git.oblomov.eu Git - linux-2.6/blob - 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 (obj_desc->common.type == 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 }