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 #include <acpi/acpi.h>
  45 #include <acpi/acparser.h>
  46 #include <acpi/amlcode.h>
  47 #include <acpi/acdispat.h>
  48 #include <acpi/acinterp.h>
  49 #include <acpi/acnamesp.h>
  50
  51 #define _COMPONENT          ACPI_DISPATCHER
  52 ACPI_MODULE_NAME("dsmethod")
  53
  54 /*******************************************************************************
  55  *
  56  * FUNCTION:    acpi_ds_parse_method
  57  *
  58  * PARAMETERS:  Node        - Method node
  59  *
  60  * RETURN:      Status
  61  *
  62  * DESCRIPTION: Parse the AML that is associated with the method.
  63  *
  64  * MUTEX:       Assumes parser is locked
  65  *
  66  ******************************************************************************/
  67 acpi_status acpi_ds_parse_method(struct acpi_namespace_node *node)
  68 {
  69         acpi_status status;
  70         union acpi_operand_object *obj_desc;
  71         union acpi_parse_object *op;
  72         struct acpi_walk_state *walk_state;
  73
  74         ACPI_FUNCTION_TRACE_PTR("ds_parse_method", node);
  75
  76         /* Parameter Validation */
  77
  78         if (!node) {
  79                 return_ACPI_STATUS(AE_NULL_ENTRY);
  80         }
  81
  82         ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
  83                           "**** Parsing [%4.4s] **** named_obj=%p\n",
  84                           acpi_ut_get_node_name(node), node));
  85
  86         /* Extract the method object from the method Node */
  87
  88         obj_desc = acpi_ns_get_attached_object(node);
  89         if (!obj_desc) {
  90                 return_ACPI_STATUS(AE_NULL_OBJECT);
  91         }
  92
  93         /* Create a mutex for the method if there is a concurrency limit */
  94
  95         if ((obj_desc->method.concurrency != ACPI_INFINITE_CONCURRENCY) &&
  96             (!obj_desc->method.semaphore)) {
  97                 status = acpi_os_create_semaphore(obj_desc->method.concurrency,
  98                                                   obj_desc->method.concurrency,
  99                                                   &obj_desc->method.semaphore);
 100                 if (ACPI_FAILURE(status)) {
 101                         return_ACPI_STATUS(status);
 102                 }
 103         }
 104
 105         /*
 106          * Allocate a new parser op to be the root of the parsed
 107          * method tree
 108          */
 109         op = acpi_ps_alloc_op(AML_METHOD_OP);
 110         if (!op) {
 111                 return_ACPI_STATUS(AE_NO_MEMORY);
 112         }
 113
 114         /* Init new op with the method name and pointer back to the Node */
 115
 116         acpi_ps_set_name(op, node->name.integer);
 117         op->common.node = node;
 118
 119         /*
 120          * Get a new owner_id for objects created by this method. Namespace
 121          * objects (such as Operation Regions) can be created during the
 122          * first pass parse.
 123          */
 124         status = acpi_ut_allocate_owner_id(&obj_desc->method.owner_id);
 125         if (ACPI_FAILURE(status)) {
 126                 goto cleanup;
 127         }
 128
 129         /* Create and initialize a new walk state */
 130
 131         walk_state =
 132             acpi_ds_create_walk_state(obj_desc->method.owner_id, NULL, NULL,
 133                                       NULL);
 134         if (!walk_state) {
 135                 status = AE_NO_MEMORY;
 136                 goto cleanup2;
 137         }
 138
 139         status = acpi_ds_init_aml_walk(walk_state, op, node,
 140                                        obj_desc->method.aml_start,
 141                                        obj_desc->method.aml_length, NULL, 1);
 142         if (ACPI_FAILURE(status)) {
 143                 acpi_ds_delete_walk_state(walk_state);
 144                 goto cleanup2;
 145         }
 146
 147         /*
 148          * Parse the method, first pass
 149          *
 150          * The first pass load is where newly declared named objects are added into
 151          * the namespace.  Actual evaluation of the named objects (what would be
 152          * called a "second pass") happens during the actual execution of the
 153          * method so that operands to the named objects can take on dynamic
 154          * run-time values.
