xref: /openbmc/linux/drivers/acpi/acpica/utresrc.c (revision de6da33e)
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 	ACPI_AML_SIZE_LARGE(struct aml_resource_csi2_serialbus),
68 };
69 
70 /*
71  * Resource types, used to validate the resource length field.
72  * The length of fixed-length types must match exactly, variable
73  * lengths must meet the minimum required length, etc.
74  * Zero indicates a reserved (and therefore invalid) resource type.
75  */
76 static const u8 acpi_gbl_resource_types[] = {
77 	/* Small descriptors */
78 
79 	0,
80 	0,
81 	0,
82 	0,
83 	ACPI_SMALL_VARIABLE_LENGTH,	/* 04 IRQ */
84 	ACPI_FIXED_LENGTH,	/* 05 DMA */
85 	ACPI_SMALL_VARIABLE_LENGTH,	/* 06 start_dependent_functions */
86 	ACPI_FIXED_LENGTH,	/* 07 end_dependent_functions */
87 	ACPI_FIXED_LENGTH,	/* 08 IO */
88 	ACPI_FIXED_LENGTH,	/* 09 fixed_IO */
89 	ACPI_FIXED_LENGTH,	/* 0A fixed_DMA */
90 	0,
91 	0,
92 	0,
93 	ACPI_VARIABLE_LENGTH,	/* 0E vendor_short */
94 	ACPI_FIXED_LENGTH,	/* 0F end_tag */
95 
96 	/* Large descriptors */
97 
98 	0,
99 	ACPI_FIXED_LENGTH,	/* 01 Memory24 */
100 	ACPI_FIXED_LENGTH,	/* 02 generic_register */
101 	0,
102 	ACPI_VARIABLE_LENGTH,	/* 04 vendor_long */
103 	ACPI_FIXED_LENGTH,	/* 05 Memory32 */
104 	ACPI_FIXED_LENGTH,	/* 06 memory32_fixed */
105 	ACPI_VARIABLE_LENGTH,	/* 07 Dword* address */
106 	ACPI_VARIABLE_LENGTH,	/* 08 Word* address */
107 	ACPI_VARIABLE_LENGTH,	/* 09 extended_IRQ */
108 	ACPI_VARIABLE_LENGTH,	/* 0A Qword* address */
109 	ACPI_FIXED_LENGTH,	/* 0B Extended* address */
110 	ACPI_VARIABLE_LENGTH,	/* 0C Gpio* */
111 	ACPI_VARIABLE_LENGTH,	/* 0D pin_function */
112 	ACPI_VARIABLE_LENGTH,	/* 0E *serial_bus */
113 	ACPI_VARIABLE_LENGTH,	/* 0F pin_config */
114 	ACPI_VARIABLE_LENGTH,	/* 10 pin_group */
115 	ACPI_VARIABLE_LENGTH,	/* 11 pin_group_function */
116 	ACPI_VARIABLE_LENGTH,	/* 12 pin_group_config */
117 };
118 
119 /*******************************************************************************
120  *
121  * FUNCTION:    acpi_ut_walk_aml_resources
122  *
123  * PARAMETERS:  walk_state          - Current walk info
124  * PARAMETERS:  aml                 - Pointer to the raw AML resource template
125  *              aml_length          - Length of the entire template
126  *              user_function       - Called once for each descriptor found. If
127  *                                    NULL, a pointer to the end_tag is returned
128  *              context             - Passed to user_function
129  *
130  * RETURN:      Status
131  *
132  * DESCRIPTION: Walk a raw AML resource list(buffer). User function called
133  *              once for each resource found.
134  *
135  ******************************************************************************/
136 
137 acpi_status
138 acpi_ut_walk_aml_resources(struct acpi_walk_state *walk_state,
139 			   u8 *aml,
140 			   acpi_size aml_length,
141 			   acpi_walk_aml_callback user_function, void **context)
142 {
143 	acpi_status status;
144 	u8 *end_aml;
145 	u8 resource_index;
146 	u32 length;
147 	u32 offset = 0;
148 	u8 end_tag[2] = { 0x79, 0x00 };
149 
150 	ACPI_FUNCTION_TRACE(ut_walk_aml_resources);
151 
152 	/* The absolute minimum resource template is one end_tag descriptor */
153 
154 	if (aml_length < sizeof(struct aml_resource_end_tag)) {
155 		return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);
156 	}
157 
158 	/* Point to the end of the resource template buffer */
159 
160 	end_aml = aml + aml_length;
161 
162 	/* Walk the byte list, abort on any invalid descriptor type or length */
163 
164 	while (aml < end_aml) {
165 
166 		/* Validate the Resource Type and Resource Length */
167 
168 		status =
169 		    acpi_ut_validate_resource(walk_state, aml, &resource_index);
170 		if (ACPI_FAILURE(status)) {
171 			/*
172 			 * Exit on failure. Cannot continue because the descriptor
173 			 * length may be bogus also.
