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 - 2011, 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         /*
 102          * Get the actual namespace node for the target object. Handles these cases:
 103          *
 104          * 1) Null node, Pathname (absolute path)
 105          * 2) Node, Pathname (path relative to Node)
 106          * 3) Node, Null Pathname
 107          */
 108         status = acpi_ns_get_node(info->prefix_node, info->pathname,
 109                                   ACPI_NS_NO_UPSEARCH, &info->resolved_node);
 110         if (ACPI_FAILURE(status)) {
 111                 return_ACPI_STATUS(status);
 112         }
 113
 114         /*
 115          * For a method alias, we must grab the actual method node so that proper
 116          * scoping context will be established before execution.
 117          */
 118         if (acpi_ns_get_type(info->resolved_node) ==
 119             ACPI_TYPE_LOCAL_METHOD_ALIAS) {
 120                 info->resolved_node =
 121                     ACPI_CAST_PTR(struct acpi_namespace_node,
 122                                   info->resolved_node->object);
 123         }
 124
 125         ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "%s [%p] Value %p\n", info->pathname,
 126                           info->resolved_node,
 127                           acpi_ns_get_attached_object(info->resolved_node)));
 128
 129         node = info->resolved_node;
 130
 131         /*
 132          * Two major cases here:
 133          *
 134          * 1) The object is a control method -- execute it
 135          * 2) The object is not a method -- just return it's current value
 136          */
 137         if (acpi_ns_get_type(info->resolved_node) == ACPI_TYPE_METHOD) {
 138                 /*
 139                  * 1) Object is a control method - execute it
 140                  */
 141
 142                 /* Verify that there is a method object associated with this node */
 143
 144                 info->obj_desc =
 145                     acpi_ns_get_attached_object(info->resolved_node);
 146                 if (!info->obj_desc) {
 147                         ACPI_ERROR((AE_INFO,
 148                                     "Control method has no attached sub-object"));
 149                         return_ACPI_STATUS(AE_NULL_OBJECT);
 150                 }
 151
 152                 /* Count the number of arguments being passed to the method */
 153
 154                 if (info->parameters) {
 155                         while (info->parameters[info->param_count]) {
 156                                 if (info->param_count > ACPI_METHOD_MAX_ARG) {
 157                                         return_ACPI_STATUS(AE_LIMIT);
 158                                 }
 159                                 info->param_count++;
 160                         }
 161                 }
 162
 163
 164                 ACPI_DUMP_PATHNAME(info->resolved_node, "ACPI: Execute Method",
 165                                    ACPI_LV_INFO, _COMPONENT);
 166
 167                 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
 168                                   "Method at AML address %p Length %X\n",
 169                                   info->obj_desc->method.aml_start + 1,
 170                                   info->obj_desc->method.aml_length - 1));
 171
 172                 /*
 173                  * Any namespace deletion must acquire both the namespace and
 174                  * interpreter locks to ensure that no thread is using the portion of
 175                  * the namespace that is being deleted.
 176                  *
 177                  * Execute the method via the interpreter. The interpreter is locked
 178                  * here before calling into the AML parser
 179                  */
 180                 acpi_ex_enter_interpreter();
 181                 status = acpi_ps_execute_method(info);
 182                 acpi_ex_exit_interpreter();
 183         } else {
 184                 /*
 185                  * 2) Object is not a method, return its current value
 186                  *
 187                  * Disallow certain object types. For these, "evaluation" is undefined.
 188                  */
 189                 switch (info->resolved_node->type) {
 190                 case ACPI_TYPE_DEVICE:
 191                 case ACPI_TYPE_EVENT:
 192                 case ACPI_TYPE_MUTEX:
 193                 case ACPI_TYPE_REGION:
 194                 case ACPI_TYPE_THERMAL:
 195                 case ACPI_TYPE_LOCAL_SCOPE:
 196
 197                         ACPI_ERROR((AE_INFO,
 198                                     "[%4.4s] Evaluation of object type [%s] is not supported",
 199                                     info->resolved_node->name.ascii,
 200                                     acpi_ut_get_type_name(info->resolved_node->
 201                                                           type)));
 202
 203                         return_ACPI_STATUS(AE_TYPE);
 204
 205                 default:
 206                         break;
 207                 }
 208
 209                 /*
 210                  * Objects require additional resolution steps (e.g., the Node may be
 211                  * a field that must be read, etc.) -- we can't just grab the object
 212                  * out of the node.
