Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
[linux-2.6] / drivers / acpi / executer / exfldio.c
1 /******************************************************************************
2  *
3  * Module Name: exfldio - Aml Field I/O
4  *
5  *****************************************************************************/
6
7 /*
8  * Copyright (C) 2000 - 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 <acpi/acinterp.h>
46 #include <acpi/amlcode.h>
47 #include <acpi/acevents.h>
48 #include <acpi/acdispat.h>
49
50 #define _COMPONENT          ACPI_EXECUTER
51 ACPI_MODULE_NAME("exfldio")
52
53 /* Local prototypes */
54 static acpi_status
55 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
56                        u32 field_datum_byte_offset,
57                        acpi_integer * value, u32 read_write);
58
59 static u8
60 acpi_ex_register_overflow(union acpi_operand_object *obj_desc,
61                           acpi_integer value);
62
63 static acpi_status
64 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
65                      u32 field_datum_byte_offset);
66
67 /*******************************************************************************
68  *
69  * FUNCTION:    acpi_ex_setup_region
70  *
71  * PARAMETERS:  obj_desc                - Field to be read or written
72  *              field_datum_byte_offset - Byte offset of this datum within the
73  *                                        parent field
74  *
75  * RETURN:      Status
76  *
77  * DESCRIPTION: Common processing for acpi_ex_extract_from_field and
78  *              acpi_ex_insert_into_field. Initialize the Region if necessary and
79  *              validate the request.
80  *
81  ******************************************************************************/
82
83 static acpi_status
84 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
85                      u32 field_datum_byte_offset)
86 {
87         acpi_status status = AE_OK;
88         union acpi_operand_object *rgn_desc;
89
90         ACPI_FUNCTION_TRACE_U32(ex_setup_region, field_datum_byte_offset);
91
92         rgn_desc = obj_desc->common_field.region_obj;
93
94         /* We must have a valid region */
95
96         if (ACPI_GET_OBJECT_TYPE(rgn_desc) != ACPI_TYPE_REGION) {
97                 ACPI_ERROR((AE_INFO, "Needed Region, found type %X (%s)",
98                             ACPI_GET_OBJECT_TYPE(rgn_desc),
99                             acpi_ut_get_object_type_name(rgn_desc)));
100
101                 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
102         }
103
104         /*
105          * If the Region Address and Length have not been previously evaluated,
106          * evaluate them now and save the results.
107          */
108         if (!(rgn_desc->common.flags & AOPOBJ_DATA_VALID)) {
109                 status = acpi_ds_get_region_arguments(rgn_desc);
110                 if (ACPI_FAILURE(status)) {
111                         return_ACPI_STATUS(status);
112                 }
113         }
114
115         /* Exit if Address/Length have been disallowed by the host OS */
116
117         if (rgn_desc->common.flags & AOPOBJ_INVALID) {
118                 return_ACPI_STATUS(AE_AML_ILLEGAL_ADDRESS);
119         }
120
121         /*
122          * Exit now for SMBus address space, it has a non-linear address space
123          * and the request cannot be directly validated
124          */
125         if (rgn_desc->region.space_id == ACPI_ADR_SPACE_SMBUS) {
126
127                 /* SMBus has a non-linear address space */
128
129                 return_ACPI_STATUS(AE_OK);
130         }
131 #ifdef ACPI_UNDER_DEVELOPMENT
132         /*
133          * If the Field access is any_acc, we can now compute the optimal
134          * access (because we know know the length of the parent region)
135          */
136         if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
137                 if (ACPI_FAILURE(status)) {
138                         return_ACPI_STATUS(status);
139                 }
140         }
141 #endif
142
143         /*
144          * Validate the request.  The entire request from the byte offset for a
145          * length of one field datum (access width) must fit within the region.
146          * (Region length is specified in bytes)
147          */
148         if (rgn_desc->region.length <
149             (obj_desc->common_field.base_byte_offset +
150              field_datum_byte_offset +
151              obj_desc->common_field.access_byte_width)) {
152                 if (acpi_gbl_enable_interpreter_slack) {
153                         /*
154                          * Slack mode only:  We will go ahead and allow access to this
155                          * field if it is within the region length rounded up to the next
156                          * access width boundary. acpi_size cast for 64-bit compile.
