drivers/acpi/dispatcher/dsutils.c

   1 /*******************************************************************************
   2  *
   3  * Module Name: dsutils - Dispatcher utilities
   4  *
   5  ******************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2004, 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 #include <acpi/acdebug.h>
  52
  53 #define _COMPONENT          ACPI_DISPATCHER
  54          ACPI_MODULE_NAME    ("dsutils")
  55
  56
  57 #ifndef ACPI_NO_METHOD_EXECUTION
  58
  59 /*******************************************************************************
  60  *
  61  * FUNCTION:    acpi_ds_is_result_used
  62  *
  63  * PARAMETERS:  Op
  64  *              result_obj
  65  *              walk_state
  66  *
  67  * RETURN:      Status
  68  *
  69  * DESCRIPTION: Check if a result object will be used by the parent
  70  *
  71  ******************************************************************************/
  72
  73 u8
  74 acpi_ds_is_result_used (
  75         union acpi_parse_object         *op,
  76         struct acpi_walk_state          *walk_state)
  77 {
  78         const struct acpi_opcode_info   *parent_info;
  79
  80
  81         ACPI_FUNCTION_TRACE_PTR ("ds_is_result_used", op);
  82
  83
  84         /* Must have both an Op and a Result Object */
  85
  86         if (!op) {
  87                 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Null Op\n"));
  88                 return_VALUE (TRUE);
  89         }
  90
  91         /*
  92          * If there is no parent, the result can't possibly be used!
  93          * (An executing method typically has no parent, since each
  94          * method is parsed separately)  However, a method that is
  95          * invoked from another method has a parent.
  96          */
  97         if (!op->common.parent) {
  98                 return_VALUE (FALSE);
  99         }
 100
 101         /*
 102          * Get info on the parent.  The root Op is AML_SCOPE
 103          */
 104         parent_info = acpi_ps_get_opcode_info (op->common.parent->common.aml_opcode);
 105         if (parent_info->class == AML_CLASS_UNKNOWN) {
 106                 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Unknown parent opcode. Op=%p\n", op));
 107                 return_VALUE (FALSE);
 108         }
 109
 110         /*
 111          * Decide what to do with the result based on the parent.  If
 112          * the parent opcode will not use the result, delete the object.
 113          * Otherwise leave it as is, it will be deleted when it is used
 114          * as an operand later.
 115          */
 116         switch (parent_info->class) {
 117         case AML_CLASS_CONTROL:
 118
 119                 switch (op->common.parent->common.aml_opcode) {
 120                 case AML_RETURN_OP:
 121
 122                         /* Never delete the return value associated with a return opcode */
 123
 124                         goto result_used;
 125
 126                 case AML_IF_OP:
 127                 case AML_WHILE_OP:
 128
 129                         /*
 130                          * If we are executing the predicate AND this is the predicate op,
 131                          * we will use the return value
 132                          */
 133                         if ((walk_state->control_state->common.state == ACPI_CONTROL_PREDICATE_EXECUTING) &&
 134                                 (walk_state->control_state->control.predicate_op == op)) {
 135                                 goto result_used;
 136                         }
 137                         break;
 138
 139                 default:
 140                         /* Ignore other control opcodes */
 141                         break;
 142                 }
 143
 144                 /* The general control opcode returns no result */
 145
 146                 goto result_not_used;
 147
 148
 149         case AML_CLASS_CREATE:
 150
 151                 /*
 152                  * These opcodes allow term_arg(s) as operands and therefore
 153                  * the operands can be method calls.  The result is used.
 154                  */
 155                 goto result_used;
 156
 157
 158         case AML_CLASS_NAMED_OBJECT:
 159
 160                 if ((op->common.parent->common.aml_opcode == AML_REGION_OP)      ||
 161                         (op->common.parent->common.aml_opcode == AML_DATA_REGION_OP) ||
 162                         (op->common.parent->common.aml_opcode == AML_PACKAGE_OP)     ||
 163                         (op->common.parent->common.aml_opcode == AML_VAR_PACKAGE_OP) ||
 164                         (op->common.parent->common.aml_opcode == AML_BUFFER_OP)      ||
 165                         (op->common.parent->common.aml_opcode == AML_INT_EVAL_SUBTREE_OP)) {
 166                         /*
 167                          * These opcodes allow term_arg(s) as operands and therefore
 168                          * the operands can be method calls.  The result is used.
