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