xref: /linux/drivers/acpi/acpica/nsparse.c (revision 005438a8eef063495ac059d128eea71b58de50e5)
1 /******************************************************************************
2  *
3  * Module Name: nsparse - namespace interface to AML parser
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2015, 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
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 	/* Found OSDT table, enable the namespace override feature */
121 
122 	if (ACPI_COMPARE_NAME(table->signature, ACPI_SIG_OSDT) &&
123 	    pass_number == ACPI_IMODE_LOAD_PASS1) {
124 		walk_state->namespace_override = TRUE;
125 	}
126 
127 	if (ACPI_FAILURE(status)) {
128 		acpi_ds_delete_walk_state(walk_state);
129 		goto cleanup;
130 	}
131 
132 	/* start_node is the default location to load the table */
133 
134 	if (start_node && start_node != acpi_gbl_root_node) {
135 		status =
136 		    acpi_ds_scope_stack_push(start_node, ACPI_TYPE_METHOD,
137 					     walk_state);
138 		if (ACPI_FAILURE(status)) {
139 			acpi_ds_delete_walk_state(walk_state);
140 			goto cleanup;
141 		}
142 	}
143 
144 	/* Parse the AML */
145 
146 	ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "*PARSE* pass %u parse\n",
147 			  pass_number));
148 	status = acpi_ps_parse_aml(walk_state);
149 
150 cleanup:
151 	acpi_ps_delete_parse_tree(parse_root);
152 	return_ACPI_STATUS(status);
153 }
154 
155 /*******************************************************************************
156  *
157  * FUNCTION:    acpi_ns_parse_table
158  *
159  * PARAMETERS:  table_desc      - An ACPI table descriptor for table to parse
160  *              start_node      - Where to enter the table into the namespace
161  *
162  * RETURN:      Status
163  *
164  * DESCRIPTION: Parse AML within an ACPI table and return a tree of ops
165  *
166  ******************************************************************************/
167 
168 acpi_status
169 acpi_ns_parse_table(u32 table_index, struct acpi_namespace_node *start_node)
170 {
171 	acpi_status status;
172 
173 	ACPI_FUNCTION_TRACE(ns_parse_table);
174 
175 	/*
176 	 * AML Parse, pass 1
177 	 *
178 	 * In this pass, we load most of the namespace. Control methods
179 	 * are not parsed until later. A parse tree is not created. Instead,
180 	 * each Parser Op subtree is deleted when it is finished. This saves
181 	 * a great deal of memory, and allows a small cache of parse objects
182 	 * to service the entire parse. The second pass of the parse then
183 	 * performs another complete parse of the AML.
184 	 */
185 	ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "**** Start pass 1\n"));
186 	status = acpi_ns_one_complete_parse(ACPI_IMODE_LOAD_PASS1,
187 					    table_index, start_node);
188 	if (ACPI_FAILURE(status)) {
189 		return_ACPI_STATUS(status);
190 	}
191 
192 	/*
193 	 * AML Parse, pass 2
194 	 *
195 	 * In this pass, we resolve forward references and other things
196 	 * that could not be completed during the first pass.
197 	 * Another complete parse of the AML is performed, but the
198 	 * overhead of this is compensated for by the fact that the
199 	 * parse objects are all cached.
200 	 */
201 	ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "**** Start pass 2\n"));
202 	status = acpi_ns_one_complete_parse(ACPI_IMODE_LOAD_PASS2,
203 					    table_index, start_node);
204 	if (ACPI_FAILURE(status)) {
205 		return_ACPI_STATUS(status);
206 	}
207 
208 	return_ACPI_STATUS(status);
209 }
210