Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/pci-2.6
[linux-2.6] / drivers / acpi / executer / exfldio.c
1 /******************************************************************************
2  *
3  * Module Name: exfldio - Aml Field I/O
4  *
5  *****************************************************************************/
6
7 /*
8  * Copyright (C) 2000 - 2007, R. Byron Moore
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 <acpi/acinterp.h>
46 #include <acpi/amlcode.h>
47 #include <acpi/acevents.h>
48 #include <acpi/acdispat.h>
49
50 #define _COMPONENT          ACPI_EXECUTER
51 ACPI_MODULE_NAME("exfldio")
52
53 /* Local prototypes */
54 static acpi_status
55 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
56                        u32 field_datum_byte_offset,
57                        acpi_integer * value, u32 read_write);
58
59 static u8
60 acpi_ex_register_overflow(union acpi_operand_object *obj_desc,
61                           acpi_integer value);
62
63 static acpi_status
64 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
65                      u32 field_datum_byte_offset);
66
67 /*******************************************************************************
68  *
69  * FUNCTION:    acpi_ex_setup_region
70  *
71  * PARAMETERS:  obj_desc                - Field to be read or written
72  *              field_datum_byte_offset - Byte offset of this datum within the
73  *                                        parent field
74  *
75  * RETURN:      Status
76  *
77  * DESCRIPTION: Common processing for acpi_ex_extract_from_field and
78  *              acpi_ex_insert_into_field. Initialize the Region if necessary and
79  *              validate the request.
80  *
81  ******************************************************************************/
82
83 static acpi_status
84 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
85                      u32 field_datum_byte_offset)
86 {
87         acpi_status status = AE_OK;
88         union acpi_operand_object *rgn_desc;
89
90         ACPI_FUNCTION_TRACE_U32(ex_setup_region, field_datum_byte_offset);
91
92         rgn_desc = obj_desc->common_field.region_obj;
93
94         /* We must have a valid region */
95
96         if (ACPI_GET_OBJECT_TYPE(rgn_desc) != ACPI_TYPE_REGION) {
97                 ACPI_ERROR((AE_INFO, "Needed Region, found type %X (%s)",
98                             ACPI_GET_OBJECT_TYPE(rgn_desc),
99                             acpi_ut_get_object_type_name(rgn_desc)));
100
101                 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
102         }
103
104         /*
105          * If the Region Address and Length have not been previously evaluated,
106          * evaluate them now and save the results.
107          */
108         if (!(rgn_desc->common.flags & AOPOBJ_DATA_VALID)) {
109                 status = acpi_ds_get_region_arguments(rgn_desc);
110                 if (ACPI_FAILURE(status)) {
111                         return_ACPI_STATUS(status);
112                 }
113         }
114
115         /* Exit if Address/Length have been disallowed by the host OS */
116
117         if (rgn_desc->common.flags & AOPOBJ_INVALID) {
118                 return_ACPI_STATUS(AE_AML_ILLEGAL_ADDRESS);
119         }
120
121         /*
122          * Exit now for SMBus address space, it has a non-linear address space
123          * and the request cannot be directly validated
124          */
125         if (rgn_desc->region.space_id == ACPI_ADR_SPACE_SMBUS) {
126
127                 /* SMBus has a non-linear address space */
128
129                 return_ACPI_STATUS(AE_OK);
130         }
131 #ifdef ACPI_UNDER_DEVELOPMENT
132         /*
133          * If the Field access is any_acc, we can now compute the optimal
134          * access (because we know know the length of the parent region)
135          */
136         if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
137                 if (ACPI_FAILURE(status)) {
138                         return_ACPI_STATUS(status);
139                 }
140         }
141 #endif
142
143         /*
144          * Validate the request.  The entire request from the byte offset for a
145          * length of one field datum (access width) must fit within the region.
