Merge branch 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied...
[linux-2.6] / drivers / acpi / acpica / exfldio.c
1 /******************************************************************************
2  *
3  * Module Name: exfldio - Aml Field I/O
4  *
5  *****************************************************************************/
6
7 /*
8  * Copyright (C) 2000 - 2008, Intel Corp.
9  * All rights reserved.
10  *
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.
25  *
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.
29  *
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.
42  */
43
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"
50
51 #define _COMPONENT          ACPI_EXECUTER
52 ACPI_MODULE_NAME("exfldio")
53
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                        acpi_integer * value, u32 read_write);
59
60 static u8
61 acpi_ex_register_overflow(union acpi_operand_object *obj_desc,
62                           acpi_integer value);
63
64 static acpi_status
65 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
66                      u32 field_datum_byte_offset);
67
68 /*******************************************************************************
69  *
70  * FUNCTION:    acpi_ex_setup_region
71  *
72  * PARAMETERS:  obj_desc                - Field to be read or written
73  *              field_datum_byte_offset - Byte offset of this datum within the
74  *                                        parent field
75  *
76  * RETURN:      Status
77  *
78  * DESCRIPTION: Common processing for acpi_ex_extract_from_field and
79  *              acpi_ex_insert_into_field. Initialize the Region if necessary and
80  *              validate the request.
81  *
82  ******************************************************************************/
83
84 static acpi_status
85 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
86                      u32 field_datum_byte_offset)
87 {
88         acpi_status status = AE_OK;
89         union acpi_operand_object *rgn_desc;
90
91         ACPI_FUNCTION_TRACE_U32(ex_setup_region, field_datum_byte_offset);
92
93         rgn_desc = obj_desc->common_field.region_obj;
94
95         /* We must have a valid region */
96
97         if (rgn_desc->common.type != ACPI_TYPE_REGION) {
98                 ACPI_ERROR((AE_INFO, "Needed Region, found type %X (%s)",
99                             rgn_desc->common.type,
100                             acpi_ut_get_object_type_name(rgn_desc)));
101
102                 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
103         }
104
105         /*
106          * If the Region Address and Length have not been previously evaluated,
107          * evaluate them now and save the results.
108          */
109         if (!(rgn_desc->common.flags & AOPOBJ_DATA_VALID)) {
110                 status = acpi_ds_get_region_arguments(rgn_desc);
111                 if (ACPI_FAILURE(status)) {
112                         return_ACPI_STATUS(status);
113                 }
114         }
115
116         /*
117          * Exit now for SMBus address space, it has a non-linear address space
118          * and the request cannot be directly validated
119          */
120         if (rgn_desc->region.space_id == ACPI_ADR_SPACE_SMBUS) {
121
122                 /* SMBus has a non-linear address space */
123
124                 return_ACPI_STATUS(AE_OK);
125         }
126 #ifdef ACPI_UNDER_DEVELOPMENT
127         /*
128          * If the Field access is any_acc, we can now compute the optimal
129          * access (because we know know the length of the parent region)
130          */
131         if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
132                 if (ACPI_FAILURE(status)) {
133                         return_ACPI_STATUS(status);
134                 }
135         }
136 #endif
137
138         /*
139          * Validate the request.  The entire request from the byte offset for a
140          * length of one field datum (access width) must fit within the region.
141          * (Region length is specified in bytes)
142          */
143         if (rgn_desc->region.length <
144             (obj_desc->common_field.base_byte_offset +
145              field_datum_byte_offset +
146              obj_desc->common_field.access_byte_width)) {
147                 if (acpi_gbl_enable_interpreter_slack) {
148                         /*
149                          * Slack mode only:  We will go ahead and allow access to this
150                          * field if it is within the region length rounded up to the next
151                          * access width boundary. acpi_size cast for 64-bit compile.
152                          */
153                         if (ACPI_ROUND_UP(rgn_desc->region.length,
154                                           obj_desc->common_field.
155                                           access_byte_width) >=
156                             ((acpi_size) obj_desc->common_field.
