drivers/acpi/acpica/exfldio.c

   1 /******************************************************************************
   2  *
   3  * Module Name: exfldio - Aml Field I/O
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2012, 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         u8 space_id;
  90
  91         ACPI_FUNCTION_TRACE_U32(ex_setup_region, field_datum_byte_offset);
  92
  93         rgn_desc = obj_desc->common_field.region_obj;
  94
  95         /* We must have a valid region */
  96
  97         if (rgn_desc->common.type != ACPI_TYPE_REGION) {
  98                 ACPI_ERROR((AE_INFO, "Needed Region, found type 0x%X (%s)",
  99                             rgn_desc->common.type,
 100                             acpi_ut_get_object_type_name(rgn_desc)));
 101
 102                 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
 103         }
 104
 105         space_id = rgn_desc->region.space_id;
 106
 107         /* Validate the Space ID */
 108
 109         if (!acpi_is_valid_space_id(space_id)) {
 110                 ACPI_ERROR((AE_INFO,
 111                             "Invalid/unknown Address Space ID: 0x%2.2X",
 112                             space_id));
 113                 return_ACPI_STATUS(AE_AML_INVALID_SPACE_ID);
 114         }
 115
 116         /*
 117          * If the Region Address and Length have not been previously evaluated,
 118          * evaluate them now and save the results.
 119          */
 120         if (!(rgn_desc->common.flags & AOPOBJ_DATA_VALID)) {
 121                 status = acpi_ds_get_region_arguments(rgn_desc);
 122                 if (ACPI_FAILURE(status)) {
 123                         return_ACPI_STATUS(status);
 124                 }
 125         }
 126
 127         /* Exit if Address/Length have been disallowed by the host OS */
 128
 129         if (rgn_desc->common.flags & AOPOBJ_INVALID) {
 130                 return_ACPI_STATUS(AE_AML_ILLEGAL_ADDRESS);
 131         }
 132
 133         /*
 134          * Exit now for SMBus, GSBus or IPMI address space, it has a non-linear
 135          * address space and the request cannot be directly validated
 136          */
 137         if (space_id == ACPI_ADR_SPACE_SMBUS ||
 138             space_id == ACPI_ADR_SPACE_GSBUS ||
 139             space_id == ACPI_ADR_SPACE_IPMI) {
 140
 141                 /* SMBus or IPMI has a non-linear address space */
 142
 143                 return_ACPI_STATUS(AE_OK);
 144         }
 145 #ifdef ACPI_UNDER_DEVELOPMENT
 146         /*
 147          * If the Field access is any_acc, we can now compute the optimal
 148          * access (because we know know the length of the parent region)
 149          */
 150         if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 151                 if (ACPI_FAILURE(status)) {
 152                         return_ACPI_STATUS(status);
 153                 }
 154         }
 155 #endif
 156
 157         /*
 158          * Validate the request.  The entire request from the byte offset for a
 159          * length of one field datum (access width) must fit within the region.
 160          * (Region length is specified in bytes)
 161          */
 162         if (rgn_desc->region.length <
 163             (obj_desc->common_field.base_byte_offset + field_datum_byte_offset +
 164              obj_desc->common_field.access_byte_width)) {
 165                 if (acpi_gbl_enable_interpreter_slack) {
 166                         /*
 167                          * Slack mode only:  We will go ahead and allow access to this
 168                          * field if it is within the region length rounded up to the next
 169                          * access width boundary. acpi_size cast for 64-bit compile.
 170                          */
 171                         if (ACPI_ROUND_UP(rgn_desc->region.length,
 172                                           obj_desc->common_field.
 173                                           access_byte_width) >=
 174                             ((acpi_size) obj_desc->common_field.
 175                              base_byte_offset +
 176                              obj_desc->common_field.access_byte_width +
 177                              field_datum_byte_offset)) {
 178                                 return_ACPI_STATUS(AE_OK);
 179                         }
 180                 }
 181
 182                 if (rgn_desc->region.length <
 183                     obj_desc->common_field.access_byte_width) {
 184                         /*
 185                          * This is the case where the access_type (acc_word, etc.) is wider
 186                          * than the region itself.  For example, a region of length one
 187                          * byte, and a field with Dword access specified.
