drivers/acpi/executer/exfldio.c

   1 /******************************************************************************
   2  *
   3  * Module Name: exfldio - Aml Field I/O
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2006, 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         if (rgn_desc->region.space_id == ACPI_ADR_SPACE_SMBUS) {
 116                 /* SMBus has a non-linear address space */
 117
 118                 return_ACPI_STATUS(AE_OK);
 119         }
 120 #ifdef ACPI_UNDER_DEVELOPMENT
 121         /*
 122          * If the Field access is any_acc, we can now compute the optimal
 123          * access (because we know know the length of the parent region)
 124          */
 125         if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 126                 if (ACPI_FAILURE(status)) {
 127                         return_ACPI_STATUS(status);
 128                 }
 129         }
 130 #endif
 131
 132         /*
 133          * Validate the request.  The entire request from the byte offset for a
 134          * length of one field datum (access width) must fit within the region.
 135          * (Region length is specified in bytes)
 136          */
 137         if (rgn_desc->region.length < (obj_desc->common_field.base_byte_offset +
 138                                        field_datum_byte_offset +
 139                                        obj_desc->common_field.
 140                                        access_byte_width)) {
 141                 if (acpi_gbl_enable_interpreter_slack) {
 142                         /*
 143                          * Slack mode only:  We will go ahead and allow access to this
 144                          * field if it is within the region length rounded up to the next
 145                          * access width boundary.
 146                          */
 147                         if (ACPI_ROUND_UP(rgn_desc->region.length,
 148                                           obj_desc->common_field.
 149                                           access_byte_width) >=
 150                             (obj_desc->common_field.base_byte_offset +
 151                              (acpi_native_uint) obj_desc->common_field.
 152                              access_byte_width + field_datum_byte_offset)) {
 153                                 return_ACPI_STATUS(AE_OK);
 154                         }
 155                 }
 156
 157                 if (rgn_desc->region.length <
 158                     obj_desc->common_field.access_byte_width) {
 159                         /*
 160                          * This is the case where the access_type (acc_word, etc.) is wider
 161                          * than the region itself.  For example, a region of length one
 162                          * byte, and a field with Dword access specified.
 163                          */
 164                         ACPI_ERROR((AE_INFO,
 165                                     "Field [%4.4s] access width (%d bytes) too large for region [%4.4s] (length %X)",
 166                                     acpi_ut_get_node_name(obj_desc->
 167                                                           common_field.node),
 168                                     obj_desc->common_field.access_byte_width,
 169                                     acpi_ut_get_node_name(rgn_desc->region.
 170                                                           node),
 171                                     rgn_desc->region.length));
 172                 }
 173
 174                 /*
 175                  * Offset rounded up to next multiple of field width
 176                  * exceeds region length, indicate an error
 177                  */
 178                 ACPI_ERROR((AE_INFO,
 179                             "Field [%4.4s] Base+Offset+Width %X+%X+%X is beyond end of region [%4.4s] (length %X)",
 180                             acpi_ut_get_node_name(obj_desc->common_field.node),
 181                             obj_desc->common_field.base_byte_offset,
 182                             field_datum_byte_offset,
 183                             obj_desc->common_field.access_byte_width,
 184                             acpi_ut_get_node_name(rgn_desc->region.node),
 185                             rgn_desc->region.length));
 186
 187                 return_ACPI_STATUS(AE_AML_REGION_LIMIT);
 188         }
 189
 190         return_ACPI_STATUS(AE_OK);
 191 }
 192
 193 /*******************************************************************************
 194  *
 195  * FUNCTION:    acpi_ex_access_region
 196  *
 197  * PARAMETERS:  obj_desc                - Field to be read
 198  *              field_datum_byte_offset - Byte offset of this datum within the
 199  *                                        parent field
 200  *              Value                   - Where to store value (must at least
 201  *                                        the size of acpi_integer)
 202  *              Function                - Read or Write flag plus other region-
 203  *                                        dependent flags
 204  *
 205  * RETURN:      Status
 206  *
 207  * DESCRIPTION: Read or Write a single field datum to an Operation Region.
