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

   1 /******************************************************************************
   2  *
   3  * Module Name: exfldio - Aml Field I/O
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2008, Intel Corp.
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions, and the following disclaimer,
  16  *    without modification.
  17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  18  *    substantially similar to the "NO WARRANTY" disclaimer below
  19  *    ("Disclaimer") and any redistribution must be conditioned upon
  20  *    including a substantially similar Disclaimer requirement for further
  21  *    binary redistribution.
  22  * 3. Neither the names of the above-listed copyright holders nor the names
  23  *    of any contributors may be used to endorse or promote products derived
  24  *    from this software without specific prior written permission.
  25  *
  26  * Alternatively, this software may be distributed under the terms of the
  27  * GNU General Public License ("GPL") version 2 as published by the Free
  28  * Software Foundation.
  29  *
  30  * NO WARRANTY
  31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  41  * POSSIBILITY OF SUCH DAMAGES.
  42  */
  43
  44 #include <acpi/acpi.h>
  45 #include <acpi/acinterp.h>
  46 #include <acpi/amlcode.h>
  47 #include <acpi/acevents.h>
  48 #include <acpi/acdispat.h>
  49
  50 #define _COMPONENT          ACPI_EXECUTER
  51 ACPI_MODULE_NAME("exfldio")
  52
  53 /* Local prototypes */
  54 static acpi_status
  55 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
  56                        u32 field_datum_byte_offset,
  57                        acpi_integer * value, u32 read_write);
  58
  59 static u8
  60 acpi_ex_register_overflow(union acpi_operand_object *obj_desc,
  61                           acpi_integer value);
  62
  63 static acpi_status
  64 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
  65                      u32 field_datum_byte_offset);
  66
  67 /*******************************************************************************
  68  *
  69  * FUNCTION:    acpi_ex_setup_region
  70  *
  71  * PARAMETERS:  obj_desc                - Field to be read or written
  72  *              field_datum_byte_offset - Byte offset of this datum within the
  73  *                                        parent field
  74  *
  75  * RETURN:      Status
  76  *
  77  * DESCRIPTION: Common processing for acpi_ex_extract_from_field and
  78  *              acpi_ex_insert_into_field. Initialize the Region if necessary and
  79  *              validate the request.
  80  *
  81  ******************************************************************************/
  82
  83 static acpi_status
  84 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
  85                      u32 field_datum_byte_offset)
  86 {
  87         acpi_status status = AE_OK;
  88         union acpi_operand_object *rgn_desc;
  89
  90         ACPI_FUNCTION_TRACE_U32(ex_setup_region, field_datum_byte_offset);
  91
  92         rgn_desc = obj_desc->common_field.region_obj;
  93
  94         /* We must have a valid region */
  95
  96         if (ACPI_GET_OBJECT_TYPE(rgn_desc) != ACPI_TYPE_REGION) {
  97                 ACPI_ERROR((AE_INFO, "Needed Region, found type %X (%s)",
  98                             ACPI_GET_OBJECT_TYPE(rgn_desc),
  99                             acpi_ut_get_object_type_name(rgn_desc)));
 100
 101                 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
 102         }
 103
 104         /*
 105          * If the Region Address and Length have not been previously evaluated,
 106          * evaluate them now and save the results.
 107          */
 108         if (!(rgn_desc->common.flags & AOPOBJ_DATA_VALID)) {
 109                 status = acpi_ds_get_region_arguments(rgn_desc);
 110                 if (ACPI_FAILURE(status)) {
 111                         return_ACPI_STATUS(status);
 112                 }
 113         }
 114
 115         /* Exit if Address/Length have been disallowed by the host OS */
 116
 117         if (rgn_desc->common.flags & AOPOBJ_INVALID) {
 118                 return_ACPI_STATUS(AE_AML_ILLEGAL_ADDRESS);
 119         }
 120
 121         /*
 122          * Exit now for SMBus address space, it has a non-linear address space
 123          * and the request cannot be directly validated
 124          */
 125         if (rgn_desc->region.space_id == ACPI_ADR_SPACE_SMBUS) {
 126
 127                 /* SMBus has a non-linear address space */
 128
 129                 return_ACPI_STATUS(AE_OK);
 130         }
 131 #ifdef ACPI_UNDER_DEVELOPMENT
 132         /*
 133          * If the Field access is any_acc, we can now compute the optimal
 134          * access (because we know know the length of the parent region)
 135          */
 136         if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 137                 if (ACPI_FAILURE(status)) {
 138                         return_ACPI_STATUS(status);
 139                 }
 140         }
 141 #endif
 142
 143         /*
 144          * Validate the request.  The entire request from the byte offset for a
 145          * length of one field datum (access width) must fit within the region.
