drivers/acpi/acpica/exfldio.c

   1 /******************************************************************************
   2  *
   3  * Module Name: exfldio - Aml Field I/O
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2013, 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, u64 *value, u32 read_write);
  58
  59 static u8
  60 acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 value);
  61
  62 static acpi_status
  63 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
  64                      u32 field_datum_byte_offset);
  65
  66 /*******************************************************************************
  67  *
  68  * FUNCTION:    acpi_ex_setup_region
  69  *
  70  * PARAMETERS:  obj_desc                - Field to be read or written
  71  *              field_datum_byte_offset - Byte offset of this datum within the
  72  *                                        parent field
  73  *
  74  * RETURN:      Status
  75  *
  76  * DESCRIPTION: Common processing for acpi_ex_extract_from_field and
  77  *              acpi_ex_insert_into_field. Initialize the Region if necessary and
  78  *              validate the request.
  79  *
  80  ******************************************************************************/
  81
  82 static acpi_status
  83 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
  84                      u32 field_datum_byte_offset)
  85 {
  86         acpi_status status = AE_OK;
  87         union acpi_operand_object *rgn_desc;
  88         u8 space_id;
  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         space_id = rgn_desc->region.space_id;
 105
 106         /* Validate the Space ID */
 107
 108         if (!acpi_is_valid_space_id(space_id)) {
 109                 ACPI_ERROR((AE_INFO,
 110                             "Invalid/unknown Address Space ID: 0x%2.2X",
 111                             space_id));
 112                 return_ACPI_STATUS(AE_AML_INVALID_SPACE_ID);
 113         }
 114
 115         /*
 116          * If the Region Address and Length have not been previously evaluated,
 117          * evaluate them now and save the results.
 118          */
 119         if (!(rgn_desc->common.flags & AOPOBJ_DATA_VALID)) {
 120                 status = acpi_ds_get_region_arguments(rgn_desc);
 121                 if (ACPI_FAILURE(status)) {
 122                         return_ACPI_STATUS(status);
 123                 }
 124         }
 125
 126         /* Exit if Address/Length have been disallowed by the host OS */
 127
 128         if (rgn_desc->common.flags & AOPOBJ_INVALID) {
 129                 return_ACPI_STATUS(AE_AML_ILLEGAL_ADDRESS);
 130         }
 131
 132         /*
 133          * Exit now for SMBus, GSBus or IPMI address space, it has a non-linear
 134          * address space and the request cannot be directly validated
 135          */
 136         if (space_id == ACPI_ADR_SPACE_SMBUS ||
 137             space_id == ACPI_ADR_SPACE_GSBUS ||
 138             space_id == ACPI_ADR_SPACE_IPMI) {
 139
 140                 /* SMBus or IPMI has a non-linear address space */
 141
 142                 return_ACPI_STATUS(AE_OK);
 143         }
 144 #ifdef ACPI_UNDER_DEVELOPMENT
 145         /*
 146          * If the Field access is any_acc, we can now compute the optimal
 147          * access (because we know know the length of the parent region)
 148          */
 149         if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 150                 if (ACPI_FAILURE(status)) {
 151                         return_ACPI_STATUS(status);
 152                 }
 153         }
 154 #endif
 155
 156         /*
 157          * Validate the request. The entire request from the byte offset for a
 158          * length of one field datum (access width) must fit within the region.
 159          * (Region length is specified in bytes)
 160          */
 161         if (rgn_desc->region.length <
 162             (obj_desc->common_field.base_byte_offset + field_datum_byte_offset +
 163              obj_desc->common_field.access_byte_width)) {
 164                 if (acpi_gbl_enable_interpreter_slack) {
 165                         /*
 166                          * Slack mode only:  We will go ahead and allow access to this
 167                          * field if it is within the region length rounded up to the next
 168                          * access width boundary. acpi_size cast for 64-bit compile.
 169                          */
 170                         if (ACPI_ROUND_UP(rgn_desc->region.length,
 171                                           obj_desc->common_field.
 172                                           access_byte_width) >=
 173                             ((acpi_size) obj_desc->common_field.
