ACPICA: Lindent
[linux-2.6.git] / drivers / acpi / executer / 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 - 2007, R. Byron Moore
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 <acpi/acinterp.h>
47 #include <acpi/amlcode.h>
48 #include <acpi/acnamesp.h>
49
50 #define _COMPONENT          ACPI_EXECUTER
51 ACPI_MODULE_NAME("exprep")
52
53 /* Local prototypes */
54 static u32
55 acpi_ex_decode_field_access(union acpi_operand_object *obj_desc,
56                             u8 field_flags, u32 * return_byte_alignment);
57
58 #ifdef ACPI_UNDER_DEVELOPMENT
59
60 static u32
61 acpi_ex_generate_access(u32 field_bit_offset,
62                         u32 field_bit_length, u32 region_length);
63
64 /*******************************************************************************
65  *
66  * FUNCTION:    acpi_ex_generate_access
67  *
68  * PARAMETERS:  field_bit_offset    - Start of field within parent region/buffer
69  *              field_bit_length    - Length of field in bits
70  *              region_length       - Length of parent in bytes
71  *
72  * RETURN:      Field granularity (8, 16, 32 or 64) and
73  *              byte_alignment (1, 2, 3, or 4)
74  *
75  * DESCRIPTION: Generate an optimal access width for fields defined with the
76  *              any_acc keyword.
77  *
78  * NOTE: Need to have the region_length in order to check for boundary
79  *       conditions (end-of-region).  However, the region_length is a deferred
80  *       operation.  Therefore, to complete this implementation, the generation
81  *       of this access width must be deferred until the region length has
82  *       been evaluated.
83  *
84  ******************************************************************************/
85
86 static u32
87 acpi_ex_generate_access(u32 field_bit_offset,
88                         u32 field_bit_length, u32 region_length)
89 {
90         u32 field_byte_length;
91         u32 field_byte_offset;
92         u32 field_byte_end_offset;
93         u32 access_byte_width;
94         u32 field_start_offset;
95         u32 field_end_offset;
96         u32 minimum_access_width = 0xFFFFFFFF;
97         u32 minimum_accesses = 0xFFFFFFFF;
98         u32 accesses;
99
100         ACPI_FUNCTION_TRACE(ex_generate_access);
101
102         /* Round Field start offset and length to "minimal" byte boundaries */
103
104         field_byte_offset = ACPI_DIV_8(ACPI_ROUND_DOWN(field_bit_offset, 8));
105         field_byte_end_offset = ACPI_DIV_8(ACPI_ROUND_UP(field_bit_length +
106                                                          field_bit_offset, 8));
107         field_byte_length = field_byte_end_offset - field_byte_offset;
108
109         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
110                           "Bit length %d, Bit offset %d\n",
111                           field_bit_length, field_bit_offset));
112
113         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
114                           "Byte Length %d, Byte Offset %d, End Offset %d\n",
115                           field_byte_length, field_byte_offset,
116                           field_byte_end_offset));
117
118         /*
119          * Iterative search for the maximum access width that is both aligned
120          * and does not go beyond the end of the region
121          *
122          * Start at byte_acc and work upwards to qword_acc max. (1,2,4,8 bytes)
123          */
124         for (access_byte_width = 1; access_byte_width <= 8;
125              access_byte_width <<= 1) {
126                 /*
127                  * 1) Round end offset up to next access boundary and make sure that
128                  *    this does not go beyond the end of the parent region.
129                  * 2) When the Access width is greater than the field_byte_length, we
130                  *    are done. (This does not optimize for the perfectly aligned
131                  *    case yet).
