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:  Node        - Method node
  62  *
  63  * RETURN:      Status
  64  *
  65  * DESCRIPTION: Parse the AML that is associated with the method.
  66  *
  67  * MUTEX:       Assumes parser is locked
  68  *
  69  ******************************************************************************/
  70
  71 acpi_status
  72 acpi_ds_parse_method (
  73         struct acpi_namespace_node      *node)
  74 {
  75         acpi_status                     status;
  76         union acpi_operand_object       *obj_desc;
  77         union acpi_parse_object         *op;
  78         struct acpi_walk_state          *walk_state;
  79
  80
  81         ACPI_FUNCTION_TRACE_PTR ("ds_parse_method", node);
  82
  83
  84         /* Parameter Validation */
  85
  86         if (!node) {
  87                 return_ACPI_STATUS (AE_NULL_ENTRY);
  88         }
  89
  90         ACPI_DEBUG_PRINT ((ACPI_DB_PARSE, "**** Parsing [%4.4s] **** named_obj=%p\n",
  91                 acpi_ut_get_node_name (node), node));
  92
  93         /* Extract the method object from the method Node */
  94
  95         obj_desc = acpi_ns_get_attached_object (node);
  96         if (!obj_desc) {
  97                 return_ACPI_STATUS (AE_NULL_OBJECT);
  98         }
  99
 100         /* Create a mutex for the method if there is a concurrency limit */
 101
 102         if ((obj_desc->method.concurrency != ACPI_INFINITE_CONCURRENCY) &&
 103                 (!obj_desc->method.semaphore)) {
 104                 status = acpi_os_create_semaphore (obj_desc->method.concurrency,
 105                                    obj_desc->method.concurrency,
 106                                    &obj_desc->method.semaphore);
 107                 if (ACPI_FAILURE (status)) {
 108                         return_ACPI_STATUS (status);
 109                 }
 110         }
 111
 112         /*
 113          * Allocate a new parser op to be the root of the parsed
 114          * method tree
 115          */
 116         op = acpi_ps_alloc_op (AML_METHOD_OP);
 117         if (!op) {
 118                 return_ACPI_STATUS (AE_NO_MEMORY);
 119         }
 120
 121         /* Init new op with the method name and pointer back to the Node */
 122
 123         acpi_ps_set_name (op, node->name.integer);
 124         op->common.node = node;
 125
 126         /*
 127          * Get a new owner_id for objects created by this method. Namespace
 128          * objects (such as Operation Regions) can be created during the
 129          * first pass parse.
 130          */
 131         status = acpi_ut_allocate_owner_id (&obj_desc->method.owner_id);
 132         if (ACPI_FAILURE (status)) {
 133                 goto cleanup;
 134         }
 135
 136         /* Create and initialize a new walk state */
 137
 138         walk_state = acpi_ds_create_walk_state (
 139                           obj_desc->method.owner_id, NULL, NULL, NULL);
 140         if (!walk_state) {
 141                 status = AE_NO_MEMORY;
 142                 goto cleanup2;
 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                 goto cleanup2;
 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                 goto cleanup2;
 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 (node), node, op));
 170
 171         /*
 172          * Delete the parse tree. We simply re-parse the method for every
 173          * execution since there isn't much overhead (compared to keeping lots
 174          * of parse trees around)
 175          */
 176         acpi_ns_delete_namespace_subtree (node);
 177         acpi_ns_delete_namespace_by_owner (obj_desc->method.owner_id);
 178
 179 cleanup2:
 180         acpi_ut_release_owner_id (&obj_desc->method.owner_id);
 181
 182 cleanup:
 183         acpi_ps_delete_parse_tree (op);
 184         return_ACPI_STATUS (status);
 185 }
 186
 187
 188 /*******************************************************************************
 189  *
 190  * FUNCTION:    acpi_ds_begin_method_execution
 191  *
 192  * PARAMETERS:  method_node         - Node of the method
 193  *              obj_desc            - The method object
 194  *              calling_method_node - Caller of this method (if non-null)
 195  *
 196  * RETURN:      Status
 197  *
 198  * DESCRIPTION: Prepare a method for execution.  Parses the method if necessary,
 199  *              increments the thread count, and waits at the method semaphore
 200  *              for clearance to execute.
