drivers/acpi/acpica/exfldio.c

   1 /******************************************************************************
   2  *
   3  * Module Name: exfldio - Aml Field I/O
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2008, 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                        acpi_integer * value, u32 read_write);
  59
  60 static u8
  61 acpi_ex_register_overflow(union acpi_operand_object *obj_desc,
  62                           acpi_integer value);
  63
  64 static acpi_status
  65 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
  66                      u32 field_datum_byte_offset);
  67
  68 /*******************************************************************************
  69  *
  70  * FUNCTION:    acpi_ex_setup_region
  71  *
  72  * PARAMETERS:  obj_desc                - Field to be read or written
  73  *              field_datum_byte_offset - Byte offset of this datum within the
  74  *                                        parent field
  75  *
  76  * RETURN:      Status
  77  *
  78  * DESCRIPTION: Common processing for acpi_ex_extract_from_field and
  79  *              acpi_ex_insert_into_field. Initialize the Region if necessary and
  80  *              validate the request.
  81  *
  82  ******************************************************************************/
  83
  84 static acpi_status
  85 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
  86                      u32 field_datum_byte_offset)
  87 {
  88         acpi_status status = AE_OK;
  89         union acpi_operand_object *rgn_desc;
  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 %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         /*
 106          * If the Region Address and Length have not been previously evaluated,
 107          * evaluate them now and save the results.
 108          */
 109         if (!(rgn_desc->common.flags & AOPOBJ_DATA_VALID)) {
 110                 status = acpi_ds_get_region_arguments(rgn_desc);
 111                 if (ACPI_FAILURE(status)) {
 112                         return_ACPI_STATUS(status);
 113                 }
 114         }
 115
 116         /* Exit if Address/Length have been disallowed by the host OS */
 117
 118         if (rgn_desc->common.flags & AOPOBJ_INVALID) {
 119                 return_ACPI_STATUS(AE_AML_ILLEGAL_ADDRESS);
 120         }
 121
 122         /*
 123          * Exit now for SMBus address space, it has a non-linear address space
 124          * and the request cannot be directly validated
 125          */
 126         if (rgn_desc->region.space_id == ACPI_ADR_SPACE_SMBUS) {
 127
 128                 /* SMBus has a non-linear address space */
 129
 130                 return_ACPI_STATUS(AE_OK);
 131         }
 132 #ifdef ACPI_UNDER_DEVELOPMENT
 133         /*
 134          * If the Field access is any_acc, we can now compute the optimal
 135          * access (because we know know the length of the parent region)
 136          */
 137         if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 138                 if (ACPI_FAILURE(status)) {
 139                         return_ACPI_STATUS(status);
 140                 }
 141         }
 142 #endif
 143
 144         /*
 145          * Validate the request.  The entire request from the byte offset for a
 146          * length of one field datum (access width) must fit within the region.
 147          * (Region length is specified in bytes)
 148          */
 149         if (rgn_desc->region.length <
 150             (obj_desc->common_field.base_byte_offset +
 151              field_datum_byte_offset +
 152              obj_desc->common_field.access_byte_width)) {
 153                 if (acpi_gbl_enable_interpreter_slack) {
 154                         /*
 155                          * Slack mode only:  We will go ahead and allow access to this
 156                          * field if it is within the region length rounded up to the next
 157                          * access width boundary. acpi_size cast for 64-bit compile.
 158                          */
 159                         if (ACPI_ROUND_UP(rgn_desc->region.length,
 160                                           obj_desc->common_field.
 161                                           access_byte_width) >=
 162                             ((acpi_size) obj_desc->common_field.
 163                              base_byte_offset +
 164                              obj_desc->common_field.access_byte_width +
 165                              field_datum_byte_offset)) {
 166                                 return_ACPI_STATUS(AE_OK);
 167                         }
 168                 }
 169
 170                 if (rgn_desc->region.length <
 171                     obj_desc->common_field.access_byte_width) {
 172                         /*
 173                          * This is the case where the access_type (acc_word, etc.) is wider
 174                          * than the region itself.  For example, a region of length one
 175                          * byte, and a field with Dword access specified.
 176                          */
 177                         ACPI_ERROR((AE_INFO,
 178                                     "Field [%4.4s] access width (%d bytes) too large for region [%4.4s] (length %X)",
 179                                     acpi_ut_get_node_name(obj_desc->
 180                                                           common_field.node),
 181                                     obj_desc->common_field.access_byte_width,
 182                                     acpi_ut_get_node_name(rgn_desc->region.