 146          * (Region length is specified in bytes)
 147          */
 148         if (rgn_desc->region.length <
 149             (obj_desc->common_field.base_byte_offset +
 150              field_datum_byte_offset +
 151              obj_desc->common_field.access_byte_width)) {
 152                 if (acpi_gbl_enable_interpreter_slack) {
 153                         /*
 154                          * Slack mode only:  We will go ahead and allow access to this
 155                          * field if it is within the region length rounded up to the next
 156                          * access width boundary. acpi_size cast for 64-bit compile.
 157                          */
 158                         if (ACPI_ROUND_UP(rgn_desc->region.length,
 159                                           obj_desc->common_field.
 160                                           access_byte_width) >=
 161                             ((acpi_size) obj_desc->common_field.
 162                              base_byte_offset +
 163                              obj_desc->common_field.access_byte_width +
 164                              field_datum_byte_offset)) {
 165                                 return_ACPI_STATUS(AE_OK);
 166                         }
 167                 }
 168
 169                 if (rgn_desc->region.length <
 170                     obj_desc->common_field.access_byte_width) {
 171                         /*
 172                          * This is the case where the access_type (acc_word, etc.) is wider
 173                          * than the region itself.  For example, a region of length one
 174                          * byte, and a field with Dword access specified.
 175                          */
 176                         ACPI_ERROR((AE_INFO,
 177                                     "Field [%4.4s] access width (%d bytes) too large for region [%4.4s] (length %X)",
 178                                     acpi_ut_get_node_name(obj_desc->
 179                                                           common_field.node),
 180                                     obj_desc->common_field.access_byte_width,
 181                                     acpi_ut_get_node_name(rgn_desc->region.
 182                                                           node),
 183                                     rgn_desc->region.length));
 184                 }
 185
 186                 /*
 187                  * Offset rounded up to next multiple of field width
 188                  * exceeds region length, indicate an error
 189                  */
 190                 ACPI_ERROR((AE_INFO,
 191                             "Field [%4.4s] Base+Offset+Width %X+%X+%X is beyond end of region [%4.4s] (length %X)",
 192                             acpi_ut_get_node_name(obj_desc->common_field.node),
 193                             obj_desc->common_field.base_byte_offset,
 194                             field_datum_byte_offset,
 195                             obj_desc->common_field.access_byte_width,
 196                             acpi_ut_get_node_name(rgn_desc->region.node),
 197                             rgn_desc->region.length));
 198
 199                 return_ACPI_STATUS(AE_AML_REGION_LIMIT);
 200         }
 201
 202         return_ACPI_STATUS(AE_OK);
 203 }
 204
 205 /*******************************************************************************
 206  *
 207  * FUNCTION:    acpi_ex_access_region
 208  *
 209  * PARAMETERS:  obj_desc                - Field to be read
 210  *              field_datum_byte_offset - Byte offset of this datum within the
 211  *                                        parent field
 212  *              Value                   - Where to store value (must at least
 213  *                                        the size of acpi_integer)
 214  *              Function                - Read or Write flag plus other region-
 215  *                                        dependent flags
 216  *
 217  * RETURN:      Status
 218  *
 219  * DESCRIPTION: Read or Write a single field datum to an Operation Region.
