1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /******************************************************************************
3  *
4  * Module Name: exconfig - Namespace reconfiguration (Load/Unload opcodes)
5  *
6  * Copyright (C) 2000 - 2021, Intel Corp.
7  *
8  *****************************************************************************/
9 
10 #include <acpi/acpi.h>
11 #include "accommon.h"
12 #include "acinterp.h"
13 #include "acnamesp.h"
14 #include "actables.h"
15 #include "acdispat.h"
16 #include "acevents.h"
17 #include "amlcode.h"
18 
19 #define _COMPONENT          ACPI_EXECUTER
20 ACPI_MODULE_NAME("exconfig")
21 
22 /* Local prototypes */
23 static acpi_status
24 acpi_ex_add_table(u32 table_index, union acpi_operand_object **ddb_handle);
25 
26 static acpi_status
27 acpi_ex_region_read(union acpi_operand_object *obj_desc,
28 		    u32 length, u8 *buffer);
29 
30 /*******************************************************************************
31  *
32  * FUNCTION:    acpi_ex_add_table
33  *
34  * PARAMETERS:  table               - Pointer to raw table
35  *              parent_node         - Where to load the table (scope)
36  *              ddb_handle          - Where to return the table handle.
37  *
38  * RETURN:      Status
39  *
40  * DESCRIPTION: Common function to Install and Load an ACPI table with a
41  *              returned table handle.
42  *
43  ******************************************************************************/
44 
45 static acpi_status
acpi_ex_add_table(u32 table_index,union acpi_operand_object ** ddb_handle)46 acpi_ex_add_table(u32 table_index, union acpi_operand_object **ddb_handle)
47 {
48 	union acpi_operand_object *obj_desc;
49 
50 	ACPI_FUNCTION_TRACE(ex_add_table);
51 
52 	/* Create an object to be the table handle */
53 
54 	obj_desc = acpi_ut_create_internal_object(ACPI_TYPE_LOCAL_REFERENCE);
55 	if (!obj_desc) {
56 		return_ACPI_STATUS(AE_NO_MEMORY);
57 	}
58 
59 	/* Init the table handle */
60 
61 	obj_desc->common.flags |= AOPOBJ_DATA_VALID;
62 	obj_desc->reference.class = ACPI_REFCLASS_TABLE;
63 	obj_desc->reference.value = table_index;
64 	*ddb_handle = obj_desc;
65 	return_ACPI_STATUS(AE_OK);
66 }
67 
68 /*******************************************************************************
69  *
70  * FUNCTION:    acpi_ex_load_table_op
71  *
72  * PARAMETERS:  walk_state          - Current state with operands
73  *              return_desc         - Where to store the return object
74  *
75  * RETURN:      Status
76  *
77  * DESCRIPTION: Load an ACPI table from the RSDT/XSDT
78  *
79  ******************************************************************************/
80 
81 acpi_status
acpi_ex_load_table_op(struct acpi_walk_state * walk_state,union acpi_operand_object ** return_desc)82 acpi_ex_load_table_op(struct acpi_walk_state *walk_state,
83 		      union acpi_operand_object **return_desc)
84 {
85 	acpi_status status;
86 	union acpi_operand_object **operand = &walk_state->operands[0];
87 	struct acpi_namespace_node *parent_node;
88 	struct acpi_namespace_node *start_node;
89 	struct acpi_namespace_node *parameter_node = NULL;
90 	union acpi_operand_object *ddb_handle;
91 	u32 table_index;
92 
93 	ACPI_FUNCTION_TRACE(ex_load_table_op);
94 
95 	/* Find the ACPI table in the RSDT/XSDT */
96 
97 	acpi_ex_exit_interpreter();
98 	status = acpi_tb_find_table(operand[0]->string.pointer,
99 				    operand[1]->string.pointer,
100 				    operand[2]->string.pointer, &table_index);
101 	acpi_ex_enter_interpreter();
102 	if (ACPI_FAILURE(status)) {
103 		if (status != AE_NOT_FOUND) {
104 			return_ACPI_STATUS(status);
105 		}
106 
107 		/* Table not found, return an Integer=0 and AE_OK */
108 
109 		ddb_handle = acpi_ut_create_integer_object((u64) 0);
110 		if (!ddb_handle) {
111 			return_ACPI_STATUS(AE_NO_MEMORY);
112 		}
113 
114 		*return_desc = ddb_handle;
115 		return_ACPI_STATUS(AE_OK);
116 	}
117 
118 	/* Default nodes */
119 
120 	start_node = walk_state->scope_info->scope.node;
121 	parent_node = acpi_gbl_root_node;
122 
123 	/* root_path (optional parameter) */
124 
125 	if (operand[3]->string.length > 0) {
126 		/*
127 		 * Find the node referenced by the root_path_string. This is the
128 		 * location within the namespace where the table will be loaded.
