1 /******************************************************************************
3 * Module Name: exfldio - Aml Field I/O
5 *****************************************************************************/
8 * Copyright (C) 2000 - 2015, 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);
127 * Exit now for SMBus, GSBus or IPMI address space, it has a non-linear
128 * address space and the request cannot be directly validated
130 if (space_id == ACPI_ADR_SPACE_SMBUS ||
131 space_id == ACPI_ADR_SPACE_GSBUS ||
132 space_id == ACPI_ADR_SPACE_IPMI) {
134 /* SMBus or IPMI has a non-linear address space */
136 return_ACPI_STATUS(AE_OK);
138 #ifdef ACPI_UNDER_DEVELOPMENT
140 * If the Field access is any_acc, we can now compute the optimal
141 * access (because we know know the length of the parent region)
143 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
144 if (ACPI_FAILURE(status)) {
145 return_ACPI_STATUS(status);
151 * Validate the request. The entire request from the byte offset for a
152 * length of one field datum (access width) must fit within the region.
153 * (Region length is specified in bytes)
155 if (rgn_desc->region.length <
156 (obj_desc->common_field.base_byte_offset + field_datum_byte_offset +
157 obj_desc->common_field.access_byte_width)) {
158 if (acpi_gbl_enable_interpreter_slack) {
160 * Slack mode only: We will go ahead and allow access to this
161 * field if it is within the region length rounded up to the next
162 * access width boundary. acpi_size cast for 64-bit compile.
164 if (ACPI_ROUND_UP(rgn_desc->region.length,
165 obj_desc->common_field.
166 access_byte_width) >=
167 ((acpi_size) obj_desc->common_field.
169 obj_desc->common_field.access_byte_width +
170 field_datum_byte_offset)) {
171 return_ACPI_STATUS(AE_OK);
175 if (rgn_desc->region.length <
176 obj_desc->common_field.access_byte_width) {
178 * This is the case where the access_type (acc_word, etc.) is wider
179 * than the region itself. For example, a region of length one
180 * byte, and a field with Dword access specified.
183 "Field [%4.4s] access width (%u bytes) too large for region [%4.4s] (length %u)",
184 acpi_ut_get_node_name(obj_desc->
186 obj_desc->common_field.access_byte_width,
187 acpi_ut_get_node_name(rgn_desc->region.
189 rgn_desc->region.length));
193 * Offset rounded up to next multiple of field width
194 * exceeds region length, indicate an error
197 "Field [%4.4s] Base+Offset+Width %u+%u+%u is beyond end of region [%4.4s] (length %u)",
198 acpi_ut_get_node_name(obj_desc->common_field.node),
199 obj_desc->common_field.base_byte_offset,
200 field_datum_byte_offset,
201 obj_desc->common_field.access_byte_width,
202 acpi_ut_get_node_name(rgn_desc->region.node),
203 rgn_desc->region.length));
205 return_ACPI_STATUS(AE_AML_REGION_LIMIT);
208 return_ACPI_STATUS(AE_OK);
211 /*******************************************************************************
213 * FUNCTION: acpi_ex_access_region
215 * PARAMETERS: obj_desc - Field to be read
216 * field_datum_byte_offset - Byte offset of this datum within the
218 * value - Where to store value (must at least
220 * function - Read or Write flag plus other region-
225 * DESCRIPTION: Read or Write a single field datum to an Operation Region.
227 ******************************************************************************/
230 acpi_ex_access_region(union acpi_operand_object *obj_desc,
231 u32 field_datum_byte_offset, u64 *value, u32 function)
234 union acpi_operand_object *rgn_desc;
237 ACPI_FUNCTION_TRACE(ex_access_region);
240 * Ensure that the region operands are fully evaluated and verify
241 * the validity of the request
243 status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset);
244 if (ACPI_FAILURE(status)) {
245 return_ACPI_STATUS(status);
249 * The physical address of this field datum is:
251 * 1) The base of the region, plus
252 * 2) The base offset of the field, plus
253 * 3) The current offset into the field
255 rgn_desc = obj_desc->common_field.region_obj;
257 obj_desc->common_field.base_byte_offset + field_datum_byte_offset;
259 if ((function & ACPI_IO_MASK) == ACPI_READ) {
260 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
262 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
265 ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
266 " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n",
267 acpi_ut_get_region_name(rgn_desc->region.