 220  *
 221  ******************************************************************************/
 222
 223 acpi_status
 224 acpi_ex_access_region(union acpi_operand_object *obj_desc,
 225                       u32 field_datum_byte_offset,
 226                       acpi_integer * value, u32 function)
 227 {
 228         acpi_status status;
 229         union acpi_operand_object *rgn_desc;
 230         acpi_physical_address address;
 231
 232         ACPI_FUNCTION_TRACE(ex_access_region);
 233
 234         /*
 235          * Ensure that the region operands are fully evaluated and verify
 236          * the validity of the request
 237          */
 238         status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset);
 239         if (ACPI_FAILURE(status)) {
 240                 return_ACPI_STATUS(status);
 241         }
 242
 243         /*
 244          * The physical address of this field datum is:
 245          *
 246          * 1) The base of the region, plus
 247          * 2) The base offset of the field, plus
 248          * 3) The current offset into the field
 249          */
 250         rgn_desc = obj_desc->common_field.region_obj;
 251         address = rgn_desc->region.address +
 252             obj_desc->common_field.base_byte_offset + field_datum_byte_offset;
 253
 254         if ((function & ACPI_IO_MASK) == ACPI_READ) {
 255                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
 256         } else {
 257                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
 258         }
 259
 260         ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
 261                               " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n",
 262                               acpi_ut_get_region_name(rgn_desc->region.
 263                                                       space_id),
 264                               rgn_desc->region.space_id,
 265                               obj_desc->common_field.access_byte_width,
 266                               obj_desc->common_field.base_byte_offset,
 267                               field_datum_byte_offset, ACPI_CAST_PTR(void,
 268                                                                      address)));
 269
 270         /* Invoke the appropriate address_space/op_region handler */
 271
 272         status = acpi_ev_address_space_dispatch(rgn_desc, function,
 273                                                 address,
 274                                                 ACPI_MUL_8(obj_desc->
 275                                                            common_field.
 276                                                            access_byte_width),
 277                                                 value);
 278
 279         if (ACPI_FAILURE(status)) {
 280                 if (status == AE_NOT_IMPLEMENTED) {
 281                         ACPI_ERROR((AE_INFO,
 282                                     "Region %s(%X) not implemented",
 283                                     acpi_ut_get_region_name(rgn_desc->region.
 284                                                             space_id),
 285                                     rgn_desc->region.space_id));
 286                 } else if (status == AE_NOT_EXIST) {
 287                         ACPI_ERROR((AE_INFO,
 288                                     "Region %s(%X) has no handler",
 289                                     acpi_ut_get_region_name(rgn_desc->region.
 290                                                             space_id),
 291                                     rgn_desc->region.space_id));
 292                 }
 293         }
 294
 295         return_ACPI_STATUS(status);
 296 }
 297
 298 /*******************************************************************************
 299  *
 300  * FUNCTION:    acpi_ex_register_overflow
 301  *
 302  * PARAMETERS:  obj_desc                - Register(Field) to be written
 303  *              Value                   - Value to be stored
 304  *
 305  * RETURN:      TRUE if value overflows the field, FALSE otherwise
 306  *
 307  * DESCRIPTION: Check if a value is out of range of the field being written.
 308  *              Used to check if the values written to Index and Bank registers
 309  *              are out of range.  Normally, the value is simply truncated
 310  *              to fit the field, but this case is most likely a serious
 311  *              coding error in the ASL.
 312  *
 313  ******************************************************************************/
 314
 315 static u8
 316 acpi_ex_register_overflow(union acpi_operand_object *obj_desc,
 317                           acpi_integer value)
 318 {
 319
 320         if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
 321                 /*
 322                  * The field is large enough to hold the maximum integer, so we can
 323                  * never overflow it.
 324                  */
 325                 return (FALSE);
 326         }
 327
 328         if (value >= ((acpi_integer) 1 << obj_desc->common_field.bit_length)) {
 329                 /*
 330                  * The Value is larger than the maximum value that can fit into
 331                  * the register.
