Revert "ARM: tegra: tegratab: dummy change"
[linux-2.6.git] / drivers / acpi / acpica / exfldio.c
1 /******************************************************************************
2  *
3  * Module Name: exfldio - Aml Field I/O
4  *
5  *****************************************************************************/
6
7 /*
8  * Copyright (C) 2000 - 2012, 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                        u64 *value, u32 read_write);
59
60 static u8
61 acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 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         u8 space_id;
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 0x%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         space_id = rgn_desc->region.space_id;
106
107         /* Validate the Space ID */
108
109         if (!acpi_is_valid_space_id(space_id)) {
110                 ACPI_ERROR((AE_INFO,
111                             "Invalid/unknown Address Space ID: 0x%2.2X",
112                             space_id));
113                 return_ACPI_STATUS(AE_AML_INVALID_SPACE_ID);
114         }
115
116         /*
117          * If the Region Address and Length have not been previously evaluated,
118          * evaluate them now and save the results.
119          */
120         if (!(rgn_desc->common.flags & AOPOBJ_DATA_VALID)) {
121                 status = acpi_ds_get_region_arguments(rgn_desc);
122                 if (ACPI_FAILURE(status)) {
123                         return_ACPI_STATUS(status);
124                 }
125         }
126
127         /* Exit if Address/Length have been disallowed by the host OS */
128
129         if (rgn_desc->common.flags & AOPOBJ_INVALID) {
130                 return_ACPI_STATUS(AE_AML_ILLEGAL_ADDRESS);
131         }
132
133         /*
134          * Exit now for SMBus, GSBus or IPMI address space, it has a non-linear
135          * address space and the request cannot be directly validated
136          */
137         if (space_id == ACPI_ADR_SPACE_SMBUS ||
138             space_id == ACPI_ADR_SPACE_GSBUS ||
139             space_id == ACPI_ADR_SPACE_IPMI) {
140
141                 /* SMBus or IPMI has a non-linear address space */
142
143                 return_ACPI_STATUS(AE_OK);
144         }
145 #ifdef ACPI_UNDER_DEVELOPMENT
146         /*
147          * If the Field access is any_acc, we can now compute the optimal
148          * access (because we know know the length of the parent region)
149          */
150         if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
151                 if (ACPI_FAILURE(status)) {
152                         return_ACPI_STATUS(status);
153                 }
154         }
155 #endif
156
157         /*
158          * Validate the request.  The entire request from the byte offset for a
159          * length of one field datum (access width) must fit within the region.
160          * (Region length is specified in bytes)
161          */
162         if (rgn_desc->region.length <
163             (obj_desc->common_field.base_byte_offset + field_datum_byte_offset +
164              obj_desc->common_field.access_byte_width)) {
165                 if (acpi_gbl_enable_interpreter_slack) {
166                         /*
167                          * Slack mode only:  We will go ahead and allow access to this
168                          * field if it is within the region length rounded up to the next
169                          * access width boundary. acpi_size cast for 64-bit compile.
170                          */
171                         if (ACPI_ROUND_UP(rgn_desc->region.length,
172                                           obj_desc->common_field.
173                                           access_byte_width) >=
174                             ((acpi_size) obj_desc->common_field.
175                              base_byte_offset +
176                              obj_desc->common_field.access_byte_width +
177                              field_datum_byte_offset)) {
178                                 return_ACPI_STATUS(AE_OK);
179                         }
180                 }
181
182                 if (rgn_desc->region.length <
183                     obj_desc->common_field.access_byte_width) {
184                         /*
185                          * This is the case where the access_type (acc_word, etc.) is wider
186                          * than the region itself.  For example, a region of length one
187                          * byte, and a field with Dword access specified.
188                          */
189                         ACPI_ERROR((AE_INFO,
190                                     "Field [%4.4s] access width (%u bytes) too large for region [%4.4s] (length %u)",
191                                     acpi_ut_get_node_name(obj_desc->
192                                                           common_field.node),
193                                     obj_desc->common_field.access_byte_width,
194                                     acpi_ut_get_node_name(rgn_desc->region.
