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         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                 status = AE_NO_MEMORY;
 143                 goto cleanup;
 144         }
 145
 146         status = acpi_ds_init_aml_walk (walk_state, op, node,
 147                           obj_desc->method.aml_start,
 148                           obj_desc->method.aml_length, NULL, 1);
 149         if (ACPI_FAILURE (status)) {
 150                 acpi_ds_delete_walk_state (walk_state);
 151                 goto cleanup;
 152         }
 153
 154         /*
 155          * Parse the method, first pass
 156          *
 157          * The first pass load is where newly declared named objects are added into
 158          * the namespace.  Actual evaluation of the named objects (what would be
 159          * called a "second pass") happens during the actual execution of the
 160          * method so that operands to the named objects can take on dynamic
 161          * run-time values.
 162          */
 163         status = acpi_ps_parse_aml (walk_state);
 164         if (ACPI_FAILURE (status)) {
 165                 goto cleanup;
 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 cleanup:
 173         acpi_ps_delete_parse_tree (op);
 174         return_ACPI_STATUS (status);
 175 }
 176
 177
 178 /*******************************************************************************
 179  *
 180  * FUNCTION:    acpi_ds_begin_method_execution
 181  *
 182  * PARAMETERS:  method_node         - Node of the method
 183  *              obj_desc            - The method object
 184  *              calling_method_node - Caller of this method (if non-null)
 185  *
 186  * RETURN:      Status
 187  *
 188  * DESCRIPTION: Prepare a method for execution.  Parses the method if necessary,
 189  *              increments the thread count, and waits at the method semaphore
 190  *              for clearance to execute.
 191  *
 192  ******************************************************************************/
 193
 194 acpi_status
 195 acpi_ds_begin_method_execution (
 196         struct acpi_namespace_node      *method_node,
 197         union acpi_operand_object       *obj_desc,
 198         struct acpi_namespace_node      *calling_method_node)
 199 {
 200         acpi_status                     status = AE_OK;
 201
 202
 203         ACPI_FUNCTION_TRACE_PTR ("ds_begin_method_execution", method_node);
 204
 205
 206         if (!method_node) {
 207                 return_ACPI_STATUS (AE_NULL_ENTRY);
 208         }
 209
 210         /*
 211          * If there is a concurrency limit on this method, we need to
 212          * obtain a unit from the method semaphore.
 213          */
 214         if (obj_desc->method.semaphore) {
 215                 /*
 216                  * Allow recursive method calls, up to the reentrancy/concurrency
 217                  * limit imposed by the SERIALIZED rule and the sync_level method
 218                  * parameter.
 219                  *
 220                  * The point of this code is to avoid permanently blocking a
 221                  * thread that is making recursive method calls.
 222                  */
 223                 if (method_node == calling_method_node) {
 224                         if (obj_desc->method.thread_count >= obj_desc->method.concurrency) {
 225                                 return_ACPI_STATUS (AE_AML_METHOD_LIMIT);
 226                         }
 227                 }
 228
 229                 /*
 230                  * Get a unit from the method semaphore. This releases the
 231                  * interpreter if we block
 232                  */
 233                 status = acpi_ex_system_wait_semaphore (obj_desc->method.semaphore,
 234                                  ACPI_WAIT_FOREVER);
 235         }
 236
 237         /*
 238          * Increment the method parse tree thread count since it has been
 239          * reentered one more time (even if it is the same thread)
 240          */
 241         obj_desc->method.thread_count++;
 242         return_ACPI_STATUS (status);
 243 }
 244
 245
