Revert "ACPICA: Remove obsolete acpi_os_validate_address interface"
[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 - 2008, Intel Corp.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions, and the following disclaimer,
16  *    without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  *    substantially similar to the "NO WARRANTY" disclaimer below
19  *    ("Disclaimer") and any redistribution must be conditioned upon
20  *    including a substantially similar Disclaimer requirement for further
21  *    binary redistribution.
22  * 3. Neither the names of the above-listed copyright holders nor the names
23  *    of any contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * Alternatively, this software may be distributed under the terms of the
27  * GNU General Public License ("GPL") version 2 as published by the Free
28  * Software Foundation.
29  *
30  * NO WARRANTY
31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41  * POSSIBILITY OF SUCH DAMAGES.
42  */
43
44 #include <acpi/acpi.h>
45 #include "accommon.h"
46 #include "acinterp.h"
47 #include "amlcode.h"
48 #include "acevents.h"
49 #include "acdispat.h"
50
51 #define _COMPONENT          ACPI_EXECUTER
52 ACPI_MODULE_NAME("exfldio")
53
54 /* Local prototypes */
55 static acpi_status
56 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
57                        u32 field_datum_byte_offset,
58                        acpi_integer * value, u32 read_write);
59
60 static u8
61 acpi_ex_register_overflow(union acpi_operand_object *obj_desc,
62                           acpi_integer value);
63
64 static acpi_status
65 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
66                      u32 field_datum_byte_offset);
67
68 /*******************************************************************************
69  *
70  * FUNCTION:    acpi_ex_setup_region
71  *
72  * PARAMETERS:  obj_desc                - Field to be read or written
73  *              field_datum_byte_offset - Byte offset of this datum within the
74  *                                        parent field
75  *
76  * RETURN:      Status
77  *
78  * DESCRIPTION: Common processing for acpi_ex_extract_from_field and
79  *              acpi_ex_insert_into_field. Initialize the Region if necessary and
80  *              validate the request.
81  *
82  ******************************************************************************/
83
84 static acpi_status
85 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
86                      u32 field_datum_byte_offset)
87 {
88         acpi_status status = AE_OK;
89         union acpi_operand_object *rgn_desc;
90
91         ACPI_FUNCTION_TRACE_U32(ex_setup_region, field_datum_byte_offset);
92
93         rgn_desc = obj_desc->common_field.region_obj;
94
95         /* We must have a valid region */
96
97         if (rgn_desc->common.type != ACPI_TYPE_REGION) {
98                 ACPI_ERROR((AE_INFO, "Needed Region, found type %X (%s)",
99                             rgn_desc->common.type,
100                             acpi_ut_get_object_type_name(rgn_desc)));
101
102                 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
103         }
104
105         /*
106          * If the Region Address and Length have not been previously evaluated,
107          * evaluate them now and save the results.
108          */
109         if (!(rgn_desc->common.flags & AOPOBJ_DATA_VALID)) {
110                 status = acpi_ds_get_region_arguments(rgn_desc);
111                 if (ACPI_FAILURE(status)) {
112                         return_ACPI_STATUS(status);
113                 }
114         }
115
116         /* 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 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
128                 /* SMBus has a non-linear address space */
129
130                 return_ACPI_STATUS(AE_OK);
131         }
132 #ifdef ACPI_UNDER_DEVELOPMENT
133         /*
134          * If the Field access is any_acc, we can now compute the optimal
135          * access (because we know know the length of the parent region)
136          */
137         if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
138                 if (ACPI_FAILURE(status)) {
139                         return_ACPI_STATUS(status);
140                 }
141         }
142 #endif
143
144         /*
145          * Validate the request.  The entire request from the byte offset for a
146          * length of one field datum (access width) must fit within the region.
147          * (Region length is specified in bytes)
148          */
149         if (rgn_desc->region.length <
150             (obj_desc->common_field.base_byte_offset +
151              field_datum_byte_offset +
152              obj_desc->common_field.access_byte_width)) {
153                 if (acpi_gbl_enable_interpreter_slack) {
154                         /*
155                          * Slack mode only:  We will go ahead and allow access to this
156                          * field if it is within the region length rounded up to the next
157                          * access width boundary. acpi_size cast for 64-bit compile.