132                  */
133                 if (ACPI_ROUND_UP(field_byte_end_offset, access_byte_width) <=
134                     region_length) {
135                         field_start_offset =
136                             ACPI_ROUND_DOWN(field_byte_offset,
137                                             access_byte_width) /
138                             access_byte_width;
139
140                         field_end_offset =
141                             ACPI_ROUND_UP((field_byte_length +
142                                            field_byte_offset),
143                                           access_byte_width) /
144                             access_byte_width;
145
146                         accesses = field_end_offset - field_start_offset;
147
148                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
149                                           "AccessWidth %d end is within region\n",
150                                           access_byte_width));
151
152                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
153                                           "Field Start %d, Field End %d -- requires %d accesses\n",
154                                           field_start_offset, field_end_offset,
155                                           accesses));
156
157                         /* Single access is optimal */
158
159                         if (accesses <= 1) {
160                                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
161                                                   "Entire field can be accessed with one operation of size %d\n",
162                                                   access_byte_width));
163                                 return_VALUE(access_byte_width);
164                         }
165
166                         /*
167                          * Fits in the region, but requires more than one read/write.
168                          * try the next wider access on next iteration
169                          */
170                         if (accesses < minimum_accesses) {
171                                 minimum_accesses = accesses;
172                                 minimum_access_width = access_byte_width;
173                         }
174                 } else {
175                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
176                                           "AccessWidth %d end is NOT within region\n",
177                                           access_byte_width));
178                         if (access_byte_width == 1) {
179                                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
180                                                   "Field goes beyond end-of-region!\n"));
181
182                                 /* Field does not fit in the region at all */
183
184                                 return_VALUE(0);
185                         }
186
187                         /*
188                          * This width goes beyond the end-of-region, back off to
189                          * previous access
190                          */
191                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
192                                           "Backing off to previous optimal access width of %d\n",
193                                           minimum_access_width));
194                         return_VALUE(minimum_access_width);
195                 }
196         }
197
198         /*
199          * Could not read/write field with one operation,
200          * just use max access width
201          */
202         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
203                           "Cannot access field in one operation, using width 8\n"));
204         return_VALUE(8);
205 }
206 #endif                          /* ACPI_UNDER_DEVELOPMENT */
207
208 /*******************************************************************************
209  *
210  * FUNCTION:    acpi_ex_decode_field_access
211  *
212  * PARAMETERS:  obj_desc            - Field object
213  *              field_flags         - Encoded fieldflags (contains access bits)
214  *              return_byte_alignment - Where the byte alignment is returned
215  *
216  * RETURN:      Field granularity (8, 16, 32 or 64) and
217  *              byte_alignment (1, 2, 3, or 4)
218  *
219  * DESCRIPTION: Decode the access_type bits of a field definition.
220  *
221  ******************************************************************************/
222
223 static u32
224 acpi_ex_decode_field_access(union acpi_operand_object *obj_desc,
225                             u8 field_flags, u32 * return_byte_alignment)
226 {
227         u32 access;
228         u32 byte_alignment;
229         u32 bit_length;
230
231         ACPI_FUNCTION_TRACE(ex_decode_field_access);
232
233         access = (field_flags & AML_FIELD_ACCESS_TYPE_MASK);
234
235         switch (access) {
236         case AML_FIELD_ACCESS_ANY:
237
238 #ifdef ACPI_UNDER_DEVELOPMENT
239                 byte_alignment =
240                     acpi_ex_generate_access(obj_desc->common_field.
241                                             start_field_bit_offset,
242                                             obj_desc->common_field.bit_length,
243                                             0xFFFFFFFF
244                                             /* Temp until we pass region_length as parameter */
245                     );
246                 bit_length = byte_alignment * 8;
247 #endif
248
249                 byte_alignment = 1;
250                 bit_length = 8;
251                 break;
252
253         case AML_FIELD_ACCESS_BYTE:
254         case AML_FIELD_ACCESS_BUFFER:   /* ACPI 2.0 (SMBus Buffer) */
255                 byte_alignment = 1;
256                 bit_length = 8;
257                 break;
258
259         case AML_FIELD_ACCESS_WORD:
260                 byte_alignment = 2;
261                 bit_length = 16;
262                 break;
263
264         case AML_FIELD_ACCESS_DWORD:
265                 byte_alignment = 4;
266                 bit_length = 32;
267                 break;
268
269         case AML_FIELD_ACCESS_QWORD:    /* ACPI 2.0 */
270                 byte_alignment = 8;
271                 bit_length = 64;
272                 break;
273
274         default:
275                 /* Invalid field access type */
276
277                 ACPI_ERROR((AE_INFO, "Unknown field access type %X", access));
278                 return_UINT32(0);
279         }
280
281         if (ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_BUFFER_FIELD) {
282                 /*
283                  * buffer_field access can be on any byte boundary, so the
284                  * byte_alignment is always 1 byte -- regardless of any byte_alignment
285                  * implied by the field access type.
