ACPICA: Update all ACPICA copyrights and signons to 2010
[linux-3.10.git] / drivers / acpi / acpica / exfldio.c
1 /******************************************************************************
2  *
3  * Module Name: exfldio - Aml Field I/O
4  *
5  *****************************************************************************/
6
7 /*
8  * Copyright (C) 2000 - 2010, 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         /* Exit if Address/Length have been disallowed by the host OS */
117
118         if (rgn_desc->common.flags & AOPOBJ_INVALID) {
119                 return_ACPI_STATUS(AE_AML_ILLEGAL_ADDRESS);
120         }
121
122         /*
123          * Exit now for SMBus or IPMI address space, it has a non-linear address space
124          * and the request cannot be directly validated
125          */
126         if (rgn_desc->region.space_id == ACPI_ADR_SPACE_SMBUS ||
127             rgn_desc->region.space_id == ACPI_ADR_SPACE_IPMI) {
128
129                 /* SMBus or IPMI has a non-linear address space */
130
131                 return_ACPI_STATUS(AE_OK);
132         }
133 #ifdef ACPI_UNDER_DEVELOPMENT
134         /*
135          * If the Field access is any_acc, we can now compute the optimal
136          * access (because we know know the length of the parent region)
137          */
138         if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
139                 if (ACPI_FAILURE(status)) {
140                         return_ACPI_STATUS(status);
141                 }
142         }
143 #endif
144
145         /*
146          * Validate the request.  The entire request from the byte offset for a
147          * length of one field datum (access width) must fit within the region.
148          * (Region length is specified in bytes)
149          */
150         if (rgn_desc->region.length <
151             (obj_desc->common_field.base_byte_offset +
152              field_datum_byte_offset +
153              obj_desc->common_field.access_byte_width)) {
154                 if (acpi_gbl_enable_interpreter_slack) {
155                         /*
156                          * Slack mode only:  We will go ahead and allow access to this
157                          * field if it is within the region length rounded up to the next
158                          * access width boundary. acpi_size cast for 64-bit compile.
159                          */
160                         if (ACPI_ROUND_UP(rgn_desc->region.length,
161                                           obj_desc->common_field.
162                                           access_byte_width) >=
163                             ((acpi_size) obj_desc->common_field.
164                              base_byte_offset +
165                              obj_desc->common_field.access_byte_width +
166                              field_datum_byte_offset)) {
167                                 return_ACPI_STATUS(AE_OK);
168                         }
169                 }
170
171                 if (rgn_desc->region.length <
172                     obj_desc->common_field.access_byte_width) {
173                         /*
174                          * This is the case where the access_type (acc_word, etc.) is wider
175                          * than the region itself.  For example, a region of length one
176                          * byte, and a field with Dword access specified.
177                          */
178                         ACPI_ERROR((AE_INFO,
179                                     "Field [%4.4s] access width (%d bytes) too large for region [%4.4s] (length %X)",
180                                     acpi_ut_get_node_name(obj_desc->
181                                                           common_field.node),
182                                     obj_desc->common_field.access_byte_width,
183                                     acpi_ut_get_node_name(rgn_desc->region.
184                                                           node),
185                                     rgn_desc->region.length));
186                 }
187
188                 /*
189                  * Offset rounded up to next multiple of field width
190                  * exceeds region length, indicate an error
191                  */
192                 ACPI_ERROR((AE_INFO,
193                             "Field [%4.4s] Base+Offset+Width %X+%X+%X is beyond end of region [%4.4s] (length %X)",
194                             acpi_ut_get_node_name(obj_desc->common_field.node),
195                             obj_desc->common_field.base_byte_offset,
196                             field_datum_byte_offset,
197                             obj_desc->common_field.access_byte_width,
198                             acpi_ut_get_node_name(rgn_desc->region.node),
199                             rgn_desc->region.length));
200
201                 return_ACPI_STATUS(AE_AML_REGION_LIMIT);
202         }
203
204         return_ACPI_STATUS(AE_OK);
205 }
206
207 /*******************************************************************************
208  *
209  * FUNCTION:    acpi_ex_access_region
210  *
211  * PARAMETERS:  obj_desc                - Field to be read
212  *              field_datum_byte_offset - Byte offset of this datum within the
213  *                                        parent field
214  *              Value                   - Where to store value (must at least
215  *                                        the size of acpi_integer)
216  *              Function                - Read or Write flag plus other region-
217  *                                        dependent flags
218  *
219  * RETURN:      Status
220  *
221  * DESCRIPTION: Read or Write a single field datum to an Operation Region.