195                                                           node),
196                                     rgn_desc->region.length));
197                 }
198
199                 /*
200                  * Offset rounded up to next multiple of field width
201                  * exceeds region length, indicate an error
202                  */
203                 ACPI_ERROR((AE_INFO,
204                             "Field [%4.4s] Base+Offset+Width %u+%u+%u is beyond end of region [%4.4s] (length %u)",
205                             acpi_ut_get_node_name(obj_desc->common_field.node),
206                             obj_desc->common_field.base_byte_offset,
207                             field_datum_byte_offset,
208                             obj_desc->common_field.access_byte_width,
209                             acpi_ut_get_node_name(rgn_desc->region.node),
210                             rgn_desc->region.length));
211
212                 return_ACPI_STATUS(AE_AML_REGION_LIMIT);
213         }
214
215         return_ACPI_STATUS(AE_OK);
216 }
217
218 /*******************************************************************************
219  *
220  * FUNCTION:    acpi_ex_access_region
221  *
222  * PARAMETERS:  obj_desc                - Field to be read
223  *              field_datum_byte_offset - Byte offset of this datum within the
224  *                                        parent field
225  *              Value                   - Where to store value (must at least
226  *                                        64 bits)
227  *              Function                - Read or Write flag plus other region-
228  *                                        dependent flags
229  *
230  * RETURN:      Status
231  *
232  * DESCRIPTION: Read or Write a single field datum to an Operation Region.
233  *
234  ******************************************************************************/
235
236 acpi_status
237 acpi_ex_access_region(union acpi_operand_object *obj_desc,
238                       u32 field_datum_byte_offset, u64 *value, u32 function)
239 {
240         acpi_status status;
241         union acpi_operand_object *rgn_desc;
242         u32 region_offset;
243
244         ACPI_FUNCTION_TRACE(ex_access_region);
245
246         /*
247          * Ensure that the region operands are fully evaluated and verify
248          * the validity of the request
249          */
250         status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset);
251         if (ACPI_FAILURE(status)) {
252                 return_ACPI_STATUS(status);
253         }
254
255         /*
256          * The physical address of this field datum is:
257          *
258          * 1) The base of the region, plus
259          * 2) The base offset of the field, plus
260          * 3) The current offset into the field
261          */
262         rgn_desc = obj_desc->common_field.region_obj;
263         region_offset =
264             obj_desc->common_field.base_byte_offset + field_datum_byte_offset;
265
266         if ((function & ACPI_IO_MASK) == ACPI_READ) {
267                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
268         } else {
269                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
270         }
271
272         ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
273                               " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n",
274                               acpi_ut_get_region_name(rgn_desc->region.
275                                                       space_id),
276                               rgn_desc->region.space_id,
277                               obj_desc->common_field.access_byte_width,
278                               obj_desc->common_field.base_byte_offset,
279                               field_datum_byte_offset, ACPI_CAST_PTR(void,
280                                                                      (rgn_desc->
281                                                                       region.
282                                                                       address +
283                                                                       region_offset))));
284
285         /* Invoke the appropriate address_space/op_region handler */
286
287         status = acpi_ev_address_space_dispatch(rgn_desc, obj_desc,
288                                                 function, region_offset,
289                                                 ACPI_MUL_8(obj_desc->
290                                                            common_field.
291                                                            access_byte_width),
292                                                 value);
293
294         if (ACPI_FAILURE(status)) {
295                 if (status == AE_NOT_IMPLEMENTED) {
296                         ACPI_ERROR((AE_INFO,
297                                     "Region %s (ID=%u) not implemented",
298                                     acpi_ut_get_region_name(rgn_desc->region.
299                                                             space_id),
300                                     rgn_desc->region.space_id));
301                 } else if (status == AE_NOT_EXIST) {
302                         ACPI_ERROR((AE_INFO,
303                                     "Region %s (ID=%u) has no handler",
304                                     acpi_ut_get_region_name(rgn_desc->region.
305                                                             space_id),
306                                     rgn_desc->region.space_id));
307                 }
308         }
309
310         return_ACPI_STATUS(status);
311 }
312
313 /*******************************************************************************
314  *
315  * FUNCTION:    acpi_ex_register_overflow
316  *
317  * PARAMETERS:  obj_desc                - Register(Field) to be written
318  *              Value                   - Value to be stored
319  *
320  * RETURN:      TRUE if value overflows the field, FALSE otherwise
321  *
322  * DESCRIPTION: Check if a value is out of range of the field being written.
