drivers/bus/acpi/dispatcher/dsmethod.c

   1 /******************************************************************************
   2  *
   3  * Module Name: dsmethod - Parser/Interpreter interface - control method parsing
   4  *              $Revision$
   5  *
   6  *****************************************************************************/
   7
   8 /*
   9  *  Copyright (C) 2000, 2001 R. Byron Moore
  10  *
  11  *  This program is free software; you can redistribute it and/or modify
  12  *  it under the terms of the GNU General Public License as published by
  13  *  the Free Software Foundation; either version 2 of the License, or
  14  *  (at your option) any later version.
  15  *
  16  *  This program is distributed in the hope that it will be useful,
  17  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  *  GNU General Public License for more details.
  20  *
  21  *  You should have received a copy of the GNU General Public License
  22  *  along with this program; if not, write to the Free Software
  23  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  24  */
  25
  26
  27 #include "acpi.h"
  28 #include "acparser.h"
  29 #include "amlcode.h"
  30 #include "acdispat.h"
  31 #include "acinterp.h"
  32 #include "acnamesp.h"
  33 #include "actables.h"
  34 #include "acdebug.h"
  35
  36
  37 #define _COMPONENT          ACPI_DISPATCHER
  38          MODULE_NAME         ("dsmethod")
  39
  40
  41 /*******************************************************************************
  42  *
  43  * FUNCTION:    Acpi_ds_parse_method
  44  *
  45  * PARAMETERS:  Obj_handle      - Node of the method
  46  *              Level           - Current nesting level
  47  *              Context         - Points to a method counter
  48  *              Return_value    - Not used
  49  *
  50  * RETURN:      Status
  51  *
  52  * DESCRIPTION: Call the parser and parse the AML that is
  53  *              associated with the method.
  54  *
  55  * MUTEX:       Assumes parser is locked
  56  *
  57  ******************************************************************************/
  58
  59 ACPI_STATUS
  60 acpi_ds_parse_method (
  61         ACPI_HANDLE             obj_handle)
  62 {
  63         ACPI_STATUS             status;
  64         ACPI_OPERAND_OBJECT     *obj_desc;
  65         ACPI_PARSE_OBJECT       *op;
  66         ACPI_NAMESPACE_NODE     *node;
  67         ACPI_OWNER_ID           owner_id;
  68
  69
  70         /* Parameter Validation */
  71
  72         if (!obj_handle) {
  73                 return (AE_NULL_ENTRY);
  74         }
  75
  76
  77         /* Extract the method object from the method Node */
  78
  79         node = (ACPI_NAMESPACE_NODE *) obj_handle;
  80         obj_desc = node->object;
  81         if (!obj_desc) {
  82                 return (AE_NULL_OBJECT);
  83         }
  84
  85          /* Create a mutex for the method if there is a concurrency limit */
  86
  87         if ((obj_desc->method.concurrency != INFINITE_CONCURRENCY) &&
  88                 (!obj_desc->method.semaphore)) {
  89                 status = acpi_os_create_semaphore (obj_desc->method.concurrency,
  90                                    obj_desc->method.concurrency,
  91                                    &obj_desc->method.semaphore);
  92                 if (ACPI_FAILURE (status)) {
  93                         return (status);
  94                 }
  95         }
  96
  97         /*
  98          * Allocate a new parser op to be the root of the parsed
  99          * method tree
 100          */
 101         op = acpi_ps_alloc_op (AML_METHOD_OP);
 102         if (!op) {
 103                 return (AE_NO_MEMORY);
 104         }
 105
 106         /* Init new op with the method name and pointer back to the Node */
 107
 108         acpi_ps_set_name (op, node->name);
 109         op->node = node;
 110
 111
 112         /*
 113          * Parse the method, first pass
 114          *
 115          * The first pass load is
 116          * where newly declared named objects are
 117          * added into the namespace.  Actual evaluation of
 118          * the named objects (what would be called a "second
 119          * pass") happens during the actual execution of the
 120          * method so that operands to the named objects can
 121          * take on dynamic run-time values.