157                              base_byte_offset +
158                              obj_desc->common_field.access_byte_width +
159                              field_datum_byte_offset)) {
160                                 return_ACPI_STATUS(AE_OK);
161                         }
162                 }
163
164                 if (rgn_desc->region.length <
165                     obj_desc->common_field.access_byte_width) {
166                         /*
167                          * This is the case where the access_type (acc_word, etc.) is wider
168                          * than the region itself.  For example, a region of length one
169                          * byte, and a field with Dword access specified.
170                          */
171                         ACPI_ERROR((AE_INFO,
172                                     "Field [%4.4s] access width (%d bytes) too large for region [%4.4s] (length %X)",
173                                     acpi_ut_get_node_name(obj_desc->
174                                                           common_field.node),
175                                     obj_desc->common_field.access_byte_width,
176                                     acpi_ut_get_node_name(rgn_desc->region.
177                                                           node),
178                                     rgn_desc->region.length));
179                 }
180
181                 /*
182                  * Offset rounded up to next multiple of field width
183                  * exceeds region length, indicate an error
184                  */
185                 ACPI_ERROR((AE_INFO,
186                             "Field [%4.4s] Base+Offset+Width %X+%X+%X is beyond end of region [%4.4s] (length %X)",
187                             acpi_ut_get_node_name(obj_desc->common_field.node),
188                             obj_desc->common_field.base_byte_offset,
189                             field_datum_byte_offset,
190                             obj_desc->common_field.access_byte_width,
191                             acpi_ut_get_node_name(rgn_desc->region.node),
192                             rgn_desc->region.length));
193
194                 return_ACPI_STATUS(AE_AML_REGION_LIMIT);
195         }
196
197         return_ACPI_STATUS(AE_OK);
198 }
199
200 /*******************************************************************************
201  *
202  * FUNCTION:    acpi_ex_access_region
203  *
204  * PARAMETERS:  obj_desc                - Field to be read
205  *              field_datum_byte_offset - Byte offset of this datum within the
206  *                                        parent field
207  *              Value                   - Where to store value (must at least
208  *                                        the size of acpi_integer)
209  *              Function                - Read or Write flag plus other region-
210  *                                        dependent flags
211  *
212  * RETURN:      Status
213  *
214  * DESCRIPTION: Read or Write a single field datum to an Operation Region.
215  *
216  ******************************************************************************/
217
218 acpi_status
219 acpi_ex_access_region(union acpi_operand_object *obj_desc,
220                       u32 field_datum_byte_offset,
221                       acpi_integer * value, u32 function)
222 {
223         acpi_status status;
224         union acpi_operand_object *rgn_desc;
225         acpi_physical_address address;
226
227         ACPI_FUNCTION_TRACE(ex_access_region);
228
229         /*
230          * Ensure that the region operands are fully evaluated and verify
231          * the validity of the request
232          */
233         status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset);
234         if (ACPI_FAILURE(status)) {
235                 return_ACPI_STATUS(status);
236         }
237
238         /*
239          * The physical address of this field datum is:
240          *
241          * 1) The base of the region, plus
242          * 2) The base offset of the field, plus
243          * 3) The current offset into the field
244          */
245         rgn_desc = obj_desc->common_field.region_obj;
246         address = rgn_desc->region.address +
247             obj_desc->common_field.base_byte_offset + field_datum_byte_offset;
248
249         if ((function & ACPI_IO_MASK) == ACPI_READ) {
250                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
251         } else {
252                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
253         }
254
255         ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
256                               " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n",
257                               acpi_ut_get_region_name(rgn_desc->region.
258                                                       space_id),
259                               rgn_desc->region.space_id,
260                               obj_desc->common_field.access_byte_width,
261                               obj_desc->common_field.base_byte_offset,
262                               field_datum_byte_offset, ACPI_CAST_PTR(void,
263                                                                      address)));
264
265         /* Invoke the appropriate address_space/op_region handler */
266
267         status = acpi_ev_address_space_dispatch(rgn_desc, function,
268                                                 address,
269                                                 ACPI_MUL_8(obj_desc->
270                                                            common_field.
271                                                            access_byte_width),
272                                                 value);
273
274         if (ACPI_FAILURE(status)) {
275                 if (status == AE_NOT_IMPLEMENTED) {
276                         ACPI_ERROR((AE_INFO,
277                                     "Region %s(%X) not implemented",
278                                     acpi_ut_get_region_name(rgn_desc->region.
