drivers/acpi/acpica/exfldio.c

   1 /******************************************************************************
   2  *
   3  * Module Name: exfldio - Aml Field I/O
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2017, 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         /*
 127          * Exit now for SMBus, GSBus or IPMI address space, it has a non-linear
 128          * address space and the request cannot be directly validated
 129          */
 130         if (space_id == ACPI_ADR_SPACE_SMBUS ||
 131             space_id == ACPI_ADR_SPACE_GSBUS ||
 132             space_id == ACPI_ADR_SPACE_IPMI) {
 133
 134                 /* SMBus or IPMI has a non-linear address space */
 135
 136                 return_ACPI_STATUS(AE_OK);
 137         }
 138 #ifdef ACPI_UNDER_DEVELOPMENT
 139         /*
 140          * If the Field access is any_acc, we can now compute the optimal
 141          * access (because we know know the length of the parent region)
 142          */
 143         if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 144                 if (ACPI_FAILURE(status)) {
 145                         return_ACPI_STATUS(status);
 146                 }
 147         }
 148 #endif
 149
 150         /*
 151          * Validate the request. The entire request from the byte offset for a
 152          * length of one field datum (access width) must fit within the region.
 153          * (Region length is specified in bytes)
 154          */
 155         if (rgn_desc->region.length <
 156             (obj_desc->common_field.base_byte_offset + field_datum_byte_offset +
 157              obj_desc->common_field.access_byte_width)) {
 158                 if (acpi_gbl_enable_interpreter_slack) {
 159                         /*
 160                          * Slack mode only:  We will go ahead and allow access to this
 161                          * field if it is within the region length rounded up to the next
 162                          * access width boundary. acpi_size cast for 64-bit compile.
 163                          */
 164                         if (ACPI_ROUND_UP(rgn_desc->region.length,
 165                                           obj_desc->common_field.
 166                                           access_byte_width) >=
 167                             ((acpi_size)obj_desc->common_field.
 168                              base_byte_offset +
 169                              obj_desc->common_field.access_byte_width +
 170                              field_datum_byte_offset)) {
 171                                 return_ACPI_STATUS(AE_OK);
 172                         }
 173                 }
 174
 175                 if (rgn_desc->region.length <
 176                     obj_desc->common_field.access_byte_width) {
 177                         /*
 178                          * This is the case where the access_type (acc_word, etc.) is wider
 179                          * than the region itself. For example, a region of length one
 180                          * byte, and a field with Dword access specified.
 181                          */
 182                         ACPI_ERROR((AE_INFO,
 183                                     "Field [%4.4s] access width (%u bytes) "
 184                                     "too large for region [%4.4s] (length %u)",
 185                                     acpi_ut_get_node_name(obj_desc->
 186                                                           common_field.node),
 187                                     obj_desc->common_field.access_byte_width,
 188                                     acpi_ut_get_node_name(rgn_desc->region.
 189                                                           node),
 190                                     rgn_desc->region.length));
 191                 }
 192
 193                 /*
 194                  * Offset rounded up to next multiple of field width
 195                  * exceeds region length, indicate an error
 196                  */
 197                 ACPI_ERROR((AE_INFO,
 198                             "Field [%4.4s] Base+Offset+Width %u+%u+%u "
 199                             "is beyond end of region [%4.4s] (length %u)",
 200                             acpi_ut_get_node_name(obj_desc->common_field.node),
 201                             obj_desc->common_field.base_byte_offset,
 202                             field_datum_byte_offset,
 203                             obj_desc->common_field.access_byte_width,
 204                             acpi_ut_get_node_name(rgn_desc->region.node),
 205                             rgn_desc->region.length));
 206
 207                 return_ACPI_STATUS(AE_AML_REGION_LIMIT);
 208         }
 209
 210         return_ACPI_STATUS(AE_OK);
 211 }
 212
 213 /*******************************************************************************
 214  *
 215  * FUNCTION:    acpi_ex_access_region
 216  *
 217  * PARAMETERS:  obj_desc                - Field to be read
 218  *              field_datum_byte_offset - Byte offset of this datum within the
 219  *                                        parent field
 220  *              value                   - Where to store value (must at least
 221  *                                        64 bits)
 222  *              function                - Read or Write flag plus other region-
 223  *                                        dependent flags
 224  *
 225  * RETURN:      Status
 226  *
 227  * DESCRIPTION: Read or Write a single field datum to an Operation Region.