 188                          */
 189                         ACPI_ERROR((AE_INFO,
 190                                     "Field [%4.4s] access width (%u bytes) too large for region [%4.4s] (length %u)",
 191                                     acpi_ut_get_node_name(obj_desc->
 192                                                           common_field.node),
 193                                     obj_desc->common_field.access_byte_width,
 194                                     acpi_ut_get_node_name(rgn_desc->region.
 195                                                           node),
 196                                     rgn_desc->region.length));
 197                 }
 198
 199                 /*
 200                  * Offset rounded up to next multiple of field width
 201                  * exceeds region length, indicate an error
 202                  */
 203                 ACPI_ERROR((AE_INFO,
 204                             "Field [%4.4s] Base+Offset+Width %u+%u+%u is beyond end of region [%4.4s] (length %u)",
 205                             acpi_ut_get_node_name(obj_desc->common_field.node),
 206                             obj_desc->common_field.base_byte_offset,
 207                             field_datum_byte_offset,
 208                             obj_desc->common_field.access_byte_width,
 209                             acpi_ut_get_node_name(rgn_desc->region.node),
 210                             rgn_desc->region.length));
 211
 212                 return_ACPI_STATUS(AE_AML_REGION_LIMIT);
 213         }
 214
 215         return_ACPI_STATUS(AE_OK);
 216 }
 217
 218 /*******************************************************************************
 219  *
 220  * FUNCTION:    acpi_ex_access_region
 221  *
 222  * PARAMETERS:  obj_desc                - Field to be read
 223  *              field_datum_byte_offset - Byte offset of this datum within the
 224  *                                        parent field
 225  *              Value                   - Where to store value (must at least
 226  *                                        64 bits)
 227  *              Function                - Read or Write flag plus other region-
 228  *                                        dependent flags
 229  *
 230  * RETURN:      Status
 231  *
 232  * DESCRIPTION: Read or Write a single field datum to an Operation Region.
 233  *
 234  ******************************************************************************/
 235
 236 acpi_status
 237 acpi_ex_access_region(union acpi_operand_object *obj_desc,
 238                       u32 field_datum_byte_offset, u64 *value, u32 function)
 239 {
 240         acpi_status status;
 241         union acpi_operand_object *rgn_desc;
 242         u32 region_offset;
 243
 244         ACPI_FUNCTION_TRACE(ex_access_region);
 245
 246         /*
 247          * Ensure that the region operands are fully evaluated and verify
 248          * the validity of the request
 249          */
 250         status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset);
 251         if (ACPI_FAILURE(status)) {
 252                 return_ACPI_STATUS(status);
 253         }
 254
 255         /*
 256          * The physical address of this field datum is:
 257          *
 258          * 1) The base of the region, plus
 259          * 2) The base offset of the field, plus
 260          * 3) The current offset into the field
 261          */
 262         rgn_desc = obj_desc->common_field.region_obj;
 263         region_offset =
 264             obj_desc->common_field.base_byte_offset + field_datum_byte_offset;
 265
 266         if ((function & ACPI_IO_MASK) == ACPI_READ) {
 267                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
 268         } else {
 269                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
 270         }
 271
 272         ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
 273                               " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n",
 274                               acpi_ut_get_region_name(rgn_desc->region.
 275                                                       space_id),
 276                               rgn_desc->region.space_id,
 277                               obj_desc->common_field.access_byte_width,
 278                               obj_desc->common_field.base_byte_offset,
 279                               field_datum_byte_offset, ACPI_CAST_PTR(void,
 280                                                                      (rgn_desc->
 281                                                                       region.
