a226f74d4a5cddeaf12cdf7cadeba48419b1b3ba
[linux-2.6.git] / drivers / acpi / acpica / exprep.c
1
2 /******************************************************************************
3  *
4  * Module Name: exprep - ACPI AML (p-code) execution - field prep utilities
5  *
6  *****************************************************************************/
7
8 /*
9  * Copyright (C) 2000 - 2008, Intel Corp.
10  * All rights reserved.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions, and the following disclaimer,
17  *    without modification.
18  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
19  *    substantially similar to the "NO WARRANTY" disclaimer below
20  *    ("Disclaimer") and any redistribution must be conditioned upon
21  *    including a substantially similar Disclaimer requirement for further
22  *    binary redistribution.
23  * 3. Neither the names of the above-listed copyright holders nor the names
24  *    of any contributors may be used to endorse or promote products derived
25  *    from this software without specific prior written permission.
26  *
27  * Alternatively, this software may be distributed under the terms of the
28  * GNU General Public License ("GPL") version 2 as published by the Free
29  * Software Foundation.
30  *
31  * NO WARRANTY
32  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
33  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
34  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
35  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
36  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
40  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
41  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
42  * POSSIBILITY OF SUCH DAMAGES.
43  */
44
45 #include <acpi/acpi.h>
46 #include "accommon.h"
47 #include "acinterp.h"
48 #include "amlcode.h"
49 #include "acnamesp.h"
50
51 #define _COMPONENT          ACPI_EXECUTER
52 ACPI_MODULE_NAME("exprep")
53
54 /* Local prototypes */
55 static u32
56 acpi_ex_decode_field_access(union acpi_operand_object *obj_desc,
57                             u8 field_flags, u32 * return_byte_alignment);
58
59 #ifdef ACPI_UNDER_DEVELOPMENT
60
61 static u32
62 acpi_ex_generate_access(u32 field_bit_offset,
63                         u32 field_bit_length, u32 region_length);
64
65 /*******************************************************************************
66  *
67  * FUNCTION:    acpi_ex_generate_access
68  *
69  * PARAMETERS:  field_bit_offset    - Start of field within parent region/buffer
70  *              field_bit_length    - Length of field in bits
71  *              region_length       - Length of parent in bytes
72  *
73  * RETURN:      Field granularity (8, 16, 32 or 64) and
74  *              byte_alignment (1, 2, 3, or 4)
75  *
76  * DESCRIPTION: Generate an optimal access width for fields defined with the
77  *              any_acc keyword.
78  *
79  * NOTE: Need to have the region_length in order to check for boundary
80  *       conditions (end-of-region).  However, the region_length is a deferred
81  *       operation.  Therefore, to complete this implementation, the generation
82  *       of this access width must be deferred until the region length has
83  *       been evaluated.
84  *
85  ******************************************************************************/
86
87 static u32
88 acpi_ex_generate_access(u32 field_bit_offset,
89                         u32 field_bit_length, u32 region_length)
90 {
91         u32 field_byte_length;
92         u32 field_byte_offset;
93         u32 field_byte_end_offset;
94         u32 access_byte_width;
95         u32 field_start_offset;
96         u32 field_end_offset;
97         u32 minimum_access_width = 0xFFFFFFFF;
98         u32 minimum_accesses = 0xFFFFFFFF;
99         u32 accesses;
100
101         ACPI_FUNCTION_TRACE(ex_generate_access);
102
103         /* Round Field start offset and length to "minimal" byte boundaries */
104
105         field_byte_offset = ACPI_DIV_8(ACPI_ROUND_DOWN(field_bit_offset, 8));
106         field_byte_end_offset = ACPI_DIV_8(ACPI_ROUND_UP(field_bit_length +
107                                                          field_bit_offset, 8));
108         field_byte_length = field_byte_end_offset - field_byte_offset;
109
110         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
111                           "Bit length %d, Bit offset %d\n",
112                           field_bit_length, field_bit_offset));
113
114         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
115                           "Byte Length %d, Byte Offset %d, End Offset %d\n",
116                           field_byte_length, field_byte_offset,
117                           field_byte_end_offset));
118
119         /*
120          * Iterative search for the maximum access width that is both aligned
121          * and does not go beyond the end of the region
122          *
123          * Start at byte_acc and work upwards to qword_acc max. (1,2,4,8 bytes)
124          */
125         for (access_byte_width = 1; access_byte_width <= 8;
126              access_byte_width <<= 1) {
127                 /*
128                  * 1) Round end offset up to next access boundary and make sure that
129                  *    this does not go beyond the end of the parent region.