 228  *
 229  ******************************************************************************/
 230
 231 acpi_status
 232 acpi_ex_access_region(union acpi_operand_object *obj_desc,
 233                       u32 field_datum_byte_offset, u64 *value, u32 function)
 234 {
 235         acpi_status status;
 236         union acpi_operand_object *rgn_desc;
 237         u32 region_offset;
 238
 239         ACPI_FUNCTION_TRACE(ex_access_region);
 240
 241         /*
 242          * Ensure that the region operands are fully evaluated and verify
 243          * the validity of the request
 244          */
 245         status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset);
 246         if (ACPI_FAILURE(status)) {
 247                 return_ACPI_STATUS(status);
 248         }
 249
 250         /*
 251          * The physical address of this field datum is:
 252          *
 253          * 1) The base of the region, plus
 254          * 2) The base offset of the field, plus
 255          * 3) The current offset into the field
 256          */
 257         rgn_desc = obj_desc->common_field.region_obj;
 258         region_offset =
 259             obj_desc->common_field.base_byte_offset + field_datum_byte_offset;
 260
 261         if ((function & ACPI_IO_MASK) == ACPI_READ) {
 262                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
 263         } else {
 264                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
 265         }
 266
 267         ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
 268                               " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %8.8X%8.8X\n",
 269                               acpi_ut_get_region_name(rgn_desc->region.
 270                                                       space_id),
 271                               rgn_desc->region.space_id,
 272                               obj_desc->common_field.access_byte_width,
 273                               obj_desc->common_field.base_byte_offset,
 274                               field_datum_byte_offset,
 275                               ACPI_FORMAT_UINT64(rgn_desc->region.address +
 276                                                  region_offset)));
 277
 278         /* Invoke the appropriate address_space/op_region handler */
 279
 280         status = acpi_ev_address_space_dispatch(rgn_desc, obj_desc,
 281                                                 function, region_offset,
 282                                                 ACPI_MUL_8(obj_desc->
 283                                                            common_field.
 284                                                            access_byte_width),
 285                                                 value);
 286
 287         if (ACPI_FAILURE(status)) {
 288                 if (status == AE_NOT_IMPLEMENTED) {
 289                         ACPI_ERROR((AE_INFO,
 290                                     "Region %s (ID=%u) not implemented",
 291                                     acpi_ut_get_region_name(rgn_desc->region.
 292                                                             space_id),
 293                                     rgn_desc->region.space_id));
 294                 } else if (status == AE_NOT_EXIST) {
 295                         ACPI_ERROR((AE_INFO,
 296                                     "Region %s (ID=%u) has no handler",
 297                                     acpi_ut_get_region_name(rgn_desc->region.
 298                                                             space_id),
 299                                     rgn_desc->region.space_id));
 300                 }
 301         }
 302
 303         return_ACPI_STATUS(status);
 304 }
 305
 306 /*******************************************************************************
 307  *
 308  * FUNCTION:    acpi_ex_register_overflow
 309  *
 310  * PARAMETERS:  obj_desc                - Register(Field) to be written
 311  *              value                   - Value to be stored
 312  *
 313  * RETURN:      TRUE if value overflows the field, FALSE otherwise
 314  *
 315  * DESCRIPTION: Check if a value is out of range of the field being written.
 316  *              Used to check if the values written to Index and Bank registers
 317  *              are out of range. Normally, the value is simply truncated
 318  *              to fit the field, but this case is most likely a serious
 319  *              coding error in the ASL.
 320  *
 321  ******************************************************************************/
 322
 323 static u8
 324 acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 value)
 325 {
 326
 327         if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
 328                 /*
 329                  * The field is large enough to hold the maximum integer, so we can
 330                  * never overflow it.
 331                  */
 332                 return (FALSE);
 333         }
 334
 335         if (value >= ((u64) 1 << obj_desc->common_field.bit_length)) {
 336                 /*
 337                  * The Value is larger than the maximum value that can fit into
 338                  * the register.
