1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2/*******************************************************************************
3 *
4 * Module Name: utresrc - Resource management utilities
5 *
6 ******************************************************************************/
7
8#include <acpi/acpi.h>
9#include "accommon.h"
10#include "acresrc.h"
11
12#define _COMPONENT          ACPI_UTILITIES
13ACPI_MODULE_NAME("utresrc")
14
15/*
16 * Base sizes of the raw AML resource descriptors, indexed by resource type.
17 * Zero indicates a reserved (and therefore invalid) resource type.
18 */
19const u8 acpi_gbl_resource_aml_sizes[] = {
20	/* Small descriptors */
21
22	0,
23	0,
24	0,
25	0,
26	ACPI_AML_SIZE_SMALL(struct aml_resource_irq),
27	ACPI_AML_SIZE_SMALL(struct aml_resource_dma),
28	ACPI_AML_SIZE_SMALL(struct aml_resource_start_dependent),
29	ACPI_AML_SIZE_SMALL(struct aml_resource_end_dependent),
30	ACPI_AML_SIZE_SMALL(struct aml_resource_io),
31	ACPI_AML_SIZE_SMALL(struct aml_resource_fixed_io),
32	ACPI_AML_SIZE_SMALL(struct aml_resource_fixed_dma),
33	0,
34	0,
35	0,
36	ACPI_AML_SIZE_SMALL(struct aml_resource_vendor_small),
37	ACPI_AML_SIZE_SMALL(struct aml_resource_end_tag),
38
39	/* Large descriptors */
40
41	0,
42	ACPI_AML_SIZE_LARGE(struct aml_resource_memory24),
43	ACPI_AML_SIZE_LARGE(struct aml_resource_generic_register),
44	0,
45	ACPI_AML_SIZE_LARGE(struct aml_resource_vendor_large),
46	ACPI_AML_SIZE_LARGE(struct aml_resource_memory32),
47	ACPI_AML_SIZE_LARGE(struct aml_resource_fixed_memory32),
48	ACPI_AML_SIZE_LARGE(struct aml_resource_address32),
49	ACPI_AML_SIZE_LARGE(struct aml_resource_address16),
50	ACPI_AML_SIZE_LARGE(struct aml_resource_extended_irq),
51	ACPI_AML_SIZE_LARGE(struct aml_resource_address64),
52	ACPI_AML_SIZE_LARGE(struct aml_resource_extended_address64),
53	ACPI_AML_SIZE_LARGE(struct aml_resource_gpio),
54	ACPI_AML_SIZE_LARGE(struct aml_resource_pin_function),
55	ACPI_AML_SIZE_LARGE(struct aml_resource_common_serialbus),
56	ACPI_AML_SIZE_LARGE(struct aml_resource_pin_config),
57	ACPI_AML_SIZE_LARGE(struct aml_resource_pin_group),
58	ACPI_AML_SIZE_LARGE(struct aml_resource_pin_group_function),
59	ACPI_AML_SIZE_LARGE(struct aml_resource_pin_group_config),
60};
61
62const u8 acpi_gbl_resource_aml_serial_bus_sizes[] = {
63	0,
64	ACPI_AML_SIZE_LARGE(struct aml_resource_i2c_serialbus),
65	ACPI_AML_SIZE_LARGE(struct aml_resource_spi_serialbus),
66	ACPI_AML_SIZE_LARGE(struct aml_resource_uart_serialbus),
67};
68
69/*
70 * Resource types, used to validate the resource length field.
71 * The length of fixed-length types must match exactly, variable
72 * lengths must meet the minimum required length, etc.
73 * Zero indicates a reserved (and therefore invalid) resource type.