323  *              Used to check if the values written to Index and Bank registers
324  *              are out of range.  Normally, the value is simply truncated
325  *              to fit the field, but this case is most likely a serious
326  *              coding error in the ASL.
327  *
328  ******************************************************************************/
329
330 static u8
331 acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 value)
332 {
333         ACPI_FUNCTION_NAME(ex_register_overflow);
334
335         if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
336                 /*
337                  * The field is large enough to hold the maximum integer, so we can
338                  * never overflow it.
339                  */
340                 return (FALSE);
341         }
342
343         if (value >= ((u64) 1 << obj_desc->common_field.bit_length)) {
344                 /*
345                  * The Value is larger than the maximum value that can fit into
346                  * the register.
347                  */
348                 ACPI_ERROR((AE_INFO,
349                             "Index value 0x%8.8X%8.8X overflows field width 0x%X",
350                             ACPI_FORMAT_UINT64(value),
351                             obj_desc->common_field.bit_length));
352
353                 return (TRUE);
354         }
355
356         /* The Value will fit into the field with no truncation */
357
358         return (FALSE);
359 }
360
361 /*******************************************************************************
362  *
363  * FUNCTION:    acpi_ex_field_datum_io
364  *
365  * PARAMETERS:  obj_desc                - Field to be read
366  *              field_datum_byte_offset - Byte offset of this datum within the
367  *                                        parent field
368  *              Value                   - Where to store value (must be 64 bits)
369  *              read_write              - Read or Write flag
370  *
371  * RETURN:      Status
372  *
373  * DESCRIPTION: Read or Write a single datum of a field.  The field_type is
374  *              demultiplexed here to handle the different types of fields
375  *              (buffer_field, region_field, index_field, bank_field)
376  *
377  ******************************************************************************/
378
379 static acpi_status
380 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
381                        u32 field_datum_byte_offset, u64 *value, u32 read_write)
382 {
383         acpi_status status;
384         u64 local_value;
385
386         ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
387
388         if (read_write == ACPI_READ) {
389                 if (!value) {
390                         local_value = 0;
391
392                         /* To support reads without saving return value */
393                         value = &local_value;
394                 }
395
396                 /* Clear the entire return buffer first, [Very Important!] */
397
398                 *value = 0;
399         }
400
401         /*
402          * The four types of fields are:
403          *
404          * buffer_field - Read/write from/to a Buffer
405          * region_field - Read/write from/to a Operation Region.
406          * bank_field  - Write to a Bank Register, then read/write from/to an
407          *               operation_region
408          * index_field - Write to an Index Register, then read/write from/to a
409          *               Data Register
410          */
411         switch (obj_desc->common.type) {
412         case ACPI_TYPE_BUFFER_FIELD:
413                 /*
414                  * If the buffer_field arguments have not been previously evaluated,
415                  * evaluate them now and save the results.
416                  */
417                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
418                         status = acpi_ds_get_buffer_field_arguments(obj_desc);
419                         if (ACPI_FAILURE(status)) {
420                                 return_ACPI_STATUS(status);
421                         }
422                 }
423
424                 if (read_write == ACPI_READ) {
425                         /*
426                          * Copy the data from the source buffer.
427                          * Length is the field width in bytes.
428                          */
429                         ACPI_MEMCPY(value,
430                                     (obj_desc->buffer_field.buffer_obj)->buffer.
431                                     pointer +
432                                     obj_desc->buffer_field.base_byte_offset +
433                                     field_datum_byte_offset,
434                                     obj_desc->common_field.access_byte_width);
435                 } else {
436                         /*
437                          * Copy the data to the target buffer.
438                          * Length is the field width in bytes.
439                          */
440                         ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer.
441                                     pointer +
442                                     obj_desc->buffer_field.base_byte_offset +
443                                     field_datum_byte_offset, value,
444                                     obj_desc->common_field.access_byte_width);
445                 }
446
447                 status = AE_OK;
448                 break;
449
450         case ACPI_TYPE_LOCAL_BANK_FIELD:
451
452                 /*
453                  * Ensure that the bank_value is not beyond the capacity of
454                  * the register
455                  */
456                 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
457                                               (u64) obj_desc->bank_field.
