drivers/acpi/acpica/nseval.c

   1 /*******************************************************************************
   2  *
   3  * Module Name: nseval - Object evaluation, includes control method execution
   4  *
   5  ******************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2013, Intel Corp.
   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 "accommon.h"
  46 #include "acparser.h"
  47 #include "acinterp.h"
  48 #include "acnamesp.h"
  49
  50 #define _COMPONENT          ACPI_NAMESPACE
  51 ACPI_MODULE_NAME("nseval")
  52
  53 /* Local prototypes */
  54 static void
  55 acpi_ns_exec_module_code(union acpi_operand_object *method_obj,
  56                          struct acpi_evaluate_info *info);
  57
  58 /*******************************************************************************
  59  *
  60  * FUNCTION:    acpi_ns_evaluate
  61  *
  62  * PARAMETERS:  info            - Evaluation info block, contains:
  63  *                  prefix_node     - Prefix or Method/Object Node to execute
  64  *                  pathname        - Name of method to execute, If NULL, the
  65  *                                    Node is the object to execute
  66  *                  parameters      - List of parameters to pass to the method,
  67  *                                    terminated by NULL. Params itself may be
  68  *                                    NULL if no parameters are being passed.
  69  *                  return_object   - Where to put method's return value (if
  70  *                                    any). If NULL, no value is returned.
  71  *                  parameter_type  - Type of Parameter list
  72  *                  return_object   - Where to put method's return value (if
  73  *                                    any). If NULL, no value is returned.
  74  *                  flags           - ACPI_IGNORE_RETURN_VALUE to delete return
  75  *
  76  * RETURN:      Status
  77  *
  78  * DESCRIPTION: Execute a control method or return the current value of an
  79  *              ACPI namespace object.
  80  *
  81  * MUTEX:       Locks interpreter
  82  *
  83  ******************************************************************************/
  84
  85 acpi_status acpi_ns_evaluate(struct acpi_evaluate_info * info)
  86 {
  87         acpi_status status;
  88         struct acpi_namespace_node *node;
  89
  90         ACPI_FUNCTION_TRACE(ns_evaluate);
  91
  92         if (!info) {
  93                 return_ACPI_STATUS(AE_BAD_PARAMETER);
  94         }
  95
  96         /* Initialize the return value to an invalid object */
  97
  98         info->return_object = NULL;
  99         info->param_count = 0;
 100
 101         if (!info->resolved_node) {
 102                 /*
 103                  * Get the actual namespace node for the target object if we need to.
 104                  * Handles these cases:
 105                  *
 106                  * 1) Null node, Pathname (absolute path)
 107                  * 2) Node, Pathname (path relative to Node)
 108                  * 3) Node, Null Pathname
 109                  */
 110                 status = acpi_ns_get_node(info->prefix_node, info->pathname,
 111                                           ACPI_NS_NO_UPSEARCH,
 112                                           &info->resolved_node);
 113                 if (ACPI_FAILURE(status)) {
 114                         return_ACPI_STATUS(status);
 115                 }
 116         }
 117
 118         /*
 119          * For a method alias, we must grab the actual method node so that proper
 120          * scoping context will be established before execution.
 121          */
 122         if (acpi_ns_get_type(info->resolved_node) ==
 123             ACPI_TYPE_LOCAL_METHOD_ALIAS) {
 124                 info->resolved_node =
 125                     ACPI_CAST_PTR(struct acpi_namespace_node,
 126                                   info->resolved_node->object);
 127         }
 128
 129         ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "%s [%p] Value %p\n", info->pathname,
 130                           info->resolved_node,
 131                           acpi_ns_get_attached_object(info->resolved_node)));
 132
 133         node = info->resolved_node;
 134
 135         /*
 136          * Two major cases here:
 137          *
 138          * 1) The object is a control method -- execute it
 139          * 2) The object is not a method -- just return it's current value
 140          */
 141         if (acpi_ns_get_type(info->resolved_node) == ACPI_TYPE_METHOD) {
 142                 /*
 143                  * 1) Object is a control method - execute it
 144                  */
 145
 146                 /* Verify that there is a method object associated with this node */
 147
 148                 info->obj_desc =
 149                     acpi_ns_get_attached_object(info->resolved_node);
 150                 if (!info->obj_desc) {
 151                         ACPI_ERROR((AE_INFO,
 152                                     "Control method has no attached sub-object"));
 153                         return_ACPI_STATUS(AE_NULL_OBJECT);
 154                 }
 155
 156                 /* Count the number of arguments being passed to the method */
 157
 158                 if (info->parameters) {
 159                         while (info->parameters[info->param_count]) {
 160                                 if (info->param_count > ACPI_METHOD_MAX_ARG) {
 161                                         return_ACPI_STATUS(AE_LIMIT);
 162                                 }
 163                                 info->param_count++;
 164                         }
 165                 }
 166
 167
 168                 ACPI_DUMP_PATHNAME(info->resolved_node, "ACPI: Execute Method",
 169                                    ACPI_LV_INFO, _COMPONENT);
 170
 171                 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
 172                                   "Method at AML address %p Length %X\n",
 173                                   info->obj_desc->method.aml_start + 1,
 174                                   info->obj_desc->method.aml_length - 1));
 175
 176                 /*
 177                  * Any namespace deletion must acquire both the namespace and
 178                  * interpreter locks to ensure that no thread is using the portion of
 179                  * the namespace that is being deleted.