158                          */
159                         if (ACPI_ROUND_UP(rgn_desc->region.length,
160                                           obj_desc->common_field.
161                                           access_byte_width) >=
162                             ((acpi_size) obj_desc->common_field.
163                              base_byte_offset +
164                              obj_desc->common_field.access_byte_width +
165                              field_datum_byte_offset)) {
166                                 return_ACPI_STATUS(AE_OK);
167                         }
168                 }
169
170                 if (rgn_desc->region.length <
171                     obj_desc->common_field.access_byte_width) {
172                         /*
173                          * This is the case where the access_type (acc_word, etc.) is wider
174                          * than the region itself.  For example, a region of length one
175                          * byte, and a field with Dword access specified.
176                          */
177                         ACPI_ERROR((AE_INFO,
178                                     "Field [%4.4s] access width (%d bytes) too large for region [%4.4s] (length %X)",
179                                     acpi_ut_get_node_name(obj_desc->
180                                                           common_field.node),
181                                     obj_desc->common_field.access_byte_width,
182                                     acpi_ut_get_node_name(rgn_desc->region.
183                                                           node),
184                                     rgn_desc->region.length));
185                 }
186
187                 /*
188                  * Offset rounded up to next multiple of field width
189                  * exceeds region length, indicate an error
190                  */
191                 ACPI_ERROR((AE_INFO,
192                             "Field [%4.4s] Base+Offset+Width %X+%X+%X is beyond end of region [%4.4s] (length %X)",
193                             acpi_ut_get_node_name(obj_desc->common_field.node),
194                             obj_desc->common_field.base_byte_offset,
195                             field_datum_byte_offset,
196                             obj_desc->common_field.access_byte_width,
197                             acpi_ut_get_node_name(rgn_desc->region.node),
198                             rgn_desc->region.length));
199
200                 return_ACPI_STATUS(AE_AML_REGION_LIMIT);
201         }
202
203         return_ACPI_STATUS(AE_OK);
204 }
205
206 /*******************************************************************************
207  *
208  * FUNCTION:    acpi_ex_access_region
209  *
210  * PARAMETERS:  obj_desc                - Field to be read
211  *              field_datum_byte_offset - Byte offset of this datum within the
212  *                                        parent field
213  *              Value                   - Where to store value (must at least
214  *                                        the size of acpi_integer)
215  *              Function                - Read or Write flag plus other region-
216  *                                        dependent flags
217  *
218  * RETURN:      Status
219  *
220  * DESCRIPTION: Read or Write a single field datum to an Operation Region.
221  *
222  ******************************************************************************/
223
224 acpi_status
225 acpi_ex_access_region(union acpi_operand_object *obj_desc,
226                       u32 field_datum_byte_offset,
227                       acpi_integer * value, u32 function)
228 {
229         acpi_status status;
230         union acpi_operand_object *rgn_desc;
231         u32 region_offset;
232
233         ACPI_FUNCTION_TRACE(ex_access_region);
234
235         /*
236          * Ensure that the region operands are fully evaluated and verify
237          * the validity of the request
238          */
239         status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset);
240         if (ACPI_FAILURE(status)) {
241                 return_ACPI_STATUS(status);
242         }
243
244         /*
245          * The physical address of this field datum is:
246          *
247          * 1) The base of the region, plus
248          * 2) The base offset of the field, plus
249          * 3) The current offset into the field
250          */
251         rgn_desc = obj_desc->common_field.region_obj;
252         region_offset =
253             obj_desc->common_field.base_byte_offset + field_datum_byte_offset;
254
255         if ((function & ACPI_IO_MASK) == ACPI_READ) {
256                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
257         } else {
258                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
259         }
260
261         ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
262                               " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n",
263                               acpi_ut_get_region_name(rgn_desc->region.
264                                                       space_id),
265                               rgn_desc->region.space_id,
266                               obj_desc->common_field.access_byte_width,
267                               obj_desc->common_field.base_byte_offset,
268                               field_datum_byte_offset, ACPI_CAST_PTR(void,
269                                                                      (rgn_desc->
270                                                                       region.