458                                               value)) {
459                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
460                 }
461
462                 /*
463                  * For bank_fields, we must write the bank_value to the bank_register
464                  * (itself a region_field) before we can access the data.
465                  */
466                 status =
467                     acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
468                                               &obj_desc->bank_field.value,
469                                               sizeof(obj_desc->bank_field.
470                                                      value));
471                 if (ACPI_FAILURE(status)) {
472                         return_ACPI_STATUS(status);
473                 }
474
475                 /*
476                  * Now that the Bank has been selected, fall through to the
477                  * region_field case and write the datum to the Operation Region
478                  */
479
480                 /*lint -fallthrough */
481
482         case ACPI_TYPE_LOCAL_REGION_FIELD:
483                 /*
484                  * For simple region_fields, we just directly access the owning
485                  * Operation Region.
486                  */
487                 status =
488                     acpi_ex_access_region(obj_desc, field_datum_byte_offset,
489                                           value, read_write);
490                 break;
491
492         case ACPI_TYPE_LOCAL_INDEX_FIELD:
493
494                 /*
495                  * Ensure that the index_value is not beyond the capacity of
496                  * the register
497                  */
498                 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
499                                               (u64) obj_desc->index_field.
500                                               value)) {
501                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
502                 }
503
504                 /* Write the index value to the index_register (itself a region_field) */
505
506                 field_datum_byte_offset += obj_desc->index_field.value;
507
508                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
509                                   "Write to Index Register: Value %8.8X\n",
510                                   field_datum_byte_offset));
511
512                 status =
513                     acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
514                                               &field_datum_byte_offset,
515                                               sizeof(field_datum_byte_offset));
516                 if (ACPI_FAILURE(status)) {
517                         return_ACPI_STATUS(status);
518                 }
519
520                 if (read_write == ACPI_READ) {
521
522                         /* Read the datum from the data_register */
523
524                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
525                                           "Read from Data Register\n"));
526
527                         status =
528                             acpi_ex_extract_from_field(obj_desc->index_field.
529                                                        data_obj, value,
530                                                        sizeof(u64));
531                 } else {
532                         /* Write the datum to the data_register */
533
534                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
535                                           "Write to Data Register: Value %8.8X%8.8X\n",
536                                           ACPI_FORMAT_UINT64(*value)));
537
538                         status =
539                             acpi_ex_insert_into_field(obj_desc->index_field.
540                                                       data_obj, value,
541                                                       sizeof(u64));
542                 }
543                 break;
544
545         default:
546
547                 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %u",
548                             obj_desc->common.type));
549                 status = AE_AML_INTERNAL;
550                 break;
551         }
552
553         if (ACPI_SUCCESS(status)) {
554                 if (read_write == ACPI_READ) {
555                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
556                                           "Value Read %8.8X%8.8X, Width %u\n",
557                                           ACPI_FORMAT_UINT64(*value),
558                                           obj_desc->common_field.
559                                           access_byte_width));
560                 } else {
561                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
562                                           "Value Written %8.8X%8.8X, Width %u\n",
563                                           ACPI_FORMAT_UINT64(*value),
564                                           obj_desc->common_field.
565                                           access_byte_width));
566                 }
567         }
568
569         return_ACPI_STATUS(status);
570 }
571
572 /*******************************************************************************
573  *
574  * FUNCTION:    acpi_ex_write_with_update_rule
575  *
576  * PARAMETERS:  obj_desc                - Field to be written
577  *              Mask                    - bitmask within field datum
578  *              field_value             - Value to write
579  *              field_datum_byte_offset - Offset of datum within field
580  *
581  * RETURN:      Status
582  *
583  * DESCRIPTION: Apply the field update rule to a field write
584  *
585  ******************************************************************************/
586
587 acpi_status
588 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc,
589                                u64 mask,
590                                u64 field_value, u32 field_datum_byte_offset)
591 {
592         acpi_status status = AE_OK;
593         u64 merged_value;
594         u64 current_value;
595
596         ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask);
597
598         /* Start with the new bits  */
599
600         merged_value = field_value;
601
602         /* If the mask is all ones, we don't need to worry about the update rule */
603
604         if (mask != ACPI_UINT64_MAX) {
605
606                 /* Decode the update rule */
607
608                 switch (obj_desc->common_field.