 174                              base_byte_offset +
 175                              obj_desc->common_field.access_byte_width +
 176                              field_datum_byte_offset)) {
 177                                 return_ACPI_STATUS(AE_OK);
 178                         }
 179                 }
 180
 181                 if (rgn_desc->region.length <
 182                     obj_desc->common_field.access_byte_width) {
 183                         /*
 184                          * This is the case where the access_type (acc_word, etc.) is wider
 185                          * than the region itself. For example, a region of length one
 186                          * byte, and a field with Dword access specified.
 187                          */
 188                         ACPI_ERROR((AE_INFO,
 189                                     "Field [%4.4s] access width (%u bytes) too large for region [%4.4s] (length %u)",
 190                                     acpi_ut_get_node_name(obj_desc->
 191                                                           common_field.node),
 192                                     obj_desc->common_field.access_byte_width,
 193                                     acpi_ut_get_node_name(rgn_desc->region.
 194                                                           node),
 195                                     rgn_desc->region.length));
 196                 }
 197
 198                 /*
 199                  * Offset rounded up to next multiple of field width
 200                  * exceeds region length, indicate an error
 201                  */
 202                 ACPI_ERROR((AE_INFO,
 203                             "Field [%4.4s] Base+Offset+Width %u+%u+%u is beyond end of region [%4.4s] (length %u)",
 204                             acpi_ut_get_node_name(obj_desc->common_field.node),
 205                             obj_desc->common_field.base_byte_offset,
 206                             field_datum_byte_offset,
 207                             obj_desc->common_field.access_byte_width,
 208                             acpi_ut_get_node_name(rgn_desc->region.node),
 209                             rgn_desc->region.length));
 210
 211                 return_ACPI_STATUS(AE_AML_REGION_LIMIT);
 212         }
 213
 214         return_ACPI_STATUS(AE_OK);
 215 }
 216
 217 /*******************************************************************************
 218  *
 219  * FUNCTION:    acpi_ex_access_region
 220  *
 221  * PARAMETERS:  obj_desc                - Field to be read
 222  *              field_datum_byte_offset - Byte offset of this datum within the
 223  *                                        parent field
 224  *              value                   - Where to store value (must at least
 225  *                                        64 bits)
 226  *              function                - Read or Write flag plus other region-
 227  *                                        dependent flags
 228  *
 229  * RETURN:      Status
 230  *
 231  * DESCRIPTION: Read or Write a single field datum to an Operation Region.
 232  *
 233  ******************************************************************************/
 234
 235 acpi_status
 236 acpi_ex_access_region(union acpi_operand_object *obj_desc,
 237                       u32 field_datum_byte_offset, u64 *value, u32 function)
 238 {
 239         acpi_status status;
 240         union acpi_operand_object *rgn_desc;
 241         u32 region_offset;
 242
 243         ACPI_FUNCTION_TRACE(ex_access_region);
 244
 245         /*
 246          * Ensure that the region operands are fully evaluated and verify
 247          * the validity of the request
 248          */
 249         status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset);
 250         if (ACPI_FAILURE(status)) {
 251                 return_ACPI_STATUS(status);
 252         }
 253
 254         /*
 255          * The physical address of this field datum is:
 256          *
 257          * 1) The base of the region, plus
 258          * 2) The base offset of the field, plus
 259          * 3) The current offset into the field
 260          */
 261         rgn_desc = obj_desc->common_field.region_obj;
 262         region_offset =
 263             obj_desc->common_field.base_byte_offset + field_datum_byte_offset;
 264
 265         if ((function & ACPI_IO_MASK) == ACPI_READ) {
 266                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
 267         } else {
 268                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
 269         }
 270
 271         ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
 272                               " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n",
 273                               acpi_ut_get_region_name(rgn_desc->region.
 274                                                       space_id),
 275                               rgn_desc->region.space_id,
 276                               obj_desc->common_field.access_byte_width,
 277                               obj_desc->common_field.base_byte_offset,
 278                               field_datum_byte_offset, ACPI_CAST_PTR(void,
 279                                                                      (rgn_desc->
 280                                                                       region.