146          * (Region length is specified in bytes)
147          */
148         if (rgn_desc->region.length <
149             (obj_desc->common_field.base_byte_offset +
150              field_datum_byte_offset +
151              obj_desc->common_field.access_byte_width)) {
152                 if (acpi_gbl_enable_interpreter_slack) {
153                         /*
154                          * Slack mode only:  We will go ahead and allow access to this
155                          * field if it is within the region length rounded up to the next
156                          * access width boundary.
157                          */
158                         if (ACPI_ROUND_UP(rgn_desc->region.length,
159                                           obj_desc->common_field.
160                                           access_byte_width) >=
161                             (obj_desc->common_field.base_byte_offset +
162                              (acpi_native_uint) obj_desc->common_field.
163                              access_byte_width + field_datum_byte_offset)) {
164                                 return_ACPI_STATUS(AE_OK);
165                         }
166                 }
167
168                 if (rgn_desc->region.length <
169                     obj_desc->common_field.access_byte_width) {
170                         /*
171                          * This is the case where the access_type (acc_word, etc.) is wider
172                          * than the region itself.  For example, a region of length one
173                          * byte, and a field with Dword access specified.
174                          */
175                         ACPI_ERROR((AE_INFO,
176                                     "Field [%4.4s] access width (%d bytes) too large for region [%4.4s] (length %X)",
177                                     acpi_ut_get_node_name(obj_desc->
178                                                           common_field.node),
179                                     obj_desc->common_field.access_byte_width,
180                                     acpi_ut_get_node_name(rgn_desc->region.
181                                                           node),
182                                     rgn_desc->region.length));
183                 }
184
185                 /*
186                  * Offset rounded up to next multiple of field width
187                  * exceeds region length, indicate an error
188                  */
189                 ACPI_ERROR((AE_INFO,
190                             "Field [%4.4s] Base+Offset+Width %X+%X+%X is beyond end of region [%4.4s] (length %X)",
191                             acpi_ut_get_node_name(obj_desc->common_field.node),
192                             obj_desc->common_field.base_byte_offset,
193                             field_datum_byte_offset,
194                             obj_desc->common_field.access_byte_width,
195                             acpi_ut_get_node_name(rgn_desc->region.node),
196                             rgn_desc->region.length));
197
198                 return_ACPI_STATUS(AE_AML_REGION_LIMIT);
199         }
200
201         return_ACPI_STATUS(AE_OK);
202 }
203
204 /*******************************************************************************
205  *
206  * FUNCTION:    acpi_ex_access_region
207  *
208  * PARAMETERS:  obj_desc                - Field to be read
209  *              field_datum_byte_offset - Byte offset of this datum within the
210  *                                        parent field
211  *              Value                   - Where to store value (must at least
212  *                                        the size of acpi_integer)
213  *              Function                - Read or Write flag plus other region-
214  *                                        dependent flags
215  *
216  * RETURN:      Status
217  *
218  * DESCRIPTION: Read or Write a single field datum to an Operation Region.
219  *
220  ******************************************************************************/
221
222 acpi_status
223 acpi_ex_access_region(union acpi_operand_object *obj_desc,
224                       u32 field_datum_byte_offset,
225                       acpi_integer * value, u32 function)
226 {
227         acpi_status status;
228         union acpi_operand_object *rgn_desc;
229         acpi_physical_address address;
230
231         ACPI_FUNCTION_TRACE(ex_access_region);
232
233         /*
234          * Ensure that the region operands are fully evaluated and verify
235          * the validity of the request
236          */
237         status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset);
238         if (ACPI_FAILURE(status)) {
239                 return_ACPI_STATUS(status);
240         }
241
242         /*
243          * The physical address of this field datum is:
244          *
245          * 1) The base of the region, plus
246          * 2) The base offset of the field, plus
247          * 3) The current offset into the field
248          */
249         rgn_desc = obj_desc->common_field.region_obj;
250         address = rgn_desc->region.address +
251             obj_desc->common_field.base_byte_offset + field_datum_byte_offset;
252
253         if ((function & ACPI_IO_MASK) == ACPI_READ) {
254                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
255         } else {
256                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
257         }
258
259         ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
260                               " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n",
261                               acpi_ut_get_region_name(rgn_desc->region.