609                         field_flags & AML_FIELD_UPDATE_RULE_MASK) {
610                 case AML_FIELD_UPDATE_PRESERVE:
611                         /*
612                          * Check if update rule needs to be applied (not if mask is all
613                          * ones)  The left shift drops the bits we want to ignore.
614                          */
615                         if ((~mask << (ACPI_MUL_8(sizeof(mask)) -
616                                        ACPI_MUL_8(obj_desc->common_field.
617                                                   access_byte_width))) != 0) {
618                                 /*
619                                  * Read the current contents of the byte/word/dword containing
620                                  * the field, and merge with the new field value.
621                                  */
622                                 status =
623                                     acpi_ex_field_datum_io(obj_desc,
624                                                            field_datum_byte_offset,
625                                                            &current_value,
626                                                            ACPI_READ);
627                                 if (ACPI_FAILURE(status)) {
628                                         return_ACPI_STATUS(status);
629                                 }
630
631                                 merged_value |= (current_value & ~mask);
632                         }
633                         break;
634
635                 case AML_FIELD_UPDATE_WRITE_AS_ONES:
636
637                         /* Set positions outside the field to all ones */
638
639                         merged_value |= ~mask;
640                         break;
641
642                 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
643
644                         /* Set positions outside the field to all zeros */
645
646                         merged_value &= mask;
647                         break;
648
649                 default:
650
651                         ACPI_ERROR((AE_INFO,
652                                     "Unknown UpdateRule value: 0x%X",
653                                     (obj_desc->common_field.
654                                      field_flags &
655                                      AML_FIELD_UPDATE_RULE_MASK)));
656                         return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
657                 }
658         }
659
660         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
661                           "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
662                           ACPI_FORMAT_UINT64(mask),
663                           field_datum_byte_offset,
664                           obj_desc->common_field.access_byte_width,
665                           ACPI_FORMAT_UINT64(field_value),
666                           ACPI_FORMAT_UINT64(merged_value)));
667
668         /* Write the merged value */
669
670         status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset,
671                                         &merged_value, ACPI_WRITE);
672
673         return_ACPI_STATUS(status);
674 }
675
676 /*******************************************************************************
677  *
678  * FUNCTION:    acpi_ex_extract_from_field
679  *
680  * PARAMETERS:  obj_desc            - Field to be read
681  *              Buffer              - Where to store the field data
682  *              buffer_length       - Length of Buffer
683  *
684  * RETURN:      Status
685  *
686  * DESCRIPTION: Retrieve the current value of the given field
687  *
688  ******************************************************************************/
689
690 acpi_status
691 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
692                            void *buffer, u32 buffer_length)
693 {
694         acpi_status status;
695         u64 raw_datum;
696         u64 merged_datum;
697         u32 field_offset = 0;
698         u32 buffer_offset = 0;
699         u32 buffer_tail_bits;
700         u32 datum_count;
701         u32 field_datum_count;
702         u32 access_bit_width;
703         u32 i;
704
705         ACPI_FUNCTION_TRACE(ex_extract_from_field);
706
707         /* Validate target buffer and clear it */
708
709         if (buffer_length <
710             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
711                 ACPI_ERROR((AE_INFO,
712                             "Field size %u (bits) is too large for buffer (%u)",
713                             obj_desc->common_field.bit_length, buffer_length));
714
715                 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
716         }
717
718         ACPI_MEMSET(buffer, 0, buffer_length);
719         access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
720
721         /* Handle the simple case here */
722
723         if ((obj_desc->common_field.start_field_bit_offset == 0) &&
724             (obj_desc->common_field.bit_length == access_bit_width)) {
725                 if (buffer_length >= sizeof(u64)) {
726                         status =
727                             acpi_ex_field_datum_io(obj_desc, 0, buffer,
728                                                    ACPI_READ);
729                 } else {
730                         /* Use raw_datum (u64) to handle buffers < 64 bits */
731
732                         status =
733                             acpi_ex_field_datum_io(obj_desc, 0, &raw_datum,
734                                                    ACPI_READ);
735                         ACPI_MEMCPY(buffer, &raw_datum, buffer_length);
736                 }
737
738                 return_ACPI_STATUS(status);
739         }
740
741 /* TBD: Move to common setup code */
742
743         /* Field algorithm is limited to sizeof(u64), truncate if needed */
744
745         if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
746                 obj_desc->common_field.access_byte_width = sizeof(u64);
747                 access_bit_width = sizeof(u64) * 8;
748         }
749
750         /* Compute the number of datums (access width data items) */
751
752         datum_count =
753             ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
754                              access_bit_width);
755
756         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
757                                              obj_desc->common_field.