222  *
223  ******************************************************************************/
224
225 acpi_status
226 acpi_ex_access_region(union acpi_operand_object *obj_desc,
227                       u32 field_datum_byte_offset,
228                       acpi_integer * value, u32 function)
229 {
230         acpi_status status;
231         union acpi_operand_object *rgn_desc;
232         u32 region_offset;
233
234         ACPI_FUNCTION_TRACE(ex_access_region);
235
236         /*
237          * Ensure that the region operands are fully evaluated and verify
238          * the validity of the request
239          */
240         status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset);
241         if (ACPI_FAILURE(status)) {
242                 return_ACPI_STATUS(status);
243         }
244
245         /*
246          * The physical address of this field datum is:
247          *
248          * 1) The base of the region, plus
249          * 2) The base offset of the field, plus
250          * 3) The current offset into the field
251          */
252         rgn_desc = obj_desc->common_field.region_obj;
253         region_offset =
254             obj_desc->common_field.base_byte_offset + field_datum_byte_offset;
255
256         if ((function & ACPI_IO_MASK) == ACPI_READ) {
257                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
258         } else {
259                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
260         }
261
262         ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
263                               " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n",
264                               acpi_ut_get_region_name(rgn_desc->region.
265                                                       space_id),
266                               rgn_desc->region.space_id,
267                               obj_desc->common_field.access_byte_width,
268                               obj_desc->common_field.base_byte_offset,
269                               field_datum_byte_offset, ACPI_CAST_PTR(void,
270                                                                      (rgn_desc->
271                                                                       region.
272                                                                       address +
273                                                                       region_offset))));
274
275         /* Invoke the appropriate address_space/op_region handler */
276
277         status =
278             acpi_ev_address_space_dispatch(rgn_desc, function, region_offset,
279                                            ACPI_MUL_8(obj_desc->common_field.
280                                                       access_byte_width),
281                                            value);
282
283         if (ACPI_FAILURE(status)) {
284                 if (status == AE_NOT_IMPLEMENTED) {
285                         ACPI_ERROR((AE_INFO,
286                                     "Region %s(%X) not implemented",
287                                     acpi_ut_get_region_name(rgn_desc->region.
288                                                             space_id),
289                                     rgn_desc->region.space_id));
290                 } else if (status == AE_NOT_EXIST) {
291                         ACPI_ERROR((AE_INFO,
292                                     "Region %s(%X) has no handler",
293                                     acpi_ut_get_region_name(rgn_desc->region.
294                                                             space_id),
295                                     rgn_desc->region.space_id));
296                 }
297         }
298
299         return_ACPI_STATUS(status);
300 }
301
302 /*******************************************************************************
303  *
304  * FUNCTION:    acpi_ex_register_overflow
305  *
306  * PARAMETERS:  obj_desc                - Register(Field) to be written
307  *              Value                   - Value to be stored
308  *
309  * RETURN:      TRUE if value overflows the field, FALSE otherwise
310  *
311  * DESCRIPTION: Check if a value is out of range of the field being written.
312  *              Used to check if the values written to Index and Bank registers
313  *              are out of range.  Normally, the value is simply truncated
314  *              to fit the field, but this case is most likely a serious
315  *              coding error in the ASL.