129 		 */
130 		status = acpi_ns_get_node_unlocked(start_node,
131 						   operand[3]->string.pointer,
132 						   ACPI_NS_SEARCH_PARENT,
133 						   &parent_node);
134 		if (ACPI_FAILURE(status)) {
135 			return_ACPI_STATUS(status);
136 		}
137 	}
138 
139 	/* parameter_path (optional parameter) */
140 
141 	if (operand[4]->string.length > 0) {
142 		if ((operand[4]->string.pointer[0] != AML_ROOT_PREFIX) &&
143 		    (operand[4]->string.pointer[0] != AML_PARENT_PREFIX)) {
144 			/*
145 			 * Path is not absolute, so it will be relative to the node
146 			 * referenced by the root_path_string (or the NS root if omitted)
147 			 */
148 			start_node = parent_node;
149 		}
150 
151 		/* Find the node referenced by the parameter_path_string */
152 
153 		status = acpi_ns_get_node_unlocked(start_node,
154 						   operand[4]->string.pointer,
155 						   ACPI_NS_SEARCH_PARENT,
156 						   &parameter_node);
157 		if (ACPI_FAILURE(status)) {
158 			return_ACPI_STATUS(status);
159 		}
160 	}
161 
162 	/* Load the table into the namespace */
163 
164 	ACPI_INFO(("Dynamic OEM Table Load:"));
165 	acpi_ex_exit_interpreter();
166 	status = acpi_tb_load_table(table_index, parent_node);
167 	acpi_ex_enter_interpreter();
168 	if (ACPI_FAILURE(status)) {
169 		return_ACPI_STATUS(status);
170 	}
171 
172 	status = acpi_ex_add_table(table_index, &ddb_handle);
173 	if (ACPI_FAILURE(status)) {
174 		return_ACPI_STATUS(status);
175 	}
176 
177 	/* Complete the initialization/resolution of new objects */
178 
179 	acpi_ex_exit_interpreter();
180 	acpi_ns_initialize_objects();
181 	acpi_ex_enter_interpreter();
182 
183 	/* Parameter Data (optional) */
184 
185 	if (parameter_node) {
186 
187 		/* Store the parameter data into the optional parameter object */
188 
189 		status = acpi_ex_store(operand[5],
190 				       ACPI_CAST_PTR(union acpi_operand_object,
191 						     parameter_node),
192 				       walk_state);
193 		if (ACPI_FAILURE(status)) {
194 			(void)acpi_ex_unload_table(ddb_handle);
195 
196 			acpi_ut_remove_reference(ddb_handle);
197 			return_ACPI_STATUS(status);
198 		}
199 	}
200 
201 	*return_desc = ddb_handle;
202 	return_ACPI_STATUS(status);
203 }
204 
205 /*******************************************************************************
206  *
207  * FUNCTION:    acpi_ex_region_read
208  *
209  * PARAMETERS:  obj_desc        - Region descriptor
210  *              length          - Number of bytes to read
211  *              buffer          - Pointer to where to put the data
212  *
213  * RETURN:      Status
214  *
215  * DESCRIPTION: Read data from an operation region. The read starts from the
216  *              beginning of the region.