 339                  */
 340                 ACPI_ERROR((AE_INFO,
 341                             "Index value 0x%8.8X%8.8X overflows field width 0x%X",
 342                             ACPI_FORMAT_UINT64(value),
 343                             obj_desc->common_field.bit_length));
 344
 345                 return (TRUE);
 346         }
 347
 348         /* The Value will fit into the field with no truncation */
 349
 350         return (FALSE);
 351 }
 352
 353 /*******************************************************************************
 354  *
 355  * FUNCTION:    acpi_ex_field_datum_io
 356  *
 357  * PARAMETERS:  obj_desc                - Field to be read
 358  *              field_datum_byte_offset - Byte offset of this datum within the
 359  *                                        parent field
 360  *              value                   - Where to store value (must be 64 bits)
 361  *              read_write              - Read or Write flag
 362  *
 363  * RETURN:      Status
 364  *
 365  * DESCRIPTION: Read or Write a single datum of a field. The field_type is
 366  *              demultiplexed here to handle the different types of fields
 367  *              (buffer_field, region_field, index_field, bank_field)
 368  *
 369  ******************************************************************************/
 370
 371 static acpi_status
 372 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
 373                        u32 field_datum_byte_offset, u64 *value, u32 read_write)
 374 {
 375         acpi_status status;
 376         u64 local_value;
 377
 378         ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
 379
 380         if (read_write == ACPI_READ) {
 381                 if (!value) {
 382                         local_value = 0;
 383
 384                         /* To support reads without saving return value */
 385                         value = &local_value;
 386                 }
 387
 388                 /* Clear the entire return buffer first, [Very Important!] */
 389
 390                 *value = 0;
 391         }
 392
 393         /*
 394          * The four types of fields are:
 395          *
 396          * buffer_field - Read/write from/to a Buffer
 397          * region_field - Read/write from/to a Operation Region.
 398          * bank_field  - Write to a Bank Register, then read/write from/to an
 399          *               operation_region
 400          * index_field - Write to an Index Register, then read/write from/to a
 401          *               Data Register
 402          */
 403         switch (obj_desc->common.type) {
 404         case ACPI_TYPE_BUFFER_FIELD:
 405                 /*
 406                  * If the buffer_field arguments have not been previously evaluated,
 407                  * evaluate them now and save the results.
 408                  */
 409                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 410                         status = acpi_ds_get_buffer_field_arguments(obj_desc);
 411                         if (ACPI_FAILURE(status)) {
 412                                 return_ACPI_STATUS(status);
 413                         }
 414                 }
 415
 416                 if (read_write == ACPI_READ) {
 417                         /*
 418                          * Copy the data from the source buffer.
 419                          * Length is the field width in bytes.
 420                          */
 421                         memcpy(value,
 422                                (obj_desc->buffer_field.buffer_obj)->buffer.
 423                                pointer +
 424                                obj_desc->buffer_field.base_byte_offset +
 425                                field_datum_byte_offset,
 426                                obj_desc->common_field.access_byte_width);
 427                 } else {
 428                         /*
 429                          * Copy the data to the target buffer.
 430                          * Length is the field width in bytes.
 431                          */
 432                         memcpy((obj_desc->buffer_field.buffer_obj)->buffer.
 433                                pointer +
 434                                obj_desc->buffer_field.base_byte_offset +
 435                                field_datum_byte_offset, value,
 436                                obj_desc->common_field.access_byte_width);
 437                 }
 438
 439                 status = AE_OK;
 440                 break;
 441
 442         case ACPI_TYPE_LOCAL_BANK_FIELD:
 443                 /*
 444                  * Ensure that the bank_value is not beyond the capacity of
 445                  * the register
 446                  */
 447                 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
 448                                               (u64) obj_desc->bank_field.
 449                                               value)) {
 450                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
 451                 }
 452
 453                 /*
 454                  * For bank_fields, we must write the bank_value to the bank_register
 455                  * (itself a region_field) before we can access the data.
 456                  */
 457                 status =
 458                     acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
 459                                               &obj_desc->bank_field.value,
 460                                               sizeof(obj_desc->bank_field.
 461                                                      value));
 462                 if (ACPI_FAILURE(status)) {
 463                         return_ACPI_STATUS(status);
 464                 }
 465
 466                 /*
 467                  * Now that the Bank has been selected, fall through to the
 468                  * region_field case and write the datum to the Operation Region
 469                  */
 470
 471                 /*lint -fallthrough */
 472
 473         case ACPI_TYPE_LOCAL_REGION_FIELD:
 474                 /*
 475                  * For simple region_fields, we just directly access the owning
 476                  * Operation Region.
