drivers/acpi/namespace/nseval.c

   1 /*******************************************************************************
   2  *
   3  * Module Name: nseval - Object evaluation, includes control method execution
   4  *
   5  ******************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2008, 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 <acpi/acparser.h>
  46 #include <acpi/acinterp.h>
  47 #include <acpi/acnamesp.h>
  48
  49 #define _COMPONENT          ACPI_NAMESPACE
  50 ACPI_MODULE_NAME("nseval")
  51
  52 /*******************************************************************************
  53  *
  54  * FUNCTION:    acpi_ns_evaluate
  55  *
  56  * PARAMETERS:  Info            - Evaluation info block, contains:
  57  *                  prefix_node     - Prefix or Method/Object Node to execute
  58  *                  Pathname        - Name of method to execute, If NULL, the
  59  *                                    Node is the object to execute
  60  *                  Parameters      - List of parameters to pass to the method,
  61  *                                    terminated by NULL. Params itself may be
  62  *                                    NULL if no parameters are being passed.
  63  *                  return_object   - Where to put method's return value (if
  64  *                                    any). If NULL, no value is returned.
  65  *                  parameter_type  - Type of Parameter list
  66  *                  return_object   - Where to put method's return value (if
  67  *                                    any). If NULL, no value is returned.
  68  *                  Flags           - ACPI_IGNORE_RETURN_VALUE to delete return
  69  *
  70  * RETURN:      Status
  71  *
  72  * DESCRIPTION: Execute a control method or return the current value of an
  73  *              ACPI namespace object.
  74  *
  75  * MUTEX:       Locks interpreter
  76  *
  77  ******************************************************************************/
  78 acpi_status acpi_ns_evaluate(struct acpi_evaluate_info * info)
  79 {
  80         acpi_status status;
  81         struct acpi_namespace_node *node;
  82
  83         ACPI_FUNCTION_TRACE(ns_evaluate);
  84
  85         if (!info) {
  86                 return_ACPI_STATUS(AE_BAD_PARAMETER);
  87         }
  88
  89         /* Initialize the return value to an invalid object */
  90
  91         info->return_object = NULL;
  92
  93         /*
  94          * Get the actual namespace node for the target object. Handles these cases:
  95          *
  96          * 1) Null node, Pathname (absolute path)
  97          * 2) Node, Pathname (path relative to Node)
  98          * 3) Node, Null Pathname
  99          */
 100         status = acpi_ns_get_node(info->prefix_node, info->pathname,
 101                                   ACPI_NS_NO_UPSEARCH, &info->resolved_node);
 102         if (ACPI_FAILURE(status)) {
 103                 return_ACPI_STATUS(status);
 104         }
 105
 106         /*
 107          * For a method alias, we must grab the actual method node so that proper
 108          * scoping context will be established before execution.
 109          */
 110         if (acpi_ns_get_type(info->resolved_node) ==
 111             ACPI_TYPE_LOCAL_METHOD_ALIAS) {
 112                 info->resolved_node =
 113                     ACPI_CAST_PTR(struct acpi_namespace_node,
 114                                   info->resolved_node->object);
 115         }
 116
 117         ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "%s [%p] Value %p\n", info->pathname,
 118                           info->resolved_node,
 119                           acpi_ns_get_attached_object(info->resolved_node)));
 120
 121         node = info->resolved_node;
 122
 123         /*
 124          * Two major cases here:
 125          *
 126          * 1) The object is a control method -- execute it
 127          * 2) The object is not a method -- just return it's current value
 128          */
 129         if (acpi_ns_get_type(info->resolved_node) == ACPI_TYPE_METHOD) {
 130                 /*
 131                  * 1) Object is a control method - execute it
 132                  */
 133
 134                 /* Verify that there is a method object associated with this node */
 135
 136                 info->obj_desc =
 137                     acpi_ns_get_attached_object(info->resolved_node);
 138                 if (!info->obj_desc) {
 139                         ACPI_ERROR((AE_INFO,
 140                                     "Control method has no attached sub-object"));
 141                         return_ACPI_STATUS(AE_NULL_OBJECT);
 142                 }
 143
 144                 /*
 145                  * Calculate the number of arguments being passed to the method
 146                  */
 147
 148                 info->param_count = 0;
 149                 if (info->parameters) {
 150                         while (info->parameters[info->param_count])
 151                                 info->param_count++;
 152                 }
 153
 154                 /*
 155                  * Warning if too few or too many arguments have been passed by the
 156                  * caller. We don't want to abort here with an error because an
 157                  * incorrect number of arguments may not cause the method to fail.
 158                  * However, the method will fail if there are too few arguments passed
 159                  * and the method attempts to use one of the missing ones.
 160                  */
 161
 162                 if (info->param_count < info->obj_desc->method.param_count) {
 163                         ACPI_WARNING((AE_INFO,
 164                                     "Insufficient arguments - "
 165                                     "method [%4.4s] needs %d, found %d",
 166                                     acpi_ut_get_node_name(info->resolved_node),
 167                                     info->obj_desc->method.param_count,
 168                                     info->param_count));
 169                 } else if (info->param_count >
 170                                 info->obj_desc->method.param_count) {
 171                         ACPI_WARNING((AE_INFO,
 172                                       "Excess arguments - "
 173                                       "method [%4.4s] needs %d, found %d",
 174                                       acpi_ut_get_node_name(info->
 175                                                             resolved_node),
 176                                       info->obj_desc->method.param_count,
 177                                       info->param_count));
 178                 }
 179
 180                 ACPI_DUMP_PATHNAME(info->resolved_node, "Execute Method:",
 181                                    ACPI_LV_INFO, _COMPONENT);
 182
 183                 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
 184                                   "Method at AML address %p Length %X\n",
 185                                   info->obj_desc->method.aml_start + 1,
 186                                   info->obj_desc->method.aml_length - 1));
 187
 188                 /*
 189                  * Any namespace deletion must acquire both the namespace and
 190                  * interpreter locks to ensure that no thread is using the portion of
 191                  * the namespace that is being deleted.
