git.oblomov.eu Git - linux-2.6/blob - drivers/acpi/executer/exfldio.c

   1 /******************************************************************************
   2  *
   3  * Module Name: exfldio - Aml Field I/O
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2008, Intel Corp.
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions, and the following disclaimer,
  16  *    without modification.
  17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  18  *    substantially similar to the "NO WARRANTY" disclaimer below
  19  *    ("Disclaimer") and any redistribution must be conditioned upon
  20  *    including a substantially similar Disclaimer requirement for further
  21  *    binary redistribution.
  22  * 3. Neither the names of the above-listed copyright holders nor the names
  23  *    of any contributors may be used to endorse or promote products derived
  24  *    from this software without specific prior written permission.
  25  *
  26  * Alternatively, this software may be distributed under the terms of the
  27  * GNU General Public License ("GPL") version 2 as published by the Free
  28  * Software Foundation.
  29  *
  30  * NO WARRANTY
  31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  41  * POSSIBILITY OF SUCH DAMAGES.
  42  */
  43
  44 #include <acpi/acpi.h>
  45 #include <acpi/acinterp.h>
  46 #include <acpi/amlcode.h>
  47 #include <acpi/acevents.h>
  48 #include <acpi/acdispat.h>
  49
  50 #define _COMPONENT          ACPI_EXECUTER
  51 ACPI_MODULE_NAME("exfldio")
  52
  53 /* Local prototypes */
  54 static acpi_status
  55 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
  56                        u32 field_datum_byte_offset,
  57                        acpi_integer * value, u32 read_write);
  58
  59 static u8
  60 acpi_ex_register_overflow(union acpi_operand_object *obj_desc,
  61                           acpi_integer value);
  62
  63 static acpi_status
  64 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
  65                      u32 field_datum_byte_offset);
  66
  67 /*******************************************************************************
  68  *
  69  * FUNCTION:    acpi_ex_setup_region
  70  *
  71  * PARAMETERS:  obj_desc                - Field to be read or written
  72  *              field_datum_byte_offset - Byte offset of this datum within the
  73  *                                        parent field
  74  *
  75  * RETURN:      Status
  76  *
  77  * DESCRIPTION: Common processing for acpi_ex_extract_from_field and
  78  *              acpi_ex_insert_into_field. Initialize the Region if necessary and
  79  *              validate the request.
  80  *
  81  ******************************************************************************/
  82
  83 static acpi_status
  84 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
  85                      u32 field_datum_byte_offset)
  86 {
  87         acpi_status status = AE_OK;
  88         union acpi_operand_object *rgn_desc;
  89
  90         ACPI_FUNCTION_TRACE_U32(ex_setup_region, field_datum_byte_offset);
  91
  92         rgn_desc = obj_desc->common_field.region_obj;
  93
  94         /* We must have a valid region */
  95
  96         if (ACPI_GET_OBJECT_TYPE(rgn_desc) != ACPI_TYPE_REGION) {
  97                 ACPI_ERROR((AE_INFO, "Needed Region, found type %X (%s)",
  98                             ACPI_GET_OBJECT_TYPE(rgn_desc),
  99                             acpi_ut_get_object_type_name(rgn_desc)));
 100
 101                 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
 102         }
 103
 104         /*
 105          * If the Region Address and Length have not been previously evaluated,
 106          * evaluate them now and save the results.
 107          */
 108         if (!(rgn_desc->common.flags & AOPOBJ_DATA_VALID)) {
 109                 status = acpi_ds_get_region_arguments(rgn_desc);
 110                 if (ACPI_FAILURE(status)) {
 111                         return_ACPI_STATUS(status);
 112                 }
 113         }
 114
 115         /* Exit if Address/Length have been disallowed by the host OS */
 116
 117         if (rgn_desc->common.flags & AOPOBJ_INVALID) {
 118                 return_ACPI_STATUS(AE_AML_ILLEGAL_ADDRESS);
 119         }
 120
 121         /*
 122          * Exit now for SMBus address space, it has a non-linear address space
 123          * and the request cannot be directly validated
 124          */
 125         if (rgn_desc->region.space_id == ACPI_ADR_SPACE_SMBUS) {
 126
 127                 /* SMBus has a non-linear address space */
 128
 129                 return_ACPI_STATUS(AE_OK);
 130         }
 131 #ifdef ACPI_UNDER_DEVELOPMENT
 132         /*
 133          * If the Field access is any_acc, we can now compute the optimal
 134          * access (because we know know the length of the parent region)
 135          */
 136         if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 137                 if (ACPI_FAILURE(status)) {
 138                         return_ACPI_STATUS(status);
 139                 }
 140         }
 141 #endif
 142
 143         /*
 144          * Validate the request.  The entire request from the byte offset for a
 145          * length of one field datum (access width) must fit within the region.