157                          */
158                         if (ACPI_ROUND_UP(rgn_desc->region.length,
159                                           obj_desc->common_field.
160                                           access_byte_width) >=
161                             ((acpi_size) obj_desc->common_field.
162                              base_byte_offset +
163                              obj_desc->common_field.access_byte_width +
164                              field_datum_byte_offset)) {
165                                 return_ACPI_STATUS(AE_OK);
166                         }
167                 }
168
169                 if (rgn_desc->region.length <
170                     obj_desc->common_field.access_byte_width) {
171                         /*
172                          * This is the case where the access_type (acc_word, etc.) is wider
173                          * than the region itself.  For example, a region of length one
174                          * byte, and a field with Dword access specified.
175                          */
176                         ACPI_ERROR((AE_INFO,
177                                     "Field [%4.4s] access width (%d bytes) too large for region [%4.4s] (length %X)",
178                                     acpi_ut_get_node_name(obj_desc->
179                                                           common_field.node),
180                                     obj_desc->common_field.access_byte_width,
181                                     acpi_ut_get_node_name(rgn_desc->region.
182                                                           node),
183                                     rgn_desc->region.length));
184                 }
185
186                 /*
187                  * Offset rounded up to next multiple of field width
188                  * exceeds region length, indicate an error
189                  */
190                 ACPI_ERROR((AE_INFO,
191                             "Field [%4.4s] Base+Offset+Width %X+%X+%X is beyond end of region [%4.4s] (length %X)",
192                             acpi_ut_get_node_name(obj_desc->common_field.node),
193                             obj_desc->common_field.base_byte_offset,
194                             field_datum_byte_offset,
195                             obj_desc->common_field.access_byte_width,
196                             acpi_ut_get_node_name(rgn_desc->region.node),
197                             rgn_desc->region.length));
198
199                 return_ACPI_STATUS(AE_AML_REGION_LIMIT);
200         }
201
202         return_ACPI_STATUS(AE_OK);
203 }
204
205 /*******************************************************************************
206  *
207  * FUNCTION:    acpi_ex_access_region
208  *
209  * PARAMETERS:  obj_desc                - Field to be read
210  *              field_datum_byte_offset - Byte offset of this datum within the
211  *                                        parent field
212  *              Value                   - Where to store value (must at least
213  *                                        the size of acpi_integer)
214  *              Function                - Read or Write flag plus other region-
215  *                                        dependent flags
216  *
217  * RETURN:      Status
218  *
219  * DESCRIPTION: Read or Write a single field datum to an Operation Region.
220  *
221  ******************************************************************************/
222
223 acpi_status
224 acpi_ex_access_region(union acpi_operand_object *obj_desc,
225                       u32 field_datum_byte_offset,
226                       acpi_integer * value, u32 function)
227 {
228         acpi_status status;
229         union acpi_operand_object *rgn_desc;
230         acpi_physical_address address;
231
232         ACPI_FUNCTION_TRACE(ex_access_region);
233
234         /*
235          * Ensure that the region operands are fully evaluated and verify
236          * the validity of the request
237          */
238         status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset);
239         if (ACPI_FAILURE(status)) {
240                 return_ACPI_STATUS(status);
241         }
242
243         /*
244          * The physical address of this field datum is:
245          *
246          * 1) The base of the region, plus
247          * 2) The base offset of the field, plus
248          * 3) The current offset into the field
249          */
250         rgn_desc = obj_desc->common_field.region_obj;
251         address = rgn_desc->region.address +
252             obj_desc->common_field.base_byte_offset + field_datum_byte_offset;
253
254         if ((function & ACPI_IO_MASK) == ACPI_READ) {
255                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
256         } else {
257                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
258         }
259
260         ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
261                               " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n",
262                               acpi_ut_get_region_name(rgn_desc->region.
263                                                       space_id),
264                               rgn_desc->region.space_id,
265                               obj_desc->common_field.access_byte_width,
266                               obj_desc->common_field.base_byte_offset,
267                               field_datum_byte_offset, ACPI_CAST_PTR(void,
268                                                                      address)));
269
270         /* Invoke the appropriate address_space/op_region handler */
271
272         status = acpi_ev_address_space_dispatch(rgn_desc, function,
273                                                 address,
274                                                 ACPI_MUL_8(obj_desc->
275                                                            common_field.
