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[pohmelfs.git] / drivers / acpi / acpica / exfldio.c
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1 /******************************************************************************
3 * Module Name: exfldio - Aml Field I/O
5 *****************************************************************************/
7 /*
8 * Copyright (C) 2000 - 2012, Intel Corp.
9 * All rights reserved.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions, and the following disclaimer,
16 * without modification.
17 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18 * substantially similar to the "NO WARRANTY" disclaimer below
19 * ("Disclaimer") and any redistribution must be conditioned upon
20 * including a substantially similar Disclaimer requirement for further
21 * binary redistribution.
22 * 3. Neither the names of the above-listed copyright holders nor the names
23 * of any contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
26 * Alternatively, this software may be distributed under the terms of the
27 * GNU General Public License ("GPL") version 2 as published by the Free
28 * Software Foundation.
30 * NO WARRANTY
31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41 * POSSIBILITY OF SUCH DAMAGES.
44 #include <acpi/acpi.h>
45 #include "accommon.h"
46 #include "acinterp.h"
47 #include "amlcode.h"
48 #include "acevents.h"
49 #include "acdispat.h"
51 #define _COMPONENT ACPI_EXECUTER
52 ACPI_MODULE_NAME("exfldio")
54 /* Local prototypes */
55 static acpi_status
56 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
57 u32 field_datum_byte_offset,
58 u64 *value, u32 read_write);
60 static u8
61 acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 value);
63 static acpi_status
64 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
65 u32 field_datum_byte_offset);
67 /*******************************************************************************
69 * FUNCTION: acpi_ex_setup_region
71 * PARAMETERS: obj_desc - Field to be read or written
72 * field_datum_byte_offset - Byte offset of this datum within the
73 * parent field
75 * RETURN: Status
77 * DESCRIPTION: Common processing for acpi_ex_extract_from_field and
78 * acpi_ex_insert_into_field. Initialize the Region if necessary and
79 * validate the request.
81 ******************************************************************************/
83 static acpi_status
84 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
85 u32 field_datum_byte_offset)
87 acpi_status status = AE_OK;
88 union acpi_operand_object *rgn_desc;
89 u8 space_id;
91 ACPI_FUNCTION_TRACE_U32(ex_setup_region, field_datum_byte_offset);
93 rgn_desc = obj_desc->common_field.region_obj;
95 /* We must have a valid region */
97 if (rgn_desc->common.type != ACPI_TYPE_REGION) {
98 ACPI_ERROR((AE_INFO, "Needed Region, found type 0x%X (%s)",
99 rgn_desc->common.type,
100 acpi_ut_get_object_type_name(rgn_desc)));
102 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
105 space_id = rgn_desc->region.space_id;
107 /* Validate the Space ID */
109 if (!acpi_is_valid_space_id(space_id)) {
110 ACPI_ERROR((AE_INFO,
111 "Invalid/unknown Address Space ID: 0x%2.2X",
112 space_id));
113 return_ACPI_STATUS(AE_AML_INVALID_SPACE_ID);
117 * If the Region Address and Length have not been previously evaluated,
118 * evaluate them now and save the results.
120 if (!(rgn_desc->common.flags & AOPOBJ_DATA_VALID)) {
121 status = acpi_ds_get_region_arguments(rgn_desc);
122 if (ACPI_FAILURE(status)) {
123 return_ACPI_STATUS(status);
127 /* Exit if Address/Length have been disallowed by the host OS */
129 if (rgn_desc->common.flags & AOPOBJ_INVALID) {
130 return_ACPI_STATUS(AE_AML_ILLEGAL_ADDRESS);
134 * Exit now for SMBus, GSBus or IPMI address space, it has a non-linear
135 * address space and the request cannot be directly validated
137 if (space_id == ACPI_ADR_SPACE_SMBUS ||
138 space_id == ACPI_ADR_SPACE_GSBUS ||
139 space_id == ACPI_ADR_SPACE_IPMI) {
141 /* SMBus or IPMI has a non-linear address space */
143 return_ACPI_STATUS(AE_OK);
145 #ifdef ACPI_UNDER_DEVELOPMENT
147 * If the Field access is any_acc, we can now compute the optimal
148 * access (because we know know the length of the parent region)
150 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
151 if (ACPI_FAILURE(status)) {
152 return_ACPI_STATUS(status);
155 #endif
158 * Validate the request. The entire request from the byte offset for a
159 * length of one field datum (access width) must fit within the region.