174 			 */
175 			return_ACPI_STATUS(status);
176 		}
177 
178 		/* Get the length of this descriptor */
179 
180 		length = acpi_ut_get_descriptor_length(aml);
181 
182 		/* Invoke the user function */
183 
184 		if (user_function) {
185 			status =
186 			    user_function(aml, length, offset, resource_index,
187 					  context);
188 			if (ACPI_FAILURE(status)) {
189 				return_ACPI_STATUS(status);
190 			}
191 		}
192 
193 		/* An end_tag descriptor terminates this resource template */
194 
195 		if (acpi_ut_get_resource_type(aml) ==
196 		    ACPI_RESOURCE_NAME_END_TAG) {
197 			/*
198 			 * There must be at least one more byte in the buffer for
199 			 * the 2nd byte of the end_tag
200 			 */
201 			if ((aml + 1) >= end_aml) {
202 				return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);
203 			}
204 
205 			/*
206 			 * Don't attempt to perform any validation on the 2nd byte.
207 			 * Although all known ASL compilers insert a zero for the 2nd
208 			 * byte, it can also be a checksum (as per the ACPI spec),
209 			 * and this is occasionally seen in the field. July 2017.
210 			 */
211 
212 			/* Return the pointer to the end_tag if requested */
213 
214 			if (!user_function) {
215 				*context = aml;
216 			}
217 
218 			/* Normal exit */
219 
220 			return_ACPI_STATUS(AE_OK);
221 		}
222 
223 		aml += length;
224 		offset += length;
225 	}
226 
227 	/* Did not find an end_tag descriptor */
228 
229 	if (user_function) {
230 
231 		/* Insert an end_tag anyway. acpi_rs_get_list_length always leaves room */
232 
233 		(void)acpi_ut_validate_resource(walk_state, end_tag,
234 						&resource_index);
235 		status =
236 		    user_function(end_tag, 2, offset, resource_index, context);
237 		if (ACPI_FAILURE(status)) {
238 			return_ACPI_STATUS(status);
239 		}
240 	}
241 
242 	return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);
243 }
244 
245 /*******************************************************************************
246  *
247  * FUNCTION:    acpi_ut_validate_resource
248  *
249  * PARAMETERS:  walk_state          - Current walk info
250  *              aml                 - Pointer to the raw AML resource descriptor
251  *              return_index        - Where the resource index is returned. NULL
252  *                                    if the index is not required.
253  *
254  * RETURN:      Status, and optionally the Index into the global resource tables
255  *
256  * DESCRIPTION: Validate an AML resource descriptor by checking the Resource
257  *              Type and Resource Length. Returns an index into the global
258  *              resource information/dispatch tables for later use.
259  *
260  ******************************************************************************/
261 
262 acpi_status
263 acpi_ut_validate_resource(struct acpi_walk_state *walk_state,
264 			  void *aml, u8 *return_index)
265 {
266 	union aml_resource *aml_resource;
267 	u8 resource_type;
268 	u8 resource_index;
269 	acpi_rs_length resource_length;
270 	acpi_rs_length minimum_resource_length;
271 
272 	ACPI_FUNCTION_ENTRY();
273 
274 	/*
275 	 * 1) Validate the resource_type field (Byte 0)
276 	 */
277 	resource_type = ACPI_GET8(aml);
278 
279 	/*
280 	 * Byte 0 contains the descriptor name (Resource Type)
281 	 * Examine the large/small bit in the resource header
282 	 */
283 	if (resource_type & ACPI_RESOURCE_NAME_LARGE) {
284 
285 		/* Verify the large resource type (name) against the max */
286 
287 		if (resource_type > ACPI_RESOURCE_NAME_LARGE_MAX) {
288 			goto invalid_resource;
289 		}
290 
291 		/*
292 		 * Large Resource Type -- bits 6:0 contain the name
293 		 * Translate range 0x80-0x8B to index range 0x10-0x1B
294 		 */
295 		resource_index = (u8) (resource_type - 0x70);
296 	} else {
297 		/*
298 		 * Small Resource Type -- bits 6:3 contain the name
299 		 * Shift range to index range 0x00-0x0F
300 		 */
301 		resource_index = (u8)
302 		    ((resource_type & ACPI_RESOURCE_NAME_SMALL_MASK) >> 3);
303 	}
304 
305 	/*
306 	 * Check validity of the resource type, via acpi_gbl_resource_types.