271                                                                       address +
272                                                                       region_offset))));
273
274         /* Invoke the appropriate address_space/op_region handler */
275
276         status =
277             acpi_ev_address_space_dispatch(rgn_desc, function, region_offset,
278                                            ACPI_MUL_8(obj_desc->common_field.
279                                                       access_byte_width),
280                                            value);
281
282         if (ACPI_FAILURE(status)) {
283                 if (status == AE_NOT_IMPLEMENTED) {
284                         ACPI_ERROR((AE_INFO,
285                                     "Region %s(%X) not implemented",
286                                     acpi_ut_get_region_name(rgn_desc->region.
287                                                             space_id),
288                                     rgn_desc->region.space_id));
289                 } else if (status == AE_NOT_EXIST) {
290                         ACPI_ERROR((AE_INFO,
291                                     "Region %s(%X) has no handler",
292                                     acpi_ut_get_region_name(rgn_desc->region.
293                                                             space_id),
294                                     rgn_desc->region.space_id));
295                 }
296         }
297
298         return_ACPI_STATUS(status);
299 }
300
301 /*******************************************************************************
302  *
303  * FUNCTION:    acpi_ex_register_overflow
304  *
305  * PARAMETERS:  obj_desc                - Register(Field) to be written
306  *              Value                   - Value to be stored
307  *
308  * RETURN:      TRUE if value overflows the field, FALSE otherwise
309  *
310  * DESCRIPTION: Check if a value is out of range of the field being written.
311  *              Used to check if the values written to Index and Bank registers
312  *              are out of range.  Normally, the value is simply truncated
313  *              to fit the field, but this case is most likely a serious
314  *              coding error in the ASL.
315  *
316  ******************************************************************************/
317
318 static u8
319 acpi_ex_register_overflow(union acpi_operand_object *obj_desc,
320                           acpi_integer value)
321 {
322
323         if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
324                 /*
325                  * The field is large enough to hold the maximum integer, so we can
326                  * never overflow it.
327                  */
328                 return (FALSE);
329         }
330
331         if (value >= ((acpi_integer) 1 << obj_desc->common_field.bit_length)) {
332                 /*
333                  * The Value is larger than the maximum value that can fit into
334                  * the register.
335                  */
336                 return (TRUE);
337         }
338
339         /* The Value will fit into the field with no truncation */
340
341         return (FALSE);
342 }
343
344 /*******************************************************************************
345  *
346  * FUNCTION:    acpi_ex_field_datum_io
347  *
348  * PARAMETERS:  obj_desc                - Field to be read
349  *              field_datum_byte_offset - Byte offset of this datum within the
350  *                                        parent field
351  *              Value                   - Where to store value (must be 64 bits)
352  *              read_write              - Read or Write flag
353  *
354  * RETURN:      Status
355  *
356  * DESCRIPTION: Read or Write a single datum of a field.  The field_type is
357  *              demultiplexed here to handle the different types of fields
358  *              (buffer_field, region_field, index_field, bank_field)
359  *
360  ******************************************************************************/
361
362 static acpi_status
363 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
364                        u32 field_datum_byte_offset,
365                        acpi_integer * value, u32 read_write)
366 {
367         acpi_status status;
368         acpi_integer local_value;
369
370         ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
371
372         if (read_write == ACPI_READ) {
373                 if (!value) {
374                         local_value = 0;
375
376                         /* To support reads without saving return value */
377                         value = &local_value;
378                 }
379
380                 /* Clear the entire return buffer first, [Very Important!] */
381
382                 *value = 0;
383         }
384
385         /*
386          * The four types of fields are:
387          *
388          * buffer_field - Read/write from/to a Buffer
389          * region_field - Read/write from/to a Operation Region.
390          * bank_field  - Write to a Bank Register, then read/write from/to an
391          *               operation_region
392          * index_field - Write to an Index Register, then read/write from/to a
393          *               Data Register
394          */
395         switch (obj_desc->common.type) {
396         case ACPI_TYPE_BUFFER_FIELD:
397                 /*
398                  * If the buffer_field arguments have not been previously evaluated,
399                  * evaluate them now and save the results.
400                  */
401                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
402                         status = acpi_ds_get_buffer_field_arguments(obj_desc);
403                         if (ACPI_FAILURE(status)) {
404                                 return_ACPI_STATUS(status);
405                         }
406                 }
407
408                 if (read_write == ACPI_READ) {
409                         /*
410                          * Copy the data from the source buffer.