269 rgn_desc->region.space_id,
270 obj_desc->common_field.access_byte_width,
271 obj_desc->common_field.base_byte_offset,
272 field_datum_byte_offset, ACPI_CAST_PTR(void,
278 /* Invoke the appropriate address_space/op_region handler */
280 status = acpi_ev_address_space_dispatch(rgn_desc, obj_desc,
281 function, region_offset,
282 ACPI_MUL_8(obj_desc->
287 if (ACPI_FAILURE(status)) {
288 if (status == AE_NOT_IMPLEMENTED) {
290 "Region %s (ID=%u) not implemented",
291 acpi_ut_get_region_name(rgn_desc->region.
293 rgn_desc->region.space_id));
294 } else if (status == AE_NOT_EXIST) {
296 "Region %s (ID=%u) has no handler",
297 acpi_ut_get_region_name(rgn_desc->region.
299 rgn_desc->region.space_id));
303 return_ACPI_STATUS(status);
306 /*******************************************************************************
308 * FUNCTION: acpi_ex_register_overflow
310 * PARAMETERS: obj_desc - Register(Field) to be written
311 * value - Value to be stored
313 * RETURN: TRUE if value overflows the field, FALSE otherwise
315 * DESCRIPTION: Check if a value is out of range of the field being written.
316 * Used to check if the values written to Index and Bank registers
317 * are out of range. Normally, the value is simply truncated
318 * to fit the field, but this case is most likely a serious
319 * coding error in the ASL.
321 ******************************************************************************/
324 acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 value)
327 if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
329 * The field is large enough to hold the maximum integer, so we can
335 if (value >= ((u64) 1 << obj_desc->common_field.bit_length)) {
337 * The Value is larger than the maximum value that can fit into
341 "Index value 0x%8.8X%8.8X overflows field width 0x%X",
342 ACPI_FORMAT_UINT64(value),
343 obj_desc->common_field.bit_length));
348 /* The Value will fit into the field with no truncation */
353 /*******************************************************************************
355 * FUNCTION: acpi_ex_field_datum_io
357 * PARAMETERS: obj_desc - Field to be read
358 * field_datum_byte_offset - Byte offset of this datum within the
360 * value - Where to store value (must be 64 bits)
361 * read_write - Read or Write flag
365 * DESCRIPTION: Read or Write a single datum of a field. The field_type is
366 * demultiplexed here to handle the different types of fields
367 * (buffer_field, region_field, index_field, bank_field)
369 ******************************************************************************/
372 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
373 u32 field_datum_byte_offset, u64 *value, u32 read_write)
378 ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
380 if (read_write == ACPI_READ) {
384 /* To support reads without saving return value */
385 value = &local_value;
388 /* Clear the entire return buffer first, [Very Important!] */
394 * The four types of fields are:
396 * buffer_field - Read/write from/to a Buffer
397 * region_field - Read/write from/to a Operation Region.
398 * bank_field - Write to a Bank Register, then read/write from/to an
400 * index_field - Write to an Index Register, then read/write from/to a
403 switch (obj_desc->common.type) {
404 case ACPI_TYPE_BUFFER_FIELD:
406 * If the buffer_field arguments have not been previously evaluated,
407 * evaluate them now and save the results.
409 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
410 status = acpi_ds_get_buffer_field_arguments(obj_desc);
411 if (ACPI_FAILURE(status)) {
412 return_ACPI_STATUS(status);
416 if (read_write == ACPI_READ) {
418 * Copy the data from the source buffer.
419 * Length is the field width in bytes.
422 (obj_desc->buffer_field.buffer_obj)->buffer.
424 obj_desc->buffer_field.base_byte_offset +
425 field_datum_byte_offset,
426 obj_desc->common_field.access_byte_width);
429 * Copy the data to the target buffer.
430 * Length is the field width in bytes.
432 ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer.