286                  */
287                 byte_alignment = 1;
288         }
289
290         *return_byte_alignment = byte_alignment;
291         return_UINT32(bit_length);
292 }
293
294 /*******************************************************************************
295  *
296  * FUNCTION:    acpi_ex_prep_common_field_object
297  *
298  * PARAMETERS:  obj_desc            - The field object
299  *              field_flags         - Access, lock_rule, and update_rule.
300  *                                    The format of a field_flag is described
301  *                                    in the ACPI specification
302  *              field_attribute     - Special attributes (not used)
303  *              field_bit_position  - Field start position
304  *              field_bit_length    - Field length in number of bits
305  *
306  * RETURN:      Status
307  *
308  * DESCRIPTION: Initialize the areas of the field object that are common
309  *              to the various types of fields.  Note: This is very "sensitive"
310  *              code because we are solving the general case for field
311  *              alignment.
312  *
313  ******************************************************************************/
314
315 acpi_status
316 acpi_ex_prep_common_field_object(union acpi_operand_object *obj_desc,
317                                  u8 field_flags,
318                                  u8 field_attribute,
319                                  u32 field_bit_position, u32 field_bit_length)
320 {
321         u32 access_bit_width;
322         u32 byte_alignment;
323         u32 nearest_byte_address;
324
325         ACPI_FUNCTION_TRACE(ex_prep_common_field_object);
326
327         /*
328          * Note: the structure being initialized is the
329          * ACPI_COMMON_FIELD_INFO;  No structure fields outside of the common
330          * area are initialized by this procedure.
331          */
332         obj_desc->common_field.field_flags = field_flags;
333         obj_desc->common_field.attribute = field_attribute;
334         obj_desc->common_field.bit_length = field_bit_length;
335
336         /*
337          * Decode the access type so we can compute offsets.  The access type gives
338          * two pieces of information - the width of each field access and the
339          * necessary byte_alignment (address granularity) of the access.
340          *
341          * For any_acc, the access_bit_width is the largest width that is both
342          * necessary and possible in an attempt to access the whole field in one
343          * I/O operation.  However, for any_acc, the byte_alignment is always one
344          * byte.
345          *
346          * For all Buffer Fields, the byte_alignment is always one byte.
347          *
348          * For all other access types (Byte, Word, Dword, Qword), the Bitwidth is
349          * the same (equivalent) as the byte_alignment.
350          */
351         access_bit_width = acpi_ex_decode_field_access(obj_desc, field_flags,
352                                                        &byte_alignment);
353         if (!access_bit_width) {
354                 return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
355         }
356
357         /* Setup width (access granularity) fields */
358
359         obj_desc->common_field.access_byte_width = (u8)
360             ACPI_DIV_8(access_bit_width);       /* 1,  2,  4,  8 */
361
362         obj_desc->common_field.access_bit_width = (u8) access_bit_width;
363
364         /*
365          * base_byte_offset is the address of the start of the field within the
366          * region.  It is the byte address of the first *datum* (field-width data
367          * unit) of the field. (i.e., the first datum that contains at least the
368          * first *bit* of the field.)
369          *
370          * Note: byte_alignment is always either equal to the access_bit_width or 8
371          * (Byte access), and it defines the addressing granularity of the parent
372          * region or buffer.