 146          * (Region length is specified in bytes)
 147          */
 148         if (rgn_desc->region.length <
 149             (obj_desc->common_field.base_byte_offset +
 150              field_datum_byte_offset +
 151              obj_desc->common_field.access_byte_width)) {
 152                 if (acpi_gbl_enable_interpreter_slack) {
 153                         /*
 154                          * Slack mode only:  We will go ahead and allow access to this
 155                          * field if it is within the region length rounded up to the next
 156                          * access width boundary.
 157                          */
 158                         if (ACPI_ROUND_UP(rgn_desc->region.length,
 159                                           obj_desc->common_field.
 160                                           access_byte_width) >=
 161                             (obj_desc->common_field.base_byte_offset +
 162                              (acpi_native_uint) obj_desc->common_field.
 163                              access_byte_width + field_datum_byte_offset)) {
 164                                 return_ACPI_STATUS(AE_OK);
 165                         }
 166                 }
 167
 168                 if (rgn_desc->region.length <
 169                     obj_desc->common_field.access_byte_width) {
 170                         /*
 171                          * This is the case where the access_type (acc_word, etc.) is wider
 172                          * than the region itself.  For example, a region of length one
 173                          * byte, and a field with Dword access specified.
 174                          */
 175                         ACPI_ERROR((AE_INFO,
 176                                     "Field [%4.4s] access width (%d bytes) too large for region [%4.4s] (length %X)",
 177                                     acpi_ut_get_node_name(obj_desc->
 178                                                           common_field.node),
 179                                     obj_desc->common_field.access_byte_width,
 180                                     acpi_ut_get_node_name(rgn_desc->region.
 181                                                           node),
 182                                     rgn_desc->region.length));
 183                 }
 184
 185                 /*
 186                  * Offset rounded up to next multiple of field width
 187                  * exceeds region length, indicate an error
 188                  */
 189                 ACPI_ERROR((AE_INFO,
 190                             "Field [%4.4s] Base+Offset+Width %X+%X+%X is beyond end of region [%4.4s] (length %X)",
 191                             acpi_ut_get_node_name(obj_desc->common_field.node),
 192                             obj_desc->common_field.base_byte_offset,
 193                             field_datum_byte_offset,
 194                             obj_desc->common_field.access_byte_width,
 195                             acpi_ut_get_node_name(rgn_desc->region.node),
 196                             rgn_desc->region.length));
 197
 198                 return_ACPI_STATUS(AE_AML_REGION_LIMIT);
 199         }
 200
 201         return_ACPI_STATUS(AE_OK);
 202 }
 203
 204 /*******************************************************************************
 205  *
 206  * FUNCTION:    acpi_ex_access_region
 207  *
 208  * PARAMETERS:  obj_desc                - Field to be read
 209  *              field_datum_byte_offset - Byte offset of this datum within the
 210  *                                        parent field
 211  *              Value                   - Where to store value (must at least
 212  *                                        the size of acpi_integer)
 213  *              Function                - Read or Write flag plus other region-
 214  *                                        dependent flags
 215  *
 216  * RETURN:      Status
 217  *
 218  * DESCRIPTION: Read or Write a single field datum to an Operation Region.