411                          * Length is the field width in bytes.
412                          */
413                         ACPI_MEMCPY(value,
414                                     (obj_desc->buffer_field.buffer_obj)->buffer.
415                                     pointer +
416                                     obj_desc->buffer_field.base_byte_offset +
417                                     field_datum_byte_offset,
418                                     obj_desc->common_field.access_byte_width);
419                 } else {
420                         /*
421                          * Copy the data to the target buffer.
422                          * Length is the field width in bytes.
423                          */
424                         ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer.
425                                     pointer +
426                                     obj_desc->buffer_field.base_byte_offset +
427                                     field_datum_byte_offset, value,
428                                     obj_desc->common_field.access_byte_width);
429                 }
430
431                 status = AE_OK;
432                 break;
433
434         case ACPI_TYPE_LOCAL_BANK_FIELD:
435
436                 /*
437                  * Ensure that the bank_value is not beyond the capacity of
438                  * the register
439                  */
440                 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
441                                               (acpi_integer) obj_desc->
442                                               bank_field.value)) {
443                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
444                 }
445
446                 /*
447                  * For bank_fields, we must write the bank_value to the bank_register
448                  * (itself a region_field) before we can access the data.
449                  */
450                 status =
451                     acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
452                                               &obj_desc->bank_field.value,
453                                               sizeof(obj_desc->bank_field.
454                                                      value));
455                 if (ACPI_FAILURE(status)) {
456                         return_ACPI_STATUS(status);
457                 }
458
459                 /*
460                  * Now that the Bank has been selected, fall through to the
461                  * region_field case and write the datum to the Operation Region
462                  */
463
464                 /*lint -fallthrough */
465
466         case ACPI_TYPE_LOCAL_REGION_FIELD:
467                 /*
468                  * For simple region_fields, we just directly access the owning
469                  * Operation Region.
470                  */
471                 status =
472                     acpi_ex_access_region(obj_desc, field_datum_byte_offset,
473                                           value, read_write);
474                 break;
475
476         case ACPI_TYPE_LOCAL_INDEX_FIELD:
477
478                 /*
479                  * Ensure that the index_value is not beyond the capacity of
480                  * the register
481                  */
482                 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
483                                               (acpi_integer) obj_desc->
484                                               index_field.value)) {
485                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
486                 }
487
488                 /* Write the index value to the index_register (itself a region_field) */
489
490                 field_datum_byte_offset += obj_desc->index_field.value;
491
492                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
493                                   "Write to Index Register: Value %8.8X\n",
494                                   field_datum_byte_offset));
495
496                 status =
497                     acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
498                                               &field_datum_byte_offset,
499                                               sizeof(field_datum_byte_offset));
500                 if (ACPI_FAILURE(status)) {
501                         return_ACPI_STATUS(status);
502                 }
503
504                 if (read_write == ACPI_READ) {
505
506                         /* Read the datum from the data_register */
507
508                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
509                                           "Read from Data Register\n"));
510
511                         status =
512                             acpi_ex_extract_from_field(obj_desc->index_field.
513                                                        data_obj, value,
514                                                        sizeof(acpi_integer));
515                 } else {
516                         /* Write the datum to the data_register */
517
518                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
519                                           "Write to Data Register: Value %8.8X%8.8X\n",
520                                           ACPI_FORMAT_UINT64(*value)));
521
522                         status =
523                             acpi_ex_insert_into_field(obj_desc->index_field.
524                                                       data_obj, value,
525                                                       sizeof(acpi_integer));
526                 }
527                 break;
528
529         default:
530
531                 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %X",
532                             obj_desc->common.type));
533                 status = AE_AML_INTERNAL;
534                 break;
535         }
536
537         if (ACPI_SUCCESS(status)) {
538                 if (read_write == ACPI_READ) {
539                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
540                                           "Value Read %8.8X%8.8X, Width %d\n",
541                                           ACPI_FORMAT_UINT64(*value),
542                                           obj_desc->common_field.
543                                           access_byte_width));
544                 } else {
545                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
546                                           "Value Written %8.8X%8.8X, Width %d\n",
547                                           ACPI_FORMAT_UINT64(*value),
548                                           obj_desc->common_field.