 183                                                           node),
 184                                     rgn_desc->region.length));
 185                 }
 186
 187                 /*
 188                  * Offset rounded up to next multiple of field width
 189                  * exceeds region length, indicate an error
 190                  */
 191                 ACPI_ERROR((AE_INFO,
 192                             "Field [%4.4s] Base+Offset+Width %X+%X+%X is beyond end of region [%4.4s] (length %X)",
 193                             acpi_ut_get_node_name(obj_desc->common_field.node),
 194                             obj_desc->common_field.base_byte_offset,
 195                             field_datum_byte_offset,
 196                             obj_desc->common_field.access_byte_width,
 197                             acpi_ut_get_node_name(rgn_desc->region.node),
 198                             rgn_desc->region.length));
 199
 200                 return_ACPI_STATUS(AE_AML_REGION_LIMIT);
 201         }
 202
 203         return_ACPI_STATUS(AE_OK);
 204 }
 205
 206 /*******************************************************************************
 207  *
 208  * FUNCTION:    acpi_ex_access_region
 209  *
 210  * PARAMETERS:  obj_desc                - Field to be read
 211  *              field_datum_byte_offset - Byte offset of this datum within the
 212  *                                        parent field
 213  *              Value                   - Where to store value (must at least
 214  *                                        the size of acpi_integer)
 215  *              Function                - Read or Write flag plus other region-
 216  *                                        dependent flags
 217  *
 218  * RETURN:      Status
 219  *
 220  * DESCRIPTION: Read or Write a single field datum to an Operation Region.
 221  *
 222  ******************************************************************************/
 223
 224 acpi_status
 225 acpi_ex_access_region(union acpi_operand_object *obj_desc,
 226                       u32 field_datum_byte_offset,
 227                       acpi_integer * value, u32 function)
 228 {
 229         acpi_status status;
 230         union acpi_operand_object *rgn_desc;
 231         u32 region_offset;
 232
 233         ACPI_FUNCTION_TRACE(ex_access_region);
 234
 235         /*
 236          * Ensure that the region operands are fully evaluated and verify
 237          * the validity of the request
 238          */
 239         status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset);
 240         if (ACPI_FAILURE(status)) {
 241                 return_ACPI_STATUS(status);
 242         }
 243
 244         /*
 245          * The physical address of this field datum is:
 246          *
 247          * 1) The base of the region, plus
 248          * 2) The base offset of the field, plus
 249          * 3) The current offset into the field
 250          */
 251         rgn_desc = obj_desc->common_field.region_obj;
 252         region_offset =
 253             obj_desc->common_field.base_byte_offset + field_datum_byte_offset;
 254
 255         if ((function & ACPI_IO_MASK) == ACPI_READ) {
 256                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
 257         } else {
 258                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
 259         }
 260
 261         ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
 262                               " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n",
 263                               acpi_ut_get_region_name(rgn_desc->region.
 264                                                       space_id),
 265                               rgn_desc->region.space_id,
 266                               obj_desc->common_field.access_byte_width,
 267                               obj_desc->common_field.base_byte_offset,
 268                               field_datum_byte_offset, ACPI_CAST_PTR(void,
 269                                                                      (rgn_desc->
 270                                                                       region.
 271                                                                       address +
 272                                                                       region_offset))));
 273
 274         /* Invoke the appropriate address_space/op_region handler */
 275
 276         status =
 277             acpi_ev_address_space_dispatch(rgn_desc, function, region_offset,
 278                                            ACPI_MUL_8(obj_desc->common_field.
 279                                                       access_byte_width),
 280                                            value);
 281
 282         if (ACPI_FAILURE(status)) {
 283                 if (status == AE_NOT_IMPLEMENTED) {
 284                         ACPI_ERROR((AE_INFO,
 285                                     "Region %s(%X) not implemented",
 286                                     acpi_ut_get_region_name(rgn_desc->region.
 287                                                             space_id),
 288                                     rgn_desc->region.space_id));
 289                 } else if (status == AE_NOT_EXIST) {
 290                         ACPI_ERROR((AE_INFO,
 291                                     "Region %s(%X) has no handler",
 292                                     acpi_ut_get_region_name(rgn_desc->region.