160 * (Region length is specified in bytes)
162 if (rgn_desc->region.length <
163 (obj_desc->common_field.base_byte_offset + field_datum_byte_offset +
164 obj_desc->common_field.access_byte_width)) {
165 if (acpi_gbl_enable_interpreter_slack) {
167 * Slack mode only: We will go ahead and allow access to this
168 * field if it is within the region length rounded up to the next
169 * access width boundary. acpi_size cast for 64-bit compile.
171 if (ACPI_ROUND_UP(rgn_desc->region.length,
172 obj_desc->common_field.
173 access_byte_width) >=
174 ((acpi_size) obj_desc->common_field.
175 base_byte_offset +
176 obj_desc->common_field.access_byte_width +
177 field_datum_byte_offset)) {
178 return_ACPI_STATUS(AE_OK);
182 if (rgn_desc->region.length <
183 obj_desc->common_field.access_byte_width) {
185 * This is the case where the access_type (acc_word, etc.) is wider
186 * than the region itself. For example, a region of length one
187 * byte, and a field with Dword access specified.
189 ACPI_ERROR((AE_INFO,
190 "Field [%4.4s] access width (%u bytes) too large for region [%4.4s] (length %u)",
191 acpi_ut_get_node_name(obj_desc->
192 common_field.node),
193 obj_desc->common_field.access_byte_width,
194 acpi_ut_get_node_name(rgn_desc->region.
195 node),
196 rgn_desc->region.length));
200 * Offset rounded up to next multiple of field width
201 * exceeds region length, indicate an error
203 ACPI_ERROR((AE_INFO,
204 "Field [%4.4s] Base+Offset+Width %u+%u+%u is beyond end of region [%4.4s] (length %u)",
205 acpi_ut_get_node_name(obj_desc->common_field.node),
206 obj_desc->common_field.base_byte_offset,
207 field_datum_byte_offset,
208 obj_desc->common_field.access_byte_width,
209 acpi_ut_get_node_name(rgn_desc->region.node),
210 rgn_desc->region.length));
212 return_ACPI_STATUS(AE_AML_REGION_LIMIT);
215 return_ACPI_STATUS(AE_OK);
218 /*******************************************************************************
220 * FUNCTION: acpi_ex_access_region
222 * PARAMETERS: obj_desc - Field to be read
223 * field_datum_byte_offset - Byte offset of this datum within the
224 * parent field
225 * Value - Where to store value (must at least
226 * 64 bits)
227 * Function - Read or Write flag plus other region-
228 * dependent flags
230 * RETURN: Status
232 * DESCRIPTION: Read or Write a single field datum to an Operation Region.
234 ******************************************************************************/
236 acpi_status
237 acpi_ex_access_region(union acpi_operand_object *obj_desc,
238 u32 field_datum_byte_offset, u64 *value, u32 function)
240 acpi_status status;
241 union acpi_operand_object *rgn_desc;
242 u32 region_offset;
244 ACPI_FUNCTION_TRACE(ex_access_region);
247 * Ensure that the region operands are fully evaluated and verify
248 * the validity of the request
250 status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset);
251 if (ACPI_FAILURE(status)) {
252 return_ACPI_STATUS(status);
256 * The physical address of this field datum is:
258 * 1) The base of the region, plus
259 * 2) The base offset of the field, plus
260 * 3) The current offset into the field
262 rgn_desc = obj_desc->common_field.region_obj;
263 region_offset =
264 obj_desc->common_field.base_byte_offset + field_datum_byte_offset;
266 if ((function & ACPI_IO_MASK) == ACPI_READ) {
267 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
268 } else {
269 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
272 ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
273 " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n",
274 acpi_ut_get_region_name(rgn_desc->region.