373          */
374         nearest_byte_address =
375             ACPI_ROUND_BITS_DOWN_TO_BYTES(field_bit_position);
376         obj_desc->common_field.base_byte_offset = (u32)
377             ACPI_ROUND_DOWN(nearest_byte_address, byte_alignment);
378
379         /*
380          * start_field_bit_offset is the offset of the first bit of the field within
381          * a field datum.
382          */
383         obj_desc->common_field.start_field_bit_offset = (u8)
384             (field_bit_position -
385              ACPI_MUL_8(obj_desc->common_field.base_byte_offset));
386
387         /*
388          * Does the entire field fit within a single field access element? (datum)
389          * (i.e., without crossing a datum boundary)
390          */
391         if ((obj_desc->common_field.start_field_bit_offset +
392              field_bit_length) <= (u16) access_bit_width) {
393                 obj_desc->common.flags |= AOPOBJ_SINGLE_DATUM;
394         }
395
396         return_ACPI_STATUS(AE_OK);
397 }
398
399 /*******************************************************************************
400  *
401  * FUNCTION:    acpi_ex_prep_field_value
402  *
403  * PARAMETERS:  Info    - Contains all field creation info
404  *
405  * RETURN:      Status
406  *
407  * DESCRIPTION: Construct an union acpi_operand_object of type def_field and
408  *              connect it to the parent Node.
409  *
410  ******************************************************************************/
411
412 acpi_status acpi_ex_prep_field_value(struct acpi_create_field_info *info)
413 {
414         union acpi_operand_object *obj_desc;
415         u32 type;
416         acpi_status status;
417
418         ACPI_FUNCTION_TRACE(ex_prep_field_value);
419
420         /* Parameter validation */
421
422         if (info->field_type != ACPI_TYPE_LOCAL_INDEX_FIELD) {
423                 if (!info->region_node) {
424                         ACPI_ERROR((AE_INFO, "Null RegionNode"));
425                         return_ACPI_STATUS(AE_AML_NO_OPERAND);
426                 }
427
428                 type = acpi_ns_get_type(info->region_node);
429                 if (type != ACPI_TYPE_REGION) {
430                         ACPI_ERROR((AE_INFO,
431                                     "Needed Region, found type %X (%s)",
432                                     type, acpi_ut_get_type_name(type)));
433
434                         return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
435                 }
436         }
437
438         /* Allocate a new field object */
439
440         obj_desc = acpi_ut_create_internal_object(info->field_type);
441         if (!obj_desc) {
442                 return_ACPI_STATUS(AE_NO_MEMORY);
443         }
444
445         /* Initialize areas of the object that are common to all fields */
446
447         obj_desc->common_field.node = info->field_node;
448         status = acpi_ex_prep_common_field_object(obj_desc, info->field_flags,
449                                                   info->attribute,
450                                                   info->field_bit_position,
451                                                   info->field_bit_length);
452         if (ACPI_FAILURE(status)) {
453                 acpi_ut_delete_object_desc(obj_desc);
454                 return_ACPI_STATUS(status);
455         }
456
457         /* Initialize areas of the object that are specific to the field type */
458
459         switch (info->field_type) {
460         case ACPI_TYPE_LOCAL_REGION_FIELD:
461
462                 obj_desc->field.region_obj =
463                     acpi_ns_get_attached_object(info->region_node);
464
465                 /* An additional reference for the container */
466
467                 acpi_ut_add_reference(obj_desc->field.region_obj);
468
469                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
470                                   "RegionField: BitOff %X, Off %X, Gran %X, Region %p\n",
471                                   obj_desc->field.start_field_bit_offset,
472                                   obj_desc->field.base_byte_offset,
473                                   obj_desc->field.access_byte_width,
474                                   obj_desc->field.region_obj));
475                 break;
476
477         case ACPI_TYPE_LOCAL_BANK_FIELD:
478
479                 obj_desc->bank_field.value = info->bank_value;
480                 obj_desc->bank_field.region_obj =
481                     acpi_ns_get_attached_object(info->region_node);
482                 obj_desc->bank_field.bank_obj =
