drivers/acpi/namespace/nsparse.c

   1 /******************************************************************************
   2  *
   3  * Module Name: nsparse - namespace interface to AML parser
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2007, R. Byron Moore
   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/acnamesp.h>
  46 #include <acpi/acparser.h>
  47 #include <acpi/acdispat.h>
  48 #include <acpi/actables.h>
  49
  50 #define _COMPONENT          ACPI_NAMESPACE
  51 ACPI_MODULE_NAME("nsparse")
  52
  53 /*******************************************************************************
  54  *
  55  * FUNCTION:    ns_one_complete_parse
  56  *
  57  * PARAMETERS:  pass_number             - 1 or 2
  58  *              table_desc              - The table to be parsed.
  59  *
  60  * RETURN:      Status
  61  *
  62  * DESCRIPTION: Perform one complete parse of an ACPI/AML table.
  63  *
  64  ******************************************************************************/
  65 acpi_status
  66 acpi_ns_one_complete_parse(acpi_native_uint pass_number,
  67                            acpi_native_uint table_index)
  68 {
  69         union acpi_parse_object *parse_root;
  70         acpi_status status;
  71         acpi_native_uint aml_length;
  72         u8 *aml_start;
  73         struct acpi_walk_state *walk_state;
  74         struct acpi_table_header *table;
  75         acpi_owner_id owner_id;
  76
  77         ACPI_FUNCTION_TRACE(ns_one_complete_parse);
  78
  79         status = acpi_tb_get_owner_id(table_index, &owner_id);
  80         if (ACPI_FAILURE(status)) {
  81                 return_ACPI_STATUS(status);
  82         }
  83
  84         /* Create and init a Root Node */
  85
  86         parse_root = acpi_ps_create_scope_op();
  87         if (!parse_root) {
  88                 return_ACPI_STATUS(AE_NO_MEMORY);
  89         }
  90
  91         /* Create and initialize a new walk state */
  92
  93         walk_state = acpi_ds_create_walk_state(owner_id, NULL, NULL, NULL);
  94         if (!walk_state) {
  95                 acpi_ps_free_op(parse_root);
  96                 return_ACPI_STATUS(AE_NO_MEMORY);
  97         }
  98
  99         status = acpi_get_table_by_index(table_index, &table);
 100         if (ACPI_FAILURE(status)) {
 101                 acpi_ds_delete_walk_state(walk_state);
 102                 acpi_ps_free_op(parse_root);
 103                 return_ACPI_STATUS(status);
 104         }
 105
 106         /* Table must consist of at least a complete header */
 107
 108         if (table->length < sizeof(struct acpi_table_header)) {
 109                 status = AE_BAD_HEADER;
 110         } else {
 111                 aml_start = (u8 *) table + sizeof(struct acpi_table_header);
 112                 aml_length = table->length - sizeof(struct acpi_table_header);
 113                 status = acpi_ds_init_aml_walk(walk_state, parse_root, NULL,
 114                                                aml_start, aml_length, NULL,
 115                                                (u8) pass_number);
 116         }
 117
 118         if (ACPI_FAILURE(status)) {
 119                 acpi_ds_delete_walk_state(walk_state);
 120                 acpi_ps_delete_parse_tree(parse_root);
 121                 return_ACPI_STATUS(status);
 122         }
 123
 124         /* Parse the AML */
 125
 126         ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "*PARSE* pass %d parse\n",
 127                           (unsigned)pass_number));
 128         status = acpi_ps_parse_aml(walk_state);
 129
 130         acpi_ps_delete_parse_tree(parse_root);
 131         return_ACPI_STATUS(status);
 132 }
 133
 134 /*******************************************************************************
 135  *
 136  * FUNCTION:    acpi_ns_parse_table
 137  *
 138  * PARAMETERS:  table_desc      - An ACPI table descriptor for table to parse
 139  *              start_node      - Where to enter the table into the namespace
 140  *
 141  * RETURN:      Status
 142  *
 143  * DESCRIPTION: Parse AML within an ACPI table and return a tree of ops
 144  *
 145  ******************************************************************************/
 146
 147 acpi_status
 148 acpi_ns_parse_table(acpi_native_uint table_index,
 149                     struct acpi_namespace_node *start_node)
 150 {
 151         acpi_status status;
 152
 153         ACPI_FUNCTION_TRACE(ns_parse_table);
 154
 155         /*
 156          * AML Parse, pass 1
 157          *
 158          * In this pass, we load most of the namespace.  Control methods
 159          * are not parsed until later.  A parse tree is not created.  Instead,
 160          * each Parser Op subtree is deleted when it is finished.  This saves
 161          * a great deal of memory, and allows a small cache of parse objects
 162          * to service the entire parse.  The second pass of the parse then
 163          * performs another complete parse of the AML.
 164          */
 165         ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "**** Start pass 1\n"));
 166         status = acpi_ns_one_complete_parse(ACPI_IMODE_LOAD_PASS1, table_index);
 167         if (ACPI_FAILURE(status)) {
 168                 return_ACPI_STATUS(status);
 169         }
 170
 171         /*
 172          * AML Parse, pass 2
 173          *
 174          * In this pass, we resolve forward references and other things
 175          * that could not be completed during the first pass.
 176          * Another complete parse of the AML is performed, but the
 177          * overhead of this is compensated for by the fact that the
 178          * parse objects are all cached.
 179          */
 180         ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "**** Start pass 2\n"));
 181         status = acpi_ns_one_complete_parse(ACPI_IMODE_LOAD_PASS2, table_index);
 182         if (ACPI_FAILURE(status)) {
 183                 return_ACPI_STATUS(status);
 184         }
 185
 186         return_ACPI_STATUS(status);
 187 }