 332                  */
 333                 return (TRUE);
 334         }
 335
 336         /* The Value will fit into the field with no truncation */
 337
 338         return (FALSE);
 339 }
 340
 341 /*******************************************************************************
 342  *
 343  * FUNCTION:    acpi_ex_field_datum_io
 344  *
 345  * PARAMETERS:  obj_desc                - Field to be read
 346  *              field_datum_byte_offset - Byte offset of this datum within the
 347  *                                        parent field
 348  *              Value                   - Where to store value (must be 64 bits)
 349  *              read_write              - Read or Write flag
 350  *
 351  * RETURN:      Status
 352  *
 353  * DESCRIPTION: Read or Write a single datum of a field.  The field_type is
 354  *              demultiplexed here to handle the different types of fields
 355  *              (buffer_field, region_field, index_field, bank_field)
 356  *
 357  ******************************************************************************/
 358
 359 static acpi_status
 360 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
 361                        u32 field_datum_byte_offset,
 362                        acpi_integer * value, u32 read_write)
 363 {
 364         acpi_status status;
 365         acpi_integer local_value;
 366
 367         ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
 368
 369         if (read_write == ACPI_READ) {
 370                 if (!value) {
 371                         local_value = 0;
 372
 373                         /* To support reads without saving return value */
 374                         value = &local_value;
 375                 }
 376
 377                 /* Clear the entire return buffer first, [Very Important!] */
 378
 379                 *value = 0;
 380         }
 381
 382         /*
 383          * The four types of fields are:
 384          *
 385          * buffer_field - Read/write from/to a Buffer
 386          * region_field - Read/write from/to a Operation Region.
 387          * bank_field  - Write to a Bank Register, then read/write from/to an
 388          *               operation_region
 389          * index_field - Write to an Index Register, then read/write from/to a
 390          *               Data Register
 391          */
 392         switch (ACPI_GET_OBJECT_TYPE(obj_desc)) {
 393         case ACPI_TYPE_BUFFER_FIELD:
 394                 /*
 395                  * If the buffer_field arguments have not been previously evaluated,
 396                  * evaluate them now and save the results.
 397                  */
 398                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 399                         status = acpi_ds_get_buffer_field_arguments(obj_desc);
 400                         if (ACPI_FAILURE(status)) {
 401                                 return_ACPI_STATUS(status);
 402                         }
 403                 }
 404
 405                 if (read_write == ACPI_READ) {
 406                         /*
 407                          * Copy the data from the source buffer.
 408                          * Length is the field width in bytes.
 409                          */
 410                         ACPI_MEMCPY(value,
 411                                     (obj_desc->buffer_field.buffer_obj)->buffer.
 412                                     pointer +
 413                                     obj_desc->buffer_field.base_byte_offset +
 414                                     field_datum_byte_offset,
 415                                     obj_desc->common_field.access_byte_width);
 416                 } else {
 417                         /*
 418                          * Copy the data to the target buffer.
 419                          * Length is the field width in bytes.
 420                          */
 421                         ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer.
 422                                     pointer +
 423                                     obj_desc->buffer_field.base_byte_offset +
 424                                     field_datum_byte_offset, value,
 425                                     obj_desc->common_field.access_byte_width);
 426                 }
 427
 428                 status = AE_OK;
 429                 break;
 430
 431         case ACPI_TYPE_LOCAL_BANK_FIELD:
 432
 433                 /*
 434                  * Ensure that the bank_value is not beyond the capacity of
 435                  * the register
 436                  */
 437                 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
 438                                               (acpi_integer) obj_desc->
 439                                               bank_field.value)) {
 440                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
 441                 }
 442
 443                 /*
 444                  * For bank_fields, we must write the bank_value to the bank_register
 445                  * (itself a region_field) before we can access the data.
 446                  */
 447                 status =
 448                     acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
 449                                               &obj_desc->bank_field.value,
 450                                               sizeof(obj_desc->bank_field.
 451                                                      value));
 452                 if (ACPI_FAILURE(status)) {
 453                         return_ACPI_STATUS(status);
 454                 }
 455
 456                 /*
 457                  * Now that the Bank has been selected, fall through to the
 458                  * region_field case and write the datum to the Operation Region
 459                  */
 460
 461                 /*lint -fallthrough */
 462
 463         case ACPI_TYPE_LOCAL_REGION_FIELD:
 464                 /*
 465                  * For simple region_fields, we just directly access the owning
 466                  * Operation Region.
