LXR linux/drivers/acpi/acpica/nseval.c

   1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
   2/*******************************************************************************
   3 *
   4 * Module Name: nseval - Object evaluation, includes control method execution
   5 *
   6 ******************************************************************************/
   7
   8#include <acpi/acpi.h>
   9#include "accommon.h"
  10#include "acparser.h"
  11#include "acinterp.h"
  12#include "acnamesp.h"
  13
  14#define _COMPONENT          ACPI_NAMESPACE
  15ACPI_MODULE_NAME("nseval")
  16
  17/*******************************************************************************
  18 *
  19 * FUNCTION:    acpi_ns_evaluate
  20 *
  21 * PARAMETERS:  info            - Evaluation info block, contains these fields
  22 *                                and more:
  23 *                  prefix_node     - Prefix or Method/Object Node to execute
  24 *                  relative_path   - Name of method to execute, If NULL, the
  25 *                                    Node is the object to execute
  26 *                  parameters      - List of parameters to pass to the method,
  27 *                                    terminated by NULL. Params itself may be
  28 *                                    NULL if no parameters are being passed.
  29 *                  parameter_type  - Type of Parameter list
  30 *                  return_object   - Where to put method's return value (if
  31 *                                    any). If NULL, no value is returned.
  32 *                  flags           - ACPI_IGNORE_RETURN_VALUE to delete return
  33 *
  34 * RETURN:      Status
  35 *
  36 * DESCRIPTION: Execute a control method or return the current value of an
  37 *              ACPI namespace object.
  38 *
  39 * MUTEX:       Locks interpreter
  40 *
  41 ******************************************************************************/
  42acpi_status acpi_ns_evaluate(struct acpi_evaluate_info *info)
  43{
  44        acpi_status status;
  45
  46        ACPI_FUNCTION_TRACE(ns_evaluate);
  47
  48        if (!info) {
  49                return_ACPI_STATUS(AE_BAD_PARAMETER);
  50        }
  51
  52        if (!info->node) {
  53                /*
  54                 * Get the actual namespace node for the target object if we
  55                 * need to. Handles these cases:
  56                 *
  57                 * 1) Null node, valid pathname from root (absolute path)
  58                 * 2) Node and valid pathname (path relative to Node)
  59                 * 3) Node, Null pathname
  60                 */
  61                status =
  62                    acpi_ns_get_node(info->prefix_node, info->relative_pathname,
  63                                     ACPI_NS_NO_UPSEARCH, &info->node);
  64                if (ACPI_FAILURE(status)) {
  65                        return_ACPI_STATUS(status);
  66                }
  67        }
  68
  69        /*
  70         * For a method alias, we must grab the actual method node so that
  71         * proper scoping context will be established before execution.
  72         */
  73        if (acpi_ns_get_type(info->node) == ACPI_TYPE_LOCAL_METHOD_ALIAS) {
  74                info->node =
  75                    ACPI_CAST_PTR(struct acpi_namespace_node,
  76                                  info->node->object);
  77        }
  78
  79        /* Complete the info block initialization */
  80
  81        info->return_object = NULL;
  82        info->node_flags = info->node->flags;
  83        info->obj_desc = acpi_ns_get_attached_object(info->node);
  84
  85        ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "%s [%p] Value %p\n",
  86                          info->relative_pathname, info->node,
  87                          acpi_ns_get_attached_object(info->node)));
  88
  89        /* Get info if we have a predefined name (_HID, etc.) */
  90
  91        info->predefined =
  92            acpi_ut_match_predefined_method(info->node->name.ascii);
  93
  94        /* Get the full pathname to the object, for use in warning messages */
  95
  96        info->full_pathname = acpi_ns_get_normalized_pathname(info->node, TRUE);
  97        if (!info->full_pathname) {
  98                return_ACPI_STATUS(AE_NO_MEMORY);
  99        }
 100
 101        /* Optional object evaluation log */
 102
 103        ACPI_DEBUG_PRINT_RAW((ACPI_DB_EVALUATION,
 104                              "%-26s:  %s (%s)\n", "   Enter evaluation",
 105                              &info->full_pathname[1],
 106                              acpi_ut_get_type_name(info->node->type)));
 107
 108        /* Count the number of arguments being passed in */
 109
 110        info->param_count = 0;
 111        if (info->parameters) {
 112                while (info->parameters[info->param_count]) {
 113                        info->param_count++;
 114                }
 115
 116                /* Warn on impossible argument count */
 117
 118                if (info->param_count > ACPI_METHOD_NUM_ARGS) {
 119                        ACPI_WARN_PREDEFINED((AE_INFO, info->full_pathname,
 120                                              ACPI_WARN_ALWAYS,
 121                                              "Excess arguments (%u) - using only %u",
 122                                              info->param_count,
 123                                              ACPI_METHOD_NUM_ARGS));
 124
 125                        info->param_count = ACPI_METHOD_NUM_ARGS;
 126                }
 127        }
 128
 129        /*
 130         * For predefined names: Check that the declared argument count
 131         * matches the ACPI spec -- otherwise this is a BIOS error.
 132         */
 133        acpi_ns_check_acpi_compliance(info->full_pathname, info->node,
 134                                      info->predefined);
 135
 136        /*
 137         * For all names: Check that the incoming argument count for
 138         * this method/object matches the actual ASL/AML definition.
