1 /******************************************************************************
3 * Module Name: exfldio - Aml Field I/O
5 *****************************************************************************/
8 * Copyright (C) 2000 - 2013, Intel Corp.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
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.
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
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41 * POSSIBILITY OF SUCH DAMAGES.
44 #include <acpi/acpi.h>
51 #define _COMPONENT ACPI_EXECUTER
52 ACPI_MODULE_NAME("exfldio")
54 /* Local prototypes */
56 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
57 u32 field_datum_byte_offset, u64 *value, u32 read_write);
60 acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 value);
63 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
64 u32 field_datum_byte_offset);
66 /*******************************************************************************
68 * FUNCTION: acpi_ex_setup_region
70 * PARAMETERS: obj_desc - Field to be read or written
71 * field_datum_byte_offset - Byte offset of this datum within the
76 * DESCRIPTION: Common processing for acpi_ex_extract_from_field and
77 * acpi_ex_insert_into_field. Initialize the Region if necessary and
78 * validate the request.
80 ******************************************************************************/
83 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
84 u32 field_datum_byte_offset)
86 acpi_status status = AE_OK;
87 union acpi_operand_object *rgn_desc;
90 ACPI_FUNCTION_TRACE_U32(ex_setup_region, field_datum_byte_offset);
92 rgn_desc = obj_desc->common_field.region_obj;
94 /* We must have a valid region */
96 if (rgn_desc->common.type != ACPI_TYPE_REGION) {
97 ACPI_ERROR((AE_INFO, "Needed Region, found type 0x%X (%s)",
98 rgn_desc->common.type,
99 acpi_ut_get_object_type_name(rgn_desc)));
101 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
104 space_id = rgn_desc->region.space_id;
106 /* Validate the Space ID */
108 if (!acpi_is_valid_space_id(space_id)) {
110 "Invalid/unknown Address Space ID: 0x%2.2X",
112 return_ACPI_STATUS(AE_AML_INVALID_SPACE_ID);
116 * If the Region Address and Length have not been previously evaluated,
117 * evaluate them now and save the results.
119 if (!(rgn_desc->common.flags & AOPOBJ_DATA_VALID)) {
120 status = acpi_ds_get_region_arguments(rgn_desc);
121 if (ACPI_FAILURE(status)) {
122 return_ACPI_STATUS(status);
126 /* Exit if Address/Length have been disallowed by the host OS */
128 if (rgn_desc->common.flags & AOPOBJ_INVALID) {
129 return_ACPI_STATUS(AE_AML_ILLEGAL_ADDRESS);
133 * Exit now for SMBus, GSBus or IPMI address space, it has a non-linear
134 * address space and the request cannot be directly validated
136 if (space_id == ACPI_ADR_SPACE_SMBUS ||
137 space_id == ACPI_ADR_SPACE_GSBUS ||
138 space_id == ACPI_ADR_SPACE_IPMI) {
140 /* SMBus or IPMI has a non-linear address space */
142 return_ACPI_STATUS(AE_OK);
144 #ifdef ACPI_UNDER_DEVELOPMENT
146 * If the Field access is any_acc, we can now compute the optimal
147 * access (because we know know the length of the parent region)
149 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
150 if (ACPI_FAILURE(status)) {
151 return_ACPI_STATUS(status);
157 * Validate the request. The entire request from the byte offset for a
158 * length of one field datum (access width) must fit within the region.
159 * (Region length is specified in bytes)
161 if (rgn_desc->region.length <
162 (obj_desc->common_field.base_byte_offset + field_datum_byte_offset +
163 obj_desc->common_field.access_byte_width)) {
164 if (acpi_gbl_enable_interpreter_slack) {
166 * Slack mode only: We will go ahead and allow access to this
167 * field if it is within the region length rounded up to the next
168 * access width boundary. acpi_size cast for 64-bit compile.
170 if (ACPI_ROUND_UP(rgn_desc->region.length,
171 obj_desc->common_field.
172 access_byte_width) >=
173 ((acpi_size) obj_desc->common_field.
175 obj_desc->common_field.access_byte_width +
176 field_datum_byte_offset)) {
177 return_ACPI_STATUS(AE_OK);
181 if (rgn_desc->region.length <
182 obj_desc->common_field.access_byte_width) {
184 * This is the case where the access_type (acc_word, etc.) is wider
185 * than the region itself. For example, a region of length one
186 * byte, and a field with Dword access specified.
189 "Field [%4.4s] access width (%u bytes) too large for region [%4.4s] (length %u)",
190 acpi_ut_get_node_name(obj_desc->
192 obj_desc->common_field.access_byte_width,
193 acpi_ut_get_node_name(rgn_desc->region.