217  *
218  ******************************************************************************/
219 
220 static acpi_status
acpi_ex_region_read(union acpi_operand_object * obj_desc,u32 length,u8 * buffer)221 acpi_ex_region_read(union acpi_operand_object *obj_desc, u32 length, u8 *buffer)
222 {
223 	acpi_status status;
224 	u64 value;
225 	u32 region_offset = 0;
226 	u32 i;
227 
228 	/* Bytewise reads */
229 
230 	for (i = 0; i < length; i++) {
231 		status =
232 		    acpi_ev_address_space_dispatch(obj_desc, NULL, ACPI_READ,
233 						   region_offset, 8, &value);
234 		if (ACPI_FAILURE(status)) {
235 			return (status);
236 		}
237 
238 		*buffer = (u8)value;
239 		buffer++;
240 		region_offset++;
241 	}
242 
243 	return (AE_OK);
244 }
245 
246 /*******************************************************************************
247  *
248  * FUNCTION:    acpi_ex_load_op
249  *
250  * PARAMETERS:  obj_desc        - Region or Buffer/Field where the table will be
251  *                                obtained
252  *              target          - Where a handle to the table will be stored
253  *              walk_state      - Current state
254  *
255  * RETURN:      Status
256  *
257  * DESCRIPTION: Load an ACPI table from a field or operation region
258  *
259  * NOTE: Region Fields (Field, bank_field, index_fields) are resolved to buffer
260  *       objects before this code is reached.
261  *
262  *       If source is an operation region, it must refer to system_memory, as
263  *       per the ACPI specification.
264  *
265  ******************************************************************************/
266 
267 acpi_status
acpi_ex_load_op(union acpi_operand_object * obj_desc,union acpi_operand_object * target,struct acpi_walk_state * walk_state)268 acpi_ex_load_op(union acpi_operand_object *obj_desc,
269 		union acpi_operand_object *target,
270 		struct acpi_walk_state *walk_state)
271 {
272 	union acpi_operand_object *ddb_handle;
273 	struct acpi_table_header *table_header;
274 	struct acpi_table_header *table;
275 	u32 table_index;
276 	acpi_status status;
277 	u32 length;
278 
279 	ACPI_FUNCTION_TRACE(ex_load_op);
280 
281 	/* Source Object can be either an op_region or a Buffer/Field */
282 
283 	switch (obj_desc->common.type) {
284 	case ACPI_TYPE_REGION:
285 
286 		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
287 				  "Load table from Region %p\n", obj_desc));
288 
289 		/* Region must be system_memory (from ACPI spec) */
290 
291 		if (obj_desc->region.space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) {
292 			return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
293 		}
294 
295 		/*
296 		 * If the Region Address and Length have not been previously
297 		 * evaluated, evaluate them now and save the results.
298 		 */
299 		if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
300 			status = acpi_ds_get_region_arguments(obj_desc);
301 			if (ACPI_FAILURE(status)) {
302 				return_ACPI_STATUS(status);
303 			}
304 		}
305 
306 		/* Get the table header first so we can get the table length */
307 
308 		table_header = ACPI_ALLOCATE(sizeof(struct acpi_table_header));
309 		if (!table_header) {
310 			return_ACPI_STATUS(AE_NO_MEMORY);
311 		}
312 
313 		status =
314 		    acpi_ex_region_read(obj_desc,
315 					sizeof(struct acpi_table_header),
316 					ACPI_CAST_PTR(u8, table_header));
317 		length = table_header->length;
318 		ACPI_FREE(table_header);
319 
320 		if (ACPI_FAILURE(status)) {
321 			return_ACPI_STATUS(status);
322 		}
323 
324 		/* Must have at least an ACPI table header */
325 
326 		if (length < sizeof(struct acpi_table_header)) {
327 			return_ACPI_STATUS(AE_INVALID_TABLE_LENGTH);
328 		}
329 
330 		/*
331 		 * The original implementation simply mapped the table, with no copy.