549                                           access_byte_width));
550                 }
551         }
552
553         return_ACPI_STATUS(status);
554 }
555
556 /*******************************************************************************
557  *
558  * FUNCTION:    acpi_ex_write_with_update_rule
559  *
560  * PARAMETERS:  obj_desc                - Field to be written
561  *              Mask                    - bitmask within field datum
562  *              field_value             - Value to write
563  *              field_datum_byte_offset - Offset of datum within field
564  *
565  * RETURN:      Status
566  *
567  * DESCRIPTION: Apply the field update rule to a field write
568  *
569  ******************************************************************************/
570
571 acpi_status
572 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc,
573                                acpi_integer mask,
574                                acpi_integer field_value,
575                                u32 field_datum_byte_offset)
576 {
577         acpi_status status = AE_OK;
578         acpi_integer merged_value;
579         acpi_integer current_value;
580
581         ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask);
582
583         /* Start with the new bits  */
584
585         merged_value = field_value;
586
587         /* If the mask is all ones, we don't need to worry about the update rule */
588
589         if (mask != ACPI_INTEGER_MAX) {
590
591                 /* Decode the update rule */
592
593                 switch (obj_desc->common_field.
594                         field_flags & AML_FIELD_UPDATE_RULE_MASK) {
595                 case AML_FIELD_UPDATE_PRESERVE:
596                         /*
597                          * Check if update rule needs to be applied (not if mask is all
598                          * ones)  The left shift drops the bits we want to ignore.
599                          */
600                         if ((~mask << (ACPI_MUL_8(sizeof(mask)) -
601                                        ACPI_MUL_8(obj_desc->common_field.
602                                                   access_byte_width))) != 0) {
603                                 /*
604                                  * Read the current contents of the byte/word/dword containing
605                                  * the field, and merge with the new field value.
606                                  */
607                                 status =
608                                     acpi_ex_field_datum_io(obj_desc,
609                                                            field_datum_byte_offset,
610                                                            &current_value,
611                                                            ACPI_READ);
612                                 if (ACPI_FAILURE(status)) {
613                                         return_ACPI_STATUS(status);
614                                 }
615
616                                 merged_value |= (current_value & ~mask);
617                         }
618                         break;
619
620                 case AML_FIELD_UPDATE_WRITE_AS_ONES:
621
622                         /* Set positions outside the field to all ones */
623
624                         merged_value |= ~mask;
625                         break;
626
627                 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
628
629                         /* Set positions outside the field to all zeros */
630
631                         merged_value &= mask;
632                         break;
633
634                 default:
635
636                         ACPI_ERROR((AE_INFO,
637                                     "Unknown UpdateRule value: %X",
638                                     (obj_desc->common_field.
639                                      field_flags &
640                                      AML_FIELD_UPDATE_RULE_MASK)));
641                         return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
642                 }
643         }
644
645         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
646                           "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
647                           ACPI_FORMAT_UINT64(mask),
648                           field_datum_byte_offset,
649                           obj_desc->common_field.access_byte_width,
650                           ACPI_FORMAT_UINT64(field_value),
651                           ACPI_FORMAT_UINT64(merged_value)));
652
653         /* Write the merged value */
654
655         status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset,
656                                         &merged_value, ACPI_WRITE);
657
658         return_ACPI_STATUS(status);
659 }
660
661 /*******************************************************************************
662  *
663  * FUNCTION:    acpi_ex_extract_from_field
664  *
665  * PARAMETERS:  obj_desc            - Field to be read
666  *              Buffer              - Where to store the field data
667  *              buffer_length       - Length of Buffer
668  *
669  * RETURN:      Status
670  *
671  * DESCRIPTION: Retrieve the current value of the given field
672  *
673  ******************************************************************************/
674
675 acpi_status
676 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
677                            void *buffer, u32 buffer_length)
678 {
679         acpi_status status;
680         acpi_integer raw_datum;
681         acpi_integer merged_datum;
682         u32 field_offset = 0;
683         u32 buffer_offset = 0;
684         u32 buffer_tail_bits;
685         u32 datum_count;
686         u32 field_datum_count;
687         u32 i;
688
689         ACPI_FUNCTION_TRACE(ex_extract_from_field);
690
691         /* Validate target buffer and clear it */
692
693         if (buffer_length <
694             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
695                 ACPI_ERROR((AE_INFO,
696                             "Field size %X (bits) is too large for buffer (%X)",
697                             obj_desc->common_field.bit_length, buffer_length));
698
699                 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
700         }
701         ACPI_MEMSET(buffer, 0, buffer_length);
702
703         /* Compute the number of datums (access width data items) */
704
705         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
706                                        obj_desc->common_field.access_bit_width);
707         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
708                                              obj_desc->common_field.