279                                                             space_id),
280                                     rgn_desc->region.space_id));
281                 } else if (status == AE_NOT_EXIST) {
282                         ACPI_ERROR((AE_INFO,
283                                     "Region %s(%X) has no handler",
284                                     acpi_ut_get_region_name(rgn_desc->region.
285                                                             space_id),
286                                     rgn_desc->region.space_id));
287                 }
288         }
289
290         return_ACPI_STATUS(status);
291 }
292
293 /*******************************************************************************
294  *
295  * FUNCTION:    acpi_ex_register_overflow
296  *
297  * PARAMETERS:  obj_desc                - Register(Field) to be written
298  *              Value                   - Value to be stored
299  *
300  * RETURN:      TRUE if value overflows the field, FALSE otherwise
301  *
302  * DESCRIPTION: Check if a value is out of range of the field being written.
303  *              Used to check if the values written to Index and Bank registers
304  *              are out of range.  Normally, the value is simply truncated
305  *              to fit the field, but this case is most likely a serious
306  *              coding error in the ASL.
307  *
308  ******************************************************************************/
309
310 static u8
311 acpi_ex_register_overflow(union acpi_operand_object *obj_desc,
312                           acpi_integer value)
313 {
314
315         if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
316                 /*
317                  * The field is large enough to hold the maximum integer, so we can
318                  * never overflow it.
319                  */
320                 return (FALSE);
321         }
322
323         if (value >= ((acpi_integer) 1 << obj_desc->common_field.bit_length)) {
324                 /*
325                  * The Value is larger than the maximum value that can fit into
326                  * the register.
327                  */
328                 return (TRUE);
329         }
330
331         /* The Value will fit into the field with no truncation */
332
333         return (FALSE);
334 }
335
336 /*******************************************************************************
337  *
338  * FUNCTION:    acpi_ex_field_datum_io
339  *
340  * PARAMETERS:  obj_desc                - Field to be read
341  *              field_datum_byte_offset - Byte offset of this datum within the
342  *                                        parent field
343  *              Value                   - Where to store value (must be 64 bits)
344  *              read_write              - Read or Write flag
345  *
346  * RETURN:      Status
347  *
348  * DESCRIPTION: Read or Write a single datum of a field.  The field_type is
349  *              demultiplexed here to handle the different types of fields
350  *              (buffer_field, region_field, index_field, bank_field)
351  *
352  ******************************************************************************/
353
354 static acpi_status
355 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
356                        u32 field_datum_byte_offset,
357                        acpi_integer * value, u32 read_write)
358 {
359         acpi_status status;
360         acpi_integer local_value;
361
362         ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
363
364         if (read_write == ACPI_READ) {
365                 if (!value) {
366                         local_value = 0;
367
368                         /* To support reads without saving return value */
369                         value = &local_value;
370                 }
371
372                 /* Clear the entire return buffer first, [Very Important!] */
373
374                 *value = 0;
375         }
376
377         /*
378          * The four types of fields are:
379          *
380          * buffer_field - Read/write from/to a Buffer
381          * region_field - Read/write from/to a Operation Region.
382          * bank_field  - Write to a Bank Register, then read/write from/to an
383          *               operation_region
384          * index_field - Write to an Index Register, then read/write from/to a
385          *               Data Register
386          */
387         switch (obj_desc->common.type) {
388         case ACPI_TYPE_BUFFER_FIELD:
389                 /*
390                  * If the buffer_field arguments have not been previously evaluated,
391                  * evaluate them now and save the results.
392                  */
393                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
394                         status = acpi_ds_get_buffer_field_arguments(obj_desc);
395                         if (ACPI_FAILURE(status)) {
396                                 return_ACPI_STATUS(status);
397                         }
398                 }
399
400                 if (read_write == ACPI_READ) {
401                         /*
402                          * Copy the data from the source buffer.
403                          * Length is the field width in bytes.
404                          */
405                         ACPI_MEMCPY(value,
406                                     (obj_desc->buffer_field.buffer_obj)->buffer.