 281                                                                       address +
 282                                                                       region_offset))));
 283
 284         /* Invoke the appropriate address_space/op_region handler */
 285
 286         status = acpi_ev_address_space_dispatch(rgn_desc, obj_desc,
 287                                                 function, region_offset,
 288                                                 ACPI_MUL_8(obj_desc->
 289                                                            common_field.
 290                                                            access_byte_width),
 291                                                 value);
 292
 293         if (ACPI_FAILURE(status)) {
 294                 if (status == AE_NOT_IMPLEMENTED) {
 295                         ACPI_ERROR((AE_INFO,
 296                                     "Region %s (ID=%u) not implemented",
 297                                     acpi_ut_get_region_name(rgn_desc->region.
 298                                                             space_id),
 299                                     rgn_desc->region.space_id));
 300                 } else if (status == AE_NOT_EXIST) {
 301                         ACPI_ERROR((AE_INFO,
 302                                     "Region %s (ID=%u) has no handler",
 303                                     acpi_ut_get_region_name(rgn_desc->region.
 304                                                             space_id),
 305                                     rgn_desc->region.space_id));
 306                 }
 307         }
 308
 309         return_ACPI_STATUS(status);
 310 }
 311
 312 /*******************************************************************************
 313  *
 314  * FUNCTION:    acpi_ex_register_overflow
 315  *
 316  * PARAMETERS:  obj_desc                - Register(Field) to be written
 317  *              value                   - Value to be stored
 318  *
 319  * RETURN:      TRUE if value overflows the field, FALSE otherwise
 320  *
 321  * DESCRIPTION: Check if a value is out of range of the field being written.
 322  *              Used to check if the values written to Index and Bank registers
 323  *              are out of range. Normally, the value is simply truncated
 324  *              to fit the field, but this case is most likely a serious
 325  *              coding error in the ASL.
 326  *
 327  ******************************************************************************/
 328
 329 static u8
 330 acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 value)
 331 {
 332
 333         if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
 334                 /*
 335                  * The field is large enough to hold the maximum integer, so we can
 336                  * never overflow it.
 337                  */
 338                 return (FALSE);
 339         }
 340
 341         if (value >= ((u64) 1 << obj_desc->common_field.bit_length)) {
 342                 /*
 343                  * The Value is larger than the maximum value that can fit into
 344                  * the register.
 345                  */
 346                 ACPI_ERROR((AE_INFO,
 347                             "Index value 0x%8.8X%8.8X overflows field width 0x%X",
 348                             ACPI_FORMAT_UINT64(value),
 349                             obj_desc->common_field.bit_length));
 350
 351                 return (TRUE);
 352         }
 353
 354         /* The Value will fit into the field with no truncation */
 355
 356         return (FALSE);
 357 }
 358
 359 /*******************************************************************************
 360  *
 361  * FUNCTION:    acpi_ex_field_datum_io
 362  *
 363  * PARAMETERS:  obj_desc                - Field to be read
 364  *              field_datum_byte_offset - Byte offset of this datum within the
 365  *                                        parent field
 366  *              value                   - Where to store value (must be 64 bits)
 367  *              read_write              - Read or Write flag
 368  *
 369  * RETURN:      Status
 370  *
 371  * DESCRIPTION: Read or Write a single datum of a field. The field_type is
 372  *              demultiplexed here to handle the different types of fields
 373  *              (buffer_field, region_field, index_field, bank_field)
 374  *
 375  ******************************************************************************/
 376
 377 static acpi_status
 378 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
 379                        u32 field_datum_byte_offset, u64 *value, u32 read_write)
 380 {
 381         acpi_status status;
 382         u64 local_value;
 383
 384         ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
 385
 386         if (read_write == ACPI_READ) {
 387                 if (!value) {
 388                         local_value = 0;
 389
 390                         /* To support reads without saving return value */
 391                         value = &local_value;
 392                 }
 393
 394                 /* Clear the entire return buffer first, [Very Important!] */
 395
 396                 *value = 0;
 397         }
 398
 399         /*
 400          * The four types of fields are:
 401          *
 402          * buffer_field - Read/write from/to a Buffer
 403          * region_field - Read/write from/to a Operation Region.
