Logo Search packages:      
Sourcecode: linux version File versions  Download package

nsaccess.c

/*******************************************************************************
 *
 * Module Name: nsaccess - Top-level functions for accessing ACPI namespace
 *
 ******************************************************************************/

/*
 * Copyright (C) 2000 - 2007, R. Byron Moore
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 */

#include <acpi/acpi.h>
#include <acpi/amlcode.h>
#include <acpi/acnamesp.h>
#include <acpi/acdispat.h>

#define _COMPONENT          ACPI_NAMESPACE
ACPI_MODULE_NAME("nsaccess")

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_root_initialize
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Allocate and initialize the default root named objects
 *
 * MUTEX:       Locks namespace for entire execution
 *
 ******************************************************************************/
acpi_status acpi_ns_root_initialize(void)
{
      acpi_status status;
      const struct acpi_predefined_names *init_val = NULL;
      struct acpi_namespace_node *new_node;
      union acpi_operand_object *obj_desc;
      acpi_string val = NULL;

      ACPI_FUNCTION_TRACE(ns_root_initialize);

      status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
      if (ACPI_FAILURE(status)) {
            return_ACPI_STATUS(status);
      }

      /*
       * The global root ptr is initially NULL, so a non-NULL value indicates
       * that acpi_ns_root_initialize() has already been called; just return.
       */
      if (acpi_gbl_root_node) {
            status = AE_OK;
            goto unlock_and_exit;
      }

      /*
       * Tell the rest of the subsystem that the root is initialized
       * (This is OK because the namespace is locked)
       */
      acpi_gbl_root_node = &acpi_gbl_root_node_struct;

      /* Enter the pre-defined names in the name table */

      ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                    "Entering predefined entries into namespace\n"));

      for (init_val = acpi_gbl_pre_defined_names; init_val->name; init_val++) {

            /* _OSI is optional for now, will be permanent later */

            if (!ACPI_STRCMP(init_val->name, "_OSI")
                && !acpi_gbl_create_osi_method) {
                  continue;
            }

            status = acpi_ns_lookup(NULL, init_val->name, init_val->type,
                              ACPI_IMODE_LOAD_PASS2,
                              ACPI_NS_NO_UPSEARCH, NULL, &new_node);

            if (ACPI_FAILURE(status) || (!new_node)) {      /* Must be on same line for code converter */
                  ACPI_EXCEPTION((AE_INFO, status,
                              "Could not create predefined name %s",
                              init_val->name));
            }

            /*
             * Name entered successfully.
             * If entry in pre_defined_names[] specifies an
             * initial value, create the initial value.
             */
            if (init_val->val) {
                  status = acpi_os_predefined_override(init_val, &val);
                  if (ACPI_FAILURE(status)) {
                        ACPI_ERROR((AE_INFO,
                                  "Could not override predefined %s",
                                  init_val->name));
                  }

                  if (!val) {
                        val = init_val->val;
                  }

                  /*
                   * Entry requests an initial value, allocate a
                   * descriptor for it.
                   */
                  obj_desc =
                      acpi_ut_create_internal_object(init_val->type);
                  if (!obj_desc) {
                        status = AE_NO_MEMORY;
                        goto unlock_and_exit;
                  }

                  /*
                   * Convert value string from table entry to
                   * internal representation. Only types actually
                   * used for initial values are implemented here.
                   */
                  switch (init_val->type) {
                  case ACPI_TYPE_METHOD:
                        obj_desc->method.param_count =
                            (u8) ACPI_TO_INTEGER(val);
                        obj_desc->common.flags |= AOPOBJ_DATA_VALID;

#if defined (ACPI_ASL_COMPILER)

                        /* Save the parameter count for the i_aSL compiler */

                        new_node->value = obj_desc->method.param_count;
#else
                        /* Mark this as a very SPECIAL method */

                        obj_desc->method.method_flags =
                            AML_METHOD_INTERNAL_ONLY;

#ifndef ACPI_DUMP_APP
                        obj_desc->method.implementation =
                            acpi_ut_osi_implementation;
#endif
#endif
                        break;

                  case ACPI_TYPE_INTEGER:

                        obj_desc->integer.value = ACPI_TO_INTEGER(val);
                        break;

                  case ACPI_TYPE_STRING:

                        /*
                         * Build an object around the static string
                         */
                        obj_desc->string.length =
                            (u32) ACPI_STRLEN(val);
                        obj_desc->string.pointer = val;
                        obj_desc->common.flags |= AOPOBJ_STATIC_POINTER;
                        break;

                  case ACPI_TYPE_MUTEX:

                        obj_desc->mutex.node = new_node;
                        obj_desc->mutex.sync_level =
                            (u8) (ACPI_TO_INTEGER(val) - 1);

                        /* Create a mutex */

                        status =
                            acpi_os_create_mutex(&obj_desc->mutex.
                                           os_mutex);
                        if (ACPI_FAILURE(status)) {
                              acpi_ut_remove_reference(obj_desc);
                              goto unlock_and_exit;
                        }

                        /* Special case for ACPI Global Lock */

                        if (ACPI_STRCMP(init_val->name, "_GL_") == 0) {
                              acpi_gbl_global_lock_mutex =
                                  obj_desc->mutex.os_mutex;

                              /* Create additional counting semaphore for global lock */

                              status =
                                  acpi_os_create_semaphore(1, 0,
                                                     &acpi_gbl_global_lock_semaphore);
                              if (ACPI_FAILURE(status)) {
                                    acpi_ut_remove_reference
                                        (obj_desc);
                                    goto unlock_and_exit;
                              }
                        }
                        break;

                  default:

                        ACPI_ERROR((AE_INFO,
                                  "Unsupported initial type value %X",
                                  init_val->type));
                        acpi_ut_remove_reference(obj_desc);
                        obj_desc = NULL;
                        continue;
                  }

                  /* Store pointer to value descriptor in the Node */

                  status = acpi_ns_attach_object(new_node, obj_desc,
                                           ACPI_GET_OBJECT_TYPE
                                           (obj_desc));

                  /* Remove local reference to the object */

                  acpi_ut_remove_reference(obj_desc);
            }
      }

      unlock_and_exit:
      (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);

      /* Save a handle to "_GPE", it is always present */

      if (ACPI_SUCCESS(status)) {
            status = acpi_ns_get_node(NULL, "\\_GPE", ACPI_NS_NO_UPSEARCH,
                                &acpi_gbl_fadt_gpe_device);
      }

      return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_lookup
 *
 * PARAMETERS:  scope_info      - Current scope info block
 *              Pathname        - Search pathname, in internal format
 *                                (as represented in the AML stream)
 *              Type            - Type associated with name
 *              interpreter_mode - IMODE_LOAD_PASS2 => add name if not found
 *              Flags           - Flags describing the search restrictions
 *              walk_state      - Current state of the walk
 *              return_node     - Where the Node is placed (if found
 *                                or created successfully)
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Find or enter the passed name in the name space.
 *              Log an error if name not found in Exec mode.
 *
 * MUTEX:       Assumes namespace is locked.
 *
 ******************************************************************************/

acpi_status
acpi_ns_lookup(union acpi_generic_state *scope_info,
             char *pathname,
             acpi_object_type type,
             acpi_interpreter_mode interpreter_mode,
             u32 flags,
             struct acpi_walk_state *walk_state,
             struct acpi_namespace_node **return_node)
{
      acpi_status status;
      char *path = pathname;
      struct acpi_namespace_node *prefix_node;
      struct acpi_namespace_node *current_node = NULL;
      struct acpi_namespace_node *this_node = NULL;
      u32 num_segments;
      u32 num_carats;
      acpi_name simple_name;
      acpi_object_type type_to_check_for;
      acpi_object_type this_search_type;
      u32 search_parent_flag = ACPI_NS_SEARCH_PARENT;
      u32 local_flags;

      ACPI_FUNCTION_TRACE(ns_lookup);

      if (!return_node) {
            return_ACPI_STATUS(AE_BAD_PARAMETER);
      }

      local_flags = flags & ~(ACPI_NS_ERROR_IF_FOUND | ACPI_NS_SEARCH_PARENT);
      *return_node = ACPI_ENTRY_NOT_FOUND;
      acpi_gbl_ns_lookup_count++;

      if (!acpi_gbl_root_node) {
            return_ACPI_STATUS(AE_NO_NAMESPACE);
      }

      /*
       * Get the prefix scope.
       * A null scope means use the root scope
       */
      if ((!scope_info) || (!scope_info->scope.node)) {
            ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
                          "Null scope prefix, using root node (%p)\n",
                          acpi_gbl_root_node));

            prefix_node = acpi_gbl_root_node;
      } else {
            prefix_node = scope_info->scope.node;
            if (ACPI_GET_DESCRIPTOR_TYPE(prefix_node) !=
                ACPI_DESC_TYPE_NAMED) {
                  ACPI_ERROR((AE_INFO, "%p is not a namespace node [%s]",
                            prefix_node,
                            acpi_ut_get_descriptor_name(prefix_node)));
                  return_ACPI_STATUS(AE_AML_INTERNAL);
            }

            if (!(flags & ACPI_NS_PREFIX_IS_SCOPE)) {
                  /*
                   * This node might not be a actual "scope" node (such as a
                   * Device/Method, etc.)  It could be a Package or other object node.
                   * Backup up the tree to find the containing scope node.
                   */
                  while (!acpi_ns_opens_scope(prefix_node->type) &&
                         prefix_node->type != ACPI_TYPE_ANY) {
                        prefix_node =
                            acpi_ns_get_parent_node(prefix_node);
                  }
            }
      }