 219  *
 220  ******************************************************************************/
 221
 222 acpi_status
 223 acpi_ex_access_region(union acpi_operand_object *obj_desc,
 224                       u32 field_datum_byte_offset,
 225                       acpi_integer * value, u32 function)
 226 {
 227         acpi_status status;
 228         union acpi_operand_object *rgn_desc;
 229         acpi_physical_address address;
 230
 231         ACPI_FUNCTION_TRACE(ex_access_region);
 232
 233         /*
 234          * Ensure that the region operands are fully evaluated and verify
 235          * the validity of the request
 236          */
 237         status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset);
 238         if (ACPI_FAILURE(status)) {
 239                 return_ACPI_STATUS(status);
 240         }
 241
 242         /*
 243          * The physical address of this field datum is:
 244          *
 245          * 1) The base of the region, plus
 246          * 2) The base offset of the field, plus
 247          * 3) The current offset into the field
 248          */
 249         rgn_desc = obj_desc->common_field.region_obj;
 250         address = rgn_desc->region.address +
 251             obj_desc->common_field.base_byte_offset + field_datum_byte_offset;
 252
 253         if ((function & ACPI_IO_MASK) == ACPI_READ) {
 254                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
 255         } else {
 256                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
 257         }
 258
 259         ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
 260                               " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n",
 261                               acpi_ut_get_region_name(rgn_desc->region.
 262                                                       space_id),
 263                               rgn_desc->region.space_id,
 264                               obj_desc->common_field.access_byte_width,
 265                               obj_desc->common_field.base_byte_offset,
 266                               field_datum_byte_offset, ACPI_CAST_PTR(void,
 267                                                                      address)));
 268
 269         /* Invoke the appropriate address_space/op_region handler */
 270
 271         status = acpi_ev_address_space_dispatch(rgn_desc, function,
 272                                                 address,
 273                                                 ACPI_MUL_8(obj_desc->
 274                                                            common_field.
 275                                                            access_byte_width),
 276                                                 value);
 277
 278         if (ACPI_FAILURE(status)) {
 279                 if (status == AE_NOT_IMPLEMENTED) {
 280                         ACPI_ERROR((AE_INFO,
 281                                     "Region %s(%X) not implemented",
 282                                     acpi_ut_get_region_name(rgn_desc->region.
 283                                                             space_id),
 284                                     rgn_desc->region.space_id));
 285                 } else if (status == AE_NOT_EXIST) {
 286                         ACPI_ERROR((AE_INFO,
 287                                     "Region %s(%X) has no handler",
 288                                     acpi_ut_get_region_name(rgn_desc->region.
 289                                                             space_id),
 290                                     rgn_desc->region.space_id));
 291                 }
 292         }
 293
 294         return_ACPI_STATUS(status);
 295 }
 296
 297 /*******************************************************************************
 298  *
 299  * FUNCTION:    acpi_ex_register_overflow
 300  *
 301  * PARAMETERS:  obj_desc                - Register(Field) to be written
 302  *              Value                   - Value to be stored
 303  *
 304  * RETURN:      TRUE if value overflows the field, FALSE otherwise
 305  *
 306  * DESCRIPTION: Check if a value is out of range of the field being written.
 307  *              Used to check if the values written to Index and Bank registers
 308  *              are out of range.  Normally, the value is simply truncated
 309  *              to fit the field, but this case is most likely a serious
 310  *              coding error in the ASL.
 311  *
 312  ******************************************************************************/
 313
 314 static u8
 315 acpi_ex_register_overflow(union acpi_operand_object *obj_desc,
 316                           acpi_integer value)
 317 {
 318
 319         if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
 320                 /*
 321                  * The field is large enough to hold the maximum integer, so we can
 322                  * never overflow it.
 323                  */
 324                 return (FALSE);
 325         }
 326
 327         if (value >= ((acpi_integer) 1 << obj_desc->common_field.bit_length)) {
 328                 /*
 329                  * The Value is larger than the maximum value that can fit into
 330                  * the register.