 122          */
 123         status = acpi_ps_parse_aml (op, obj_desc->method.pcode,
 124                            obj_desc->method.pcode_length,
 125                            ACPI_PARSE_LOAD_PASS1 | ACPI_PARSE_DELETE_TREE,
 126                            node, NULL, NULL,
 127                            acpi_ds_load1_begin_op, acpi_ds_load1_end_op);
 128
 129         if (ACPI_FAILURE (status)) {
 130                 return (status);
 131         }
 132
 133         /* Get a new Owner_id for objects created by this method */
 134
 135         owner_id = acpi_cm_allocate_owner_id (OWNER_TYPE_METHOD);
 136         obj_desc->method.owning_id = owner_id;
 137
 138         /* Install the parsed tree in the method object */
 139         /* TBD: [Restructure] Obsolete field? */
 140
 141         acpi_ps_delete_parse_tree (op);
 142
 143
 144         return (status);
 145 }
 146
 147
 148 /*******************************************************************************
 149  *
 150  * FUNCTION:    Acpi_ds_begin_method_execution
 151  *
 152  * PARAMETERS:  Method_node         - Node of the method
 153  *              Obj_desc            - The method object
 154  *              Calling_method_node - Caller of this method (if non-null)
 155  *
 156  * RETURN:      Status
 157  *
 158  * DESCRIPTION: Prepare a method for execution.  Parses the method if necessary,
 159  *              increments the thread count, and waits at the method semaphore
 160  *              for clearance to execute.
 161  *
 162  * MUTEX:       Locks/unlocks parser.
 163  *
 164  ******************************************************************************/
 165
 166 ACPI_STATUS
 167 acpi_ds_begin_method_execution (
 168         ACPI_NAMESPACE_NODE     *method_node,
 169         ACPI_OPERAND_OBJECT     *obj_desc,
 170         ACPI_NAMESPACE_NODE     *calling_method_node)
 171 {
 172         ACPI_STATUS             status = AE_OK;
 173
 174
 175         if (!method_node) {
 176                 return (AE_NULL_ENTRY);
 177         }
 178
 179
 180         /*
 181          * If there is a concurrency limit on this method, we need to
 182          * obtain a unit from the method semaphore.
 183          */
 184         if (obj_desc->method.semaphore) {
 185                 /*
 186                  * Allow recursive method calls, up to the reentrancy/concurrency
 187                  * limit imposed by the SERIALIZED rule and the Sync_level method
 188                  * parameter.
 189                  *
 190                  * The point of this code is to avoid permanently blocking a
 191                  * thread that is making recursive method calls.
 192                  */
 193                 if (method_node == calling_method_node) {
 194                         if (obj_desc->method.thread_count >= obj_desc->method.concurrency) {
 195                                 return (AE_AML_METHOD_LIMIT);
 196                         }
 197                 }
 198
 199                 /*
 200                  * Get a unit from the method semaphore. This releases the
 201                  * interpreter if we block
 202                  */
 203                 status = acpi_aml_system_wait_semaphore (obj_desc->method.semaphore,
 204                                  WAIT_FOREVER);
 205         }
 206
 207
 208         /*
 209          * Increment the method parse tree thread count since it has been
 210          * reentered one more time (even if it is the same thread)
 211          */
 212         obj_desc->method.thread_count++;
 213
 214         return (status);
 215 }
 216
 217
 218 /*******************************************************************************
 219  *
 220  * FUNCTION:    Acpi_ds_call_control_method
 221  *
 222  * PARAMETERS:  Walk_state          - Current state of the walk
 223  *              Op                  - Current Op to be walked
 224  *
 225  * RETURN:      Status
 226  *
 227  * DESCRIPTION: Transfer execution to a called control method
 228  *
 229  ******************************************************************************/
 230
 231 ACPI_STATUS
 232 acpi_ds_call_control_method (
 233         ACPI_WALK_LIST          *walk_list,
 234         ACPI_WALK_STATE         *this_walk_state,
 235         ACPI_PARSE_OBJECT       *op)
 236 {
 237         ACPI_STATUS             status;
 238         ACPI_NAMESPACE_NODE     *method_node;
 239         ACPI_OPERAND_OBJECT     *obj_desc;
 240         ACPI_WALK_STATE         *next_walk_state;
 241         ACPI_PARSE_STATE        *parser_state;
 242         u32                     i;
 243
 244
 245         /*
 246          * Get the namespace entry for the control method we are about to call
 247          */
 248         method_node = this_walk_state->method_call_node;
 249         if (!method_node) {
 250                 return (AE_NULL_ENTRY);
 251         }
 252
 253         obj_desc = acpi_ns_get_attached_object (method_node);
 254         if (!obj_desc) {