407                                     pointer +
408                                     obj_desc->buffer_field.base_byte_offset +
409                                     field_datum_byte_offset,
410                                     obj_desc->common_field.access_byte_width);
411                 } else {
412                         /*
413                          * Copy the data to the target buffer.
414                          * Length is the field width in bytes.
415                          */
416                         ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer.
417                                     pointer +
418                                     obj_desc->buffer_field.base_byte_offset +
419                                     field_datum_byte_offset, value,
420                                     obj_desc->common_field.access_byte_width);
421                 }
422
423                 status = AE_OK;
424                 break;
425
426         case ACPI_TYPE_LOCAL_BANK_FIELD:
427
428                 /*
429                  * Ensure that the bank_value is not beyond the capacity of
430                  * the register
431                  */
432                 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
433                                               (acpi_integer) obj_desc->
434                                               bank_field.value)) {
435                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
436                 }
437
438                 /*
439                  * For bank_fields, we must write the bank_value to the bank_register
440                  * (itself a region_field) before we can access the data.
441                  */
442                 status =
443                     acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
444                                               &obj_desc->bank_field.value,
445                                               sizeof(obj_desc->bank_field.
446                                                      value));
447                 if (ACPI_FAILURE(status)) {
448                         return_ACPI_STATUS(status);
449                 }
450
451                 /*
452                  * Now that the Bank has been selected, fall through to the
453                  * region_field case and write the datum to the Operation Region
454                  */
455
456                 /*lint -fallthrough */
457
458         case ACPI_TYPE_LOCAL_REGION_FIELD:
459                 /*
460                  * For simple region_fields, we just directly access the owning
461                  * Operation Region.
462                  */
463                 status =
464                     acpi_ex_access_region(obj_desc, field_datum_byte_offset,
465                                           value, read_write);
466                 break;
467
468         case ACPI_TYPE_LOCAL_INDEX_FIELD:
469
470                 /*
471                  * Ensure that the index_value is not beyond the capacity of
472                  * the register
473                  */
474                 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
475                                               (acpi_integer) obj_desc->
476                                               index_field.value)) {
477                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
478                 }
479
480                 /* Write the index value to the index_register (itself a region_field) */
481
482                 field_datum_byte_offset += obj_desc->index_field.value;
483
484                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
485                                   "Write to Index Register: Value %8.8X\n",
486                                   field_datum_byte_offset));
487
488                 status =
489                     acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
490                                               &field_datum_byte_offset,
491                                               sizeof(field_datum_byte_offset));
492                 if (ACPI_FAILURE(status)) {
493                         return_ACPI_STATUS(status);
494                 }
495
496                 if (read_write == ACPI_READ) {
497
498                         /* Read the datum from the data_register */
499
500                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
501                                           "Read from Data Register\n"));
502
503                         status =
504                             acpi_ex_extract_from_field(obj_desc->index_field.
505                                                        data_obj, value,
506                                                        sizeof(acpi_integer));
507                 } else {
508                         /* Write the datum to the data_register */
509
510                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
511                                           "Write to Data Register: Value %8.8X%8.8X\n",
512                                           ACPI_FORMAT_UINT64(*value)));
513
514                         status =
515                             acpi_ex_insert_into_field(obj_desc->index_field.
516                                                       data_obj, value,
517                                                       sizeof(acpi_integer));
518                 }
519                 break;
520
521         default:
522
523                 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %X",
524                             obj_desc->common.type));
525                 status = AE_AML_INTERNAL;
526                 break;
527         }
528
529         if (ACPI_SUCCESS(status)) {
530                 if (read_write == ACPI_READ) {
531                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
532                                           "Value Read %8.8X%8.8X, Width %d\n",
533                                           ACPI_FORMAT_UINT64(*value),
534                                           obj_desc->common_field.
535                                           access_byte_width));
536                 } else {
537                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
538                                           "Value Written %8.8X%8.8X, Width %d\n",
539                                           ACPI_FORMAT_UINT64(*value),
540                                           obj_desc->common_field.