74 */
75static const u8 acpi_gbl_resource_types[] = {
76	/* Small descriptors */
77
78	0,
79	0,
80	0,
81	0,
82	ACPI_SMALL_VARIABLE_LENGTH,	/* 04 IRQ */
83	ACPI_FIXED_LENGTH,	/* 05 DMA */
84	ACPI_SMALL_VARIABLE_LENGTH,	/* 06 start_dependent_functions */
85	ACPI_FIXED_LENGTH,	/* 07 end_dependent_functions */
86	ACPI_FIXED_LENGTH,	/* 08 IO */
87	ACPI_FIXED_LENGTH,	/* 09 fixed_IO */
88	ACPI_FIXED_LENGTH,	/* 0A fixed_DMA */
89	0,
90	0,
91	0,
92	ACPI_VARIABLE_LENGTH,	/* 0E vendor_short */
93	ACPI_FIXED_LENGTH,	/* 0F end_tag */
94
95	/* Large descriptors */
96
97	0,
98	ACPI_FIXED_LENGTH,	/* 01 Memory24 */
99	ACPI_FIXED_LENGTH,	/* 02 generic_register */
100	0,
101	ACPI_VARIABLE_LENGTH,	/* 04 vendor_long */
102	ACPI_FIXED_LENGTH,	/* 05 Memory32 */
103	ACPI_FIXED_LENGTH,	/* 06 memory32_fixed */
104	ACPI_VARIABLE_LENGTH,	/* 07 Dword* address */
105	ACPI_VARIABLE_LENGTH,	/* 08 Word* address */
106	ACPI_VARIABLE_LENGTH,	/* 09 extended_IRQ */
107	ACPI_VARIABLE_LENGTH,	/* 0A Qword* address */
108	ACPI_FIXED_LENGTH,	/* 0B Extended* address */
109	ACPI_VARIABLE_LENGTH,	/* 0C Gpio* */
110	ACPI_VARIABLE_LENGTH,	/* 0D pin_function */
111	ACPI_VARIABLE_LENGTH,	/* 0E *serial_bus */
112	ACPI_VARIABLE_LENGTH,	/* 0F pin_config */
113	ACPI_VARIABLE_LENGTH,	/* 10 pin_group */
114	ACPI_VARIABLE_LENGTH,	/* 11 pin_group_function */
115	ACPI_VARIABLE_LENGTH,	/* 12 pin_group_config */
116};
117
118/*******************************************************************************
119 *
120 * FUNCTION:    acpi_ut_walk_aml_resources
121 *
122 * PARAMETERS:  walk_state          - Current walk info
123 * PARAMETERS:  aml                 - Pointer to the raw AML resource template
124 *              aml_length          - Length of the entire template
125 *              user_function       - Called once for each descriptor found. If
126 *                                    NULL, a pointer to the end_tag is returned
127 *              context             - Passed to user_function
128 *
129 * RETURN:      Status
130 *
131 * DESCRIPTION: Walk a raw AML resource list(buffer). User function called
132 *              once for each resource found.
133 *
134 ******************************************************************************/
135
136acpi_status
137acpi_ut_walk_aml_resources(struct acpi_walk_state *walk_state,
138			   u8 *aml,
139			   acpi_size aml_length,
140			   acpi_walk_aml_callback user_function, void **context)
141{
142	acpi_status status;
143	u8 *end_aml;
144	u8 resource_index;
145	u32 length;
146	u32 offset = 0;
147	u8 end_tag[2] = { 0x79, 0x00 };
148
149	ACPI_FUNCTION_TRACE(ut_walk_aml_resources);
150
151	/* The absolute minimum resource template is one end_tag descriptor */
152
153	if (aml_length < sizeof(struct aml_resource_end_tag)) {
154		return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);
155	}
156
157	/* Point to the end of the resource template buffer */
158
159	end_aml = aml + aml_length;
160
161	/* Walk the byte list, abort on any invalid descriptor type or length */
162
163	while (aml < end_aml) {
164
165		/* Validate the Resource Type and Resource Length */
166
167		status =
168		    acpi_ut_validate_resource(walk_state, aml, &resource_index);
169		if (ACPI_FAILURE(status)) {
170			/*
171			 * Exit on failure. Cannot continue because the descriptor
172			 * length may be bogus also.