      /* Save type   TBD: may be no longer necessary */

      type_to_check_for = type;

      /*
       * Begin examination of the actual pathname
       */
      if (!pathname) {

            /* A Null name_path is allowed and refers to the root */

            num_segments = 0;
            this_node = acpi_gbl_root_node;
            path = "";

            ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
                          "Null Pathname (Zero segments), Flags=%X\n",
                          flags));
      } else {
            /*
             * Name pointer is valid (and must be in internal name format)
             *
             * Check for scope prefixes:
             *
             * As represented in the AML stream, a namepath consists of an
             * optional scope prefix followed by a name segment part.
             *
             * If present, the scope prefix is either a Root Prefix (in
             * which case the name is fully qualified), or one or more
             * Parent Prefixes (in which case the name's scope is relative
             * to the current scope).
             */
            if (*path == (u8) AML_ROOT_PREFIX) {

                  /* Pathname is fully qualified, start from the root */

                  this_node = acpi_gbl_root_node;
                  search_parent_flag = ACPI_NS_NO_UPSEARCH;

                  /* Point to name segment part */

                  path++;

                  ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
                                "Path is absolute from root [%p]\n",
                                this_node));
            } else {
                  /* Pathname is relative to current scope, start there */

                  ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
                                "Searching relative to prefix scope [%4.4s] (%p)\n",
                                acpi_ut_get_node_name(prefix_node),
                                prefix_node));

                  /*
                   * Handle multiple Parent Prefixes (carat) by just getting
                   * the parent node for each prefix instance.
                   */
                  this_node = prefix_node;
                  num_carats = 0;
                  while (*path == (u8) AML_PARENT_PREFIX) {

                        /* Name is fully qualified, no search rules apply */

                        search_parent_flag = ACPI_NS_NO_UPSEARCH;
                        /*
                         * Point past this prefix to the name segment
                         * part or the next Parent Prefix
                         */
                        path++;

                        /* Backup to the parent node */

                        num_carats++;
                        this_node = acpi_ns_get_parent_node(this_node);
                        if (!this_node) {

                              /* Current scope has no parent scope */

                              ACPI_ERROR((AE_INFO,
                                        "ACPI path has too many parent prefixes (^) - reached beyond root node"));
                              return_ACPI_STATUS(AE_NOT_FOUND);
                        }
                  }

                  if (search_parent_flag == ACPI_NS_NO_UPSEARCH) {
                        ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
                                      "Search scope is [%4.4s], path has %d carat(s)\n",
                                      acpi_ut_get_node_name
                                      (this_node), num_carats));
                  }
            }

            /*
             * Determine the number of ACPI name segments in this pathname.
             *
             * The segment part consists of either:
             *  - A Null name segment (0)
             *  - A dual_name_prefix followed by two 4-byte name segments
             *  - A multi_name_prefix followed by a byte indicating the
             *      number of segments and the segments themselves.
             *  - A single 4-byte name segment
             *
             * Examine the name prefix opcode, if any, to determine the number of
             * segments.
             */
            switch (*path) {
            case 0:
                  /*
                   * Null name after a root or parent prefixes. We already
                   * have the correct target node and there are no name segments.
                   */
                  num_segments = 0;
                  type = this_node->type;

                  ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
                                "Prefix-only Pathname (Zero name segments), Flags=%X\n",
                                flags));
                  break;

            case AML_DUAL_NAME_PREFIX:

                  /* More than one name_seg, search rules do not apply */

                  search_parent_flag = ACPI_NS_NO_UPSEARCH;

                  /* Two segments, point to first name segment */

                  num_segments = 2;
                  path++;

                  ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
                                "Dual Pathname (2 segments, Flags=%X)\n",
                                flags));
                  break;

            case AML_MULTI_NAME_PREFIX_OP:

                  /* More than one name_seg, search rules do not apply */

                  search_parent_flag = ACPI_NS_NO_UPSEARCH;

                  /* Extract segment count, point to first name segment */

                  path++;
                  num_segments = (u32) (u8) * path;
                  path++;