 293                                                             space_id),
 294                                     rgn_desc->region.space_id));
 295                 }
 296         }
 297
 298         return_ACPI_STATUS(status);
 299 }
 300
 301 /*******************************************************************************
 302  *
 303  * FUNCTION:    acpi_ex_register_overflow
 304  *
 305  * PARAMETERS:  obj_desc                - Register(Field) to be written
 306  *              Value                   - Value to be stored
 307  *
 308  * RETURN:      TRUE if value overflows the field, FALSE otherwise
 309  *
 310  * DESCRIPTION: Check if a value is out of range of the field being written.
 311  *              Used to check if the values written to Index and Bank registers
 312  *              are out of range.  Normally, the value is simply truncated
 313  *              to fit the field, but this case is most likely a serious
 314  *              coding error in the ASL.
 315  *
 316  ******************************************************************************/
 317
 318 static u8
 319 acpi_ex_register_overflow(union acpi_operand_object *obj_desc,
 320                           acpi_integer value)
 321 {
 322
 323         if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
 324                 /*
 325                  * The field is large enough to hold the maximum integer, so we can
 326                  * never overflow it.
 327                  */
 328                 return (FALSE);
 329         }
 330
 331         if (value >= ((acpi_integer) 1 << obj_desc->common_field.bit_length)) {
 332                 /*
 333                  * The Value is larger than the maximum value that can fit into
 334                  * the register.
 335                  */
 336                 return (TRUE);
 337         }
 338
 339         /* The Value will fit into the field with no truncation */
 340
 341         return (FALSE);
 342 }
 343
 344 /*******************************************************************************
 345  *
 346  * FUNCTION:    acpi_ex_field_datum_io
 347  *
 348  * PARAMETERS:  obj_desc                - Field to be read
 349  *              field_datum_byte_offset - Byte offset of this datum within the
 350  *                                        parent field
 351  *              Value                   - Where to store value (must be 64 bits)
 352  *              read_write              - Read or Write flag
 353  *
 354  * RETURN:      Status
 355  *
 356  * DESCRIPTION: Read or Write a single datum of a field.  The field_type is
 357  *              demultiplexed here to handle the different types of fields
 358  *              (buffer_field, region_field, index_field, bank_field)
 359  *
 360  ******************************************************************************/
 361
 362 static acpi_status
 363 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
 364                        u32 field_datum_byte_offset,
 365                        acpi_integer * value, u32 read_write)
 366 {
 367         acpi_status status;
 368         acpi_integer local_value;
 369
 370         ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
 371
 372         if (read_write == ACPI_READ) {
 373                 if (!value) {
 374                         local_value = 0;
 375
 376                         /* To support reads without saving return value */
 377                         value = &local_value;
 378                 }
 379
 380                 /* Clear the entire return buffer first, [Very Important!] */
 381
 382                 *value = 0;
 383         }
 384
 385         /*
 386          * The four types of fields are:
 387          *
 388          * buffer_field - Read/write from/to a Buffer
 389          * region_field - Read/write from/to a Operation Region.
 390          * bank_field  - Write to a Bank Register, then read/write from/to an
 391          *               operation_region
 392          * index_field - Write to an Index Register, then read/write from/to a
 393          *               Data Register
 394          */
 395         switch (obj_desc->common.type) {
 396         case ACPI_TYPE_BUFFER_FIELD:
 397                 /*
 398                  * If the buffer_field arguments have not been previously evaluated,
 399                  * evaluate them now and save the results.
 400                  */
 401                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 402                         status = acpi_ds_get_buffer_field_arguments(obj_desc);
 403                         if (ACPI_FAILURE(status)) {
 404                                 return_ACPI_STATUS(status);
 405                         }
 406                 }
 407
 408                 if (read_write == ACPI_READ) {
 409                         /*
 410                          * Copy the data from the source buffer.
 411                          * Length is the field width in bytes.
 412                          */
 413                         ACPI_MEMCPY(value,
 414                                     (obj_desc->buffer_field.buffer_obj)->buffer.
 415                                     pointer +
 416                                     obj_desc->buffer_field.base_byte_offset +
 417                                     field_datum_byte_offset,
 418                                     obj_desc->common_field.access_byte_width);
 419                 } else {
 420                         /*
 421                          * Copy the data to the target buffer.
