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
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>
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 if (buffer_length
>= sizeof(u64
)) {
725 acpi_ex_field_datum_io(obj_desc
, 0, buffer
,
728 /* Use raw_datum (u64) to handle buffers < 64 bits */
731 acpi_ex_field_datum_io(obj_desc
, 0, &raw_datum
,
733 ACPI_MEMCPY(buffer
, &raw_datum
, buffer_length
);
736 return_ACPI_STATUS(status
);
739 /* TBD: Move to common setup code */
741 /* Field algorithm is limited to sizeof(u64), truncate if needed */
743 if (obj_desc
->common_field
.access_byte_width
> sizeof(u64
)) {
744 obj_desc
->common_field
.access_byte_width
= sizeof(u64
);
745 access_bit_width
= sizeof(u64
) * 8;
748 /* Compute the number of datums (access width data items) */
751 ACPI_ROUND_UP_TO(obj_desc
->common_field
.bit_length
,
754 field_datum_count
= ACPI_ROUND_UP_TO(obj_desc
->common_field
.bit_length
+
755 obj_desc
->common_field
.
756 start_field_bit_offset
,
759 /* Priming read from the field */
762 acpi_ex_field_datum_io(obj_desc
, field_offset
, &raw_datum
,
764 if (ACPI_FAILURE(status
)) {
765 return_ACPI_STATUS(status
);
768 raw_datum
>> obj_desc
->common_field
.start_field_bit_offset
;
770 /* Read the rest of the field */
772 for (i
= 1; i
< field_datum_count
; i
++) {
774 /* Get next input datum from the field */
776 field_offset
+= obj_desc
->common_field
.access_byte_width
;
777 status
= acpi_ex_field_datum_io(obj_desc
, field_offset
,
778 &raw_datum
, ACPI_READ
);
779 if (ACPI_FAILURE(status
)) {
780 return_ACPI_STATUS(status
);
784 * Merge with previous datum if necessary.
786 * Note: Before the shift, check if the shift value will be larger than
787 * the integer size. If so, there is no need to perform the operation.
788 * This avoids the differences in behavior between different compilers
789 * concerning shift values larger than the target data width.
791 if (access_bit_width
-
792 obj_desc
->common_field
.start_field_bit_offset
<
793 ACPI_INTEGER_BIT_SIZE
) {
795 raw_datum
<< (access_bit_width
-
796 obj_desc
->common_field
.
797 start_field_bit_offset
);
800 if (i
== datum_count
) {
804 /* Write merged datum to target buffer */
806 ACPI_MEMCPY(((char *)buffer
) + buffer_offset
, &merged_datum
,
807 ACPI_MIN(obj_desc
->common_field
.access_byte_width
,
808 buffer_length
- buffer_offset
));
810 buffer_offset
+= obj_desc
->common_field
.access_byte_width
;
812 raw_datum
>> obj_desc
->common_field
.start_field_bit_offset
;
815 /* Mask off any extra bits in the last datum */
817 buffer_tail_bits
= obj_desc
->common_field
.bit_length
% access_bit_width
;
818 if (buffer_tail_bits
) {
819 merged_datum
&= ACPI_MASK_BITS_ABOVE(buffer_tail_bits
);
822 /* Write the last datum to the buffer */
824 ACPI_MEMCPY(((char *)buffer
) + buffer_offset
, &merged_datum
,
825 ACPI_MIN(obj_desc
->common_field
.access_byte_width
,
826 buffer_length
- buffer_offset
));
828 return_ACPI_STATUS(AE_OK
);
831 /*******************************************************************************
833 * FUNCTION: acpi_ex_insert_into_field
835 * PARAMETERS: obj_desc - Field to be written
836 * buffer - Data to be written
837 * buffer_length - Length of Buffer
841 * DESCRIPTION: Store the Buffer contents into the given field
843 ******************************************************************************/
846 acpi_ex_insert_into_field(union acpi_operand_object
*obj_desc
,
847 void *buffer
, u32 buffer_length
)
855 u32 field_offset
= 0;
856 u32 buffer_offset
= 0;
857 u32 buffer_tail_bits
;
859 u32 field_datum_count
;
860 u32 access_bit_width
;
864 ACPI_FUNCTION_TRACE(ex_insert_into_field
);
866 /* Validate input buffer */
870 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc
->common_field
.bit_length
);
872 * We must have a buffer that is at least as long as the field
873 * we are writing to. This is because individual fields are
874 * indivisible and partial writes are not supported -- as per
875 * the ACPI specification.