316  *
317  ******************************************************************************/
318
319 static u8
320 acpi_ex_register_overflow(union acpi_operand_object *obj_desc,
321                           acpi_integer value)
322 {
323
324         if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
325                 /*
326                  * The field is large enough to hold the maximum integer, so we can
327                  * never overflow it.
328                  */
329                 return (FALSE);
330         }
331
332         if (value >= ((acpi_integer) 1 << obj_desc->common_field.bit_length)) {
333                 /*
334                  * The Value is larger than the maximum value that can fit into
335                  * the register.
336                  */
337                 return (TRUE);
338         }
339
340         /* The Value will fit into the field with no truncation */
341
342         return (FALSE);
343 }
344
345 /*******************************************************************************
346  *
347  * FUNCTION:    acpi_ex_field_datum_io
348  *
349  * PARAMETERS:  obj_desc                - Field to be read
350  *              field_datum_byte_offset - Byte offset of this datum within the
351  *                                        parent field
352  *              Value                   - Where to store value (must be 64 bits)
353  *              read_write              - Read or Write flag
354  *
355  * RETURN:      Status
356  *
357  * DESCRIPTION: Read or Write a single datum of a field.  The field_type is
358  *              demultiplexed here to handle the different types of fields
359  *              (buffer_field, region_field, index_field, bank_field)
360  *
361  ******************************************************************************/
362
363 static acpi_status
364 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
365                        u32 field_datum_byte_offset,
366                        acpi_integer * value, u32 read_write)
367 {
368         acpi_status status;
369         acpi_integer local_value;
370
371         ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
372
373         if (read_write == ACPI_READ) {
374                 if (!value) {
375                         local_value = 0;
376
377                         /* To support reads without saving return value */
378                         value = &local_value;
379                 }
380
381                 /* Clear the entire return buffer first, [Very Important!] */
382
383                 *value = 0;
384         }
385
386         /*
387          * The four types of fields are:
388          *
389          * buffer_field - Read/write from/to a Buffer
390          * region_field - Read/write from/to a Operation Region.
391          * bank_field  - Write to a Bank Register, then read/write from/to an
392          *               operation_region
393          * index_field - Write to an Index Register, then read/write from/to a
394          *               Data Register
395          */
396         switch (obj_desc->common.type) {
397         case ACPI_TYPE_BUFFER_FIELD:
398                 /*
399                  * If the buffer_field arguments have not been previously evaluated,
400                  * evaluate them now and save the results.
401                  */
402                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
403                         status = acpi_ds_get_buffer_field_arguments(obj_desc);
404                         if (ACPI_FAILURE(status)) {
405                                 return_ACPI_STATUS(status);
406                         }
407                 }
408
409                 if (read_write == ACPI_READ) {
410                         /*
411                          * Copy the data from the source buffer.
412                          * Length is the field width in bytes.
413                          */
414                         ACPI_MEMCPY(value,
415                                     (obj_desc->buffer_field.buffer_obj)->buffer.
416                                     pointer +
417                                     obj_desc->buffer_field.base_byte_offset +
418                                     field_datum_byte_offset,
419                                     obj_desc->common_field.access_byte_width);
420                 } else {
421                         /*
422                          * Copy the data to the target buffer.
423                          * Length is the field width in bytes.
424                          */
425                         ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer.
426                                     pointer +
427                                     obj_desc->buffer_field.base_byte_offset +
428                                     field_datum_byte_offset, value,
429                                     obj_desc->common_field.access_byte_width);
430                 }
431
432                 status = AE_OK;
433                 break;
434
435         case ACPI_TYPE_LOCAL_BANK_FIELD:
436
437                 /*
438                  * Ensure that the bank_value is not beyond the capacity of
439                  * the register
440                  */
441                 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
442                                               (acpi_integer) obj_desc->
443                                               bank_field.value)) {
444                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
445                 }
446
447                 /*
448                  * For bank_fields, we must write the bank_value to the bank_register
449                  * (itself a region_field) before we can access the data.
