git.oblomov.eu Git - linux-2.6/blob - drivers/acpi/acpica/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 "accommon.h"
  46 #include "acinterp.h"
  47 #include "amlcode.h"
  48 #include "acevents.h"
  49 #include "acdispat.h"
  50
  51 #define _COMPONENT          ACPI_EXECUTER
  52 ACPI_MODULE_NAME("exfldio")
  53
  54 /* Local prototypes */
  55 static acpi_status
  56 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
  57                        u32 field_datum_byte_offset,
  58                        acpi_integer * value, u32 read_write);
  59
  60 static u8
  61 acpi_ex_register_overflow(union acpi_operand_object *obj_desc,
  62                           acpi_integer value);
  63
  64 static acpi_status
  65 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
  66                      u32 field_datum_byte_offset);
  67
  68 /*******************************************************************************
  69  *
  70  * FUNCTION:    acpi_ex_setup_region
  71  *
  72  * PARAMETERS:  obj_desc                - Field to be read or written
  73  *              field_datum_byte_offset - Byte offset of this datum within the
  74  *                                        parent field
  75  *
  76  * RETURN:      Status
  77  *
  78  * DESCRIPTION: Common processing for acpi_ex_extract_from_field and
  79  *              acpi_ex_insert_into_field. Initialize the Region if necessary and
  80  *              validate the request.
  81  *
  82  ******************************************************************************/
  83
  84 static acpi_status
  85 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
  86                      u32 field_datum_byte_offset)
  87 {
  88         acpi_status status = AE_OK;
  89         union acpi_operand_object *rgn_desc;
  90
  91         ACPI_FUNCTION_TRACE_U32(ex_setup_region, field_datum_byte_offset);
  92
  93         rgn_desc = obj_desc->common_field.region_obj;
  94
  95         /* We must have a valid region */
  96
  97         if (rgn_desc->common.type != ACPI_TYPE_REGION) {
  98                 ACPI_ERROR((AE_INFO, "Needed Region, found type %X (%s)",
  99                             rgn_desc->common.type,
 100                             acpi_ut_get_object_type_name(rgn_desc)));
 101
 102                 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
 103         }
 104
 105         /*
 106          * If the Region Address and Length have not been previously evaluated,
 107          * evaluate them now and save the results.
 108          */
 109         if (!(rgn_desc->common.flags & AOPOBJ_DATA_VALID)) {
 110                 status = acpi_ds_get_region_arguments(rgn_desc);
 111                 if (ACPI_FAILURE(status)) {
 112                         return_ACPI_STATUS(status);
 113                 }
 114         }
 115
 116         /*
 117          * Exit now for SMBus address space, it has a non-linear address space
 118          * and the request cannot be directly validated
 119          */
 120         if (rgn_desc->region.space_id == ACPI_ADR_SPACE_SMBUS) {
 121
 122                 /* SMBus has a non-linear address space */
 123
 124                 return_ACPI_STATUS(AE_OK);
 125         }
 126 #ifdef ACPI_UNDER_DEVELOPMENT
 127         /*
 128          * If the Field access is any_acc, we can now compute the optimal
 129          * access (because we know know the length of the parent region)
 130          */
 131         if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 132                 if (ACPI_FAILURE(status)) {
 133                         return_ACPI_STATUS(status);
 134                 }
 135         }
 136 #endif
 137
 138         /*
 139          * Validate the request.  The entire request from the byte offset for a
 140          * length of one field datum (access width) must fit within the region.
 141          * (Region length is specified in bytes)
 142          */
 143         if (rgn_desc->region.length <
 144             (obj_desc->common_field.base_byte_offset +
 145              field_datum_byte_offset +
 146              obj_desc->common_field.access_byte_width)) {
 147                 if (acpi_gbl_enable_interpreter_slack) {
 148                         /*
 149                          * Slack mode only:  We will go ahead and allow access to this
 150                          * field if it is within the region length rounded up to the next
 151                          * access width boundary. acpi_size cast for 64-bit compile.
 152                          */
 153                         if (ACPI_ROUND_UP(rgn_desc->region.length,
 154                                           obj_desc->common_field.
 155                                           access_byte_width) >=
 156                             ((acpi_size) obj_desc->common_field.