130                  * 2) When the Access width is greater than the field_byte_length, we
131                  *    are done. (This does not optimize for the perfectly aligned
132                  *    case yet).
133                  */
134                 if (ACPI_ROUND_UP(field_byte_end_offset, access_byte_width) <=
135                     region_length) {
136                         field_start_offset =
137                             ACPI_ROUND_DOWN(field_byte_offset,
138                                             access_byte_width) /
139                             access_byte_width;
140
141                         field_end_offset =
142                             ACPI_ROUND_UP((field_byte_length +
143                                            field_byte_offset),
144                                           access_byte_width) /
145                             access_byte_width;
146
147                         accesses = field_end_offset - field_start_offset;
148
149                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
150                                           "AccessWidth %d end is within region\n",
151                                           access_byte_width));
152
153                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
154                                           "Field Start %d, Field End %d -- requires %d accesses\n",
155                                           field_start_offset, field_end_offset,
156                                           accesses));
157
158                         /* Single access is optimal */
159
160                         if (accesses <= 1) {
161                                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
162                                                   "Entire field can be accessed with one operation of size %d\n",
163                                                   access_byte_width));
164                                 return_VALUE(access_byte_width);
165                         }
166
167                         /*
168                          * Fits in the region, but requires more than one read/write.
169                          * try the next wider access on next iteration
170                          */
171                         if (accesses < minimum_accesses) {
172                                 minimum_accesses = accesses;
173                                 minimum_access_width = access_byte_width;
174                         }
175                 } else {
176                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
177                                           "AccessWidth %d end is NOT within region\n",
178                                           access_byte_width));
179                         if (access_byte_width == 1) {
180                                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
181                                                   "Field goes beyond end-of-region!\n"));
182
183                                 /* Field does not fit in the region at all */
184
185                                 return_VALUE(0);
186                         }
187
188                         /*
189                          * This width goes beyond the end-of-region, back off to
190                          * previous access
191                          */
192                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
193                                           "Backing off to previous optimal access width of %d\n",
194                                           minimum_access_width));
195                         return_VALUE(minimum_access_width);
196                 }
197         }
198
199         /*
200          * Could not read/write field with one operation,
201          * just use max access width
202          */
203         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
204                           "Cannot access field in one operation, using width 8\n"));
205         return_VALUE(8);
206 }
207 #endif                          /* ACPI_UNDER_DEVELOPMENT */
208
209 /*******************************************************************************
210  *
211  * FUNCTION:    acpi_ex_decode_field_access
212  *
213  * PARAMETERS:  obj_desc            - Field object
214  *              field_flags         - Encoded fieldflags (contains access bits)
215  *              return_byte_alignment - Where the byte alignment is returned
216  *
217  * RETURN:      Field granularity (8, 16, 32 or 64) and
218  *              byte_alignment (1, 2, 3, or 4)
219  *
220  * DESCRIPTION: Decode the access_type bits of a field definition.
221  *
222  ******************************************************************************/
223
224 static u32
225 acpi_ex_decode_field_access(union acpi_operand_object *obj_desc,
226                             u8 field_flags, u32 * return_byte_alignment)
227 {
228         u32 access;
229         u32 byte_alignment;
230         u32 bit_length;
231
232         ACPI_FUNCTION_TRACE(ex_decode_field_access);
233
234         access = (field_flags & AML_FIELD_ACCESS_TYPE_MASK);
235
236         switch (access) {
237         case AML_FIELD_ACCESS_ANY:
238
239 #ifdef ACPI_UNDER_DEVELOPMENT
240                 byte_alignment =
241                     acpi_ex_generate_access(obj_desc->common_field.