 477                  */
 478                 status =
 479                     acpi_ex_access_region(obj_desc, field_datum_byte_offset,
 480                                           value, read_write);
 481                 break;
 482
 483         case ACPI_TYPE_LOCAL_INDEX_FIELD:
 484                 /*
 485                  * Ensure that the index_value is not beyond the capacity of
 486                  * the register
 487                  */
 488                 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
 489                                               (u64) obj_desc->index_field.
 490                                               value)) {
 491                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
 492                 }
 493
 494                 /* Write the index value to the index_register (itself a region_field) */
 495
 496                 field_datum_byte_offset += obj_desc->index_field.value;
 497
 498                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 499                                   "Write to Index Register: Value %8.8X\n",
 500                                   field_datum_byte_offset));
 501
 502                 status =
 503                     acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
 504                                               &field_datum_byte_offset,
 505                                               sizeof(field_datum_byte_offset));
 506                 if (ACPI_FAILURE(status)) {
 507                         return_ACPI_STATUS(status);
 508                 }
 509
 510                 if (read_write == ACPI_READ) {
 511
 512                         /* Read the datum from the data_register */
 513
 514                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 515                                           "Read from Data Register\n"));
 516
 517                         status =
 518                             acpi_ex_extract_from_field(obj_desc->index_field.
 519                                                        data_obj, value,
 520                                                        sizeof(u64));
 521                 } else {
 522                         /* Write the datum to the data_register */
 523
 524                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 525                                           "Write to Data Register: Value %8.8X%8.8X\n",
 526                                           ACPI_FORMAT_UINT64(*value)));
 527
 528                         status =
 529                             acpi_ex_insert_into_field(obj_desc->index_field.
 530                                                       data_obj, value,
 531                                                       sizeof(u64));
 532                 }
 533                 break;
 534
 535         default:
 536
 537                 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %u",
 538                             obj_desc->common.type));
 539                 status = AE_AML_INTERNAL;
 540                 break;
 541         }
 542
 543         if (ACPI_SUCCESS(status)) {
 544                 if (read_write == ACPI_READ) {
 545                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 546                                           "Value Read %8.8X%8.8X, Width %u\n",
 547                                           ACPI_FORMAT_UINT64(*value),
 548                                           obj_desc->common_field.
 549                                           access_byte_width));
 550                 } else {
 551                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 552                                           "Value Written %8.8X%8.8X, Width %u\n",
 553                                           ACPI_FORMAT_UINT64(*value),
 554                                           obj_desc->common_field.
 555                                           access_byte_width));
 556                 }
 557         }
 558
 559         return_ACPI_STATUS(status);
 560 }
 561
 562 /*******************************************************************************
 563  *
 564  * FUNCTION:    acpi_ex_write_with_update_rule
 565  *
 566  * PARAMETERS:  obj_desc                - Field to be written
 567  *              mask                    - bitmask within field datum
 568  *              field_value             - Value to write
 569  *              field_datum_byte_offset - Offset of datum within field
 570  *
 571  * RETURN:      Status
 572  *
 573  * DESCRIPTION: Apply the field update rule to a field write
 574  *
 575  ******************************************************************************/
 576
 577 acpi_status
 578 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc,
 579                                u64 mask,
 580                                u64 field_value, u32 field_datum_byte_offset)
 581 {
 582         acpi_status status = AE_OK;
 583         u64 merged_value;
 584         u64 current_value;
 585
 586         ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask);
 587
 588         /* Start with the new bits  */
 589
 590         merged_value = field_value;
 591
 592         /* If the mask is all ones, we don't need to worry about the update rule */
 593
 594         if (mask != ACPI_UINT64_MAX) {
 595
 596                 /* Decode the update rule */
 597
 598                 switch (obj_desc->common_field.
 599                         field_flags & AML_FIELD_UPDATE_RULE_MASK) {
 600                 case AML_FIELD_UPDATE_PRESERVE:
 601                         /*
 602                          * Check if update rule needs to be applied (not if mask is all
 603                          * ones)  The left shift drops the bits we want to ignore.
 604                          */
 605                         if ((~mask << (ACPI_MUL_8(sizeof(mask)) -
 606                                        ACPI_MUL_8(obj_desc->common_field.
 607                                                   access_byte_width))) != 0) {
 608                                 /*
 609                                  * Read the current contents of the byte/word/dword containing
 610                                  * the field, and merge with the new field value.