 169                          */
 170                         goto result_used;
 171                 }
 172
 173                 goto result_not_used;
 174
 175
 176         default:
 177
 178                 /*
 179                  * In all other cases. the parent will actually use the return
 180                  * object, so keep it.
 181                  */
 182                 goto result_used;
 183         }
 184
 185
 186 result_used:
 187         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "Result of [%s] used by Parent [%s] Op=%p\n",
 188                         acpi_ps_get_opcode_name (op->common.aml_opcode),
 189                         acpi_ps_get_opcode_name (op->common.parent->common.aml_opcode), op));
 190
 191         return_VALUE (TRUE);
 192
 193
 194 result_not_used:
 195         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "Result of [%s] not used by Parent [%s] Op=%p\n",
 196                         acpi_ps_get_opcode_name (op->common.aml_opcode),
 197                         acpi_ps_get_opcode_name (op->common.parent->common.aml_opcode), op));
 198
 199         return_VALUE (FALSE);
 200 }
 201
 202
 203 /*******************************************************************************
 204  *
 205  * FUNCTION:    acpi_ds_delete_result_if_not_used
 206  *
 207  * PARAMETERS:  Op
 208  *              result_obj
 209  *              walk_state
 210  *
 211  * RETURN:      Status
 212  *
 213  * DESCRIPTION: Used after interpretation of an opcode.  If there is an internal
 214  *              result descriptor, check if the parent opcode will actually use
 215  *              this result.  If not, delete the result now so that it will
 216  *              not become orphaned.
 217  *
 218  ******************************************************************************/
 219
 220 void
 221 acpi_ds_delete_result_if_not_used (
 222         union acpi_parse_object         *op,
 223         union acpi_operand_object       *result_obj,
 224         struct acpi_walk_state          *walk_state)
 225 {
 226         union acpi_operand_object       *obj_desc;
 227         acpi_status                     status;
 228
 229
 230         ACPI_FUNCTION_TRACE_PTR ("ds_delete_result_if_not_used", result_obj);
 231
 232
 233         if (!op) {
 234                 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Null Op\n"));
 235                 return_VOID;
 236         }
 237
 238         if (!result_obj) {
 239                 return_VOID;
 240         }
 241
 242         if (!acpi_ds_is_result_used (op, walk_state)) {
 243                 /*
 244                  * Must pop the result stack (obj_desc should be equal to result_obj)
 245                  */
 246                 status = acpi_ds_result_pop (&obj_desc, walk_state);
 247                 if (ACPI_SUCCESS (status)) {
 248                         acpi_ut_remove_reference (result_obj);
 249                 }
 250         }
 251
 252         return_VOID;
 253 }
 254
 255
 256 /*******************************************************************************
 257  *
 258  * FUNCTION:    acpi_ds_resolve_operands
 259  *
 260  * PARAMETERS:  walk_state          - Current walk state with operands on stack
 261  *
 262  * RETURN:      Status
 263  *
 264  * DESCRIPTION: Resolve all operands to their values.  Used to prepare
 265  *              arguments to a control method invocation (a call from one
 266  *              method to another.)
 267  *
 268  ******************************************************************************/
 269
 270 acpi_status
 271 acpi_ds_resolve_operands (
 272         struct acpi_walk_state          *walk_state)
 273 {
 274         u32                             i;
 275         acpi_status                     status = AE_OK;
 276
 277
 278         ACPI_FUNCTION_TRACE_PTR ("ds_resolve_operands", walk_state);
 279
 280
 281         /*
 282          * Attempt to resolve each of the valid operands
 283          * Method arguments are passed by reference, not by value.  This means
 284          * that the actual objects are passed, not copies of the objects.