 139         */
 140        acpi_ns_check_argument_count(info->full_pathname, info->node,
 141                                     info->param_count, info->predefined);
 142
 143        /* For predefined names: Typecheck all incoming arguments */
 144
 145        acpi_ns_check_argument_types(info);
 146
 147        /*
 148         * Three major evaluation cases:
 149         *
 150         * 1) Object types that cannot be evaluated by definition
 151         * 2) The object is a control method -- execute it
 152         * 3) The object is not a method -- just return it's current value
 153         */
 154        switch (acpi_ns_get_type(info->node)) {
 155        case ACPI_TYPE_ANY:
 156        case ACPI_TYPE_DEVICE:
 157        case ACPI_TYPE_EVENT:
 158        case ACPI_TYPE_MUTEX:
 159        case ACPI_TYPE_REGION:
 160        case ACPI_TYPE_THERMAL:
 161        case ACPI_TYPE_LOCAL_SCOPE:
 162                /*
 163                 * 1) Disallow evaluation of these object types. For these,
 164                 *    object evaluation is undefined.
 165                 */
 166                ACPI_ERROR((AE_INFO,
 167                            "%s: This object type [%s] "
 168                            "never contains data and cannot be evaluated",
 169                            info->full_pathname,
 170                            acpi_ut_get_type_name(info->node->type)));
 171
 172                status = AE_TYPE;
 173                goto cleanup;
 174
 175        case ACPI_TYPE_METHOD:
 176                /*
 177                 * 2) Object is a control method - execute it
 178                 */
 179
 180                /* Verify that there is a method object associated with this node */
 181
 182                if (!info->obj_desc) {
 183                        ACPI_ERROR((AE_INFO,
 184                                    "%s: Method has no attached sub-object",
 185                                    info->full_pathname));
 186                        status = AE_NULL_OBJECT;
 187                        goto cleanup;
 188                }
 189
 190                ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
 191                                  "**** Execute method [%s] at AML address %p length %X\n",
 192                                  info->full_pathname,
 193                                  info->obj_desc->method.aml_start + 1,
 194                                  info->obj_desc->method.aml_length - 1));
 195
 196                /*
 197                 * Any namespace deletion must acquire both the namespace and
 198                 * interpreter locks to ensure that no thread is using the portion of
 199                 * the namespace that is being deleted.
 200                 *
 201                 * Execute the method via the interpreter. The interpreter is locked
 202                 * here before calling into the AML parser
 203                 */
 204                acpi_ex_enter_interpreter();
 205                status = acpi_ps_execute_method(info);
 206                acpi_ex_exit_interpreter();
 207                break;
 208
 209        default:
 210                /*
 211                 * 3) All other non-method objects -- get the current object value
 212                 */
 213
 214                /*
 215                 * Some objects require additional resolution steps (e.g., the Node
 216                 * may be a field that must be read, etc.) -- we can't just grab
 217                 * the object out of the node.
 218                 *
 219                 * Use resolve_node_to_value() to get the associated value.
 220                 *
 221                 * NOTE: we can get away with passing in NULL for a walk state because
 222                 * the Node is guaranteed to not be a reference to either a method
 223                 * local or a method argument (because this interface is never called
 224                 * from a running method.)
 225                 *
 226                 * Even though we do not directly invoke the interpreter for object
 227                 * resolution, we must lock it because we could access an op_region.
 228                 * The op_region access code assumes that the interpreter is locked.
 229                 */
 230                acpi_ex_enter_interpreter();
 231
 232                /* TBD: resolve_node_to_value has a strange interface, fix */
 233
 234                info->return_object =
 235                    ACPI_CAST_PTR(union acpi_operand_object, info->node);
 236
 237                status =
 238                    acpi_ex_resolve_node_to_value(ACPI_CAST_INDIRECT_PTR
 239                                                  (struct acpi_namespace_node,
 240                                                   &info->return_object), NULL);
 241                acpi_ex_exit_interpreter();
 242
 243                if (ACPI_FAILURE(status)) {
 244                        info->return_object = NULL;
 245                        goto cleanup;
 246                }
 247
 248                ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "Returned object %p [%s]\n",
 249                                  info->return_object,
 250                                  acpi_ut_get_object_type_name(info->
 251                                                               return_object)));
 252
 253                status = AE_CTRL_RETURN_VALUE;  /* Always has a "return value" */
 254                break;
 255        }
 256
 257        /*
 258         * For predefined names, check the return value against the ACPI
 259         * specification. Some incorrect return value types are repaired.
 260         */
 261        (void)acpi_ns_check_return_value(info->node, info, info->param_count,
 262                                         status, &info->return_object);
 263
 264        /* Check if there is a return value that must be dealt with */
 265
 266        if (status == AE_CTRL_RETURN_VALUE) {
 267
 268                /* If caller does not want the return value, delete it */
 269
 270                if (info->flags & ACPI_IGNORE_RETURN_VALUE) {
 271                        acpi_ut_remove_reference(info->return_object);
 272                        info->return_object = NULL;
 273                }
 274
 275                /* Map AE_CTRL_RETURN_VALUE to AE_OK, we are done with it */
 276
 277                status = AE_OK;
 278        } else if (ACPI_FAILURE(status)) {
 279
 280                /* If return_object exists, delete it */
 281
 282                if (info->return_object) {
 283                        acpi_ut_remove_reference(info->return_object);
 284                        info->return_object = NULL;
 285                }
 286        }
 287
 288        ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
 289                          "*** Completed evaluation of object %s ***\n",
 290                          info->relative_pathname));
 291
 292cleanup:
 293        /* Optional object evaluation log */
 294
 295        ACPI_DEBUG_PRINT_RAW((ACPI_DB_EVALUATION,
 296                              "%-26s:  %s\n", "   Exit evaluation",
 297                              &info->full_pathname[1]));
 298
 299        /*
 300         * Namespace was unlocked by the handling acpi_ns* function, so we
 301         * just free the pathname and return
 302         */
 303        ACPI_FREE(info->full_pathname);
 304        info->full_pathname = NULL;
 305        return_ACPI_STATUS(status);
 306}
 307