 422                          * Length is the field width in bytes.
 423                          */
 424                         ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer.
 425                                     pointer +
 426                                     obj_desc->buffer_field.base_byte_offset +
 427                                     field_datum_byte_offset, value,
 428                                     obj_desc->common_field.access_byte_width);
 429                 }
 430
 431                 status = AE_OK;
 432                 break;
 433
 434         case ACPI_TYPE_LOCAL_BANK_FIELD:
 435
 436                 /*
 437                  * Ensure that the bank_value is not beyond the capacity of
 438                  * the register
 439                  */
 440                 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
 441                                               (acpi_integer) obj_desc->
 442                                               bank_field.value)) {
 443                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
 444                 }
 445
 446                 /*
 447                  * For bank_fields, we must write the bank_value to the bank_register
 448                  * (itself a region_field) before we can access the data.
 449                  */
 450                 status =
 451                     acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
 452                                               &obj_desc->bank_field.value,
 453                                               sizeof(obj_desc->bank_field.
 454                                                      value));
 455                 if (ACPI_FAILURE(status)) {
 456                         return_ACPI_STATUS(status);
 457                 }
 458
 459                 /*
 460                  * Now that the Bank has been selected, fall through to the
 461                  * region_field case and write the datum to the Operation Region
 462                  */
 463
 464                 /*lint -fallthrough */
 465
 466         case ACPI_TYPE_LOCAL_REGION_FIELD:
 467                 /*
 468                  * For simple region_fields, we just directly access the owning
 469                  * Operation Region.
 470                  */
 471                 status =
 472                     acpi_ex_access_region(obj_desc, field_datum_byte_offset,
 473                                           value, read_write);
 474                 break;
 475
 476         case ACPI_TYPE_LOCAL_INDEX_FIELD:
 477
 478                 /*
 479                  * Ensure that the index_value is not beyond the capacity of
 480                  * the register
 481                  */
 482                 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
 483                                               (acpi_integer) obj_desc->
 484                                               index_field.value)) {
 485                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
 486                 }
 487
 488                 /* Write the index value to the index_register (itself a region_field) */
 489
 490                 field_datum_byte_offset += obj_desc->index_field.value;
 491
 492                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 493                                   "Write to Index Register: Value %8.8X\n",
 494                                   field_datum_byte_offset));
 495
 496                 status =
 497                     acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
 498                                               &field_datum_byte_offset,
 499                                               sizeof(field_datum_byte_offset));
 500                 if (ACPI_FAILURE(status)) {
 501                         return_ACPI_STATUS(status);
 502                 }
 503
 504                 if (read_write == ACPI_READ) {
 505
 506                         /* Read the datum from the data_register */
 507
 508                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 509                                           "Read from Data Register\n"));
 510
 511                         status =
 512                             acpi_ex_extract_from_field(obj_desc->index_field.
 513                                                        data_obj, value,
 514                                                        sizeof(acpi_integer));
 515                 } else {
 516                         /* Write the datum to the data_register */
 517
 518                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 519                                           "Write to Data Register: Value %8.8X%8.8X\n",
 520                                           ACPI_FORMAT_UINT64(*value)));
 521
 522                         status =
 523                             acpi_ex_insert_into_field(obj_desc->index_field.
 524                                                       data_obj, value,
 525                                                       sizeof(acpi_integer));
 526                 }
 527                 break;
 528
 529         default:
 530
 531                 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %X",
 532                             obj_desc->common.type));
 533                 status = AE_AML_INTERNAL;
 534                 break;
 535         }
 536
 537         if (ACPI_SUCCESS(status)) {
 538                 if (read_write == ACPI_READ) {
 539                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 540                                           "Value Read %8.8X%8.8X, Width %d\n",
 541                                           ACPI_FORMAT_UINT64(*value),
 542                                           obj_desc->common_field.
 543                                           access_byte_width));
 544                 } else {
 545                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 546                                           "Value Written %8.8X%8.8X, Width %d\n",
 547                                           ACPI_FORMAT_UINT64(*value),
 548                                           obj_desc->common_field.
