drivers/acpi/acpica/exfldio.c

   1 /******************************************************************************
   2  *
   3  * Module Name: exfldio - Aml Field I/O
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2011, 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                        u64 *value, u32 read_write);
  59
  60 static u8
  61 acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 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 (rgn_desc->common.type != ACPI_TYPE_REGION) {
  97                 ACPI_ERROR((AE_INFO, "Needed Region, found type 0x%X (%s)",
  98                             rgn_desc->common.type,
  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 or IPMI address space, it has a non-linear
 123          * address space and the request cannot be directly validated
 124          */
 125         if (rgn_desc->region.space_id == ACPI_ADR_SPACE_SMBUS ||
 126             rgn_desc->region.space_id == ACPI_ADR_SPACE_IPMI) {
 127
 128                 /* SMBus or IPMI has a non-linear address space */
 129
 130                 return_ACPI_STATUS(AE_OK);
 131         }
 132 #ifdef ACPI_UNDER_DEVELOPMENT
 133         /*
 134          * If the Field access is any_acc, we can now compute the optimal
 135          * access (because we know know the length of the parent region)
 136          */
 137         if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 138                 if (ACPI_FAILURE(status)) {
 139                         return_ACPI_STATUS(status);
 140                 }
 141         }
 142 #endif
 143
 144         /*
 145          * Validate the request.  The entire request from the byte offset for a
 146          * length of one field datum (access width) must fit within the region.
 147          * (Region length is specified in bytes)
 148          */
 149         if (rgn_desc->region.length <
 150             (obj_desc->common_field.base_byte_offset + 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 (%u bytes) too large for region [%4.4s] (length %u)",
 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 %u+%u+%u is beyond end of region [%4.4s] (length %u)",
 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  *                                        64 bits)
 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, u64 *value, u32 function)
 226 {
 227         acpi_status status;
 228         union acpi_operand_object *rgn_desc;
 229         u32 region_offset;
 230
 231         ACPI_FUNCTION_TRACE(ex_access_region);
 232
 233         /*
 234          * Ensure that the region operands are fully evaluated and verify
 235          * the validity of the request
 236          */
 237         status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset);
 238         if (ACPI_FAILURE(status)) {
 239                 return_ACPI_STATUS(status);
 240         }
 241
 242         /*
 243          * The physical address of this field datum is:
 244          *
 245          * 1) The base of the region, plus
 246          * 2) The base offset of the field, plus
 247          * 3) The current offset into the field
 248          */
 249         rgn_desc = obj_desc->common_field.region_obj;
 250         region_offset =
 251             obj_desc->common_field.base_byte_offset + field_datum_byte_offset;
 252
 253         if ((function & ACPI_IO_MASK) == ACPI_READ) {
 254                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
 255         } else {
 256                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
 257         }
 258
 259         ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
 260                               " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n",
 261                               acpi_ut_get_region_name(rgn_desc->region.
 262                                                       space_id),
 263                               rgn_desc->region.space_id,
 264                               obj_desc->common_field.access_byte_width,
 265                               obj_desc->common_field.base_byte_offset,
 266                               field_datum_byte_offset, ACPI_CAST_PTR(void,
 267                                                                      (rgn_desc->
 268                                                                       region.
 269                                                                       address +
 270                                                                       region_offset))));
 271
 272         /* Invoke the appropriate address_space/op_region handler */
 273
 274         status =
 275             acpi_ev_address_space_dispatch(rgn_desc, function, region_offset,
 276                                            ACPI_MUL_8(obj_desc->common_field.
 277                                                       access_byte_width),
 278                                            value);
 279
 280         if (ACPI_FAILURE(status)) {
 281                 if (status == AE_NOT_IMPLEMENTED) {
 282                         ACPI_ERROR((AE_INFO,
 283                                     "Region %s (ID=%u) not implemented",
 284                                     acpi_ut_get_region_name(rgn_desc->region.
 285                                                             space_id),
 286                                     rgn_desc->region.space_id));
 287                 } else if (status == AE_NOT_EXIST) {
 288                         ACPI_ERROR((AE_INFO,
 289                                     "Region %s (ID=%u) has no handler",
 290                                     acpi_ut_get_region_name(rgn_desc->region.