434 obj_desc->buffer_field.base_byte_offset +
435 field_datum_byte_offset, value,
436 obj_desc->common_field.access_byte_width);
442 case ACPI_TYPE_LOCAL_BANK_FIELD:
444 * Ensure that the bank_value is not beyond the capacity of
447 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
448 (u64) obj_desc->bank_field.
450 return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
454 * For bank_fields, we must write the bank_value to the bank_register
455 * (itself a region_field) before we can access the data.
458 acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
459 &obj_desc->bank_field.value,
460 sizeof(obj_desc->bank_field.
462 if (ACPI_FAILURE(status)) {
463 return_ACPI_STATUS(status);
467 * Now that the Bank has been selected, fall through to the
468 * region_field case and write the datum to the Operation Region
471 /*lint -fallthrough */
473 case ACPI_TYPE_LOCAL_REGION_FIELD:
475 * For simple region_fields, we just directly access the owning
479 acpi_ex_access_region(obj_desc, field_datum_byte_offset,
483 case ACPI_TYPE_LOCAL_INDEX_FIELD:
485 * Ensure that the index_value is not beyond the capacity of
488 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
489 (u64) obj_desc->index_field.
491 return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
494 /* Write the index value to the index_register (itself a region_field) */
496 field_datum_byte_offset += obj_desc->index_field.value;
498 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
499 "Write to Index Register: Value %8.8X\n",
500 field_datum_byte_offset));
503 acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
504 &field_datum_byte_offset,
505 sizeof(field_datum_byte_offset));
506 if (ACPI_FAILURE(status)) {
507 return_ACPI_STATUS(status);
510 if (read_write == ACPI_READ) {
512 /* Read the datum from the data_register */
514 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
515 "Read from Data Register\n"));
518 acpi_ex_extract_from_field(obj_desc->index_field.
522 /* Write the datum to the data_register */
524 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
525 "Write to Data Register: Value %8.8X%8.8X\n",
526 ACPI_FORMAT_UINT64(*value)));
529 acpi_ex_insert_into_field(obj_desc->index_field.
537 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %u",
538 obj_desc->common.type));
539 status = AE_AML_INTERNAL;
543 if (ACPI_SUCCESS(status)) {
544 if (read_write == ACPI_READ) {
545 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
546 "Value Read %8.8X%8.8X, Width %u\n",
547 ACPI_FORMAT_UINT64(*value),
548 obj_desc->common_field.
551 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
552 "Value Written %8.8X%8.8X, Width %u\n",
553 ACPI_FORMAT_UINT64(*value),
554 obj_desc->common_field.
559 return_ACPI_STATUS(status);
562 /*******************************************************************************
564 * FUNCTION: acpi_ex_write_with_update_rule
566 * PARAMETERS: obj_desc - Field to be written
567 * mask - bitmask within field datum
568 * field_value - Value to write
569 * field_datum_byte_offset - Offset of datum within field
573 * DESCRIPTION: Apply the field update rule to a field write
575 ******************************************************************************/
578 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc,
580 u64 field_value, u32 field_datum_byte_offset)
582 acpi_status status = AE_OK;
586 ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask);
588 /* Start with the new bits */
590 merged_value = field_value;
592 /* If the mask is all ones, we don't need to worry about the update rule */
594 if (mask != ACPI_UINT64_MAX) {
596 /* Decode the update rule */
598 switch (obj_desc->common_field.
599 field_flags & AML_FIELD_UPDATE_RULE_MASK) {
600 case AML_FIELD_UPDATE_PRESERVE:
602 * Check if update rule needs to be applied (not if mask is all
603 * ones) The left shift drops the bits we want to ignore.
605 if ((~mask << (ACPI_MUL_8(sizeof(mask)) -
606 ACPI_MUL_8(obj_desc->common_field.
607 access_byte_width))) != 0) {
609 * Read the current contents of the byte/word/dword containing
610 * the field, and merge with the new field value.
613 acpi_ex_field_datum_io(obj_desc,
614 field_datum_byte_offset,
617 if (ACPI_FAILURE(status)) {
618 return_ACPI_STATUS(status);
621 merged_value |= (current_value & ~mask);
625 case AML_FIELD_UPDATE_WRITE_AS_ONES:
627 /* Set positions outside the field to all ones */
629 merged_value |= ~mask;
632 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
634 /* Set positions outside the field to all zeros */
636 merged_value &= mask;
642 "Unknown UpdateRule value: 0x%X",
643 (obj_desc->common_field.