541                                           access_byte_width));
542                 }
543         }
544
545         return_ACPI_STATUS(status);
546 }
547
548 /*******************************************************************************
549  *
550  * FUNCTION:    acpi_ex_write_with_update_rule
551  *
552  * PARAMETERS:  obj_desc                - Field to be written
553  *              Mask                    - bitmask within field datum
554  *              field_value             - Value to write
555  *              field_datum_byte_offset - Offset of datum within field
556  *
557  * RETURN:      Status
558  *
559  * DESCRIPTION: Apply the field update rule to a field write
560  *
561  ******************************************************************************/
562
563 acpi_status
564 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc,
565                                acpi_integer mask,
566                                acpi_integer field_value,
567                                u32 field_datum_byte_offset)
568 {
569         acpi_status status = AE_OK;
570         acpi_integer merged_value;
571         acpi_integer current_value;
572
573         ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask);
574
575         /* Start with the new bits  */
576
577         merged_value = field_value;
578
579         /* If the mask is all ones, we don't need to worry about the update rule */
580
581         if (mask != ACPI_INTEGER_MAX) {
582
583                 /* Decode the update rule */
584
585                 switch (obj_desc->common_field.
586                         field_flags & AML_FIELD_UPDATE_RULE_MASK) {
587                 case AML_FIELD_UPDATE_PRESERVE:
588                         /*
589                          * Check if update rule needs to be applied (not if mask is all
590                          * ones)  The left shift drops the bits we want to ignore.
591                          */
592                         if ((~mask << (ACPI_MUL_8(sizeof(mask)) -
593                                        ACPI_MUL_8(obj_desc->common_field.
594                                                   access_byte_width))) != 0) {
595                                 /*
596                                  * Read the current contents of the byte/word/dword containing
597                                  * the field, and merge with the new field value.
598                                  */
599                                 status =
600                                     acpi_ex_field_datum_io(obj_desc,
601                                                            field_datum_byte_offset,
602                                                            &current_value,
603                                                            ACPI_READ);
604                                 if (ACPI_FAILURE(status)) {
605                                         return_ACPI_STATUS(status);
606                                 }
607
608                                 merged_value |= (current_value & ~mask);
609                         }
610                         break;
611
612                 case AML_FIELD_UPDATE_WRITE_AS_ONES:
613
614                         /* Set positions outside the field to all ones */
615
616                         merged_value |= ~mask;
617                         break;
618
619                 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
620
621                         /* Set positions outside the field to all zeros */
622
623                         merged_value &= mask;
624                         break;
625
626                 default:
627
628                         ACPI_ERROR((AE_INFO,
629                                     "Unknown UpdateRule value: %X",
630                                     (obj_desc->common_field.
631                                      field_flags &
632                                      AML_FIELD_UPDATE_RULE_MASK)));
633                         return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
634                 }
635         }
636
637         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
638                           "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
639                           ACPI_FORMAT_UINT64(mask),
640                           field_datum_byte_offset,
641                           obj_desc->common_field.access_byte_width,
642                           ACPI_FORMAT_UINT64(field_value),
643                           ACPI_FORMAT_UINT64(merged_value)));
644
645         /* Write the merged value */
646
647         status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset,
648                                         &merged_value, ACPI_WRITE);
649
650         return_ACPI_STATUS(status);
651 }
652
653 /*******************************************************************************
654  *
655  * FUNCTION:    acpi_ex_extract_from_field
656  *
657  * PARAMETERS:  obj_desc            - Field to be read
658  *              Buffer              - Where to store the field data
659  *              buffer_length       - Length of Buffer
660  *
661  * RETURN:      Status
662  *
663  * DESCRIPTION: Retrieve the current value of the given field
664  *
665  ******************************************************************************/
666
667 acpi_status
668 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
669                            void *buffer, u32 buffer_length)
670 {
671         acpi_status status;
672         acpi_integer raw_datum;
673         acpi_integer merged_datum;
674         u32 field_offset = 0;
675         u32 buffer_offset = 0;
676         u32 buffer_tail_bits;
677         u32 datum_count;
678         u32 field_datum_count;
679         u32 i;
680
681         ACPI_FUNCTION_TRACE(ex_extract_from_field);
682
683         /* Validate target buffer and clear it */
684
685         if (buffer_length <
686             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
687                 ACPI_ERROR((AE_INFO,
688                             "Field size %X (bits) is too large for buffer (%X)",
689                             obj_desc->common_field.bit_length, buffer_length));
690
691                 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
692         }
693         ACPI_MEMSET(buffer, 0, buffer_length);
694
695         /* Compute the number of datums (access width data items) */
696
697         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
698                                        obj_desc->common_field.access_bit_width);
699         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
700                                              obj_desc->common_field.