 291                                                             space_id),
 292                                     rgn_desc->region.space_id));
 293                 }
 294         }
 295
 296         return_ACPI_STATUS(status);
 297 }
 298
 299 /*******************************************************************************
 300  *
 301  * FUNCTION:    acpi_ex_register_overflow
 302  *
 303  * PARAMETERS:  obj_desc                - Register(Field) to be written
 304  *              Value                   - Value to be stored
 305  *
 306  * RETURN:      TRUE if value overflows the field, FALSE otherwise
 307  *
 308  * DESCRIPTION: Check if a value is out of range of the field being written.
 309  *              Used to check if the values written to Index and Bank registers
 310  *              are out of range.  Normally, the value is simply truncated
 311  *              to fit the field, but this case is most likely a serious
 312  *              coding error in the ASL.
 313  *
 314  ******************************************************************************/
 315
 316 static u8
 317 acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 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 >= ((u64) 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, u64 *value, u32 read_write)
 362 {
 363         acpi_status status;
 364         u64 local_value;
 365
 366         ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
 367
 368         if (read_write == ACPI_READ) {
 369                 if (!value) {
 370                         local_value = 0;
 371
 372                         /* To support reads without saving return value */
 373                         value = &local_value;
 374                 }
 375
 376                 /* Clear the entire return buffer first, [Very Important!] */
 377
 378                 *value = 0;
 379         }
 380
 381         /*
 382          * The four types of fields are:
 383          *
 384          * buffer_field - Read/write from/to a Buffer
 385          * region_field - Read/write from/to a Operation Region.
 386          * bank_field  - Write to a Bank Register, then read/write from/to an
 387          *               operation_region
 388          * index_field - Write to an Index Register, then read/write from/to a
 389          *               Data Register
 390          */
 391         switch (obj_desc->common.type) {
 392         case ACPI_TYPE_BUFFER_FIELD:
 393                 /*
 394                  * If the buffer_field arguments have not been previously evaluated,
 395                  * evaluate them now and save the results.
 396                  */
 397                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 398                         status = acpi_ds_get_buffer_field_arguments(obj_desc);
 399                         if (ACPI_FAILURE(status)) {
 400                                 return_ACPI_STATUS(status);
 401                         }
 402                 }
 403
 404                 if (read_write == ACPI_READ) {
 405                         /*
 406                          * Copy the data from the source buffer.
 407                          * Length is the field width in bytes.
 408                          */
 409                         ACPI_MEMCPY(value,
 410                                     (obj_desc->buffer_field.buffer_obj)->buffer.
 411                                     pointer +
 412                                     obj_desc->buffer_field.base_byte_offset +
 413                                     field_datum_byte_offset,
 414                                     obj_desc->common_field.access_byte_width);
 415                 } else {
 416                         /*
 417                          * Copy the data to the target buffer.
 418                          * Length is the field width in bytes.
 419                          */
 420                         ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer.
 421                                     pointer +
 422                                     obj_desc->buffer_field.base_byte_offset +
 423                                     field_datum_byte_offset, value,
 424                                     obj_desc->common_field.access_byte_width);
 425                 }
 426
 427                 status = AE_OK;
 428                 break;
 429
 430         case ACPI_TYPE_LOCAL_BANK_FIELD:
 431
 432                 /*
 433                  * Ensure that the bank_value is not beyond the capacity of
 434                  * the register
 435                  */
 436                 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
 437                                               (u64) obj_desc->bank_field.
 438                                               value)) {
 439                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
 440                 }
 441
 442                 /*
 443                  * For bank_fields, we must write the bank_value to the bank_register
 444                  * (itself a region_field) before we can access the data.
 445                  */
 446                 status =
 447                     acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
 448                                               &obj_desc->bank_field.value,
 449                                               sizeof(obj_desc->bank_field.
 450                                                      value));
 451                 if (ACPI_FAILURE(status)) {
 452                         return_ACPI_STATUS(status);
 453                 }
 454
 455                 /*
 456                  * Now that the Bank has been selected, fall through to the
 457                  * region_field case and write the datum to the Operation Region
 458                  */
 459
 460                 /*lint -fallthrough */
 461
 462         case ACPI_TYPE_LOCAL_REGION_FIELD:
 463                 /*
 464                  * For simple region_fields, we just directly access the owning
 465                  * Operation Region.