332 		 * However, the memory region is not guaranteed to remain stable and
333 		 * we must copy the table to a local buffer. For example, the memory
334 		 * region is corrupted after suspend on some machines. Dynamically
335 		 * loaded tables are usually small, so this overhead is minimal.
336 		 *
337 		 * The latest implementation (5/2009) does not use a mapping at all.
338 		 * We use the low-level operation region interface to read the table
339 		 * instead of the obvious optimization of using a direct mapping.
340 		 * This maintains a consistent use of operation regions across the
341 		 * entire subsystem. This is important if additional processing must
342 		 * be performed in the (possibly user-installed) operation region
343 		 * handler. For example, acpi_exec and ASLTS depend on this.
344 		 */
345 
346 		/* Allocate a buffer for the table */
347 
348 		table = ACPI_ALLOCATE(length);
349 		if (!table) {
350 			return_ACPI_STATUS(AE_NO_MEMORY);
351 		}
352 
353 		/* Read the entire table */
354 
355 		status = acpi_ex_region_read(obj_desc, length,
356 					     ACPI_CAST_PTR(u8, table));
357 		if (ACPI_FAILURE(status)) {
358 			ACPI_FREE(table);
359 			return_ACPI_STATUS(status);
360 		}
361 		break;
362 
363 	case ACPI_TYPE_BUFFER:	/* Buffer or resolved region_field */
364 
365 		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
366 				  "Load table from Buffer or Field %p\n",
367 				  obj_desc));
368 
369 		/* Must have at least an ACPI table header */
370 
371 		if (obj_desc->buffer.length < sizeof(struct acpi_table_header)) {
372 			return_ACPI_STATUS(AE_INVALID_TABLE_LENGTH);
373 		}
374 
375 		/* Get the actual table length from the table header */
376 
377 		table_header =
378 		    ACPI_CAST_PTR(struct acpi_table_header,
379 				  obj_desc->buffer.pointer);
380 		length = table_header->length;
381 
382 		/* Table cannot extend beyond the buffer */
383 
384 		if (length > obj_desc->buffer.length) {
385 			return_ACPI_STATUS(AE_AML_BUFFER_LIMIT);
386 		}
387 		if (length < sizeof(struct acpi_table_header)) {
388 			return_ACPI_STATUS(AE_INVALID_TABLE_LENGTH);
389 		}
390 
391 		/*
392 		 * Copy the table from the buffer because the buffer could be
393 		 * modified or even deleted in the future
394 		 */
395 		table = ACPI_ALLOCATE(length);
396 		if (!table) {
397 			return_ACPI_STATUS(AE_NO_MEMORY);
398 		}
399 
400 		memcpy(table, table_header, length);
401 		break;
402 
403 	default:
404 
405 		return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
406 	}
407 
408 	/* Install the new table into the local data structures */
409 
410 	ACPI_INFO(("Dynamic OEM Table Load:"));
411 	acpi_ex_exit_interpreter();
412 	status = acpi_tb_install_and_load_table(ACPI_PTR_TO_PHYSADDR(table),
413 						ACPI_TABLE_ORIGIN_INTERNAL_VIRTUAL,
414 						TRUE, &table_index);
415 	acpi_ex_enter_interpreter();
416 	if (ACPI_FAILURE(status)) {
417 
418 		/* Delete allocated table buffer */
419 
420 		ACPI_FREE(table);
421 		return_ACPI_STATUS(status);
422 	}
423 
424 	/*
425 	 * Add the table to the namespace.
426 	 *
427 	 * Note: Load the table objects relative to the root of the namespace.
428 	 * This appears to go against the ACPI specification, but we do it for
429 	 * compatibility with other ACPI implementations.