 549                                           access_byte_width));
 550                 }
 551         }
 552
 553         return_ACPI_STATUS(status);
 554 }
 555
 556 /*******************************************************************************
 557  *
 558  * FUNCTION:    acpi_ex_write_with_update_rule
 559  *
 560  * PARAMETERS:  obj_desc                - Field to be written
 561  *              Mask                    - bitmask within field datum
 562  *              field_value             - Value to write
 563  *              field_datum_byte_offset - Offset of datum within field
 564  *
 565  * RETURN:      Status
 566  *
 567  * DESCRIPTION: Apply the field update rule to a field write
 568  *
 569  ******************************************************************************/
 570
 571 acpi_status
 572 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc,
 573                                acpi_integer mask,
 574                                acpi_integer field_value,
 575                                u32 field_datum_byte_offset)
 576 {
 577         acpi_status status = AE_OK;
 578         acpi_integer merged_value;
 579         acpi_integer current_value;
 580
 581         ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask);
 582
 583         /* Start with the new bits  */
 584
 585         merged_value = field_value;
 586
 587         /* If the mask is all ones, we don't need to worry about the update rule */
 588
 589         if (mask != ACPI_INTEGER_MAX) {
 590
 591                 /* Decode the update rule */
 592
 593                 switch (obj_desc->common_field.
 594                         field_flags & AML_FIELD_UPDATE_RULE_MASK) {
 595                 case AML_FIELD_UPDATE_PRESERVE:
 596                         /*
 597                          * Check if update rule needs to be applied (not if mask is all
 598                          * ones)  The left shift drops the bits we want to ignore.
 599                          */
 600                         if ((~mask << (ACPI_MUL_8(sizeof(mask)) -
 601                                        ACPI_MUL_8(obj_desc->common_field.
 602                                                   access_byte_width))) != 0) {
 603                                 /*
 604                                  * Read the current contents of the byte/word/dword containing
 605                                  * the field, and merge with the new field value.
 606                                  */
 607                                 status =
 608                                     acpi_ex_field_datum_io(obj_desc,
 609                                                            field_datum_byte_offset,
 610                                                            &current_value,
 611                                                            ACPI_READ);
 612                                 if (ACPI_FAILURE(status)) {
 613                                         return_ACPI_STATUS(status);
 614                                 }
 615
 616                                 merged_value |= (current_value & ~mask);
 617                         }
 618                         break;
 619
 620                 case AML_FIELD_UPDATE_WRITE_AS_ONES:
 621
 622                         /* Set positions outside the field to all ones */
 623
 624                         merged_value |= ~mask;
 625                         break;
 626
 627                 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
 628
 629                         /* Set positions outside the field to all zeros */
 630
 631                         merged_value &= mask;
 632                         break;
 633
 634                 default:
 635
 636                         ACPI_ERROR((AE_INFO,
 637                                     "Unknown UpdateRule value: %X",
 638                                     (obj_desc->common_field.
 639                                      field_flags &
 640                                      AML_FIELD_UPDATE_RULE_MASK)));
 641                         return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
 642                 }
 643         }
 644
 645         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 646                           "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
 647                           ACPI_FORMAT_UINT64(mask),
 648                           field_datum_byte_offset,
 649                           obj_desc->common_field.access_byte_width,
 650                           ACPI_FORMAT_UINT64(field_value),
 651                           ACPI_FORMAT_UINT64(merged_value)));
 652
 653         /* Write the merged value */
 654
 655         status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset,
 656                                         &merged_value, ACPI_WRITE);
 657
 658         return_ACPI_STATUS(status);
 659 }
 660
 661 /*******************************************************************************
 662  *
 663  * FUNCTION:    acpi_ex_extract_from_field
 664  *
 665  * PARAMETERS:  obj_desc            - Field to be read
 666  *              Buffer              - Where to store the field data
 667  *              buffer_length       - Length of Buffer
 668  *
 669  * RETURN:      Status
 670  *
 671  * DESCRIPTION: Retrieve the current value of the given field
 672  *
 673  ******************************************************************************/
 674
 675 acpi_status
 676 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
 677                            void *buffer, u32 buffer_length)
 678 {
 679         acpi_status status;
 680         acpi_integer raw_datum;
 681         acpi_integer merged_datum;
 682         u32 field_offset = 0;
 683         u32 buffer_offset = 0;
 684         u32 buffer_tail_bits;
 685         u32 datum_count;
 686         u32 field_datum_count;
 687         u32 i;
 688
 689         ACPI_FUNCTION_TRACE(ex_extract_from_field);
 690
 691         /* Validate target buffer and clear it */
 692
 693         if (buffer_length <
 694             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
 695                 ACPI_ERROR((AE_INFO,
 696                             "Field size %X (bits) is too large for buffer (%X)",
 697                             obj_desc->common_field.bit_length, buffer_length));
 698
 699                 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
 700         }
 701         ACPI_MEMSET(buffer, 0, buffer_length);
 702
 703         /* Compute the number of datums (access width data items) */
 704
 705         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
 706                                        obj_desc->common_field.access_bit_width);
 707         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
 708                                              obj_desc->common_field.