 155          */
 156         status = acpi_ps_parse_aml(walk_state);
 157         if (ACPI_FAILURE(status)) {
 158                 goto cleanup2;
 159         }
 160
 161         ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 162                           "**** [%4.4s] Parsed **** named_obj=%p Op=%p\n",
 163                           acpi_ut_get_node_name(node), node, op));
 164
 165         /*
 166          * Delete the parse tree. We simply re-parse the method for every
 167          * execution since there isn't much overhead (compared to keeping lots
 168          * of parse trees around)
 169          */
 170         acpi_ns_delete_namespace_subtree(node);
 171         acpi_ns_delete_namespace_by_owner(obj_desc->method.owner_id);
 172
 173       cleanup2:
 174         acpi_ut_release_owner_id(&obj_desc->method.owner_id);
 175
 176       cleanup:
 177         acpi_ps_delete_parse_tree(op);
 178         return_ACPI_STATUS(status);
 179 }
 180
 181 /*******************************************************************************
 182  *
 183  * FUNCTION:    acpi_ds_begin_method_execution
 184  *
 185  * PARAMETERS:  method_node         - Node of the method
 186  *              obj_desc            - The method object
 187  *              calling_method_node - Caller of this method (if non-null)
 188  *
 189  * RETURN:      Status
 190  *
 191  * DESCRIPTION: Prepare a method for execution.  Parses the method if necessary,
 192  *              increments the thread count, and waits at the method semaphore
 193  *              for clearance to execute.
 194  *
 195  ******************************************************************************/
 196
 197 acpi_status
 198 acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node,
 199                                union acpi_operand_object *obj_desc,
 200                                struct acpi_namespace_node *calling_method_node)
 201 {
 202         acpi_status status = AE_OK;
 203
 204         ACPI_FUNCTION_TRACE_PTR("ds_begin_method_execution", method_node);
 205
 206         if (!method_node) {
 207                 return_ACPI_STATUS(AE_NULL_ENTRY);
 208         }
 209
 210         /* Prevent wraparound of thread count */
 211
 212         if (obj_desc->method.thread_count == ACPI_UINT8_MAX) {
 213                 ACPI_REPORT_ERROR(("Method reached maximum reentrancy limit (255)\n"));
 214                 return_ACPI_STATUS(AE_AML_METHOD_LIMIT);
 215         }
 216
 217         /*
 218          * If there is a concurrency limit on this method, we need to
 219          * obtain a unit from the method semaphore.
 220          */
 221         if (obj_desc->method.semaphore) {
 222                 /*
 223                  * Allow recursive method calls, up to the reentrancy/concurrency
 224                  * limit imposed by the SERIALIZED rule and the sync_level method
 225                  * parameter.
 226                  *
 227                  * The point of this code is to avoid permanently blocking a
 228                  * thread that is making recursive method calls.
 229                  */
 230                 if (method_node == calling_method_node) {
 231                         if (obj_desc->method.thread_count >=
 232                             obj_desc->method.concurrency) {
 233                                 return_ACPI_STATUS(AE_AML_METHOD_LIMIT);
 234                         }
 235                 }
 236
 237                 /*
 238                  * Get a unit from the method semaphore. This releases the
 239                  * interpreter if we block
 240                  */
 241                 status =
 242                     acpi_ex_system_wait_semaphore(obj_desc->method.semaphore,
 243                                                   ACPI_WAIT_FOREVER);
 244         }
 245
 246         /*
 247          * Allocate an Owner ID for this method, only if this is the first thread
 248          * to begin concurrent execution. We only need one owner_id, even if the
 249          * method is invoked recursively.