 404          * bank_field  - Write to a Bank Register, then read/write from/to an
 405          *               operation_region
 406          * index_field - Write to an Index Register, then read/write from/to a
 407          *               Data Register
 408          */
 409         switch (obj_desc->common.type) {
 410         case ACPI_TYPE_BUFFER_FIELD:
 411                 /*
 412                  * If the buffer_field arguments have not been previously evaluated,
 413                  * evaluate them now and save the results.
 414                  */
 415                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 416                         status = acpi_ds_get_buffer_field_arguments(obj_desc);
 417                         if (ACPI_FAILURE(status)) {
 418                                 return_ACPI_STATUS(status);
 419                         }
 420                 }
 421
 422                 if (read_write == ACPI_READ) {
 423                         /*
 424                          * Copy the data from the source buffer.
 425                          * Length is the field width in bytes.
 426                          */
 427                         ACPI_MEMCPY(value,
 428                                     (obj_desc->buffer_field.buffer_obj)->buffer.
 429                                     pointer +
 430                                     obj_desc->buffer_field.base_byte_offset +
 431                                     field_datum_byte_offset,
 432                                     obj_desc->common_field.access_byte_width);
 433                 } else {
 434                         /*
 435                          * Copy the data to the target buffer.
 436                          * Length is the field width in bytes.
 437                          */
 438                         ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer.
 439                                     pointer +
 440                                     obj_desc->buffer_field.base_byte_offset +
 441                                     field_datum_byte_offset, value,
 442                                     obj_desc->common_field.access_byte_width);
 443                 }
 444
 445                 status = AE_OK;
 446                 break;
 447
 448         case ACPI_TYPE_LOCAL_BANK_FIELD:
 449                 /*
 450                  * Ensure that the bank_value is not beyond the capacity of
 451                  * the register
 452                  */
 453                 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
 454                                               (u64) obj_desc->bank_field.
 455                                               value)) {
 456                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
 457                 }
 458
 459                 /*
 460                  * For bank_fields, we must write the bank_value to the bank_register
 461                  * (itself a region_field) before we can access the data.
 462                  */
 463                 status =
 464                     acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
 465                                               &obj_desc->bank_field.value,
 466                                               sizeof(obj_desc->bank_field.
 467                                                      value));
 468                 if (ACPI_FAILURE(status)) {
 469                         return_ACPI_STATUS(status);
 470                 }
 471
 472                 /*
 473                  * Now that the Bank has been selected, fall through to the
 474                  * region_field case and write the datum to the Operation Region
 475                  */
 476
 477                 /*lint -fallthrough */
 478
 479         case ACPI_TYPE_LOCAL_REGION_FIELD:
 480                 /*
 481                  * For simple region_fields, we just directly access the owning
 482                  * Operation Region.
 483                  */
 484                 status =
 485                     acpi_ex_access_region(obj_desc, field_datum_byte_offset,
 486                                           value, read_write);
 487                 break;
 488
 489         case ACPI_TYPE_LOCAL_INDEX_FIELD:
 490                 /*
 491                  * Ensure that the index_value is not beyond the capacity of
 492                  * the register
 493                  */
 494                 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
 495                                               (u64) obj_desc->index_field.
 496                                               value)) {
 497                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
 498                 }
 499
 500                 /* Write the index value to the index_register (itself a region_field) */
 501
 502                 field_datum_byte_offset += obj_desc->index_field.value;
 503
 504                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 505                                   "Write to Index Register: Value %8.8X\n",
 506                                   field_datum_byte_offset));
 507
 508                 status =
 509                     acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
 510                                               &field_datum_byte_offset,
 511                                               sizeof(field_datum_byte_offset));
 512                 if (ACPI_FAILURE(status)) {
 513                         return_ACPI_STATUS(status);
 514                 }
 515
 516                 if (read_write == ACPI_READ) {
 517
 518                         /* Read the datum from the data_register */
 519
 520                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 521                                           "Read from Data Register\n"));
 522
 523                         status =
 524                             acpi_ex_extract_from_field(obj_desc->index_field.