 157                              base_byte_offset +
 158                              obj_desc->common_field.access_byte_width +
 159                              field_datum_byte_offset)) {
 160                                 return_ACPI_STATUS(AE_OK);
 161                         }
 162                 }
 163
 164                 if (rgn_desc->region.length <
 165                     obj_desc->common_field.access_byte_width) {
 166                         /*
 167                          * This is the case where the access_type (acc_word, etc.) is wider
 168                          * than the region itself.  For example, a region of length one
 169                          * byte, and a field with Dword access specified.
 170                          */
 171                         ACPI_ERROR((AE_INFO,
 172                                     "Field [%4.4s] access width (%d bytes) too large for region [%4.4s] (length %X)",
 173                                     acpi_ut_get_node_name(obj_desc->
 174                                                           common_field.node),
 175                                     obj_desc->common_field.access_byte_width,
 176                                     acpi_ut_get_node_name(rgn_desc->region.
 177                                                           node),
 178                                     rgn_desc->region.length));
 179                 }
 180
 181                 /*
 182                  * Offset rounded up to next multiple of field width
 183                  * exceeds region length, indicate an error
 184                  */
 185                 ACPI_ERROR((AE_INFO,
 186                             "Field [%4.4s] Base+Offset+Width %X+%X+%X is beyond end of region [%4.4s] (length %X)",
 187                             acpi_ut_get_node_name(obj_desc->common_field.node),
 188                             obj_desc->common_field.base_byte_offset,
 189                             field_datum_byte_offset,
 190                             obj_desc->common_field.access_byte_width,
 191                             acpi_ut_get_node_name(rgn_desc->region.node),
 192                             rgn_desc->region.length));
 193
 194                 return_ACPI_STATUS(AE_AML_REGION_LIMIT);
 195         }
 196
 197         return_ACPI_STATUS(AE_OK);
 198 }
 199
 200 /*******************************************************************************
 201  *
 202  * FUNCTION:    acpi_ex_access_region
 203  *
 204  * PARAMETERS:  obj_desc                - Field to be read
 205  *              field_datum_byte_offset - Byte offset of this datum within the
 206  *                                        parent field
 207  *              Value                   - Where to store value (must at least
 208  *                                        the size of acpi_integer)
 209  *              Function                - Read or Write flag plus other region-
 210  *                                        dependent flags
 211  *
 212  * RETURN:      Status
 213  *
 214  * DESCRIPTION: Read or Write a single field datum to an Operation Region.
 215  *
 216  ******************************************************************************/
 217
 218 acpi_status
 219 acpi_ex_access_region(union acpi_operand_object *obj_desc,
 220                       u32 field_datum_byte_offset,
 221                       acpi_integer * value, u32 function)
 222 {
 223         acpi_status status;
 224         union acpi_operand_object *rgn_desc;
 225         acpi_physical_address address;
 226
 227         ACPI_FUNCTION_TRACE(ex_access_region);
 228
 229         /*
 230          * Ensure that the region operands are fully evaluated and verify
 231          * the validity of the request
 232          */
 233         status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset);
 234         if (ACPI_FAILURE(status)) {
 235                 return_ACPI_STATUS(status);
 236         }
 237
 238         /*
 239          * The physical address of this field datum is:
 240          *
 241          * 1) The base of the region, plus
 242          * 2) The base offset of the field, plus
 243          * 3) The current offset into the field
 244          */
 245         rgn_desc = obj_desc->common_field.region_obj;
 246         address = rgn_desc->region.address +
 247             obj_desc->common_field.base_byte_offset + field_datum_byte_offset;
 248
 249         if ((function & ACPI_IO_MASK) == ACPI_READ) {
 250                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
 251         } else {
 252                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
 253         }
 254
 255         ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
 256                               " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n",
 257                               acpi_ut_get_region_name(rgn_desc->region.
 258                                                       space_id),
 259                               rgn_desc->region.space_id,
 260                               obj_desc->common_field.access_byte_width,
 261                               obj_desc->common_field.base_byte_offset,
 262                               field_datum_byte_offset, ACPI_CAST_PTR(void,
 263                                                                      address)));
 264
 265         /* Invoke the appropriate address_space/op_region handler */
 266
 267         status = acpi_ev_address_space_dispatch(rgn_desc, function,
 268                                                 address,
 269                                                 ACPI_MUL_8(obj_desc->
 270                                                            common_field.