 180                  *
 181                  * Execute the method via the interpreter. The interpreter is locked
 182                  * here before calling into the AML parser
 183                  */
 184                 acpi_ex_enter_interpreter();
 185                 status = acpi_ps_execute_method(info);
 186                 acpi_ex_exit_interpreter();
 187         } else {
 188                 /*
 189                  * 2) Object is not a method, return its current value
 190                  *
 191                  * Disallow certain object types. For these, "evaluation" is undefined.
 192                  */
 193                 switch (info->resolved_node->type) {
 194                 case ACPI_TYPE_DEVICE:
 195                 case ACPI_TYPE_EVENT:
 196                 case ACPI_TYPE_MUTEX:
 197                 case ACPI_TYPE_REGION:
 198                 case ACPI_TYPE_THERMAL:
 199                 case ACPI_TYPE_LOCAL_SCOPE:
 200
 201                         ACPI_ERROR((AE_INFO,
 202                                     "[%4.4s] Evaluation of object type [%s] is not supported",
 203                                     info->resolved_node->name.ascii,
 204                                     acpi_ut_get_type_name(info->resolved_node->
 205                                                           type)));
 206
 207                         return_ACPI_STATUS(AE_TYPE);
 208
 209                 default:
 210                         break;
 211                 }
 212
 213                 /*
 214                  * Objects require additional resolution steps (e.g., the Node may be
 215                  * a field that must be read, etc.) -- we can't just grab the object
 216                  * out of the node.
 217                  *
 218                  * Use resolve_node_to_value() to get the associated value.
 219                  *
 220                  * NOTE: we can get away with passing in NULL for a walk state because
 221                  * resolved_node is guaranteed to not be a reference to either a method
 222                  * local or a method argument (because this interface is never called
 223                  * from a running method.)
 224                  *
 225                  * Even though we do not directly invoke the interpreter for object
 226                  * resolution, we must lock it because we could access an opregion.
 227                  * The opregion access code assumes that the interpreter is locked.
 228                  */
 229                 acpi_ex_enter_interpreter();
 230
 231                 /* Function has a strange interface */
 232
 233                 status =
 234                     acpi_ex_resolve_node_to_value(&info->resolved_node, NULL);
 235                 acpi_ex_exit_interpreter();
 236
 237                 /*
 238                  * If acpi_ex_resolve_node_to_value() succeeded, the return value was placed
 239                  * in resolved_node.
 240                  */
 241                 if (ACPI_SUCCESS(status)) {
 242                         status = AE_CTRL_RETURN_VALUE;
 243                         info->return_object =
 244                             ACPI_CAST_PTR(union acpi_operand_object,
 245                                           info->resolved_node);
 246
 247                         ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
 248                                           "Returning object %p [%s]\n",
 249                                           info->return_object,
 250                                           acpi_ut_get_object_type_name(info->
 251                                                                        return_object)));
 252                 }
 253         }
 254
 255         /*
 256          * Check input argument count against the ASL-defined count for a method.
 257          * Also check predefined names: argument count and return value against
 258          * the ACPI specification. Some incorrect return value types are repaired.
 259          */
 260         (void)acpi_ns_check_predefined_names(node, info->param_count,
 261                 status, &info->return_object);
 262
 263         /* Check if there is a return value that must be dealt with */
 264
 265         if (status == AE_CTRL_RETURN_VALUE) {
 266
 267                 /* If caller does not want the return value, delete it */
 268
 269                 if (info->flags & ACPI_IGNORE_RETURN_VALUE) {
 270                         acpi_ut_remove_reference(info->return_object);
 271                         info->return_object = NULL;
 272                 }
 273
 274                 /* Map AE_CTRL_RETURN_VALUE to AE_OK, we are done with it */
 275
 276                 status = AE_OK;
 277         }
 278
 279         ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
 280                           "*** Completed evaluation of object %s ***\n",
 281                           info->pathname));
 282
 283         /*
 284          * Namespace was unlocked by the handling acpi_ns* function, so we
 285          * just return
 286          */
 287         return_ACPI_STATUS(status);
 288 }
 289
 290 /*******************************************************************************
 291  *
 292  * FUNCTION:    acpi_ns_exec_module_code_list
 293  *
 294  * PARAMETERS:  None
 295  *
 296  * RETURN:      None. Exceptions during method execution are ignored, since
 297  *              we cannot abort a table load.
 298  *
 299  * DESCRIPTION: Execute all elements of the global module-level code list.
 300  *              Each element is executed as a single control method.