275 space_id),
276 rgn_desc->region.space_id,
277 obj_desc->common_field.access_byte_width,
278 obj_desc->common_field.base_byte_offset,
279 field_datum_byte_offset, ACPI_CAST_PTR(void,
280 (rgn_desc->
281 region.
282 address +
283 region_offset))));
285 /* Invoke the appropriate address_space/op_region handler */
287 status = acpi_ev_address_space_dispatch(rgn_desc, obj_desc,
288 function, region_offset,
289 ACPI_MUL_8(obj_desc->
290 common_field.
291 access_byte_width),
292 value);
294 if (ACPI_FAILURE(status)) {
295 if (status == AE_NOT_IMPLEMENTED) {
296 ACPI_ERROR((AE_INFO,
297 "Region %s (ID=%u) not implemented",
298 acpi_ut_get_region_name(rgn_desc->region.
299 space_id),
300 rgn_desc->region.space_id));
301 } else if (status == AE_NOT_EXIST) {
302 ACPI_ERROR((AE_INFO,
303 "Region %s (ID=%u) has no handler",
304 acpi_ut_get_region_name(rgn_desc->region.
305 space_id),
306 rgn_desc->region.space_id));
310 return_ACPI_STATUS(status);
313 /*******************************************************************************
315 * FUNCTION: acpi_ex_register_overflow
317 * PARAMETERS: obj_desc - Register(Field) to be written
318 * Value - Value to be stored
320 * RETURN: TRUE if value overflows the field, FALSE otherwise
322 * DESCRIPTION: Check if a value is out of range of the field being written.
323 * Used to check if the values written to Index and Bank registers
324 * are out of range. Normally, the value is simply truncated
325 * to fit the field, but this case is most likely a serious
326 * coding error in the ASL.
328 ******************************************************************************/
330 static u8
331 acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 value)
333 ACPI_FUNCTION_NAME(ex_register_overflow);
335 if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
337 * The field is large enough to hold the maximum integer, so we can
338 * never overflow it.
340 return (FALSE);
343 if (value >= ((u64) 1 << obj_desc->common_field.bit_length)) {
345 * The Value is larger than the maximum value that can fit into
346 * the register.
348 ACPI_ERROR((AE_INFO,
349 "Index value 0x%8.8X%8.8X overflows field width 0x%X",
350 ACPI_FORMAT_UINT64(value),
351 obj_desc->common_field.bit_length));
353 return (TRUE);
356 /* The Value will fit into the field with no truncation */
358 return (FALSE);
361 /*******************************************************************************
363 * FUNCTION: acpi_ex_field_datum_io
365 * PARAMETERS: obj_desc - Field to be read
366 * field_datum_byte_offset - Byte offset of this datum within the
367 * parent field
368 * Value - Where to store value (must be 64 bits)
369 * read_write - Read or Write flag
371 * RETURN: Status
373 * DESCRIPTION: Read or Write a single datum of a field. The field_type is
374 * demultiplexed here to handle the different types of fields
375 * (buffer_field, region_field, index_field, bank_field)
377 ******************************************************************************/
379 static acpi_status
380 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
381 u32 field_datum_byte_offset, u64 *value, u32 read_write)
383 acpi_status status;
384 u64 local_value;
386 ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
388 if (read_write == ACPI_READ) {
389 if (!value) {
390 local_value = 0;
392 /* To support reads without saving return value */
393 value = &local_value;
396 /* Clear the entire return buffer first, [Very Important!] */
398 *value = 0;
402 * The four types of fields are:
404 * buffer_field - Read/write from/to a Buffer
405 * region_field - Read/write from/to a Operation Region.