276                                                            access_byte_width),
277                                                 value);
278
279         if (ACPI_FAILURE(status)) {
280                 if (status == AE_NOT_IMPLEMENTED) {
281                         ACPI_ERROR((AE_INFO,
282                                     "Region %s(%X) not implemented",
283                                     acpi_ut_get_region_name(rgn_desc->region.
284                                                             space_id),
285                                     rgn_desc->region.space_id));
286                 } else if (status == AE_NOT_EXIST) {
287                         ACPI_ERROR((AE_INFO,
288                                     "Region %s(%X) has no handler",
289                                     acpi_ut_get_region_name(rgn_desc->region.
290                                                             space_id),
291                                     rgn_desc->region.space_id));
292                 }
293         }
294
295         return_ACPI_STATUS(status);
296 }
297
298 /*******************************************************************************
299  *
300  * FUNCTION:    acpi_ex_register_overflow
301  *
302  * PARAMETERS:  obj_desc                - Register(Field) to be written
303  *              Value                   - Value to be stored
304  *
305  * RETURN:      TRUE if value overflows the field, FALSE otherwise
306  *
307  * DESCRIPTION: Check if a value is out of range of the field being written.
308  *              Used to check if the values written to Index and Bank registers
309  *              are out of range.  Normally, the value is simply truncated
310  *              to fit the field, but this case is most likely a serious
311  *              coding error in the ASL.
312  *
313  ******************************************************************************/
314
315 static u8
316 acpi_ex_register_overflow(union acpi_operand_object *obj_desc,
317                           acpi_integer value)
318 {
319
320         if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
321                 /*
322                  * The field is large enough to hold the maximum integer, so we can
323                  * never overflow it.
324                  */
325                 return (FALSE);
326         }
327
328         if (value >= ((acpi_integer) 1 << obj_desc->common_field.bit_length)) {
329                 /*
330                  * The Value is larger than the maximum value that can fit into
331                  * the register.
332                  */
333                 return (TRUE);
334         }
335
336         /* The Value will fit into the field with no truncation */
337
338         return (FALSE);
339 }
340
341 /*******************************************************************************
342  *
343  * FUNCTION:    acpi_ex_field_datum_io
344  *
345  * PARAMETERS:  obj_desc                - Field to be read
346  *              field_datum_byte_offset - Byte offset of this datum within the
347  *                                        parent field
348  *              Value                   - Where to store value (must be 64 bits)
349  *              read_write              - Read or Write flag
350  *
351  * RETURN:      Status
352  *
353  * DESCRIPTION: Read or Write a single datum of a field.  The field_type is
354  *              demultiplexed here to handle the different types of fields
355  *              (buffer_field, region_field, index_field, bank_field)
356  *
357  ******************************************************************************/
358
359 static acpi_status
360 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
361                        u32 field_datum_byte_offset,
362                        acpi_integer * value, u32 read_write)
363 {
364         acpi_status status;
365         acpi_integer local_value;
366
367         ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
368
369         if (read_write == ACPI_READ) {
370                 if (!value) {
371                         local_value = 0;
372
373                         /* To support reads without saving return value */
374                         value = &local_value;
375                 }
376
377                 /* Clear the entire return buffer first, [Very Important!] */
378
379                 *value = 0;
380         }
381
382         /*
383          * The four types of fields are:
384          *
385          * buffer_field - Read/write from/to a Buffer
386          * region_field - Read/write from/to a Operation Region.
387          * bank_field  - Write to a Bank Register, then read/write from/to an
388          *               operation_region
389          * index_field - Write to an Index Register, then read/write from/to a
390          *               Data Register
391          */
392         switch (ACPI_GET_OBJECT_TYPE(obj_desc)) {
393         case ACPI_TYPE_BUFFER_FIELD:
394                 /*
395                  * If the buffer_field arguments have not been previously evaluated,
396                  * evaluate them now and save the results.
397                  */
398                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
399                         status = acpi_ds_get_buffer_field_arguments(obj_desc);
400                         if (ACPI_FAILURE(status)) {
401                                 return_ACPI_STATUS(status);
402                         }
403                 }
404
405                 if (read_write == ACPI_READ) {
406                         /*
407                          * Copy the data from the source buffer.