 466                  */
 467                 status =
 468                     acpi_ex_access_region(obj_desc, field_datum_byte_offset,
 469                                           value, read_write);
 470                 break;
 471
 472         case ACPI_TYPE_LOCAL_INDEX_FIELD:
 473
 474                 /*
 475                  * Ensure that the index_value is not beyond the capacity of
 476                  * the register
 477                  */
 478                 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
 479                                               (u64) obj_desc->index_field.
 480                                               value)) {
 481                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
 482                 }
 483
 484                 /* Write the index value to the index_register (itself a region_field) */
 485
 486                 field_datum_byte_offset += obj_desc->index_field.value;
 487
 488                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 489                                   "Write to Index Register: Value %8.8X\n",
 490                                   field_datum_byte_offset));
 491
 492                 status =
 493                     acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
 494                                               &field_datum_byte_offset,
 495                                               sizeof(field_datum_byte_offset));
 496                 if (ACPI_FAILURE(status)) {
 497                         return_ACPI_STATUS(status);
 498                 }
 499
 500                 if (read_write == ACPI_READ) {
 501
 502                         /* Read the datum from the data_register */
 503
 504                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 505                                           "Read from Data Register\n"));
 506
 507                         status =
 508                             acpi_ex_extract_from_field(obj_desc->index_field.
 509                                                        data_obj, value,
 510                                                        sizeof(u64));
 511                 } else {
 512                         /* Write the datum to the data_register */
 513
 514                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 515                                           "Write to Data Register: Value %8.8X%8.8X\n",
 516                                           ACPI_FORMAT_UINT64(*value)));
 517
 518                         status =
 519                             acpi_ex_insert_into_field(obj_desc->index_field.
 520                                                       data_obj, value,
 521                                                       sizeof(u64));
 522                 }
 523                 break;
 524
 525         default:
 526
 527                 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %u",
 528                             obj_desc->common.type));
 529                 status = AE_AML_INTERNAL;
 530                 break;
 531         }
 532
 533         if (ACPI_SUCCESS(status)) {
 534                 if (read_write == ACPI_READ) {
 535                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 536                                           "Value Read %8.8X%8.8X, Width %u\n",
 537                                           ACPI_FORMAT_UINT64(*value),
 538                                           obj_desc->common_field.
 539                                           access_byte_width));
 540                 } else {
 541                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 542                                           "Value Written %8.8X%8.8X, Width %u\n",
 543                                           ACPI_FORMAT_UINT64(*value),
 544                                           obj_desc->common_field.
 545                                           access_byte_width));
 546                 }
 547         }
 548
 549         return_ACPI_STATUS(status);
 550 }
 551
 552 /*******************************************************************************
 553  *
 554  * FUNCTION:    acpi_ex_write_with_update_rule
 555  *
 556  * PARAMETERS:  obj_desc                - Field to be written
 557  *              Mask                    - bitmask within field datum
 558  *              field_value             - Value to write
 559  *              field_datum_byte_offset - Offset of datum within field
 560  *
 561  * RETURN:      Status
 562  *
 563  * DESCRIPTION: Apply the field update rule to a field write
 564  *
 565  ******************************************************************************/
 566
 567 acpi_status
 568 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc,
 569                                u64 mask,
 570                                u64 field_value, u32 field_datum_byte_offset)
 571 {
 572         acpi_status status = AE_OK;
 573         u64 merged_value;
 574         u64 current_value;
 575
 576         ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask);
 577
 578         /* Start with the new bits  */
 579
 580         merged_value = field_value;
 581
 582         /* If the mask is all ones, we don't need to worry about the update rule */
 583
 584         if (mask != ACPI_UINT64_MAX) {
 585
 586                 /* Decode the update rule */
 587
 588                 switch (obj_desc->common_field.
 589                         field_flags & AML_FIELD_UPDATE_RULE_MASK) {
 590                 case AML_FIELD_UPDATE_PRESERVE:
 591                         /*
 592                          * Check if update rule needs to be applied (not if mask is all
 593                          * ones)  The left shift drops the bits we want to ignore.