 611                                  */
 612                                 status =
 613                                     acpi_ex_field_datum_io(obj_desc,
 614                                                            field_datum_byte_offset,
 615                                                            &current_value,
 616                                                            ACPI_READ);
 617                                 if (ACPI_FAILURE(status)) {
 618                                         return_ACPI_STATUS(status);
 619                                 }
 620
 621                                 merged_value |= (current_value & ~mask);
 622                         }
 623                         break;
 624
 625                 case AML_FIELD_UPDATE_WRITE_AS_ONES:
 626
 627                         /* Set positions outside the field to all ones */
 628
 629                         merged_value |= ~mask;
 630                         break;
 631
 632                 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
 633
 634                         /* Set positions outside the field to all zeros */
 635
 636                         merged_value &= mask;
 637                         break;
 638
 639                 default:
 640
 641                         ACPI_ERROR((AE_INFO,
 642                                     "Unknown UpdateRule value: 0x%X",
 643                                     (obj_desc->common_field.field_flags &
 644                                      AML_FIELD_UPDATE_RULE_MASK)));
 645                         return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
 646                 }
 647         }
 648
 649         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 650                           "Mask %8.8X%8.8X, DatumOffset %X, Width %X, "
 651                           "Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
 652                           ACPI_FORMAT_UINT64(mask),
 653                           field_datum_byte_offset,
 654                           obj_desc->common_field.access_byte_width,
 655                           ACPI_FORMAT_UINT64(field_value),
 656                           ACPI_FORMAT_UINT64(merged_value)));
 657
 658         /* Write the merged value */
 659
 660         status =
 661             acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset,
 662                                    &merged_value, ACPI_WRITE);
 663
 664         return_ACPI_STATUS(status);
 665 }
 666
 667 /*******************************************************************************
 668  *
 669  * FUNCTION:    acpi_ex_extract_from_field
 670  *
 671  * PARAMETERS:  obj_desc            - Field to be read
 672  *              buffer              - Where to store the field data
 673  *              buffer_length       - Length of Buffer
 674  *
 675  * RETURN:      Status
 676  *
 677  * DESCRIPTION: Retrieve the current value of the given field
 678  *
 679  ******************************************************************************/
 680
 681 acpi_status
 682 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
 683                            void *buffer, u32 buffer_length)
 684 {
 685         acpi_status status;
 686         u64 raw_datum;
 687         u64 merged_datum;
 688         u32 field_offset = 0;
 689         u32 buffer_offset = 0;
 690         u32 buffer_tail_bits;
 691         u32 datum_count;
 692         u32 field_datum_count;
 693         u32 access_bit_width;
 694         u32 i;
 695
 696         ACPI_FUNCTION_TRACE(ex_extract_from_field);
 697
 698         /* Validate target buffer and clear it */
 699
 700         if (buffer_length <
 701             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
 702                 ACPI_ERROR((AE_INFO,
 703                             "Field size %u (bits) is too large for buffer (%u)",
 704                             obj_desc->common_field.bit_length, buffer_length));
 705
 706                 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
 707         }
 708
 709         memset(buffer, 0, buffer_length);
 710         access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
 711
 712         /* Handle the simple case here */
 713
 714         if ((obj_desc->common_field.start_field_bit_offset == 0) &&
 715             (obj_desc->common_field.bit_length == access_bit_width)) {
 716                 if (buffer_length >= sizeof(u64)) {
 717                         status =
 718                             acpi_ex_field_datum_io(obj_desc, 0, buffer,
 719                                                    ACPI_READ);
 720                 } else {
 721                         /* Use raw_datum (u64) to handle buffers < 64 bits */
 722
 723                         status =
 724                             acpi_ex_field_datum_io(obj_desc, 0, &raw_datum,
 725                                                    ACPI_READ);
 726                         memcpy(buffer, &raw_datum, buffer_length);
 727                 }
 728
 729                 return_ACPI_STATUS(status);
 730         }
 731
 732 /* TBD: Move to common setup code */
 733
 734         /* Field algorithm is limited to sizeof(u64), truncate if needed */
 735
 736         if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
 737                 obj_desc->common_field.access_byte_width = sizeof(u64);
 738                 access_bit_width = sizeof(u64) * 8;
 739         }
 740
 741         /* Compute the number of datums (access width data items) */
 742
 743         datum_count =
 744             ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
 745                              access_bit_width);
 746
 747         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
 748                                              obj_desc->common_field.