173			 */
174			return_ACPI_STATUS(status);
175		}
176
177		/* Get the length of this descriptor */
178
179		length = acpi_ut_get_descriptor_length(aml);
180
181		/* Invoke the user function */
182
183		if (user_function) {
184			status =
185			    user_function(aml, length, offset, resource_index,
186					  context);
187			if (ACPI_FAILURE(status)) {
188				return_ACPI_STATUS(status);
189			}
190		}
191
192		/* An end_tag descriptor terminates this resource template */
193
194		if (acpi_ut_get_resource_type(aml) ==
195		    ACPI_RESOURCE_NAME_END_TAG) {
196			/*
197			 * There must be at least one more byte in the buffer for
198			 * the 2nd byte of the end_tag
199			 */
200			if ((aml + 1) >= end_aml) {
201				return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);
202			}
203
204			/*
205			 * Don't attempt to perform any validation on the 2nd byte.
206			 * Although all known ASL compilers insert a zero for the 2nd
207			 * byte, it can also be a checksum (as per the ACPI spec),
208			 * and this is occasionally seen in the field. July 2017.
209			 */
210
211			/* Return the pointer to the end_tag if requested */
212
213			if (!user_function) {
214				*context = aml;
215			}
216
217			/* Normal exit */
218
219			return_ACPI_STATUS(AE_OK);
220		}
221
222		aml += length;
223		offset += length;
224	}
225
226	/* Did not find an end_tag descriptor */
227
228	if (user_function) {
229
230		/* Insert an end_tag anyway. acpi_rs_get_list_length always leaves room */
231
232		(void)acpi_ut_validate_resource(walk_state, end_tag,
233						&resource_index);
234		status =
235		    user_function(end_tag, 2, offset, resource_index, context);
236		if (ACPI_FAILURE(status)) {
237			return_ACPI_STATUS(status);
238		}
239	}
240
241	return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);
242}
243
244/*******************************************************************************
245 *
246 * FUNCTION:    acpi_ut_validate_resource
247 *
248 * PARAMETERS:  walk_state          - Current walk info
249 *              aml                 - Pointer to the raw AML resource descriptor
250 *              return_index        - Where the resource index is returned. NULL
251 *                                    if the index is not required.
252 *
253 * RETURN:      Status, and optionally the Index into the global resource tables
254 *
255 * DESCRIPTION: Validate an AML resource descriptor by checking the Resource
256 *              Type and Resource Length. Returns an index into the global
257 *              resource information/dispatch tables for later use.
258 *
259 ******************************************************************************/
260
261acpi_status
262acpi_ut_validate_resource(struct acpi_walk_state *walk_state,
263			  void *aml, u8 *return_index)
264{
265	union aml_resource *aml_resource;
266	u8 resource_type;
267	u8 resource_index;
268	acpi_rs_length resource_length;
269	acpi_rs_length minimum_resource_length;
270
271	ACPI_FUNCTION_ENTRY();
272
273	/*
274	 * 1) Validate the resource_type field (Byte 0)
275	 */
276	resource_type = ACPI_GET8(aml);
277
278	/*
279	 * Byte 0 contains the descriptor name (Resource Type)
280	 * Examine the large/small bit in the resource header
281	 */
282	if (resource_type & ACPI_RESOURCE_NAME_LARGE) {
283
284		/* Verify the large resource type (name) against the max */
285
286		if (resource_type > ACPI_RESOURCE_NAME_LARGE_MAX) {
287			goto invalid_resource;
288		}
289
290		/*
291		 * Large Resource Type -- bits 6:0 contain the name
292		 * Translate range 0x80-0x8B to index range 0x10-0x1B
293		 */
294		resource_index = (u8) (resource_type - 0x70);
295	} else {
296		/*
297		 * Small Resource Type -- bits 6:3 contain the name
298		 * Shift range to index range 0x00-0x0F
299		 */
300		resource_index = (u8)
301		    ((resource_type & ACPI_RESOURCE_NAME_SMALL_MASK) >> 3);
302	}
303
304	/*
305	 * Check validity of the resource type, via acpi_gbl_resource_types.
306	 * Zero indicates an invalid resource.
307	 */
308	if (!acpi_gbl_resource_types[resource_index]) {
309		goto invalid_resource;
310	}
311
312	/*
313	 * Validate the resource_length field. This ensures that the length
314	 * is at least reasonable, and guarantees that it is non-zero.