262                                                       space_id),
263                               rgn_desc->region.space_id,
264                               obj_desc->common_field.access_byte_width,
265                               obj_desc->common_field.base_byte_offset,
266                               field_datum_byte_offset, (void *)address));
267
268         /* Invoke the appropriate address_space/op_region handler */
269
270         status = acpi_ev_address_space_dispatch(rgn_desc, function,
271                                                 address,
272                                                 ACPI_MUL_8(obj_desc->
273                                                            common_field.
274                                                            access_byte_width),
275                                                 value);
276
277         if (ACPI_FAILURE(status)) {
278                 if (status == AE_NOT_IMPLEMENTED) {
279                         ACPI_ERROR((AE_INFO,
280                                     "Region %s(%X) not implemented",
281                                     acpi_ut_get_region_name(rgn_desc->region.
282                                                             space_id),
283                                     rgn_desc->region.space_id));
284                 } else if (status == AE_NOT_EXIST) {
285                         ACPI_ERROR((AE_INFO,
286                                     "Region %s(%X) has no handler",
287                                     acpi_ut_get_region_name(rgn_desc->region.
288                                                             space_id),
289                                     rgn_desc->region.space_id));
290                 }
291         }
292
293         return_ACPI_STATUS(status);
294 }
295
296 /*******************************************************************************
297  *
298  * FUNCTION:    acpi_ex_register_overflow
299  *
300  * PARAMETERS:  obj_desc                - Register(Field) to be written
301  *              Value                   - Value to be stored
302  *
303  * RETURN:      TRUE if value overflows the field, FALSE otherwise
304  *
305  * DESCRIPTION: Check if a value is out of range of the field being written.
306  *              Used to check if the values written to Index and Bank registers
307  *              are out of range.  Normally, the value is simply truncated
308  *              to fit the field, but this case is most likely a serious
309  *              coding error in the ASL.
310  *
311  ******************************************************************************/
312
313 static u8
314 acpi_ex_register_overflow(union acpi_operand_object *obj_desc,
315                           acpi_integer value)
316 {
317
318         if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
319                 /*
320                  * The field is large enough to hold the maximum integer, so we can
321                  * never overflow it.
322                  */
323                 return (FALSE);
324         }
325
326         if (value >= ((acpi_integer) 1 << obj_desc->common_field.bit_length)) {
327                 /*
328                  * The Value is larger than the maximum value that can fit into
329                  * the register.
330                  */
331                 return (TRUE);
332         }
333
334         /* The Value will fit into the field with no truncation */
335
336         return (FALSE);
337 }
338
339 /*******************************************************************************
340  *
341  * FUNCTION:    acpi_ex_field_datum_io
342  *
343  * PARAMETERS:  obj_desc                - Field to be read
344  *              field_datum_byte_offset - Byte offset of this datum within the
345  *                                        parent field
346  *              Value                   - Where to store value (must be 64 bits)
347  *              read_write              - Read or Write flag
348  *
349  * RETURN:      Status
350  *
351  * DESCRIPTION: Read or Write a single datum of a field.  The field_type is
352  *              demultiplexed here to handle the different types of fields
353  *              (buffer_field, region_field, index_field, bank_field)
354  *
355  ******************************************************************************/
356
357 static acpi_status
358 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
359                        u32 field_datum_byte_offset,
360                        acpi_integer * value, u32 read_write)
361 {
362         acpi_status status;
363         acpi_integer local_value;
364
365         ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
366
367         if (read_write == ACPI_READ) {
368                 if (!value) {
369                         local_value = 0;
370
371                         /* To support reads without saving return value */
372                         value = &local_value;
373                 }
374
375                 /* Clear the entire return buffer first, [Very Important!] */
376
377                 *value = 0;
378         }
379
380         /*
381          * The four types of fields are:
382          *
383          * buffer_field - Read/write from/to a Buffer
384          * region_field - Read/write from/to a Operation Region.
