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 - 2007, R. Byron Moore
   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, (void *)address));
 267
 268         /* Invoke the appropriate address_space/op_region handler */
 269
 270         status = acpi_ev_address_space_dispatch(rgn_desc, function,
 271                                                 address,
 272                                                 ACPI_MUL_8(obj_desc->
 273                                                            common_field.
 274                                                            access_byte_width),
 275                                                 value);
 276
 277         if (ACPI_FAILURE(status)) {
 278                 if (status == AE_NOT_IMPLEMENTED) {
 279                         ACPI_ERROR((AE_INFO,
 280                                     "Region %s(%X) not implemented",
 281                                     acpi_ut_get_region_name(rgn_desc->region.
 282                                                             space_id),
 283                                     rgn_desc->region.space_id));
 284                 } else if (status == AE_NOT_EXIST) {
 285                         ACPI_ERROR((AE_INFO,
 286                                     "Region %s(%X) has no handler",
 287                                     acpi_ut_get_region_name(rgn_desc->region.
 288                                                             space_id),
 289                                     rgn_desc->region.space_id));
 290                 }
 291         }
 292
 293         return_ACPI_STATUS(status);
 294 }
 295
 296 /*******************************************************************************
 297  *
 298  * FUNCTION:    acpi_ex_register_overflow
 299  *
 300  * PARAMETERS:  obj_desc                - Register(Field) to be written
 301  *              Value                   - Value to be stored
 302  *
 303  * RETURN:      TRUE if value overflows the field, FALSE otherwise
 304  *
 305  * DESCRIPTION: Check if a value is out of range of the field being written.
 306  *              Used to check if the values written to Index and Bank registers
 307  *              are out of range.  Normally, the value is simply truncated
 308  *              to fit the field, but this case is most likely a serious
 309  *              coding error in the ASL.
 310  *
 311  ******************************************************************************/
 312
 313 static u8
 314 acpi_ex_register_overflow(union acpi_operand_object *obj_desc,
 315                           acpi_integer value)
 316 {
 317
 318         if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
 319                 /*
 320                  * The field is large enough to hold the maximum integer, so we can
 321                  * never overflow it.
 322                  */
 323                 return (FALSE);
 324         }
 325
 326         if (value >= ((acpi_integer) 1 << obj_desc->common_field.bit_length)) {
 327                 /*
 328                  * The Value is larger than the maximum value that can fit into
 329                  * the register.
 330                  */
 331                 return (TRUE);
 332         }
 333
 334         /* The Value will fit into the field with no truncation */
 335
 336         return (FALSE);
 337 }
 338
 339 /*******************************************************************************
 340  *
 341  * FUNCTION:    acpi_ex_field_datum_io
 342  *
 343  * PARAMETERS:  obj_desc                - Field to be read
 344  *              field_datum_byte_offset - Byte offset of this datum within the
 345  *                                        parent field
 346  *              Value                   - Where to store value (must be 64 bits)
 347  *              read_write              - Read or Write flag
 348  *
 349  * RETURN:      Status
 350  *
 351  * DESCRIPTION: Read or Write a single datum of a field.  The field_type is
 352  *              demultiplexed here to handle the different types of fields
 353  *              (buffer_field, region_field, index_field, bank_field)
 354  *
 355  ******************************************************************************/
 356
 357 static acpi_status
 358 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
 359                        u32 field_datum_byte_offset,
 360                        acpi_integer * value, u32 read_write)
 361 {
 362         acpi_status status;
 363         acpi_integer local_value;
 364
 365         ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
 366
 367         if (read_write == ACPI_READ) {
 368                 if (!value) {
 369                         local_value = 0;
 370
 371                         /* To support reads without saving return value */
 372                         value = &local_value;
 373                 }
 374
 375                 /* Clear the entire return buffer first, [Very Important!] */
 376
 377                 *value = 0;
 378         }
 379
 380         /*
 381          * The four types of fields are:
 382          *
 383          * buffer_field - Read/write from/to a Buffer
 384          * region_field - Read/write from/to a Operation Region.
 385          * bank_field  - Write to a Bank Register, then read/write from/to an
 386          *               operation_region
 387          * index_field - Write to an Index Register, then read/write from/to a
 388          *               Data Register
 389          */
 390         switch (ACPI_GET_OBJECT_TYPE(obj_desc)) {
 391         case ACPI_TYPE_BUFFER_FIELD:
 392                 /*
 393                  * If the buffer_field arguments have not been previously evaluated,
 394                  * evaluate them now and save the results.