 749                                              start_field_bit_offset,
 750                                              access_bit_width);
 751
 752         /* Priming read from the field */
 753
 754         status =
 755             acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
 756                                    ACPI_READ);
 757         if (ACPI_FAILURE(status)) {
 758                 return_ACPI_STATUS(status);
 759         }
 760         merged_datum =
 761             raw_datum >> obj_desc->common_field.start_field_bit_offset;
 762
 763         /* Read the rest of the field */
 764
 765         for (i = 1; i < field_datum_count; i++) {
 766
 767                 /* Get next input datum from the field */
 768
 769                 field_offset += obj_desc->common_field.access_byte_width;
 770                 status =
 771                     acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
 772                                            ACPI_READ);
 773                 if (ACPI_FAILURE(status)) {
 774                         return_ACPI_STATUS(status);
 775                 }
 776
 777                 /*
 778                  * Merge with previous datum if necessary.
 779                  *
 780                  * Note: Before the shift, check if the shift value will be larger than
 781                  * the integer size. If so, there is no need to perform the operation.
 782                  * This avoids the differences in behavior between different compilers
 783                  * concerning shift values larger than the target data width.
 784                  */
 785                 if (access_bit_width -
 786                     obj_desc->common_field.start_field_bit_offset <
 787                     ACPI_INTEGER_BIT_SIZE) {
 788                         merged_datum |=
 789                             raw_datum << (access_bit_width -
 790                                           obj_desc->common_field.
 791                                           start_field_bit_offset);
 792                 }
 793
 794                 if (i == datum_count) {
 795                         break;
 796                 }
 797
 798                 /* Write merged datum to target buffer */
 799
 800                 memcpy(((char *)buffer) + buffer_offset, &merged_datum,
 801                        ACPI_MIN(obj_desc->common_field.access_byte_width,
 802                                 buffer_length - buffer_offset));
 803
 804                 buffer_offset += obj_desc->common_field.access_byte_width;
 805                 merged_datum =
 806                     raw_datum >> obj_desc->common_field.start_field_bit_offset;
 807         }
 808
 809         /* Mask off any extra bits in the last datum */
 810
 811         buffer_tail_bits = obj_desc->common_field.bit_length % access_bit_width;
 812         if (buffer_tail_bits) {
 813                 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
 814         }
 815
 816         /* Write the last datum to the buffer */
 817
 818         memcpy(((char *)buffer) + buffer_offset, &merged_datum,
 819                ACPI_MIN(obj_desc->common_field.access_byte_width,
 820                         buffer_length - buffer_offset));
 821
 822         return_ACPI_STATUS(AE_OK);
 823 }
 824
 825 /*******************************************************************************
 826  *
 827  * FUNCTION:    acpi_ex_insert_into_field
 828  *
 829  * PARAMETERS:  obj_desc            - Field to be written
 830  *              buffer              - Data to be written
 831  *              buffer_length       - Length of Buffer
 832  *
 833  * RETURN:      Status
 834  *
 835  * DESCRIPTION: Store the Buffer contents into the given field
 836  *
 837  ******************************************************************************/
 838
 839 acpi_status
 840 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
 841                           void *buffer, u32 buffer_length)
 842 {
 843         void *new_buffer;
 844         acpi_status status;
 845         u64 mask;
 846         u64 width_mask;
 847         u64 merged_datum;
 848         u64 raw_datum = 0;
 849         u32 field_offset = 0;
 850         u32 buffer_offset = 0;
 851         u32 buffer_tail_bits;
 852         u32 datum_count;
 853         u32 field_datum_count;
 854         u32 access_bit_width;
 855         u32 required_length;
 856         u32 i;
 857
 858         ACPI_FUNCTION_TRACE(ex_insert_into_field);
 859
 860         /* Validate input buffer */
 861
 862         new_buffer = NULL;
 863         required_length =
 864             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
 865
 866         /*
 867          * We must have a buffer that is at least as long as the field
 868          * we are writing to. This is because individual fields are
 869          * indivisible and partial writes are not supported -- as per
 870          * the ACPI specification.