307 	 * Zero indicates an invalid resource.
308 	 */
309 	if (!acpi_gbl_resource_types[resource_index]) {
310 		goto invalid_resource;
311 	}
312 
313 	/*
314 	 * Validate the resource_length field. This ensures that the length
315 	 * is at least reasonable, and guarantees that it is non-zero.
316 	 */
317 	resource_length = acpi_ut_get_resource_length(aml);
318 	minimum_resource_length = acpi_gbl_resource_aml_sizes[resource_index];
319 
320 	/* Validate based upon the type of resource - fixed length or variable */
321 
322 	switch (acpi_gbl_resource_types[resource_index]) {
323 	case ACPI_FIXED_LENGTH:
324 
325 		/* Fixed length resource, length must match exactly */
326 
327 		if (resource_length != minimum_resource_length) {
328 			goto bad_resource_length;
329 		}
330 		break;
331 
332 	case ACPI_VARIABLE_LENGTH:
333 
334 		/* Variable length resource, length must be at least the minimum */
335 
336 		if (resource_length < minimum_resource_length) {
337 			goto bad_resource_length;
338 		}
339 		break;
340 
341 	case ACPI_SMALL_VARIABLE_LENGTH:
342 
343 		/* Small variable length resource, length can be (Min) or (Min-1) */
344 
345 		if ((resource_length > minimum_resource_length) ||
346 		    (resource_length < (minimum_resource_length - 1))) {
347 			goto bad_resource_length;
348 		}
349 		break;
350 
351 	default:
352 
353 		/* Shouldn't happen (because of validation earlier), but be sure */
354 
355 		goto invalid_resource;
356 	}
357 
358 	aml_resource = ACPI_CAST_PTR(union aml_resource, aml);
359 	if (resource_type == ACPI_RESOURCE_NAME_SERIAL_BUS) {
360 
361 		/* Validate the bus_type field */
362 
363 		if ((aml_resource->common_serial_bus.type == 0) ||
364 		    (aml_resource->common_serial_bus.type >
365 		     AML_RESOURCE_MAX_SERIALBUSTYPE)) {
366 			if (walk_state) {
367 				ACPI_ERROR((AE_INFO,
368 					    "Invalid/unsupported SerialBus resource descriptor: BusType 0x%2.2X",
369 					    aml_resource->common_serial_bus.
370 					    type));
371 			}
372 			return (AE_AML_INVALID_RESOURCE_TYPE);
373 		}
374 	}
375 
376 	/* Optionally return the resource table index */
377 
378 	if (return_index) {
379 		*return_index = resource_index;
380 	}
381 
382 	return (AE_OK);
383 
384 invalid_resource:
385 
386 	if (walk_state) {
387 		ACPI_ERROR((AE_INFO,
388 			    "Invalid/unsupported resource descriptor: Type 0x%2.2X",
389 			    resource_type));
390 	}
391 	return (AE_AML_INVALID_RESOURCE_TYPE);
392 
393 bad_resource_length:
394 
395 	if (walk_state) {
396 		ACPI_ERROR((AE_INFO,
397 			    "Invalid resource descriptor length: Type "
398 			    "0x%2.2X, Length 0x%4.4X, MinLength 0x%4.4X",
399 			    resource_type, resource_length,
400 			    minimum_resource_length));
401 	}
402 	return (AE_AML_BAD_RESOURCE_LENGTH);
403 }
404 
405 /*******************************************************************************
406  *
407  * FUNCTION:    acpi_ut_get_resource_type
408  *
409  * PARAMETERS:  aml             - Pointer to the raw AML resource descriptor
410  *
411  * RETURN:      The Resource Type with no extraneous bits (except the
412  *              Large/Small descriptor bit -- this is left alone)
413  *
414  * DESCRIPTION: Extract the Resource Type/Name from the first byte of
415  *              a resource descriptor.
416  *
417  ******************************************************************************/
418 
419 u8 acpi_ut_get_resource_type(void *aml)
420 {
421 	ACPI_FUNCTION_ENTRY();
422 
423 	/*
424 	 * Byte 0 contains the descriptor name (Resource Type)
425 	 * Examine the large/small bit in the resource header
426 	 */
427 	if (ACPI_GET8(aml) & ACPI_RESOURCE_NAME_LARGE) {
428 
429 		/* Large Resource Type -- bits 6:0 contain the name */
430 
431 		return (ACPI_GET8(aml));
432 	} else {
433 		/* Small Resource Type -- bits 6:3 contain the name */
434 
435 		return ((u8) (ACPI_GET8(aml) & ACPI_RESOURCE_NAME_SMALL_MASK));
436 	}
437 }
438 
439 /*******************************************************************************
440  *
441  * FUNCTION:    acpi_ut_get_resource_length
442  *
443  * PARAMETERS:  aml             - Pointer to the raw AML resource descriptor
444  *
445  * RETURN:      Byte Length
446  *
447  * DESCRIPTION: Get the "Resource Length" of a raw AML descriptor. By
448  *              definition, this does not include the size of the descriptor
449  *              header or the length field itself.