645 AML_FIELD_UPDATE_RULE_MASK)));
646 return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
650 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
651 "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
652 ACPI_FORMAT_UINT64(mask),
653 field_datum_byte_offset,
654 obj_desc->common_field.access_byte_width,
655 ACPI_FORMAT_UINT64(field_value),
656 ACPI_FORMAT_UINT64(merged_value)));
658 /* Write the merged value */
660 status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset,
661 &merged_value, ACPI_WRITE);
663 return_ACPI_STATUS(status);
666 /*******************************************************************************
668 * FUNCTION: acpi_ex_extract_from_field
670 * PARAMETERS: obj_desc - Field to be read
671 * buffer - Where to store the field data
672 * buffer_length - Length of Buffer
676 * DESCRIPTION: Retrieve the current value of the given field
678 ******************************************************************************/
681 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
682 void *buffer, u32 buffer_length)
687 u32 field_offset = 0;
688 u32 buffer_offset = 0;
689 u32 buffer_tail_bits;
691 u32 field_datum_count;
692 u32 access_bit_width;
695 ACPI_FUNCTION_TRACE(ex_extract_from_field);
697 /* Validate target buffer and clear it */
700 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
702 "Field size %u (bits) is too large for buffer (%u)",
703 obj_desc->common_field.bit_length, buffer_length));
705 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
708 ACPI_MEMSET(buffer, 0, buffer_length);
709 access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
711 /* Handle the simple case here */
713 if ((obj_desc->common_field.start_field_bit_offset == 0) &&
714 (obj_desc->common_field.bit_length == access_bit_width)) {
715 if (buffer_length >= sizeof(u64)) {
717 acpi_ex_field_datum_io(obj_desc, 0, buffer,
720 /* Use raw_datum (u64) to handle buffers < 64 bits */
723 acpi_ex_field_datum_io(obj_desc, 0, &raw_datum,
725 ACPI_MEMCPY(buffer, &raw_datum, buffer_length);
728 return_ACPI_STATUS(status);
731 /* TBD: Move to common setup code */
733 /* Field algorithm is limited to sizeof(u64), truncate if needed */
735 if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
736 obj_desc->common_field.access_byte_width = sizeof(u64);
737 access_bit_width = sizeof(u64) * 8;
740 /* Compute the number of datums (access width data items) */
743 ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
746 field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
747 obj_desc->common_field.
748 start_field_bit_offset,
751 /* Priming read from the field */
754 acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
756 if (ACPI_FAILURE(status)) {
757 return_ACPI_STATUS(status);
760 raw_datum >> obj_desc->common_field.start_field_bit_offset;
762 /* Read the rest of the field */
764 for (i = 1; i < field_datum_count; i++) {
766 /* Get next input datum from the field */
768 field_offset += obj_desc->common_field.access_byte_width;
769 status = acpi_ex_field_datum_io(obj_desc, field_offset,
770 &raw_datum, ACPI_READ);
771 if (ACPI_FAILURE(status)) {
772 return_ACPI_STATUS(status);
776 * Merge with previous datum if necessary.
778 * Note: Before the shift, check if the shift value will be larger than
779 * the integer size. If so, there is no need to perform the operation.
780 * This avoids the differences in behavior between different compilers
781 * concerning shift values larger than the target data width.
783 if (access_bit_width -
784 obj_desc->common_field.start_field_bit_offset <
785 ACPI_INTEGER_BIT_SIZE) {
787 raw_datum << (access_bit_width -
788 obj_desc->common_field.