 213                  *
 214                  * Use resolve_node_to_value() to get the associated value.
 215                  *
 216                  * NOTE: we can get away with passing in NULL for a walk state because
 217                  * resolved_node is guaranteed to not be a reference to either a method
 218                  * local or a method argument (because this interface is never called
 219                  * from a running method.)
 220                  *
 221                  * Even though we do not directly invoke the interpreter for object
 222                  * resolution, we must lock it because we could access an opregion.
 223                  * The opregion access code assumes that the interpreter is locked.
 224                  */
 225                 acpi_ex_enter_interpreter();
 226
 227                 /* Function has a strange interface */
 228
 229                 status =
 230                     acpi_ex_resolve_node_to_value(&info->resolved_node, NULL);
 231                 acpi_ex_exit_interpreter();
 232
 233                 /*
 234                  * If acpi_ex_resolve_node_to_value() succeeded, the return value was placed
 235                  * in resolved_node.
 236                  */
 237                 if (ACPI_SUCCESS(status)) {
 238                         status = AE_CTRL_RETURN_VALUE;
 239                         info->return_object =
 240                             ACPI_CAST_PTR(union acpi_operand_object,
 241                                           info->resolved_node);
 242
 243                         ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
 244                                           "Returning object %p [%s]\n",
 245                                           info->return_object,
 246                                           acpi_ut_get_object_type_name(info->
 247                                                                        return_object)));
 248                 }
 249         }
 250
 251         /*
 252          * Check input argument count against the ASL-defined count for a method.
 253          * Also check predefined names: argument count and return value against
 254          * the ACPI specification. Some incorrect return value types are repaired.
 255          */
 256         (void)acpi_ns_check_predefined_names(node, info->param_count,
 257                 status, &info->return_object);
 258
 259         /* Check if there is a return value that must be dealt with */
 260
 261         if (status == AE_CTRL_RETURN_VALUE) {
 262
 263                 /* If caller does not want the return value, delete it */
 264
 265                 if (info->flags & ACPI_IGNORE_RETURN_VALUE) {
 266                         acpi_ut_remove_reference(info->return_object);
 267                         info->return_object = NULL;
 268                 }
 269
 270                 /* Map AE_CTRL_RETURN_VALUE to AE_OK, we are done with it */
 271
 272                 status = AE_OK;
 273         }
 274
 275         ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
 276                           "*** Completed evaluation of object %s ***\n",
 277                           info->pathname));
 278
 279         /*
 280          * Namespace was unlocked by the handling acpi_ns* function, so we
 281          * just return
 282          */
 283         return_ACPI_STATUS(status);
 284 }
 285
 286 /*******************************************************************************
 287  *
 288  * FUNCTION:    acpi_ns_exec_module_code_list
 289  *
 290  * PARAMETERS:  None
 291  *
 292  * RETURN:      None. Exceptions during method execution are ignored, since
 293  *              we cannot abort a table load.
 294  *
 295  * DESCRIPTION: Execute all elements of the global module-level code list.
 296  *              Each element is executed as a single control method.
 297  *
 298  ******************************************************************************/
 299
 300 void acpi_ns_exec_module_code_list(void)
 301 {
 302         union acpi_operand_object *prev;
 303         union acpi_operand_object *next;
 304         struct acpi_evaluate_info *info;
 305         u32 method_count = 0;
 306
 307         ACPI_FUNCTION_TRACE(ns_exec_module_code_list);
 308
 309         /* Exit now if the list is empty */
 310
 311         next = acpi_gbl_module_code_list;
 312         if (!next) {
 313                 return_VOID;
 314         }
 315
 316         /* Allocate the evaluation information block */
 317
 318         info = ACPI_ALLOCATE(sizeof(struct acpi_evaluate_info));
 319         if (!info) {
 320                 return_VOID;
 321         }
 322
 323         /* Walk the list, executing each "method" */
 324
 325         while (next) {
 326                 prev = next;
 327                 next = next->method.mutex;
 328
 329                 /* Clear the link field and execute the method */
 330
 331                 prev->method.mutex = NULL;
 332                 acpi_ns_exec_module_code(prev, info);
 333                 method_count++;
 334
 335                 /* Delete the (temporary) method object */
 336
 337                 acpi_ut_remove_reference(prev);
 338         }
 339
 340         ACPI_INFO((AE_INFO,
 341                    "Executed %u blocks of module-level executable AML code",
 342                    method_count));
 343
 344         ACPI_FREE(info);
 345         acpi_gbl_module_code_list = NULL;
 346         return_VOID;
 347 }
 348
 349 /*******************************************************************************
 350  *
 351  * FUNCTION:    acpi_ns_exec_module_code
 352  *
 353  * PARAMETERS:  method_obj          - Object container for the module-level code
 354  *              Info                - Info block for method evaluation
 355  *
 356  * RETURN:      None. Exceptions during method execution are ignored, since
 357  *              we cannot abort a table load.