450                  */
451                 status =
452                     acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
453                                               &obj_desc->bank_field.value,
454                                               sizeof(obj_desc->bank_field.
455                                                      value));
456                 if (ACPI_FAILURE(status)) {
457                         return_ACPI_STATUS(status);
458                 }
459
460                 /*
461                  * Now that the Bank has been selected, fall through to the
462                  * region_field case and write the datum to the Operation Region
463                  */
464
465                 /*lint -fallthrough */
466
467         case ACPI_TYPE_LOCAL_REGION_FIELD:
468                 /*
469                  * For simple region_fields, we just directly access the owning
470                  * Operation Region.
471                  */
472                 status =
473                     acpi_ex_access_region(obj_desc, field_datum_byte_offset,
474                                           value, read_write);
475                 break;
476
477         case ACPI_TYPE_LOCAL_INDEX_FIELD:
478
479                 /*
480                  * Ensure that the index_value is not beyond the capacity of
481                  * the register
482                  */
483                 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
484                                               (acpi_integer) obj_desc->
485                                               index_field.value)) {
486                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
487                 }
488
489                 /* Write the index value to the index_register (itself a region_field) */
490
491                 field_datum_byte_offset += obj_desc->index_field.value;
492
493                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
494                                   "Write to Index Register: Value %8.8X\n",
495                                   field_datum_byte_offset));
496
497                 status =
498                     acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
499                                               &field_datum_byte_offset,
500                                               sizeof(field_datum_byte_offset));
501                 if (ACPI_FAILURE(status)) {
502                         return_ACPI_STATUS(status);
503                 }
504
505                 if (read_write == ACPI_READ) {
506
507                         /* Read the datum from the data_register */
508
509                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
510                                           "Read from Data Register\n"));
511
512                         status =
513                             acpi_ex_extract_from_field(obj_desc->index_field.
514                                                        data_obj, value,
515                                                        sizeof(acpi_integer));
516                 } else {
517                         /* Write the datum to the data_register */
518
519                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
520                                           "Write to Data Register: Value %8.8X%8.8X\n",
521                                           ACPI_FORMAT_UINT64(*value)));
522
523                         status =
524                             acpi_ex_insert_into_field(obj_desc->index_field.
525                                                       data_obj, value,
526                                                       sizeof(acpi_integer));
527                 }
528                 break;
529
530         default:
531
532                 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %X",
533                             obj_desc->common.type));
534                 status = AE_AML_INTERNAL;
535                 break;
536         }
537
538         if (ACPI_SUCCESS(status)) {
539                 if (read_write == ACPI_READ) {
540                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
541                                           "Value Read %8.8X%8.8X, Width %d\n",
542                                           ACPI_FORMAT_UINT64(*value),
543                                           obj_desc->common_field.
544                                           access_byte_width));
545                 } else {
546                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
547                                           "Value Written %8.8X%8.8X, Width %d\n",
548                                           ACPI_FORMAT_UINT64(*value),
549                                           obj_desc->common_field.
550                                           access_byte_width));
551                 }
552         }
553
554         return_ACPI_STATUS(status);
555 }
556
557 /*******************************************************************************
558  *
559  * FUNCTION:    acpi_ex_write_with_update_rule
560  *
561  * PARAMETERS:  obj_desc                - Field to be written
562  *              Mask                    - bitmask within field datum
563  *              field_value             - Value to write
564  *              field_datum_byte_offset - Offset of datum within field
565  *
566  * RETURN:      Status
567  *
568  * DESCRIPTION: Apply the field update rule to a field write
569  *
570  ******************************************************************************/
571
572 acpi_status
573 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc,
574                                acpi_integer mask,
575                                acpi_integer field_value,
576                                u32 field_datum_byte_offset)
577 {
578         acpi_status status = AE_OK;
579         acpi_integer merged_value;
580         acpi_integer current_value;
581
582         ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask);
583
584         /* Start with the new bits  */
585
586         merged_value = field_value;
587
588         /* If the mask is all ones, we don't need to worry about the update rule */
589
590         if (mask != ACPI_INTEGER_MAX) {
591
592                 /* Decode the update rule */
593
594                 switch (obj_desc->common_field.
