xref: /openbmc/linux/drivers/acpi/acpica/exconvrt.c (revision 9a29f5fc)
1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /******************************************************************************
3  *
4  * Module Name: exconvrt - Object conversion routines
5  *
6  * Copyright (C) 2000 - 2022, Intel Corp.
7  *
8  *****************************************************************************/
9 
10 #include <acpi/acpi.h>
11 #include "accommon.h"
12 #include "acinterp.h"
13 #include "amlcode.h"
14 
15 #define _COMPONENT          ACPI_EXECUTER
16 ACPI_MODULE_NAME("exconvrt")
17 
18 /* Local prototypes */
19 static u32
20 acpi_ex_convert_to_ascii(u64 integer, u16 base, u8 *string, u8 max_length);
21 
22 /*******************************************************************************
23  *
24  * FUNCTION:    acpi_ex_convert_to_integer
25  *
26  * PARAMETERS:  obj_desc            - Object to be converted. Must be an
27  *                                    Integer, Buffer, or String
28  *              result_desc         - Where the new Integer object is returned
29  *              implicit_conversion - Used for string conversion
30  *
31  * RETURN:      Status
32  *
33  * DESCRIPTION: Convert an ACPI Object to an integer.
34  *
35  ******************************************************************************/
36 
37 acpi_status
38 acpi_ex_convert_to_integer(union acpi_operand_object *obj_desc,
39 			   union acpi_operand_object **result_desc,
40 			   u32 implicit_conversion)
41 {
42 	union acpi_operand_object *return_desc;
43 	u8 *pointer;
44 	u64 result;
45 	u32 i;
46 	u32 count;
47 
48 	ACPI_FUNCTION_TRACE_PTR(ex_convert_to_integer, obj_desc);
49 
50 	switch (obj_desc->common.type) {
51 	case ACPI_TYPE_INTEGER:
52 
53 		/* No conversion necessary */
54 
55 		*result_desc = obj_desc;
56 		return_ACPI_STATUS(AE_OK);
57 
58 	case ACPI_TYPE_BUFFER:
59 	case ACPI_TYPE_STRING:
60 
61 		/* Note: Takes advantage of common buffer/string fields */
62 
63 		pointer = obj_desc->buffer.pointer;
64 		count = obj_desc->buffer.length;
65 		break;
66 
67 	default:
68 
69 		return_ACPI_STATUS(AE_TYPE);
70 	}
71 
72 	/*
73 	 * Convert the buffer/string to an integer. Note that both buffers and
74 	 * strings are treated as raw data - we don't convert ascii to hex for
75 	 * strings.
76 	 *
77 	 * There are two terminating conditions for the loop:
78 	 * 1) The size of an integer has been reached, or
79 	 * 2) The end of the buffer or string has been reached
80 	 */
81 	result = 0;
82 
83 	/* String conversion is different than Buffer conversion */
84 
85 	switch (obj_desc->common.type) {
86 	case ACPI_TYPE_STRING:
87 		/*
88 		 * Convert string to an integer - for most cases, the string must be
89 		 * hexadecimal as per the ACPI specification. The only exception (as
90 		 * of ACPI 3.0) is that the to_integer() operator allows both decimal
91 		 * and hexadecimal strings (hex prefixed with "0x").
92 		 *
93 		 * Explicit conversion is used only by to_integer.
94 		 * All other string-to-integer conversions are implicit conversions.
95 		 */
96 		if (implicit_conversion) {
97 			result =
98 			    acpi_ut_implicit_strtoul64(ACPI_CAST_PTR
99 						       (char, pointer));
100 		} else {
101 			result =
102 			    acpi_ut_explicit_strtoul64(ACPI_CAST_PTR
103 						       (char, pointer));
104 		}
105 		break;
106 
107 	case ACPI_TYPE_BUFFER:
108 
109 		/* Check for zero-length buffer */
110 
111 		if (!count) {
112 			return_ACPI_STATUS(AE_AML_BUFFER_LIMIT);
113 		}
114 
115 		/* Transfer no more than an integer's worth of data */
116 
117 		if (count > acpi_gbl_integer_byte_width) {
118 			count = acpi_gbl_integer_byte_width;
119 		}
120 
121 		/*
122 		 * Convert buffer to an integer - we simply grab enough raw data
123 		 * from the buffer to fill an integer
124 		 */
125 		for (i = 0; i < count; i++) {
126 			/*
127 			 * Get next byte and shift it into the Result.