 467                  */
 468                 status =
 469                     acpi_ex_access_region(obj_desc, field_datum_byte_offset,
 470                                           value, read_write);
 471                 break;
 472
 473         case ACPI_TYPE_LOCAL_INDEX_FIELD:
 474
 475                 /*
 476                  * Ensure that the index_value is not beyond the capacity of
 477                  * the register
 478                  */
 479                 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
 480                                               (acpi_integer) obj_desc->
 481                                               index_field.value)) {
 482                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
 483                 }
 484
 485                 /* Write the index value to the index_register (itself a region_field) */
 486
 487                 field_datum_byte_offset += obj_desc->index_field.value;
 488
 489                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 490                                   "Write to Index Register: Value %8.8X\n",
 491                                   field_datum_byte_offset));
 492
 493                 status =
 494                     acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
 495                                               &field_datum_byte_offset,
 496                                               sizeof(field_datum_byte_offset));
 497                 if (ACPI_FAILURE(status)) {
 498                         return_ACPI_STATUS(status);
 499                 }
 500
 501                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 502                                   "I/O to Data Register: ValuePtr %p\n",
 503                                   value));
 504
 505                 if (read_write == ACPI_READ) {
 506
 507                         /* Read the datum from the data_register */
 508
 509                         status =
 510                             acpi_ex_extract_from_field(obj_desc->index_field.
 511                                                        data_obj, value,
 512                                                        sizeof(acpi_integer));
 513                 } else {
 514                         /* Write the datum to the data_register */
 515
 516                         status =
 517                             acpi_ex_insert_into_field(obj_desc->index_field.
 518                                                       data_obj, value,
 519                                                       sizeof(acpi_integer));
 520                 }
 521                 break;
 522
 523         default:
 524
 525                 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %X",
 526                             ACPI_GET_OBJECT_TYPE(obj_desc)));
 527                 status = AE_AML_INTERNAL;
 528                 break;
 529         }
 530
 531         if (ACPI_SUCCESS(status)) {
 532                 if (read_write == ACPI_READ) {
 533                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 534                                           "Value Read %8.8X%8.8X, Width %d\n",
 535                                           ACPI_FORMAT_UINT64(*value),
 536                                           obj_desc->common_field.
 537                                           access_byte_width));
 538                 } else {
 539                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 540                                           "Value Written %8.8X%8.8X, Width %d\n",
 541                                           ACPI_FORMAT_UINT64(*value),
 542                                           obj_desc->common_field.
 543                                           access_byte_width));
 544                 }
 545         }
 546
 547         return_ACPI_STATUS(status);
 548 }
 549
 550 /*******************************************************************************
 551  *
 552  * FUNCTION:    acpi_ex_write_with_update_rule
 553  *
 554  * PARAMETERS:  obj_desc                - Field to be written
 555  *              Mask                    - bitmask within field datum
 556  *              field_value             - Value to write
 557  *              field_datum_byte_offset - Offset of datum within field
 558  *
 559  * RETURN:      Status
 560  *
 561  * DESCRIPTION: Apply the field update rule to a field write
 562  *
 563  ******************************************************************************/
 564
 565 acpi_status
 566 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc,
 567                                acpi_integer mask,
 568                                acpi_integer field_value,
 569                                u32 field_datum_byte_offset)
 570 {
 571         acpi_status status = AE_OK;
 572         acpi_integer merged_value;
 573         acpi_integer current_value;
 574
 575         ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask);
 576
 577         /* Start with the new bits  */
 578
 579         merged_value = field_value;
 580
 581         /* If the mask is all ones, we don't need to worry about the update rule */
 582
 583         if (mask != ACPI_INTEGER_MAX) {
 584
 585                 /* Decode the update rule */
 586
 587                 switch (obj_desc->common_field.
 588                         field_flags & AML_FIELD_UPDATE_RULE_MASK) {
 589                 case AML_FIELD_UPDATE_PRESERVE:
 590                         /*
 591                          * Check if update rule needs to be applied (not if mask is all
 592                          * ones)  The left shift drops the bits we want to ignore.