 250          */
 251         if (!obj_desc->method.owner_id) {
 252                 status = acpi_ut_allocate_owner_id(&obj_desc->method.owner_id);
 253                 if (ACPI_FAILURE(status)) {
 254                         return_ACPI_STATUS(status);
 255                 }
 256         }
 257
 258         /*
 259          * Increment the method parse tree thread count since it has been
 260          * reentered one more time (even if it is the same thread)
 261          */
 262         obj_desc->method.thread_count++;
 263         return_ACPI_STATUS(status);
 264 }
 265
 266 /*******************************************************************************
 267  *
 268  * FUNCTION:    acpi_ds_call_control_method
 269  *
 270  * PARAMETERS:  Thread              - Info for this thread
 271  *              this_walk_state     - Current walk state
 272  *              Op                  - Current Op to be walked
 273  *
 274  * RETURN:      Status
 275  *
 276  * DESCRIPTION: Transfer execution to a called control method
 277  *
 278  ******************************************************************************/
 279
 280 acpi_status
 281 acpi_ds_call_control_method(struct acpi_thread_state *thread,
 282                             struct acpi_walk_state *this_walk_state,
 283                             union acpi_parse_object *op)
 284 {
 285         acpi_status status;
 286         struct acpi_namespace_node *method_node;
 287         struct acpi_walk_state *next_walk_state = NULL;
 288         union acpi_operand_object *obj_desc;
 289         struct acpi_parameter_info info;
 290         u32 i;
 291
 292         ACPI_FUNCTION_TRACE_PTR("ds_call_control_method", this_walk_state);
 293
 294         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 295                           "Execute method %p, currentstate=%p\n",
 296                           this_walk_state->prev_op, this_walk_state));
 297
 298         /*
 299          * Get the namespace entry for the control method we are about to call
 300          */
 301         method_node = this_walk_state->method_call_node;
 302         if (!method_node) {
 303                 return_ACPI_STATUS(AE_NULL_ENTRY);
 304         }
 305
 306         obj_desc = acpi_ns_get_attached_object(method_node);
 307         if (!obj_desc) {
 308                 return_ACPI_STATUS(AE_NULL_OBJECT);
 309         }
 310
 311         /* Init for new method, wait on concurrency semaphore */
 312
 313         status = acpi_ds_begin_method_execution(method_node, obj_desc,
 314                                                 this_walk_state->method_node);
 315         if (ACPI_FAILURE(status)) {
 316                 goto cleanup;
 317         }
 318
 319         if (!(obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY)) {
 320                 /* 1) Parse: Create a new walk state for the preempting walk */
 321
 322                 next_walk_state =
 323                     acpi_ds_create_walk_state(obj_desc->method.owner_id, op,
 324                                               obj_desc, NULL);
 325                 if (!next_walk_state) {
 326                         return_ACPI_STATUS(AE_NO_MEMORY);
 327                 }
 328
 329                 /* Create and init a Root Node */
 330
 331                 op = acpi_ps_create_scope_op();
 332                 if (!op) {
 333                         status = AE_NO_MEMORY;
 334                         goto cleanup;
 335                 }
 336
 337                 status = acpi_ds_init_aml_walk(next_walk_state, op, method_node,
 338                                                obj_desc->method.aml_start,
 339                                                obj_desc->method.aml_length,
 340                                                NULL, 1);
 341                 if (ACPI_FAILURE(status)) {
 342                         acpi_ds_delete_walk_state(next_walk_state);
 343                         goto cleanup;
 344                 }
 345
 346                 /* Begin AML parse */
 347
 348                 status = acpi_ps_parse_aml(next_walk_state);
 349                 acpi_ps_delete_parse_tree(op);
 350         }
 351
 352         /* 2) Execute: Create a new state for the preempting walk */
 353
 354         next_walk_state = acpi_ds_create_walk_state(obj_desc->method.owner_id,
 355                                                     NULL, obj_desc, thread);
 356         if (!next_walk_state) {
 357                 status = AE_NO_MEMORY;
 358                 goto cleanup;
 359         }
 360         /*
 361          * The resolved arguments were put on the previous walk state's operand
 362          * stack. Operands on the previous walk state stack always
 363          * start at index 0. Also, null terminate the list of arguments
 364          */
 365         this_walk_state->operands[this_walk_state->num_operands] = NULL;
 366
 367         info.parameters = &this_walk_state->operands[0];
 368         info.parameter_type = ACPI_PARAM_ARGS;
 369
 370         status = acpi_ds_init_aml_walk(next_walk_state, NULL, method_node,
 371                                        obj_desc->method.aml_start,
 372                                        obj_desc->method.aml_length, &info, 3);
 373         if (ACPI_FAILURE(status)) {
 374                 goto cleanup;