 525                                                        data_obj, value,
 526                                                        sizeof(u64));
 527                 } else {
 528                         /* Write the datum to the data_register */
 529
 530                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 531                                           "Write to Data Register: Value %8.8X%8.8X\n",
 532                                           ACPI_FORMAT_UINT64(*value)));
 533
 534                         status =
 535                             acpi_ex_insert_into_field(obj_desc->index_field.
 536                                                       data_obj, value,
 537                                                       sizeof(u64));
 538                 }
 539                 break;
 540
 541         default:
 542
 543                 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %u",
 544                             obj_desc->common.type));
 545                 status = AE_AML_INTERNAL;
 546                 break;
 547         }
 548
 549         if (ACPI_SUCCESS(status)) {
 550                 if (read_write == ACPI_READ) {
 551                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 552                                           "Value Read %8.8X%8.8X, Width %u\n",
 553                                           ACPI_FORMAT_UINT64(*value),
 554                                           obj_desc->common_field.
 555                                           access_byte_width));
 556                 } else {
 557                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 558                                           "Value Written %8.8X%8.8X, Width %u\n",
 559                                           ACPI_FORMAT_UINT64(*value),
 560                                           obj_desc->common_field.
 561                                           access_byte_width));
 562                 }
 563         }
 564
 565         return_ACPI_STATUS(status);
 566 }
 567
 568 /*******************************************************************************
 569  *
 570  * FUNCTION:    acpi_ex_write_with_update_rule
 571  *
 572  * PARAMETERS:  obj_desc                - Field to be written
 573  *              mask                    - bitmask within field datum
 574  *              field_value             - Value to write
 575  *              field_datum_byte_offset - Offset of datum within field
 576  *
 577  * RETURN:      Status
 578  *
 579  * DESCRIPTION: Apply the field update rule to a field write
 580  *
 581  ******************************************************************************/
 582
 583 acpi_status
 584 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc,
 585                                u64 mask,
 586                                u64 field_value, u32 field_datum_byte_offset)
 587 {
 588         acpi_status status = AE_OK;
 589         u64 merged_value;
 590         u64 current_value;
 591
 592         ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask);
 593
 594         /* Start with the new bits  */
 595
 596         merged_value = field_value;
 597
 598         /* If the mask is all ones, we don't need to worry about the update rule */
 599
 600         if (mask != ACPI_UINT64_MAX) {
 601
 602                 /* Decode the update rule */
 603
 604                 switch (obj_desc->common_field.
 605                         field_flags & AML_FIELD_UPDATE_RULE_MASK) {
 606                 case AML_FIELD_UPDATE_PRESERVE:
 607                         /*
 608                          * Check if update rule needs to be applied (not if mask is all
 609                          * ones)  The left shift drops the bits we want to ignore.
 610                          */
 611                         if ((~mask << (ACPI_MUL_8(sizeof(mask)) -
 612                                        ACPI_MUL_8(obj_desc->common_field.
 613                                                   access_byte_width))) != 0) {
 614                                 /*
 615                                  * Read the current contents of the byte/word/dword containing
 616                                  * the field, and merge with the new field value.
 617                                  */
 618                                 status =
 619                                     acpi_ex_field_datum_io(obj_desc,
 620                                                            field_datum_byte_offset,
 621                                                            &current_value,
 622                                                            ACPI_READ);
 623                                 if (ACPI_FAILURE(status)) {
 624                                         return_ACPI_STATUS(status);
 625                                 }
 626
 627                                 merged_value |= (current_value & ~mask);
 628                         }
 629                         break;
 630
 631                 case AML_FIELD_UPDATE_WRITE_AS_ONES:
 632
 633                         /* Set positions outside the field to all ones */
 634
 635                         merged_value |= ~mask;
 636                         break;
 637
 638                 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
 639
 640                         /* Set positions outside the field to all zeros */
 641
 642                         merged_value &= mask;
 643                         break;
 644
 645                 default:
 646
 647                         ACPI_ERROR((AE_INFO,
 648                                     "Unknown UpdateRule value: 0x%X",
 649                                     (obj_desc->common_field.