 593                          */
 594                         if ((~mask << (ACPI_MUL_8(sizeof(mask)) -
 595                                        ACPI_MUL_8(obj_desc->common_field.
 596                                                   access_byte_width))) != 0) {
 597                                 /*
 598                                  * Read the current contents of the byte/word/dword containing
 599                                  * the field, and merge with the new field value.
 600                                  */
 601                                 status =
 602                                     acpi_ex_field_datum_io(obj_desc,
 603                                                            field_datum_byte_offset,
 604                                                            &current_value,
 605                                                            ACPI_READ);
 606                                 if (ACPI_FAILURE(status)) {
 607                                         return_ACPI_STATUS(status);
 608                                 }
 609
 610                                 merged_value |= (current_value & ~mask);
 611                         }
 612                         break;
 613
 614                 case AML_FIELD_UPDATE_WRITE_AS_ONES:
 615
 616                         /* Set positions outside the field to all ones */
 617
 618                         merged_value |= ~mask;
 619                         break;
 620
 621                 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
 622
 623                         /* Set positions outside the field to all zeros */
 624
 625                         merged_value &= mask;
 626                         break;
 627
 628                 default:
 629
 630                         ACPI_ERROR((AE_INFO,
 631                                     "Unknown UpdateRule value: %X",
 632                                     (obj_desc->common_field.
 633                                      field_flags &
 634                                      AML_FIELD_UPDATE_RULE_MASK)));
 635                         return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
 636                 }
 637         }
 638
 639         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 640                           "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
 641                           ACPI_FORMAT_UINT64(mask),
 642                           field_datum_byte_offset,
 643                           obj_desc->common_field.access_byte_width,
 644                           ACPI_FORMAT_UINT64(field_value),
 645                           ACPI_FORMAT_UINT64(merged_value)));
 646
 647         /* Write the merged value */
 648
 649         status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset,
 650                                         &merged_value, ACPI_WRITE);
 651
 652         return_ACPI_STATUS(status);
 653 }
 654
 655 /*******************************************************************************
 656  *
 657  * FUNCTION:    acpi_ex_extract_from_field
 658  *
 659  * PARAMETERS:  obj_desc            - Field to be read
 660  *              Buffer              - Where to store the field data
 661  *              buffer_length       - Length of Buffer
 662  *
 663  * RETURN:      Status
 664  *
 665  * DESCRIPTION: Retrieve the current value of the given field
 666  *
 667  ******************************************************************************/
 668
 669 acpi_status
 670 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
 671                            void *buffer, u32 buffer_length)
 672 {
 673         acpi_status status;
 674         acpi_integer raw_datum;
 675         acpi_integer merged_datum;
 676         u32 field_offset = 0;
 677         u32 buffer_offset = 0;
 678         u32 buffer_tail_bits;
 679         u32 datum_count;
 680         u32 field_datum_count;
 681         u32 i;
 682
 683         ACPI_FUNCTION_TRACE(ex_extract_from_field);
 684
 685         /* Validate target buffer and clear it */
 686
 687         if (buffer_length <
 688             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
 689                 ACPI_ERROR((AE_INFO,
 690                             "Field size %X (bits) is too large for buffer (%X)",
 691                             obj_desc->common_field.bit_length, buffer_length));
 692
 693                 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
 694         }
 695         ACPI_MEMSET(buffer, 0, buffer_length);
 696
 697         /* Compute the number of datums (access width data items) */
 698
 699         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
 700                                        obj_desc->common_field.access_bit_width);
 701         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
 702                                              obj_desc->common_field.
 703                                              start_field_bit_offset,
 704                                              obj_desc->common_field.