128 			 * Little endian is used, meaning that the first byte of the buffer
129 			 * is the LSB of the integer
130 			 */
131 			result |= (((u64) pointer[i]) << (i * 8));
132 		}
133 		break;
134 
135 	default:
136 
137 		/* No other types can get here */
138 
139 		break;
140 	}
141 
142 	/* Create a new integer */
143 
144 	return_desc = acpi_ut_create_integer_object(result);
145 	if (!return_desc) {
146 		return_ACPI_STATUS(AE_NO_MEMORY);
147 	}
148 
149 	ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Converted value: %8.8X%8.8X\n",
150 			  ACPI_FORMAT_UINT64(result)));
151 
152 	/* Save the Result */
153 
154 	(void)acpi_ex_truncate_for32bit_table(return_desc);
155 	*result_desc = return_desc;
156 	return_ACPI_STATUS(AE_OK);
157 }
158 
159 /*******************************************************************************
160  *
161  * FUNCTION:    acpi_ex_convert_to_buffer
162  *
163  * PARAMETERS:  obj_desc        - Object to be converted. Must be an
164  *                                Integer, Buffer, or String
165  *              result_desc     - Where the new buffer object is returned
166  *
167  * RETURN:      Status
168  *
169  * DESCRIPTION: Convert an ACPI Object to a Buffer
170  *
171  ******************************************************************************/
172 
173 acpi_status
174 acpi_ex_convert_to_buffer(union acpi_operand_object *obj_desc,
175 			  union acpi_operand_object **result_desc)
176 {
177 	union acpi_operand_object *return_desc;
178 	u8 *new_buf;
179 
180 	ACPI_FUNCTION_TRACE_PTR(ex_convert_to_buffer, obj_desc);
181 
182 	switch (obj_desc->common.type) {
183 	case ACPI_TYPE_BUFFER:
184 
185 		/* No conversion necessary */
186 
187 		*result_desc = obj_desc;
188 		return_ACPI_STATUS(AE_OK);
189 
190 	case ACPI_TYPE_INTEGER:
191 		/*
192 		 * Create a new Buffer object.
193 		 * Need enough space for one integer
194 		 */
195 		return_desc =
196 		    acpi_ut_create_buffer_object(acpi_gbl_integer_byte_width);
197 		if (!return_desc) {
198 			return_ACPI_STATUS(AE_NO_MEMORY);
199 		}
200 
201 		/* Copy the integer to the buffer, LSB first */
202 
203 		new_buf = return_desc->buffer.pointer;
204 		memcpy(new_buf, &obj_desc->integer.value,
205 		       acpi_gbl_integer_byte_width);
206 		break;
207 
208 	case ACPI_TYPE_STRING:
209 		/*
210 		 * Create a new Buffer object
211 		 * Size will be the string length
212 		 *
213 		 * NOTE: Add one to the string length to include the null terminator.
214 		 * The ACPI spec is unclear on this subject, but there is existing
215 		 * ASL/AML code that depends on the null being transferred to the new
216 		 * buffer.
217 		 */
218 		return_desc = acpi_ut_create_buffer_object((acpi_size)
219 							   obj_desc->string.
220 							   length + 1);
221 		if (!return_desc) {
222 			return_ACPI_STATUS(AE_NO_MEMORY);
223 		}
224 
225 		/* Copy the string to the buffer */
226 
227 		new_buf = return_desc->buffer.pointer;
228 		strncpy((char *)new_buf, (char *)obj_desc->string.pointer,
229 			obj_desc->string.length);
230 		break;
231 
232 	default:
233 
234 		return_ACPI_STATUS(AE_TYPE);
235 	}
236 
237 	/* Mark buffer initialized */
238 
239 	return_desc->common.flags |= AOPOBJ_DATA_VALID;
240 	*result_desc = return_desc;
241 	return_ACPI_STATUS(AE_OK);
242 }
243 
244 /*******************************************************************************
245  *
246  * FUNCTION:    acpi_ex_convert_to_ascii
247  *
248  * PARAMETERS:  integer         - Value to be converted
249  *              base            - ACPI_STRING_DECIMAL or ACPI_STRING_HEX
250  *              string          - Where the string is returned
251  *              data_width      - Size of data item to be converted, in bytes