758                                              start_field_bit_offset,
759                                              access_bit_width);
760
761         /* Priming read from the field */
762
763         status =
764             acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
765                                    ACPI_READ);
766         if (ACPI_FAILURE(status)) {
767                 return_ACPI_STATUS(status);
768         }
769         merged_datum =
770             raw_datum >> obj_desc->common_field.start_field_bit_offset;
771
772         /* Read the rest of the field */
773
774         for (i = 1; i < field_datum_count; i++) {
775
776                 /* Get next input datum from the field */
777
778                 field_offset += obj_desc->common_field.access_byte_width;
779                 status = acpi_ex_field_datum_io(obj_desc, field_offset,
780                                                 &raw_datum, ACPI_READ);
781                 if (ACPI_FAILURE(status)) {
782                         return_ACPI_STATUS(status);
783                 }
784
785                 /*
786                  * Merge with previous datum if necessary.
787                  *
788                  * Note: Before the shift, check if the shift value will be larger than
789                  * the integer size. If so, there is no need to perform the operation.
790                  * This avoids the differences in behavior between different compilers
791                  * concerning shift values larger than the target data width.
792                  */
793                 if (access_bit_width -
794                     obj_desc->common_field.start_field_bit_offset <
795                     ACPI_INTEGER_BIT_SIZE) {
796                         merged_datum |=
797                             raw_datum << (access_bit_width -
798                                           obj_desc->common_field.
799                                           start_field_bit_offset);
800                 }
801
802                 if (i == datum_count) {
803                         break;
804                 }
805
806                 /* Write merged datum to target buffer */
807
808                 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
809                             ACPI_MIN(obj_desc->common_field.access_byte_width,
810                                      buffer_length - buffer_offset));
811
812                 buffer_offset += obj_desc->common_field.access_byte_width;
813                 merged_datum =
814                     raw_datum >> obj_desc->common_field.start_field_bit_offset;
815         }
816
817         /* Mask off any extra bits in the last datum */
818
819         buffer_tail_bits = obj_desc->common_field.bit_length % access_bit_width;
820         if (buffer_tail_bits) {
821                 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
822         }
823
824         /* Write the last datum to the buffer */
825
826         ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
827                     ACPI_MIN(obj_desc->common_field.access_byte_width,
828                              buffer_length - buffer_offset));
829
830         return_ACPI_STATUS(AE_OK);
831 }
832
833 /*******************************************************************************
834  *
835  * FUNCTION:    acpi_ex_insert_into_field
836  *
837  * PARAMETERS:  obj_desc            - Field to be written
838  *              Buffer              - Data to be written
839  *              buffer_length       - Length of Buffer
840  *
841  * RETURN:      Status
842  *
843  * DESCRIPTION: Store the Buffer contents into the given field
844  *
845  ******************************************************************************/
846
847 acpi_status
848 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
849                           void *buffer, u32 buffer_length)
850 {
851         void *new_buffer;
852         acpi_status status;
853         u64 mask;
854         u64 width_mask;
855         u64 merged_datum;
856         u64 raw_datum = 0;
857         u32 field_offset = 0;
858         u32 buffer_offset = 0;
859         u32 buffer_tail_bits;
860         u32 datum_count;
861         u32 field_datum_count;
862         u32 access_bit_width;
863         u32 required_length;
864         u32 i;
865
866         ACPI_FUNCTION_TRACE(ex_insert_into_field);
867
868         /* Validate input buffer */
869
870         new_buffer = NULL;
871         required_length =
872             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
873         /*
874          * We must have a buffer that is at least as long as the field
875          * we are writing to.  This is because individual fields are
876          * indivisible and partial writes are not supported -- as per
877          * the ACPI specification.
