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   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         acpi_owner_id                   owner_id;
  81         struct acpi_walk_state          *walk_state;
  82
  83
  84         ACPI_FUNCTION_TRACE_PTR ("ds_parse_method", obj_handle);
  85
  86
  87         /* Parameter Validation */
  88
  89         if (!obj_handle) {
  90                 return_ACPI_STATUS (AE_NULL_ENTRY);
  91         }
  92
  93         ACPI_DEBUG_PRINT ((ACPI_DB_PARSE, "**** Parsing [%4.4s] **** named_obj=%p\n",
  94                 acpi_ut_get_node_name (obj_handle), obj_handle));
  95
  96         /* Extract the method object from the method Node */
  97
  98         node = (struct acpi_namespace_node *) obj_handle;
  99         obj_desc = acpi_ns_get_attached_object (node);
 100         if (!obj_desc) {
 101                 return_ACPI_STATUS (AE_NULL_OBJECT);
 102         }
 103
 104         /* Create a mutex for the method if there is a concurrency limit */
 105
 106         if ((obj_desc->method.concurrency != ACPI_INFINITE_CONCURRENCY) &&
 107                 (!obj_desc->method.semaphore)) {
 108                 status = acpi_os_create_semaphore (obj_desc->method.concurrency,
 109                                    obj_desc->method.concurrency,
 110                                    &obj_desc->method.semaphore);
 111                 if (ACPI_FAILURE (status)) {
 112                         return_ACPI_STATUS (status);
 113                 }
 114         }
 115
 116         /*
 117          * Allocate a new parser op to be the root of the parsed
 118          * method tree
 119          */
 120         op = acpi_ps_alloc_op (AML_METHOD_OP);
 121         if (!op) {
 122                 return_ACPI_STATUS (AE_NO_MEMORY);
 123         }
 124
 125         /* Init new op with the method name and pointer back to the Node */
 126
 127         acpi_ps_set_name (op, node->name.integer);
 128         op->common.node = node;
 129
 130         /*
 131          * Get a new owner_id for objects created by this method. Namespace
 132          * objects (such as Operation Regions) can be created during the
 133          * first pass parse.
 134          */
 135         owner_id = acpi_ut_allocate_owner_id (ACPI_OWNER_TYPE_METHOD);
 136         obj_desc->method.owning_id = owner_id;
 137
 138         /* Create and initialize a new walk state */
 139
 140         walk_state = acpi_ds_create_walk_state (owner_id, NULL, NULL, NULL);
 141         if (!walk_state) {
 142                 return_ACPI_STATUS (AE_NO_MEMORY);
 143         }
 144
 145         status = acpi_ds_init_aml_walk (walk_state, op, node,
 146                           obj_desc->method.aml_start,
 147                           obj_desc->method.aml_length, NULL, 1);
 148         if (ACPI_FAILURE (status)) {
 149                 acpi_ds_delete_walk_state (walk_state);
 150                 return_ACPI_STATUS (status);
 151         }
 152
 153         /*
 154          * Parse the method, first pass
 155          *
 156          * The first pass load is where newly declared named objects are
 157          * added into the namespace.  Actual evaluation of
 158          * the named objects (what would be called a "second
 159          * pass") happens during the actual execution of the
 160          * method so that operands to the named objects can
 161          * take on dynamic run-time values.
 162          */
 163         status = acpi_ps_parse_aml (walk_state);
 164         if (ACPI_FAILURE (status)) {
 165                 return_ACPI_STATUS (status);
 166         }
 167
 168         ACPI_DEBUG_PRINT ((ACPI_DB_PARSE,
 169                 "**** [%4.4s] Parsed **** named_obj=%p Op=%p\n",
 170                 acpi_ut_get_node_name (obj_handle), obj_handle, op));
 171
 172         acpi_ps_delete_parse_tree (op);
 173         return_ACPI_STATUS (status);
 174 }
 175
 176
 177 /*******************************************************************************
 178  *
 179  * FUNCTION:    acpi_ds_begin_method_execution
 180  *
 181  * PARAMETERS:  method_node         - Node of the method
 182  *              obj_desc            - The method object
 183  *              calling_method_node - Caller of this method (if non-null)
 184  *
 185  * RETURN:      Status
 186  *
 187  * DESCRIPTION: Prepare a method for execution.  Parses the method if necessary,
 188  *              increments the thread count, and waits at the method semaphore
 189  *              for clearance to execute.