 594                          */
 595                         if ((~mask << (ACPI_MUL_8(sizeof(mask)) -
 596                                        ACPI_MUL_8(obj_desc->common_field.
 597                                                   access_byte_width))) != 0) {
 598                                 /*
 599                                  * Read the current contents of the byte/word/dword containing
 600                                  * the field, and merge with the new field value.
 601                                  */
 602                                 status =
 603                                     acpi_ex_field_datum_io(obj_desc,
 604                                                            field_datum_byte_offset,
 605                                                            &current_value,
 606                                                            ACPI_READ);
 607                                 if (ACPI_FAILURE(status)) {
 608                                         return_ACPI_STATUS(status);
 609                                 }
 610
 611                                 merged_value |= (current_value & ~mask);
 612                         }
 613                         break;
 614
 615                 case AML_FIELD_UPDATE_WRITE_AS_ONES:
 616
 617                         /* Set positions outside the field to all ones */
 618
 619                         merged_value |= ~mask;
 620                         break;
 621
 622                 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
 623
 624                         /* Set positions outside the field to all zeros */
 625
 626                         merged_value &= mask;
 627                         break;
 628
 629                 default:
 630
 631                         ACPI_ERROR((AE_INFO,
 632                                     "Unknown UpdateRule value: 0x%X",
 633                                     (obj_desc->common_field.
 634                                      field_flags &
 635                                      AML_FIELD_UPDATE_RULE_MASK)));
 636                         return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
 637                 }
 638         }
 639
 640         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 641                           "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
 642                           ACPI_FORMAT_UINT64(mask),
 643                           field_datum_byte_offset,
 644                           obj_desc->common_field.access_byte_width,
 645                           ACPI_FORMAT_UINT64(field_value),
 646                           ACPI_FORMAT_UINT64(merged_value)));
 647
 648         /* Write the merged value */
 649
 650         status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset,
 651                                         &merged_value, ACPI_WRITE);
 652
 653         return_ACPI_STATUS(status);
 654 }
 655
 656 /*******************************************************************************
 657  *
 658  * FUNCTION:    acpi_ex_extract_from_field
 659  *
 660  * PARAMETERS:  obj_desc            - Field to be read
 661  *              Buffer              - Where to store the field data
 662  *              buffer_length       - Length of Buffer
 663  *
 664  * RETURN:      Status
 665  *
 666  * DESCRIPTION: Retrieve the current value of the given field
 667  *
 668  ******************************************************************************/
 669
 670 acpi_status
 671 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
 672                            void *buffer, u32 buffer_length)
 673 {
 674         acpi_status status;
 675         u64 raw_datum;
 676         u64 merged_datum;
 677         u32 field_offset = 0;
 678         u32 buffer_offset = 0;
 679         u32 buffer_tail_bits;
 680         u32 datum_count;
 681         u32 field_datum_count;
 682         u32 access_bit_width;
 683         u32 i;
 684
 685         ACPI_FUNCTION_TRACE(ex_extract_from_field);
 686
 687         /* Validate target buffer and clear it */
 688
 689         if (buffer_length <
 690             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
 691                 ACPI_ERROR((AE_INFO,
 692                             "Field size %u (bits) is too large for buffer (%u)",
 693                             obj_desc->common_field.bit_length, buffer_length));
 694
 695                 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
 696         }
 697
 698         ACPI_MEMSET(buffer, 0, buffer_length);
 699         access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
 700
 701         /* Handle the simple case here */
 702
 703         if ((obj_desc->common_field.start_field_bit_offset == 0) &&
 704             (obj_desc->common_field.bit_length == access_bit_width)) {
 705                 status = acpi_ex_field_datum_io(obj_desc, 0, buffer, ACPI_READ);
 706                 return_ACPI_STATUS(status);
 707         }
 708
 709 /* TBD: Move to common setup code */
 710
 711         /* Field algorithm is limited to sizeof(u64), truncate if needed */
 712
 713         if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
 714                 obj_desc->common_field.access_byte_width = sizeof(u64);
 715                 access_bit_width = sizeof(u64) * 8;
 716         }
 717
 718         /* Compute the number of datums (access width data items) */
 719
 720         datum_count =
 721             ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
 722                              access_bit_width);
 723
 724         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
 725                                              obj_desc->common_field.