 271                                                            access_byte_width),
 272                                                 value);
 273
 274         if (ACPI_FAILURE(status)) {
 275                 if (status == AE_NOT_IMPLEMENTED) {
 276                         ACPI_ERROR((AE_INFO,
 277                                     "Region %s(%X) not implemented",
 278                                     acpi_ut_get_region_name(rgn_desc->region.
 279                                                             space_id),
 280                                     rgn_desc->region.space_id));
 281                 } else if (status == AE_NOT_EXIST) {
 282                         ACPI_ERROR((AE_INFO,
 283                                     "Region %s(%X) has no handler",
 284                                     acpi_ut_get_region_name(rgn_desc->region.
 285                                                             space_id),
 286                                     rgn_desc->region.space_id));
 287                 }
 288         }
 289
 290         return_ACPI_STATUS(status);
 291 }
 292
 293 /*******************************************************************************
 294  *
 295  * FUNCTION:    acpi_ex_register_overflow
 296  *
 297  * PARAMETERS:  obj_desc                - Register(Field) to be written
 298  *              Value                   - Value to be stored
 299  *
 300  * RETURN:      TRUE if value overflows the field, FALSE otherwise
 301  *
 302  * DESCRIPTION: Check if a value is out of range of the field being written.
 303  *              Used to check if the values written to Index and Bank registers
 304  *              are out of range.  Normally, the value is simply truncated
 305  *              to fit the field, but this case is most likely a serious
 306  *              coding error in the ASL.
 307  *
 308  ******************************************************************************/
 309
 310 static u8
 311 acpi_ex_register_overflow(union acpi_operand_object *obj_desc,
 312                           acpi_integer value)
 313 {
 314
 315         if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
 316                 /*
 317                  * The field is large enough to hold the maximum integer, so we can
 318                  * never overflow it.
 319                  */
 320                 return (FALSE);
 321         }
 322
 323         if (value >= ((acpi_integer) 1 << obj_desc->common_field.bit_length)) {
 324                 /*
 325                  * The Value is larger than the maximum value that can fit into
 326                  * the register.
 327                  */
 328                 return (TRUE);
 329         }
 330
 331         /* The Value will fit into the field with no truncation */
 332
 333         return (FALSE);
 334 }
 335
 336 /*******************************************************************************
 337  *
 338  * FUNCTION:    acpi_ex_field_datum_io
 339  *
 340  * PARAMETERS:  obj_desc                - Field to be read
 341  *              field_datum_byte_offset - Byte offset of this datum within the
 342  *                                        parent field
 343  *              Value                   - Where to store value (must be 64 bits)
 344  *              read_write              - Read or Write flag
 345  *
 346  * RETURN:      Status
 347  *
 348  * DESCRIPTION: Read or Write a single datum of a field.  The field_type is
 349  *              demultiplexed here to handle the different types of fields
 350  *              (buffer_field, region_field, index_field, bank_field)
 351  *
 352  ******************************************************************************/
 353
 354 static acpi_status
 355 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
 356                        u32 field_datum_byte_offset,
 357                        acpi_integer * value, u32 read_write)
 358 {
 359         acpi_status status;
 360         acpi_integer local_value;
 361
 362         ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
 363
 364         if (read_write == ACPI_READ) {
 365                 if (!value) {
 366                         local_value = 0;
 367
 368                         /* To support reads without saving return value */
 369                         value = &local_value;
 370                 }
 371
 372                 /* Clear the entire return buffer first, [Very Important!] */
 373
 374                 *value = 0;
 375         }
 376
 377         /*
 378          * The four types of fields are:
 379          *
 380          * buffer_field - Read/write from/to a Buffer
 381          * region_field - Read/write from/to a Operation Region.
 382          * bank_field  - Write to a Bank Register, then read/write from/to an
 383          *               operation_region
 384          * index_field - Write to an Index Register, then read/write from/to a
 385          *               Data Register
 386          */
 387         switch (obj_desc->common.type) {
 388         case ACPI_TYPE_BUFFER_FIELD:
 389                 /*
 390                  * If the buffer_field arguments have not been previously evaluated,
 391                  * evaluate them now and save the results.
 392                  */
 393                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 394                         status = acpi_ds_get_buffer_field_arguments(obj_desc);
 395                         if (ACPI_FAILURE(status)) {
 396                                 return_ACPI_STATUS(status);
 397                         }
 398                 }
 399
 400                 if (read_write == ACPI_READ) {
 401                         /*
 402                          * Copy the data from the source buffer.