195 rgn_desc->region.length));
199 * Offset rounded up to next multiple of field width
200 * exceeds region length, indicate an error
203 "Field [%4.4s] Base+Offset+Width %u+%u+%u is beyond end of region [%4.4s] (length %u)",
204 acpi_ut_get_node_name(obj_desc->common_field.node),
205 obj_desc->common_field.base_byte_offset,
206 field_datum_byte_offset,
207 obj_desc->common_field.access_byte_width,
208 acpi_ut_get_node_name(rgn_desc->region.node),
209 rgn_desc->region.length));
211 return_ACPI_STATUS(AE_AML_REGION_LIMIT);
214 return_ACPI_STATUS(AE_OK);
217 /*******************************************************************************
219 * FUNCTION: acpi_ex_access_region
221 * PARAMETERS: obj_desc - Field to be read
222 * field_datum_byte_offset - Byte offset of this datum within the
224 * value - Where to store value (must at least
226 * function - Read or Write flag plus other region-
231 * DESCRIPTION: Read or Write a single field datum to an Operation Region.
233 ******************************************************************************/
236 acpi_ex_access_region(union acpi_operand_object *obj_desc,
237 u32 field_datum_byte_offset, u64 *value, u32 function)
240 union acpi_operand_object *rgn_desc;
243 ACPI_FUNCTION_TRACE(ex_access_region);
246 * Ensure that the region operands are fully evaluated and verify
247 * the validity of the request
249 status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset);
250 if (ACPI_FAILURE(status)) {
251 return_ACPI_STATUS(status);
255 * The physical address of this field datum is:
257 * 1) The base of the region, plus
258 * 2) The base offset of the field, plus
259 * 3) The current offset into the field
261 rgn_desc = obj_desc->common_field.region_obj;
263 obj_desc->common_field.base_byte_offset + field_datum_byte_offset;
265 if ((function & ACPI_IO_MASK) == ACPI_READ) {
266 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
268 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
271 ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
272 " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n",
273 acpi_ut_get_region_name(rgn_desc->region.
275 rgn_desc->region.space_id,
276 obj_desc->common_field.access_byte_width,
277 obj_desc->common_field.base_byte_offset,
278 field_datum_byte_offset, ACPI_CAST_PTR(void,
284 /* Invoke the appropriate address_space/op_region handler */
286 status = acpi_ev_address_space_dispatch(rgn_desc, obj_desc,
287 function, region_offset,
288 ACPI_MUL_8(obj_desc->
293 if (ACPI_FAILURE(status)) {
294 if (status == AE_NOT_IMPLEMENTED) {
296 "Region %s (ID=%u) not implemented",
297 acpi_ut_get_region_name(rgn_desc->region.
299 rgn_desc->region.space_id));
300 } else if (status == AE_NOT_EXIST) {
302 "Region %s (ID=%u) has no handler",
303 acpi_ut_get_region_name(rgn_desc->region.
305 rgn_desc->region.space_id));
309 return_ACPI_STATUS(status);
312 /*******************************************************************************
314 * FUNCTION: acpi_ex_register_overflow
316 * PARAMETERS: obj_desc - Register(Field) to be written
317 * value - Value to be stored
319 * RETURN: TRUE if value overflows the field, FALSE otherwise
321 * DESCRIPTION: Check if a value is out of range of the field being written.
322 * Used to check if the values written to Index and Bank registers
323 * are out of range. Normally, the value is simply truncated
324 * to fit the field, but this case is most likely a serious
325 * coding error in the ASL.
327 ******************************************************************************/
330 acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 value)
333 if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
335 * The field is large enough to hold the maximum integer, so we can
341 if (value >= ((u64) 1 << obj_desc->common_field.bit_length)) {
343 * The Value is larger than the maximum value that can fit into
347 "Index value 0x%8.8X%8.8X overflows field width 0x%X",
348 ACPI_FORMAT_UINT64(value),
349 obj_desc->common_field.bit_length));
354 /* The Value will fit into the field with no truncation */
359 /*******************************************************************************
361 * FUNCTION: acpi_ex_field_datum_io
363 * PARAMETERS: obj_desc - Field to be read
364 * field_datum_byte_offset - Byte offset of this datum within the
366 * value - Where to store value (must be 64 bits)
367 * read_write - Read or Write flag
371 * DESCRIPTION: Read or Write a single datum of a field. The field_type is
372 * demultiplexed here to handle the different types of fields
373 * (buffer_field, region_field, index_field, bank_field)
375 ******************************************************************************/
378 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
379 u32 field_datum_byte_offset, u64 *value, u32 read_write)
384 ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
386 if (read_write == ACPI_READ) {
390 /* To support reads without saving return value */
391 value = &local_value;
394 /* Clear the entire return buffer first, [Very Important!] */
400 * The four types of fields are:
402 * buffer_field - Read/write from/to a Buffer
403 * region_field - Read/write from/to a Operation Region.
