[ACPI] ACPICA 20050930
[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 - 2005, 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                                           "access_width %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                                           "access_width %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_DEBUG_PRINT((ACPI_DB_ERROR,
278                                   "Unknown field access type %X\n", 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 an 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         u32 type;
417         acpi_status status;
418
419         ACPI_FUNCTION_TRACE("ex_prep_field_value");
420
421         /* Parameter validation */
422
423         if (info->field_type != ACPI_TYPE_LOCAL_INDEX_FIELD) {
424                 if (!info->region_node) {
425                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Null region_node\n"));
426                         return_ACPI_STATUS(AE_AML_NO_OPERAND);
427                 }
428
429                 type = acpi_ns_get_type(info->region_node);
430                 if (type != ACPI_TYPE_REGION) {
431                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
432                                           "Needed Region, found type %X (%s)\n",
433                                           type, acpi_ut_get_type_name(type)));
434
435                         return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
436                 }
437         }
438
439         /* Allocate a new field object */
440
441         obj_desc = acpi_ut_create_internal_object(info->field_type);
442         if (!obj_desc) {
443                 return_ACPI_STATUS(AE_NO_MEMORY);
444         }
445
446         /* Initialize areas of the object that are common to all fields */
447
448         obj_desc->common_field.node = info->field_node;
449         status = acpi_ex_prep_common_field_object(obj_desc, info->field_flags,
450                                                   info->attribute,
451                                                   info->field_bit_position,
452                                                   info->field_bit_length);
453         if (ACPI_FAILURE(status)) {
454                 acpi_ut_delete_object_desc(obj_desc);
455                 return_ACPI_STATUS(status);
456         }
457
458         /* Initialize areas of the object that are specific to the field type */
459
460         switch (info->field_type) {
461         case ACPI_TYPE_LOCAL_REGION_FIELD:
462
463                 obj_desc->field.region_obj =
464                     acpi_ns_get_attached_object(info->region_node);
465
466                 /* An additional reference for the container */
467
468                 acpi_ut_add_reference(obj_desc->field.region_obj);
469
470                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
471                                   "region_field: bit_off %X, Off %X, Gran %X, Region %p\n",
472                                   obj_desc->field.start_field_bit_offset,
473                                   obj_desc->field.base_byte_offset,
474                                   obj_desc->field.access_byte_width,
475                                   obj_desc->field.region_obj));
476                 break;
477
478         case ACPI_TYPE_LOCAL_BANK_FIELD:
479
480                 obj_desc->bank_field.value = info->bank_value;
481                 obj_desc->bank_field.region_obj =
482                     acpi_ns_get_attached_object(info->region_node);
483                 obj_desc->bank_field.bank_obj =
484                     acpi_ns_get_attached_object(info->register_node);
485
486                 /* An additional reference for the attached objects */
487
488                 acpi_ut_add_reference(obj_desc->bank_field.region_obj);
489                 acpi_ut_add_reference(obj_desc->bank_field.bank_obj);
490
491                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
492                                   "Bank Field: bit_off %X, Off %X, Gran %X, Region %p, bank_reg %p\n",
493                                   obj_desc->bank_field.start_field_bit_offset,
494                                   obj_desc->bank_field.base_byte_offset,
495                                   obj_desc->field.access_byte_width,
496                                   obj_desc->bank_field.region_obj,
497                                   obj_desc->bank_field.bank_obj));
498                 break;
499
500         case ACPI_TYPE_LOCAL_INDEX_FIELD:
501
502                 obj_desc->index_field.index_obj =
503                     acpi_ns_get_attached_object(info->register_node);
504                 obj_desc->index_field.data_obj =
505                     acpi_ns_get_attached_object(info->data_register_node);
506                 obj_desc->index_field.value = (u32)
507                     (info->field_bit_position /
508                      ACPI_MUL_8(obj_desc->field.access_byte_width));
509
510                 if (!obj_desc->index_field.data_obj
511                     || !obj_desc->index_field.index_obj) {
512                         ACPI_REPORT_ERROR(("Null Index Object during field prep\n"));
513                         acpi_ut_delete_object_desc(obj_desc);
514                         return_ACPI_STATUS(AE_AML_INTERNAL);
515                 }
516
517                 /* An additional reference for the attached objects */
518
519                 acpi_ut_add_reference(obj_desc->index_field.data_obj);
520                 acpi_ut_add_reference(obj_desc->index_field.index_obj);
521
522                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
523                                   "index_field: bit_off %X, Off %X, Value %X, Gran %X, Index %p, Data %p\n",
524                                   obj_desc->index_field.start_field_bit_offset,
525                                   obj_desc->index_field.base_byte_offset,
526                                   obj_desc->index_field.value,
527                                   obj_desc->field.access_byte_width,
528                                   obj_desc->index_field.index_obj,
529                                   obj_desc->index_field.data_obj));
530                 break;
531
532         default:
533                 /* No other types should get here */
534                 break;
535         }
536
537         /*
538          * Store the constructed descriptor (obj_desc) into the parent Node,
539          * preserving the current type of that named_obj.
540          */
541         status = acpi_ns_attach_object(info->field_node, obj_desc,
542                                        acpi_ns_get_type(info->field_node));
543
544         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
545                           "Set named_obj %p [%4.4s], obj_desc %p\n",
546                           info->field_node,
547                           acpi_ut_get_node_name(info->field_node), obj_desc));
548
549         /* Remove local reference to the object */
550
551         acpi_ut_remove_reference(obj_desc);
552         return_ACPI_STATUS(status);
553 }