 282                                                                       address +
 283                                                                       region_offset))));
 284
 285         /* Invoke the appropriate address_space/op_region handler */
 286
 287         status = acpi_ev_address_space_dispatch(rgn_desc, obj_desc,
 288                                                 function, region_offset,
 289                                                 ACPI_MUL_8(obj_desc->
 290                                                            common_field.
 291                                                            access_byte_width),
 292                                                 value);
 293
 294         if (ACPI_FAILURE(status)) {
 295                 if (status == AE_NOT_IMPLEMENTED) {
 296                         ACPI_ERROR((AE_INFO,
 297                                     "Region %s (ID=%u) not implemented",
 298                                     acpi_ut_get_region_name(rgn_desc->region.
 299                                                             space_id),
 300                                     rgn_desc->region.space_id));
 301                 } else if (status == AE_NOT_EXIST) {
 302                         ACPI_ERROR((AE_INFO,
 303                                     "Region %s (ID=%u) has no handler",
 304                                     acpi_ut_get_region_name(rgn_desc->region.
 305                                                             space_id),
 306                                     rgn_desc->region.space_id));
 307                 }
 308         }
 309
 310         return_ACPI_STATUS(status);
 311 }
 312
 313 /*******************************************************************************
 314  *
 315  * FUNCTION:    acpi_ex_register_overflow
 316  *
 317  * PARAMETERS:  obj_desc                - Register(Field) to be written
 318  *              Value                   - Value to be stored
 319  *
 320  * RETURN:      TRUE if value overflows the field, FALSE otherwise
 321  *
 322  * DESCRIPTION: Check if a value is out of range of the field being written.
 323  *              Used to check if the values written to Index and Bank registers
 324  *              are out of range.  Normally, the value is simply truncated
 325  *              to fit the field, but this case is most likely a serious
 326  *              coding error in the ASL.
 327  *
 328  ******************************************************************************/
 329
 330 static u8
 331 acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 value)
 332 {
 333         ACPI_FUNCTION_NAME(ex_register_overflow);
 334
 335         if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
 336                 /*
 337                  * The field is large enough to hold the maximum integer, so we can
 338                  * never overflow it.
 339                  */
 340                 return (FALSE);
 341         }
 342
 343         if (value >= ((u64) 1 << obj_desc->common_field.bit_length)) {
 344                 /*
 345                  * The Value is larger than the maximum value that can fit into
 346                  * the register.
 347                  */
 348                 ACPI_ERROR((AE_INFO,
 349                             "Index value 0x%8.8X%8.8X overflows field width 0x%X",
 350                             ACPI_FORMAT_UINT64(value),
 351                             obj_desc->common_field.bit_length));
 352
 353                 return (TRUE);
 354         }
 355
 356         /* The Value will fit into the field with no truncation */
 357
 358         return (FALSE);
 359 }
 360
 361 /*******************************************************************************
 362  *
 363  * FUNCTION:    acpi_ex_field_datum_io
 364  *
 365  * PARAMETERS:  obj_desc                - Field to be read
 366  *              field_datum_byte_offset - Byte offset of this datum within the
 367  *                                        parent field
 368  *              Value                   - Where to store value (must be 64 bits)
 369  *              read_write              - Read or Write flag
 370  *
 371  * RETURN:      Status
 372  *
 373  * DESCRIPTION: Read or Write a single datum of a field.  The field_type is
 374  *              demultiplexed here to handle the different types of fields
 375  *              (buffer_field, region_field, index_field, bank_field)
 376  *
 377  ******************************************************************************/
 378
 379 static acpi_status
 380 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
 381                        u32 field_datum_byte_offset, u64 *value, u32 read_write)
 382 {
 383         acpi_status status;
 384         u64 local_value;
 385
 386         ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
 387
 388         if (read_write == ACPI_READ) {
 389                 if (!value) {
 390                         local_value = 0;
 391
 392                         /* To support reads without saving return value */
 393                         value = &local_value;
 394                 }
 395
 396                 /* Clear the entire return buffer first, [Very Important!] */
 397
 398                 *value = 0;
 399         }
 400
 401         /*
 402          * The four types of fields are:
 403          *
 404          * buffer_field - Read/write from/to a Buffer
 405          * region_field - Read/write from/to a Operation Region.