 358  *
 359  * DESCRIPTION: Execute a control method containing a block of module-level
 360  *              executable AML code. The control method is temporarily
 361  *              installed to the root node, then evaluated.
 362  *
 363  ******************************************************************************/
 364
 365 static void
 366 acpi_ns_exec_module_code(union acpi_operand_object *method_obj,
 367                          struct acpi_evaluate_info *info)
 368 {
 369         union acpi_operand_object *parent_obj;
 370         struct acpi_namespace_node *parent_node;
 371         acpi_object_type type;
 372         acpi_status status;
 373
 374         ACPI_FUNCTION_TRACE(ns_exec_module_code);
 375
 376         /*
 377          * Get the parent node. We cheat by using the next_object field
 378          * of the method object descriptor.
 379          */
 380         parent_node = ACPI_CAST_PTR(struct acpi_namespace_node,
 381                                     method_obj->method.next_object);
 382         type = acpi_ns_get_type(parent_node);
 383
 384         /*
 385          * Get the region handler and save it in the method object. We may need
 386          * this if an operation region declaration causes a _REG method to be run.
 387          *
 388          * We can't do this in acpi_ps_link_module_code because
 389          * acpi_gbl_root_node->Object is NULL at PASS1.
 390          */
 391         if ((type == ACPI_TYPE_DEVICE) && parent_node->object) {
 392                 method_obj->method.dispatch.handler =
 393                     parent_node->object->device.handler;
 394         }
 395
 396         /* Must clear next_object (acpi_ns_attach_object needs the field) */
 397
 398         method_obj->method.next_object = NULL;
 399
 400         /* Initialize the evaluation information block */
 401
 402         ACPI_MEMSET(info, 0, sizeof(struct acpi_evaluate_info));
 403         info->prefix_node = parent_node;
 404
 405         /*
 406          * Get the currently attached parent object. Add a reference, because the
 407          * ref count will be decreased when the method object is installed to
 408          * the parent node.
 409          */
 410         parent_obj = acpi_ns_get_attached_object(parent_node);
 411         if (parent_obj) {
 412                 acpi_ut_add_reference(parent_obj);
 413         }
 414
 415         /* Install the method (module-level code) in the parent node */
 416
 417         status = acpi_ns_attach_object(parent_node, method_obj,
 418                                        ACPI_TYPE_METHOD);
 419         if (ACPI_FAILURE(status)) {
 420                 goto exit;
 421         }
 422
 423         /* Execute the parent node as a control method */
 424
 425         status = acpi_ns_evaluate(info);
 426
 427         ACPI_DEBUG_PRINT((ACPI_DB_INIT, "Executed module-level code at %p\n",
 428                           method_obj->method.aml_start));
 429
 430         /* Delete a possible implicit return value (in slack mode) */
 431
 432         if (info->return_object) {
 433                 acpi_ut_remove_reference(info->return_object);
 434         }
 435
 436         /* Detach the temporary method object */
 437
 438         acpi_ns_detach_object(parent_node);
 439
 440         /* Restore the original parent object */
 441
 442         if (parent_obj) {
 443                 status = acpi_ns_attach_object(parent_node, parent_obj, type);
 444         } else {
 445                 parent_node->type = (u8)type;
 446         }
 447
 448       exit:
 449         if (parent_obj) {
 450                 acpi_ut_remove_reference(parent_obj);
 451         }
 452         return_VOID;
 453 }