430 	 */
431 	status = acpi_ex_add_table(table_index, &ddb_handle);
432 	if (ACPI_FAILURE(status)) {
433 
434 		/* On error, table_ptr was deallocated above */
435 
436 		return_ACPI_STATUS(status);
437 	}
438 
439 	/* Complete the initialization/resolution of new objects */
440 
441 	acpi_ex_exit_interpreter();
442 	acpi_ns_initialize_objects();
443 	acpi_ex_enter_interpreter();
444 
445 	/* Store the ddb_handle into the Target operand */
446 
447 	status = acpi_ex_store(ddb_handle, target, walk_state);
448 	if (ACPI_FAILURE(status)) {
449 		(void)acpi_ex_unload_table(ddb_handle);
450 
451 		/* table_ptr was deallocated above */
452 
453 		acpi_ut_remove_reference(ddb_handle);
454 		return_ACPI_STATUS(status);
455 	}
456 
457 	/* Remove the reference by added by acpi_ex_store above */
458 
459 	acpi_ut_remove_reference(ddb_handle);
460 	return_ACPI_STATUS(status);
461 }
462 
463 /*******************************************************************************
464  *
465  * FUNCTION:    acpi_ex_unload_table
466  *
467  * PARAMETERS:  ddb_handle          - Handle to a previously loaded table
468  *
469  * RETURN:      Status
470  *
471  * DESCRIPTION: Unload an ACPI table
472  *
473  ******************************************************************************/
474 
acpi_ex_unload_table(union acpi_operand_object * ddb_handle)475 acpi_status acpi_ex_unload_table(union acpi_operand_object *ddb_handle)
476 {
477 	acpi_status status = AE_OK;
478 	union acpi_operand_object *table_desc = ddb_handle;
479 	u32 table_index;
480 
481 	ACPI_FUNCTION_TRACE(ex_unload_table);
482 
483 	/*
484 	 * Temporarily emit a warning so that the ASL for the machine can be
485 	 * hopefully obtained. This is to say that the Unload() operator is
486 	 * extremely rare if not completely unused.
487 	 */
488 	ACPI_WARNING((AE_INFO, "Received request to unload an ACPI table"));
489 
490 	/*
491 	 * May 2018: Unload is no longer supported for the following reasons:
492 	 * 1) A correct implementation on some hosts may not be possible.
493 	 * 2) Other ACPI implementations do not correctly/fully support it.
494 	 * 3) It requires host device driver support which does not exist.
495 	 *    (To properly support namespace unload out from underneath.)
496 	 * 4) This AML operator has never been seen in the field.
497 	 */
498 	ACPI_EXCEPTION((AE_INFO, AE_NOT_IMPLEMENTED,
499 			"AML Unload operator is not supported"));
500 
501 	/*
502 	 * Validate the handle
503 	 * Although the handle is partially validated in acpi_ex_reconfiguration()
504 	 * when it calls acpi_ex_resolve_operands(), the handle is more completely
505 	 * validated here.
506 	 *
507 	 * Handle must be a valid operand object of type reference. Also, the
508 	 * ddb_handle must still be marked valid (table has not been previously
509 	 * unloaded)
510 	 */
511 	if ((!ddb_handle) ||
512 	    (ACPI_GET_DESCRIPTOR_TYPE(ddb_handle) != ACPI_DESC_TYPE_OPERAND) ||
513 	    (ddb_handle->common.type != ACPI_TYPE_LOCAL_REFERENCE) ||
514 	    (!(ddb_handle->common.flags & AOPOBJ_DATA_VALID))) {
515 		return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
516 	}
517 
518 	/* Get the table index from the ddb_handle */
519 
520 	table_index = table_desc->reference.value;
521 
522 	/*
523 	 * Release the interpreter lock so that the table lock won't have
524 	 * strict order requirement against it.
525 	 */
526 	acpi_ex_exit_interpreter();
527 	status = acpi_tb_unload_table(table_index);
528 	acpi_ex_enter_interpreter();
529 
530 	/*
531 	 * Invalidate the handle. We do this because the handle may be stored
532 	 * in a named object and may not be actually deleted until much later.
533 	 */
534 	if (ACPI_SUCCESS(status)) {
535 		ddb_handle->common.flags &= ~AOPOBJ_DATA_VALID;
536 	}
537 	return_ACPI_STATUS(status);
538 }
539