701                                              start_field_bit_offset,
702                                              obj_desc->common_field.
703                                              access_bit_width);
704
705         /* Priming read from the field */
706
707         status =
708             acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
709                                    ACPI_READ);
710         if (ACPI_FAILURE(status)) {
711                 return_ACPI_STATUS(status);
712         }
713         merged_datum =
714             raw_datum >> obj_desc->common_field.start_field_bit_offset;
715
716         /* Read the rest of the field */
717
718         for (i = 1; i < field_datum_count; i++) {
719
720                 /* Get next input datum from the field */
721
722                 field_offset += obj_desc->common_field.access_byte_width;
723                 status = acpi_ex_field_datum_io(obj_desc, field_offset,
724                                                 &raw_datum, ACPI_READ);
725                 if (ACPI_FAILURE(status)) {
726                         return_ACPI_STATUS(status);
727                 }
728
729                 /*
730                  * Merge with previous datum if necessary.
731                  *
732                  * Note: Before the shift, check if the shift value will be larger than
733                  * the integer size. If so, there is no need to perform the operation.
734                  * This avoids the differences in behavior between different compilers
735                  * concerning shift values larger than the target data width.
736                  */
737                 if ((obj_desc->common_field.access_bit_width -
738                      obj_desc->common_field.start_field_bit_offset) <
739                     ACPI_INTEGER_BIT_SIZE) {
740                         merged_datum |=
741                             raw_datum << (obj_desc->common_field.
742                                           access_bit_width -
743                                           obj_desc->common_field.
744                                           start_field_bit_offset);
745                 }
746
747                 if (i == datum_count) {
748                         break;
749                 }
750
751                 /* Write merged datum to target buffer */
752
753                 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
754                             ACPI_MIN(obj_desc->common_field.access_byte_width,
755                                      buffer_length - buffer_offset));
756
757                 buffer_offset += obj_desc->common_field.access_byte_width;
758                 merged_datum =
759                     raw_datum >> obj_desc->common_field.start_field_bit_offset;
760         }
761
762         /* Mask off any extra bits in the last datum */
763
764         buffer_tail_bits = obj_desc->common_field.bit_length %
765             obj_desc->common_field.access_bit_width;
766         if (buffer_tail_bits) {
767                 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
768         }
769
770         /* Write the last datum to the buffer */
771
772         ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
773                     ACPI_MIN(obj_desc->common_field.access_byte_width,
774                              buffer_length - buffer_offset));
775
776         return_ACPI_STATUS(AE_OK);
777 }
778
779 /*******************************************************************************
780  *
781  * FUNCTION:    acpi_ex_insert_into_field
782  *
783  * PARAMETERS:  obj_desc            - Field to be written
784  *              Buffer              - Data to be written
785  *              buffer_length       - Length of Buffer
786  *
787  * RETURN:      Status
788  *
789  * DESCRIPTION: Store the Buffer contents into the given field
790  *
791  ******************************************************************************/
792
793 acpi_status
794 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
795                           void *buffer, u32 buffer_length)
796 {
797         acpi_status status;
798         acpi_integer mask;
799         acpi_integer width_mask;
800         acpi_integer merged_datum;
801         acpi_integer raw_datum = 0;
802         u32 field_offset = 0;
803         u32 buffer_offset = 0;
804         u32 buffer_tail_bits;
805         u32 datum_count;
806         u32 field_datum_count;
807         u32 i;
808         u32 required_length;
809         void *new_buffer;
810
811         ACPI_FUNCTION_TRACE(ex_insert_into_field);
812
813         /* Validate input buffer */
814
815         new_buffer = NULL;
816         required_length =
817             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
818         /*
819          * We must have a buffer that is at least as long as the field
820          * we are writing to.  This is because individual fields are
821          * indivisible and partial writes are not supported -- as per
822          * the ACPI specification.