408                          * Length is the field width in bytes.
409                          */
410                         ACPI_MEMCPY(value,
411                                     (obj_desc->buffer_field.buffer_obj)->buffer.
412                                     pointer +
413                                     obj_desc->buffer_field.base_byte_offset +
414                                     field_datum_byte_offset,
415                                     obj_desc->common_field.access_byte_width);
416                 } else {
417                         /*
418                          * Copy the data to the target buffer.
419                          * Length is the field width in bytes.
420                          */
421                         ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer.
422                                     pointer +
423                                     obj_desc->buffer_field.base_byte_offset +
424                                     field_datum_byte_offset, value,
425                                     obj_desc->common_field.access_byte_width);
426                 }
427
428                 status = AE_OK;
429                 break;
430
431         case ACPI_TYPE_LOCAL_BANK_FIELD:
432
433                 /*
434                  * Ensure that the bank_value is not beyond the capacity of
435                  * the register
436                  */
437                 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
438                                               (acpi_integer) obj_desc->
439                                               bank_field.value)) {
440                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
441                 }
442
443                 /*
444                  * For bank_fields, we must write the bank_value to the bank_register
445                  * (itself a region_field) before we can access the data.
446                  */
447                 status =
448                     acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
449                                               &obj_desc->bank_field.value,
450                                               sizeof(obj_desc->bank_field.
451                                                      value));
452                 if (ACPI_FAILURE(status)) {
453                         return_ACPI_STATUS(status);
454                 }
455
456                 /*
457                  * Now that the Bank has been selected, fall through to the
458                  * region_field case and write the datum to the Operation Region
459                  */
460
461                 /*lint -fallthrough */
462
463         case ACPI_TYPE_LOCAL_REGION_FIELD:
464                 /*
465                  * For simple region_fields, we just directly access the owning
466                  * Operation Region.
467                  */
468                 status =
469                     acpi_ex_access_region(obj_desc, field_datum_byte_offset,
470                                           value, read_write);
471                 break;
472
473         case ACPI_TYPE_LOCAL_INDEX_FIELD:
474
475                 /*
476                  * Ensure that the index_value is not beyond the capacity of
477                  * the register
478                  */
479                 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
480                                               (acpi_integer) obj_desc->
481                                               index_field.value)) {
482                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
483                 }
484
485                 /* Write the index value to the index_register (itself a region_field) */
486
487                 field_datum_byte_offset += obj_desc->index_field.value;
488
489                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
490                                   "Write to Index Register: Value %8.8X\n",
491                                   field_datum_byte_offset));
492
493                 status =
494                     acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
495                                               &field_datum_byte_offset,
496                                               sizeof(field_datum_byte_offset));
497                 if (ACPI_FAILURE(status)) {
498                         return_ACPI_STATUS(status);
499                 }
500
501                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
502                                   "I/O to Data Register: ValuePtr %p\n",
503                                   value));
504
505                 if (read_write == ACPI_READ) {
506
507                         /* Read the datum from the data_register */
508
509                         status =
510                             acpi_ex_extract_from_field(obj_desc->index_field.
511                                                        data_obj, value,
512                                                        sizeof(acpi_integer));
513                 } else {
514                         /* Write the datum to the data_register */
515
516                         status =
517                             acpi_ex_insert_into_field(obj_desc->index_field.
518                                                       data_obj, value,
519                                                       sizeof(acpi_integer));
520                 }
521                 break;
522
523         default:
524
525                 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %X",
526                             ACPI_GET_OBJECT_TYPE(obj_desc)));
527                 status = AE_AML_INTERNAL;
528                 break;
529         }
530
531         if (ACPI_SUCCESS(status)) {
532                 if (read_write == ACPI_READ) {
533                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
534                                           "Value Read %8.8X%8.8X, Width %d\n",
535                                           ACPI_FORMAT_UINT64(*value),
536                                           obj_desc->common_field.
537                                           access_byte_width));
538                 } else {
539                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
540                                           "Value Written %8.8X%8.8X, Width %d\n",
541                                           ACPI_FORMAT_UINT64(*value),
542                                           obj_desc->common_field.