 705                                              access_bit_width);
 706
 707         /* Priming read from the field */
 708
 709         status =
 710             acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
 711                                    ACPI_READ);
 712         if (ACPI_FAILURE(status)) {
 713                 return_ACPI_STATUS(status);
 714         }
 715         merged_datum =
 716             raw_datum >> obj_desc->common_field.start_field_bit_offset;
 717
 718         /* Read the rest of the field */
 719
 720         for (i = 1; i < field_datum_count; i++) {
 721
 722                 /* Get next input datum from the field */
 723
 724                 field_offset += obj_desc->common_field.access_byte_width;
 725                 status = acpi_ex_field_datum_io(obj_desc, field_offset,
 726                                                 &raw_datum, ACPI_READ);
 727                 if (ACPI_FAILURE(status)) {
 728                         return_ACPI_STATUS(status);
 729                 }
 730
 731                 /*
 732                  * Merge with previous datum if necessary.
 733                  *
 734                  * Note: Before the shift, check if the shift value will be larger than
 735                  * the integer size. If so, there is no need to perform the operation.
 736                  * This avoids the differences in behavior between different compilers
 737                  * concerning shift values larger than the target data width.
 738                  */
 739                 if ((obj_desc->common_field.access_bit_width -
 740                      obj_desc->common_field.start_field_bit_offset) <
 741                     ACPI_INTEGER_BIT_SIZE) {
 742                         merged_datum |=
 743                             raw_datum << (obj_desc->common_field.
 744                                           access_bit_width -
 745                                           obj_desc->common_field.
 746                                           start_field_bit_offset);
 747                 }
 748
 749                 if (i == datum_count) {
 750                         break;
 751                 }
 752
 753                 /* Write merged datum to target buffer */
 754
 755                 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
 756                             ACPI_MIN(obj_desc->common_field.access_byte_width,
 757                                      buffer_length - buffer_offset));
 758
 759                 buffer_offset += obj_desc->common_field.access_byte_width;
 760                 merged_datum =
 761                     raw_datum >> obj_desc->common_field.start_field_bit_offset;
 762         }
 763
 764         /* Mask off any extra bits in the last datum */
 765
 766         buffer_tail_bits = obj_desc->common_field.bit_length %
 767             obj_desc->common_field.access_bit_width;
 768         if (buffer_tail_bits) {
 769                 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
 770         }
 771
 772         /* Write the last datum to the buffer */
 773
 774         ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
 775                     ACPI_MIN(obj_desc->common_field.access_byte_width,
 776                              buffer_length - buffer_offset));
 777
 778         return_ACPI_STATUS(AE_OK);
 779 }
 780
 781 /*******************************************************************************
 782  *
 783  * FUNCTION:    acpi_ex_insert_into_field
 784  *
 785  * PARAMETERS:  obj_desc            - Field to be written
 786  *              Buffer              - Data to be written
 787  *              buffer_length       - Length of Buffer
 788  *
 789  * RETURN:      Status
 790  *
 791  * DESCRIPTION: Store the Buffer contents into the given field
 792  *
 793  ******************************************************************************/
 794
 795 acpi_status
 796 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
 797                           void *buffer, u32 buffer_length)
 798 {
 799         acpi_status status;
 800         acpi_integer mask;
 801         acpi_integer width_mask;
 802         acpi_integer merged_datum;
 803         acpi_integer raw_datum = 0;
 804         u32 field_offset = 0;
 805         u32 buffer_offset = 0;
 806         u32 buffer_tail_bits;
 807         u32 datum_count;
 808         u32 field_datum_count;
 809         u32 i;
 810         u32 required_length;
 811         void *new_buffer;
 812
 813         ACPI_FUNCTION_TRACE(ex_insert_into_field);
 814
 815         /* Validate input buffer */
 816
 817         new_buffer = NULL;
 818         required_length =
 819             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
 820         /*
 821          * We must have a buffer that is at least as long as the field
 822          * we are writing to.  This is because individual fields are
 823          * indivisible and partial writes are not supported -- as per
 824          * the ACPI specification.
 825          */
 826         if (buffer_length < required_length) {
 827
 828                 /* We need to create a new buffer */
 829
 830                 new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
 831                 if (!new_buffer) {
 832                         return_ACPI_STATUS(AE_NO_MEMORY);
 833                 }
 834
 835                 /*
 836                  * Copy the original data to the new buffer, starting
 837                  * at Byte zero.  All unused (upper) bytes of the
 838                  * buffer will be 0.