404 * bank_field - Write to a Bank Register, then read/write from/to an
406 * index_field - Write to an Index Register, then read/write from/to a
409 switch (obj_desc->common.type) {
410 case ACPI_TYPE_BUFFER_FIELD:
412 * If the buffer_field arguments have not been previously evaluated,
413 * evaluate them now and save the results.
415 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
416 status = acpi_ds_get_buffer_field_arguments(obj_desc);
417 if (ACPI_FAILURE(status)) {
418 return_ACPI_STATUS(status);
422 if (read_write == ACPI_READ) {
424 * Copy the data from the source buffer.
425 * Length is the field width in bytes.
428 (obj_desc->buffer_field.buffer_obj)->buffer.
430 obj_desc->buffer_field.base_byte_offset +
431 field_datum_byte_offset,
432 obj_desc->common_field.access_byte_width);
435 * Copy the data to the target buffer.
436 * Length is the field width in bytes.
438 ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer.
440 obj_desc->buffer_field.base_byte_offset +
441 field_datum_byte_offset, value,
442 obj_desc->common_field.access_byte_width);
448 case ACPI_TYPE_LOCAL_BANK_FIELD:
451 * Ensure that the bank_value is not beyond the capacity of
454 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
455 (u64) obj_desc->bank_field.
457 return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
461 * For bank_fields, we must write the bank_value to the bank_register
462 * (itself a region_field) before we can access the data.
465 acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
466 &obj_desc->bank_field.value,
467 sizeof(obj_desc->bank_field.
469 if (ACPI_FAILURE(status)) {
470 return_ACPI_STATUS(status);
474 * Now that the Bank has been selected, fall through to the
475 * region_field case and write the datum to the Operation Region
478 /*lint -fallthrough */
480 case ACPI_TYPE_LOCAL_REGION_FIELD:
482 * For simple region_fields, we just directly access the owning
486 acpi_ex_access_region(obj_desc, field_datum_byte_offset,
490 case ACPI_TYPE_LOCAL_INDEX_FIELD:
493 * Ensure that the index_value is not beyond the capacity of
496 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
497 (u64) obj_desc->index_field.
499 return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
502 /* Write the index value to the index_register (itself a region_field) */
504 field_datum_byte_offset += obj_desc->index_field.value;
506 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
507 "Write to Index Register: Value %8.8X\n",
508 field_datum_byte_offset));
511 acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
512 &field_datum_byte_offset,
513 sizeof(field_datum_byte_offset));
514 if (ACPI_FAILURE(status)) {
515 return_ACPI_STATUS(status);
518 if (read_write == ACPI_READ) {
520 /* Read the datum from the data_register */
522 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
523 "Read from Data Register\n"));
526 acpi_ex_extract_from_field(obj_desc->index_field.
530 /* Write the datum to the data_register */
532 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
533 "Write to Data Register: Value %8.8X%8.8X\n",
534 ACPI_FORMAT_UINT64(*value)));
537 acpi_ex_insert_into_field(obj_desc->index_field.
545 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %u",
546 obj_desc->common.type));
547 status = AE_AML_INTERNAL;
551 if (ACPI_SUCCESS(status)) {
552 if (read_write == ACPI_READ) {
553 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
554 "Value Read %8.8X%8.8X, Width %u\n",
555 ACPI_FORMAT_UINT64(*value),
556 obj_desc->common_field.
559 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
560 "Value Written %8.8X%8.8X, Width %u\n",
561 ACPI_FORMAT_UINT64(*value),
562 obj_desc->common_field.
567 return_ACPI_STATUS(status);
570 /*******************************************************************************
572 * FUNCTION: acpi_ex_write_with_update_rule
574 * PARAMETERS: obj_desc - Field to be written
575 * mask - bitmask within field datum
576 * field_value - Value to write
577 * field_datum_byte_offset - Offset of datum within field
581 * DESCRIPTION: Apply the field update rule to a field write
583 ******************************************************************************/
586 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc,
588 u64 field_value, u32 field_datum_byte_offset)
590 acpi_status status = AE_OK;
594 ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask);
596 /* Start with the new bits */
598 merged_value = field_value;
600 /* If the mask is all ones, we don't need to worry about the update rule */
602 if (mask != ACPI_UINT64_MAX) {
604 /* Decode the update rule */
606 switch (obj_desc->common_field.