 395                  */
 396                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 397                         status = acpi_ds_get_buffer_field_arguments(obj_desc);
 398                         if (ACPI_FAILURE(status)) {
 399                                 return_ACPI_STATUS(status);
 400                         }
 401                 }
 402
 403                 if (read_write == ACPI_READ) {
 404                         /*
 405                          * Copy the data from the source buffer.
 406                          * Length is the field width in bytes.
 407                          */
 408                         ACPI_MEMCPY(value,
 409                                     (obj_desc->buffer_field.buffer_obj)->buffer.
 410                                     pointer +
 411                                     obj_desc->buffer_field.base_byte_offset +
 412                                     field_datum_byte_offset,
 413                                     obj_desc->common_field.access_byte_width);
 414                 } else {
 415                         /*
 416                          * Copy the data to the target buffer.
 417                          * Length is the field width in bytes.
 418                          */
 419                         ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer.
 420                                     pointer +
 421                                     obj_desc->buffer_field.base_byte_offset +
 422                                     field_datum_byte_offset, value,
 423                                     obj_desc->common_field.access_byte_width);
 424                 }
 425
 426                 status = AE_OK;
 427                 break;
 428
 429         case ACPI_TYPE_LOCAL_BANK_FIELD:
 430
 431                 /*
 432                  * Ensure that the bank_value is not beyond the capacity of
 433                  * the register
 434                  */
 435                 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
 436                                               (acpi_integer) obj_desc->
 437                                               bank_field.value)) {
 438                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
 439                 }
 440
 441                 /*
 442                  * For bank_fields, we must write the bank_value to the bank_register
 443                  * (itself a region_field) before we can access the data.
 444                  */
 445                 status =
 446                     acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
 447                                               &obj_desc->bank_field.value,
 448                                               sizeof(obj_desc->bank_field.
 449                                                      value));
 450                 if (ACPI_FAILURE(status)) {
 451                         return_ACPI_STATUS(status);
 452                 }
 453
 454                 /*
 455                  * Now that the Bank has been selected, fall through to the
 456                  * region_field case and write the datum to the Operation Region
 457                  */
 458
 459                 /*lint -fallthrough */
 460
 461         case ACPI_TYPE_LOCAL_REGION_FIELD:
 462                 /*
 463                  * For simple region_fields, we just directly access the owning
 464                  * Operation Region.
 465                  */
 466                 status =
 467                     acpi_ex_access_region(obj_desc, field_datum_byte_offset,
 468                                           value, read_write);
 469                 break;
 470
 471         case ACPI_TYPE_LOCAL_INDEX_FIELD:
 472
 473                 /*
 474                  * Ensure that the index_value is not beyond the capacity of
 475                  * the register
 476                  */
 477                 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
 478                                               (acpi_integer) obj_desc->
 479                                               index_field.value)) {
 480                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
 481                 }
 482
 483                 /* Write the index value to the index_register (itself a region_field) */
 484
 485                 field_datum_byte_offset += obj_desc->index_field.value;
 486
 487                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 488                                   "Write to Index Register: Value %8.8X\n",
 489                                   field_datum_byte_offset));
 490
 491                 status =
 492                     acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
 493                                               &field_datum_byte_offset,
 494                                               sizeof(field_datum_byte_offset));
 495                 if (ACPI_FAILURE(status)) {
 496                         return_ACPI_STATUS(status);
 497                 }
 498
 499                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 500                                   "I/O to Data Register: ValuePtr %p\n",
 501                                   value));
 502
 503                 if (read_write == ACPI_READ) {
 504
 505                         /* Read the datum from the data_register */
 506
 507                         status =
 508                             acpi_ex_extract_from_field(obj_desc->index_field.
 509                                                        data_obj, value,
 510                                                        sizeof(acpi_integer));
 511                 } else {
 512                         /* Write the datum to the data_register */
 513
 514                         status =
 515                             acpi_ex_insert_into_field(obj_desc->index_field.
 516                                                       data_obj, value,
 517                                                       sizeof(acpi_integer));
 518                 }
 519                 break;
 520
 521         default:
 522
 523                 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %X",
 524                             ACPI_GET_OBJECT_TYPE(obj_desc)));
 525                 status = AE_AML_INTERNAL;
 526                 break;
 527         }
 528
 529         if (ACPI_SUCCESS(status)) {
 530                 if (read_write == ACPI_READ) {
 531                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 532                                           "Value Read %8.8X%8.8X, Width %d\n",
 533                                           ACPI_FORMAT_UINT64(*value),
 534                                           obj_desc->common_field.
