drivers/acpi/namespace/nsparse.c

   1 /******************************************************************************
   2  *
   3  * Module Name: nsparse - namespace interface to AML parser
   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/accommon.h>
  46 #include <acpi/acnamesp.h>
  47 #include <acpi/acparser.h>
  48 #include <acpi/acdispat.h>
  49 #include <acpi/actables.h>
  50
  51 #define _COMPONENT          ACPI_NAMESPACE
  52 ACPI_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  ******************************************************************************/
  66 acpi_status
  67 acpi_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 %d parse\n",
 140                           (unsigned)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
 161 acpi_status
 162 acpi_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 =
 180             acpi_ns_one_complete_parse(ACPI_IMODE_LOAD_PASS1, table_index,
 181                                        start_node);
 182         if (ACPI_FAILURE(status)) {
 183                 return_ACPI_STATUS(status);
 184         }
 185
 186         /*
 187          * AML Parse, pass 2
 188          *
 189          * In this pass, we resolve forward references and other things
 190          * that could not be completed during the first pass.
 191          * Another complete parse of the AML is performed, but the
 192          * overhead of this is compensated for by the fact that the
 193          * parse objects are all cached.
 194          */
 195         ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "**** Start pass 2\n"));
 196         status =
 197             acpi_ns_one_complete_parse(ACPI_IMODE_LOAD_PASS2, table_index,
 198                                        start_node);
 199         if (ACPI_FAILURE(status)) {
 200                 return_ACPI_STATUS(status);
 201         }
 202
 203         return_ACPI_STATUS(status);
 204 }