 331                  */
 332                 return (TRUE);
 333         }
 334
 335         /* The Value will fit into the field with no truncation */
 336
 337         return (FALSE);
 338 }
 339
 340 /*******************************************************************************
 341  *
 342  * FUNCTION:    acpi_ex_field_datum_io
 343  *
 344  * PARAMETERS:  obj_desc                - Field to be read
 345  *              field_datum_byte_offset - Byte offset of this datum within the
 346  *                                        parent field
 347  *              Value                   - Where to store value (must be 64 bits)
 348  *              read_write              - Read or Write flag
 349  *
 350  * RETURN:      Status
 351  *
 352  * DESCRIPTION: Read or Write a single datum of a field.  The field_type is
 353  *              demultiplexed here to handle the different types of fields
 354  *              (buffer_field, region_field, index_field, bank_field)
 355  *
 356  ******************************************************************************/
 357
 358 static acpi_status
 359 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
 360                        u32 field_datum_byte_offset,
 361                        acpi_integer * value, u32 read_write)
 362 {
 363         acpi_status status;
 364         acpi_integer local_value;
 365
 366         ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
 367
 368         if (read_write == ACPI_READ) {
 369                 if (!value) {
 370                         local_value = 0;
 371
 372                         /* To support reads without saving return value */
 373                         value = &local_value;
 374                 }
 375
 376                 /* Clear the entire return buffer first, [Very Important!] */
 377
 378                 *value = 0;
 379         }
 380
 381         /*
 382          * The four types of fields are:
 383          *
 384          * buffer_field - Read/write from/to a Buffer
 385          * region_field - Read/write from/to a Operation Region.
 386          * bank_field  - Write to a Bank Register, then read/write from/to an
 387          *               operation_region
 388          * index_field - Write to an Index Register, then read/write from/to a
 389          *               Data Register
 390          */
 391         switch (ACPI_GET_OBJECT_TYPE(obj_desc)) {
 392         case ACPI_TYPE_BUFFER_FIELD:
 393                 /*
 394                  * If the buffer_field arguments have not been previously evaluated,
 395                  * evaluate them now and save the results.
 396                  */
 397                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 398                         status = acpi_ds_get_buffer_field_arguments(obj_desc);
 399                         if (ACPI_FAILURE(status)) {
 400                                 return_ACPI_STATUS(status);
 401                         }
 402                 }
 403
 404                 if (read_write == ACPI_READ) {
 405                         /*
 406                          * Copy the data from the source buffer.
 407                          * Length is the field width in bytes.
 408                          */
 409                         ACPI_MEMCPY(value,
 410                                     (obj_desc->buffer_field.buffer_obj)->buffer.
 411                                     pointer +
 412                                     obj_desc->buffer_field.base_byte_offset +
 413                                     field_datum_byte_offset,
 414                                     obj_desc->common_field.access_byte_width);
 415                 } else {
 416                         /*
 417                          * Copy the data to the target buffer.
 418                          * Length is the field width in bytes.
 419                          */
 420                         ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer.
 421                                     pointer +
 422                                     obj_desc->buffer_field.base_byte_offset +
 423                                     field_datum_byte_offset, value,
 424                                     obj_desc->common_field.access_byte_width);
 425                 }
 426
 427                 status = AE_OK;
 428                 break;
 429
 430         case ACPI_TYPE_LOCAL_BANK_FIELD:
 431
 432                 /*
 433                  * Ensure that the bank_value is not beyond the capacity of
 434                  * the register
 435                  */
 436                 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
 437                                               (acpi_integer) obj_desc->
 438                                               bank_field.value)) {
 439                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
 440                 }
 441
 442                 /*
 443                  * For bank_fields, we must write the bank_value to the bank_register
 444                  * (itself a region_field) before we can access the data.
 445                  */
 446                 status =
 447                     acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
 448                                               &obj_desc->bank_field.value,
 449                                               sizeof(obj_desc->bank_field.
 450                                                      value));
 451                 if (ACPI_FAILURE(status)) {
 452                         return_ACPI_STATUS(status);
 453                 }
 454
 455                 /*
 456                  * Now that the Bank has been selected, fall through to the
 457                  * region_field case and write the datum to the Operation Region
 458                  */
 459
 460                 /*lint -fallthrough */
 461
 462         case ACPI_TYPE_LOCAL_REGION_FIELD:
 463                 /*
 464                  * For simple region_fields, we just directly access the owning
 465                  * Operation Region.
