xref: /linux/drivers/acpi/acpica/utresrc.c (revision ca853314e78b0a65c20b6a889a23c31f918d4aa2)
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
13 ACPI_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  */
19 const 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 
62 const 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  */
75 static 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 
136 acpi_status
137 acpi_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 
261 acpi_status
262 acpi_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 
383 invalid_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 
392 bad_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 
418 u8 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 
452 u16 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 
490 u8 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 
517 u32 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 
543 acpi_status
544 acpi_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