406 * bank_field - Write to a Bank Register, then read/write from/to an
407 * operation_region
408 * index_field - Write to an Index Register, then read/write from/to a
409 * Data Register
411 switch (obj_desc->common.type) {
412 case ACPI_TYPE_BUFFER_FIELD:
414 * If the buffer_field arguments have not been previously evaluated,
415 * evaluate them now and save the results.
417 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
418 status = acpi_ds_get_buffer_field_arguments(obj_desc);
419 if (ACPI_FAILURE(status)) {
420 return_ACPI_STATUS(status);
424 if (read_write == ACPI_READ) {
426 * Copy the data from the source buffer.
427 * Length is the field width in bytes.
429 ACPI_MEMCPY(value,
430 (obj_desc->buffer_field.buffer_obj)->buffer.
431 pointer +
432 obj_desc->buffer_field.base_byte_offset +
433 field_datum_byte_offset,
434 obj_desc->common_field.access_byte_width);
435 } else {
437 * Copy the data to the target buffer.
438 * Length is the field width in bytes.
440 ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer.
441 pointer +
442 obj_desc->buffer_field.base_byte_offset +
443 field_datum_byte_offset, value,
444 obj_desc->common_field.access_byte_width);
447 status = AE_OK;
448 break;
450 case ACPI_TYPE_LOCAL_BANK_FIELD:
453 * Ensure that the bank_value is not beyond the capacity of
454 * the register
456 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
457 (u64) obj_desc->bank_field.
458 value)) {
459 return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
463 * For bank_fields, we must write the bank_value to the bank_register
464 * (itself a region_field) before we can access the data.
466 status =
467 acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
468 &obj_desc->bank_field.value,
469 sizeof(obj_desc->bank_field.
470 value));
471 if (ACPI_FAILURE(status)) {
472 return_ACPI_STATUS(status);
476 * Now that the Bank has been selected, fall through to the
477 * region_field case and write the datum to the Operation Region
480 /*lint -fallthrough */
482 case ACPI_TYPE_LOCAL_REGION_FIELD:
484 * For simple region_fields, we just directly access the owning
485 * Operation Region.
487 status =
488 acpi_ex_access_region(obj_desc, field_datum_byte_offset,
489 value, read_write);
490 break;
492 case ACPI_TYPE_LOCAL_INDEX_FIELD:
495 * Ensure that the index_value is not beyond the capacity of
496 * the register
498 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
499 (u64) obj_desc->index_field.
500 value)) {
501 return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
504 /* Write the index value to the index_register (itself a region_field) */
506 field_datum_byte_offset += obj_desc->index_field.value;
508 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
509 "Write to Index Register: Value %8.8X\n",
510 field_datum_byte_offset));
512 status =
513 acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
514 &field_datum_byte_offset,
515 sizeof(field_datum_byte_offset));
516 if (ACPI_FAILURE(status)) {
517 return_ACPI_STATUS(status);
520 if (read_write == ACPI_READ) {
522 /* Read the datum from the data_register */
524 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
525 "Read from Data Register\n"));
527 status =
528 acpi_ex_extract_from_field(obj_desc->index_field.
529 data_obj, value,
530 sizeof(u64));
531 } else {
532 /* Write the datum to the data_register */
534 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
535 "Write to Data Register: Value %8.8X%8.8X\n",
536 ACPI_FORMAT_UINT64(*value)));
538 status =
539 acpi_ex_insert_into_field(obj_desc->index_field.
540 data_obj, value,
541 sizeof(u64));
543 break;
545 default:
547 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %u",
548 obj_desc->common.type));
549 status = AE_AML_INTERNAL;
550 break;
553 if (ACPI_SUCCESS(status)) {
554 if (read_write == ACPI_READ) {
555 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
556 "Value Read %8.8X%8.8X, Width %u\n",
557 ACPI_FORMAT_UINT64(*value),
558 obj_desc->common_field.