 201  *
 202  ******************************************************************************/
 203
 204 acpi_status
 205 acpi_ds_begin_method_execution (
 206         struct acpi_namespace_node      *method_node,
 207         union acpi_operand_object       *obj_desc,
 208         struct acpi_namespace_node      *calling_method_node)
 209 {
 210         acpi_status                     status = AE_OK;
 211
 212
 213         ACPI_FUNCTION_TRACE_PTR ("ds_begin_method_execution", method_node);
 214
 215
 216         if (!method_node) {
 217                 return_ACPI_STATUS (AE_NULL_ENTRY);
 218         }
 219
 220         /*
 221          * If there is a concurrency limit on this method, we need to
 222          * obtain a unit from the method semaphore.
 223          */
 224         if (obj_desc->method.semaphore) {
 225                 /*
 226                  * Allow recursive method calls, up to the reentrancy/concurrency
 227                  * limit imposed by the SERIALIZED rule and the sync_level method
 228                  * parameter.
 229                  *
 230                  * The point of this code is to avoid permanently blocking a
 231                  * thread that is making recursive method calls.
 232                  */
 233                 if (method_node == calling_method_node) {
 234                         if (obj_desc->method.thread_count >= obj_desc->method.concurrency) {
 235                                 return_ACPI_STATUS (AE_AML_METHOD_LIMIT);
 236                         }
 237                 }
 238
 239                 /*
 240                  * Get a unit from the method semaphore. This releases the
 241                  * interpreter if we block
 242                  */
 243                 status = acpi_ex_system_wait_semaphore (obj_desc->method.semaphore,
 244                                  ACPI_WAIT_FOREVER);
 245         }
 246
 247         /*
 248          * Increment the method parse tree thread count since it has been
 249          * reentered one more time (even if it is the same thread)
 250          */
 251         obj_desc->method.thread_count++;
 252         return_ACPI_STATUS (status);
 253 }
 254
 255
 256 /*******************************************************************************
 257  *
 258  * FUNCTION:    acpi_ds_call_control_method
 259  *
 260  * PARAMETERS:  Thread              - Info for this thread
 261  *              this_walk_state     - Current walk state
 262  *              Op                  - Current Op to be walked
 263  *
 264  * RETURN:      Status
 265  *
 266  * DESCRIPTION: Transfer execution to a called control method
 267  *
 268  ******************************************************************************/
 269
 270 acpi_status
 271 acpi_ds_call_control_method (
 272         struct acpi_thread_state        *thread,
 273         struct acpi_walk_state          *this_walk_state,
 274         union acpi_parse_object         *op)
 275 {
 276         acpi_status                     status;
 277         struct acpi_namespace_node      *method_node;
 278         struct acpi_walk_state          *next_walk_state = NULL;
 279         union acpi_operand_object       *obj_desc;
 280         struct acpi_parameter_info      info;
 281         u32                             i;
 282
 283
 284         ACPI_FUNCTION_TRACE_PTR ("ds_call_control_method", this_walk_state);
 285
 286         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "Execute method %p, currentstate=%p\n",
 287                 this_walk_state->prev_op, this_walk_state));
 288
 289         /*
 290          * Get the namespace entry for the control method we are about to call
 291          */
 292         method_node = this_walk_state->method_call_node;
 293         if (!method_node) {
 294                 return_ACPI_STATUS (AE_NULL_ENTRY);
 295         }
 296
 297         obj_desc = acpi_ns_get_attached_object (method_node);
 298         if (!obj_desc) {
 299                 return_ACPI_STATUS (AE_NULL_OBJECT);
 300         }
 301
 302         status = acpi_ut_allocate_owner_id (&obj_desc->method.owner_id);
 303         if (ACPI_FAILURE (status)) {
 304                 return_ACPI_STATUS (status);
 305         }
 306
 307         /* Init for new method, wait on concurrency semaphore */
 308
 309         status = acpi_ds_begin_method_execution (method_node, obj_desc,
 310                           this_walk_state->method_node);
 311         if (ACPI_FAILURE (status)) {
 312                 goto cleanup;
 313         }
 314
 315         if (!(obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY)) {
 316                 /* 1) Parse: Create a new walk state for the preempting walk */
 317
 318                 next_walk_state = acpi_ds_create_walk_state (obj_desc->method.owner_id,
 319                                   op, obj_desc, NULL);
 320                 if (!next_walk_state) {
 321                         return_ACPI_STATUS (AE_NO_MEMORY);
 322                 }
 323
 324                 /* Create and init a Root Node */
 325
 326                 op = acpi_ps_create_scope_op ();
 327                 if (!op) {
 328                         status = AE_NO_MEMORY;
 329                         goto cleanup;
 330                 }
 331
 332                 status = acpi_ds_init_aml_walk (next_walk_state, op, method_node,
 333                                   obj_desc->method.aml_start, obj_desc->method.aml_length,
 334                                   NULL, 1);
 335                 if (ACPI_FAILURE (status)) {
 336                         acpi_ds_delete_walk_state (next_walk_state);
 337                         goto cleanup;
 338                 }
 339
 340                 /* Begin AML parse */
 341
 342                 status = acpi_ps_parse_aml (next_walk_state);
 343                 acpi_ps_delete_parse_tree (op);
 344         }
 345
 346         /* 2) Execute: Create a new state for the preempting walk */
 347
 348         next_walk_state = acpi_ds_create_walk_state (obj_desc->method.owner_id,
 349                           NULL, obj_desc, thread);
 350         if (!next_walk_state) {
 351                 status = AE_NO_MEMORY;
 352                 goto cleanup;
 353         }
 354         /*
 355          * The resolved arguments were put on the previous walk state's operand
 356          * stack.  Operands on the previous walk state stack always
 357          * start at index 0.