 403                          * Length is the field width in bytes.
 404                          */
 405                         ACPI_MEMCPY(value,
 406                                     (obj_desc->buffer_field.buffer_obj)->buffer.
 407                                     pointer +
 408                                     obj_desc->buffer_field.base_byte_offset +
 409                                     field_datum_byte_offset,
 410                                     obj_desc->common_field.access_byte_width);
 411                 } else {
 412                         /*
 413                          * Copy the data to the target buffer.
 414                          * Length is the field width in bytes.
 415                          */
 416                         ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer.
 417                                     pointer +
 418                                     obj_desc->buffer_field.base_byte_offset +
 419                                     field_datum_byte_offset, value,
 420                                     obj_desc->common_field.access_byte_width);
 421                 }
 422
 423                 status = AE_OK;
 424                 break;
 425
 426         case ACPI_TYPE_LOCAL_BANK_FIELD:
 427
 428                 /*
 429                  * Ensure that the bank_value is not beyond the capacity of
 430                  * the register
 431                  */
 432                 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
 433                                               (acpi_integer) obj_desc->
 434                                               bank_field.value)) {
 435                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
 436                 }
 437
 438                 /*
 439                  * For bank_fields, we must write the bank_value to the bank_register
 440                  * (itself a region_field) before we can access the data.
 441                  */
 442                 status =
 443                     acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
 444                                               &obj_desc->bank_field.value,
 445                                               sizeof(obj_desc->bank_field.
 446                                                      value));
 447                 if (ACPI_FAILURE(status)) {
 448                         return_ACPI_STATUS(status);
 449                 }
 450
 451                 /*
 452                  * Now that the Bank has been selected, fall through to the
 453                  * region_field case and write the datum to the Operation Region
 454                  */
 455
 456                 /*lint -fallthrough */
 457
 458         case ACPI_TYPE_LOCAL_REGION_FIELD:
 459                 /*
 460                  * For simple region_fields, we just directly access the owning
 461                  * Operation Region.
 462                  */
 463                 status =
 464                     acpi_ex_access_region(obj_desc, field_datum_byte_offset,
 465                                           value, read_write);
 466                 break;
 467
 468         case ACPI_TYPE_LOCAL_INDEX_FIELD:
 469
 470                 /*
 471                  * Ensure that the index_value is not beyond the capacity of
 472                  * the register
 473                  */
 474                 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
 475                                               (acpi_integer) obj_desc->
 476                                               index_field.value)) {
 477                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
 478                 }
 479
 480                 /* Write the index value to the index_register (itself a region_field) */
 481
 482                 field_datum_byte_offset += obj_desc->index_field.value;
 483
 484                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 485                                   "Write to Index Register: Value %8.8X\n",
 486                                   field_datum_byte_offset));
 487
 488                 status =
 489                     acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
 490                                               &field_datum_byte_offset,
 491                                               sizeof(field_datum_byte_offset));
 492                 if (ACPI_FAILURE(status)) {
 493                         return_ACPI_STATUS(status);
 494                 }
 495
 496                 if (read_write == ACPI_READ) {
 497
 498                         /* Read the datum from the data_register */
 499
 500                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 501                                           "Read from Data Register\n"));
 502
 503                         status =
 504                             acpi_ex_extract_from_field(obj_desc->index_field.
 505                                                        data_obj, value,
 506                                                        sizeof(acpi_integer));
 507                 } else {
 508                         /* Write the datum to the data_register */
 509
 510                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 511                                           "Write to Data Register: Value %8.8X%8.8X\n",
 512                                           ACPI_FORMAT_UINT64(*value)));
 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                             obj_desc->common.type));
 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         u32 required_length;
 809         void *new_buffer;
 810
 811         ACPI_FUNCTION_TRACE(ex_insert_into_field);
 812
 813         /* Validate input buffer */
 814
 815         new_buffer = NULL;
 816         required_length =
 817             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
 818         /*
 819          * We must have a buffer that is at least as long as the field
 820          * we are writing to.  This is because individual fields are
 821          * indivisible and partial writes are not supported -- as per
 822          * the ACPI specification.