559 access_byte_width));
560 } else {
561 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
562 "Value Written %8.8X%8.8X, Width %u\n",
563 ACPI_FORMAT_UINT64(*value),
564 obj_desc->common_field.
565 access_byte_width));
569 return_ACPI_STATUS(status);
572 /*******************************************************************************
574 * FUNCTION: acpi_ex_write_with_update_rule
576 * PARAMETERS: obj_desc - Field to be written
577 * Mask - bitmask within field datum
578 * field_value - Value to write
579 * field_datum_byte_offset - Offset of datum within field
581 * RETURN: Status
583 * DESCRIPTION: Apply the field update rule to a field write
585 ******************************************************************************/
587 acpi_status
588 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc,
589 u64 mask,
590 u64 field_value, u32 field_datum_byte_offset)
592 acpi_status status = AE_OK;
593 u64 merged_value;
594 u64 current_value;
596 ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask);
598 /* Start with the new bits */
600 merged_value = field_value;
602 /* If the mask is all ones, we don't need to worry about the update rule */
604 if (mask != ACPI_UINT64_MAX) {
606 /* Decode the update rule */
608 switch (obj_desc->common_field.
609 field_flags & AML_FIELD_UPDATE_RULE_MASK) {
610 case AML_FIELD_UPDATE_PRESERVE:
612 * Check if update rule needs to be applied (not if mask is all
613 * ones) The left shift drops the bits we want to ignore.
615 if ((~mask << (ACPI_MUL_8(sizeof(mask)) -
616 ACPI_MUL_8(obj_desc->common_field.
617 access_byte_width))) != 0) {
619 * Read the current contents of the byte/word/dword containing
620 * the field, and merge with the new field value.
622 status =
623 acpi_ex_field_datum_io(obj_desc,
624 field_datum_byte_offset,
625 &current_value,
626 ACPI_READ);
627 if (ACPI_FAILURE(status)) {
628 return_ACPI_STATUS(status);
631 merged_value |= (current_value & ~mask);
633 break;
635 case AML_FIELD_UPDATE_WRITE_AS_ONES:
637 /* Set positions outside the field to all ones */
639 merged_value |= ~mask;
640 break;
642 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
644 /* Set positions outside the field to all zeros */
646 merged_value &= mask;
647 break;
649 default:
651 ACPI_ERROR((AE_INFO,
652 "Unknown UpdateRule value: 0x%X",
653 (obj_desc->common_field.
654 field_flags &
655 AML_FIELD_UPDATE_RULE_MASK)));
656 return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
660 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
661 "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
662 ACPI_FORMAT_UINT64(mask),
663 field_datum_byte_offset,
664 obj_desc->common_field.access_byte_width,
665 ACPI_FORMAT_UINT64(field_value),
666 ACPI_FORMAT_UINT64(merged_value)));
668 /* Write the merged value */
670 status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset,
671 &merged_value, ACPI_WRITE);
673 return_ACPI_STATUS(status);
676 /*******************************************************************************
678 * FUNCTION: acpi_ex_extract_from_field
680 * PARAMETERS: obj_desc - Field to be read
681 * Buffer - Where to store the field data
682 * buffer_length - Length of Buffer
684 * RETURN: Status
686 * DESCRIPTION: Retrieve the current value of the given field
688 ******************************************************************************/
690 acpi_status
691 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
692 void *buffer, u32 buffer_length)
694 acpi_status status;
695 u64 raw_datum;
696 u64 merged_datum;
697 u32 field_offset = 0;
698 u32 buffer_offset = 0;
699 u32 buffer_tail_bits;
700 u32 datum_count;
701 u32 field_datum_count;
702 u32 access_bit_width;
703 u32 i;
705 ACPI_FUNCTION_TRACE(ex_extract_from_field);
707 /* Validate target buffer and clear it */
709 if (buffer_length <
710 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
711 ACPI_ERROR((AE_INFO,
712 "Field size %u (bits) is too large for buffer (%u)",
713 obj_desc->common_field.bit_length, buffer_length));
715 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
718 ACPI_MEMSET(buffer, 0, buffer_length);
719 access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
721 /* Handle the simple case here */
723 if ((obj_desc->common_field.start_field_bit_offset == 0) &&
724 (obj_desc->common_field.bit_length == access_bit_width)) {
725 status = acpi_ex_field_datum_io(obj_desc, 0, buffer, ACPI_READ);
726 return_ACPI_STATUS(status);
729 /* TBD: Move to common setup code */
731 /* Field algorithm is limited to sizeof(u64), truncate if needed */
733 if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
734 obj_desc->common_field.access_byte_width = sizeof(u64);
735 access_bit_width = sizeof(u64) * 8;
738 /* Compute the number of datums (access width data items) */
740 datum_count =
741 ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
742 access_bit_width);
744 field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
745 obj_desc->common_field.