 406          * bank_field  - Write to a Bank Register, then read/write from/to an
 407          *               operation_region
 408          * index_field - Write to an Index Register, then read/write from/to a
 409          *               Data Register
 410          */
 411         switch (obj_desc->common.type) {
 412         case ACPI_TYPE_BUFFER_FIELD:
 413                 /*
 414                  * If the buffer_field arguments have not been previously evaluated,
 415                  * evaluate them now and save the results.
 416                  */
 417                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 418                         status = acpi_ds_get_buffer_field_arguments(obj_desc);
 419                         if (ACPI_FAILURE(status)) {
 420                                 return_ACPI_STATUS(status);
 421                         }
 422                 }
 423
 424                 if (read_write == ACPI_READ) {
 425                         /*
 426                          * Copy the data from the source buffer.
 427                          * Length is the field width in bytes.
 428                          */
 429                         ACPI_MEMCPY(value,
 430                                     (obj_desc->buffer_field.buffer_obj)->buffer.
 431                                     pointer +
 432                                     obj_desc->buffer_field.base_byte_offset +
 433                                     field_datum_byte_offset,
 434                                     obj_desc->common_field.access_byte_width);
 435                 } else {
 436                         /*
 437                          * Copy the data to the target buffer.
 438                          * Length is the field width in bytes.
 439                          */
 440                         ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer.
 441                                     pointer +
 442                                     obj_desc->buffer_field.base_byte_offset +
 443                                     field_datum_byte_offset, value,
 444                                     obj_desc->common_field.access_byte_width);
 445                 }
 446
 447                 status = AE_OK;
 448                 break;
 449
 450         case ACPI_TYPE_LOCAL_BANK_FIELD:
 451
 452                 /*
 453                  * Ensure that the bank_value is not beyond the capacity of
 454                  * the register
 455                  */
 456                 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
 457                                               (u64) obj_desc->bank_field.
 458                                               value)) {
 459                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
 460                 }
 461
 462                 /*
 463                  * For bank_fields, we must write the bank_value to the bank_register
 464                  * (itself a region_field) before we can access the data.
 465                  */
 466                 status =
 467                     acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
 468                                               &obj_desc->bank_field.value,
 469                                               sizeof(obj_desc->bank_field.
 470                                                      value));
 471                 if (ACPI_FAILURE(status)) {
 472                         return_ACPI_STATUS(status);
 473                 }
 474
 475                 /*
 476                  * Now that the Bank has been selected, fall through to the
 477                  * region_field case and write the datum to the Operation Region
 478                  */
 479
 480                 /*lint -fallthrough */
 481
 482         case ACPI_TYPE_LOCAL_REGION_FIELD:
 483                 /*
 484                  * For simple region_fields, we just directly access the owning
 485                  * Operation Region.
 486                  */
 487                 status =
 488                     acpi_ex_access_region(obj_desc, field_datum_byte_offset,
 489                                           value, read_write);
 490                 break;
 491
 492         case ACPI_TYPE_LOCAL_INDEX_FIELD:
 493
 494                 /*
 495                  * Ensure that the index_value is not beyond the capacity of
 496                  * the register
 497                  */
 498                 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
 499                                               (u64) obj_desc->index_field.
 500                                               value)) {
 501                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
 502                 }
 503
 504                 /* Write the index value to the index_register (itself a region_field) */
 505
 506                 field_datum_byte_offset += obj_desc->index_field.value;
 507
 508                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 509                                   "Write to Index Register: Value %8.8X\n",
 510                                   field_datum_byte_offset));
 511
 512                 status =
 513                     acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
 514                                               &field_datum_byte_offset,
 515                                               sizeof(field_datum_byte_offset));
 516                 if (ACPI_FAILURE(status)) {
 517                         return_ACPI_STATUS(status);
 518                 }
 519
 520                 if (read_write == ACPI_READ) {
 521
 522                         /* Read the datum from the data_register */
 523
 524                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 525                                           "Read from Data Register\n"));
 526
 527                         status =
 528                             acpi_ex_extract_from_field(obj_desc->index_field.