595                         field_flags & AML_FIELD_UPDATE_RULE_MASK) {
596                 case AML_FIELD_UPDATE_PRESERVE:
597                         /*
598                          * Check if update rule needs to be applied (not if mask is all
599                          * ones)  The left shift drops the bits we want to ignore.
600                          */
601                         if ((~mask << (ACPI_MUL_8(sizeof(mask)) -
602                                        ACPI_MUL_8(obj_desc->common_field.
603                                                   access_byte_width))) != 0) {
604                                 /*
605                                  * Read the current contents of the byte/word/dword containing
606                                  * the field, and merge with the new field value.
607                                  */
608                                 status =
609                                     acpi_ex_field_datum_io(obj_desc,
610                                                            field_datum_byte_offset,
611                                                            &current_value,
612                                                            ACPI_READ);
613                                 if (ACPI_FAILURE(status)) {
614                                         return_ACPI_STATUS(status);
615                                 }
616
617                                 merged_value |= (current_value & ~mask);
618                         }
619                         break;
620
621                 case AML_FIELD_UPDATE_WRITE_AS_ONES:
622
623                         /* Set positions outside the field to all ones */
624
625                         merged_value |= ~mask;
626                         break;
627
628                 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
629
630                         /* Set positions outside the field to all zeros */
631
632                         merged_value &= mask;
633                         break;
634
635                 default:
636
637                         ACPI_ERROR((AE_INFO,
638                                     "Unknown UpdateRule value: %X",
639                                     (obj_desc->common_field.
640                                      field_flags &
641                                      AML_FIELD_UPDATE_RULE_MASK)));
642                         return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
643                 }
644         }
645
646         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
647                           "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
648                           ACPI_FORMAT_UINT64(mask),
649                           field_datum_byte_offset,
650                           obj_desc->common_field.access_byte_width,
651                           ACPI_FORMAT_UINT64(field_value),
652                           ACPI_FORMAT_UINT64(merged_value)));
653
654         /* Write the merged value */
655
656         status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset,
657                                         &merged_value, ACPI_WRITE);
658
659         return_ACPI_STATUS(status);
660 }
661
662 /*******************************************************************************
663  *
664  * FUNCTION:    acpi_ex_extract_from_field
665  *
666  * PARAMETERS:  obj_desc            - Field to be read
667  *              Buffer              - Where to store the field data
668  *              buffer_length       - Length of Buffer
669  *
670  * RETURN:      Status
671  *
672  * DESCRIPTION: Retrieve the current value of the given field
673  *
674  ******************************************************************************/
675
676 acpi_status
677 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
678                            void *buffer, u32 buffer_length)
679 {
680         acpi_status status;
681         acpi_integer raw_datum;
682         acpi_integer merged_datum;
683         u32 field_offset = 0;
684         u32 buffer_offset = 0;
685         u32 buffer_tail_bits;
686         u32 datum_count;
687         u32 field_datum_count;
688         u32 i;
689
690         ACPI_FUNCTION_TRACE(ex_extract_from_field);
691
692         /* Validate target buffer and clear it */
693
694         if (buffer_length <
695             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
696                 ACPI_ERROR((AE_INFO,
697                             "Field size %X (bits) is too large for buffer (%X)",
698                             obj_desc->common_field.bit_length, buffer_length));
699
700                 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
701         }
702         ACPI_MEMSET(buffer, 0, buffer_length);
703
704         /* Compute the number of datums (access width data items) */
705
706         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
707                                        obj_desc->common_field.access_bit_width);
708         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
709                                              obj_desc->common_field.
710                                              start_field_bit_offset,
711                                              obj_desc->common_field.