 246 /*******************************************************************************
 247  *
 248  * FUNCTION:    acpi_ds_call_control_method
 249  *
 250  * PARAMETERS:  Thread              - Info for this thread
 251  *              this_walk_state     - Current walk state
 252  *              Op                  - Current Op to be walked
 253  *
 254  * RETURN:      Status
 255  *
 256  * DESCRIPTION: Transfer execution to a called control method
 257  *
 258  ******************************************************************************/
 259
 260 acpi_status
 261 acpi_ds_call_control_method (
 262         struct acpi_thread_state        *thread,
 263         struct acpi_walk_state          *this_walk_state,
 264         union acpi_parse_object         *op)
 265 {
 266         acpi_status                     status;
 267         struct acpi_namespace_node      *method_node;
 268         struct acpi_walk_state          *next_walk_state;
 269         union acpi_operand_object       *obj_desc;
 270         struct acpi_parameter_info      info;
 271         u32                             i;
 272
 273
 274         ACPI_FUNCTION_TRACE_PTR ("ds_call_control_method", this_walk_state);
 275
 276         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "Execute method %p, currentstate=%p\n",
 277                 this_walk_state->prev_op, this_walk_state));
 278
 279         /*
 280          * Get the namespace entry for the control method we are about to call
 281          */
 282         method_node = this_walk_state->method_call_node;
 283         if (!method_node) {
 284                 return_ACPI_STATUS (AE_NULL_ENTRY);
 285         }
 286
 287         obj_desc = acpi_ns_get_attached_object (method_node);
 288         if (!obj_desc) {
 289                 return_ACPI_STATUS (AE_NULL_OBJECT);
 290         }
 291
 292         obj_desc->method.owning_id = acpi_ut_allocate_owner_id (ACPI_OWNER_TYPE_METHOD);
 293
 294         /* Init for new method, wait on concurrency semaphore */
 295
 296         status = acpi_ds_begin_method_execution (method_node, obj_desc,
 297                           this_walk_state->method_node);
 298         if (ACPI_FAILURE (status)) {
 299                 return_ACPI_STATUS (status);
 300         }
 301
 302         if (!(obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY)) {
 303                 /* 1) Parse: Create a new walk state for the preempting walk */
 304
 305                 next_walk_state = acpi_ds_create_walk_state (obj_desc->method.owning_id,
 306                                   op, obj_desc, NULL);
 307                 if (!next_walk_state) {
 308                         return_ACPI_STATUS (AE_NO_MEMORY);
 309                 }
 310
 311                 /* Create and init a Root Node */
 312
 313                 op = acpi_ps_create_scope_op ();
 314                 if (!op) {
 315                         status = AE_NO_MEMORY;
 316                         goto cleanup;
 317                 }
 318
 319                 status = acpi_ds_init_aml_walk (next_walk_state, op, method_node,
 320                                   obj_desc->method.aml_start, obj_desc->method.aml_length,
 321                                   NULL, 1);
 322                 if (ACPI_FAILURE (status)) {
 323                         acpi_ds_delete_walk_state (next_walk_state);
 324                         goto cleanup;
 325                 }
 326
 327                 /* Begin AML parse */
 328
 329                 status = acpi_ps_parse_aml (next_walk_state);
 330                 acpi_ps_delete_parse_tree (op);
 331         }
 332
 333         /* 2) Execute: Create a new state for the preempting walk */
 334
 335         next_walk_state = acpi_ds_create_walk_state (obj_desc->method.owning_id,
 336                           NULL, obj_desc, thread);
 337         if (!next_walk_state) {
 338                 status = AE_NO_MEMORY;
 339                 goto cleanup;
 340         }
 341         /*
 342          * The resolved arguments were put on the previous walk state's operand
 343          * stack.  Operands on the previous walk state stack always
 344          * start at index 0.