242                                             start_field_bit_offset,
243                                             obj_desc->common_field.bit_length,
244                                             0xFFFFFFFF
245                                             /* Temp until we pass region_length as parameter */
246                     );
247                 bit_length = byte_alignment * 8;
248 #endif
249
250                 byte_alignment = 1;
251                 bit_length = 8;
252                 break;
253
254         case AML_FIELD_ACCESS_BYTE:
255         case AML_FIELD_ACCESS_BUFFER:   /* ACPI 2.0 (SMBus Buffer) */
256                 byte_alignment = 1;
257                 bit_length = 8;
258                 break;
259
260         case AML_FIELD_ACCESS_WORD:
261                 byte_alignment = 2;
262                 bit_length = 16;
263                 break;
264
265         case AML_FIELD_ACCESS_DWORD:
266                 byte_alignment = 4;
267                 bit_length = 32;
268                 break;
269
270         case AML_FIELD_ACCESS_QWORD:    /* ACPI 2.0 */
271                 byte_alignment = 8;
272                 bit_length = 64;
273                 break;
274
275         default:
276                 /* Invalid field access type */
277
278                 ACPI_ERROR((AE_INFO, "Unknown field access type %X", access));
279                 return_UINT32(0);
280         }
281
282         if (ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_BUFFER_FIELD) {
283                 /*
284                  * buffer_field access can be on any byte boundary, so the
285                  * byte_alignment is always 1 byte -- regardless of any byte_alignment
286                  * implied by the field access type.
287                  */
288                 byte_alignment = 1;
289         }
290
291         *return_byte_alignment = byte_alignment;
292         return_UINT32(bit_length);
293 }
294
295 /*******************************************************************************
296  *
297  * FUNCTION:    acpi_ex_prep_common_field_object
298  *
299  * PARAMETERS:  obj_desc            - The field object
300  *              field_flags         - Access, lock_rule, and update_rule.
301  *                                    The format of a field_flag is described
302  *                                    in the ACPI specification
303  *              field_attribute     - Special attributes (not used)
304  *              field_bit_position  - Field start position
305  *              field_bit_length    - Field length in number of bits
306  *
307  * RETURN:      Status
308  *
309  * DESCRIPTION: Initialize the areas of the field object that are common
310  *              to the various types of fields.  Note: This is very "sensitive"
311  *              code because we are solving the general case for field
312  *              alignment.
313  *
314  ******************************************************************************/
315
316 acpi_status
317 acpi_ex_prep_common_field_object(union acpi_operand_object *obj_desc,
318                                  u8 field_flags,
319                                  u8 field_attribute,
320                                  u32 field_bit_position, u32 field_bit_length)
321 {
322         u32 access_bit_width;
323         u32 byte_alignment;
324         u32 nearest_byte_address;
325
326         ACPI_FUNCTION_TRACE(ex_prep_common_field_object);
327
328         /*
329          * Note: the structure being initialized is the
330          * ACPI_COMMON_FIELD_INFO;  No structure fields outside of the common
331          * area are initialized by this procedure.
332          */
333         obj_desc->common_field.field_flags = field_flags;
334         obj_desc->common_field.attribute = field_attribute;
335         obj_desc->common_field.bit_length = field_bit_length;
336
337         /*
338          * Decode the access type so we can compute offsets.  The access type gives
339          * two pieces of information - the width of each field access and the
340          * necessary byte_alignment (address granularity) of the access.
341          *
342          * For any_acc, the access_bit_width is the largest width that is both
343          * necessary and possible in an attempt to access the whole field in one
344          * I/O operation.  However, for any_acc, the byte_alignment is always one
345          * byte.
346          *
347          * For all Buffer Fields, the byte_alignment is always one byte.
348          *
349          * For all other access types (Byte, Word, Dword, Qword), the Bitwidth is
350          * the same (equivalent) as the byte_alignment.
351          */
352         access_bit_width = acpi_ex_decode_field_access(obj_desc, field_flags,
353                                                        &byte_alignment);
354         if (!access_bit_width) {
355                 return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
356         }
357
358         /* Setup width (access granularity) fields */
359
360         obj_desc->common_field.access_byte_width = (u8)
361             ACPI_DIV_8(access_bit_width);       /* 1,  2,  4,  8 */
362
363         obj_desc->common_field.access_bit_width = (u8) access_bit_width;
364
365         /*
366          * base_byte_offset is the address of the start of the field within the
367          * region.  It is the byte address of the first *datum* (field-width data
368          * unit) of the field. (i.e., the first datum that contains at least the
369          * first *bit* of the field.)