252  *
253  * RETURN:      Actual string length
254  *
255  * DESCRIPTION: Convert an ACPI Integer to a hex or decimal string
256  *
257  ******************************************************************************/
258 
259 static u32
260 acpi_ex_convert_to_ascii(u64 integer, u16 base, u8 *string, u8 data_width)
261 {
262 	u64 digit;
263 	u32 i;
264 	u32 j;
265 	u32 k = 0;
266 	u32 hex_length;
267 	u32 decimal_length;
268 	u32 remainder;
269 	u8 supress_zeros;
270 
271 	ACPI_FUNCTION_ENTRY();
272 
273 	switch (base) {
274 	case 10:
275 
276 		/* Setup max length for the decimal number */
277 
278 		switch (data_width) {
279 		case 1:
280 
281 			decimal_length = ACPI_MAX8_DECIMAL_DIGITS;
282 			break;
283 
284 		case 4:
285 
286 			decimal_length = ACPI_MAX32_DECIMAL_DIGITS;
287 			break;
288 
289 		case 8:
290 		default:
291 
292 			decimal_length = ACPI_MAX64_DECIMAL_DIGITS;
293 			break;
294 		}
295 
296 		supress_zeros = TRUE;	/* No leading zeros */
297 		remainder = 0;
298 
299 		for (i = decimal_length; i > 0; i--) {
300 
301 			/* Divide by nth factor of 10 */
302 
303 			digit = integer;
304 			for (j = 0; j < i; j++) {
305 				(void)acpi_ut_short_divide(digit, 10, &digit,
306 							   &remainder);
307 			}
308 
309 			/* Handle leading zeros */
310 
311 			if (remainder != 0) {
312 				supress_zeros = FALSE;
313 			}
314 
315 			if (!supress_zeros) {
316 				string[k] = (u8) (ACPI_ASCII_ZERO + remainder);
317 				k++;
318 			}
319 		}
320 		break;
321 
322 	case 16:
323 
324 		/* hex_length: 2 ascii hex chars per data byte */
325 
326 		hex_length = (data_width * 2);
327 		for (i = 0, j = (hex_length - 1); i < hex_length; i++, j--) {
328 
329 			/* Get one hex digit, most significant digits first */
330 
331 			string[k] = (u8)
332 			    acpi_ut_hex_to_ascii_char(integer, ACPI_MUL_4(j));
333 			k++;
334 		}
335 		break;
336 
337 	default:
338 		return (0);
339 	}
340 
341 	/*
342 	 * Since leading zeros are suppressed, we must check for the case where
343 	 * the integer equals 0
344 	 *
345 	 * Finally, null terminate the string and return the length
346 	 */
347 	if (!k) {
348 		string[0] = ACPI_ASCII_ZERO;
349 		k = 1;
350 	}
351 
352 	string[k] = 0;
353 	return ((u32) k);
354 }
355 
356 /*******************************************************************************
357  *
358  * FUNCTION:    acpi_ex_convert_to_string
359  *
360  * PARAMETERS:  obj_desc        - Object to be converted. Must be an
361  *                                Integer, Buffer, or String
362  *              result_desc     - Where the string object is returned
363  *              type            - String flags (base and conversion type)
364  *
365  * RETURN:      Status
366  *
367  * DESCRIPTION: Convert an ACPI Object to a string. Supports both implicit
368  *              and explicit conversions and related rules.
369  *
370  ******************************************************************************/
371 
372 acpi_status
373 acpi_ex_convert_to_string(union acpi_operand_object * obj_desc,
374 			  union acpi_operand_object ** result_desc, u32 type)
375 {
376 	union acpi_operand_object *return_desc;
377 	u8 *new_buf;
378 	u32 i;
379 	u32 string_length = 0;
380 	u16 base = 16;
381 	u8 separator = ',';
382 
383 	ACPI_FUNCTION_TRACE_PTR(ex_convert_to_string, obj_desc);
384 
385 	switch (obj_desc->common.type) {
386 	case ACPI_TYPE_STRING:
387 
388 		/* No conversion necessary */
389 
390 		*result_desc = obj_desc;
391 		return_ACPI_STATUS(AE_OK);
392 
393 	case ACPI_TYPE_INTEGER:
394 
395 		switch (type) {
396 		case ACPI_EXPLICIT_CONVERT_DECIMAL:
397 			/*
398 			 * From to_decimal_string, integer source.