 190  *
 191  ******************************************************************************/
 192
 193 acpi_status
 194 acpi_ds_begin_method_execution (
 195         struct acpi_namespace_node      *method_node,
 196         union acpi_operand_object       *obj_desc,
 197         struct acpi_namespace_node      *calling_method_node)
 198 {
 199         acpi_status                     status = AE_OK;
 200
 201
 202         ACPI_FUNCTION_TRACE_PTR ("ds_begin_method_execution", method_node);
 203
 204
 205         if (!method_node) {
 206                 return_ACPI_STATUS (AE_NULL_ENTRY);
 207         }
 208
 209         /*
 210          * If there is a concurrency limit on this method, we need to
 211          * obtain a unit from the method semaphore.
 212          */
 213         if (obj_desc->method.semaphore) {
 214                 /*
 215                  * Allow recursive method calls, up to the reentrancy/concurrency
 216                  * limit imposed by the SERIALIZED rule and the sync_level method
 217                  * parameter.
 218                  *
 219                  * The point of this code is to avoid permanently blocking a
 220                  * thread that is making recursive method calls.
 221                  */
 222                 if (method_node == calling_method_node) {
 223                         if (obj_desc->method.thread_count >= obj_desc->method.concurrency) {
 224                                 return_ACPI_STATUS (AE_AML_METHOD_LIMIT);
 225                         }
 226                 }
 227
 228                 /*
 229                  * Get a unit from the method semaphore. This releases the
 230                  * interpreter if we block
 231                  */
 232                 status = acpi_ex_system_wait_semaphore (obj_desc->method.semaphore,
 233                                  ACPI_WAIT_FOREVER);
 234         }
 235
 236         /*
 237          * Increment the method parse tree thread count since it has been
 238          * reentered one more time (even if it is the same thread)
 239          */
 240         obj_desc->method.thread_count++;
 241         return_ACPI_STATUS (status);
 242 }
 243
 244
 245 /*******************************************************************************
 246  *
 247  * FUNCTION:    acpi_ds_call_control_method
 248  *
 249  * PARAMETERS:  Thread              - Info for this thread
 250  *              this_walk_state     - Current walk state
 251  *              Op                  - Current Op to be walked
 252  *
 253  * RETURN:      Status
 254  *
 255  * DESCRIPTION: Transfer execution to a called control method
 256  *
 257  ******************************************************************************/
 258
 259 acpi_status
 260 acpi_ds_call_control_method (
 261         struct acpi_thread_state        *thread,
 262         struct acpi_walk_state          *this_walk_state,
 263         union acpi_parse_object         *op)
 264 {
 265         acpi_status                     status;
 266         struct acpi_namespace_node      *method_node;
 267         struct acpi_walk_state          *next_walk_state;
 268         union acpi_operand_object       *obj_desc;
 269         struct acpi_parameter_info      info;
 270         u32                             i;
 271
 272
 273         ACPI_FUNCTION_TRACE_PTR ("ds_call_control_method", this_walk_state);
 274
 275         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "Execute method %p, currentstate=%p\n",
 276                 this_walk_state->prev_op, this_walk_state));
 277
 278         /*
 279          * Get the namespace entry for the control method we are about to call
 280          */
 281         method_node = this_walk_state->method_call_node;
 282         if (!method_node) {
 283                 return_ACPI_STATUS (AE_NULL_ENTRY);
 284         }
 285
 286         obj_desc = acpi_ns_get_attached_object (method_node);
 287         if (!obj_desc) {
 288                 return_ACPI_STATUS (AE_NULL_OBJECT);
 289         }
 290
 291         obj_desc->method.owning_id = acpi_ut_allocate_owner_id (ACPI_OWNER_TYPE_METHOD);
 292
 293         /* Init for new method, wait on concurrency semaphore */
 294
 295         status = acpi_ds_begin_method_execution (method_node, obj_desc,
 296                           this_walk_state->method_node);
 297         if (ACPI_FAILURE (status)) {
 298                 return_ACPI_STATUS (status);
 299         }
 300
 301         if (!(obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY)) {
 302                 /* 1) Parse: Create a new walk state for the preempting walk */
 303
 304                 next_walk_state = acpi_ds_create_walk_state (obj_desc->method.owning_id,
 305                                   op, obj_desc, NULL);
 306                 if (!next_walk_state) {
 307                         return_ACPI_STATUS (AE_NO_MEMORY);
 308                 }
 309
 310                 /* Create and init a Root Node */
 311
 312                 op = acpi_ps_create_scope_op ();
 313                 if (!op) {
 314                         status = AE_NO_MEMORY;
 315                         goto cleanup;
 316                 }
 317
 318                 status = acpi_ds_init_aml_walk (next_walk_state, op, method_node,
 319                                   obj_desc->method.aml_start, obj_desc->method.aml_length,
 320                                   NULL, 1);
 321                 if (ACPI_FAILURE (status)) {
 322                         acpi_ds_delete_walk_state (next_walk_state);
 323                         goto cleanup;
 324                 }
 325
 326                 /* Begin AML parse */
 327
 328                 status = acpi_ps_parse_aml (next_walk_state);
 329                 acpi_ps_delete_parse_tree (op);
 330         }
 331
 332         /* 2) Execute: Create a new state for the preempting walk */
 333
 334         next_walk_state = acpi_ds_create_walk_state (obj_desc->method.owning_id,
 335                           NULL, obj_desc, thread);
 336         if (!next_walk_state) {
 337                 status = AE_NO_MEMORY;
 338                 goto cleanup;
 339         }
 340         /*
 341          * The resolved arguments were put on the previous walk state's operand
 342          * stack.  Operands on the previous walk state stack always
 343          * start at index 0.