607 field_flags & AML_FIELD_UPDATE_RULE_MASK) {
608 case AML_FIELD_UPDATE_PRESERVE:
610 * Check if update rule needs to be applied (not if mask is all
611 * ones) The left shift drops the bits we want to ignore.
613 if ((~mask << (ACPI_MUL_8(sizeof(mask)) -
614 ACPI_MUL_8(obj_desc->common_field.
615 access_byte_width))) != 0) {
617 * Read the current contents of the byte/word/dword containing
618 * the field, and merge with the new field value.
621 acpi_ex_field_datum_io(obj_desc,
622 field_datum_byte_offset,
625 if (ACPI_FAILURE(status)) {
626 return_ACPI_STATUS(status);
629 merged_value |= (current_value & ~mask);
633 case AML_FIELD_UPDATE_WRITE_AS_ONES:
635 /* Set positions outside the field to all ones */
637 merged_value |= ~mask;
640 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
642 /* Set positions outside the field to all zeros */
644 merged_value &= mask;
650 "Unknown UpdateRule value: 0x%X",
651 (obj_desc->common_field.
653 AML_FIELD_UPDATE_RULE_MASK)));
654 return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
658 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
659 "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
660 ACPI_FORMAT_UINT64(mask),
661 field_datum_byte_offset,
662 obj_desc->common_field.access_byte_width,
663 ACPI_FORMAT_UINT64(field_value),
664 ACPI_FORMAT_UINT64(merged_value)));
666 /* Write the merged value */
668 status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset,
669 &merged_value, ACPI_WRITE);
671 return_ACPI_STATUS(status);
674 /*******************************************************************************
676 * FUNCTION: acpi_ex_extract_from_field
678 * PARAMETERS: obj_desc - Field to be read
679 * buffer - Where to store the field data
680 * buffer_length - Length of Buffer
684 * DESCRIPTION: Retrieve the current value of the given field
686 ******************************************************************************/
689 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
690 void *buffer, u32 buffer_length)
695 u32 field_offset = 0;
696 u32 buffer_offset = 0;
697 u32 buffer_tail_bits;
699 u32 field_datum_count;
700 u32 access_bit_width;
703 ACPI_FUNCTION_TRACE(ex_extract_from_field);
705 /* Validate target buffer and clear it */
708 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
710 "Field size %u (bits) is too large for buffer (%u)",
711 obj_desc->common_field.bit_length, buffer_length));
713 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
716 ACPI_MEMSET(buffer, 0, buffer_length);
717 access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
719 /* Handle the simple case here */
721 if ((obj_desc->common_field.start_field_bit_offset == 0) &&
722 (obj_desc->common_field.bit_length == access_bit_width)) {
723 status = acpi_ex_field_datum_io(obj_desc, 0, buffer, ACPI_READ);
724 return_ACPI_STATUS(status);
727 /* TBD: Move to common setup code */
729 /* Field algorithm is limited to sizeof(u64), truncate if needed */
731 if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
732 obj_desc->common_field.access_byte_width = sizeof(u64);
733 access_bit_width = sizeof(u64) * 8;
736 /* Compute the number of datums (access width data items) */
739 ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
742 field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
743 obj_desc->common_field.
744 start_field_bit_offset,
747 /* Priming read from the field */
750 acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
752 if (ACPI_FAILURE(status)) {
753 return_ACPI_STATUS(status);
756 raw_datum >> obj_desc->common_field.start_field_bit_offset;
758 /* Read the rest of the field */
760 for (i = 1; i < field_datum_count; i++) {
762 /* Get next input datum from the field */
764 field_offset += obj_desc->common_field.access_byte_width;
765 status = acpi_ex_field_datum_io(obj_desc, field_offset,
766 &raw_datum, ACPI_READ);
767 if (ACPI_FAILURE(status)) {
768 return_ACPI_STATUS(status);
772 * Merge with previous datum if necessary.
774 * Note: Before the shift, check if the shift value will be larger than
775 * the integer size. If so, there is no need to perform the operation.
776 * This avoids the differences in behavior between different compilers
777 * concerning shift values larger than the target data width.
779 if (access_bit_width -
780 obj_desc->common_field.start_field_bit_offset <
781 ACPI_INTEGER_BIT_SIZE) {
783 raw_datum << (access_bit_width -
784 obj_desc->common_field.