 650                                      field_flags &
 651                                      AML_FIELD_UPDATE_RULE_MASK)));
 652                         return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
 653                 }
 654         }
 655
 656         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 657                           "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
 658                           ACPI_FORMAT_UINT64(mask),
 659                           field_datum_byte_offset,
 660                           obj_desc->common_field.access_byte_width,
 661                           ACPI_FORMAT_UINT64(field_value),
 662                           ACPI_FORMAT_UINT64(merged_value)));
 663
 664         /* Write the merged value */
 665
 666         status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset,
 667                                         &merged_value, ACPI_WRITE);
 668
 669         return_ACPI_STATUS(status);
 670 }
 671
 672 /*******************************************************************************
 673  *
 674  * FUNCTION:    acpi_ex_extract_from_field
 675  *
 676  * PARAMETERS:  obj_desc            - Field to be read
 677  *              buffer              - Where to store the field data
 678  *              buffer_length       - Length of Buffer
 679  *
 680  * RETURN:      Status
 681  *
 682  * DESCRIPTION: Retrieve the current value of the given field
 683  *
 684  ******************************************************************************/
 685
 686 acpi_status
 687 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
 688                            void *buffer, u32 buffer_length)
 689 {
 690         acpi_status status;
 691         u64 raw_datum;
 692         u64 merged_datum;
 693         u32 field_offset = 0;
 694         u32 buffer_offset = 0;
 695         u32 buffer_tail_bits;
 696         u32 datum_count;
 697         u32 field_datum_count;
 698         u32 access_bit_width;
 699         u32 i;
 700
 701         ACPI_FUNCTION_TRACE(ex_extract_from_field);
 702
 703         /* Validate target buffer and clear it */
 704
 705         if (buffer_length <
 706             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
 707                 ACPI_ERROR((AE_INFO,
 708                             "Field size %u (bits) is too large for buffer (%u)",
 709                             obj_desc->common_field.bit_length, buffer_length));
 710
 711                 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
 712         }
 713
 714         ACPI_MEMSET(buffer, 0, buffer_length);
 715         access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
 716
 717         /* Handle the simple case here */
 718
 719         if ((obj_desc->common_field.start_field_bit_offset == 0) &&
 720             (obj_desc->common_field.bit_length == access_bit_width)) {
 721                 if (buffer_length >= sizeof(u64)) {
 722                         status =
 723                             acpi_ex_field_datum_io(obj_desc, 0, buffer,
 724                                                    ACPI_READ);
 725                 } else {
 726                         /* Use raw_datum (u64) to handle buffers < 64 bits */
 727
 728                         status =
 729                             acpi_ex_field_datum_io(obj_desc, 0, &raw_datum,
 730                                                    ACPI_READ);
 731                         ACPI_MEMCPY(buffer, &raw_datum, buffer_length);
 732                 }
 733
 734                 return_ACPI_STATUS(status);
 735         }
 736
 737 /* TBD: Move to common setup code */
 738
 739         /* Field algorithm is limited to sizeof(u64), truncate if needed */
 740
 741         if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
 742                 obj_desc->common_field.access_byte_width = sizeof(u64);
 743                 access_bit_width = sizeof(u64) * 8;
 744         }
 745
 746         /* Compute the number of datums (access width data items) */
 747
 748         datum_count =
 749             ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
 750                              access_bit_width);
 751
 752         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
 753                                              obj_desc->common_field.