543                                           access_byte_width));
544                 }
545         }
546
547         return_ACPI_STATUS(status);
548 }
549
550 /*******************************************************************************
551  *
552  * FUNCTION:    acpi_ex_write_with_update_rule
553  *
554  * PARAMETERS:  obj_desc                - Field to be written
555  *              Mask                    - bitmask within field datum
556  *              field_value             - Value to write
557  *              field_datum_byte_offset - Offset of datum within field
558  *
559  * RETURN:      Status
560  *
561  * DESCRIPTION: Apply the field update rule to a field write
562  *
563  ******************************************************************************/
564
565 acpi_status
566 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc,
567                                acpi_integer mask,
568                                acpi_integer field_value,
569                                u32 field_datum_byte_offset)
570 {
571         acpi_status status = AE_OK;
572         acpi_integer merged_value;
573         acpi_integer current_value;
574
575         ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask);
576
577         /* Start with the new bits  */
578
579         merged_value = field_value;
580
581         /* If the mask is all ones, we don't need to worry about the update rule */
582
583         if (mask != ACPI_INTEGER_MAX) {
584
585                 /* Decode the update rule */
586
587                 switch (obj_desc->common_field.
588                         field_flags & AML_FIELD_UPDATE_RULE_MASK) {
589                 case AML_FIELD_UPDATE_PRESERVE:
590                         /*
591                          * Check if update rule needs to be applied (not if mask is all
592                          * ones)  The left shift drops the bits we want to ignore.
593                          */
594                         if ((~mask << (ACPI_MUL_8(sizeof(mask)) -
595                                        ACPI_MUL_8(obj_desc->common_field.
596                                                   access_byte_width))) != 0) {
597                                 /*
598                                  * Read the current contents of the byte/word/dword containing
599                                  * the field, and merge with the new field value.
600                                  */
601                                 status =
602                                     acpi_ex_field_datum_io(obj_desc,
603                                                            field_datum_byte_offset,
604                                                            &current_value,
605                                                            ACPI_READ);
606                                 if (ACPI_FAILURE(status)) {
607                                         return_ACPI_STATUS(status);
608                                 }
609
610                                 merged_value |= (current_value & ~mask);
611                         }
612                         break;
613
614                 case AML_FIELD_UPDATE_WRITE_AS_ONES:
615
616                         /* Set positions outside the field to all ones */
617
618                         merged_value |= ~mask;
619                         break;
620
621                 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
622
623                         /* Set positions outside the field to all zeros */
624
625                         merged_value &= mask;
626                         break;
627
628                 default:
629
630                         ACPI_ERROR((AE_INFO,
631                                     "Unknown UpdateRule value: %X",
632                                     (obj_desc->common_field.
633                                      field_flags &
634                                      AML_FIELD_UPDATE_RULE_MASK)));
635                         return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
636                 }
637         }
638
639         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
640                           "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
641                           ACPI_FORMAT_UINT64(mask),
642                           field_datum_byte_offset,
643                           obj_desc->common_field.access_byte_width,
644                           ACPI_FORMAT_UINT64(field_value),
645                           ACPI_FORMAT_UINT64(merged_value)));
646
647         /* Write the merged value */
648
649         status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset,
650                                         &merged_value, ACPI_WRITE);
651
652         return_ACPI_STATUS(status);
653 }
654
655 /*******************************************************************************
656  *
657  * FUNCTION:    acpi_ex_extract_from_field
658  *
659  * PARAMETERS:  obj_desc            - Field to be read
660  *              Buffer              - Where to store the field data
661  *              buffer_length       - Length of Buffer
662  *
663  * RETURN:      Status
664  *
665  * DESCRIPTION: Retrieve the current value of the given field
666  *
667  ******************************************************************************/
668
669 acpi_status
670 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
671                            void *buffer, u32 buffer_length)
672 {
673         acpi_status status;
674         acpi_integer raw_datum;
675         acpi_integer merged_datum;
676         u32 field_offset = 0;
677         u32 buffer_offset = 0;
678         u32 buffer_tail_bits;
679         u32 datum_count;
680         u32 field_datum_count;
681         u32 i;
682
683         ACPI_FUNCTION_TRACE(ex_extract_from_field);
684
685         /* Validate target buffer and clear it */
686
687         if (buffer_length <
688             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
689                 ACPI_ERROR((AE_INFO,
690                             "Field size %X (bits) is too large for buffer (%X)",
691                             obj_desc->common_field.bit_length, buffer_length));
692
693                 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
694         }
695         ACPI_MEMSET(buffer, 0, buffer_length);
696
697         /* Compute the number of datums (access width data items) */
698
699         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
700                                        obj_desc->common_field.access_bit_width);
701         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
702                                              obj_desc->common_field.
