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