 285          */
 286         for (i = 0; i < walk_state->num_operands; i++) {
 287                 status = acpi_ex_resolve_to_value (&walk_state->operands[i], walk_state);
 288                 if (ACPI_FAILURE (status)) {
 289                         break;
 290                 }
 291         }
 292
 293         return_ACPI_STATUS (status);
 294 }
 295
 296
 297 /*******************************************************************************
 298  *
 299  * FUNCTION:    acpi_ds_clear_operands
 300  *
 301  * PARAMETERS:  walk_state          - Current walk state with operands on stack
 302  *
 303  * RETURN:      None
 304  *
 305  * DESCRIPTION: Clear all operands on the current walk state operand stack.
 306  *
 307  ******************************************************************************/
 308
 309 void
 310 acpi_ds_clear_operands (
 311         struct acpi_walk_state          *walk_state)
 312 {
 313         u32                             i;
 314
 315
 316         ACPI_FUNCTION_TRACE_PTR ("acpi_ds_clear_operands", walk_state);
 317
 318
 319         /*
 320          * Remove a reference on each operand on the stack
 321          */
 322         for (i = 0; i < walk_state->num_operands; i++) {
 323                 /*
 324                  * Remove a reference to all operands, including both
 325                  * "Arguments" and "Targets".
 326                  */
 327                 acpi_ut_remove_reference (walk_state->operands[i]);
 328                 walk_state->operands[i] = NULL;
 329         }
 330
 331         walk_state->num_operands = 0;
 332         return_VOID;
 333 }
 334 #endif
 335
 336
 337 /*******************************************************************************
 338  *
 339  * FUNCTION:    acpi_ds_create_operand
 340  *
 341  * PARAMETERS:  walk_state
 342  *              Arg
 343  *
 344  * RETURN:      Status
 345  *
 346  * DESCRIPTION: Translate a parse tree object that is an argument to an AML
 347  *              opcode to the equivalent interpreter object.  This may include
 348  *              looking up a name or entering a new name into the internal
 349  *              namespace.
 350  *
 351  ******************************************************************************/
 352
 353 acpi_status
 354 acpi_ds_create_operand (
 355         struct acpi_walk_state          *walk_state,
 356         union acpi_parse_object         *arg,
 357         u32                             arg_index)
 358 {
 359         acpi_status                     status = AE_OK;
 360         char                            *name_string;
 361         u32                             name_length;
 362         union acpi_operand_object       *obj_desc;
 363         union acpi_parse_object         *parent_op;
 364         u16                             opcode;
 365         acpi_interpreter_mode           interpreter_mode;
 366         const struct acpi_opcode_info   *op_info;
 367
 368
 369         ACPI_FUNCTION_TRACE_PTR ("ds_create_operand", arg);
 370
 371
 372         /* A valid name must be looked up in the namespace */
 373
 374         if ((arg->common.aml_opcode == AML_INT_NAMEPATH_OP) &&
 375                 (arg->common.value.string)) {
 376                 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "Getting a name: Arg=%p\n", arg));
 377
 378                 /* Get the entire name string from the AML stream */
 379
 380                 status = acpi_ex_get_name_string (ACPI_TYPE_ANY, arg->common.value.buffer,
 381                                   &name_string, &name_length);
 382
 383                 if (ACPI_FAILURE (status)) {
 384                         return_ACPI_STATUS (status);
 385                 }
 386
 387                 /*
 388                  * All prefixes have been handled, and the name is
 389                  * in name_string
 390                  */
 391
 392
 393                 /*
 394                  * Special handling for buffer_field declarations. This is a deferred
 395                  * opcode that unfortunately defines the field name as the last
 396                  * parameter instead of the first.  We get here when we are performing
 397                  * the deferred execution, so the actual name of the field is already
 398                  * in the namespace.  We don't want to attempt to look it up again
 399                  * because we may be executing in a different scope than where the
 400                  * actual opcode exists.
 401                  */
 402                 if ((walk_state->deferred_node) &&
 403                         (walk_state->deferred_node->type == ACPI_TYPE_BUFFER_FIELD) &&
 404                         (arg_index != 0)) {
 405                         obj_desc = ACPI_CAST_PTR (union acpi_operand_object, walk_state->deferred_node);
 406                         status = AE_OK;
 407                 }
 408                 else    /* All other opcodes */ {
 409                         /*
 410                          * Differentiate between a namespace "create" operation
 411                          * versus a "lookup" operation (IMODE_LOAD_PASS2 vs.