 535                                           access_byte_width));
 536                 } else {
 537                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 538                                           "Value Written %8.8X%8.8X, Width %d\n",
 539                                           ACPI_FORMAT_UINT64(*value),
 540                                           obj_desc->common_field.
 541                                           access_byte_width));
 542                 }
 543         }
 544
 545         return_ACPI_STATUS(status);
 546 }
 547
 548 /*******************************************************************************
 549  *
 550  * FUNCTION:    acpi_ex_write_with_update_rule
 551  *
 552  * PARAMETERS:  obj_desc                - Field to be written
 553  *              Mask                    - bitmask within field datum
 554  *              field_value             - Value to write
 555  *              field_datum_byte_offset - Offset of datum within field
 556  *
 557  * RETURN:      Status
 558  *
 559  * DESCRIPTION: Apply the field update rule to a field write
 560  *
 561  ******************************************************************************/
 562
 563 acpi_status
 564 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc,
 565                                acpi_integer mask,
 566                                acpi_integer field_value,
 567                                u32 field_datum_byte_offset)
 568 {
 569         acpi_status status = AE_OK;
 570         acpi_integer merged_value;
 571         acpi_integer current_value;
 572
 573         ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask);
 574
 575         /* Start with the new bits  */
 576
 577         merged_value = field_value;
 578
 579         /* If the mask is all ones, we don't need to worry about the update rule */
 580
 581         if (mask != ACPI_INTEGER_MAX) {
 582
 583                 /* Decode the update rule */
 584
 585                 switch (obj_desc->common_field.
 586                         field_flags & AML_FIELD_UPDATE_RULE_MASK) {
 587                 case AML_FIELD_UPDATE_PRESERVE:
 588                         /*
 589                          * Check if update rule needs to be applied (not if mask is all
 590                          * ones)  The left shift drops the bits we want to ignore.
 591                          */
 592                         if ((~mask << (ACPI_MUL_8(sizeof(mask)) -
 593                                        ACPI_MUL_8(obj_desc->common_field.
 594                                                   access_byte_width))) != 0) {
 595                                 /*
 596                                  * Read the current contents of the byte/word/dword containing
 597                                  * the field, and merge with the new field value.
 598                                  */
 599                                 status =
 600                                     acpi_ex_field_datum_io(obj_desc,
 601                                                            field_datum_byte_offset,
 602                                                            &current_value,
 603                                                            ACPI_READ);
 604                                 if (ACPI_FAILURE(status)) {
 605                                         return_ACPI_STATUS(status);
 606                                 }
 607
 608                                 merged_value |= (current_value & ~mask);
 609                         }
 610                         break;
 611
 612                 case AML_FIELD_UPDATE_WRITE_AS_ONES:
 613
 614                         /* Set positions outside the field to all ones */
 615
 616                         merged_value |= ~mask;
 617                         break;
 618
 619                 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
 620
 621                         /* Set positions outside the field to all zeros */
 622
 623                         merged_value &= mask;
 624                         break;
 625
 626                 default:
 627
 628                         ACPI_ERROR((AE_INFO,
 629                                     "Unknown UpdateRule value: %X",
 630                                     (obj_desc->common_field.
 631                                      field_flags &
 632                                      AML_FIELD_UPDATE_RULE_MASK)));
 633                         return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
 634                 }
 635         }
 636
 637         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 638                           "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
 639                           ACPI_FORMAT_UINT64(mask),
 640                           field_datum_byte_offset,
 641                           obj_desc->common_field.access_byte_width,
 642                           ACPI_FORMAT_UINT64(field_value),
 643                           ACPI_FORMAT_UINT64(merged_value)));
 644
 645         /* Write the merged value */
 646
 647         status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset,
 648                                         &merged_value, ACPI_WRITE);
 649
 650         return_ACPI_STATUS(status);
 651 }
 652
 653 /*******************************************************************************
 654  *
 655  * FUNCTION:    acpi_ex_extract_from_field
 656  *
 657  * PARAMETERS:  obj_desc            - Field to be read
 658  *              Buffer              - Where to store the field data
 659  *              buffer_length       - Length of Buffer
 660  *
 661  * RETURN:      Status
 662  *
 663  * DESCRIPTION: Retrieve the current value of the given field
 664  *
 665  ******************************************************************************/
 666
 667 acpi_status
 668 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
 669                            void *buffer, u32 buffer_length)
 670 {
 671         acpi_status status;
 672         acpi_integer raw_datum;
 673         acpi_integer merged_datum;
 674         u32 field_offset = 0;
 675         u32 buffer_offset = 0;
 676         u32 buffer_tail_bits;
 677         u32 datum_count;
 678         u32 field_datum_count;
 679         u32 i;
 680
 681         ACPI_FUNCTION_TRACE(ex_extract_from_field);
 682
 683         /* Validate target buffer and clear it */
 684
 685         if (buffer_length <
 686             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
 687                 ACPI_ERROR((AE_INFO,
 688                             "Field size %X (bits) is too large for buffer (%X)",
 689                             obj_desc->common_field.bit_length, buffer_length));
 690
 691                 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
 692         }
 693         ACPI_MEMSET(buffer, 0, buffer_length);
 694
 695         /* Compute the number of datums (access width data items) */
 696
 697         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
 698                                        obj_desc->common_field.access_bit_width);
 699         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
 700                                              obj_desc->common_field.