385          * bank_field  - Write to a Bank Register, then read/write from/to an
386          *               operation_region
387          * index_field - Write to an Index Register, then read/write from/to a
388          *               Data Register
389          */
390         switch (ACPI_GET_OBJECT_TYPE(obj_desc)) {
391         case ACPI_TYPE_BUFFER_FIELD:
392                 /*
393                  * If the buffer_field arguments have not been previously evaluated,
394                  * evaluate them now and save the results.
395                  */
396                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
397                         status = acpi_ds_get_buffer_field_arguments(obj_desc);
398                         if (ACPI_FAILURE(status)) {
399                                 return_ACPI_STATUS(status);
400                         }
401                 }
402
403                 if (read_write == ACPI_READ) {
404                         /*
405                          * Copy the data from the source buffer.
406                          * Length is the field width in bytes.
407                          */
408                         ACPI_MEMCPY(value,
409                                     (obj_desc->buffer_field.buffer_obj)->buffer.
410                                     pointer +
411                                     obj_desc->buffer_field.base_byte_offset +
412                                     field_datum_byte_offset,
413                                     obj_desc->common_field.access_byte_width);
414                 } else {
415                         /*
416                          * Copy the data to the target buffer.
417                          * Length is the field width in bytes.
418                          */
419                         ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer.
420                                     pointer +
421                                     obj_desc->buffer_field.base_byte_offset +
422                                     field_datum_byte_offset, value,
423                                     obj_desc->common_field.access_byte_width);
424                 }
425
426                 status = AE_OK;
427                 break;
428
429         case ACPI_TYPE_LOCAL_BANK_FIELD:
430
431                 /*
432                  * Ensure that the bank_value is not beyond the capacity of
433                  * the register
434                  */
435                 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
436                                               (acpi_integer) obj_desc->
437                                               bank_field.value)) {
438                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
439                 }
440
441                 /*
442                  * For bank_fields, we must write the bank_value to the bank_register
443                  * (itself a region_field) before we can access the data.
444                  */
445                 status =
446                     acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
447                                               &obj_desc->bank_field.value,
448                                               sizeof(obj_desc->bank_field.
449                                                      value));
450                 if (ACPI_FAILURE(status)) {
451                         return_ACPI_STATUS(status);
452                 }
453
454                 /*
455                  * Now that the Bank has been selected, fall through to the
456                  * region_field case and write the datum to the Operation Region
457                  */
458
459                 /*lint -fallthrough */
460
461         case ACPI_TYPE_LOCAL_REGION_FIELD:
462                 /*
463                  * For simple region_fields, we just directly access the owning
464                  * Operation Region.
465                  */
466                 status =
467                     acpi_ex_access_region(obj_desc, field_datum_byte_offset,
468                                           value, read_write);
469                 break;
470
471         case ACPI_TYPE_LOCAL_INDEX_FIELD:
472
473                 /*
474                  * Ensure that the index_value is not beyond the capacity of
475                  * the register
476                  */
477                 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
478                                               (acpi_integer) obj_desc->
479                                               index_field.value)) {
480                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
481                 }
482
483                 /* Write the index value to the index_register (itself a region_field) */
484
485                 field_datum_byte_offset += obj_desc->index_field.value;
486
487                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
488                                   "Write to Index Register: Value %8.8X\n",
489                                   field_datum_byte_offset));
490
491                 status =
492                     acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
493                                               &field_datum_byte_offset,
494                                               sizeof(field_datum_byte_offset));
495                 if (ACPI_FAILURE(status)) {
496                         return_ACPI_STATUS(status);
497                 }
498
499                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
500                                   "I/O to Data Register: ValuePtr %p\n",
501                                   value));
502
503                 if (read_write == ACPI_READ) {
504
505                         /* Read the datum from the data_register */
506
507                         status =
508                             acpi_ex_extract_from_field(obj_desc->index_field.