878          */
879         if (buffer_length < required_length) {
880
881                 /* We need to create a new buffer */
882
883                 new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
884                 if (!new_buffer) {
885                         return_ACPI_STATUS(AE_NO_MEMORY);
886                 }
887
888                 /*
889                  * Copy the original data to the new buffer, starting
890                  * at Byte zero.  All unused (upper) bytes of the
891                  * buffer will be 0.
892                  */
893                 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length);
894                 buffer = new_buffer;
895                 buffer_length = required_length;
896         }
897
898 /* TBD: Move to common setup code */
899
900         /* Algo is limited to sizeof(u64), so cut the access_byte_width */
901         if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
902                 obj_desc->common_field.access_byte_width = sizeof(u64);
903         }
904
905         access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
906
907         /*
908          * Create the bitmasks used for bit insertion.
909          * Note: This if/else is used to bypass compiler differences with the
910          * shift operator
911          */
912         if (access_bit_width == ACPI_INTEGER_BIT_SIZE) {
913                 width_mask = ACPI_UINT64_MAX;
914         } else {
915                 width_mask = ACPI_MASK_BITS_ABOVE(access_bit_width);
916         }
917
918         mask = width_mask &
919             ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
920
921         /* Compute the number of datums (access width data items) */
922
923         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
924                                        access_bit_width);
925
926         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
927                                              obj_desc->common_field.
928                                              start_field_bit_offset,
929                                              access_bit_width);
930
931         /* Get initial Datum from the input buffer */
932
933         ACPI_MEMCPY(&raw_datum, buffer,
934                     ACPI_MIN(obj_desc->common_field.access_byte_width,
935                              buffer_length - buffer_offset));
936
937         merged_datum =
938             raw_datum << obj_desc->common_field.start_field_bit_offset;
939
940         /* Write the entire field */
941
942         for (i = 1; i < field_datum_count; i++) {
943
944                 /* Write merged datum to the target field */
945
946                 merged_datum &= mask;
947                 status = acpi_ex_write_with_update_rule(obj_desc, mask,
948                                                         merged_datum,
949                                                         field_offset);
950                 if (ACPI_FAILURE(status)) {
951                         goto exit;
952                 }
953
954                 field_offset += obj_desc->common_field.access_byte_width;
955
956                 /*
957                  * Start new output datum by merging with previous input datum
958                  * if necessary.
959                  *
960                  * Note: Before the shift, check if the shift value will be larger than
961                  * the integer size. If so, there is no need to perform the operation.
962                  * This avoids the differences in behavior between different compilers
963                  * concerning shift values larger than the target data width.
964                  */
965                 if ((access_bit_width -
966                      obj_desc->common_field.start_field_bit_offset) <
967                     ACPI_INTEGER_BIT_SIZE) {
968                         merged_datum =
969                             raw_datum >> (access_bit_width -
970                                           obj_desc->common_field.
971                                           start_field_bit_offset);
972                 } else {
973                         merged_datum = 0;
974                 }
975
976                 mask = width_mask;
977
978                 if (i == datum_count) {
979                         break;
980                 }
981
982                 /* Get the next input datum from the buffer */
983
984                 buffer_offset += obj_desc->common_field.access_byte_width;
985                 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset,
986                             ACPI_MIN(obj_desc->common_field.access_byte_width,
987                                      buffer_length - buffer_offset));
988
989                 merged_datum |=
990                     raw_datum << obj_desc->common_field.start_field_bit_offset;
991         }
992
993         /* Mask off any extra bits in the last datum */
994
995         buffer_tail_bits = (obj_desc->common_field.bit_length +
996                             obj_desc->common_field.start_field_bit_offset) %
997             access_bit_width;
998         if (buffer_tail_bits) {
999                 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
1000         }
1001
1002         /* Write the last datum to the field */
1003
1004         merged_datum &= mask;
1005         status = acpi_ex_write_with_update_rule(obj_desc,
1006                                                 mask, merged_datum,
1007                                                 field_offset);
1008
1009       exit:
1010         /* Free temporary buffer if we used one */
1011
1012         if (new_buffer) {
1013                 ACPI_FREE(new_buffer);
1014         }
1015         return_ACPI_STATUS(status);
1016 }