 358          * Null terminate the list of arguments
 359          */
 360         this_walk_state->operands [this_walk_state->num_operands] = NULL;
 361
 362         info.parameters = &this_walk_state->operands[0];
 363         info.parameter_type = ACPI_PARAM_ARGS;
 364
 365         status = acpi_ds_init_aml_walk (next_walk_state, NULL, method_node,
 366                           obj_desc->method.aml_start, obj_desc->method.aml_length,
 367                           &info, 3);
 368         if (ACPI_FAILURE (status)) {
 369                 goto cleanup;
 370         }
 371
 372         /*
 373          * Delete the operands on the previous walkstate operand stack
 374          * (they were copied to new objects)
 375          */
 376         for (i = 0; i < obj_desc->method.param_count; i++) {
 377                 acpi_ut_remove_reference (this_walk_state->operands [i]);
 378                 this_walk_state->operands [i] = NULL;
 379         }
 380
 381         /* Clear the operand stack */
 382
 383         this_walk_state->num_operands = 0;
 384
 385         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
 386                 "Starting nested execution, newstate=%p\n", next_walk_state));
 387
 388         if (obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY) {
 389                 status = obj_desc->method.implementation (next_walk_state);
 390                 return_ACPI_STATUS (status);
 391         }
 392
 393         return_ACPI_STATUS (AE_OK);
 394
 395
 396         /* On error, we must delete the new walk state */
 397
 398 cleanup:
 399         acpi_ut_release_owner_id (&obj_desc->method.owner_id);
 400         if (next_walk_state && (next_walk_state->method_desc)) {
 401                 /* Decrement the thread count on the method parse tree */
 402
 403            next_walk_state->method_desc->method.thread_count--;
 404         }
 405         (void) acpi_ds_terminate_control_method (next_walk_state);
 406         acpi_ds_delete_walk_state (next_walk_state);
 407         return_ACPI_STATUS (status);
 408 }
 409
 410
 411 /*******************************************************************************
 412  *
 413  * FUNCTION:    acpi_ds_restart_control_method
 414  *
 415  * PARAMETERS:  walk_state          - State for preempted method (caller)
 416  *              return_desc         - Return value from the called method
 417  *
 418  * RETURN:      Status
 419  *
 420  * DESCRIPTION: Restart a method that was preempted by another (nested) method
 421  *              invocation.  Handle the return value (if any) from the callee.