370          *
371          * Note: byte_alignment is always either equal to the access_bit_width or 8
372          * (Byte access), and it defines the addressing granularity of the parent
373          * region or buffer.
374          */
375         nearest_byte_address =
376             ACPI_ROUND_BITS_DOWN_TO_BYTES(field_bit_position);
377         obj_desc->common_field.base_byte_offset = (u32)
378             ACPI_ROUND_DOWN(nearest_byte_address, byte_alignment);
379
380         /*
381          * start_field_bit_offset is the offset of the first bit of the field within
382          * a field datum.
383          */
384         obj_desc->common_field.start_field_bit_offset = (u8)
385             (field_bit_position -
386              ACPI_MUL_8(obj_desc->common_field.base_byte_offset));
387
388         /*
389          * Does the entire field fit within a single field access element? (datum)
390          * (i.e., without crossing a datum boundary)
391          */
392         if ((obj_desc->common_field.start_field_bit_offset +
393              field_bit_length) <= (u16) access_bit_width) {
394                 obj_desc->common.flags |= AOPOBJ_SINGLE_DATUM;
395         }
396
397         return_ACPI_STATUS(AE_OK);
398 }
399
400 /*******************************************************************************
401  *
402  * FUNCTION:    acpi_ex_prep_field_value
403  *
404  * PARAMETERS:  Info    - Contains all field creation info
405  *
406  * RETURN:      Status
407  *
408  * DESCRIPTION: Construct a union acpi_operand_object of type def_field and
409  *              connect it to the parent Node.
410  *
411  ******************************************************************************/
412
413 acpi_status acpi_ex_prep_field_value(struct acpi_create_field_info *info)
414 {
415         union acpi_operand_object *obj_desc;
416         union acpi_operand_object *second_desc = NULL;
417         u32 type;
418         acpi_status status;
419
420         ACPI_FUNCTION_TRACE(ex_prep_field_value);
421
422         /* Parameter validation */
423
424         if (info->field_type != ACPI_TYPE_LOCAL_INDEX_FIELD) {
425                 if (!info->region_node) {
426                         ACPI_ERROR((AE_INFO, "Null RegionNode"));
427                         return_ACPI_STATUS(AE_AML_NO_OPERAND);
428                 }
429
430                 type = acpi_ns_get_type(info->region_node);
431                 if (type != ACPI_TYPE_REGION) {
432                         ACPI_ERROR((AE_INFO,
433                                     "Needed Region, found type %X (%s)",
434                                     type, acpi_ut_get_type_name(type)));
435
436                         return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
437                 }
438         }
439
440         /* Allocate a new field object */
441
442         obj_desc = acpi_ut_create_internal_object(info->field_type);
443         if (!obj_desc) {
444                 return_ACPI_STATUS(AE_NO_MEMORY);
445         }
446
447         /* Initialize areas of the object that are common to all fields */
448
449         obj_desc->common_field.node = info->field_node;
450         status = acpi_ex_prep_common_field_object(obj_desc, info->field_flags,
451                                                   info->attribute,
452                                                   info->field_bit_position,
453                                                   info->field_bit_length);
454         if (ACPI_FAILURE(status)) {
455                 acpi_ut_delete_object_desc(obj_desc);
456                 return_ACPI_STATUS(status);
457         }
458
459         /* Initialize areas of the object that are specific to the field type */
460
461         switch (info->field_type) {
462         case ACPI_TYPE_LOCAL_REGION_FIELD:
463
464                 obj_desc->field.region_obj =
465                     acpi_ns_get_attached_object(info->region_node);
466
467                 /* An additional reference for the container */
468
469                 acpi_ut_add_reference(obj_desc->field.region_obj);
470
471                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
472                                   "RegionField: BitOff %X, Off %X, Gran %X, Region %p\n",
473                                   obj_desc->field.start_field_bit_offset,
474                                   obj_desc->field.base_byte_offset,
475                                   obj_desc->field.access_byte_width,
476                                   obj_desc->field.region_obj));
477                 break;
478
479         case ACPI_TYPE_LOCAL_BANK_FIELD:
480
481                 obj_desc->bank_field.value = info->bank_value;
482                 obj_desc->bank_field.region_obj =
483                     acpi_ns_get_attached_object(info->region_node);
484                 obj_desc->bank_field.bank_obj =
485                     acpi_ns_get_attached_object(info->register_node);
486
487                 /* An additional reference for the attached objects */
488
489                 acpi_ut_add_reference(obj_desc->bank_field.region_obj);
490                 acpi_ut_add_reference(obj_desc->bank_field.bank_obj);
491
492                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
493                                   "Bank Field: BitOff %X, Off %X, Gran %X, Region %p, BankReg %p\n",
494                                   obj_desc->bank_field.start_field_bit_offset,
495                                   obj_desc->bank_field.base_byte_offset,
496                                   obj_desc->field.access_byte_width,
497                                   obj_desc->bank_field.region_obj,
498                                   obj_desc->bank_field.bank_obj));
499
500                 /*
501                  * Remember location in AML stream of the field unit
502                  * opcode and operands -- since the bank_value
503                  * operands must be evaluated.
