linux/drivers/acpi/acpica/nsparse.c
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   1/******************************************************************************
   2 *
   3 * Module Name: nsparse - namespace interface to AML parser
   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 "acnamesp.h"
  47#include "acparser.h"
  48#include "acdispat.h"
  49#include "actables.h"
  50
  51#define _COMPONENT          ACPI_NAMESPACE
  52ACPI_MODULE_NAME("nsparse")
  53
  54/*******************************************************************************
  55 *
  56 * FUNCTION:    ns_one_complete_parse
  57 *
  58 * PARAMETERS:  pass_number             - 1 or 2
  59 *              table_desc              - The table to be parsed.
  60 *
  61 * RETURN:      Status
  62 *
  63 * DESCRIPTION: Perform one complete parse of an ACPI/AML table.
  64 *
  65 ******************************************************************************/
  66acpi_status
  67acpi_ns_one_complete_parse(u32 pass_number,
  68                           u32 table_index,
  69                           struct acpi_namespace_node *start_node)
  70{
  71        union acpi_parse_object *parse_root;
  72        acpi_status status;
  73       u32 aml_length;
  74        u8 *aml_start;
  75        struct acpi_walk_state *walk_state;
  76        struct acpi_table_header *table;
  77        acpi_owner_id owner_id;
  78
  79        ACPI_FUNCTION_TRACE(ns_one_complete_parse);
  80
  81        status = acpi_tb_get_owner_id(table_index, &owner_id);
  82        if (ACPI_FAILURE(status)) {
  83                return_ACPI_STATUS(status);
  84        }
  85
  86        /* Create and init a Root Node */
  87
  88        parse_root = acpi_ps_create_scope_op();
  89        if (!parse_root) {
  90                return_ACPI_STATUS(AE_NO_MEMORY);
  91        }
  92
  93        /* Create and initialize a new walk state */
  94
  95        walk_state = acpi_ds_create_walk_state(owner_id, NULL, NULL, NULL);
  96        if (!walk_state) {
  97                acpi_ps_free_op(parse_root);
  98                return_ACPI_STATUS(AE_NO_MEMORY);
  99        }
 100
 101        status = acpi_get_table_by_index(table_index, &table);
 102        if (ACPI_FAILURE(status)) {
 103                acpi_ds_delete_walk_state(walk_state);
 104                acpi_ps_free_op(parse_root);
 105                return_ACPI_STATUS(status);
 106        }
 107
 108        /* Table must consist of at least a complete header */
 109
 110        if (table->length < sizeof(struct acpi_table_header)) {
 111                status = AE_BAD_HEADER;
 112        } else {
 113                aml_start = (u8 *) table + sizeof(struct acpi_table_header);
 114                aml_length = table->length - sizeof(struct acpi_table_header);
 115                status = acpi_ds_init_aml_walk(walk_state, parse_root, NULL,
 116                                               aml_start, aml_length, NULL,
 117                                               (u8) pass_number);
 118        }
 119
 120        if (ACPI_FAILURE(status)) {
 121                acpi_ds_delete_walk_state(walk_state);
 122                goto cleanup;
 123        }
 124
 125        /* start_node is the default location to load the table */
 126
 127        if (start_node && start_node != acpi_gbl_root_node) {
 128                status =
 129                    acpi_ds_scope_stack_push(start_node, ACPI_TYPE_METHOD,
 130                                             walk_state);
 131                if (ACPI_FAILURE(status)) {
 132                        acpi_ds_delete_walk_state(walk_state);
 133                        goto cleanup;
 134                }
 135        }
 136
 137        /* Parse the AML */
 138
 139        ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "*PARSE* pass %u parse\n",
 140                          pass_number));
 141        status = acpi_ps_parse_aml(walk_state);
 142
 143      cleanup:
 144        acpi_ps_delete_parse_tree(parse_root);
 145        return_ACPI_STATUS(status);
 146}
 147
 148/*******************************************************************************
 149 *
 150 * FUNCTION:    acpi_ns_parse_table
 151 *
 152 * PARAMETERS:  table_desc      - An ACPI table descriptor for table to parse
 153 *              start_node      - Where to enter the table into the namespace
 154 *
 155 * RETURN:      Status
 156 *
 157 * DESCRIPTION: Parse AML within an ACPI table and return a tree of ops
 158 *
 159 ******************************************************************************/
 160
 161acpi_status
 162acpi_ns_parse_table(u32 table_index, struct acpi_namespace_node *start_node)
 163{
 164        acpi_status status;
 165
 166        ACPI_FUNCTION_TRACE(ns_parse_table);
 167
 168        /*
 169         * AML Parse, pass 1
 170         *
 171         * In this pass, we load most of the namespace.  Control methods
 172         * are not parsed until later.  A parse tree is not created.  Instead,
 173         * each Parser Op subtree is deleted when it is finished.  This saves
 174         * a great deal of memory, and allows a small cache of parse objects
 175         * to service the entire parse.  The second pass of the parse then
 176         * performs another complete parse of the AML.
 177         */
 178        ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "**** Start pass 1\n"));
 179        status = acpi_ns_one_complete_parse(ACPI_IMODE_LOAD_PASS1,
 180                                            table_index, start_node);
 181        if (ACPI_FAILURE(status)) {
 182                return_ACPI_STATUS(status);
 183        }
 184
 185        /*
 186         * AML Parse, pass 2
 187         *
 188         * In this pass, we resolve forward references and other things
 189         * that could not be completed during the first pass.
 190         * Another complete parse of the AML is performed, but the
 191         * overhead of this is compensated for by the fact that the
 192         * parse objects are all cached.
 193         */
 194        ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "**** Start pass 2\n"));
 195        status = acpi_ns_one_complete_parse(ACPI_IMODE_LOAD_PASS2,
 196                                            table_index, start_node);
 197        if (ACPI_FAILURE(status)) {
 198                return_ACPI_STATUS(status);
 199        }
 200
 201        return_ACPI_STATUS(status);
 202}
 203