 754                                              start_field_bit_offset,
 755                                              access_bit_width);
 756
 757         /* Priming read from the field */
 758
 759         status =
 760             acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
 761                                    ACPI_READ);
 762         if (ACPI_FAILURE(status)) {
 763                 return_ACPI_STATUS(status);
 764         }
 765         merged_datum =
 766             raw_datum >> obj_desc->common_field.start_field_bit_offset;
 767
 768         /* Read the rest of the field */
 769
 770         for (i = 1; i < field_datum_count; i++) {
 771
 772                 /* Get next input datum from the field */
 773
 774                 field_offset += obj_desc->common_field.access_byte_width;
 775                 status = acpi_ex_field_datum_io(obj_desc, field_offset,
 776                                                 &raw_datum, ACPI_READ);
 777                 if (ACPI_FAILURE(status)) {
 778                         return_ACPI_STATUS(status);
 779                 }
 780
 781                 /*
 782                  * Merge with previous datum if necessary.
 783                  *
 784                  * Note: Before the shift, check if the shift value will be larger than
 785                  * the integer size. If so, there is no need to perform the operation.
 786                  * This avoids the differences in behavior between different compilers
 787                  * concerning shift values larger than the target data width.
 788                  */
 789                 if (access_bit_width -
 790                     obj_desc->common_field.start_field_bit_offset <
 791                     ACPI_INTEGER_BIT_SIZE) {
 792                         merged_datum |=
 793                             raw_datum << (access_bit_width -
 794                                           obj_desc->common_field.
 795                                           start_field_bit_offset);
 796                 }
 797
 798                 if (i == datum_count) {
 799                         break;
 800                 }
 801
 802                 /* Write merged datum to target buffer */
 803
 804                 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
 805                             ACPI_MIN(obj_desc->common_field.access_byte_width,
 806                                      buffer_length - buffer_offset));
 807
 808                 buffer_offset += obj_desc->common_field.access_byte_width;
 809                 merged_datum =
 810                     raw_datum >> obj_desc->common_field.start_field_bit_offset;
 811         }
 812
 813         /* Mask off any extra bits in the last datum */
 814
 815         buffer_tail_bits = obj_desc->common_field.bit_length % access_bit_width;
 816         if (buffer_tail_bits) {
 817                 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
 818         }
 819
 820         /* Write the last datum to the buffer */
 821
 822         ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
 823                     ACPI_MIN(obj_desc->common_field.access_byte_width,
 824                              buffer_length - buffer_offset));
 825
 826         return_ACPI_STATUS(AE_OK);
 827 }
 828
 829 /*******************************************************************************
 830  *
 831  * FUNCTION:    acpi_ex_insert_into_field
 832  *
 833  * PARAMETERS:  obj_desc            - Field to be written
 834  *              buffer              - Data to be written
 835  *              buffer_length       - Length of Buffer
 836  *
 837  * RETURN:      Status
 838  *
 839  * DESCRIPTION: Store the Buffer contents into the given field
 840  *
 841  ******************************************************************************/
 842
 843 acpi_status
 844 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
 845                           void *buffer, u32 buffer_length)
 846 {
 847         void *new_buffer;
 848         acpi_status status;
 849         u64 mask;
 850         u64 width_mask;
 851         u64 merged_datum;
 852         u64 raw_datum = 0;
 853         u32 field_offset = 0;
 854         u32 buffer_offset = 0;
 855         u32 buffer_tail_bits;
 856         u32 datum_count;
 857         u32 field_datum_count;
 858         u32 access_bit_width;
 859         u32 required_length;
 860         u32 i;
 861
 862         ACPI_FUNCTION_TRACE(ex_insert_into_field);
 863
 864         /* Validate input buffer */
 865
 866         new_buffer = NULL;
 867         required_length =
 868             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
 869         /*
 870          * We must have a buffer that is at least as long as the field
 871          * we are writing to. This is because individual fields are
 872          * indivisible and partial writes are not supported -- as per
 873          * the ACPI specification.
 874          */
 875         if (buffer_length < required_length) {
 876
 877                 /* We need to create a new buffer */
 878
 879                 new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
 880                 if (!new_buffer) {
 881                         return_ACPI_STATUS(AE_NO_MEMORY);
 882                 }
 883
 884                 /*
 885                  * Copy the original data to the new buffer, starting
 886                  * at Byte zero. All unused (upper) bytes of the
 887                  * buffer will be 0.