 375         }
 376
 377         /*
 378          * Delete the operands on the previous walkstate operand stack
 379          * (they were copied to new objects)
 380          */
 381         for (i = 0; i < obj_desc->method.param_count; i++) {
 382                 acpi_ut_remove_reference(this_walk_state->operands[i]);
 383                 this_walk_state->operands[i] = NULL;
 384         }
 385
 386         /* Clear the operand stack */
 387
 388         this_walk_state->num_operands = 0;
 389
 390         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 391                           "Starting nested execution, newstate=%p\n",
 392                           next_walk_state));
 393
 394         if (obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY) {
 395                 status = obj_desc->method.implementation(next_walk_state);
 396         }
 397
 398         return_ACPI_STATUS(status);
 399
 400       cleanup:
 401         /* Decrement the thread count on the method parse tree */
 402
 403         if (next_walk_state && (next_walk_state->method_desc)) {
 404                 next_walk_state->method_desc->method.thread_count--;
 405         }
 406
 407         /* On error, we must delete the new walk state */
 408
 409         acpi_ds_terminate_control_method(next_walk_state);
 410         acpi_ds_delete_walk_state(next_walk_state);
 411         return_ACPI_STATUS(status);
 412 }
 413
 414 /*******************************************************************************
 415  *
 416  * FUNCTION:    acpi_ds_restart_control_method
 417  *
 418  * PARAMETERS:  walk_state          - State for preempted method (caller)
 419  *              return_desc         - Return value from the called method
 420  *
 421  * RETURN:      Status
 422  *
 423  * DESCRIPTION: Restart a method that was preempted by another (nested) method
 424  *              invocation.  Handle the return value (if any) from the callee.
 425  *
 426  ******************************************************************************/
 427
 428 acpi_status
 429 acpi_ds_restart_control_method(struct acpi_walk_state *walk_state,
 430                                union acpi_operand_object *return_desc)
 431 {
 432         acpi_status status;
 433
 434         ACPI_FUNCTION_TRACE_PTR("ds_restart_control_method", walk_state);
 435
 436         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 437                           "****Restart [%4.4s] Op %p return_value_from_callee %p\n",
 438                           (char *)&walk_state->method_node->name,
 439                           walk_state->method_call_op, return_desc));
 440
 441         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 442                           "    return_from_this_method_used?=%X res_stack %p Walk %p\n",
 443                           walk_state->return_used,
 444                           walk_state->results, walk_state));
 445
 446         /* Did the called method return a value? */
 447
 448         if (return_desc) {
 449                 /* Are we actually going to use the return value? */
 450
 451                 if (walk_state->return_used) {
 452                         /* Save the return value from the previous method */
 453
 454                         status = acpi_ds_result_push(return_desc, walk_state);
 455                         if (ACPI_FAILURE(status)) {
 456                                 acpi_ut_remove_reference(return_desc);
 457                                 return_ACPI_STATUS(status);
 458                         }
 459
 460                         /*
 461                          * Save as THIS method's return value in case it is returned
 462                          * immediately to yet another method
 463                          */
 464                         walk_state->return_desc = return_desc;
 465                 }
 466
 467                 /*
 468                  * The following code is the
 469                  * optional support for a so-called "implicit return". Some AML code
 470                  * assumes that the last value of the method is "implicitly" returned
 471                  * to the caller. Just save the last result as the return value.
 472                  * NOTE: this is optional because the ASL language does not actually
 473                  * support this behavior.
 474                  */
 475                 else if (!acpi_ds_do_implicit_return
 476                          (return_desc, walk_state, FALSE)) {
 477                         /*
 478                          * Delete the return value if it will not be used by the
 479                          * calling method
 480                          */
 481                         acpi_ut_remove_reference(return_desc);
 482                 }
 483         }
 484
 485         return_ACPI_STATUS(AE_OK);
 486 }
 487
 488 /*******************************************************************************
 489  *
 490  * FUNCTION:    acpi_ds_terminate_control_method
 491  *
 492  * PARAMETERS:  walk_state          - State of the method
 493  *
 494  * RETURN:      None
 495  *
 496  * DESCRIPTION: Terminate a control method.  Delete everything that the method
 497  *              created, delete all locals and arguments, and delete the parse
 498  *              tree if requested.