 466                  */
 467                 status =
 468                     acpi_ex_access_region(obj_desc, field_datum_byte_offset,
 469                                           value, read_write);
 470                 break;
 471
 472         case ACPI_TYPE_LOCAL_INDEX_FIELD:
 473
 474                 /*
 475                  * Ensure that the index_value is not beyond the capacity of
 476                  * the register
 477                  */
 478                 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
 479                                               (acpi_integer) obj_desc->
 480                                               index_field.value)) {
 481                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
 482                 }
 483
 484                 /* Write the index value to the index_register (itself a region_field) */
 485
 486                 field_datum_byte_offset += obj_desc->index_field.value;
 487
 488                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 489                                   "Write to Index Register: Value %8.8X\n",
 490                                   field_datum_byte_offset));
 491
 492                 status =
 493                     acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
 494                                               &field_datum_byte_offset,
 495                                               sizeof(field_datum_byte_offset));
 496                 if (ACPI_FAILURE(status)) {
 497                         return_ACPI_STATUS(status);
 498                 }
 499
 500                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 501                                   "I/O to Data Register: ValuePtr %p\n",
 502                                   value));
 503
 504                 if (read_write == ACPI_READ) {
 505
 506                         /* Read the datum from the data_register */
 507
 508                         status =
 509                             acpi_ex_extract_from_field(obj_desc->index_field.
 510                                                        data_obj, value,
 511                                                        sizeof(acpi_integer));
 512                 } else {
 513                         /* Write the datum to the data_register */
 514
 515                         status =
 516                             acpi_ex_insert_into_field(obj_desc->index_field.
 517                                                       data_obj, value,
 518                                                       sizeof(acpi_integer));
 519                 }
 520                 break;
 521
 522         default:
 523
 524                 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %X",
 525                             ACPI_GET_OBJECT_TYPE(obj_desc)));
 526                 status = AE_AML_INTERNAL;
 527                 break;
 528         }
 529
 530         if (ACPI_SUCCESS(status)) {
 531                 if (read_write == ACPI_READ) {
 532                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 533                                           "Value Read %8.8X%8.8X, Width %d\n",
 534                                           ACPI_FORMAT_UINT64(*value),
 535                                           obj_desc->common_field.
 536                                           access_byte_width));
 537                 } else {
 538                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 539                                           "Value Written %8.8X%8.8X, Width %d\n",
 540                                           ACPI_FORMAT_UINT64(*value),
 541                                           obj_desc->common_field.
 542                                           access_byte_width));
 543                 }
 544         }
 545
 546         return_ACPI_STATUS(status);
 547 }
 548
 549 /*******************************************************************************
 550  *
 551  * FUNCTION:    acpi_ex_write_with_update_rule
 552  *
 553  * PARAMETERS:  obj_desc                - Field to be written
 554  *              Mask                    - bitmask within field datum
 555  *              field_value             - Value to write
 556  *              field_datum_byte_offset - Offset of datum within field
 557  *
 558  * RETURN:      Status
 559  *
 560  * DESCRIPTION: Apply the field update rule to a field write
 561  *
 562  ******************************************************************************/
 563
 564 acpi_status
 565 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc,
 566                                acpi_integer mask,
 567                                acpi_integer field_value,
 568                                u32 field_datum_byte_offset)
 569 {
 570         acpi_status status = AE_OK;
 571         acpi_integer merged_value;
 572         acpi_integer current_value;
 573
 574         ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask);
 575
 576         /* Start with the new bits  */
 577
 578         merged_value = field_value;
 579
 580         /* If the mask is all ones, we don't need to worry about the update rule */
 581
 582         if (mask != ACPI_INTEGER_MAX) {
 583
 584                 /* Decode the update rule */
 585
 586                 switch (obj_desc->common_field.
 587                         field_flags & AML_FIELD_UPDATE_RULE_MASK) {
 588                 case AML_FIELD_UPDATE_PRESERVE:
 589                         /*
 590                          * Check if update rule needs to be applied (not if mask is all
 591                          * ones)  The left shift drops the bits we want to ignore.