709                                              start_field_bit_offset,
710                                              obj_desc->common_field.
711                                              access_bit_width);
712
713         /* Priming read from the field */
714
715         status =
716             acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
717                                    ACPI_READ);
718         if (ACPI_FAILURE(status)) {
719                 return_ACPI_STATUS(status);
720         }
721         merged_datum =
722             raw_datum >> obj_desc->common_field.start_field_bit_offset;
723
724         /* Read the rest of the field */
725
726         for (i = 1; i < field_datum_count; i++) {
727
728                 /* Get next input datum from the field */
729
730                 field_offset += obj_desc->common_field.access_byte_width;
731                 status = acpi_ex_field_datum_io(obj_desc, field_offset,
732                                                 &raw_datum, ACPI_READ);
733                 if (ACPI_FAILURE(status)) {
734                         return_ACPI_STATUS(status);
735                 }
736
737                 /*
738                  * Merge with previous datum if necessary.
739                  *
740                  * Note: Before the shift, check if the shift value will be larger than
741                  * the integer size. If so, there is no need to perform the operation.
742                  * This avoids the differences in behavior between different compilers
743                  * concerning shift values larger than the target data width.
744                  */
745                 if ((obj_desc->common_field.access_bit_width -
746                      obj_desc->common_field.start_field_bit_offset) <
747                     ACPI_INTEGER_BIT_SIZE) {
748                         merged_datum |=
749                             raw_datum << (obj_desc->common_field.
750                                           access_bit_width -
751                                           obj_desc->common_field.
752                                           start_field_bit_offset);
753                 }
754
755                 if (i == datum_count) {
756                         break;
757                 }
758
759                 /* Write merged datum to target buffer */
760
761                 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
762                             ACPI_MIN(obj_desc->common_field.access_byte_width,
763                                      buffer_length - buffer_offset));
764
765                 buffer_offset += obj_desc->common_field.access_byte_width;
766                 merged_datum =
767                     raw_datum >> obj_desc->common_field.start_field_bit_offset;
768         }
769
770         /* Mask off any extra bits in the last datum */
771
772         buffer_tail_bits = obj_desc->common_field.bit_length %
773             obj_desc->common_field.access_bit_width;
774         if (buffer_tail_bits) {
775                 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
776         }
777
778         /* Write the last datum to the buffer */
779
780         ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
781                     ACPI_MIN(obj_desc->common_field.access_byte_width,
782                              buffer_length - buffer_offset));
783
784         return_ACPI_STATUS(AE_OK);
785 }
786
787 /*******************************************************************************
788  *
789  * FUNCTION:    acpi_ex_insert_into_field
790  *
791  * PARAMETERS:  obj_desc            - Field to be written
792  *              Buffer              - Data to be written
793  *              buffer_length       - Length of Buffer
794  *
795  * RETURN:      Status
796  *
797  * DESCRIPTION: Store the Buffer contents into the given field
798  *
799  ******************************************************************************/
800
801 acpi_status
802 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
803                           void *buffer, u32 buffer_length)
804 {
805         acpi_status status;
806         acpi_integer mask;
807         acpi_integer width_mask;
808         acpi_integer merged_datum;
809         acpi_integer raw_datum = 0;
810         u32 field_offset = 0;
811         u32 buffer_offset = 0;
812         u32 buffer_tail_bits;
813         u32 datum_count;
814         u32 field_datum_count;
815         u32 i;
816         u32 required_length;
817         void *new_buffer;
818
819         ACPI_FUNCTION_TRACE(ex_insert_into_field);
820
821         /* Validate input buffer */
822
823         new_buffer = NULL;
824         required_length =
825             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
826         /*
827          * We must have a buffer that is at least as long as the field
828          * we are writing to.  This is because individual fields are
829          * indivisible and partial writes are not supported -- as per
830          * the ACPI specification.