 499  *
 500  ******************************************************************************/
 501
 502 void acpi_ds_terminate_control_method(struct acpi_walk_state *walk_state)
 503 {
 504         union acpi_operand_object *obj_desc;
 505         struct acpi_namespace_node *method_node;
 506         acpi_status status;
 507
 508         ACPI_FUNCTION_TRACE_PTR("ds_terminate_control_method", walk_state);
 509
 510         if (!walk_state) {
 511                 return_VOID;
 512         }
 513
 514         /* The current method object was saved in the walk state */
 515
 516         obj_desc = walk_state->method_desc;
 517         if (!obj_desc) {
 518                 return_VOID;
 519         }
 520
 521         /* Delete all arguments and locals */
 522
 523         acpi_ds_method_data_delete_all(walk_state);
 524
 525         /*
 526          * Lock the parser while we terminate this method.
 527          * If this is the last thread executing the method,
 528          * we have additional cleanup to perform
 529          */
 530         status = acpi_ut_acquire_mutex(ACPI_MTX_PARSER);
 531         if (ACPI_FAILURE(status)) {
 532                 return_VOID;
 533         }
 534
 535         /* Signal completion of the execution of this method if necessary */
 536
 537         if (walk_state->method_desc->method.semaphore) {
 538                 status =
 539                     acpi_os_signal_semaphore(walk_state->method_desc->method.
 540                                              semaphore, 1);
 541                 if (ACPI_FAILURE(status)) {
 542                         ACPI_REPORT_ERROR(("Could not signal method semaphore\n"));
 543
 544                         /* Ignore error and continue cleanup */
 545                 }
 546         }
 547
 548         if (walk_state->method_desc->method.thread_count) {
 549                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 550                                   "*** Not deleting method namespace, there are still %d threads\n",
 551                                   walk_state->method_desc->method.
 552                                   thread_count));
 553         } else {                /* This is the last executing thread */
 554
 555                 /*
 556                  * Support to dynamically change a method from not_serialized to
 557                  * Serialized if it appears that the method is written foolishly and
 558                  * does not support multiple thread execution.  The best example of this
 559                  * is if such a method creates namespace objects and blocks.  A second
 560                  * thread will fail with an AE_ALREADY_EXISTS exception
 561                  *
 562                  * This code is here because we must wait until the last thread exits
 563                  * before creating the synchronization semaphore.
 564                  */
 565                 if ((walk_state->method_desc->method.concurrency == 1) &&
 566                     (!walk_state->method_desc->method.semaphore)) {
 567                         status = acpi_os_create_semaphore(1, 1,
 568                                                           &walk_state->
 569                                                           method_desc->method.
 570                                                           semaphore);
 571                 }
 572
 573                 /*
 574                  * There are no more threads executing this method.  Perform
 575                  * additional cleanup.
 576                  *
 577                  * The method Node is stored in the walk state
 578                  */
 579                 method_node = walk_state->method_node;
 580
 581                 /*
 582                  * Delete any namespace entries created immediately underneath
 583                  * the method
 584                  */
 585                 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 586                 if (ACPI_FAILURE(status)) {
 587                         goto exit;
 588                 }
 589
 590                 if (method_node->child) {
 591                         acpi_ns_delete_namespace_subtree(method_node);
 592                 }
 593
 594                 /*
 595                  * Delete any namespace entries created anywhere else within
 596                  * the namespace
 597                  */
 598                 acpi_ns_delete_namespace_by_owner(walk_state->method_desc->
 599                                                   method.owner_id);
 600                 status = acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 601                 acpi_ut_release_owner_id(&walk_state->method_desc->method.
 602                                          owner_id);
 603         }
 604
 605       exit:
 606         (void)acpi_ut_release_mutex(ACPI_MTX_PARSER);
 607         return_VOID;
 608 }