 208  *
 209  ******************************************************************************/
 210
 211 acpi_status
 212 acpi_ex_access_region(union acpi_operand_object *obj_desc,
 213                       u32 field_datum_byte_offset,
 214                       acpi_integer * value, u32 function)
 215 {
 216         acpi_status status;
 217         union acpi_operand_object *rgn_desc;
 218         acpi_physical_address address;
 219
 220         ACPI_FUNCTION_TRACE("ex_access_region");
 221
 222         /*
 223          * Ensure that the region operands are fully evaluated and verify
 224          * the validity of the request
 225          */
 226         status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset);
 227         if (ACPI_FAILURE(status)) {
 228                 return_ACPI_STATUS(status);
 229         }
 230
 231         /*
 232          * The physical address of this field datum is:
 233          *
 234          * 1) The base of the region, plus
 235          * 2) The base offset of the field, plus
 236          * 3) The current offset into the field
 237          */
 238         rgn_desc = obj_desc->common_field.region_obj;
 239         address = rgn_desc->region.address +
 240             obj_desc->common_field.base_byte_offset + field_datum_byte_offset;
 241
 242         if ((function & ACPI_IO_MASK) == ACPI_READ) {
 243                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
 244         } else {
 245                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
 246         }
 247
 248         ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
 249                               " Region [%s:%X], Width %X, byte_base %X, Offset %X at %8.8X%8.8X\n",
 250                               acpi_ut_get_region_name(rgn_desc->region.
 251                                                       space_id),
 252                               rgn_desc->region.space_id,
 253                               obj_desc->common_field.access_byte_width,
 254                               obj_desc->common_field.base_byte_offset,
 255                               field_datum_byte_offset,
 256                               ACPI_FORMAT_UINT64(address)));
 257
 258         /* Invoke the appropriate address_space/op_region handler */
 259
 260         status = acpi_ev_address_space_dispatch(rgn_desc, function,
 261                                                 address,
 262                                                 ACPI_MUL_8(obj_desc->
 263                                                            common_field.
 264                                                            access_byte_width),
 265                                                 value);
 266
 267         if (ACPI_FAILURE(status)) {
 268                 if (status == AE_NOT_IMPLEMENTED) {
 269                         ACPI_ERROR((AE_INFO,
 270                                     "Region %s(%X) not implemented",
 271                                     acpi_ut_get_region_name(rgn_desc->region.
 272                                                             space_id),
 273                                     rgn_desc->region.space_id));
 274                 } else if (status == AE_NOT_EXIST) {
 275                         ACPI_ERROR((AE_INFO,
 276                                     "Region %s(%X) has no handler",
 277                                     acpi_ut_get_region_name(rgn_desc->region.
 278                                                             space_id),
 279                                     rgn_desc->region.space_id));
 280                 }
 281         }
 282
 283         return_ACPI_STATUS(status);
 284 }
 285
 286 /*******************************************************************************
 287  *
 288  * FUNCTION:    acpi_ex_register_overflow
 289  *
 290  * PARAMETERS:  obj_desc                - Register(Field) to be written
 291  *              Value                   - Value to be stored
 292  *
 293  * RETURN:      TRUE if value overflows the field, FALSE otherwise
 294  *
 295  * DESCRIPTION: Check if a value is out of range of the field being written.
 296  *              Used to check if the values written to Index and Bank registers
 297  *              are out of range.  Normally, the value is simply truncated
 298  *              to fit the field, but this case is most likely a serious
 299  *              coding error in the ASL.
 300  *
 301  ******************************************************************************/
 302
 303 static u8
 304 acpi_ex_register_overflow(union acpi_operand_object *obj_desc,
 305                           acpi_integer value)
 306 {
 307
 308         if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
 309                 /*
 310                  * The field is large enough to hold the maximum integer, so we can
 311                  * never overflow it.
 312                  */
 313                 return (FALSE);
 314         }
 315
 316         if (value >= ((acpi_integer) 1 << obj_desc->common_field.bit_length)) {
 317                 /*
 318                  * The Value is larger than the maximum value that can fit into
 319                  * the register.