746 start_field_bit_offset,
747 access_bit_width);
749 /* Priming read from the field */
751 status =
752 acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
753 ACPI_READ);
754 if (ACPI_FAILURE(status)) {
755 return_ACPI_STATUS(status);
757 merged_datum =
758 raw_datum >> obj_desc->common_field.start_field_bit_offset;
760 /* Read the rest of the field */
762 for (i = 1; i < field_datum_count; i++) {
764 /* Get next input datum from the field */
766 field_offset += obj_desc->common_field.access_byte_width;
767 status = acpi_ex_field_datum_io(obj_desc, field_offset,
768 &raw_datum, ACPI_READ);
769 if (ACPI_FAILURE(status)) {
770 return_ACPI_STATUS(status);
774 * Merge with previous datum if necessary.
776 * Note: Before the shift, check if the shift value will be larger than
777 * the integer size. If so, there is no need to perform the operation.
778 * This avoids the differences in behavior between different compilers
779 * concerning shift values larger than the target data width.
781 if (access_bit_width -
782 obj_desc->common_field.start_field_bit_offset <
783 ACPI_INTEGER_BIT_SIZE) {
784 merged_datum |=
785 raw_datum << (access_bit_width -
786 obj_desc->common_field.
787 start_field_bit_offset);
790 if (i == datum_count) {
791 break;
794 /* Write merged datum to target buffer */
796 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
797 ACPI_MIN(obj_desc->common_field.access_byte_width,
798 buffer_length - buffer_offset));
800 buffer_offset += obj_desc->common_field.access_byte_width;
801 merged_datum =
802 raw_datum >> obj_desc->common_field.start_field_bit_offset;
805 /* Mask off any extra bits in the last datum */
807 buffer_tail_bits = obj_desc->common_field.bit_length % access_bit_width;
808 if (buffer_tail_bits) {
809 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
812 /* Write the last datum to the buffer */
814 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
815 ACPI_MIN(obj_desc->common_field.access_byte_width,
816 buffer_length - buffer_offset));
818 return_ACPI_STATUS(AE_OK);
821 /*******************************************************************************
823 * FUNCTION: acpi_ex_insert_into_field
825 * PARAMETERS: obj_desc - Field to be written
826 * Buffer - Data to be written
827 * buffer_length - Length of Buffer
829 * RETURN: Status
831 * DESCRIPTION: Store the Buffer contents into the given field
833 ******************************************************************************/
835 acpi_status
836 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
837 void *buffer, u32 buffer_length)
839 void *new_buffer;
840 acpi_status status;
841 u64 mask;
842 u64 width_mask;
843 u64 merged_datum;
844 u64 raw_datum = 0;
845 u32 field_offset = 0;
846 u32 buffer_offset = 0;
847 u32 buffer_tail_bits;
848 u32 datum_count;
849 u32 field_datum_count;
850 u32 access_bit_width;
851 u32 required_length;
852 u32 i;
854 ACPI_FUNCTION_TRACE(ex_insert_into_field);
856 /* Validate input buffer */
858 new_buffer = NULL;
859 required_length =
860 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
862 * We must have a buffer that is at least as long as the field
863 * we are writing to. This is because individual fields are
864 * indivisible and partial writes are not supported -- as per
865 * the ACPI specification.