 592                          */
 593                         if ((~mask << (ACPI_MUL_8(sizeof(mask)) -
 594                                        ACPI_MUL_8(obj_desc->common_field.
 595                                                   access_byte_width))) != 0) {
 596                                 /*
 597                                  * Read the current contents of the byte/word/dword containing
 598                                  * the field, and merge with the new field value.
 599                                  */
 600                                 status =
 601                                     acpi_ex_field_datum_io(obj_desc,
 602                                                            field_datum_byte_offset,
 603                                                            &current_value,
 604                                                            ACPI_READ);
 605                                 if (ACPI_FAILURE(status)) {
 606                                         return_ACPI_STATUS(status);
 607                                 }
 608
 609                                 merged_value |= (current_value & ~mask);
 610                         }
 611                         break;
 612
 613                 case AML_FIELD_UPDATE_WRITE_AS_ONES:
 614
 615                         /* Set positions outside the field to all ones */
 616
 617                         merged_value |= ~mask;
 618                         break;
 619
 620                 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
 621
 622                         /* Set positions outside the field to all zeros */
 623
 624                         merged_value &= mask;
 625                         break;
 626
 627                 default:
 628
 629                         ACPI_ERROR((AE_INFO,
 630                                     "Unknown UpdateRule value: %X",
 631                                     (obj_desc->common_field.
 632                                      field_flags &
 633                                      AML_FIELD_UPDATE_RULE_MASK)));
 634                         return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
 635                 }
 636         }
 637
 638         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 639                           "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
 640                           ACPI_FORMAT_UINT64(mask),
 641                           field_datum_byte_offset,
 642                           obj_desc->common_field.access_byte_width,
 643                           ACPI_FORMAT_UINT64(field_value),
 644                           ACPI_FORMAT_UINT64(merged_value)));
 645
 646         /* Write the merged value */
 647
 648         status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset,
 649                                         &merged_value, ACPI_WRITE);
 650
 651         return_ACPI_STATUS(status);
 652 }
 653
 654 /*******************************************************************************
 655  *
 656  * FUNCTION:    acpi_ex_extract_from_field
 657  *
 658  * PARAMETERS:  obj_desc            - Field to be read
 659  *              Buffer              - Where to store the field data
 660  *              buffer_length       - Length of Buffer
 661  *
 662  * RETURN:      Status
 663  *
 664  * DESCRIPTION: Retrieve the current value of the given field
 665  *
 666  ******************************************************************************/
 667
 668 acpi_status
 669 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
 670                            void *buffer, u32 buffer_length)
 671 {
 672         acpi_status status;
 673         acpi_integer raw_datum;
 674         acpi_integer merged_datum;
 675         u32 field_offset = 0;
 676         u32 buffer_offset = 0;
 677         u32 buffer_tail_bits;
 678         u32 datum_count;
 679         u32 field_datum_count;
 680         u32 i;
 681
 682         ACPI_FUNCTION_TRACE(ex_extract_from_field);
 683
 684         /* Validate target buffer and clear it */
 685
 686         if (buffer_length <
 687             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
 688                 ACPI_ERROR((AE_INFO,
 689                             "Field size %X (bits) is too large for buffer (%X)",
 690                             obj_desc->common_field.bit_length, buffer_length));
 691
 692                 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
 693         }
 694         ACPI_MEMSET(buffer, 0, buffer_length);
 695
 696         /* Compute the number of datums (access width data items) */
 697
 698         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
 699                                        obj_desc->common_field.access_bit_width);
 700         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
 701                                              obj_desc->common_field.
 702                                              start_field_bit_offset,
 703                                              obj_desc->common_field.