315	 */
316	resource_length = acpi_ut_get_resource_length(aml);
317	minimum_resource_length = acpi_gbl_resource_aml_sizes[resource_index];
318
319	/* Validate based upon the type of resource - fixed length or variable */
320
321	switch (acpi_gbl_resource_types[resource_index]) {
322	case ACPI_FIXED_LENGTH:
323
324		/* Fixed length resource, length must match exactly */
325
326		if (resource_length != minimum_resource_length) {
327			goto bad_resource_length;
328		}
329		break;
330
331	case ACPI_VARIABLE_LENGTH:
332
333		/* Variable length resource, length must be at least the minimum */
334
335		if (resource_length < minimum_resource_length) {
336			goto bad_resource_length;
337		}
338		break;
339
340	case ACPI_SMALL_VARIABLE_LENGTH:
341
342		/* Small variable length resource, length can be (Min) or (Min-1) */
343
344		if ((resource_length > minimum_resource_length) ||
345		    (resource_length < (minimum_resource_length - 1))) {
346			goto bad_resource_length;
347		}
348		break;
349
350	default:
351
352		/* Shouldn't happen (because of validation earlier), but be sure */
353
354		goto invalid_resource;
355	}
356
357	aml_resource = ACPI_CAST_PTR(union aml_resource, aml);
358	if (resource_type == ACPI_RESOURCE_NAME_SERIAL_BUS) {
359
360		/* Validate the bus_type field */
361
362		if ((aml_resource->common_serial_bus.type == 0) ||
363		    (aml_resource->common_serial_bus.type >
364		     AML_RESOURCE_MAX_SERIALBUSTYPE)) {
365			if (walk_state) {
366				ACPI_ERROR((AE_INFO,
367					    "Invalid/unsupported SerialBus resource descriptor: BusType 0x%2.2X",
368					    aml_resource->common_serial_bus.
369					    type));
370			}
371			return (AE_AML_INVALID_RESOURCE_TYPE);
372		}
373	}
374
375	/* Optionally return the resource table index */
376
377	if (return_index) {
378		*return_index = resource_index;
379	}
380
381	return (AE_OK);
382
383invalid_resource:
384
385	if (walk_state) {
386		ACPI_ERROR((AE_INFO,
387			    "Invalid/unsupported resource descriptor: Type 0x%2.2X",
388			    resource_type));
389	}
390	return (AE_AML_INVALID_RESOURCE_TYPE);
391
392bad_resource_length:
393
394	if (walk_state) {
395		ACPI_ERROR((AE_INFO,
396			    "Invalid resource descriptor length: Type "
397			    "0x%2.2X, Length 0x%4.4X, MinLength 0x%4.4X",
398			    resource_type, resource_length,
399			    minimum_resource_length));
400	}
401	return (AE_AML_BAD_RESOURCE_LENGTH);
402}
403
404/*******************************************************************************
405 *
406 * FUNCTION:    acpi_ut_get_resource_type
407 *
408 * PARAMETERS:  aml             - Pointer to the raw AML resource descriptor
409 *
410 * RETURN:      The Resource Type with no extraneous bits (except the
411 *              Large/Small descriptor bit -- this is left alone)
412 *
413 * DESCRIPTION: Extract the Resource Type/Name from the first byte of
414 *              a resource descriptor.
415 *
416 ******************************************************************************/
417
418u8 acpi_ut_get_resource_type(void *aml)
419{
420	ACPI_FUNCTION_ENTRY();
421
422	/*
423	 * Byte 0 contains the descriptor name (Resource Type)
424	 * Examine the large/small bit in the resource header
425	 */
426	if (ACPI_GET8(aml) & ACPI_RESOURCE_NAME_LARGE) {
427
428		/* Large Resource Type -- bits 6:0 contain the name */
429
430		return (ACPI_GET8(aml));
431	} else {
432		/* Small Resource Type -- bits 6:3 contain the name */
433
434		return ((u8) (ACPI_GET8(aml) & ACPI_RESOURCE_NAME_SMALL_MASK));
435	}
436}
437
438/*******************************************************************************
439 *
440 * FUNCTION:    acpi_ut_get_resource_length
441 *
442 * PARAMETERS:  aml             - Pointer to the raw AML resource descriptor
443 *
444 * RETURN:      Byte Length
445 *
446 * DESCRIPTION: Get the "Resource Length" of a raw AML descriptor. By
447 *              definition, this does not include the size of the descriptor
448 *              header or the length field itself.