 701                                              start_field_bit_offset,
 702                                              obj_desc->common_field.
 703                                              access_bit_width);
 704
 705         /* Priming read from the field */
 706
 707         status =
 708             acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
 709                                    ACPI_READ);
 710         if (ACPI_FAILURE(status)) {
 711                 return_ACPI_STATUS(status);
 712         }
 713         merged_datum =
 714             raw_datum >> obj_desc->common_field.start_field_bit_offset;
 715
 716         /* Read the rest of the field */
 717
 718         for (i = 1; i < field_datum_count; i++) {
 719
 720                 /* Get next input datum from the field */
 721
 722                 field_offset += obj_desc->common_field.access_byte_width;
 723                 status = acpi_ex_field_datum_io(obj_desc, field_offset,
 724                                                 &raw_datum, ACPI_READ);
 725                 if (ACPI_FAILURE(status)) {
 726                         return_ACPI_STATUS(status);
 727                 }
 728
 729                 /*
 730                  * Merge with previous datum if necessary.
 731                  *
 732                  * Note: Before the shift, check if the shift value will be larger than
 733                  * the integer size. If so, there is no need to perform the operation.
 734                  * This avoids the differences in behavior between different compilers
 735                  * concerning shift values larger than the target data width.
 736                  */
 737                 if ((obj_desc->common_field.access_bit_width -
 738                      obj_desc->common_field.start_field_bit_offset) <
 739                     ACPI_INTEGER_BIT_SIZE) {
 740                         merged_datum |=
 741                             raw_datum << (obj_desc->common_field.
 742                                           access_bit_width -
 743                                           obj_desc->common_field.
 744                                           start_field_bit_offset);
 745                 }
 746
 747                 if (i == datum_count) {
 748                         break;
 749                 }
 750
 751                 /* Write merged datum to target buffer */
 752
 753                 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
 754                             ACPI_MIN(obj_desc->common_field.access_byte_width,
 755                                      buffer_length - buffer_offset));
 756
 757                 buffer_offset += obj_desc->common_field.access_byte_width;
 758                 merged_datum =
 759                     raw_datum >> obj_desc->common_field.start_field_bit_offset;
 760         }
 761
 762         /* Mask off any extra bits in the last datum */
 763
 764         buffer_tail_bits = obj_desc->common_field.bit_length %
 765             obj_desc->common_field.access_bit_width;
 766         if (buffer_tail_bits) {
 767                 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
 768         }
 769
 770         /* Write the last datum to the buffer */
 771
 772         ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
 773                     ACPI_MIN(obj_desc->common_field.access_byte_width,
 774                              buffer_length - buffer_offset));
 775
 776         return_ACPI_STATUS(AE_OK);
 777 }
 778
 779 /*******************************************************************************
 780  *
 781  * FUNCTION:    acpi_ex_insert_into_field
 782  *
 783  * PARAMETERS:  obj_desc            - Field to be written
 784  *              Buffer              - Data to be written
 785  *              buffer_length       - Length of Buffer
 786  *
 787  * RETURN:      Status
 788  *
 789  * DESCRIPTION: Store the Buffer contents into the given field
 790  *
 791  ******************************************************************************/
 792
 793 acpi_status
 794 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
 795                           void *buffer, u32 buffer_length)
 796 {
 797         acpi_status status;
 798         acpi_integer mask;
 799         acpi_integer width_mask;
 800         acpi_integer merged_datum;
 801         acpi_integer raw_datum = 0;
 802         u32 field_offset = 0;
 803         u32 buffer_offset = 0;
 804         u32 buffer_tail_bits;
 805         u32 datum_count;
 806         u32 field_datum_count;
 807         u32 i;
 808
 809         ACPI_FUNCTION_TRACE(ex_insert_into_field);
 810
 811         /* Validate input buffer */
 812
 813         if (buffer_length <
 814             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
 815                 ACPI_ERROR((AE_INFO,
 816                             "Field size %X (bits) is too large for buffer (%X)",
 817                             obj_desc->common_field.bit_length, buffer_length));
 818
 819                 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
 820         }
 821
 822         /*
 823          * Create the bitmasks used for bit insertion.