 192                  *
 193                  * Execute the method via the interpreter. The interpreter is locked
 194                  * here before calling into the AML parser
 195                  */
 196                 acpi_ex_enter_interpreter();
 197                 status = acpi_ps_execute_method(info);
 198                 acpi_ex_exit_interpreter();
 199         } else {
 200                 /*
 201                  * 2) Object is not a method, return its current value
 202                  *
 203                  * Disallow certain object types. For these, "evaluation" is undefined.
 204                  */
 205                 switch (info->resolved_node->type) {
 206                 case ACPI_TYPE_DEVICE:
 207                 case ACPI_TYPE_EVENT:
 208                 case ACPI_TYPE_MUTEX:
 209                 case ACPI_TYPE_REGION:
 210                 case ACPI_TYPE_THERMAL:
 211                 case ACPI_TYPE_LOCAL_SCOPE:
 212
 213                         ACPI_ERROR((AE_INFO,
 214                                     "[%4.4s] Evaluation of object type [%s] is not supported",
 215                                     info->resolved_node->name.ascii,
 216                                     acpi_ut_get_type_name(info->resolved_node->
 217                                                           type)));
 218
 219                         return_ACPI_STATUS(AE_TYPE);
 220
 221                 default:
 222                         break;
 223                 }
 224
 225                 /*
 226                  * Objects require additional resolution steps (e.g., the Node may be
 227                  * a field that must be read, etc.) -- we can't just grab the object
 228                  * out of the node.
 229                  *
 230                  * Use resolve_node_to_value() to get the associated value.
 231                  *
 232                  * NOTE: we can get away with passing in NULL for a walk state because
 233                  * resolved_node is guaranteed to not be a reference to either a method
 234                  * local or a method argument (because this interface is never called
 235                  * from a running method.)
 236                  *
 237                  * Even though we do not directly invoke the interpreter for object
 238                  * resolution, we must lock it because we could access an opregion.
 239                  * The opregion access code assumes that the interpreter is locked.
 240                  */
 241                 acpi_ex_enter_interpreter();
 242
 243                 /* Function has a strange interface */
 244
 245                 status =
 246                     acpi_ex_resolve_node_to_value(&info->resolved_node, NULL);
 247                 acpi_ex_exit_interpreter();
 248
 249                 /*
 250                  * If acpi_ex_resolve_node_to_value() succeeded, the return value was placed
 251                  * in resolved_node.
 252                  */
 253                 if (ACPI_SUCCESS(status)) {
 254                         status = AE_CTRL_RETURN_VALUE;
 255                         info->return_object =
 256                             ACPI_CAST_PTR(union acpi_operand_object,
 257                                           info->resolved_node);
 258
 259                         ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
 260                                           "Returning object %p [%s]\n",
 261                                           info->return_object,
 262                                           acpi_ut_get_object_type_name(info->
 263                                                                        return_object)));
 264                 }
 265         }
 266
 267         /* Validation of return values for ACPI-predefined methods and objects */
 268
 269         if ((status == AE_OK) || (status == AE_CTRL_RETURN_VALUE)) {
 270                 /*
 271                  * If this is the first evaluation, check the return value. This
 272                  * ensures that any warnings will only be emitted during the very
 273                  * first evaluation of the object.
 274                  */
 275                 if (!(node->flags & ANOBJ_EVALUATED)) {
 276                         /*
 277                          * Check for a predefined ACPI name. If found, validate the
 278                          * returned object.
 279                          *
 280                          * Note: Ignore return status for now, emit warnings if there are
 281                          * problems with the returned object. May change later to abort
 282                          * the method on invalid return object.
 283                          */
 284                         (void)acpi_ns_check_predefined_names(node,
 285                              &info->return_object);
 286                 }
 287
 288                 /* Mark the node as having been evaluated */
 289
 290                 node->flags |= ANOBJ_EVALUATED;
 291         }
 292
 293         /* Check if there is a return value that must be dealt with */
 294
 295         if (status == AE_CTRL_RETURN_VALUE) {
 296
 297                 /* If caller does not want the return value, delete it */
 298
 299                 if (info->flags & ACPI_IGNORE_RETURN_VALUE) {
 300                         acpi_ut_remove_reference(info->return_object);
 301                         info->return_object = NULL;
 302                 }
 303
 304                 /* Map AE_CTRL_RETURN_VALUE to AE_OK, we are done with it */
 305
 306                 status = AE_OK;
 307         }
 308
 309         ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
 310                           "*** Completed evaluation of object %s ***\n",
 311                           info->pathname));
 312
 313         /*
 314          * Namespace was unlocked by the handling acpi_ns* function, so we
 315          * just return
 316          */
 317         return_ACPI_STATUS(status);
 318 }