 529                                                        data_obj, value,
 530                                                        sizeof(u64));
 531                 } else {
 532                         /* Write the datum to the data_register */
 533
 534                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 535                                           "Write to Data Register: Value %8.8X%8.8X\n",
 536                                           ACPI_FORMAT_UINT64(*value)));
 537
 538                         status =
 539                             acpi_ex_insert_into_field(obj_desc->index_field.
 540                                                       data_obj, value,
 541                                                       sizeof(u64));
 542                 }
 543                 break;
 544
 545         default:
 546
 547                 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %u",
 548                             obj_desc->common.type));
 549                 status = AE_AML_INTERNAL;
 550                 break;
 551         }
 552
 553         if (ACPI_SUCCESS(status)) {
 554                 if (read_write == ACPI_READ) {
 555                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 556                                           "Value Read %8.8X%8.8X, Width %u\n",
 557                                           ACPI_FORMAT_UINT64(*value),
 558                                           obj_desc->common_field.
 559                                           access_byte_width));
 560                 } else {
 561                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 562                                           "Value Written %8.8X%8.8X, Width %u\n",
 563                                           ACPI_FORMAT_UINT64(*value),
 564                                           obj_desc->common_field.
 565                                           access_byte_width));
 566                 }
 567         }
 568
 569         return_ACPI_STATUS(status);
 570 }
 571
 572 /*******************************************************************************
 573  *
 574  * FUNCTION:    acpi_ex_write_with_update_rule
 575  *
 576  * PARAMETERS:  obj_desc                - Field to be written
 577  *              Mask                    - bitmask within field datum
 578  *              field_value             - Value to write
 579  *              field_datum_byte_offset - Offset of datum within field
 580  *
 581  * RETURN:      Status
 582  *
 583  * DESCRIPTION: Apply the field update rule to a field write
 584  *
 585  ******************************************************************************/
 586
 587 acpi_status
 588 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc,
 589                                u64 mask,
 590                                u64 field_value, u32 field_datum_byte_offset)
 591 {
 592         acpi_status status = AE_OK;
 593         u64 merged_value;
 594         u64 current_value;
 595
 596         ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask);
 597
 598         /* Start with the new bits  */
 599
 600         merged_value = field_value;
 601
 602         /* If the mask is all ones, we don't need to worry about the update rule */
 603
 604         if (mask != ACPI_UINT64_MAX) {
 605
 606                 /* Decode the update rule */
 607
 608                 switch (obj_desc->common_field.
 609                         field_flags & AML_FIELD_UPDATE_RULE_MASK) {
 610                 case AML_FIELD_UPDATE_PRESERVE:
 611                         /*
 612                          * Check if update rule needs to be applied (not if mask is all
 613                          * ones)  The left shift drops the bits we want to ignore.
 614                          */
 615                         if ((~mask << (ACPI_MUL_8(sizeof(mask)) -
 616                                        ACPI_MUL_8(obj_desc->common_field.
 617                                                   access_byte_width))) != 0) {
 618                                 /*
 619                                  * Read the current contents of the byte/word/dword containing
 620                                  * the field, and merge with the new field value.
 621                                  */
 622                                 status =
 623                                     acpi_ex_field_datum_io(obj_desc,
 624                                                            field_datum_byte_offset,
 625                                                            &current_value,
 626                                                            ACPI_READ);
 627                                 if (ACPI_FAILURE(status)) {
 628                                         return_ACPI_STATUS(status);
 629                                 }
 630
 631                                 merged_value |= (current_value & ~mask);
 632                         }
 633                         break;
 634
 635                 case AML_FIELD_UPDATE_WRITE_AS_ONES:
 636
 637                         /* Set positions outside the field to all ones */
 638
 639                         merged_value |= ~mask;
 640                         break;
 641
 642                 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
 643
 644                         /* Set positions outside the field to all zeros */
 645
 646                         merged_value &= mask;
 647                         break;
 648
 649                 default:
 650
 651                         ACPI_ERROR((AE_INFO,
 652                                     "Unknown UpdateRule value: 0x%X",
 653                                     (obj_desc->common_field.