399 			 *
400 			 * Make room for the maximum decimal number size
401 			 */
402 			string_length = ACPI_MAX_DECIMAL_DIGITS;
403 			base = 10;
404 			break;
405 
406 		default:
407 
408 			/* Two hex string characters for each integer byte */
409 
410 			string_length = ACPI_MUL_2(acpi_gbl_integer_byte_width);
411 			break;
412 		}
413 
414 		/*
415 		 * Create a new String
416 		 * Need enough space for one ASCII integer (plus null terminator)
417 		 */
418 		return_desc =
419 		    acpi_ut_create_string_object((acpi_size)string_length);
420 		if (!return_desc) {
421 			return_ACPI_STATUS(AE_NO_MEMORY);
422 		}
423 
424 		new_buf = return_desc->buffer.pointer;
425 
426 		/* Convert integer to string */
427 
428 		string_length =
429 		    acpi_ex_convert_to_ascii(obj_desc->integer.value, base,
430 					     new_buf,
431 					     acpi_gbl_integer_byte_width);
432 
433 		/* Null terminate at the correct place */
434 
435 		return_desc->string.length = string_length;
436 		new_buf[string_length] = 0;
437 		break;
438 
439 	case ACPI_TYPE_BUFFER:
440 
441 		/* Setup string length, base, and separator */
442 
443 		switch (type) {
444 		case ACPI_EXPLICIT_CONVERT_DECIMAL:	/* Used by to_decimal_string */
445 			/*
446 			 * Explicit conversion from the to_decimal_string ASL operator.
447 			 *
448 			 * From ACPI: "If the input is a buffer, it is converted to a
449 			 * a string of decimal values separated by commas."
450 			 */
451 			base = 10;
452 
453 			/*
454 			 * Calculate the final string length. Individual string values
455 			 * are variable length (include separator for each)
456 			 */
457 			for (i = 0; i < obj_desc->buffer.length; i++) {
458 				if (obj_desc->buffer.pointer[i] >= 100) {
459 					string_length += 4;
460 				} else if (obj_desc->buffer.pointer[i] >= 10) {
461 					string_length += 3;
462 				} else {
463 					string_length += 2;
464 				}
465 			}
466 			break;
467 
468 		case ACPI_IMPLICIT_CONVERT_HEX:
469 			/*
470 			 * Implicit buffer-to-string conversion
471 			 *
472 			 * From the ACPI spec:
473 			 * "The entire contents of the buffer are converted to a string of
474 			 * two-character hexadecimal numbers, each separated by a space."
475 			 *
476 			 * Each hex number is prefixed with 0x (11/2018)
477 			 */
478 			separator = ' ';
479 			string_length = (obj_desc->buffer.length * 5);
480 			break;
481 
482 		case ACPI_EXPLICIT_CONVERT_HEX:
483 			/*
484 			 * Explicit conversion from the to_hex_string ASL operator.
485 			 *
486 			 * From ACPI: "If Data is a buffer, it is converted to a string of
487 			 * hexadecimal values separated by commas."
488 			 *
489 			 * Each hex number is prefixed with 0x (11/2018)
490 			 */
491 			separator = ',';
492 			string_length = (obj_desc->buffer.length * 5);
493 			break;
494 
495 		default:
496 			return_ACPI_STATUS(AE_BAD_PARAMETER);
497 		}
498 
499 		/*
500 		 * Create a new string object and string buffer
501 		 * (-1 because of extra separator included in string_length from above)
502 		 * Allow creation of zero-length strings from zero-length buffers.
503 		 */
504 		if (string_length) {
505 			string_length--;
506 		}
507 
508 		return_desc =
509 		    acpi_ut_create_string_object((acpi_size)string_length);
510 		if (!return_desc) {
511 			return_ACPI_STATUS(AE_NO_MEMORY);
512 		}
513 
514 		new_buf = return_desc->buffer.pointer;
515 
516 		/*
517 		 * Convert buffer bytes to hex or decimal values
518 		 * (separated by commas or spaces)
519 		 */
520 		for (i = 0; i < obj_desc->buffer.length; i++) {
521 			if (base == 16) {
522 
523 				/* Emit 0x prefix for explicit/implicit hex conversion */
524 
525 				*new_buf++ = '0';
526 				*new_buf++ = 'x';
527 			}
528 
529 			new_buf += acpi_ex_convert_to_ascii((u64) obj_desc->
530 							    buffer.pointer[i],
531 							    base, new_buf, 1);
532 
533 			/* Each digit is separated by either a comma or space */
534 
535 			*new_buf++ = separator;
536 		}
537 
538 		/*
539 		 * Null terminate the string
540 		 * (overwrites final comma/space from above)
541 		 */
542 		if (obj_desc->buffer.length) {
543 			new_buf--;
544 		}
545 		*new_buf = 0;
546 		break;
547 
548 	default:
549 
550 		return_ACPI_STATUS(AE_TYPE);
551 	}
552 
553 	*result_desc = return_desc;
554 	return_ACPI_STATUS(AE_OK);
555 }
556 
557 /*******************************************************************************
558  *
559  * FUNCTION:    acpi_ex_convert_to_target_type
560  *
561  * PARAMETERS:  destination_type    - Current type of the destination
562  *              source_desc         - Source object to be converted.
