xref: /openbmc/linux/drivers/acpi/acpica/nsparse.c (revision bc5aa3a0)
1 /******************************************************************************
2  *
3  * Module Name: nsparse - namespace interface to AML parser
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2016, 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_get_table_by_index(table_index, &table);
82 	if (ACPI_FAILURE(status)) {
83 		return_ACPI_STATUS(status);
84 	}
85 
86 	/* Table must consist of at least a complete header */
87 
88 	if (table->length < sizeof(struct acpi_table_header)) {
89 		return_ACPI_STATUS(AE_BAD_HEADER);
90 	}
91 
92 	aml_start = (u8 *)table + sizeof(struct acpi_table_header);
93 	aml_length = table->length - sizeof(struct acpi_table_header);
94 
95 	status = acpi_tb_get_owner_id(table_index, &owner_id);
96 	if (ACPI_FAILURE(status)) {
97 		return_ACPI_STATUS(status);
98 	}
99 
100 	/* Create and init a Root Node */
101 
102 	parse_root = acpi_ps_create_scope_op(aml_start);
103 	if (!parse_root) {
104 		return_ACPI_STATUS(AE_NO_MEMORY);
105 	}
106 
107 	/* Create and initialize a new walk state */
108 
109 	walk_state = acpi_ds_create_walk_state(owner_id, NULL, NULL, NULL);
110 	if (!walk_state) {
111 		acpi_ps_free_op(parse_root);
112 		return_ACPI_STATUS(AE_NO_MEMORY);
113 	}
114 
115 	status = acpi_ds_init_aml_walk(walk_state, parse_root, NULL,
116 				       aml_start, aml_length, NULL,
117 				       (u8)pass_number);
118 	if (ACPI_FAILURE(status)) {
119 		acpi_ds_delete_walk_state(walk_state);
120 		goto cleanup;
121 	}
122 
123 	/* Found OSDT table, enable the namespace override feature */
124 
125 	if (ACPI_COMPARE_NAME(table->signature, ACPI_SIG_OSDT) &&
126 	    pass_number == ACPI_IMODE_LOAD_PASS1) {
127 		walk_state->namespace_override = TRUE;
128 	}
129 
130 	/* start_node is the default location to load the table */
131 
132 	if (start_node && start_node != acpi_gbl_root_node) {
133 		status =
134 		    acpi_ds_scope_stack_push(start_node, ACPI_TYPE_METHOD,
135 					     walk_state);
136 		if (ACPI_FAILURE(status)) {
137 			acpi_ds_delete_walk_state(walk_state);
138 			goto cleanup;
139 		}
140 	}
141 
142 	/* Parse the AML */
143 
144 	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
145 			  "*PARSE* pass %u parse\n", pass_number));
146 	status = acpi_ps_parse_aml(walk_state);
147 
148 cleanup:
149 	acpi_ps_delete_parse_tree(parse_root);
150 	return_ACPI_STATUS(status);
151 }
152 
153 /*******************************************************************************
154  *
155  * FUNCTION:    acpi_ns_parse_table
156  *
157  * PARAMETERS:  table_desc      - An ACPI table descriptor for table to parse
158  *              start_node      - Where to enter the table into the namespace
159  *
160  * RETURN:      Status
161  *
162  * DESCRIPTION: Parse AML within an ACPI table and return a tree of ops
163  *
164  ******************************************************************************/
165 
166 acpi_status
167 acpi_ns_parse_table(u32 table_index, struct acpi_namespace_node *start_node)
168 {
169 	acpi_status status;
170 
171 	ACPI_FUNCTION_TRACE(ns_parse_table);
172 
173 	/*
174 	 * AML Parse, pass 1
175 	 *
176 	 * In this pass, we load most of the namespace. Control methods
177 	 * are not parsed until later. A parse tree is not created. Instead,
178 	 * each Parser Op subtree is deleted when it is finished. This saves
179 	 * a great deal of memory, and allows a small cache of parse objects
180 	 * to service the entire parse. The second pass of the parse then
181 	 * performs another complete parse of the AML.
182 	 */
183 	ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "**** Start pass 1\n"));
184 
185 	status = acpi_ns_one_complete_parse(ACPI_IMODE_LOAD_PASS1,
186 					    table_index, start_node);
187 	if (ACPI_FAILURE(status)) {
188 		return_ACPI_STATUS(status);
189 	}
190 
191 	/*
192 	 * AML Parse, pass 2
193 	 *
194 	 * In this pass, we resolve forward references and other things
195 	 * that could not be completed during the first pass.
196 	 * Another complete parse of the AML is performed, but the
197 	 * overhead of this is compensated for by the fact that the
198 	 * parse objects are all cached.
199 	 */
200 	ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "**** Start pass 2\n"));
201 	status = acpi_ns_one_complete_parse(ACPI_IMODE_LOAD_PASS2,
202 					    table_index, start_node);
203 	if (ACPI_FAILURE(status)) {
204 		return_ACPI_STATUS(status);
205 	}
206 
207 	return_ACPI_STATUS(status);
208 }
209