831          */
832         if (buffer_length < required_length) {
833
834                 /* We need to create a new buffer */
835
836                 new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
837                 if (!new_buffer) {
838                         return_ACPI_STATUS(AE_NO_MEMORY);
839                 }
840
841                 /*
842                  * Copy the original data to the new buffer, starting
843                  * at Byte zero.  All unused (upper) bytes of the
844                  * buffer will be 0.
845                  */
846                 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length);
847                 buffer = new_buffer;
848                 buffer_length = required_length;
849         }
850
851         /*
852          * Create the bitmasks used for bit insertion.
853          * Note: This if/else is used to bypass compiler differences with the
854          * shift operator
855          */
856         if (obj_desc->common_field.access_bit_width == ACPI_INTEGER_BIT_SIZE) {
857                 width_mask = ACPI_INTEGER_MAX;
858         } else {
859                 width_mask =
860                     ACPI_MASK_BITS_ABOVE(obj_desc->common_field.
861                                          access_bit_width);
862         }
863
864         mask = width_mask &
865             ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
866
867         /* Compute the number of datums (access width data items) */
868
869         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
870                                        obj_desc->common_field.access_bit_width);
871
872         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
873                                              obj_desc->common_field.
874                                              start_field_bit_offset,
875                                              obj_desc->common_field.
876                                              access_bit_width);
877
878         /* Get initial Datum from the input buffer */
879
880         ACPI_MEMCPY(&raw_datum, buffer,
881                     ACPI_MIN(obj_desc->common_field.access_byte_width,
882                              buffer_length - buffer_offset));
883
884         merged_datum =
885             raw_datum << obj_desc->common_field.start_field_bit_offset;
886
887         /* Write the entire field */
888
889         for (i = 1; i < field_datum_count; i++) {
890
891                 /* Write merged datum to the target field */
892
893                 merged_datum &= mask;
894                 status = acpi_ex_write_with_update_rule(obj_desc, mask,
895                                                         merged_datum,
896                                                         field_offset);
897                 if (ACPI_FAILURE(status)) {
898                         goto exit;
899                 }
900
901                 field_offset += obj_desc->common_field.access_byte_width;
902
903                 /*
904                  * Start new output datum by merging with previous input datum
905                  * if necessary.
906                  *
907                  * Note: Before the shift, check if the shift value will be larger than
908                  * the integer size. If so, there is no need to perform the operation.
909                  * This avoids the differences in behavior between different compilers
910                  * concerning shift values larger than the target data width.
911                  */
912                 if ((obj_desc->common_field.access_bit_width -
913                      obj_desc->common_field.start_field_bit_offset) <
914                     ACPI_INTEGER_BIT_SIZE) {
915                         merged_datum =
916                             raw_datum >> (obj_desc->common_field.
917                                           access_bit_width -
918                                           obj_desc->common_field.
919                                           start_field_bit_offset);
920                 } else {
921                         merged_datum = 0;
922                 }
923
924                 mask = width_mask;
925
926                 if (i == datum_count) {
927                         break;
928                 }
929
930                 /* Get the next input datum from the buffer */
931
932                 buffer_offset += obj_desc->common_field.access_byte_width;
933                 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset,
934                             ACPI_MIN(obj_desc->common_field.access_byte_width,
935                                      buffer_length - buffer_offset));
936                 merged_datum |=
937                     raw_datum << obj_desc->common_field.start_field_bit_offset;
938         }
939
940         /* Mask off any extra bits in the last datum */
941
942         buffer_tail_bits = (obj_desc->common_field.bit_length +
943                             obj_desc->common_field.start_field_bit_offset) %
944             obj_desc->common_field.access_bit_width;
945         if (buffer_tail_bits) {
946                 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
947         }
948
949         /* Write the last datum to the field */
950
951         merged_datum &= mask;
952         status = acpi_ex_write_with_update_rule(obj_desc,
953                                                 mask, merged_datum,
954                                                 field_offset);
955
956       exit:
957         /* Free temporary buffer if we used one */
958
959         if (new_buffer) {
960                 ACPI_FREE(new_buffer);
961         }
962         return_ACPI_STATUS(status);
963 }