 345          * Null terminate the list of arguments
 346          */
 347         this_walk_state->operands [this_walk_state->num_operands] = NULL;
 348
 349         info.parameters = &this_walk_state->operands[0];
 350         info.parameter_type = ACPI_PARAM_ARGS;
 351
 352         status = acpi_ds_init_aml_walk (next_walk_state, NULL, method_node,
 353                           obj_desc->method.aml_start, obj_desc->method.aml_length,
 354                           &info, 3);
 355         if (ACPI_FAILURE (status)) {
 356                 goto cleanup;
 357         }
 358
 359         /*
 360          * Delete the operands on the previous walkstate operand stack
 361          * (they were copied to new objects)
 362          */
 363         for (i = 0; i < obj_desc->method.param_count; i++) {
 364                 acpi_ut_remove_reference (this_walk_state->operands [i]);
 365                 this_walk_state->operands [i] = NULL;
 366         }
 367
 368         /* Clear the operand stack */
 369
 370         this_walk_state->num_operands = 0;
 371
 372         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
 373                 "Starting nested execution, newstate=%p\n", next_walk_state));
 374
 375         if (obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY) {
 376                 status = obj_desc->method.implementation (next_walk_state);
 377                 return_ACPI_STATUS (status);
 378         }
 379
 380         return_ACPI_STATUS (AE_OK);
 381
 382
 383         /* On error, we must delete the new walk state */
 384
 385 cleanup:
 386         if (next_walk_state && (next_walk_state->method_desc)) {
 387                 /* Decrement the thread count on the method parse tree */
 388
 389            next_walk_state->method_desc->method.thread_count--;
 390         }
 391         (void) acpi_ds_terminate_control_method (next_walk_state);
 392         acpi_ds_delete_walk_state (next_walk_state);
 393         return_ACPI_STATUS (status);
 394 }
 395
 396
 397 /*******************************************************************************
 398  *
 399  * FUNCTION:    acpi_ds_restart_control_method
 400  *
 401  * PARAMETERS:  walk_state          - State for preempted method (caller)
 402  *              return_desc         - Return value from the called method
 403  *
 404  * RETURN:      Status
 405  *
 406  * DESCRIPTION: Restart a method that was preempted by another (nested) method
 407  *              invocation.  Handle the return value (if any) from the callee.
 408  *
 409  ******************************************************************************/
 410
 411 acpi_status
 412 acpi_ds_restart_control_method (
 413         struct acpi_walk_state          *walk_state,
 414         union acpi_operand_object       *return_desc)
 415 {
 416         acpi_status                     status;
 417
 418
 419         ACPI_FUNCTION_TRACE_PTR ("ds_restart_control_method", walk_state);
 420
 421
 422         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
 423                 "****Restart [%4.4s] Op %p return_value_from_callee %p\n",
 424                 (char *) &walk_state->method_node->name, walk_state->method_call_op,
 425                 return_desc));
 426
 427         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
 428                 "    return_from_this_method_used?=%X res_stack %p Walk %p\n",
 429                 walk_state->return_used,
 430                 walk_state->results, walk_state));
 431
 432         /* Did the called method return a value? */
 433
 434         if (return_desc) {
 435                 /* Are we actually going to use the return value? */
 436
 437                 if (walk_state->return_used) {
 438                         /* Save the return value from the previous method */
 439
 440                         status = acpi_ds_result_push (return_desc, walk_state);
 441                         if (ACPI_FAILURE (status)) {
 442                                 acpi_ut_remove_reference (return_desc);
 443                                 return_ACPI_STATUS (status);
 444                         }
 445
 446                         /*
 447                          * Save as THIS method's return value in case it is returned
 448                          * immediately to yet another method
 449                          */
 450                         walk_state->return_desc = return_desc;
 451                 }
 452
 453                 /*
 454                  * The following code is the
 455                  * optional support for a so-called "implicit return". Some AML code
 456                  * assumes that the last value of the method is "implicitly" returned
 457                  * to the caller. Just save the last result as the return value.
 458                  * NOTE: this is optional because the ASL language does not actually
 459                  * support this behavior.
 460                  */
 461                 else if (!acpi_ds_do_implicit_return (return_desc, walk_state, FALSE)) {
 462                         /*
 463                          * Delete the return value if it will not be used by the
 464                          * calling method
 465                          */
 466                         acpi_ut_remove_reference (return_desc);
 467                 }
 468         }
 469
 470         return_ACPI_STATUS (AE_OK);
 471 }
 472
 473
 474 /*******************************************************************************
 475  *
 476  * FUNCTION:    acpi_ds_terminate_control_method
 477  *
 478  * PARAMETERS:  walk_state          - State of the method
 479  *
 480  * RETURN:      Status
 481  *
 482  * DESCRIPTION: Terminate a control method.  Delete everything that the method
 483  *              created, delete all locals and arguments, and delete the parse
 484  *              tree if requested.