 654                                      field_flags &
 655                                      AML_FIELD_UPDATE_RULE_MASK)));
 656                         return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
 657                 }
 658         }
 659
 660         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 661                           "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
 662                           ACPI_FORMAT_UINT64(mask),
 663                           field_datum_byte_offset,
 664                           obj_desc->common_field.access_byte_width,
 665                           ACPI_FORMAT_UINT64(field_value),
 666                           ACPI_FORMAT_UINT64(merged_value)));
 667
 668         /* Write the merged value */
 669
 670         status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset,
 671                                         &merged_value, ACPI_WRITE);
 672
 673         return_ACPI_STATUS(status);
 674 }
 675
 676 /*******************************************************************************
 677  *
 678  * FUNCTION:    acpi_ex_extract_from_field
 679  *
 680  * PARAMETERS:  obj_desc            - Field to be read
 681  *              Buffer              - Where to store the field data
 682  *              buffer_length       - Length of Buffer
 683  *
 684  * RETURN:      Status
 685  *
 686  * DESCRIPTION: Retrieve the current value of the given field
 687  *
 688  ******************************************************************************/
 689
 690 acpi_status
 691 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
 692                            void *buffer, u32 buffer_length)
 693 {
 694         acpi_status status;
 695         u64 raw_datum;
 696         u64 merged_datum;
 697         u32 field_offset = 0;
 698         u32 buffer_offset = 0;
 699         u32 buffer_tail_bits;
 700         u32 datum_count;
 701         u32 field_datum_count;
 702         u32 access_bit_width;
 703         u32 i;
 704
 705         ACPI_FUNCTION_TRACE(ex_extract_from_field);
 706
 707         /* Validate target buffer and clear it */
 708
 709         if (buffer_length <
 710             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
 711                 ACPI_ERROR((AE_INFO,
 712                             "Field size %u (bits) is too large for buffer (%u)",
 713                             obj_desc->common_field.bit_length, buffer_length));
 714
 715                 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
 716         }
 717
 718         ACPI_MEMSET(buffer, 0, buffer_length);
 719         access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
 720
 721         /* Handle the simple case here */
 722
 723         if ((obj_desc->common_field.start_field_bit_offset == 0) &&
 724             (obj_desc->common_field.bit_length == access_bit_width)) {
 725                 status = acpi_ex_field_datum_io(obj_desc, 0, buffer, ACPI_READ);
 726                 return_ACPI_STATUS(status);
 727         }
 728
 729 /* TBD: Move to common setup code */
 730
 731         /* Field algorithm is limited to sizeof(u64), truncate if needed */
 732
 733         if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
 734                 obj_desc->common_field.access_byte_width = sizeof(u64);
 735                 access_bit_width = sizeof(u64) * 8;
 736         }
 737
 738         /* Compute the number of datums (access width data items) */
 739
 740         datum_count =
 741             ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
 742                              access_bit_width);
 743
 744         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
 745                                              obj_desc->common_field.
 746                                              start_field_bit_offset,
 747                                              access_bit_width);
 748
 749         /* Priming read from the field */
 750
 751         status =
 752             acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
 753                                    ACPI_READ);
 754         if (ACPI_FAILURE(status)) {
 755                 return_ACPI_STATUS(status);
 756         }
 757         merged_datum =
 758             raw_datum >> obj_desc->common_field.start_field_bit_offset;
 759
 760         /* Read the rest of the field */
 761
 762         for (i = 1; i < field_datum_count; i++) {
 763
 764                 /* Get next input datum from the field */
 765
 766                 field_offset += obj_desc->common_field.access_byte_width;
 767                 status = acpi_ex_field_datum_io(obj_desc, field_offset,
 768                                                 &raw_datum, ACPI_READ);
 769                 if (ACPI_FAILURE(status)) {
 770                         return_ACPI_STATUS(status);
 771                 }
 772
 773                 /*
 774                  * Merge with previous datum if necessary.
