xref: /openbmc/linux/drivers/acpi/acpica/nsparse.c (revision 6d99a79c)
1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /******************************************************************************
3  *
4  * Module Name: nsparse - namespace interface to AML parser
5  *
6  * Copyright (C) 2000 - 2018, Intel Corp.
7  *
8  *****************************************************************************/
9 
10 #include <acpi/acpi.h>
11 #include "accommon.h"
12 #include "acnamesp.h"
13 #include "acparser.h"
14 #include "acdispat.h"
15 #include "actables.h"
16 #include "acinterp.h"
17 
18 #define _COMPONENT          ACPI_NAMESPACE
19 ACPI_MODULE_NAME("nsparse")
20 
21 /*******************************************************************************
22  *
23  * FUNCTION:    ns_execute_table
24  *
25  * PARAMETERS:  table_desc      - An ACPI table descriptor for table to parse
26  *              start_node      - Where to enter the table into the namespace
27  *
28  * RETURN:      Status
29  *
30  * DESCRIPTION: Load ACPI/AML table by executing the entire table as a single
31  *              large control method.
32  *
33  * NOTE: The point of this is to execute any module-level code in-place
34  * as the table is parsed. Some AML code depends on this behavior.
35  *
36  * It is a run-time option at this time, but will eventually become
37  * the default.
38  *
39  * Note: This causes the table to only have a single-pass parse.
40  * However, this is compatible with other ACPI implementations.
41  *
42  ******************************************************************************/
43 acpi_status
44 acpi_ns_execute_table(u32 table_index, struct acpi_namespace_node *start_node)
45 {
46 	acpi_status status;
47 	struct acpi_table_header *table;
48 	acpi_owner_id owner_id;
49 	struct acpi_evaluate_info *info = NULL;
50 	u32 aml_length;
51 	u8 *aml_start;
52 	union acpi_operand_object *method_obj = NULL;
53 
54 	ACPI_FUNCTION_TRACE(ns_execute_table);
55 
56 	status = acpi_get_table_by_index(table_index, &table);
57 	if (ACPI_FAILURE(status)) {
58 		return_ACPI_STATUS(status);
59 	}
60 
61 	/* Table must consist of at least a complete header */
62 
63 	if (table->length < sizeof(struct acpi_table_header)) {
64 		return_ACPI_STATUS(AE_BAD_HEADER);
65 	}
66 
67 	aml_start = (u8 *)table + sizeof(struct acpi_table_header);
68 	aml_length = table->length - sizeof(struct acpi_table_header);
69 
70 	status = acpi_tb_get_owner_id(table_index, &owner_id);
71 	if (ACPI_FAILURE(status)) {
72 		return_ACPI_STATUS(status);
73 	}
74 
75 	/* Create, initialize, and link a new temporary method object */
76 
77 	method_obj = acpi_ut_create_internal_object(ACPI_TYPE_METHOD);
78 	if (!method_obj) {
79 		return_ACPI_STATUS(AE_NO_MEMORY);
80 	}
81 
82 	/* Allocate the evaluation information block */
83 
84 	info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
85 	if (!info) {
86 		status = AE_NO_MEMORY;
87 		goto cleanup;
88 	}
89 
90 	ACPI_DEBUG_PRINT_RAW((ACPI_DB_PARSE,
91 			      "%s: Create table pseudo-method for [%4.4s] @%p, method %p\n",
92 			      ACPI_GET_FUNCTION_NAME, table->signature, table,
93 			      method_obj));
94 
95 	method_obj->method.aml_start = aml_start;
96 	method_obj->method.aml_length = aml_length;
97 	method_obj->method.owner_id = owner_id;
98 	method_obj->method.info_flags |= ACPI_METHOD_MODULE_LEVEL;
99 
100 	info->pass_number = ACPI_IMODE_EXECUTE;
101 	info->node = start_node;
102 	info->obj_desc = method_obj;
103 	info->node_flags = info->node->flags;
104 	info->full_pathname = acpi_ns_get_normalized_pathname(info->node, TRUE);
105 	if (!info->full_pathname) {
106 		status = AE_NO_MEMORY;
107 		goto cleanup;
108 	}
109 
110 	status = acpi_ps_execute_table(info);
111 
112 cleanup:
113 	if (info) {
114 		ACPI_FREE(info->full_pathname);
115 		info->full_pathname = NULL;
116 	}
117 	ACPI_FREE(info);
118 	acpi_ut_remove_reference(method_obj);
119 	return_ACPI_STATUS(status);
120 }
121 
122 /*******************************************************************************
123  *
124  * FUNCTION:    ns_one_complete_parse
125  *
126  * PARAMETERS:  pass_number             - 1 or 2
127  *              table_desc              - The table to be parsed.
128  *
129  * RETURN:      Status
130  *
131  * DESCRIPTION: Perform one complete parse of an ACPI/AML table.