712                                              access_bit_width);
713
714         /* Priming read from the field */
715
716         status =
717             acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
718                                    ACPI_READ);
719         if (ACPI_FAILURE(status)) {
720                 return_ACPI_STATUS(status);
721         }
722         merged_datum =
723             raw_datum >> obj_desc->common_field.start_field_bit_offset;
724
725         /* Read the rest of the field */
726
727         for (i = 1; i < field_datum_count; i++) {
728
729                 /* Get next input datum from the field */
730
731                 field_offset += obj_desc->common_field.access_byte_width;
732                 status = acpi_ex_field_datum_io(obj_desc, field_offset,
733                                                 &raw_datum, ACPI_READ);
734                 if (ACPI_FAILURE(status)) {
735                         return_ACPI_STATUS(status);
736                 }
737
738                 /*
739                  * Merge with previous datum if necessary.
740                  *
741                  * Note: Before the shift, check if the shift value will be larger than
742                  * the integer size. If so, there is no need to perform the operation.
743                  * This avoids the differences in behavior between different compilers
744                  * concerning shift values larger than the target data width.
745                  */
746                 if ((obj_desc->common_field.access_bit_width -
747                      obj_desc->common_field.start_field_bit_offset) <
748                     ACPI_INTEGER_BIT_SIZE) {
749                         merged_datum |=
750                             raw_datum << (obj_desc->common_field.
751                                           access_bit_width -
752                                           obj_desc->common_field.
753                                           start_field_bit_offset);
754                 }
755
756                 if (i == datum_count) {
757                         break;
758                 }
759
760                 /* Write merged datum to target buffer */
761
762                 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
763                             ACPI_MIN(obj_desc->common_field.access_byte_width,
764                                      buffer_length - buffer_offset));
765
766                 buffer_offset += obj_desc->common_field.access_byte_width;
767                 merged_datum =
768                     raw_datum >> obj_desc->common_field.start_field_bit_offset;
769         }
770
771         /* Mask off any extra bits in the last datum */
772
773         buffer_tail_bits = obj_desc->common_field.bit_length %
774             obj_desc->common_field.access_bit_width;
775         if (buffer_tail_bits) {
776                 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
777         }
778
779         /* Write the last datum to the buffer */
780
781         ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
782                     ACPI_MIN(obj_desc->common_field.access_byte_width,
783                              buffer_length - buffer_offset));
784
785         return_ACPI_STATUS(AE_OK);
786 }
787
788 /*******************************************************************************
789  *
790  * FUNCTION:    acpi_ex_insert_into_field
791  *
792  * PARAMETERS:  obj_desc            - Field to be written
793  *              Buffer              - Data to be written
794  *              buffer_length       - Length of Buffer
795  *
796  * RETURN:      Status
797  *
798  * DESCRIPTION: Store the Buffer contents into the given field
799  *
800  ******************************************************************************/
801
802 acpi_status
803 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
804                           void *buffer, u32 buffer_length)
805 {
806         acpi_status status;
807         acpi_integer mask;
808         acpi_integer width_mask;
809         acpi_integer merged_datum;
810         acpi_integer raw_datum = 0;
811         u32 field_offset = 0;
812         u32 buffer_offset = 0;
813         u32 buffer_tail_bits;
814         u32 datum_count;
815         u32 field_datum_count;
816         u32 i;
817         u32 required_length;
818         void *new_buffer;
819
820         ACPI_FUNCTION_TRACE(ex_insert_into_field);
821
822         /* Validate input buffer */
823
824         new_buffer = NULL;
825         required_length =
826             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
827         /*
828          * We must have a buffer that is at least as long as the field
829          * we are writing to.  This is because individual fields are
830          * indivisible and partial writes are not supported -- as per
831          * the ACPI specification.
832          */
833         if (buffer_length < required_length) {
834
835                 /* We need to create a new buffer */
836
837                 new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
838                 if (!new_buffer) {
839                         return_ACPI_STATUS(AE_NO_MEMORY);
840                 }
841
842                 /*
843                  * Copy the original data to the new buffer, starting
844                  * at Byte zero.  All unused (upper) bytes of the
845                  * buffer will be 0.