 726                                              start_field_bit_offset,
 727                                              access_bit_width);
 728
 729         /* Priming read from the field */
 730
 731         status =
 732             acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
 733                                    ACPI_READ);
 734         if (ACPI_FAILURE(status)) {
 735                 return_ACPI_STATUS(status);
 736         }
 737         merged_datum =
 738             raw_datum >> obj_desc->common_field.start_field_bit_offset;
 739
 740         /* Read the rest of the field */
 741
 742         for (i = 1; i < field_datum_count; i++) {
 743
 744                 /* Get next input datum from the field */
 745
 746                 field_offset += obj_desc->common_field.access_byte_width;
 747                 status = acpi_ex_field_datum_io(obj_desc, field_offset,
 748                                                 &raw_datum, ACPI_READ);
 749                 if (ACPI_FAILURE(status)) {
 750                         return_ACPI_STATUS(status);
 751                 }
 752
 753                 /*
 754                  * Merge with previous datum if necessary.
 755                  *
 756                  * Note: Before the shift, check if the shift value will be larger than
 757                  * the integer size. If so, there is no need to perform the operation.
 758                  * This avoids the differences in behavior between different compilers
 759                  * concerning shift values larger than the target data width.
 760                  */
 761                 if (access_bit_width -
 762                     obj_desc->common_field.start_field_bit_offset <
 763                     ACPI_INTEGER_BIT_SIZE) {
 764                         merged_datum |=
 765                             raw_datum << (access_bit_width -
 766                                           obj_desc->common_field.
 767                                           start_field_bit_offset);
 768                 }
 769
 770                 if (i == datum_count) {
 771                         break;
 772                 }
 773
 774                 /* Write merged datum to target buffer */
 775
 776                 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
 777                             ACPI_MIN(obj_desc->common_field.access_byte_width,
 778                                      buffer_length - buffer_offset));
 779
 780                 buffer_offset += obj_desc->common_field.access_byte_width;
 781                 merged_datum =
 782                     raw_datum >> obj_desc->common_field.start_field_bit_offset;
 783         }
 784
 785         /* Mask off any extra bits in the last datum */
 786
 787         buffer_tail_bits = obj_desc->common_field.bit_length % access_bit_width;
 788         if (buffer_tail_bits) {
 789                 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
 790         }
 791
 792         /* Write the last datum to the buffer */
 793
 794         ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
 795                     ACPI_MIN(obj_desc->common_field.access_byte_width,
 796                              buffer_length - buffer_offset));
 797
 798         return_ACPI_STATUS(AE_OK);
 799 }
 800
 801 /*******************************************************************************
 802  *
 803  * FUNCTION:    acpi_ex_insert_into_field
 804  *
 805  * PARAMETERS:  obj_desc            - Field to be written
 806  *              Buffer              - Data to be written
 807  *              buffer_length       - Length of Buffer
 808  *
 809  * RETURN:      Status
 810  *
 811  * DESCRIPTION: Store the Buffer contents into the given field
 812  *
 813  ******************************************************************************/
 814
 815 acpi_status
 816 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
 817                           void *buffer, u32 buffer_length)
 818 {
 819         void *new_buffer;
 820         acpi_status status;
 821         u64 mask;
 822         u64 width_mask;
 823         u64 merged_datum;
 824         u64 raw_datum = 0;
 825         u32 field_offset = 0;
 826         u32 buffer_offset = 0;
 827         u32 buffer_tail_bits;
 828         u32 datum_count;
 829         u32 field_datum_count;
 830         u32 access_bit_width;
 831         u32 required_length;
 832         u32 i;
 833
 834         ACPI_FUNCTION_TRACE(ex_insert_into_field);
 835
 836         /* Validate input buffer */
 837
 838         new_buffer = NULL;
 839         required_length =
 840             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
 841         /*
 842          * We must have a buffer that is at least as long as the field
 843          * we are writing to.  This is because individual fields are
 844          * indivisible and partial writes are not supported -- as per
 845          * the ACPI specification.
 846          */
 847         if (buffer_length < required_length) {
 848
 849                 /* We need to create a new buffer */
 850
 851                 new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
 852                 if (!new_buffer) {
 853                         return_ACPI_STATUS(AE_NO_MEMORY);
 854                 }
 855
 856                 /*
 857                  * Copy the original data to the new buffer, starting
 858                  * at Byte zero.  All unused (upper) bytes of the
 859                  * buffer will be 0.