 255                 return (AE_NULL_OBJECT);
 256         }
 257
 258
 259         /* Init for new method, wait on concurrency semaphore */
 260
 261         status = acpi_ds_begin_method_execution (method_node, obj_desc,
 262                           this_walk_state->method_node);
 263         if (ACPI_FAILURE (status)) {
 264                 return (status);
 265         }
 266
 267         /* Create and initialize a new parser state */
 268
 269         parser_state = acpi_ps_create_state (obj_desc->method.pcode,
 270                            obj_desc->method.pcode_length);
 271         if (!parser_state) {
 272                 return (AE_NO_MEMORY);
 273         }
 274
 275         acpi_ps_init_scope (parser_state, NULL);
 276         parser_state->start_node = method_node;
 277
 278
 279         /* Create a new state for the preempting walk */
 280
 281         next_walk_state = acpi_ds_create_walk_state (obj_desc->method.owning_id,
 282                           NULL, obj_desc, walk_list);
 283         if (!next_walk_state) {
 284                 /* TBD: delete parser state */
 285
 286                 return (AE_NO_MEMORY);
 287         }
 288
 289         next_walk_state->walk_type          = WALK_METHOD;
 290         next_walk_state->method_node        = method_node;
 291         next_walk_state->parser_state       = parser_state;
 292         next_walk_state->parse_flags        = this_walk_state->parse_flags;
 293         next_walk_state->descending_callback = this_walk_state->descending_callback;
 294         next_walk_state->ascending_callback = this_walk_state->ascending_callback;
 295
 296         /* The Next_op of the Next_walk will be the beginning of the method */
 297         /* TBD: [Restructure] -- obsolete? */
 298
 299         next_walk_state->next_op = NULL;
 300
 301         /* Open a new scope */
 302
 303         status = acpi_ds_scope_stack_push (method_node,
 304                            ACPI_TYPE_METHOD, next_walk_state);
 305         if (ACPI_FAILURE (status)) {
 306                 goto cleanup;
 307         }
 308
 309
 310         /*
 311          * Initialize the arguments for the method.  The resolved
 312          * arguments were put on the previous walk state's operand
 313          * stack.  Operands on the previous walk state stack always
 314          * start at index 0.
 315          */
 316         status = acpi_ds_method_data_init_args (&this_walk_state->operands[0],
 317                          this_walk_state->num_operands,
 318                          next_walk_state);
 319         if (ACPI_FAILURE (status)) {
 320                 goto cleanup;
 321         }
 322
 323
 324         /* Create and init a Root Node */
 325
 326         op = acpi_ps_alloc_op (AML_SCOPE_OP);
 327         if (!op) {
 328                 return (AE_NO_MEMORY);
 329         }
 330
 331         status = acpi_ps_parse_aml (op, obj_desc->method.pcode,
 332                           obj_desc->method.pcode_length,
 333                           ACPI_PARSE_LOAD_PASS1 | ACPI_PARSE_DELETE_TREE,
 334                           method_node, NULL, NULL,
 335                           acpi_ds_load1_begin_op, acpi_ds_load1_end_op);
 336         acpi_ps_delete_parse_tree (op);
 337
 338
 339         /*
 340          * Delete the operands on the previous walkstate operand stack
 341          * (they were copied to new objects)
 342          */
 343         for (i = 0; i < obj_desc->method.param_count; i++) {
 344                 acpi_cm_remove_reference (this_walk_state->operands [i]);
 345                 this_walk_state->operands [i] = NULL;
 346         }
 347
 348         /* Clear the operand stack */
 349
 350         this_walk_state->num_operands = 0;
 351
 352
 353         return (AE_OK);
 354
 355
 356         /* On error, we must delete the new walk state */
 357
 358 cleanup:
 359         acpi_ds_terminate_control_method (next_walk_state);
 360         acpi_ds_delete_walk_state (next_walk_state);
 361         return (status);
 362
 363 }
 364
 365
 366 /*******************************************************************************
 367  *
 368  * FUNCTION:    Acpi_ds_restart_control_method
 369  *
 370  * PARAMETERS:  Walk_state          - State of the method when it was preempted
 371  *              Op                  - Pointer to new current op
 372  *
 373  * RETURN:      Status
 374  *
 375  * DESCRIPTION: Restart a method that was preempted
 376  *
 377  ******************************************************************************/
 378
 379 ACPI_STATUS
 380 acpi_ds_restart_control_method (
 381         ACPI_WALK_STATE         *walk_state,
 382         ACPI_OPERAND_OBJECT     *return_desc)
 383 {
 384         ACPI_STATUS             status;
 385
 386
 387         if (return_desc) {
 388                 if (walk_state->return_used) {
 389                         /*
 390                          * Get the return value (if any) from the previous method.