789 start_field_bit_offset);
792 if (i == datum_count) {
796 /* Write merged datum to target buffer */
798 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
799 ACPI_MIN(obj_desc->common_field.access_byte_width,
800 buffer_length - buffer_offset));
802 buffer_offset += obj_desc->common_field.access_byte_width;
804 raw_datum >> obj_desc->common_field.start_field_bit_offset;
807 /* Mask off any extra bits in the last datum */
809 buffer_tail_bits = obj_desc->common_field.bit_length % access_bit_width;
810 if (buffer_tail_bits) {
811 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
814 /* Write the last datum to the buffer */
816 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
817 ACPI_MIN(obj_desc->common_field.access_byte_width,
818 buffer_length - buffer_offset));
820 return_ACPI_STATUS(AE_OK);
823 /*******************************************************************************
825 * FUNCTION: acpi_ex_insert_into_field
827 * PARAMETERS: obj_desc - Field to be written
828 * buffer - Data to be written
829 * buffer_length - Length of Buffer
833 * DESCRIPTION: Store the Buffer contents into the given field
835 ******************************************************************************/
838 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
839 void *buffer, u32 buffer_length)
847 u32 field_offset = 0;
848 u32 buffer_offset = 0;
849 u32 buffer_tail_bits;
851 u32 field_datum_count;
852 u32 access_bit_width;
856 ACPI_FUNCTION_TRACE(ex_insert_into_field);
858 /* Validate input buffer */
862 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
864 * We must have a buffer that is at least as long as the field
865 * we are writing to. This is because individual fields are
866 * indivisible and partial writes are not supported -- as per
867 * the ACPI specification.
869 if (buffer_length < required_length) {
871 /* We need to create a new buffer */
873 new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
875 return_ACPI_STATUS(AE_NO_MEMORY);
879 * Copy the original data to the new buffer, starting
880 * at Byte zero. All unused (upper) bytes of the
883 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length);
885 buffer_length = required_length;
888 /* TBD: Move to common setup code */
890 /* Algo is limited to sizeof(u64), so cut the access_byte_width */
891 if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
892 obj_desc->common_field.access_byte_width = sizeof(u64);
895 access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
898 * Create the bitmasks used for bit insertion.
899 * Note: This if/else is used to bypass compiler differences with the
902 if (access_bit_width == ACPI_INTEGER_BIT_SIZE) {
903 width_mask = ACPI_UINT64_MAX;
905 width_mask = ACPI_MASK_BITS_ABOVE(access_bit_width);
909 ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
911 /* Compute the number of datums (access width data items) */
913 datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
916 field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
917 obj_desc->common_field.
918 start_field_bit_offset,
921 /* Get initial Datum from the input buffer */
923 ACPI_MEMCPY(&raw_datum, buffer,
924 ACPI_MIN(obj_desc->common_field.access_byte_width,
925 buffer_length - buffer_offset));
928 raw_datum << obj_desc->common_field.start_field_bit_offset;
930 /* Write the entire field */
932 for (i = 1; i < field_datum_count; i++) {
934 /* Write merged datum to the target field */
936 merged_datum &= mask;
937 status = acpi_ex_write_with_update_rule(obj_desc, mask,
940 if (ACPI_FAILURE(status)) {
944 field_offset += obj_desc->common_field.access_byte_width;
947 * Start new output datum by merging with previous input datum
950 * Note: Before the shift, check if the shift value will be larger than
951 * the integer size. If so, there is no need to perform the operation.
952 * This avoids the differences in behavior between different compilers
953 * concerning shift values larger than the target data width.
955 if ((access_bit_width -
956 obj_desc->common_field.start_field_bit_offset) <
957 ACPI_INTEGER_BIT_SIZE) {
959 raw_datum >> (access_bit_width -
960 obj_desc->common_field.
961 start_field_bit_offset);
968 if (i == datum_count) {
972 /* Get the next input datum from the buffer */
974 buffer_offset += obj_desc->common_field.access_byte_width;
975 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset,
976 ACPI_MIN(obj_desc->common_field.access_byte_width,
977 buffer_length - buffer_offset));
980 raw_datum << obj_desc->common_field.start_field_bit_offset;
983 /* Mask off any extra bits in the last datum */
985 buffer_tail_bits = (obj_desc->common_field.bit_length +
986 obj_desc->common_field.start_field_bit_offset) %
988 if (buffer_tail_bits) {
989 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
992 /* Write the last datum to the field */
994 merged_datum &= mask;
995 status = acpi_ex_write_with_update_rule(obj_desc,
1000 /* Free temporary buffer if we used one */
1003 ACPI_FREE(new_buffer);
1005 return_ACPI_STATUS(status);