 344          * Null terminate the list of arguments
 345          */
 346         this_walk_state->operands [this_walk_state->num_operands] = NULL;
 347
 348         info.parameters = &this_walk_state->operands[0];
 349         info.parameter_type = ACPI_PARAM_ARGS;
 350
 351         status = acpi_ds_init_aml_walk (next_walk_state, NULL, method_node,
 352                           obj_desc->method.aml_start, obj_desc->method.aml_length,
 353                           &info, 3);
 354         if (ACPI_FAILURE (status)) {
 355                 goto cleanup;
 356         }
 357
 358         /*
 359          * Delete the operands on the previous walkstate operand stack
 360          * (they were copied to new objects)
 361          */
 362         for (i = 0; i < obj_desc->method.param_count; i++) {
 363                 acpi_ut_remove_reference (this_walk_state->operands [i]);
 364                 this_walk_state->operands [i] = NULL;
 365         }
 366
 367         /* Clear the operand stack */
 368
 369         this_walk_state->num_operands = 0;
 370
 371         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
 372                 "Starting nested execution, newstate=%p\n", next_walk_state));
 373
 374         if (obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY) {
 375                 status = obj_desc->method.implementation (next_walk_state);
 376                 return_ACPI_STATUS (status);
 377         }
 378
 379         return_ACPI_STATUS (AE_OK);
 380
 381
 382         /* On error, we must delete the new walk state */
 383
 384 cleanup:
 385         if (next_walk_state && (next_walk_state->method_desc)) {
 386                 /* Decrement the thread count on the method parse tree */
 387
 388            next_walk_state->method_desc->method.thread_count--;
 389         }
 390         (void) acpi_ds_terminate_control_method (next_walk_state);
 391         acpi_ds_delete_walk_state (next_walk_state);
 392         return_ACPI_STATUS (status);
 393 }
 394
 395
 396 /*******************************************************************************
 397  *
 398  * FUNCTION:    acpi_ds_restart_control_method
 399  *
 400  * PARAMETERS:  walk_state          - State for preempted method (caller)
 401  *              return_desc         - Return value from the called method
 402  *
 403  * RETURN:      Status
 404  *
 405  * DESCRIPTION: Restart a method that was preempted by another (nested) method
 406  *              invocation.  Handle the return value (if any) from the callee.
 407  *
 408  ******************************************************************************/
 409
 410 acpi_status
 411 acpi_ds_restart_control_method (
 412         struct acpi_walk_state          *walk_state,
 413         union acpi_operand_object       *return_desc)
 414 {
 415         acpi_status                     status;
 416
 417
 418         ACPI_FUNCTION_TRACE_PTR ("ds_restart_control_method", walk_state);
 419
 420
 421         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
 422                 "****Restart [%4.4s] Op %p return_value_from_callee %p\n",
 423                 (char *) &walk_state->method_node->name, walk_state->method_call_op,
 424                 return_desc));
 425
 426         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
 427                 "    return_from_this_method_used?=%X res_stack %p Walk %p\n",
 428                 walk_state->return_used,
 429                 walk_state->results, walk_state));
 430
 431         /* Did the called method return a value? */
 432
 433         if (return_desc) {
 434                 /* Are we actually going to use the return value? */
 435
 436                 if (walk_state->return_used) {
 437                         /* Save the return value from the previous method */
 438
 439                         status = acpi_ds_result_push (return_desc, walk_state);
 440                         if (ACPI_FAILURE (status)) {
 441                                 acpi_ut_remove_reference (return_desc);
 442                                 return_ACPI_STATUS (status);
 443                         }
 444
 445                         /*
 446                          * Save as THIS method's return value in case it is returned
 447                          * immediately to yet another method
 448                          */
 449                         walk_state->return_desc = return_desc;
 450                 }
 451
 452                 /*
 453                  * The following code is the
 454                  * optional support for a so-called "implicit return". Some AML code
 455                  * assumes that the last value of the method is "implicitly" returned
 456                  * to the caller. Just save the last result as the return value.
 457                  * NOTE: this is optional because the ASL language does not actually
 458                  * support this behavior.