 412                          * IMODE_EXECUTE) in order to support the creation of
 413                          * namespace objects during the execution of control methods.
 414                          */
 415                         parent_op = arg->common.parent;
 416                         op_info = acpi_ps_get_opcode_info (parent_op->common.aml_opcode);
 417                         if ((op_info->flags & AML_NSNODE) &&
 418                                 (parent_op->common.aml_opcode != AML_INT_METHODCALL_OP) &&
 419                                 (parent_op->common.aml_opcode != AML_REGION_OP) &&
 420                                 (parent_op->common.aml_opcode != AML_INT_NAMEPATH_OP)) {
 421                                 /* Enter name into namespace if not found */
 422
 423                                 interpreter_mode = ACPI_IMODE_LOAD_PASS2;
 424                         }
 425                         else {
 426                                 /* Return a failure if name not found */
 427
 428                                 interpreter_mode = ACPI_IMODE_EXECUTE;
 429                         }
 430
 431                         status = acpi_ns_lookup (walk_state->scope_info, name_string,
 432                                          ACPI_TYPE_ANY, interpreter_mode,
 433                                          ACPI_NS_SEARCH_PARENT | ACPI_NS_DONT_OPEN_SCOPE,
 434                                          walk_state,
 435                                          ACPI_CAST_INDIRECT_PTR (struct acpi_namespace_node, &obj_desc));
 436                         /*
 437                          * The only case where we pass through (ignore) a NOT_FOUND
 438                          * error is for the cond_ref_of opcode.
 439                          */
 440                         if (status == AE_NOT_FOUND) {
 441                                 if (parent_op->common.aml_opcode == AML_COND_REF_OF_OP) {
 442                                         /*
 443                                          * For the Conditional Reference op, it's OK if
 444                                          * the name is not found;  We just need a way to
 445                                          * indicate this to the interpreter, set the
 446                                          * object to the root
 447                                          */
 448                                         obj_desc = ACPI_CAST_PTR (union acpi_operand_object, acpi_gbl_root_node);
 449                                         status = AE_OK;
 450                                 }
 451                                 else {
 452                                         /*
 453                                          * We just plain didn't find it -- which is a
 454                                          * very serious error at this point
 455                                          */
 456                                         status = AE_AML_NAME_NOT_FOUND;
 457                                 }
 458                         }
 459
 460                         if (ACPI_FAILURE (status)) {
 461                                 ACPI_REPORT_NSERROR (name_string, status);
 462                         }
 463                 }
 464
 465                 /* Free the namestring created above */
 466
 467                 ACPI_MEM_FREE (name_string);
 468
 469                 /* Check status from the lookup */
 470
 471                 if (ACPI_FAILURE (status)) {
 472                         return_ACPI_STATUS (status);
 473                 }
 474
 475                 /* Put the resulting object onto the current object stack */
 476
 477                 status = acpi_ds_obj_stack_push (obj_desc, walk_state);
 478                 if (ACPI_FAILURE (status)) {
 479                         return_ACPI_STATUS (status);
 480                 }
 481                 ACPI_DEBUGGER_EXEC (acpi_db_display_argument_object (obj_desc, walk_state));
 482         }
 483         else {
 484                 /* Check for null name case */
 485
 486                 if (arg->common.aml_opcode == AML_INT_NAMEPATH_OP) {
 487                         /*
 488                          * If the name is null, this means that this is an
 489                          * optional result parameter that was not specified
 490                          * in the original ASL.  Create a Zero Constant for a
 491                          * placeholder.  (Store to a constant is a Noop.)