823          */
824         if (buffer_length < required_length) {
825
826                 /* We need to create a new buffer */
827
828                 new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
829                 if (!new_buffer) {
830                         return_ACPI_STATUS(AE_NO_MEMORY);
831                 }
832
833                 /*
834                  * Copy the original data to the new buffer, starting
835                  * at Byte zero.  All unused (upper) bytes of the
836                  * buffer will be 0.
837                  */
838                 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length);
839                 buffer = new_buffer;
840                 buffer_length = required_length;
841         }
842
843         /*
844          * Create the bitmasks used for bit insertion.
845          * Note: This if/else is used to bypass compiler differences with the
846          * shift operator
847          */
848         if (obj_desc->common_field.access_bit_width == ACPI_INTEGER_BIT_SIZE) {
849                 width_mask = ACPI_INTEGER_MAX;
850         } else {
851                 width_mask =
852                     ACPI_MASK_BITS_ABOVE(obj_desc->common_field.
853                                          access_bit_width);
854         }
855
856         mask = width_mask &
857             ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
858
859         /* Compute the number of datums (access width data items) */
860
861         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
862                                        obj_desc->common_field.access_bit_width);
863
864         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
865                                              obj_desc->common_field.
866                                              start_field_bit_offset,
867                                              obj_desc->common_field.
868                                              access_bit_width);
869
870         /* Get initial Datum from the input buffer */
871
872         ACPI_MEMCPY(&raw_datum, buffer,
873                     ACPI_MIN(obj_desc->common_field.access_byte_width,
874                              buffer_length - buffer_offset));
875
876         merged_datum =
877             raw_datum << obj_desc->common_field.start_field_bit_offset;
878
879         /* Write the entire field */
880
881         for (i = 1; i < field_datum_count; i++) {
882
883                 /* Write merged datum to the target field */
884
885                 merged_datum &= mask;
886                 status = acpi_ex_write_with_update_rule(obj_desc, mask,
887                                                         merged_datum,
888                                                         field_offset);
889                 if (ACPI_FAILURE(status)) {
890                         goto exit;
891                 }
892
893                 field_offset += obj_desc->common_field.access_byte_width;
894
895                 /*
896                  * Start new output datum by merging with previous input datum
897                  * if necessary.
898                  *
899                  * Note: Before the shift, check if the shift value will be larger than
900                  * the integer size. If so, there is no need to perform the operation.
901                  * This avoids the differences in behavior between different compilers
902                  * concerning shift values larger than the target data width.
903                  */
904                 if ((obj_desc->common_field.access_bit_width -
905                      obj_desc->common_field.start_field_bit_offset) <
906                     ACPI_INTEGER_BIT_SIZE) {
907                         merged_datum =
908                             raw_datum >> (obj_desc->common_field.
909                                           access_bit_width -
910                                           obj_desc->common_field.
911                                           start_field_bit_offset);
912                 } else {
913                         merged_datum = 0;
914                 }
915
916                 mask = width_mask;
917
918                 if (i == datum_count) {
919                         break;
920                 }
921
922                 /* Get the next input datum from the buffer */
923
924                 buffer_offset += obj_desc->common_field.access_byte_width;
925                 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset,
926                             ACPI_MIN(obj_desc->common_field.access_byte_width,
927                                      buffer_length - buffer_offset));
928                 merged_datum |=
929                     raw_datum << obj_desc->common_field.start_field_bit_offset;
930         }
931
932         /* Mask off any extra bits in the last datum */
933
934         buffer_tail_bits = (obj_desc->common_field.bit_length +
935                             obj_desc->common_field.start_field_bit_offset) %
936             obj_desc->common_field.access_bit_width;
937         if (buffer_tail_bits) {
938                 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
939         }
940
941         /* Write the last datum to the field */
942
943         merged_datum &= mask;
944         status = acpi_ex_write_with_update_rule(obj_desc,
945                                                 mask, merged_datum,
946                                                 field_offset);
947
948       exit:
949         /* Free temporary buffer if we used one */
950
951         if (new_buffer) {
952                 ACPI_FREE(new_buffer);
953         }
954         return_ACPI_STATUS(status);
955 }