449 *
450 ******************************************************************************/
451
452u16 acpi_ut_get_resource_length(void *aml)
453{
454	acpi_rs_length resource_length;
455
456	ACPI_FUNCTION_ENTRY();
457
458	/*
459	 * Byte 0 contains the descriptor name (Resource Type)
460	 * Examine the large/small bit in the resource header
461	 */
462	if (ACPI_GET8(aml) & ACPI_RESOURCE_NAME_LARGE) {
463
464		/* Large Resource type -- bytes 1-2 contain the 16-bit length */
465
466		ACPI_MOVE_16_TO_16(&resource_length, ACPI_ADD_PTR(u8, aml, 1));
467
468	} else {
469		/* Small Resource type -- bits 2:0 of byte 0 contain the length */
470
471		resource_length = (u16) (ACPI_GET8(aml) &
472					 ACPI_RESOURCE_NAME_SMALL_LENGTH_MASK);
473	}
474
475	return (resource_length);
476}
477
478/*******************************************************************************
479 *
480 * FUNCTION:    acpi_ut_get_resource_header_length
481 *
482 * PARAMETERS:  aml             - Pointer to the raw AML resource descriptor
483 *
484 * RETURN:      Length of the AML header (depends on large/small descriptor)
485 *
486 * DESCRIPTION: Get the length of the header for this resource.
487 *
488 ******************************************************************************/
489
490u8 acpi_ut_get_resource_header_length(void *aml)
491{
492	ACPI_FUNCTION_ENTRY();
493
494	/* Examine the large/small bit in the resource header */
495
496	if (ACPI_GET8(aml) & ACPI_RESOURCE_NAME_LARGE) {
497		return (sizeof(struct aml_resource_large_header));
498	} else {
499		return (sizeof(struct aml_resource_small_header));
500	}
501}
502
503/*******************************************************************************
504 *
505 * FUNCTION:    acpi_ut_get_descriptor_length
506 *
507 * PARAMETERS:  aml             - Pointer to the raw AML resource descriptor
508 *
509 * RETURN:      Byte length
510 *
511 * DESCRIPTION: Get the total byte length of a raw AML descriptor, including the
512 *              length of the descriptor header and the length field itself.
513 *              Used to walk descriptor lists.
514 *
515 ******************************************************************************/
516
517u32 acpi_ut_get_descriptor_length(void *aml)
518{
519	ACPI_FUNCTION_ENTRY();
520
521	/*
522	 * Get the Resource Length (does not include header length) and add
523	 * the header length (depends on if this is a small or large resource)
524	 */
525	return (acpi_ut_get_resource_length(aml) +
526		acpi_ut_get_resource_header_length(aml));
527}
528
529/*******************************************************************************
530 *
531 * FUNCTION:    acpi_ut_get_resource_end_tag
532 *
533 * PARAMETERS:  obj_desc        - The resource template buffer object
534 *              end_tag         - Where the pointer to the end_tag is returned
535 *
536 * RETURN:      Status, pointer to the end tag
537 *
538 * DESCRIPTION: Find the end_tag resource descriptor in an AML resource template
539 *              Note: allows a buffer length of zero.
540 *
541 ******************************************************************************/
542
543acpi_status
544acpi_ut_get_resource_end_tag(union acpi_operand_object *obj_desc, u8 **end_tag)
545{
546	acpi_status status;
547
548	ACPI_FUNCTION_TRACE(ut_get_resource_end_tag);
549
550	/* Allow a buffer length of zero */
551
552	if (!obj_desc->buffer.length) {
553		*end_tag = obj_desc->buffer.pointer;
554		return_ACPI_STATUS(AE_OK);
555	}
556
557	/* Validate the template and get a pointer to the end_tag */
558
559	status = acpi_ut_walk_aml_resources(NULL, obj_desc->buffer.pointer,
560					    obj_desc->buffer.length, NULL,
561					    (void **)end_tag);
562
563	return_ACPI_STATUS(status);
564}
565