504                  */
505                 second_desc = obj_desc->common.next_object;
506                 second_desc->extra.aml_start =
507                     ACPI_CAST_PTR(union acpi_parse_object,
508                                   info->data_register_node)->named.data;
509                 second_desc->extra.aml_length =
510                     ACPI_CAST_PTR(union acpi_parse_object,
511                                   info->data_register_node)->named.length;
512
513                 break;
514
515         case ACPI_TYPE_LOCAL_INDEX_FIELD:
516
517                 /* Get the Index and Data registers */
518
519                 obj_desc->index_field.index_obj =
520                     acpi_ns_get_attached_object(info->register_node);
521                 obj_desc->index_field.data_obj =
522                     acpi_ns_get_attached_object(info->data_register_node);
523
524                 if (!obj_desc->index_field.data_obj
525                     || !obj_desc->index_field.index_obj) {
526                         ACPI_ERROR((AE_INFO,
527                                     "Null Index Object during field prep"));
528                         acpi_ut_delete_object_desc(obj_desc);
529                         return_ACPI_STATUS(AE_AML_INTERNAL);
530                 }
531
532                 /* An additional reference for the attached objects */
533
534                 acpi_ut_add_reference(obj_desc->index_field.data_obj);
535                 acpi_ut_add_reference(obj_desc->index_field.index_obj);
536
537                 /*
538                  * April 2006: Changed to match MS behavior
539                  *
540                  * The value written to the Index register is the byte offset of the
541                  * target field in units of the granularity of the index_field
542                  *
543                  * Previously, the value was calculated as an index in terms of the
544                  * width of the Data register, as below:
545                  *
546                  *      obj_desc->index_field.Value = (u32)
547                  *          (Info->field_bit_position / ACPI_MUL_8 (
548                  *              obj_desc->Field.access_byte_width));
549                  *
550                  * February 2006: Tried value as a byte offset:
551                  *      obj_desc->index_field.Value = (u32)
552                  *          ACPI_DIV_8 (Info->field_bit_position);
553                  */
554                 obj_desc->index_field.value =
555                     (u32) ACPI_ROUND_DOWN(ACPI_DIV_8(info->field_bit_position),
556                                           obj_desc->index_field.
557                                           access_byte_width);
558
559                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
560                                   "IndexField: BitOff %X, Off %X, Value %X, Gran %X, Index %p, Data %p\n",
561                                   obj_desc->index_field.start_field_bit_offset,
562                                   obj_desc->index_field.base_byte_offset,
563                                   obj_desc->index_field.value,
564                                   obj_desc->field.access_byte_width,
565                                   obj_desc->index_field.index_obj,
566                                   obj_desc->index_field.data_obj));
567                 break;
568
569         default:
570                 /* No other types should get here */
571                 break;
572         }
573
574         /*
575          * Store the constructed descriptor (obj_desc) into the parent Node,
576          * preserving the current type of that named_obj.
577          */
578         status = acpi_ns_attach_object(info->field_node, obj_desc,
579                                        acpi_ns_get_type(info->field_node));
580
581         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
582                           "Set NamedObj %p [%4.4s], ObjDesc %p\n",
583                           info->field_node,
584                           acpi_ut_get_node_name(info->field_node), obj_desc));
585
586         /* Remove local reference to the object */
587
588         acpi_ut_remove_reference(obj_desc);
589         return_ACPI_STATUS(status);
590 }