 485  *
 486  ******************************************************************************/
 487
 488 acpi_status
 489 acpi_ds_terminate_control_method (
 490         struct acpi_walk_state          *walk_state)
 491 {
 492         union acpi_operand_object       *obj_desc;
 493         struct acpi_namespace_node      *method_node;
 494         acpi_status                     status;
 495
 496
 497         ACPI_FUNCTION_TRACE_PTR ("ds_terminate_control_method", walk_state);
 498
 499
 500         if (!walk_state) {
 501                 return (AE_BAD_PARAMETER);
 502         }
 503
 504         /* The current method object was saved in the walk state */
 505
 506         obj_desc = walk_state->method_desc;
 507         if (!obj_desc) {
 508                 return_ACPI_STATUS (AE_OK);
 509         }
 510
 511         /* Delete all arguments and locals */
 512
 513         acpi_ds_method_data_delete_all (walk_state);
 514
 515         /*
 516          * Lock the parser while we terminate this method.
 517          * If this is the last thread executing the method,
 518          * we have additional cleanup to perform
 519          */
 520         status = acpi_ut_acquire_mutex (ACPI_MTX_PARSER);
 521         if (ACPI_FAILURE (status)) {
 522                 return_ACPI_STATUS (status);
 523         }
 524
 525         /* Signal completion of the execution of this method if necessary */
 526
 527         if (walk_state->method_desc->method.semaphore) {
 528                 status = acpi_os_signal_semaphore (
 529                                   walk_state->method_desc->method.semaphore, 1);
 530                 if (ACPI_FAILURE (status)) {
 531                         ACPI_REPORT_ERROR (("Could not signal method semaphore\n"));
 532                         status = AE_OK;
 533
 534                         /* Ignore error and continue cleanup */
 535                 }
 536         }
 537
 538         if (walk_state->method_desc->method.thread_count) {
 539                 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
 540                         "*** Not deleting method namespace, there are still %d threads\n",
 541                         walk_state->method_desc->method.thread_count));
 542         }
 543
 544         if (!walk_state->method_desc->method.thread_count) {
 545                 /*
 546                  * Support to dynamically change a method from not_serialized to
 547                  * Serialized if it appears that the method is written foolishly and
 548                  * does not support multiple thread execution.  The best example of this
 549                  * is if such a method creates namespace objects and blocks.  A second
 550                  * thread will fail with an AE_ALREADY_EXISTS exception
 551                  *
 552                  * This code is here because we must wait until the last thread exits
 553                  * before creating the synchronization semaphore.
 554                  */
 555                 if ((walk_state->method_desc->method.concurrency == 1) &&
 556                         (!walk_state->method_desc->method.semaphore)) {
 557                         status = acpi_os_create_semaphore (1,
 558                                          1,
 559                                          &walk_state->method_desc->method.semaphore);
 560                 }
 561
 562                 /*
 563                  * There are no more threads executing this method.  Perform
 564                  * additional cleanup.
 565                  *
 566                  * The method Node is stored in the walk state
 567                  */
 568                 method_node = walk_state->method_node;
 569
 570                 /*
 571                  * Delete any namespace entries created immediately underneath
 572                  * the method
 573                  */
 574                 status = acpi_ut_acquire_mutex (ACPI_MTX_NAMESPACE);
 575                 if (ACPI_FAILURE (status)) {
 576                         return_ACPI_STATUS (status);
 577                 }
 578
 579                 if (method_node->child) {
 580                         acpi_ns_delete_namespace_subtree (method_node);
 581                 }
 582
 583                 /*
 584                  * Delete any namespace entries created anywhere else within
 585                  * the namespace
 586                  */
 587                 acpi_ns_delete_namespace_by_owner (walk_state->method_desc->method.owning_id);
 588                 status = acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);
 589                 if (ACPI_FAILURE (status)) {
 590                         return_ACPI_STATUS (status);
 591                 }
 592         }
 593
 594         status = acpi_ut_release_mutex (ACPI_MTX_PARSER);
 595         return_ACPI_STATUS (status);
 596 }
 597
 598