563  *              result_desc         - Where the converted object is returned
564  *              walk_state          - Current method state
565  *
566  * RETURN:      Status
567  *
568  * DESCRIPTION: Implements "implicit conversion" rules for storing an object.
569  *
570  ******************************************************************************/
571 
572 acpi_status
573 acpi_ex_convert_to_target_type(acpi_object_type destination_type,
574 			       union acpi_operand_object *source_desc,
575 			       union acpi_operand_object **result_desc,
576 			       struct acpi_walk_state *walk_state)
577 {
578 	acpi_status status = AE_OK;
579 
580 	ACPI_FUNCTION_TRACE(ex_convert_to_target_type);
581 
582 	/* Default behavior */
583 
584 	*result_desc = source_desc;
585 
586 	/*
587 	 * If required by the target,
588 	 * perform implicit conversion on the source before we store it.
589 	 */
590 	switch (GET_CURRENT_ARG_TYPE(walk_state->op_info->runtime_args)) {
591 	case ARGI_SIMPLE_TARGET:
592 	case ARGI_FIXED_TARGET:
593 	case ARGI_INTEGER_REF:	/* Handles Increment, Decrement cases */
594 
595 		switch (destination_type) {
596 		case ACPI_TYPE_LOCAL_REGION_FIELD:
597 			/*
598 			 * Named field can always handle conversions
599 			 */
600 			break;
601 
602 		default:
603 
604 			/* No conversion allowed for these types */
605 
606 			if (destination_type != source_desc->common.type) {
607 				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
608 						  "Explicit operator, will store (%s) over existing type (%s)\n",
609 						  acpi_ut_get_object_type_name
610 						  (source_desc),
611 						  acpi_ut_get_type_name
612 						  (destination_type)));
613 				status = AE_TYPE;
614 			}
615 		}
616 		break;
617 
618 	case ARGI_TARGETREF:
619 	case ARGI_STORE_TARGET:
620 
621 		switch (destination_type) {
622 		case ACPI_TYPE_INTEGER:
623 		case ACPI_TYPE_BUFFER_FIELD:
624 		case ACPI_TYPE_LOCAL_BANK_FIELD:
625 		case ACPI_TYPE_LOCAL_INDEX_FIELD:
626 			/*
627 			 * These types require an Integer operand. We can convert
628 			 * a Buffer or a String to an Integer if necessary.
629 			 */
630 			status =
631 			    acpi_ex_convert_to_integer(source_desc, result_desc,
632 						       ACPI_IMPLICIT_CONVERSION);
633 			break;
634 
635 		case ACPI_TYPE_STRING:
636 			/*
637 			 * The operand must be a String. We can convert an
638 			 * Integer or Buffer if necessary
639 			 */
640 			status =
641 			    acpi_ex_convert_to_string(source_desc, result_desc,
642 						      ACPI_IMPLICIT_CONVERT_HEX);
643 			break;
644 
645 		case ACPI_TYPE_BUFFER:
646 			/*
647 			 * The operand must be a Buffer. We can convert an
648 			 * Integer or String if necessary
649 			 */
650 			status =
651 			    acpi_ex_convert_to_buffer(source_desc, result_desc);
652 			break;
653 
654 		default:
655 
656 			ACPI_ERROR((AE_INFO,
657 				    "Bad destination type during conversion: 0x%X",
658 				    destination_type));
659 			status = AE_AML_INTERNAL;
660 			break;
661 		}
662 		break;
663 
664 	case ARGI_REFERENCE:
665 		/*
666 		 * create_xxxx_field cases - we are storing the field object into the name
667 		 */
668 		break;
669 
670 	default:
671 
672 		ACPI_ERROR((AE_INFO,
673 			    "Unknown Target type ID 0x%X AmlOpcode 0x%X DestType %s",
674 			    GET_CURRENT_ARG_TYPE(walk_state->op_info->
675 						 runtime_args),
676 			    walk_state->opcode,
677 			    acpi_ut_get_type_name(destination_type)));
678 		status = AE_AML_INTERNAL;
679 	}
680 
681 	/*
682 	 * Source-to-Target conversion semantics:
683 	 *
684 	 * If conversion to the target type cannot be performed, then simply
685 	 * overwrite the target with the new object and type.
686 	 */
687 	if (status == AE_TYPE) {
688 		status = AE_OK;
689 	}
690 
691 	return_ACPI_STATUS(status);
692 }
693