 492                          */
 493                         opcode = AML_ZERO_OP;       /* Has no arguments! */
 494
 495                         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "Null namepath: Arg=%p\n", arg));
 496                 }
 497                 else {
 498                         opcode = arg->common.aml_opcode;
 499                 }
 500
 501                 /* Get the object type of the argument */
 502
 503                 op_info = acpi_ps_get_opcode_info (opcode);
 504                 if (op_info->object_type == ACPI_TYPE_INVALID) {
 505                         return_ACPI_STATUS (AE_NOT_IMPLEMENTED);
 506                 }
 507
 508                 if (op_info->flags & AML_HAS_RETVAL) {
 509                         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
 510                                 "Argument previously created, already stacked \n"));
 511
 512                         ACPI_DEBUGGER_EXEC (acpi_db_display_argument_object (
 513                                 walk_state->operands [walk_state->num_operands - 1], walk_state));
 514
 515                         /*
 516                          * Use value that was already previously returned
 517                          * by the evaluation of this argument
 518                          */
 519                         status = acpi_ds_result_pop_from_bottom (&obj_desc, walk_state);
 520                         if (ACPI_FAILURE (status)) {
 521                                 /*
 522                                  * Only error is underflow, and this indicates
 523                                  * a missing or null operand!
 524                                  */
 525                                 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Missing or null operand, %s\n",
 526                                         acpi_format_exception (status)));
 527                                 return_ACPI_STATUS (status);
 528                         }
 529                 }
 530                 else {
 531                         /* Create an ACPI_INTERNAL_OBJECT for the argument */
 532
 533                         obj_desc = acpi_ut_create_internal_object (op_info->object_type);
 534                         if (!obj_desc) {
 535                                 return_ACPI_STATUS (AE_NO_MEMORY);
 536                         }
 537
 538                         /* Initialize the new object */
 539
 540                         status = acpi_ds_init_object_from_op (walk_state, arg,
 541                                          opcode, &obj_desc);
 542                         if (ACPI_FAILURE (status)) {
 543                                 acpi_ut_delete_object_desc (obj_desc);
 544                                 return_ACPI_STATUS (status);
 545                         }
 546                 }
 547
 548                 /* Put the operand object on the object stack */
 549
 550                 status = acpi_ds_obj_stack_push (obj_desc, walk_state);
 551                 if (ACPI_FAILURE (status)) {
 552                         return_ACPI_STATUS (status);
 553                 }
 554
 555                 ACPI_DEBUGGER_EXEC (acpi_db_display_argument_object (obj_desc, walk_state));
 556         }
 557
 558         return_ACPI_STATUS (AE_OK);
 559 }
 560
 561
 562 /*******************************************************************************
 563  *
 564  * FUNCTION:    acpi_ds_create_operands
 565  *
 566  * PARAMETERS:  first_arg           - First argument of a parser argument tree
 567  *
 568  * RETURN:      Status
 569  *
 570  * DESCRIPTION: Convert an operator's arguments from a parse tree format to
 571  *              namespace objects and place those argument object on the object
 572  *              stack in preparation for evaluation by the interpreter.
 573  *
 574  ******************************************************************************/
 575
 576 acpi_status
 577 acpi_ds_create_operands (
 578         struct acpi_walk_state          *walk_state,
 579         union acpi_parse_object         *first_arg)
 580 {
 581         acpi_status                     status = AE_OK;
 582         union acpi_parse_object         *arg;
 583         u32                             arg_count = 0;
 584
 585
 586         ACPI_FUNCTION_TRACE_PTR ("ds_create_operands", first_arg);
 587
 588
 589         /* For all arguments in the list... */
 590
 591         arg = first_arg;
 592         while (arg) {
 593                 status = acpi_ds_create_operand (walk_state, arg, arg_count);
 594                 if (ACPI_FAILURE (status)) {
 595                         goto cleanup;
 596                 }
 597
 598                 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "Arg #%d (%p) done, Arg1=%p\n",
 599                         arg_count, arg, first_arg));
 600
 601                 /* Move on to next argument, if any */
 602
 603                 arg = arg->common.next;
 604                 arg_count++;
 605         }
 606
 607         return_ACPI_STATUS (status);
 608
 609
 610 cleanup:
 611         /*
 612          * We must undo everything done above; meaning that we must
 613          * pop everything off of the operand stack and delete those
 614          * objects
 615          */
 616         (void) acpi_ds_obj_stack_pop_and_delete (arg_count, walk_state);
 617
 618         ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "While creating Arg %d - %s\n",
 619                 (arg_count + 1), acpi_format_exception (status)));
 620         return_ACPI_STATUS (status);
 621 }
 622
 623