 301  *
 302  ******************************************************************************/
 303
 304 void acpi_ns_exec_module_code_list(void)
 305 {
 306         union acpi_operand_object *prev;
 307         union acpi_operand_object *next;
 308         struct acpi_evaluate_info *info;
 309         u32 method_count = 0;
 310
 311         ACPI_FUNCTION_TRACE(ns_exec_module_code_list);
 312
 313         /* Exit now if the list is empty */
 314
 315         next = acpi_gbl_module_code_list;
 316         if (!next) {
 317                 return_VOID;
 318         }
 319
 320         /* Allocate the evaluation information block */
 321
 322         info = ACPI_ALLOCATE(sizeof(struct acpi_evaluate_info));
 323         if (!info) {
 324                 return_VOID;
 325         }
 326
 327         /* Walk the list, executing each "method" */
 328
 329         while (next) {
 330                 prev = next;
 331                 next = next->method.mutex;
 332
 333                 /* Clear the link field and execute the method */
 334
 335                 prev->method.mutex = NULL;
 336                 acpi_ns_exec_module_code(prev, info);
 337                 method_count++;
 338
 339                 /* Delete the (temporary) method object */
 340
 341                 acpi_ut_remove_reference(prev);
 342         }
 343
 344         ACPI_INFO((AE_INFO,
 345                    "Executed %u blocks of module-level executable AML code",
 346                    method_count));
 347
 348         ACPI_FREE(info);
 349         acpi_gbl_module_code_list = NULL;
 350         return_VOID;
 351 }
 352
 353 /*******************************************************************************
 354  *
 355  * FUNCTION:    acpi_ns_exec_module_code
 356  *
 357  * PARAMETERS:  method_obj          - Object container for the module-level code
 358  *              info                - Info block for method evaluation
 359  *
 360  * RETURN:      None. Exceptions during method execution are ignored, since
 361  *              we cannot abort a table load.
 362  *
 363  * DESCRIPTION: Execute a control method containing a block of module-level
 364  *              executable AML code. The control method is temporarily
 365  *              installed to the root node, then evaluated.
 366  *
 367  ******************************************************************************/
 368
 369 static void
 370 acpi_ns_exec_module_code(union acpi_operand_object *method_obj,
 371                          struct acpi_evaluate_info *info)
 372 {
 373         union acpi_operand_object *parent_obj;
 374         struct acpi_namespace_node *parent_node;
 375         acpi_object_type type;
 376         acpi_status status;
 377
 378         ACPI_FUNCTION_TRACE(ns_exec_module_code);
 379
 380         /*
 381          * Get the parent node. We cheat by using the next_object field
 382          * of the method object descriptor.
 383          */
 384         parent_node = ACPI_CAST_PTR(struct acpi_namespace_node,
 385                                     method_obj->method.next_object);
 386         type = acpi_ns_get_type(parent_node);
 387
 388         /*
 389          * Get the region handler and save it in the method object. We may need
 390          * this if an operation region declaration causes a _REG method to be run.
 391          *
 392          * We can't do this in acpi_ps_link_module_code because
 393          * acpi_gbl_root_node->Object is NULL at PASS1.
 394          */
 395         if ((type == ACPI_TYPE_DEVICE) && parent_node->object) {
 396                 method_obj->method.dispatch.handler =
 397                     parent_node->object->device.handler;
 398         }
 399
 400         /* Must clear next_object (acpi_ns_attach_object needs the field) */
 401
 402         method_obj->method.next_object = NULL;
 403
 404         /* Initialize the evaluation information block */
 405
 406         ACPI_MEMSET(info, 0, sizeof(struct acpi_evaluate_info));
 407         info->prefix_node = parent_node;
 408
 409         /*
 410          * Get the currently attached parent object. Add a reference, because the
 411          * ref count will be decreased when the method object is installed to
 412          * the parent node.
 413          */
 414         parent_obj = acpi_ns_get_attached_object(parent_node);
 415         if (parent_obj) {
 416                 acpi_ut_add_reference(parent_obj);
 417         }
 418
 419         /* Install the method (module-level code) in the parent node */
 420
 421         status = acpi_ns_attach_object(parent_node, method_obj,
 422                                        ACPI_TYPE_METHOD);
 423         if (ACPI_FAILURE(status)) {
 424                 goto exit;
 425         }
 426
 427         /* Execute the parent node as a control method */
 428
 429         status = acpi_ns_evaluate(info);
 430
 431         ACPI_DEBUG_PRINT((ACPI_DB_INIT, "Executed module-level code at %p\n",
 432                           method_obj->method.aml_start));
 433
 434         /* Delete a possible implicit return value (in slack mode) */
 435
 436         if (info->return_object) {
 437                 acpi_ut_remove_reference(info->return_object);
 438         }
 439
 440         /* Detach the temporary method object */
 441
 442         acpi_ns_detach_object(parent_node);
 443
 444         /* Restore the original parent object */
 445
 446         if (parent_obj) {
 447                 status = acpi_ns_attach_object(parent_node, parent_obj, type);
 448         } else {
 449                 parent_node->type = (u8)type;
 450         }
 451
 452       exit:
 453         if (parent_obj) {
 454                 acpi_ut_remove_reference(parent_obj);
 455         }
 456         return_VOID;
 457 }