846                  */
847                 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length);
848                 buffer = new_buffer;
849                 buffer_length = required_length;
850         }
851
852         /*
853          * Create the bitmasks used for bit insertion.
854          * Note: This if/else is used to bypass compiler differences with the
855          * shift operator
856          */
857         if (obj_desc->common_field.access_bit_width == ACPI_INTEGER_BIT_SIZE) {
858                 width_mask = ACPI_INTEGER_MAX;
859         } else {
860                 width_mask =
861                     ACPI_MASK_BITS_ABOVE(obj_desc->common_field.
862                                          access_bit_width);
863         }
864
865         mask = width_mask &
866             ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
867
868         /* Compute the number of datums (access width data items) */
869
870         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
871                                        obj_desc->common_field.access_bit_width);
872
873         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
874                                              obj_desc->common_field.
875                                              start_field_bit_offset,
876                                              obj_desc->common_field.
877                                              access_bit_width);
878
879         /* Get initial Datum from the input buffer */
880
881         ACPI_MEMCPY(&raw_datum, buffer,
882                     ACPI_MIN(obj_desc->common_field.access_byte_width,
883                              buffer_length - buffer_offset));
884
885         merged_datum =
886             raw_datum << obj_desc->common_field.start_field_bit_offset;
887
888         /* Write the entire field */
889
890         for (i = 1; i < field_datum_count; i++) {
891
892                 /* Write merged datum to the target field */
893
894                 merged_datum &= mask;
895                 status = acpi_ex_write_with_update_rule(obj_desc, mask,
896                                                         merged_datum,
897                                                         field_offset);
898                 if (ACPI_FAILURE(status)) {
899                         goto exit;
900                 }
901
902                 field_offset += obj_desc->common_field.access_byte_width;
903
904                 /*
905                  * Start new output datum by merging with previous input datum
906                  * if necessary.
907                  *
908                  * Note: Before the shift, check if the shift value will be larger than
909                  * the integer size. If so, there is no need to perform the operation.
910                  * This avoids the differences in behavior between different compilers
911                  * concerning shift values larger than the target data width.
912                  */
913                 if ((obj_desc->common_field.access_bit_width -
914                      obj_desc->common_field.start_field_bit_offset) <
915                     ACPI_INTEGER_BIT_SIZE) {
916                         merged_datum =
917                             raw_datum >> (obj_desc->common_field.
918                                           access_bit_width -
919                                           obj_desc->common_field.
920                                           start_field_bit_offset);
921                 } else {
922                         merged_datum = 0;
923                 }
924
925                 mask = width_mask;
926
927                 if (i == datum_count) {
928                         break;
929                 }
930
931                 /* Get the next input datum from the buffer */
932
933                 buffer_offset += obj_desc->common_field.access_byte_width;
934                 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset,
935                             ACPI_MIN(obj_desc->common_field.access_byte_width,
936                                      buffer_length - buffer_offset));
937                 merged_datum |=
938                     raw_datum << obj_desc->common_field.start_field_bit_offset;
939         }
940
941         /* Mask off any extra bits in the last datum */
942
943         buffer_tail_bits = (obj_desc->common_field.bit_length +
944                             obj_desc->common_field.start_field_bit_offset) %
945             obj_desc->common_field.access_bit_width;
946         if (buffer_tail_bits) {
947                 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
948         }
949
950         /* Write the last datum to the field */
951
952         merged_datum &= mask;
953         status = acpi_ex_write_with_update_rule(obj_desc,
954                                                 mask, merged_datum,
955                                                 field_offset);
956
957       exit:
958         /* Free temporary buffer if we used one */
959
960         if (new_buffer) {
961                 ACPI_FREE(new_buffer);
962         }
963         return_ACPI_STATUS(status);
964 }