 320                  */
 321                 return (TRUE);
 322         }
 323
 324         /* The Value will fit into the field with no truncation */
 325
 326         return (FALSE);
 327 }
 328
 329 /*******************************************************************************
 330  *
 331  * FUNCTION:    acpi_ex_field_datum_io
 332  *
 333  * PARAMETERS:  obj_desc                - Field to be read
 334  *              field_datum_byte_offset - Byte offset of this datum within the
 335  *                                        parent field
 336  *              Value                   - Where to store value (must be 64 bits)
 337  *              read_write              - Read or Write flag
 338  *
 339  * RETURN:      Status
 340  *
 341  * DESCRIPTION: Read or Write a single datum of a field.  The field_type is
 342  *              demultiplexed here to handle the different types of fields
 343  *              (buffer_field, region_field, index_field, bank_field)
 344  *
 345  ******************************************************************************/
 346
 347 static acpi_status
 348 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
 349                        u32 field_datum_byte_offset,
 350                        acpi_integer * value, u32 read_write)
 351 {
 352         acpi_status status;
 353         acpi_integer local_value;
 354
 355         ACPI_FUNCTION_TRACE_U32("ex_field_datum_io", field_datum_byte_offset);
 356
 357         if (read_write == ACPI_READ) {
 358                 if (!value) {
 359                         local_value = 0;
 360
 361                         /* To support reads without saving return value */
 362                         value = &local_value;
 363                 }
 364
 365                 /* Clear the entire return buffer first, [Very Important!] */
 366
 367                 *value = 0;
 368         }
 369
 370         /*
 371          * The four types of fields are:
 372          *
 373          * buffer_field - Read/write from/to a Buffer
 374          * region_field - Read/write from/to a Operation Region.
 375          * bank_field  - Write to a Bank Register, then read/write from/to an
 376          *               operation_region
 377          * index_field - Write to an Index Register, then read/write from/to a
 378          *               Data Register
 379          */
 380         switch (ACPI_GET_OBJECT_TYPE(obj_desc)) {
 381         case ACPI_TYPE_BUFFER_FIELD:
 382                 /*
 383                  * If the buffer_field arguments have not been previously evaluated,
 384                  * evaluate them now and save the results.
 385                  */
 386                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 387                         status = acpi_ds_get_buffer_field_arguments(obj_desc);
 388                         if (ACPI_FAILURE(status)) {
 389                                 return_ACPI_STATUS(status);
 390                         }
 391                 }
 392
 393                 if (read_write == ACPI_READ) {
 394                         /*
 395                          * Copy the data from the source buffer.
 396                          * Length is the field width in bytes.
 397                          */
 398                         ACPI_MEMCPY(value,
 399                                     (obj_desc->buffer_field.buffer_obj)->buffer.
 400                                     pointer +
 401                                     obj_desc->buffer_field.base_byte_offset +
 402                                     field_datum_byte_offset,
 403                                     obj_desc->common_field.access_byte_width);
 404                 } else {
 405                         /*
 406                          * Copy the data to the target buffer.
 407                          * Length is the field width in bytes.
 408                          */
 409                         ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer.
 410                                     pointer +
 411                                     obj_desc->buffer_field.base_byte_offset +
 412                                     field_datum_byte_offset, value,
 413                                     obj_desc->common_field.access_byte_width);
 414                 }
 415
 416                 status = AE_OK;
 417                 break;
 418
 419         case ACPI_TYPE_LOCAL_BANK_FIELD:
 420
 421                 /*
 422                  * Ensure that the bank_value is not beyond the capacity of
 423                  * the register
 424                  */
 425                 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
 426                                               (acpi_integer) obj_desc->
 427                                               bank_field.value)) {
 428                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
 429                 }
 430
 431                 /*
 432                  * For bank_fields, we must write the bank_value to the bank_register
 433                  * (itself a region_field) before we can access the data.
 434                  */
 435                 status =
 436                     acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
 437                                               &obj_desc->bank_field.value,
 438                                               sizeof(obj_desc->bank_field.
 439                                                      value));
 440                 if (ACPI_FAILURE(status)) {
 441                         return_ACPI_STATUS(status);
 442                 }
 443
 444                 /*
 445                  * Now that the Bank has been selected, fall through to the
 446                  * region_field case and write the datum to the Operation Region
 447                  */
 448
 449                 /*lint -fallthrough */
 450
 451         case ACPI_TYPE_LOCAL_REGION_FIELD:
 452                 /*
 453                  * For simple region_fields, we just directly access the owning
 454                  * Operation Region.