 860                  */
 861                 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length);
 862                 buffer = new_buffer;
 863                 buffer_length = required_length;
 864         }
 865
 866 /* TBD: Move to common setup code */
 867
 868         /* Algo is limited to sizeof(u64), so cut the access_byte_width */
 869         if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
 870                 obj_desc->common_field.access_byte_width = sizeof(u64);
 871         }
 872
 873         access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
 874
 875         /*
 876          * Create the bitmasks used for bit insertion.
 877          * Note: This if/else is used to bypass compiler differences with the
 878          * shift operator
 879          */
 880         if (access_bit_width == ACPI_INTEGER_BIT_SIZE) {
 881                 width_mask = ACPI_UINT64_MAX;
 882         } else {
 883                 width_mask = ACPI_MASK_BITS_ABOVE(access_bit_width);
 884         }
 885
 886         mask = width_mask &
 887             ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
 888
 889         /* Compute the number of datums (access width data items) */
 890
 891         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
 892                                        access_bit_width);
 893
 894         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
 895                                              obj_desc->common_field.
 896                                              start_field_bit_offset,
 897                                              access_bit_width);
 898
 899         /* Get initial Datum from the input buffer */
 900
 901         ACPI_MEMCPY(&raw_datum, buffer,
 902                     ACPI_MIN(obj_desc->common_field.access_byte_width,
 903                              buffer_length - buffer_offset));
 904
 905         merged_datum =
 906             raw_datum << obj_desc->common_field.start_field_bit_offset;
 907
 908         /* Write the entire field */
 909
 910         for (i = 1; i < field_datum_count; i++) {
 911
 912                 /* Write merged datum to the target field */
 913
 914                 merged_datum &= mask;
 915                 status = acpi_ex_write_with_update_rule(obj_desc, mask,
 916                                                         merged_datum,
 917                                                         field_offset);
 918                 if (ACPI_FAILURE(status)) {
 919                         goto exit;
 920                 }
 921
 922                 field_offset += obj_desc->common_field.access_byte_width;
 923
 924                 /*
 925                  * Start new output datum by merging with previous input datum
 926                  * if necessary.
 927                  *
 928                  * Note: Before the shift, check if the shift value will be larger than
 929                  * the integer size. If so, there is no need to perform the operation.
 930                  * This avoids the differences in behavior between different compilers
 931                  * concerning shift values larger than the target data width.
 932                  */
 933                 if ((access_bit_width -
 934                      obj_desc->common_field.start_field_bit_offset) <
 935                     ACPI_INTEGER_BIT_SIZE) {
 936                         merged_datum =
 937                             raw_datum >> (access_bit_width -
 938                                           obj_desc->common_field.
 939                                           start_field_bit_offset);
 940                 } else {
 941                         merged_datum = 0;
 942                 }
 943
 944                 mask = width_mask;
 945
 946                 if (i == datum_count) {
 947                         break;
 948                 }
 949
 950                 /* Get the next input datum from the buffer */
 951
 952                 buffer_offset += obj_desc->common_field.access_byte_width;
 953                 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset,
 954                             ACPI_MIN(obj_desc->common_field.access_byte_width,
 955                                      buffer_length - buffer_offset));
 956
 957                 merged_datum |=
 958                     raw_datum << obj_desc->common_field.start_field_bit_offset;
 959         }
 960
 961         /* Mask off any extra bits in the last datum */
 962
 963         buffer_tail_bits = (obj_desc->common_field.bit_length +
 964                             obj_desc->common_field.start_field_bit_offset) %
 965             access_bit_width;
 966         if (buffer_tail_bits) {
 967                 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
 968         }
 969
 970         /* Write the last datum to the field */
 971
 972         merged_datum &= mask;
 973         status = acpi_ex_write_with_update_rule(obj_desc,
 974                                                 mask, merged_datum,
 975                                                 field_offset);
 976
 977       exit:
 978         /* Free temporary buffer if we used one */
 979
 980         if (new_buffer) {
 981                 ACPI_FREE(new_buffer);
 982         }
 983         return_ACPI_STATUS(status);
 984 }