450  *
451  ******************************************************************************/
452 
453 u16 acpi_ut_get_resource_length(void *aml)
454 {
455 	acpi_rs_length resource_length;
456 
457 	ACPI_FUNCTION_ENTRY();
458 
459 	/*
460 	 * Byte 0 contains the descriptor name (Resource Type)
461 	 * Examine the large/small bit in the resource header
462 	 */
463 	if (ACPI_GET8(aml) & ACPI_RESOURCE_NAME_LARGE) {
464 
465 		/* Large Resource type -- bytes 1-2 contain the 16-bit length */
466 
467 		ACPI_MOVE_16_TO_16(&resource_length, ACPI_ADD_PTR(u8, aml, 1));
468 
469 	} else {
470 		/* Small Resource type -- bits 2:0 of byte 0 contain the length */
471 
472 		resource_length = (u16) (ACPI_GET8(aml) &
473 					 ACPI_RESOURCE_NAME_SMALL_LENGTH_MASK);
474 	}
475 
476 	return (resource_length);
477 }
478 
479 /*******************************************************************************
480  *
481  * FUNCTION:    acpi_ut_get_resource_header_length
482  *
483  * PARAMETERS:  aml             - Pointer to the raw AML resource descriptor
484  *
485  * RETURN:      Length of the AML header (depends on large/small descriptor)
486  *
487  * DESCRIPTION: Get the length of the header for this resource.
488  *
489  ******************************************************************************/
490 
491 u8 acpi_ut_get_resource_header_length(void *aml)
492 {
493 	ACPI_FUNCTION_ENTRY();
494 
495 	/* Examine the large/small bit in the resource header */
496 
497 	if (ACPI_GET8(aml) & ACPI_RESOURCE_NAME_LARGE) {
498 		return (sizeof(struct aml_resource_large_header));
499 	} else {
500 		return (sizeof(struct aml_resource_small_header));
501 	}
502 }
503 
504 /*******************************************************************************
505  *
506  * FUNCTION:    acpi_ut_get_descriptor_length
507  *
508  * PARAMETERS:  aml             - Pointer to the raw AML resource descriptor
509  *
510  * RETURN:      Byte length
511  *
512  * DESCRIPTION: Get the total byte length of a raw AML descriptor, including the
513  *              length of the descriptor header and the length field itself.
514  *              Used to walk descriptor lists.
515  *
516  ******************************************************************************/
517 
518 u32 acpi_ut_get_descriptor_length(void *aml)
519 {
520 	ACPI_FUNCTION_ENTRY();
521 
522 	/*
523 	 * Get the Resource Length (does not include header length) and add
524 	 * the header length (depends on if this is a small or large resource)
525 	 */
526 	return (acpi_ut_get_resource_length(aml) +
527 		acpi_ut_get_resource_header_length(aml));
528 }
529 
530 /*******************************************************************************
531  *
532  * FUNCTION:    acpi_ut_get_resource_end_tag
533  *
534  * PARAMETERS:  obj_desc        - The resource template buffer object
535  *              end_tag         - Where the pointer to the end_tag is returned
536  *
537  * RETURN:      Status, pointer to the end tag
538  *
539  * DESCRIPTION: Find the end_tag resource descriptor in an AML resource template
540  *              Note: allows a buffer length of zero.
541  *
542  ******************************************************************************/
543 
544 acpi_status
545 acpi_ut_get_resource_end_tag(union acpi_operand_object *obj_desc, u8 **end_tag)
546 {
547 	acpi_status status;
548 
549 	ACPI_FUNCTION_TRACE(ut_get_resource_end_tag);
550 
551 	/* Allow a buffer length of zero */
552 
553 	if (!obj_desc->buffer.length) {
554 		*end_tag = obj_desc->buffer.pointer;
555 		return_ACPI_STATUS(AE_OK);
556 	}
557 
558 	/* Validate the template and get a pointer to the end_tag */
559 
560 	status = acpi_ut_walk_aml_resources(NULL, obj_desc->buffer.pointer,
561 					    obj_desc->buffer.length, NULL,
562 					    (void **)end_tag);
563 
564 	return_ACPI_STATUS(status);
565 }
566