 455                  */
 456                 status =
 457                     acpi_ex_access_region(obj_desc, field_datum_byte_offset,
 458                                           value, read_write);
 459                 break;
 460
 461         case ACPI_TYPE_LOCAL_INDEX_FIELD:
 462
 463                 /*
 464                  * Ensure that the index_value is not beyond the capacity of
 465                  * the register
 466                  */
 467                 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
 468                                               (acpi_integer) obj_desc->
 469                                               index_field.value)) {
 470                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
 471                 }
 472
 473                 /* Write the index value to the index_register (itself a region_field) */
 474
 475                 field_datum_byte_offset += obj_desc->index_field.value;
 476
 477                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 478                                   "Write to Index Register: Value %8.8X\n",
 479                                   field_datum_byte_offset));
 480
 481                 status =
 482                     acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
 483                                               &field_datum_byte_offset,
 484                                               sizeof(field_datum_byte_offset));
 485                 if (ACPI_FAILURE(status)) {
 486                         return_ACPI_STATUS(status);
 487                 }
 488
 489                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 490                                   "I/O to Data Register: value_ptr %p\n",
 491                                   value));
 492
 493                 if (read_write == ACPI_READ) {
 494                         /* Read the datum from the data_register */
 495
 496                         status =
 497                             acpi_ex_extract_from_field(obj_desc->index_field.
 498                                                        data_obj, value,
 499                                                        sizeof(acpi_integer));
 500                 } else {
 501                         /* Write the datum to the data_register */
 502
 503                         status =
 504                             acpi_ex_insert_into_field(obj_desc->index_field.
 505                                                       data_obj, value,
 506                                                       sizeof(acpi_integer));
 507                 }
 508                 break;
 509
 510         default:
 511
 512                 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %X",
 513                             ACPI_GET_OBJECT_TYPE(obj_desc)));
 514                 status = AE_AML_INTERNAL;
 515                 break;
 516         }
 517
 518         if (ACPI_SUCCESS(status)) {
 519                 if (read_write == ACPI_READ) {
 520                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 521                                           "Value Read %8.8X%8.8X, Width %d\n",
 522                                           ACPI_FORMAT_UINT64(*value),
 523                                           obj_desc->common_field.
 524                                           access_byte_width));
 525                 } else {
 526                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 527                                           "Value Written %8.8X%8.8X, Width %d\n",
 528                                           ACPI_FORMAT_UINT64(*value),
 529                                           obj_desc->common_field.
 530                                           access_byte_width));
 531                 }
 532         }
 533
 534         return_ACPI_STATUS(status);
 535 }
 536
 537 /*******************************************************************************
 538  *
 539  * FUNCTION:    acpi_ex_write_with_update_rule
 540  *
 541  * PARAMETERS:  obj_desc                - Field to be written
 542  *              Mask                    - bitmask within field datum
 543  *              field_value             - Value to write
 544  *              field_datum_byte_offset - Offset of datum within field
 545  *
 546  * RETURN:      Status
 547  *
 548  * DESCRIPTION: Apply the field update rule to a field write
 549  *
 550  ******************************************************************************/
 551
 552 acpi_status
 553 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc,
 554                                acpi_integer mask,
 555                                acpi_integer field_value,
 556                                u32 field_datum_byte_offset)
 557 {
 558         acpi_status status = AE_OK;
 559         acpi_integer merged_value;
 560         acpi_integer current_value;
 561
 562         ACPI_FUNCTION_TRACE_U32("ex_write_with_update_rule", mask);
 563
 564         /* Start with the new bits  */
 565
 566         merged_value = field_value;
 567
 568         /* If the mask is all ones, we don't need to worry about the update rule */
 569
 570         if (mask != ACPI_INTEGER_MAX) {
 571                 /* Decode the update rule */
 572
 573                 switch (obj_desc->common_field.
 574                         field_flags & AML_FIELD_UPDATE_RULE_MASK) {
 575                 case AML_FIELD_UPDATE_PRESERVE:
 576                         /*
 577                          * Check if update rule needs to be applied (not if mask is all
 578                          * ones)  The left shift drops the bits we want to ignore.
 579                          */
 580                         if ((~mask << (ACPI_MUL_8(sizeof(mask)) -
 581                                        ACPI_MUL_8(obj_desc->common_field.
 582                                                   access_byte_width))) != 0) {
 583                                 /*
 584                                  * Read the current contents of the byte/word/dword containing
 585                                  * the field, and merge with the new field value.
 586                                  */
 587                                 status =
 588                                     acpi_ex_field_datum_io(obj_desc,
 589                                                            field_datum_byte_offset,
 590                                                            &current_value,
 591                                                            ACPI_READ);
 592                                 if (ACPI_FAILURE(status)) {
 593                                         return_ACPI_STATUS(status);
 594                                 }
 595
 596                                 merged_value |= (current_value & ~mask);
 597                         }
 598                         break;
 599
 600                 case AML_FIELD_UPDATE_WRITE_AS_ONES:
 601
 602                         /* Set positions outside the field to all ones */
 603
 604                         merged_value |= ~mask;
 605                         break;
 606
 607                 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
 608
 609                         /* Set positions outside the field to all zeros */
 610
 611                         merged_value &= mask;
 612                         break;
 613
 614                 default:
 615
 616                         ACPI_ERROR((AE_INFO,
 617                                     "Unknown update_rule value: %X",
 618                                     (obj_desc->common_field.