509                                                        data_obj, value,
510                                                        sizeof(acpi_integer));
511                 } else {
512                         /* Write the datum to the data_register */
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                             ACPI_GET_OBJECT_TYPE(obj_desc)));
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
809         ACPI_FUNCTION_TRACE(ex_insert_into_field);
810
811         /* Validate input buffer */
812
813         if (buffer_length <
814             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
815                 ACPI_ERROR((AE_INFO,
816                             "Field size %X (bits) is too large for buffer (%X)",
817                             obj_desc->common_field.bit_length, buffer_length));
818
819                 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
820         }
821
822         /*
823          * Create the bitmasks used for bit insertion.
824          * Note: This if/else is used to bypass compiler differences with the
825          * shift operator
826          */
827         if (obj_desc->common_field.access_bit_width == ACPI_INTEGER_BIT_SIZE) {
828                 width_mask = ACPI_INTEGER_MAX;
829         } else {
830                 width_mask =
831                     ACPI_MASK_BITS_ABOVE(obj_desc->common_field.
832                                          access_bit_width);
833         }
834
835         mask = width_mask &
836             ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
837
838         /* Compute the number of datums (access width data items) */
839
840         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
841                                        obj_desc->common_field.access_bit_width);
842
843         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
844                                              obj_desc->common_field.
845                                              start_field_bit_offset,
846                                              obj_desc->common_field.
847                                              access_bit_width);
848
849         /* Get initial Datum from the input buffer */
850
851         ACPI_MEMCPY(&raw_datum, buffer,
852                     ACPI_MIN(obj_desc->common_field.access_byte_width,
853                              buffer_length - buffer_offset));
854
855         merged_datum =
856             raw_datum << obj_desc->common_field.start_field_bit_offset;
857
858         /* Write the entire field */
859
860         for (i = 1; i < field_datum_count; i++) {
861
862                 /* Write merged datum to the target field */
863
864                 merged_datum &= mask;
865                 status = acpi_ex_write_with_update_rule(obj_desc, mask,
866                                                         merged_datum,
867                                                         field_offset);
868                 if (ACPI_FAILURE(status)) {
869                         return_ACPI_STATUS(status);
870                 }
871
872                 field_offset += obj_desc->common_field.access_byte_width;
873
874                 /*
875                  * Start new output datum by merging with previous input datum
876                  * if necessary.
877                  *
878                  * Note: Before the shift, check if the shift value will be larger than
879                  * the integer size. If so, there is no need to perform the operation.
880                  * This avoids the differences in behavior between different compilers
881                  * concerning shift values larger than the target data width.
882                  */
883                 if ((obj_desc->common_field.access_bit_width -
884                      obj_desc->common_field.start_field_bit_offset) <
885                     ACPI_INTEGER_BIT_SIZE) {
886                         merged_datum =
887                             raw_datum >> (obj_desc->common_field.
888                                           access_bit_width -
889                                           obj_desc->common_field.
890                                           start_field_bit_offset);
891                 } else {
892                         merged_datum = 0;
893                 }
894
895                 mask = width_mask;
896
897                 if (i == datum_count) {
898                         break;
899                 }
900
901                 /* Get the next input datum from the buffer */
902
903                 buffer_offset += obj_desc->common_field.access_byte_width;
904                 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset,
905                             ACPI_MIN(obj_desc->common_field.access_byte_width,
906                                      buffer_length - buffer_offset));
907                 merged_datum |=
908                     raw_datum << obj_desc->common_field.start_field_bit_offset;
909         }
910
911         /* Mask off any extra bits in the last datum */
912
913         buffer_tail_bits = (obj_desc->common_field.bit_length +
914                             obj_desc->common_field.start_field_bit_offset) %
915             obj_desc->common_field.access_bit_width;
916         if (buffer_tail_bits) {
917                 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
918         }
919
920         /* Write the last datum to the field */
921
922         merged_datum &= mask;
923         status = acpi_ex_write_with_update_rule(obj_desc,
924                                                 mask, merged_datum,
925                                                 field_offset);
926
927         return_ACPI_STATUS(status);
928 }