 775                  *
 776                  * Note: Before the shift, check if the shift value will be larger than
 777                  * the integer size. If so, there is no need to perform the operation.
 778                  * This avoids the differences in behavior between different compilers
 779                  * concerning shift values larger than the target data width.
 780                  */
 781                 if (access_bit_width -
 782                     obj_desc->common_field.start_field_bit_offset <
 783                     ACPI_INTEGER_BIT_SIZE) {
 784                         merged_datum |=
 785                             raw_datum << (access_bit_width -
 786                                           obj_desc->common_field.
 787                                           start_field_bit_offset);
 788                 }
 789
 790                 if (i == datum_count) {
 791                         break;
 792                 }
 793
 794                 /* Write merged datum to target buffer */
 795
 796                 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
 797                             ACPI_MIN(obj_desc->common_field.access_byte_width,
 798                                      buffer_length - buffer_offset));
 799
 800                 buffer_offset += obj_desc->common_field.access_byte_width;
 801                 merged_datum =
 802                     raw_datum >> obj_desc->common_field.start_field_bit_offset;
 803         }
 804
 805         /* Mask off any extra bits in the last datum */
 806
 807         buffer_tail_bits = obj_desc->common_field.bit_length % access_bit_width;
 808         if (buffer_tail_bits) {
 809                 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
 810         }
 811
 812         /* Write the last datum to the buffer */
 813
 814         ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
 815                     ACPI_MIN(obj_desc->common_field.access_byte_width,
 816                              buffer_length - buffer_offset));
 817
 818         return_ACPI_STATUS(AE_OK);
 819 }
 820
 821 /*******************************************************************************
 822  *
 823  * FUNCTION:    acpi_ex_insert_into_field
 824  *
 825  * PARAMETERS:  obj_desc            - Field to be written
 826  *              Buffer              - Data to be written
 827  *              buffer_length       - Length of Buffer
 828  *
 829  * RETURN:      Status
 830  *
 831  * DESCRIPTION: Store the Buffer contents into the given field
 832  *
 833  ******************************************************************************/
 834
 835 acpi_status
 836 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
 837                           void *buffer, u32 buffer_length)
 838 {
 839         void *new_buffer;
 840         acpi_status status;
 841         u64 mask;
 842         u64 width_mask;
 843         u64 merged_datum;
 844         u64 raw_datum = 0;
 845         u32 field_offset = 0;
 846         u32 buffer_offset = 0;
 847         u32 buffer_tail_bits;
 848         u32 datum_count;
 849         u32 field_datum_count;
 850         u32 access_bit_width;
 851         u32 required_length;
 852         u32 i;
 853
 854         ACPI_FUNCTION_TRACE(ex_insert_into_field);
 855
 856         /* Validate input buffer */
 857
 858         new_buffer = NULL;
 859         required_length =
 860             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
 861         /*
 862          * We must have a buffer that is at least as long as the field
 863          * we are writing to.  This is because individual fields are
 864          * indivisible and partial writes are not supported -- as per
 865          * the ACPI specification.
 866          */
 867         if (buffer_length < required_length) {
 868
 869                 /* We need to create a new buffer */
 870
 871                 new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
 872                 if (!new_buffer) {
 873                         return_ACPI_STATUS(AE_NO_MEMORY);
 874                 }
 875
 876                 /*
 877                  * Copy the original data to the new buffer, starting
 878                  * at Byte zero.  All unused (upper) bytes of the
 879                  * buffer will be 0.