 619                                      field_flags &
 620                                      AML_FIELD_UPDATE_RULE_MASK)));
 621                         return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
 622                 }
 623         }
 624
 625         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 626                           "Mask %8.8X%8.8X, datum_offset %X, Width %X, Value %8.8X%8.8X, merged_value %8.8X%8.8X\n",
 627                           ACPI_FORMAT_UINT64(mask),
 628                           field_datum_byte_offset,
 629                           obj_desc->common_field.access_byte_width,
 630                           ACPI_FORMAT_UINT64(field_value),
 631                           ACPI_FORMAT_UINT64(merged_value)));
 632
 633         /* Write the merged value */
 634
 635         status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset,
 636                                         &merged_value, ACPI_WRITE);
 637
 638         return_ACPI_STATUS(status);
 639 }
 640
 641 /*******************************************************************************
 642  *
 643  * FUNCTION:    acpi_ex_extract_from_field
 644  *
 645  * PARAMETERS:  obj_desc            - Field to be read
 646  *              Buffer              - Where to store the field data
 647  *              buffer_length       - Length of Buffer
 648  *
 649  * RETURN:      Status
 650  *
 651  * DESCRIPTION: Retrieve the current value of the given field
 652  *
 653  ******************************************************************************/
 654
 655 acpi_status
 656 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
 657                            void *buffer, u32 buffer_length)
 658 {
 659         acpi_status status;
 660         acpi_integer raw_datum;
 661         acpi_integer merged_datum;
 662         u32 field_offset = 0;
 663         u32 buffer_offset = 0;
 664         u32 buffer_tail_bits;
 665         u32 datum_count;
 666         u32 field_datum_count;
 667         u32 i;
 668
 669         ACPI_FUNCTION_TRACE("ex_extract_from_field");
 670
 671         /* Validate target buffer and clear it */
 672
 673         if (buffer_length <
 674             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
 675                 ACPI_ERROR((AE_INFO,
 676                             "Field size %X (bits) is too large for buffer (%X)",
 677                             obj_desc->common_field.bit_length, buffer_length));
 678
 679                 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
 680         }
 681         ACPI_MEMSET(buffer, 0, buffer_length);
 682
 683         /* Compute the number of datums (access width data items) */
 684
 685         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
 686                                        obj_desc->common_field.access_bit_width);
 687         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
 688                                              obj_desc->common_field.
 689                                              start_field_bit_offset,
 690                                              obj_desc->common_field.
 691                                              access_bit_width);
 692
 693         /* Priming read from the field */
 694
 695         status =
 696             acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
 697                                    ACPI_READ);
 698         if (ACPI_FAILURE(status)) {
 699                 return_ACPI_STATUS(status);
 700         }
 701         merged_datum =
 702             raw_datum >> obj_desc->common_field.start_field_bit_offset;
 703
 704         /* Read the rest of the field */
 705
 706         for (i = 1; i < field_datum_count; i++) {
 707                 /* Get next input datum from the field */
 708
 709                 field_offset += obj_desc->common_field.access_byte_width;
 710                 status = acpi_ex_field_datum_io(obj_desc, field_offset,
 711                                                 &raw_datum, ACPI_READ);
 712                 if (ACPI_FAILURE(status)) {
 713                         return_ACPI_STATUS(status);
 714                 }
 715
 716                 /* Merge with previous datum if necessary */
 717
 718                 merged_datum |= raw_datum <<
 719                     (obj_desc->common_field.access_bit_width -
 720                      obj_desc->common_field.start_field_bit_offset);
 721
 722                 if (i == datum_count) {
 723                         break;
 724                 }
 725
 726                 /* Write merged datum to target buffer */
 727
 728                 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
 729                             ACPI_MIN(obj_desc->common_field.access_byte_width,
 730                                      buffer_length - buffer_offset));
 731
 732                 buffer_offset += obj_desc->common_field.access_byte_width;
 733                 merged_datum =
 734                     raw_datum >> obj_desc->common_field.start_field_bit_offset;
 735         }
 736
 737         /* Mask off any extra bits in the last datum */
 738
 739         buffer_tail_bits = obj_desc->common_field.bit_length %
 740             obj_desc->common_field.access_bit_width;
 741         if (buffer_tail_bits) {