703                                              start_field_bit_offset,
704                                              obj_desc->common_field.
705                                              access_bit_width);
706
707         /* Priming read from the field */
708
709         status =
710             acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
711                                    ACPI_READ);
712         if (ACPI_FAILURE(status)) {
713                 return_ACPI_STATUS(status);
714         }
715         merged_datum =
716             raw_datum >> obj_desc->common_field.start_field_bit_offset;
717
718         /* Read the rest of the field */
719
720         for (i = 1; i < field_datum_count; i++) {
721
722                 /* Get next input datum from the field */
723
724                 field_offset += obj_desc->common_field.access_byte_width;
725                 status = acpi_ex_field_datum_io(obj_desc, field_offset,
726                                                 &raw_datum, ACPI_READ);
727                 if (ACPI_FAILURE(status)) {
728                         return_ACPI_STATUS(status);
729                 }
730
731                 /*
732                  * Merge with previous datum if necessary.
733                  *
734                  * Note: Before the shift, check if the shift value will be larger than
735                  * the integer size. If so, there is no need to perform the operation.
736                  * This avoids the differences in behavior between different compilers
737                  * concerning shift values larger than the target data width.
738                  */
739                 if ((obj_desc->common_field.access_bit_width -
740                      obj_desc->common_field.start_field_bit_offset) <
741                     ACPI_INTEGER_BIT_SIZE) {
742                         merged_datum |=
743                             raw_datum << (obj_desc->common_field.
744                                           access_bit_width -
745                                           obj_desc->common_field.
746                                           start_field_bit_offset);
747                 }
748
749                 if (i == datum_count) {
750                         break;
751                 }
752
753                 /* Write merged datum to target buffer */
754
755                 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
756                             ACPI_MIN(obj_desc->common_field.access_byte_width,
757                                      buffer_length - buffer_offset));
758
759                 buffer_offset += obj_desc->common_field.access_byte_width;
760                 merged_datum =
761                     raw_datum >> obj_desc->common_field.start_field_bit_offset;
762         }
763
764         /* Mask off any extra bits in the last datum */
765
766         buffer_tail_bits = obj_desc->common_field.bit_length %
767             obj_desc->common_field.access_bit_width;
768         if (buffer_tail_bits) {
769                 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
770         }
771
772         /* Write the last datum to the buffer */
773
774         ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
775                     ACPI_MIN(obj_desc->common_field.access_byte_width,
776                              buffer_length - buffer_offset));
777
778         return_ACPI_STATUS(AE_OK);
779 }
780
781 /*******************************************************************************
782  *
783  * FUNCTION:    acpi_ex_insert_into_field
784  *
785  * PARAMETERS:  obj_desc            - Field to be written
786  *              Buffer              - Data to be written
787  *              buffer_length       - Length of Buffer
788  *
789  * RETURN:      Status
790  *
791  * DESCRIPTION: Store the Buffer contents into the given field
792  *
793  ******************************************************************************/
794
795 acpi_status
796 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
797                           void *buffer, u32 buffer_length)
798 {
799         acpi_status status;
800         acpi_integer mask;
801         acpi_integer width_mask;
802         acpi_integer merged_datum;
803         acpi_integer raw_datum = 0;
804         u32 field_offset = 0;
805         u32 buffer_offset = 0;
806         u32 buffer_tail_bits;
807         u32 datum_count;
808         u32 field_datum_count;
809         u32 i;
810         u32 required_length;
811         void *new_buffer;
812
813         ACPI_FUNCTION_TRACE(ex_insert_into_field);
814
815         /* Validate input buffer */
816
817         new_buffer = NULL;
818         required_length =
819             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
820         /*
821          * We must have a buffer that is at least as long as the field
822          * we are writing to.  This is because individual fields are
823          * indivisible and partial writes are not supported -- as per
824          * the ACPI specification.