 823          */
 824         if (buffer_length < required_length) {
 825
 826                 /* We need to create a new buffer */
 827
 828                 new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
 829                 if (!new_buffer) {
 830                         return_ACPI_STATUS(AE_NO_MEMORY);
 831                 }
 832
 833                 /*
 834                  * Copy the original data to the new buffer, starting
 835                  * at Byte zero.  All unused (upper) bytes of the
 836                  * buffer will be 0.
 837                  */
 838                 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length);
 839                 buffer = new_buffer;
 840                 buffer_length = required_length;
 841         }
 842
 843         /*
 844          * Create the bitmasks used for bit insertion.
 845          * Note: This if/else is used to bypass compiler differences with the
 846          * shift operator
 847          */
 848         if (obj_desc->common_field.access_bit_width == ACPI_INTEGER_BIT_SIZE) {
 849                 width_mask = ACPI_INTEGER_MAX;
 850         } else {
 851                 width_mask =
 852                     ACPI_MASK_BITS_ABOVE(obj_desc->common_field.
 853                                          access_bit_width);
 854         }
 855
 856         mask = width_mask &
 857             ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
 858
 859         /* Compute the number of datums (access width data items) */
 860
 861         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
 862                                        obj_desc->common_field.access_bit_width);
 863
 864         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
 865                                              obj_desc->common_field.
 866                                              start_field_bit_offset,
 867                                              obj_desc->common_field.
 868                                              access_bit_width);
 869
 870         /* Get initial Datum from the input buffer */
 871
 872         ACPI_MEMCPY(&raw_datum, buffer,
 873                     ACPI_MIN(obj_desc->common_field.access_byte_width,
 874                              buffer_length - buffer_offset));
 875
 876         merged_datum =
 877             raw_datum << obj_desc->common_field.start_field_bit_offset;
 878
 879         /* Write the entire field */
 880
 881         for (i = 1; i < field_datum_count; i++) {
 882
 883                 /* Write merged datum to the target field */
 884
 885                 merged_datum &= mask;
 886                 status = acpi_ex_write_with_update_rule(obj_desc, mask,
 887                                                         merged_datum,
 888                                                         field_offset);
 889                 if (ACPI_FAILURE(status)) {
 890                         goto exit;
 891                 }
 892
 893                 field_offset += obj_desc->common_field.access_byte_width;
 894
 895                 /*
 896                  * Start new output datum by merging with previous input datum
 897                  * if necessary.
 898                  *
 899                  * Note: Before the shift, check if the shift value will be larger than
 900                  * the integer size. If so, there is no need to perform the operation.
 901                  * This avoids the differences in behavior between different compilers
 902                  * concerning shift values larger than the target data width.
 903                  */
 904                 if ((obj_desc->common_field.access_bit_width -
 905                      obj_desc->common_field.start_field_bit_offset) <
 906                     ACPI_INTEGER_BIT_SIZE) {
 907                         merged_datum =
 908                             raw_datum >> (obj_desc->common_field.
 909                                           access_bit_width -
 910                                           obj_desc->common_field.
 911                                           start_field_bit_offset);
 912                 } else {
 913                         merged_datum = 0;
 914                 }
 915
 916                 mask = width_mask;
 917
 918                 if (i == datum_count) {
 919                         break;
 920                 }
 921
 922                 /* Get the next input datum from the buffer */
 923
 924                 buffer_offset += obj_desc->common_field.access_byte_width;
 925                 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset,
 926                             ACPI_MIN(obj_desc->common_field.access_byte_width,
 927                                      buffer_length - buffer_offset));
 928                 merged_datum |=
 929                     raw_datum << obj_desc->common_field.start_field_bit_offset;
 930         }
 931
 932         /* Mask off any extra bits in the last datum */
 933
 934         buffer_tail_bits = (obj_desc->common_field.bit_length +
 935                             obj_desc->common_field.start_field_bit_offset) %
 936             obj_desc->common_field.access_bit_width;
 937         if (buffer_tail_bits) {
 938                 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
 939         }
 940
 941         /* Write the last datum to the field */
 942
 943         merged_datum &= mask;
 944         status = acpi_ex_write_with_update_rule(obj_desc,
 945                                                 mask, merged_datum,
 946                                                 field_offset);
 947
 948       exit:
 949         /* Free temporary buffer if we used one */
 950
 951         if (new_buffer) {
 952                 ACPI_FREE(new_buffer);
 953         }
 954         return_ACPI_STATUS(status);
 955 }