 704                                              access_bit_width);
 705
 706         /* Priming read from the field */
 707
 708         status =
 709             acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
 710                                    ACPI_READ);
 711         if (ACPI_FAILURE(status)) {
 712                 return_ACPI_STATUS(status);
 713         }
 714         merged_datum =
 715             raw_datum >> obj_desc->common_field.start_field_bit_offset;
 716
 717         /* Read the rest of the field */
 718
 719         for (i = 1; i < field_datum_count; i++) {
 720
 721                 /* Get next input datum from the field */
 722
 723                 field_offset += obj_desc->common_field.access_byte_width;
 724                 status = acpi_ex_field_datum_io(obj_desc, field_offset,
 725                                                 &raw_datum, ACPI_READ);
 726                 if (ACPI_FAILURE(status)) {
 727                         return_ACPI_STATUS(status);
 728                 }
 729
 730                 /*
 731                  * Merge with previous datum if necessary.
 732                  *
 733                  * Note: Before the shift, check if the shift value will be larger than
 734                  * the integer size. If so, there is no need to perform the operation.
 735                  * This avoids the differences in behavior between different compilers
 736                  * concerning shift values larger than the target data width.
 737                  */
 738                 if ((obj_desc->common_field.access_bit_width -
 739                      obj_desc->common_field.start_field_bit_offset) <
 740                     ACPI_INTEGER_BIT_SIZE) {
 741                         merged_datum |=
 742                             raw_datum << (obj_desc->common_field.
 743                                           access_bit_width -
 744                                           obj_desc->common_field.
 745                                           start_field_bit_offset);
 746                 }
 747
 748                 if (i == datum_count) {
 749                         break;
 750                 }
 751
 752                 /* Write merged datum to target buffer */
 753
 754                 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
 755                             ACPI_MIN(obj_desc->common_field.access_byte_width,
 756                                      buffer_length - buffer_offset));
 757
 758                 buffer_offset += obj_desc->common_field.access_byte_width;
 759                 merged_datum =
 760                     raw_datum >> obj_desc->common_field.start_field_bit_offset;
 761         }
 762
 763         /* Mask off any extra bits in the last datum */
 764
 765         buffer_tail_bits = obj_desc->common_field.bit_length %
 766             obj_desc->common_field.access_bit_width;
 767         if (buffer_tail_bits) {
 768                 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
 769         }
 770
 771         /* Write the last datum to the buffer */
 772
 773         ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
 774                     ACPI_MIN(obj_desc->common_field.access_byte_width,
 775                              buffer_length - buffer_offset));
 776
 777         return_ACPI_STATUS(AE_OK);
 778 }
 779
 780 /*******************************************************************************
 781  *
 782  * FUNCTION:    acpi_ex_insert_into_field
 783  *
 784  * PARAMETERS:  obj_desc            - Field to be written
 785  *              Buffer              - Data to be written
 786  *              buffer_length       - Length of Buffer
 787  *
 788  * RETURN:      Status
 789  *
 790  * DESCRIPTION: Store the Buffer contents into the given field
 791  *
 792  ******************************************************************************/
 793
 794 acpi_status
 795 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
 796                           void *buffer, u32 buffer_length)
 797 {
 798         acpi_status status;
 799         acpi_integer mask;
 800         acpi_integer width_mask;
 801         acpi_integer merged_datum;
 802         acpi_integer raw_datum = 0;
 803         u32 field_offset = 0;
 804         u32 buffer_offset = 0;
 805         u32 buffer_tail_bits;
 806         u32 datum_count;
 807         u32 field_datum_count;
 808         u32 i;
 809         u32 required_length;
 810         void *new_buffer;
 811
 812         ACPI_FUNCTION_TRACE(ex_insert_into_field);
 813
 814         /* Validate input buffer */
 815
 816         new_buffer = NULL;
 817         required_length =
 818             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
 819         /*
 820          * We must have a buffer that is at least as long as the field
 821          * we are writing to.  This is because individual fields are
 822          * indivisible and partial writes are not supported -- as per
 823          * the ACPI specification.
 824          */
 825         if (buffer_length < required_length) {
 826
 827                 /* We need to create a new buffer */
 828
 829                 new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
 830                 if (!new_buffer) {
 831                         return_ACPI_STATUS(AE_NO_MEMORY);
 832                 }
 833
 834                 /*
 835                  * Copy the original data to the new buffer, starting
 836                  * at Byte zero.  All unused (upper) bytes of the
 837                  * buffer will be 0.