785 start_field_bit_offset);
788 if (i == datum_count) {
792 /* Write merged datum to target buffer */
794 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
795 ACPI_MIN(obj_desc->common_field.access_byte_width,
796 buffer_length - buffer_offset));
798 buffer_offset += obj_desc->common_field.access_byte_width;
800 raw_datum >> obj_desc->common_field.start_field_bit_offset;
803 /* Mask off any extra bits in the last datum */
805 buffer_tail_bits = obj_desc->common_field.bit_length % access_bit_width;
806 if (buffer_tail_bits) {
807 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
810 /* Write the last datum to the buffer */
812 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
813 ACPI_MIN(obj_desc->common_field.access_byte_width,
814 buffer_length - buffer_offset));
816 return_ACPI_STATUS(AE_OK);
819 /*******************************************************************************
821 * FUNCTION: acpi_ex_insert_into_field
823 * PARAMETERS: obj_desc - Field to be written
824 * buffer - Data to be written
825 * buffer_length - Length of Buffer
829 * DESCRIPTION: Store the Buffer contents into the given field
831 ******************************************************************************/
834 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
835 void *buffer, u32 buffer_length)
843 u32 field_offset = 0;
844 u32 buffer_offset = 0;
845 u32 buffer_tail_bits;
847 u32 field_datum_count;
848 u32 access_bit_width;
852 ACPI_FUNCTION_TRACE(ex_insert_into_field);
854 /* Validate input buffer */
858 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
860 * We must have a buffer that is at least as long as the field
861 * we are writing to. This is because individual fields are
862 * indivisible and partial writes are not supported -- as per
863 * the ACPI specification.
865 if (buffer_length < required_length) {
867 /* We need to create a new buffer */
869 new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
871 return_ACPI_STATUS(AE_NO_MEMORY);
875 * Copy the original data to the new buffer, starting
876 * at Byte zero. All unused (upper) bytes of the
879 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length);
881 buffer_length = required_length;
884 /* TBD: Move to common setup code */
886 /* Algo is limited to sizeof(u64), so cut the access_byte_width */
887 if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
888 obj_desc->common_field.access_byte_width = sizeof(u64);
891 access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
894 * Create the bitmasks used for bit insertion.
895 * Note: This if/else is used to bypass compiler differences with the
898 if (access_bit_width == ACPI_INTEGER_BIT_SIZE) {
899 width_mask = ACPI_UINT64_MAX;
901 width_mask = ACPI_MASK_BITS_ABOVE(access_bit_width);
905 ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
907 /* Compute the number of datums (access width data items) */
909 datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
912 field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
913 obj_desc->common_field.
914 start_field_bit_offset,
917 /* Get initial Datum from the input buffer */
919 ACPI_MEMCPY(&raw_datum, buffer,
920 ACPI_MIN(obj_desc->common_field.access_byte_width,
921 buffer_length - buffer_offset));
924 raw_datum << obj_desc->common_field.start_field_bit_offset;
926 /* Write the entire field */
928 for (i = 1; i < field_datum_count; i++) {
930 /* Write merged datum to the target field */
932 merged_datum &= mask;
933 status = acpi_ex_write_with_update_rule(obj_desc, mask,
936 if (ACPI_FAILURE(status)) {
940 field_offset += obj_desc->common_field.access_byte_width;
943 * Start new output datum by merging with previous input datum
946 * Note: Before the shift, check if the shift value will be larger than
947 * the integer size. If so, there is no need to perform the operation.
948 * This avoids the differences in behavior between different compilers
949 * concerning shift values larger than the target data width.
951 if ((access_bit_width -
952 obj_desc->common_field.start_field_bit_offset) <
953 ACPI_INTEGER_BIT_SIZE) {
955 raw_datum >> (access_bit_width -
956 obj_desc->common_field.
957 start_field_bit_offset);
964 if (i == datum_count) {
968 /* Get the next input datum from the buffer */
970 buffer_offset += obj_desc->common_field.access_byte_width;
971 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset,
972 ACPI_MIN(obj_desc->common_field.access_byte_width,
973 buffer_length - buffer_offset));
976 raw_datum << obj_desc->common_field.start_field_bit_offset;
979 /* Mask off any extra bits in the last datum */
981 buffer_tail_bits = (obj_desc->common_field.bit_length +
982 obj_desc->common_field.start_field_bit_offset) %
984 if (buffer_tail_bits) {
985 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
988 /* Write the last datum to the field */
990 merged_datum &= mask;
991 status = acpi_ex_write_with_update_rule(obj_desc,
996 /* Free temporary buffer if we used one */
999 ACPI_FREE(new_buffer);
1001 return_ACPI_STATUS(status);