 880                  */
 881                 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length);
 882                 buffer = new_buffer;
 883                 buffer_length = required_length;
 884         }
 885
 886 /* TBD: Move to common setup code */
 887
 888         /* Algo is limited to sizeof(u64), so cut the access_byte_width */
 889         if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
 890                 obj_desc->common_field.access_byte_width = sizeof(u64);
 891         }
 892
 893         access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
 894
 895         /*
 896          * Create the bitmasks used for bit insertion.
 897          * Note: This if/else is used to bypass compiler differences with the
 898          * shift operator
 899          */
 900         if (access_bit_width == ACPI_INTEGER_BIT_SIZE) {
 901                 width_mask = ACPI_UINT64_MAX;
 902         } else {
 903                 width_mask = ACPI_MASK_BITS_ABOVE(access_bit_width);
 904         }
 905
 906         mask = width_mask &
 907             ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
 908
 909         /* Compute the number of datums (access width data items) */
 910
 911         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
 912                                        access_bit_width);
 913
 914         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
 915                                              obj_desc->common_field.
 916                                              start_field_bit_offset,
 917                                              access_bit_width);
 918
 919         /* Get initial Datum from the input buffer */
 920
 921         ACPI_MEMCPY(&raw_datum, buffer,
 922                     ACPI_MIN(obj_desc->common_field.access_byte_width,
 923                              buffer_length - buffer_offset));
 924
 925         merged_datum =
 926             raw_datum << obj_desc->common_field.start_field_bit_offset;
 927
 928         /* Write the entire field */
 929
 930         for (i = 1; i < field_datum_count; i++) {
 931
 932                 /* Write merged datum to the target field */
 933
 934                 merged_datum &= mask;
 935                 status = acpi_ex_write_with_update_rule(obj_desc, mask,
 936                                                         merged_datum,
 937                                                         field_offset);
 938                 if (ACPI_FAILURE(status)) {
 939                         goto exit;
 940                 }
 941
 942                 field_offset += obj_desc->common_field.access_byte_width;
 943
 944                 /*
 945                  * Start new output datum by merging with previous input datum
 946                  * if necessary.
 947                  *
 948                  * Note: Before the shift, check if the shift value will be larger than
 949                  * the integer size. If so, there is no need to perform the operation.
 950                  * This avoids the differences in behavior between different compilers
 951                  * concerning shift values larger than the target data width.
 952                  */
 953                 if ((access_bit_width -
 954                      obj_desc->common_field.start_field_bit_offset) <
 955                     ACPI_INTEGER_BIT_SIZE) {
 956                         merged_datum =
 957                             raw_datum >> (access_bit_width -
 958                                           obj_desc->common_field.
 959                                           start_field_bit_offset);
 960                 } else {
 961                         merged_datum = 0;
 962                 }
 963
 964                 mask = width_mask;
 965
 966                 if (i == datum_count) {
 967                         break;
 968                 }
 969
 970                 /* Get the next input datum from the buffer */
 971
 972                 buffer_offset += obj_desc->common_field.access_byte_width;
 973                 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset,
 974                             ACPI_MIN(obj_desc->common_field.access_byte_width,
 975                                      buffer_length - buffer_offset));
 976
 977                 merged_datum |=
 978                     raw_datum << obj_desc->common_field.start_field_bit_offset;
 979         }
 980
 981         /* Mask off any extra bits in the last datum */
 982
 983         buffer_tail_bits = (obj_desc->common_field.bit_length +
 984                             obj_desc->common_field.start_field_bit_offset) %
 985             access_bit_width;
 986         if (buffer_tail_bits) {
 987                 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
 988         }
 989
 990         /* Write the last datum to the field */
 991
 992         merged_datum &= mask;
 993         status = acpi_ex_write_with_update_rule(obj_desc,
 994                                                 mask, merged_datum,
 995                                                 field_offset);
 996
 997       exit:
 998         /* Free temporary buffer if we used one */
 999
1000         if (new_buffer) {
1001                 ACPI_FREE(new_buffer);
1002         }
1003         return_ACPI_STATUS(status);
1004 }