483                     acpi_ns_get_attached_object(info->register_node);
484
485                 /* An additional reference for the attached objects */
486
487                 acpi_ut_add_reference(obj_desc->bank_field.region_obj);
488                 acpi_ut_add_reference(obj_desc->bank_field.bank_obj);
489
490                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
491                                   "Bank Field: BitOff %X, Off %X, Gran %X, Region %p, BankReg %p\n",
492                                   obj_desc->bank_field.start_field_bit_offset,
493                                   obj_desc->bank_field.base_byte_offset,
494                                   obj_desc->field.access_byte_width,
495                                   obj_desc->bank_field.region_obj,
496                                   obj_desc->bank_field.bank_obj));
497                 break;
498
499         case ACPI_TYPE_LOCAL_INDEX_FIELD:
500
501                 /* Get the Index and Data registers */
502
503                 obj_desc->index_field.index_obj =
504                     acpi_ns_get_attached_object(info->register_node);
505                 obj_desc->index_field.data_obj =
506                     acpi_ns_get_attached_object(info->data_register_node);
507
508                 if (!obj_desc->index_field.data_obj
509                     || !obj_desc->index_field.index_obj) {
510                         ACPI_ERROR((AE_INFO,
511                                     "Null Index Object during field prep"));
512                         acpi_ut_delete_object_desc(obj_desc);
513                         return_ACPI_STATUS(AE_AML_INTERNAL);
514                 }
515
516                 /* An additional reference for the attached objects */
517
518                 acpi_ut_add_reference(obj_desc->index_field.data_obj);
519                 acpi_ut_add_reference(obj_desc->index_field.index_obj);
520
521                 /*
522                  * April 2006: Changed to match MS behavior
523                  *
524                  * The value written to the Index register is the byte offset of the
525                  * target field in units of the granularity of the index_field
526                  *
527                  * Previously, the value was calculated as an index in terms of the
528                  * width of the Data register, as below:
529                  *
530                  *      obj_desc->index_field.Value = (u32)
531                  *          (Info->field_bit_position / ACPI_MUL_8 (
532                  *              obj_desc->Field.access_byte_width));
533                  *
534                  * February 2006: Tried value as a byte offset:
535                  *      obj_desc->index_field.Value = (u32)
536                  *          ACPI_DIV_8 (Info->field_bit_position);
537                  */
538                 obj_desc->index_field.value =
539                     (u32) ACPI_ROUND_DOWN(ACPI_DIV_8(info->field_bit_position),
540                                           obj_desc->index_field.
541                                           access_byte_width);
542
543                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
544                                   "IndexField: BitOff %X, Off %X, Value %X, Gran %X, Index %p, Data %p\n",
545                                   obj_desc->index_field.start_field_bit_offset,
546                                   obj_desc->index_field.base_byte_offset,
547                                   obj_desc->index_field.value,
548                                   obj_desc->field.access_byte_width,
549                                   obj_desc->index_field.index_obj,
550                                   obj_desc->index_field.data_obj));
551                 break;
552
553         default:
554                 /* No other types should get here */
555                 break;
556         }
557
558         /*
559          * Store the constructed descriptor (obj_desc) into the parent Node,
560          * preserving the current type of that named_obj.
561          */
562         status = acpi_ns_attach_object(info->field_node, obj_desc,
563                                        acpi_ns_get_type(info->field_node));
564
565         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
566                           "Set NamedObj %p [%4.4s], ObjDesc %p\n",
567                           info->field_node,
568                           acpi_ut_get_node_name(info->field_node), obj_desc));
569
570         /* Remove local reference to the object */
571
572         acpi_ut_remove_reference(obj_desc);
573         return_ACPI_STATUS(status);
574 }