867 if (buffer_length < required_length) {
869 /* We need to create a new buffer */
871 new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
872 if (!new_buffer) {
873 return_ACPI_STATUS(AE_NO_MEMORY);
877 * Copy the original data to the new buffer, starting
878 * at Byte zero. All unused (upper) bytes of the
879 * buffer will be 0.
881 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length);
882 buffer = new_buffer;
883 buffer_length = required_length;
886 /* TBD: Move to common setup code */
888 /* Algo is limited to sizeof(u64), so cut the access_byte_width */
889 if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
890 obj_desc->common_field.access_byte_width = sizeof(u64);
893 access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
896 * Create the bitmasks used for bit insertion.
897 * Note: This if/else is used to bypass compiler differences with the
898 * shift operator
900 if (access_bit_width == ACPI_INTEGER_BIT_SIZE) {
901 width_mask = ACPI_UINT64_MAX;
902 } else {
903 width_mask = ACPI_MASK_BITS_ABOVE(access_bit_width);
906 mask = width_mask &
907 ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
909 /* Compute the number of datums (access width data items) */
911 datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
912 access_bit_width);
914 field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
915 obj_desc->common_field.
916 start_field_bit_offset,
917 access_bit_width);
919 /* Get initial Datum from the input buffer */
921 ACPI_MEMCPY(&raw_datum, buffer,
922 ACPI_MIN(obj_desc->common_field.access_byte_width,
923 buffer_length - buffer_offset));
925 merged_datum =
926 raw_datum << obj_desc->common_field.start_field_bit_offset;
928 /* Write the entire field */
930 for (i = 1; i < field_datum_count; i++) {
932 /* Write merged datum to the target field */
934 merged_datum &= mask;
935 status = acpi_ex_write_with_update_rule(obj_desc, mask,
936 merged_datum,
937 field_offset);
938 if (ACPI_FAILURE(status)) {
939 goto exit;
942 field_offset += obj_desc->common_field.access_byte_width;
945 * Start new output datum by merging with previous input datum
946 * if necessary.
948 * Note: Before the shift, check if the shift value will be larger than
949 * the integer size. If so, there is no need to perform the operation.
950 * This avoids the differences in behavior between different compilers
951 * concerning shift values larger than the target data width.
953 if ((access_bit_width -
954 obj_desc->common_field.start_field_bit_offset) <
955 ACPI_INTEGER_BIT_SIZE) {
956 merged_datum =
957 raw_datum >> (access_bit_width -
958 obj_desc->common_field.
959 start_field_bit_offset);
960 } else {
961 merged_datum = 0;
964 mask = width_mask;
966 if (i == datum_count) {
967 break;
970 /* Get the next input datum from the buffer */
972 buffer_offset += obj_desc->common_field.access_byte_width;
973 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset,
974 ACPI_MIN(obj_desc->common_field.access_byte_width,
975 buffer_length - buffer_offset));
977 merged_datum |=
978 raw_datum << obj_desc->common_field.start_field_bit_offset;
981 /* Mask off any extra bits in the last datum */
983 buffer_tail_bits = (obj_desc->common_field.bit_length +
984 obj_desc->common_field.start_field_bit_offset) %
985 access_bit_width;
986 if (buffer_tail_bits) {
987 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
990 /* Write the last datum to the field */
992 merged_datum &= mask;
993 status = acpi_ex_write_with_update_rule(obj_desc,
994 mask, merged_datum,
995 field_offset);
997 exit:
998 /* Free temporary buffer if we used one */
1000 if (new_buffer) {
1001 ACPI_FREE(new_buffer);
1003 return_ACPI_STATUS(status);