132  *
133  ******************************************************************************/
134 
135 acpi_status
136 acpi_ns_one_complete_parse(u32 pass_number,
137 			   u32 table_index,
138 			   struct acpi_namespace_node *start_node)
139 {
140 	union acpi_parse_object *parse_root;
141 	acpi_status status;
142 	u32 aml_length;
143 	u8 *aml_start;
144 	struct acpi_walk_state *walk_state;
145 	struct acpi_table_header *table;
146 	acpi_owner_id owner_id;
147 
148 	ACPI_FUNCTION_TRACE(ns_one_complete_parse);
149 
150 	status = acpi_get_table_by_index(table_index, &table);
151 	if (ACPI_FAILURE(status)) {
152 		return_ACPI_STATUS(status);
153 	}
154 
155 	/* Table must consist of at least a complete header */
156 
157 	if (table->length < sizeof(struct acpi_table_header)) {
158 		return_ACPI_STATUS(AE_BAD_HEADER);
159 	}
160 
161 	aml_start = (u8 *)table + sizeof(struct acpi_table_header);
162 	aml_length = table->length - sizeof(struct acpi_table_header);
163 
164 	status = acpi_tb_get_owner_id(table_index, &owner_id);
165 	if (ACPI_FAILURE(status)) {
166 		return_ACPI_STATUS(status);
167 	}
168 
169 	/* Create and init a Root Node */
170 
171 	parse_root = acpi_ps_create_scope_op(aml_start);
172 	if (!parse_root) {
173 		return_ACPI_STATUS(AE_NO_MEMORY);
174 	}
175 
176 	/* Create and initialize a new walk state */
177 
178 	walk_state = acpi_ds_create_walk_state(owner_id, NULL, NULL, NULL);
179 	if (!walk_state) {
180 		acpi_ps_free_op(parse_root);
181 		return_ACPI_STATUS(AE_NO_MEMORY);
182 	}
183 
184 	status = acpi_ds_init_aml_walk(walk_state, parse_root, NULL,
185 				       aml_start, aml_length, NULL,
186 				       (u8)pass_number);
187 	if (ACPI_FAILURE(status)) {
188 		acpi_ds_delete_walk_state(walk_state);
189 		goto cleanup;
190 	}
191 
192 	/* Found OSDT table, enable the namespace override feature */
193 
194 	if (ACPI_COMPARE_NAME(table->signature, ACPI_SIG_OSDT) &&
195 	    pass_number == ACPI_IMODE_LOAD_PASS1) {
196 		walk_state->namespace_override = TRUE;
197 	}
198 
199 	/* start_node is the default location to load the table */
200 
201 	if (start_node && start_node != acpi_gbl_root_node) {
202 		status =
203 		    acpi_ds_scope_stack_push(start_node, ACPI_TYPE_METHOD,
204 					     walk_state);
205 		if (ACPI_FAILURE(status)) {
206 			acpi_ds_delete_walk_state(walk_state);
207 			goto cleanup;
208 		}
209 	}
210 
211 	/* Parse the AML */
212 
213 	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
214 			  "*PARSE* pass %u parse\n", pass_number));
215 	acpi_ex_enter_interpreter();
216 	status = acpi_ps_parse_aml(walk_state);
217 	acpi_ex_exit_interpreter();
218 
219 cleanup:
220 	acpi_ps_delete_parse_tree(parse_root);
221 	return_ACPI_STATUS(status);
222 }
223 
224 /*******************************************************************************
225  *
226  * FUNCTION:    acpi_ns_parse_table
227  *
228  * PARAMETERS:  table_desc      - An ACPI table descriptor for table to parse
229  *              start_node      - Where to enter the table into the namespace
230  *
231  * RETURN:      Status
232  *
233  * DESCRIPTION: Parse AML within an ACPI table and return a tree of ops
234  *
235  ******************************************************************************/
236 
237 acpi_status
238 acpi_ns_parse_table(u32 table_index, struct acpi_namespace_node *start_node)
239 {
240 	acpi_status status;
241 
242 	ACPI_FUNCTION_TRACE(ns_parse_table);
243 
244 	if (acpi_gbl_execute_tables_as_methods) {
245 		/*
246 		 * This case executes the AML table as one large control method.
247 		 * The point of this is to execute any module-level code in-place
248 		 * as the table is parsed. Some AML code depends on this behavior.
249 		 *
250 		 * It is a run-time option at this time, but will eventually become
251 		 * the default.
252 		 *
253 		 * Note: This causes the table to only have a single-pass parse.
254 		 * However, this is compatible with other ACPI implementations.
255 		 */
256 		ACPI_DEBUG_PRINT_RAW((ACPI_DB_PARSE,
257 				      "%s: **** Start table execution pass\n",
258 				      ACPI_GET_FUNCTION_NAME));
259 
260 		status = acpi_ns_execute_table(table_index, start_node);
261 		if (ACPI_FAILURE(status)) {
262 			return_ACPI_STATUS(status);
263 		}
264 	} else {
265 		/*
266 		 * AML Parse, pass 1
267 		 *
268 		 * In this pass, we load most of the namespace. Control methods
269 		 * are not parsed until later. A parse tree is not created.
270 		 * Instead, each Parser Op subtree is deleted when it is finished.
271 		 * This saves a great deal of memory, and allows a small cache of
272 		 * parse objects to service the entire parse. The second pass of
273 		 * the parse then performs another complete parse of the AML.
274 		 */
275 		ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "**** Start pass 1\n"));
276 
277 		status = acpi_ns_one_complete_parse(ACPI_IMODE_LOAD_PASS1,
278 						    table_index, start_node);
279 		if (ACPI_FAILURE(status)) {
280 			return_ACPI_STATUS(status);
281 		}
282 
283 		/*
284 		 * AML Parse, pass 2
285 		 *
286 		 * In this pass, we resolve forward references and other things
287 		 * that could not be completed during the first pass.
288 		 * Another complete parse of the AML is performed, but the
289 		 * overhead of this is compensated for by the fact that the
290 		 * parse objects are all cached.
291 		 */
292 		ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "**** Start pass 2\n"));
293 		status = acpi_ns_one_complete_parse(ACPI_IMODE_LOAD_PASS2,
294 						    table_index, start_node);
295 		if (ACPI_FAILURE(status)) {
296 			return_ACPI_STATUS(status);
297 		}
298 	}
299 
300 	return_ACPI_STATUS(status);
301 }
302