 391                          * NULL if no return value
 392                          */
 393                         status = acpi_ds_result_push (return_desc, walk_state);
 394                         if (ACPI_FAILURE (status)) {
 395                                 acpi_cm_remove_reference (return_desc);
 396                                 return (status);
 397                         }
 398                 }
 399
 400                 else {
 401                         /*
 402                          * Delete the return value if it will not be used by the
 403                          * calling method
 404                          */
 405                         acpi_cm_remove_reference (return_desc);
 406                 }
 407
 408         }
 409
 410
 411         return (AE_OK);
 412 }
 413
 414
 415 /*******************************************************************************
 416  *
 417  * FUNCTION:    Acpi_ds_terminate_control_method
 418  *
 419  * PARAMETERS:  Walk_state          - State of the method
 420  *
 421  * RETURN:      Status
 422  *
 423  * DESCRIPTION: Terminate a control method.  Delete everything that the method
 424  *              created, delete all locals and arguments, and delete the parse
 425  *              tree if requested.
 426  *
 427  ******************************************************************************/
 428
 429 ACPI_STATUS
 430 acpi_ds_terminate_control_method (
 431         ACPI_WALK_STATE         *walk_state)
 432 {
 433         ACPI_STATUS             status;
 434         ACPI_OPERAND_OBJECT     *obj_desc;
 435         ACPI_NAMESPACE_NODE     *method_node;
 436
 437
 438         /* The method object should be stored in the walk state */
 439
 440         obj_desc = walk_state->method_desc;
 441         if (!obj_desc) {
 442                 return (AE_OK);
 443         }
 444
 445         /* Delete all arguments and locals */
 446
 447         acpi_ds_method_data_delete_all (walk_state);
 448
 449         /*
 450          * Lock the parser while we terminate this method.
 451          * If this is the last thread executing the method,
 452          * we have additional cleanup to perform
 453          */
 454         acpi_cm_acquire_mutex (ACPI_MTX_PARSER);
 455
 456
 457         /* Signal completion of the execution of this method if necessary */
 458
 459         if (walk_state->method_desc->method.semaphore) {
 460                 status = acpi_os_signal_semaphore (
 461                                  walk_state->method_desc->method.semaphore, 1);
 462         }
 463
 464         /* Decrement the thread count on the method parse tree */
 465
 466         walk_state->method_desc->method.thread_count--;
 467         if (!walk_state->method_desc->method.thread_count) {
 468                 /*
 469                  * There are no more threads executing this method.  Perform
 470                  * additional cleanup.
 471                  *
 472                  * The method Node is stored in the walk state
 473                  */
 474                 method_node = walk_state->method_node;
 475
 476                 /*
 477                  * Delete any namespace entries created immediately underneath
 478                  * the method
 479                  */
 480                 acpi_cm_acquire_mutex (ACPI_MTX_NAMESPACE);
 481                 if (method_node->child) {
 482                         acpi_ns_delete_namespace_subtree (method_node);
 483                 }
 484
 485                 /*
 486                  * Delete any namespace entries created anywhere else within
 487                  * the namespace
 488                  */
 489                 acpi_ns_delete_namespace_by_owner (walk_state->method_desc->method.owning_id);
 490                 acpi_cm_release_mutex (ACPI_MTX_NAMESPACE);
 491         }
 492
 493         acpi_cm_release_mutex (ACPI_MTX_PARSER);
 494         return (AE_OK);
 495 }
 496
 497