                  ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
                                "Multi Pathname (%d Segments, Flags=%X)\n",
                                num_segments, flags));
                  break;

            default:
                  /*
                   * Not a Null name, no Dual or Multi prefix, hence there is
                   * only one name segment and Pathname is already pointing to it.
                   */
                  num_segments = 1;

                  ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
                                "Simple Pathname (1 segment, Flags=%X)\n",
                                flags));
                  break;
            }

            ACPI_DEBUG_EXEC(acpi_ns_print_pathname(num_segments, path));
      }

      /*
       * Search namespace for each segment of the name.  Loop through and
       * verify (or add to the namespace) each name segment.
       *
       * The object type is significant only at the last name
       * segment.  (We don't care about the types along the path, only
       * the type of the final target object.)
       */
      this_search_type = ACPI_TYPE_ANY;
      current_node = this_node;
      while (num_segments && current_node) {
            num_segments--;
            if (!num_segments) {
                  /*
                   * This is the last segment, enable typechecking
                   */
                  this_search_type = type;

                  /*
                   * Only allow automatic parent search (search rules) if the caller
                   * requested it AND we have a single, non-fully-qualified name_seg
                   */
                  if ((search_parent_flag != ACPI_NS_NO_UPSEARCH) &&
                      (flags & ACPI_NS_SEARCH_PARENT)) {
                        local_flags |= ACPI_NS_SEARCH_PARENT;
                  }

                  /* Set error flag according to caller */

                  if (flags & ACPI_NS_ERROR_IF_FOUND) {
                        local_flags |= ACPI_NS_ERROR_IF_FOUND;
                  }
            }

            /* Extract one ACPI name from the front of the pathname */

            ACPI_MOVE_32_TO_32(&simple_name, path);

            /* Try to find the single (4 character) ACPI name */

            status =
                acpi_ns_search_and_enter(simple_name, walk_state,
                                   current_node, interpreter_mode,
                                   this_search_type, local_flags,
                                   &this_node);
            if (ACPI_FAILURE(status)) {
                  if (status == AE_NOT_FOUND) {

                        /* Name not found in ACPI namespace */

                        ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
                                      "Name [%4.4s] not found in scope [%4.4s] %p\n",
                                      (char *)&simple_name,
                                      (char *)&current_node->name,
                                      current_node));
                  }

                  *return_node = this_node;
                  return_ACPI_STATUS(status);
            }

            /*
             * Sanity typecheck of the target object:
             *
             * If 1) This is the last segment (num_segments == 0)
             *    2) And we are looking for a specific type
             *       (Not checking for TYPE_ANY)
             *    3) Which is not an alias
             *    4) Which is not a local type (TYPE_SCOPE)
             *    5) And the type of target object is known (not TYPE_ANY)
             *    6) And target object does not match what we are looking for
             *
             * Then we have a type mismatch.  Just warn and ignore it.
             */
            if ((num_segments == 0) &&
                (type_to_check_for != ACPI_TYPE_ANY) &&
                (type_to_check_for != ACPI_TYPE_LOCAL_ALIAS) &&
                (type_to_check_for != ACPI_TYPE_LOCAL_METHOD_ALIAS) &&
                (type_to_check_for != ACPI_TYPE_LOCAL_SCOPE) &&
                (this_node->type != ACPI_TYPE_ANY) &&
                (this_node->type != type_to_check_for)) {

                  /* Complain about a type mismatch */

                  ACPI_WARNING((AE_INFO,
                              "NsLookup: Type mismatch on %4.4s (%s), searching for (%s)",
                              ACPI_CAST_PTR(char, &simple_name),
                              acpi_ut_get_type_name(this_node->type),
                              acpi_ut_get_type_name
                              (type_to_check_for)));
            }

            /*
             * If this is the last name segment and we are not looking for a
             * specific type, but the type of found object is known, use that type
             * to see if it opens a scope.
             */
            if ((num_segments == 0) && (type == ACPI_TYPE_ANY)) {
                  type = this_node->type;
            }

            /* Point to next name segment and make this node current */

            path += ACPI_NAME_SIZE;
            current_node = this_node;
      }

      /*
       * Always check if we need to open a new scope
       */
      if (!(flags & ACPI_NS_DONT_OPEN_SCOPE) && (walk_state)) {
            /*
             * If entry is a type which opens a scope, push the new scope on the
             * scope stack.
             */
            if (acpi_ns_opens_scope(type)) {
                  status =
                      acpi_ds_scope_stack_push(this_node, type,
                                         walk_state);
                  if (ACPI_FAILURE(status)) {
                        return_ACPI_STATUS(status);
                  }
            }
      }

      *return_node = this_node;
      return_ACPI_STATUS(AE_OK);
}

Generated by  Doxygen 1.6.0   Back to index