 565                         (!walk_state->method_desc->method.semaphore)) {
 566                         status = acpi_os_create_semaphore (1,
 567                                          1,
 568                                          &walk_state->method_desc->method.semaphore);
 569                 }
 570
 571                 /*
 572                  * There are no more threads executing this method.  Perform
 573                  * additional cleanup.
 574                  *
 575                  * The method Node is stored in the walk state
 576                  */
 577                 method_node = walk_state->method_node;
 578
 579                 /*
 580                  * Delete any namespace entries created immediately underneath
 581                  * the method
 582                  */
 583                 status = acpi_ut_acquire_mutex (ACPI_MTX_NAMESPACE);
 584                 if (ACPI_FAILURE (status)) {
 585                         return_ACPI_STATUS (status);
 586                 }
 587
 588                 if (method_node->child) {
 589                         acpi_ns_delete_namespace_subtree (method_node);
 590                 }
 591
 592                 /*
 593                  * Delete any namespace entries created anywhere else within
 594                  * the namespace
 595                  */
 596                 acpi_ns_delete_namespace_by_owner (walk_state->method_desc->method.owner_id);
 597                 status = acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);
 598                 if (ACPI_FAILURE (status)) {
 599                         return_ACPI_STATUS (status);
 600                 }
 601         }
 602
 603         status = acpi_ut_release_mutex (ACPI_MTX_PARSER);
 604         return_ACPI_STATUS (status);
 605 }
 606
 607