 824          * Note: This if/else is used to bypass compiler differences with the
 825          * shift operator
 826          */
 827         if (obj_desc->common_field.access_bit_width == ACPI_INTEGER_BIT_SIZE) {
 828                 width_mask = ACPI_INTEGER_MAX;
 829         } else {
 830                 width_mask =
 831                     ACPI_MASK_BITS_ABOVE(obj_desc->common_field.
 832                                          access_bit_width);
 833         }
 834
 835         mask = width_mask &
 836             ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
 837
 838         /* Compute the number of datums (access width data items) */
 839
 840         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
 841                                        obj_desc->common_field.access_bit_width);
 842
 843         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
 844                                              obj_desc->common_field.
 845                                              start_field_bit_offset,
 846                                              obj_desc->common_field.
 847                                              access_bit_width);
 848
 849         /* Get initial Datum from the input buffer */
 850
 851         ACPI_MEMCPY(&raw_datum, buffer,
 852                     ACPI_MIN(obj_desc->common_field.access_byte_width,
 853                              buffer_length - buffer_offset));
 854
 855         merged_datum =
 856             raw_datum << obj_desc->common_field.start_field_bit_offset;
 857
 858         /* Write the entire field */
 859
 860         for (i = 1; i < field_datum_count; i++) {
 861
 862                 /* Write merged datum to the target field */
 863
 864                 merged_datum &= mask;
 865                 status = acpi_ex_write_with_update_rule(obj_desc, mask,
 866                                                         merged_datum,
 867                                                         field_offset);
 868                 if (ACPI_FAILURE(status)) {
 869                         return_ACPI_STATUS(status);
 870                 }
 871
 872                 field_offset += obj_desc->common_field.access_byte_width;
 873
 874                 /*
 875                  * Start new output datum by merging with previous input datum
 876                  * if necessary.
 877                  *
 878                  * Note: Before the shift, check if the shift value will be larger than
 879                  * the integer size. If so, there is no need to perform the operation.
 880                  * This avoids the differences in behavior between different compilers
 881                  * concerning shift values larger than the target data width.
 882                  */
 883                 if ((obj_desc->common_field.access_bit_width -
 884                      obj_desc->common_field.start_field_bit_offset) <
 885                     ACPI_INTEGER_BIT_SIZE) {
 886                         merged_datum =
 887                             raw_datum >> (obj_desc->common_field.
 888                                           access_bit_width -
 889                                           obj_desc->common_field.
 890                                           start_field_bit_offset);
 891                 } else {
 892                         merged_datum = 0;
 893                 }
 894
 895                 mask = width_mask;
 896
 897                 if (i == datum_count) {
 898                         break;
 899                 }
 900
 901                 /* Get the next input datum from the buffer */
 902
 903                 buffer_offset += obj_desc->common_field.access_byte_width;
 904                 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset,
 905                             ACPI_MIN(obj_desc->common_field.access_byte_width,
 906                                      buffer_length - buffer_offset));
 907                 merged_datum |=
 908                     raw_datum << obj_desc->common_field.start_field_bit_offset;
 909         }
 910
 911         /* Mask off any extra bits in the last datum */
 912
 913         buffer_tail_bits = (obj_desc->common_field.bit_length +
 914                             obj_desc->common_field.start_field_bit_offset) %
 915             obj_desc->common_field.access_bit_width;
 916         if (buffer_tail_bits) {
 917                 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
 918         }
 919
 920         /* Write the last datum to the field */
 921
 922         merged_datum &= mask;
 923         status = acpi_ex_write_with_update_rule(obj_desc,
 924                                                 mask, merged_datum,
 925                                                 field_offset);
 926
 927         return_ACPI_STATUS(status);
 928 }