 839                  */
 840                 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length);
 841                 buffer = new_buffer;
 842                 buffer_length = required_length;
 843         }
 844
 845         /*
 846          * Create the bitmasks used for bit insertion.
 847          * Note: This if/else is used to bypass compiler differences with the
 848          * shift operator
 849          */
 850         if (obj_desc->common_field.access_bit_width == ACPI_INTEGER_BIT_SIZE) {
 851                 width_mask = ACPI_INTEGER_MAX;
 852         } else {
 853                 width_mask =
 854                     ACPI_MASK_BITS_ABOVE(obj_desc->common_field.
 855                                          access_bit_width);
 856         }
 857
 858         mask = width_mask &
 859             ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
 860
 861         /* Compute the number of datums (access width data items) */
 862
 863         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
 864                                        obj_desc->common_field.access_bit_width);
 865
 866         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
 867                                              obj_desc->common_field.
 868                                              start_field_bit_offset,
 869                                              obj_desc->common_field.
 870                                              access_bit_width);
 871
 872         /* Get initial Datum from the input buffer */
 873
 874         ACPI_MEMCPY(&raw_datum, buffer,
 875                     ACPI_MIN(obj_desc->common_field.access_byte_width,
 876                              buffer_length - buffer_offset));
 877
 878         merged_datum =
 879             raw_datum << obj_desc->common_field.start_field_bit_offset;
 880
 881         /* Write the entire field */
 882
 883         for (i = 1; i < field_datum_count; i++) {
 884
 885                 /* Write merged datum to the target field */
 886
 887                 merged_datum &= mask;
 888                 status = acpi_ex_write_with_update_rule(obj_desc, mask,
 889                                                         merged_datum,
 890                                                         field_offset);
 891                 if (ACPI_FAILURE(status)) {
 892                         goto exit;
 893                 }
 894
 895                 field_offset += obj_desc->common_field.access_byte_width;
 896
 897                 /*
 898                  * Start new output datum by merging with previous input datum
 899                  * if necessary.
 900                  *
 901                  * Note: Before the shift, check if the shift value will be larger than
 902                  * the integer size. If so, there is no need to perform the operation.
 903                  * This avoids the differences in behavior between different compilers
 904                  * concerning shift values larger than the target data width.
 905                  */
 906                 if ((obj_desc->common_field.access_bit_width -
 907                      obj_desc->common_field.start_field_bit_offset) <
 908                     ACPI_INTEGER_BIT_SIZE) {
 909                         merged_datum =
 910                             raw_datum >> (obj_desc->common_field.
 911                                           access_bit_width -
 912                                           obj_desc->common_field.
 913                                           start_field_bit_offset);
 914                 } else {
 915                         merged_datum = 0;
 916                 }
 917
 918                 mask = width_mask;
 919
 920                 if (i == datum_count) {
 921                         break;
 922                 }
 923
 924                 /* Get the next input datum from the buffer */
 925
 926                 buffer_offset += obj_desc->common_field.access_byte_width;
 927                 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset,
 928                             ACPI_MIN(obj_desc->common_field.access_byte_width,
 929                                      buffer_length - buffer_offset));
 930                 merged_datum |=
 931                     raw_datum << obj_desc->common_field.start_field_bit_offset;
 932         }
 933
 934         /* Mask off any extra bits in the last datum */
 935
 936         buffer_tail_bits = (obj_desc->common_field.bit_length +
 937                             obj_desc->common_field.start_field_bit_offset) %
 938             obj_desc->common_field.access_bit_width;
 939         if (buffer_tail_bits) {
 940                 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
 941         }
 942
 943         /* Write the last datum to the field */
 944
 945         merged_datum &= mask;
 946         status = acpi_ex_write_with_update_rule(obj_desc,
 947                                                 mask, merged_datum,
 948                                                 field_offset);
 949
 950       exit:
 951         /* Free temporary buffer if we used one */
 952
 953         if (new_buffer) {
 954                 ACPI_FREE(new_buffer);
 955         }
 956         return_ACPI_STATUS(status);
 957 }