 422  *
 423  ******************************************************************************/
 424
 425 acpi_status
 426 acpi_ds_restart_control_method (
 427         struct acpi_walk_state          *walk_state,
 428         union acpi_operand_object       *return_desc)
 429 {
 430         acpi_status                     status;
 431
 432
 433         ACPI_FUNCTION_TRACE_PTR ("ds_restart_control_method", walk_state);
 434
 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, walk_state->method_call_op,
 439                 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 (return_desc, walk_state, FALSE)) {
 476                         /*
 477                          * Delete the return value if it will not be used by the
 478                          * calling method
 479                          */
 480                         acpi_ut_remove_reference (return_desc);
 481                 }
 482         }
 483
 484         return_ACPI_STATUS (AE_OK);
 485 }
 486
 487
 488 /*******************************************************************************
 489  *
 490  * FUNCTION:    acpi_ds_terminate_control_method
 491  *
 492  * PARAMETERS:  walk_state          - State of the method
 493  *
 494  * RETURN:      Status
 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 acpi_status
 503 acpi_ds_terminate_control_method (
 504         struct acpi_walk_state          *walk_state)
 505 {
 506         union acpi_operand_object       *obj_desc;
 507         struct acpi_namespace_node      *method_node;
 508         acpi_status                     status;
 509
 510
 511         ACPI_FUNCTION_TRACE_PTR ("ds_terminate_control_method", walk_state);
 512
 513
 514         if (!walk_state) {
 515                 return (AE_BAD_PARAMETER);
 516         }
 517
 518         /* The current method object was saved in the walk state */
 519
 520         obj_desc = walk_state->method_desc;
 521         if (!obj_desc) {
 522                 return_ACPI_STATUS (AE_OK);
 523         }
 524
 525         /* Delete all arguments and locals */
 526
 527         acpi_ds_method_data_delete_all (walk_state);
 528
 529         /*
 530          * Lock the parser while we terminate this method.
 531          * If this is the last thread executing the method,
 532          * we have additional cleanup to perform
 533          */
 534         status = acpi_ut_acquire_mutex (ACPI_MTX_PARSER);
 535         if (ACPI_FAILURE (status)) {
 536                 return_ACPI_STATUS (status);
 537         }
 538
 539         /* Signal completion of the execution of this method if necessary */
 540
 541         if (walk_state->method_desc->method.semaphore) {
 542                 status = acpi_os_signal_semaphore (
 543                                   walk_state->method_desc->method.semaphore, 1);
 544                 if (ACPI_FAILURE (status)) {
 545                         ACPI_REPORT_ERROR (("Could not signal method semaphore\n"));
 546                         status = AE_OK;
 547
 548                         /* Ignore error and continue cleanup */
 549                 }
 550         }
 551
 552         if (walk_state->method_desc->method.thread_count) {
 553                 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
 554                         "*** Not deleting method namespace, there are still %d threads\n",
 555                         walk_state->method_desc->method.thread_count));
 556         }
 557
 558         if (!walk_state->method_desc->method.thread_count) {
 559                 /*
 560                  * Support to dynamically change a method from not_serialized to
 561                  * Serialized if it appears that the method is written foolishly and
 562                  * does not support multiple thread execution.  The best example of this
 563                  * is if such a method creates namespace objects and blocks.  A second
 564                  * thread will fail with an AE_ALREADY_EXISTS exception
 565                  *
 566                  * This code is here because we must wait until the last thread exits
 567                  * before creating the synchronization semaphore.
 568                  */
 569                 if ((walk_state->method_desc->method.concurrency == 1) &&
 570                         (!walk_state->method_desc->method.semaphore)) {
 571                         status = acpi_os_create_semaphore (1, 1,
 572                                          &walk_state->method_desc->method.semaphore);
 573                 }
 574
 575                 /*
 576                  * There are no more threads executing this method.  Perform
 577                  * additional cleanup.
 578                  *
 579                  * The method Node is stored in the walk state
 580                  */
 581                 method_node = walk_state->method_node;
 582
 583                 /*
 584                  * Delete any namespace entries created immediately underneath
 585                  * the method
 586                  */
 587                 status = acpi_ut_acquire_mutex (ACPI_MTX_NAMESPACE);
 588                 if (ACPI_FAILURE (status)) {
 589                         return_ACPI_STATUS (status);
 590                 }
 591
 592                 if (method_node->child) {
 593                         acpi_ns_delete_namespace_subtree (method_node);
 594                 }
 595
 596                 /*
 597                  * Delete any namespace entries created anywhere else within
 598                  * the namespace
 599                  */
 600                 acpi_ns_delete_namespace_by_owner (walk_state->method_desc->method.owner_id);
 601                 status = acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);
 602                 acpi_ut_release_owner_id (&walk_state->method_desc->method.owner_id);
 603
 604                 if (ACPI_FAILURE (status)) {
 605                         return_ACPI_STATUS (status);
 606                 }
 607         }
 608
 609         status = acpi_ut_release_mutex (ACPI_MTX_PARSER);
 610         return_ACPI_STATUS (status);
 611 }
 612
 613