 742                 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
 743         }
 744
 745         /* Write the last datum to the buffer */
 746
 747         ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
 748                     ACPI_MIN(obj_desc->common_field.access_byte_width,
 749                              buffer_length - buffer_offset));
 750
 751         return_ACPI_STATUS(AE_OK);
 752 }
 753
 754 /*******************************************************************************
 755  *
 756  * FUNCTION:    acpi_ex_insert_into_field
 757  *
 758  * PARAMETERS:  obj_desc            - Field to be written
 759  *              Buffer              - Data to be written
 760  *              buffer_length       - Length of Buffer
 761  *
 762  * RETURN:      Status
 763  *
 764  * DESCRIPTION: Store the Buffer contents into the given field
 765  *
 766  ******************************************************************************/
 767
 768 acpi_status
 769 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
 770                           void *buffer, u32 buffer_length)
 771 {
 772         acpi_status status;
 773         acpi_integer mask;
 774         acpi_integer merged_datum;
 775         acpi_integer raw_datum = 0;
 776         u32 field_offset = 0;
 777         u32 buffer_offset = 0;
 778         u32 buffer_tail_bits;
 779         u32 datum_count;
 780         u32 field_datum_count;
 781         u32 i;
 782
 783         ACPI_FUNCTION_TRACE("ex_insert_into_field");
 784
 785         /* Validate input buffer */
 786
 787         if (buffer_length <
 788             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
 789                 ACPI_ERROR((AE_INFO,
 790                             "Field size %X (bits) is too large for buffer (%X)",
 791                             obj_desc->common_field.bit_length, buffer_length));
 792
 793                 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
 794         }
 795
 796         /* Compute the number of datums (access width data items) */
 797
 798         mask =
 799             ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
 800         datum_count =
 801             ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
 802                              obj_desc->common_field.access_bit_width);
 803         field_datum_count =
 804             ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
 805                              obj_desc->common_field.start_field_bit_offset,
 806                              obj_desc->common_field.access_bit_width);
 807
 808         /* Get initial Datum from the input buffer */
 809
 810         ACPI_MEMCPY(&raw_datum, buffer,
 811                     ACPI_MIN(obj_desc->common_field.access_byte_width,
 812                              buffer_length - buffer_offset));
 813
 814         merged_datum =
 815             raw_datum << obj_desc->common_field.start_field_bit_offset;
 816
 817         /* Write the entire field */
 818
 819         for (i = 1; i < field_datum_count; i++) {
 820                 /* Write merged datum to the target field */
 821
 822                 merged_datum &= mask;
 823                 status = acpi_ex_write_with_update_rule(obj_desc, mask,
 824                                                         merged_datum,
 825                                                         field_offset);
 826                 if (ACPI_FAILURE(status)) {
 827                         return_ACPI_STATUS(status);
 828                 }
 829
 830                 /* Start new output datum by merging with previous input datum */
 831
 832                 field_offset += obj_desc->common_field.access_byte_width;
 833                 merged_datum = raw_datum >>
 834                     (obj_desc->common_field.access_bit_width -
 835                      obj_desc->common_field.start_field_bit_offset);
 836                 mask = ACPI_INTEGER_MAX;
 837
 838                 if (i == datum_count) {
 839                         break;
 840                 }
 841
 842                 /* Get the next input datum from the buffer */
 843
 844                 buffer_offset += obj_desc->common_field.access_byte_width;
 845                 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset,
 846                             ACPI_MIN(obj_desc->common_field.access_byte_width,
 847                                      buffer_length - buffer_offset));
 848                 merged_datum |=
 849                     raw_datum << obj_desc->common_field.start_field_bit_offset;
 850         }
 851
 852         /* Mask off any extra bits in the last datum */
 853
 854         buffer_tail_bits = (obj_desc->common_field.bit_length +
 855                             obj_desc->common_field.start_field_bit_offset) %
 856             obj_desc->common_field.access_bit_width;
 857         if (buffer_tail_bits) {
 858                 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
 859         }
 860
 861         /* Write the last datum to the field */
 862
 863         merged_datum &= mask;
 864         status = acpi_ex_write_with_update_rule(obj_desc,
 865                                                 mask, merged_datum,
 866                                                 field_offset);
 867
 868         return_ACPI_STATUS(status);
 869 }