 459                  */
 460                 else if (!acpi_ds_do_implicit_return (return_desc, walk_state, FALSE)) {
 461                         /*
 462                          * Delete the return value if it will not be used by the
 463                          * calling method
 464                          */
 465                         acpi_ut_remove_reference (return_desc);
 466                 }
 467         }
 468
 469         return_ACPI_STATUS (AE_OK);
 470 }
 471
 472
 473 /*******************************************************************************
 474  *
 475  * FUNCTION:    acpi_ds_terminate_control_method
 476  *
 477  * PARAMETERS:  walk_state          - State of the method
 478  *
 479  * RETURN:      Status
 480  *
 481  * DESCRIPTION: Terminate a control method.  Delete everything that the method
 482  *              created, delete all locals and arguments, and delete the parse
 483  *              tree if requested.
 484  *
 485  ******************************************************************************/
 486
 487 acpi_status
 488 acpi_ds_terminate_control_method (
 489         struct acpi_walk_state          *walk_state)
 490 {
 491         union acpi_operand_object       *obj_desc;
 492         struct acpi_namespace_node      *method_node;
 493         acpi_status                     status;
 494
 495
 496         ACPI_FUNCTION_TRACE_PTR ("ds_terminate_control_method", walk_state);
 497
 498
 499         if (!walk_state) {
 500                 return (AE_BAD_PARAMETER);
 501         }
 502
 503         /* The current method object was saved in the walk state */
 504
 505         obj_desc = walk_state->method_desc;
 506         if (!obj_desc) {
 507                 return_ACPI_STATUS (AE_OK);
 508         }
 509
 510         /* Delete all arguments and locals */
 511
 512         acpi_ds_method_data_delete_all (walk_state);
 513
 514         /*
 515          * Lock the parser while we terminate this method.
 516          * If this is the last thread executing the method,
 517          * we have additional cleanup to perform
 518          */
 519         status = acpi_ut_acquire_mutex (ACPI_MTX_PARSER);
 520         if (ACPI_FAILURE (status)) {
 521                 return_ACPI_STATUS (status);
 522         }
 523
 524         /* Signal completion of the execution of this method if necessary */
 525
 526         if (walk_state->method_desc->method.semaphore) {
 527                 status = acpi_os_signal_semaphore (
 528                                   walk_state->method_desc->method.semaphore, 1);
 529                 if (ACPI_FAILURE (status)) {
 530                         ACPI_REPORT_ERROR (("Could not signal method semaphore\n"));
 531                         status = AE_OK;
 532
 533                         /* Ignore error and continue cleanup */
 534                 }
 535         }
 536
 537         if (walk_state->method_desc->method.thread_count) {
 538                 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
 539                         "*** Not deleting method namespace, there are still %d threads\n",
 540                         walk_state->method_desc->method.thread_count));
 541         }
 542
 543         if (!walk_state->method_desc->method.thread_count) {
 544                 /*
 545                  * Support to dynamically change a method from not_serialized to
 546                  * Serialized if it appears that the method is written foolishly and
 547                  * does not support multiple thread execution.  The best example of this
 548                  * is if such a method creates namespace objects and blocks.  A second
 549                  * thread will fail with an AE_ALREADY_EXISTS exception
 550                  *
 551                  * This code is here because we must wait until the last thread exits
 552                  * before creating the synchronization semaphore.
 553                  */
 554                 if ((walk_state->method_desc->method.concurrency == 1) &&
 555                         (!walk_state->method_desc->method.semaphore)) {
 556                         status = acpi_os_create_semaphore (1,
 557                                          1,
 558                                          &walk_state->method_desc->method.semaphore);
 559                 }
 560
 561                 /*
 562                  * There are no more threads executing this method.  Perform
 563                  * additional cleanup.
 564                  *
 565                  * The method Node is stored in the walk state
 566                  */
 567                 method_node = walk_state->method_node;
 568
 569                 /*
 570                  * Delete any namespace entries created immediately underneath
 571                  * the method
 572                  */
 573                 status = acpi_ut_acquire_mutex (ACPI_MTX_NAMESPACE);
 574                 if (ACPI_FAILURE (status)) {
 575                         return_ACPI_STATUS (status);
 576                 }
 577
 578                 if (method_node->child) {
 579                         acpi_ns_delete_namespace_subtree (method_node);
 580                 }
 581
 582                 /*
 583                  * Delete any namespace entries created anywhere else within
 584                  * the namespace
 585                  */
 586                 acpi_ns_delete_namespace_by_owner (walk_state->method_desc->method.owning_id);
 587                 status = acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);
 588                 if (ACPI_FAILURE (status)) {
 589                         return_ACPI_STATUS (status);
 590                 }
 591         }
 592
 593         status = acpi_ut_release_mutex (ACPI_MTX_PARSER);
 594         return_ACPI_STATUS (status);
 595 }
 596
 597