877 if (buffer_length
< required_length
) {
879 /* We need to create a new buffer */
881 new_buffer
= ACPI_ALLOCATE_ZEROED(required_length
);
883 return_ACPI_STATUS(AE_NO_MEMORY
);
887 * Copy the original data to the new buffer, starting
888 * at Byte zero. All unused (upper) bytes of the
891 ACPI_MEMCPY((char *)new_buffer
, (char *)buffer
, buffer_length
);
893 buffer_length
= required_length
;
896 /* TBD: Move to common setup code */
898 /* Algo is limited to sizeof(u64), so cut the access_byte_width */
899 if (obj_desc
->common_field
.access_byte_width
> sizeof(u64
)) {
900 obj_desc
->common_field
.access_byte_width
= sizeof(u64
);
903 access_bit_width
= ACPI_MUL_8(obj_desc
->common_field
.access_byte_width
);
906 * Create the bitmasks used for bit insertion.
907 * Note: This if/else is used to bypass compiler differences with the
910 if (access_bit_width
== ACPI_INTEGER_BIT_SIZE
) {
911 width_mask
= ACPI_UINT64_MAX
;
913 width_mask
= ACPI_MASK_BITS_ABOVE(access_bit_width
);
917 ACPI_MASK_BITS_BELOW(obj_desc
->common_field
.start_field_bit_offset
);
919 /* Compute the number of datums (access width data items) */
921 datum_count
= ACPI_ROUND_UP_TO(obj_desc
->common_field
.bit_length
,
924 field_datum_count
= ACPI_ROUND_UP_TO(obj_desc
->common_field
.bit_length
+
925 obj_desc
->common_field
.
926 start_field_bit_offset
,
929 /* Get initial Datum from the input buffer */
931 ACPI_MEMCPY(&raw_datum
, buffer
,
932 ACPI_MIN(obj_desc
->common_field
.access_byte_width
,
933 buffer_length
- buffer_offset
));
936 raw_datum
<< obj_desc
->common_field
.start_field_bit_offset
;
938 /* Write the entire field */
940 for (i
= 1; i
< field_datum_count
; i
++) {
942 /* Write merged datum to the target field */
944 merged_datum
&= mask
;
945 status
= acpi_ex_write_with_update_rule(obj_desc
, mask
,
948 if (ACPI_FAILURE(status
)) {
952 field_offset
+= obj_desc
->common_field
.access_byte_width
;
955 * Start new output datum by merging with previous input datum
958 * Note: Before the shift, check if the shift value will be larger than
959 * the integer size. If so, there is no need to perform the operation.
960 * This avoids the differences in behavior between different compilers
961 * concerning shift values larger than the target data width.
963 if ((access_bit_width
-
964 obj_desc
->common_field
.start_field_bit_offset
) <
965 ACPI_INTEGER_BIT_SIZE
) {
967 raw_datum
>> (access_bit_width
-
968 obj_desc
->common_field
.
969 start_field_bit_offset
);
976 if (i
== datum_count
) {
980 /* Get the next input datum from the buffer */
982 buffer_offset
+= obj_desc
->common_field
.access_byte_width
;
983 ACPI_MEMCPY(&raw_datum
, ((char *)buffer
) + buffer_offset
,
984 ACPI_MIN(obj_desc
->common_field
.access_byte_width
,
985 buffer_length
- buffer_offset
));
988 raw_datum
<< obj_desc
->common_field
.start_field_bit_offset
;
991 /* Mask off any extra bits in the last datum */
993 buffer_tail_bits
= (obj_desc
->common_field
.bit_length
+
994 obj_desc
->common_field
.start_field_bit_offset
) %
996 if (buffer_tail_bits
) {
997 mask
&= ACPI_MASK_BITS_ABOVE(buffer_tail_bits
);
1000 /* Write the last datum to the field */
1002 merged_datum
&= mask
;
1003 status
= acpi_ex_write_with_update_rule(obj_desc
,
1008 /* Free temporary buffer if we used one */
1011 ACPI_FREE(new_buffer
);
1013 return_ACPI_STATUS(status
);