825          */
826         if (buffer_length < required_length) {
827
828                 /* We need to create a new buffer */
829
830                 new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
831                 if (!new_buffer) {
832                         return_ACPI_STATUS(AE_NO_MEMORY);
833                 }
834
835                 /*
836                  * Copy the original data to the new buffer, starting
837                  * at Byte zero.  All unused (upper) bytes of the
838                  * buffer will be 0.
839                  */
840                 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length);
841                 buffer = new_buffer;
842                 buffer_length = required_length;
843         }
844
845         /*
846          * Create the bitmasks used for bit insertion.
847          * Note: This if/else is used to bypass compiler differences with the
848          * shift operator
849          */
850         if (obj_desc->common_field.access_bit_width == ACPI_INTEGER_BIT_SIZE) {
851                 width_mask = ACPI_INTEGER_MAX;
852         } else {
853                 width_mask =
854                     ACPI_MASK_BITS_ABOVE(obj_desc->common_field.
855                                          access_bit_width);
856         }
857
858         mask = width_mask &
859             ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
860
861         /* Compute the number of datums (access width data items) */
862
863         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
864                                        obj_desc->common_field.access_bit_width);
865
866         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
867                                              obj_desc->common_field.
868                                              start_field_bit_offset,
869                                              obj_desc->common_field.
870                                              access_bit_width);
871
872         /* Get initial Datum from the input buffer */
873
874         ACPI_MEMCPY(&raw_datum, buffer,
875                     ACPI_MIN(obj_desc->common_field.access_byte_width,
876                              buffer_length - buffer_offset));
877
878         merged_datum =
879             raw_datum << obj_desc->common_field.start_field_bit_offset;
880
881         /* Write the entire field */
882
883         for (i = 1; i < field_datum_count; i++) {
884
885                 /* Write merged datum to the target field */
886
887                 merged_datum &= mask;
888                 status = acpi_ex_write_with_update_rule(obj_desc, mask,
889                                                         merged_datum,
890                                                         field_offset);
891                 if (ACPI_FAILURE(status)) {
892                         goto exit;
893                 }
894
895                 field_offset += obj_desc->common_field.access_byte_width;
896
897                 /*
898                  * Start new output datum by merging with previous input datum
899                  * if necessary.
900                  *
901                  * Note: Before the shift, check if the shift value will be larger than
902                  * the integer size. If so, there is no need to perform the operation.
903                  * This avoids the differences in behavior between different compilers
904                  * concerning shift values larger than the target data width.
905                  */
906                 if ((obj_desc->common_field.access_bit_width -
907                      obj_desc->common_field.start_field_bit_offset) <
908                     ACPI_INTEGER_BIT_SIZE) {
909                         merged_datum =
910                             raw_datum >> (obj_desc->common_field.
911                                           access_bit_width -
912                                           obj_desc->common_field.
913                                           start_field_bit_offset);
914                 } else {
915                         merged_datum = 0;
916                 }
917
918                 mask = width_mask;
919
920                 if (i == datum_count) {
921                         break;
922                 }
923
924                 /* Get the next input datum from the buffer */
925
926                 buffer_offset += obj_desc->common_field.access_byte_width;
927                 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset,
928                             ACPI_MIN(obj_desc->common_field.access_byte_width,
929                                      buffer_length - buffer_offset));
930                 merged_datum |=
931                     raw_datum << obj_desc->common_field.start_field_bit_offset;
932         }
933
934         /* Mask off any extra bits in the last datum */
935
936         buffer_tail_bits = (obj_desc->common_field.bit_length +
937                             obj_desc->common_field.start_field_bit_offset) %
938             obj_desc->common_field.access_bit_width;
939         if (buffer_tail_bits) {
940                 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
941         }
942
943         /* Write the last datum to the field */
944
945         merged_datum &= mask;
946         status = acpi_ex_write_with_update_rule(obj_desc,
947                                                 mask, merged_datum,
948                                                 field_offset);
949
950       exit:
951         /* Free temporary buffer if we used one */
952
953         if (new_buffer) {
954                 ACPI_FREE(new_buffer);
955         }
956         return_ACPI_STATUS(status);
957 }