 871          */
 872         if (buffer_length < required_length) {
 873
 874                 /* We need to create a new buffer */
 875
 876                 new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
 877                 if (!new_buffer) {
 878                         return_ACPI_STATUS(AE_NO_MEMORY);
 879                 }
 880
 881                 /*
 882                  * Copy the original data to the new buffer, starting
 883                  * at Byte zero. All unused (upper) bytes of the
 884                  * buffer will be 0.
 885                  */
 886                 memcpy((char *)new_buffer, (char *)buffer, buffer_length);
 887                 buffer = new_buffer;
 888                 buffer_length = required_length;
 889         }
 890
 891 /* TBD: Move to common setup code */
 892
 893         /* Algo is limited to sizeof(u64), so cut the access_byte_width */
 894         if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
 895                 obj_desc->common_field.access_byte_width = sizeof(u64);
 896         }
 897
 898         access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
 899
 900         /* Create the bitmasks used for bit insertion */
 901
 902         width_mask = ACPI_MASK_BITS_ABOVE_64(access_bit_width);
 903         mask = width_mask &
 904             ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
 905
 906         /* Compute the number of datums (access width data items) */
 907
 908         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
 909                                        access_bit_width);
 910
 911         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
 912                                              obj_desc->common_field.
 913                                              start_field_bit_offset,
 914                                              access_bit_width);
 915
 916         /* Get initial Datum from the input buffer */
 917
 918         memcpy(&raw_datum, buffer,
 919                ACPI_MIN(obj_desc->common_field.access_byte_width,
 920                         buffer_length - buffer_offset));
 921
 922         merged_datum =
 923             raw_datum << obj_desc->common_field.start_field_bit_offset;
 924
 925         /* Write the entire field */
 926
 927         for (i = 1; i < field_datum_count; i++) {
 928
 929                 /* Write merged datum to the target field */
 930
 931                 merged_datum &= mask;
 932                 status =
 933                     acpi_ex_write_with_update_rule(obj_desc, mask, merged_datum,
 934                                                    field_offset);
 935                 if (ACPI_FAILURE(status)) {
 936                         goto exit;
 937                 }
 938
 939                 field_offset += obj_desc->common_field.access_byte_width;
 940
 941                 /*
 942                  * Start new output datum by merging with previous input datum
 943                  * if necessary.
 944                  *
 945                  * Note: Before the shift, check if the shift value will be larger than
 946                  * the integer size. If so, there is no need to perform the operation.
 947                  * This avoids the differences in behavior between different compilers
 948                  * concerning shift values larger than the target data width.
 949                  */
 950                 if ((access_bit_width -
 951                      obj_desc->common_field.start_field_bit_offset) <
 952                     ACPI_INTEGER_BIT_SIZE) {
 953                         merged_datum =
 954                             raw_datum >> (access_bit_width -
 955                                           obj_desc->common_field.
 956                                           start_field_bit_offset);
 957                 } else {
 958                         merged_datum = 0;
 959                 }
 960
 961                 mask = width_mask;
 962
 963                 if (i == datum_count) {
 964                         break;
 965                 }
 966
 967                 /* Get the next input datum from the buffer */
 968
 969                 buffer_offset += obj_desc->common_field.access_byte_width;
 970                 memcpy(&raw_datum, ((char *)buffer) + buffer_offset,
 971                        ACPI_MIN(obj_desc->common_field.access_byte_width,
 972                                 buffer_length - buffer_offset));
 973
 974                 merged_datum |=
 975                     raw_datum << obj_desc->common_field.start_field_bit_offset;
 976         }
 977
 978         /* Mask off any extra bits in the last datum */
 979
 980         buffer_tail_bits = (obj_desc->common_field.bit_length +
 981                             obj_desc->common_field.start_field_bit_offset) %
 982             access_bit_width;
 983         if (buffer_tail_bits) {
 984                 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
 985         }
 986
 987         /* Write the last datum to the field */
 988
 989         merged_datum &= mask;
 990         status =
 991             acpi_ex_write_with_update_rule(obj_desc, mask, merged_datum,
 992                                            field_offset);
 993
 994 exit:
 995         /* Free temporary buffer if we used one */
 996
 997         if (new_buffer) {
 998                 ACPI_FREE(new_buffer);
 999         }
1000         return_ACPI_STATUS(status);
1001 }