 838                  */
 839                 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length);
 840                 buffer = new_buffer;
 841                 buffer_length = required_length;
 842         }
 843
 844         /*
 845          * Create the bitmasks used for bit insertion.
 846          * Note: This if/else is used to bypass compiler differences with the
 847          * shift operator
 848          */
 849         if (obj_desc->common_field.access_bit_width == ACPI_INTEGER_BIT_SIZE) {
 850                 width_mask = ACPI_INTEGER_MAX;
 851         } else {
 852                 width_mask =
 853                     ACPI_MASK_BITS_ABOVE(obj_desc->common_field.
 854                                          access_bit_width);
 855         }
 856
 857         mask = width_mask &
 858             ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
 859
 860         /* Compute the number of datums (access width data items) */
 861
 862         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
 863                                        obj_desc->common_field.access_bit_width);
 864
 865         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
 866                                              obj_desc->common_field.
 867                                              start_field_bit_offset,
 868                                              obj_desc->common_field.
 869                                              access_bit_width);
 870
 871         /* Get initial Datum from the input buffer */
 872
 873         ACPI_MEMCPY(&raw_datum, buffer,
 874                     ACPI_MIN(obj_desc->common_field.access_byte_width,
 875                              buffer_length - buffer_offset));
 876
 877         merged_datum =
 878             raw_datum << obj_desc->common_field.start_field_bit_offset;
 879
 880         /* Write the entire field */
 881
 882         for (i = 1; i < field_datum_count; i++) {
 883
 884                 /* Write merged datum to the target field */
 885
 886                 merged_datum &= mask;
 887                 status = acpi_ex_write_with_update_rule(obj_desc, mask,
 888                                                         merged_datum,
 889                                                         field_offset);
 890                 if (ACPI_FAILURE(status)) {
 891                         goto exit;
 892                 }
 893
 894                 field_offset += obj_desc->common_field.access_byte_width;
 895
 896                 /*
 897                  * Start new output datum by merging with previous input datum
 898                  * if necessary.
 899                  *
 900                  * Note: Before the shift, check if the shift value will be larger than
 901                  * the integer size. If so, there is no need to perform the operation.
 902                  * This avoids the differences in behavior between different compilers
 903                  * concerning shift values larger than the target data width.
 904                  */
 905                 if ((obj_desc->common_field.access_bit_width -
 906                      obj_desc->common_field.start_field_bit_offset) <
 907                     ACPI_INTEGER_BIT_SIZE) {
 908                         merged_datum =
 909                             raw_datum >> (obj_desc->common_field.
 910                                           access_bit_width -
 911                                           obj_desc->common_field.
 912                                           start_field_bit_offset);
 913                 } else {
 914                         merged_datum = 0;
 915                 }
 916
 917                 mask = width_mask;
 918
 919                 if (i == datum_count) {
 920                         break;
 921                 }
 922
 923                 /* Get the next input datum from the buffer */
 924
 925                 buffer_offset += obj_desc->common_field.access_byte_width;
 926                 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset,
 927                             ACPI_MIN(obj_desc->common_field.access_byte_width,
 928                                      buffer_length - buffer_offset));
 929                 merged_datum |=
 930                     raw_datum << obj_desc->common_field.start_field_bit_offset;
 931         }
 932
 933         /* Mask off any extra bits in the last datum */
 934
 935         buffer_tail_bits = (obj_desc->common_field.bit_length +
 936                             obj_desc->common_field.start_field_bit_offset) %
 937             obj_desc->common_field.access_bit_width;
 938         if (buffer_tail_bits) {
 939                 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
 940         }
 941
 942         /* Write the last datum to the field */
 943
 944         merged_datum &= mask;
 945         status = acpi_ex_write_with_update_rule(obj_desc,
 946                                                 mask, merged_datum,
 947                                                 field_offset);
 948
 949       exit:
 950         /* Free temporary buffer if we used one */
 951
 952         if (new_buffer) {
 953                 ACPI_FREE(new_buffer);
 954         }
 955         return_ACPI_STATUS(status);
 956 }