 888                  */
 889                 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length);
 890                 buffer = new_buffer;
 891                 buffer_length = required_length;
 892         }
 893
 894 /* TBD: Move to common setup code */
 895
 896         /* Algo is limited to sizeof(u64), so cut the access_byte_width */
 897         if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
 898                 obj_desc->common_field.access_byte_width = sizeof(u64);
 899         }
 900
 901         access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
 902
 903         /*
 904          * Create the bitmasks used for bit insertion.
 905          * Note: This if/else is used to bypass compiler differences with the
 906          * shift operator
 907          */
 908         if (access_bit_width == ACPI_INTEGER_BIT_SIZE) {
 909                 width_mask = ACPI_UINT64_MAX;
 910         } else {
 911                 width_mask = ACPI_MASK_BITS_ABOVE(access_bit_width);
 912         }
 913
 914         mask = width_mask &
 915             ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
 916
 917         /* Compute the number of datums (access width data items) */
 918
 919         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
 920                                        access_bit_width);
 921
 922         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
 923                                              obj_desc->common_field.
 924                                              start_field_bit_offset,
 925                                              access_bit_width);
 926
 927         /* Get initial Datum from the input buffer */
 928
 929         ACPI_MEMCPY(&raw_datum, buffer,
 930                     ACPI_MIN(obj_desc->common_field.access_byte_width,
 931                              buffer_length - buffer_offset));
 932
 933         merged_datum =
 934             raw_datum << obj_desc->common_field.start_field_bit_offset;
 935
 936         /* Write the entire field */
 937
 938         for (i = 1; i < field_datum_count; i++) {
 939
 940                 /* Write merged datum to the target field */
 941
 942                 merged_datum &= mask;
 943                 status = acpi_ex_write_with_update_rule(obj_desc, mask,
 944                                                         merged_datum,
 945                                                         field_offset);
 946                 if (ACPI_FAILURE(status)) {
 947                         goto exit;
 948                 }
 949
 950                 field_offset += obj_desc->common_field.access_byte_width;
 951
 952                 /*
 953                  * Start new output datum by merging with previous input datum
 954                  * if necessary.
 955                  *
 956                  * Note: Before the shift, check if the shift value will be larger than
 957                  * the integer size. If so, there is no need to perform the operation.
 958                  * This avoids the differences in behavior between different compilers
 959                  * concerning shift values larger than the target data width.
 960                  */
 961                 if ((access_bit_width -
 962                      obj_desc->common_field.start_field_bit_offset) <
 963                     ACPI_INTEGER_BIT_SIZE) {
 964                         merged_datum =
 965                             raw_datum >> (access_bit_width -
 966                                           obj_desc->common_field.
 967                                           start_field_bit_offset);
 968                 } else {
 969                         merged_datum = 0;
 970                 }
 971
 972                 mask = width_mask;
 973
 974                 if (i == datum_count) {
 975                         break;
 976                 }
 977
 978                 /* Get the next input datum from the buffer */
 979
 980                 buffer_offset += obj_desc->common_field.access_byte_width;
 981                 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset,
 982                             ACPI_MIN(obj_desc->common_field.access_byte_width,
 983                                      buffer_length - buffer_offset));
 984
 985                 merged_datum |=
 986                     raw_datum << obj_desc->common_field.start_field_bit_offset;
 987         }
 988
 989         /* Mask off any extra bits in the last datum */
 990
 991         buffer_tail_bits = (obj_desc->common_field.bit_length +
 992                             obj_desc->common_field.start_field_bit_offset) %
 993             access_bit_width;
 994         if (buffer_tail_bits) {
 995                 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
 996         }
 997
 998         /* Write the last datum to the field */
 999
1000         merged_datum &= mask;
1001         status = acpi_ex_write_with_update_rule(obj_desc,
1002                                                 mask, merged_datum,
1003                                                 field_offset);
1004
1005       exit:
1006         /* Free temporary buffer if we used one */
1007
1008         if (new_buffer) {
1009                 ACPI_FREE(new_buffer);
1010         }
1011         return_ACPI_STATUS(status);
1012 }