 709                                              start_field_bit_offset,
 710                                              obj_desc->common_field.
 711                                              access_bit_width);
 712
 713         /* Priming read from the field */
 714
 715         status =
 716             acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
 717                                    ACPI_READ);
 718         if (ACPI_FAILURE(status)) {
 719                 return_ACPI_STATUS(status);
 720         }
 721         merged_datum =
 722             raw_datum >> obj_desc->common_field.start_field_bit_offset;
 723
 724         /* Read the rest of the field */
 725
 726         for (i = 1; i < field_datum_count; i++) {
 727
 728                 /* Get next input datum from the field */
 729
 730                 field_offset += obj_desc->common_field.access_byte_width;
 731                 status = acpi_ex_field_datum_io(obj_desc, field_offset,
 732                                                 &raw_datum, ACPI_READ);
 733                 if (ACPI_FAILURE(status)) {
 734                         return_ACPI_STATUS(status);
 735                 }
 736
 737                 /*
 738                  * Merge with previous datum if necessary.
 739                  *
 740                  * Note: Before the shift, check if the shift value will be larger than
 741                  * the integer size. If so, there is no need to perform the operation.
 742                  * This avoids the differences in behavior between different compilers
 743                  * concerning shift values larger than the target data width.
 744                  */
 745                 if ((obj_desc->common_field.access_bit_width -
 746                      obj_desc->common_field.start_field_bit_offset) <
 747                     ACPI_INTEGER_BIT_SIZE) {
 748                         merged_datum |=
 749                             raw_datum << (obj_desc->common_field.
 750                                           access_bit_width -
 751                                           obj_desc->common_field.
 752                                           start_field_bit_offset);
 753                 }
 754
 755                 if (i == datum_count) {
 756                         break;
 757                 }
 758
 759                 /* Write merged datum to target buffer */
 760
 761                 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
 762                             ACPI_MIN(obj_desc->common_field.access_byte_width,
 763                                      buffer_length - buffer_offset));
 764
 765                 buffer_offset += obj_desc->common_field.access_byte_width;
 766                 merged_datum =
 767                     raw_datum >> obj_desc->common_field.start_field_bit_offset;
 768         }
 769
 770         /* Mask off any extra bits in the last datum */
 771
 772         buffer_tail_bits = obj_desc->common_field.bit_length %
 773             obj_desc->common_field.access_bit_width;
 774         if (buffer_tail_bits) {
 775                 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
 776         }
 777
 778         /* Write the last datum to the buffer */
 779
 780         ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
 781                     ACPI_MIN(obj_desc->common_field.access_byte_width,
 782                              buffer_length - buffer_offset));
 783
 784         return_ACPI_STATUS(AE_OK);
 785 }
 786
 787 /*******************************************************************************
 788  *
 789  * FUNCTION:    acpi_ex_insert_into_field
 790  *
 791  * PARAMETERS:  obj_desc            - Field to be written
 792  *              Buffer              - Data to be written
 793  *              buffer_length       - Length of Buffer
 794  *
 795  * RETURN:      Status
 796  *
 797  * DESCRIPTION: Store the Buffer contents into the given field
 798  *
 799  ******************************************************************************/
 800
 801 acpi_status
 802 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
 803                           void *buffer, u32 buffer_length)
 804 {
 805         acpi_status status;
 806         acpi_integer mask;
 807         acpi_integer width_mask;
 808         acpi_integer merged_datum;
 809         acpi_integer raw_datum = 0;
 810         u32 field_offset = 0;
 811         u32 buffer_offset = 0;
 812         u32 buffer_tail_bits;
 813         u32 datum_count;
 814         u32 field_datum_count;
 815         u32 i;
 816         u32 required_length;
 817         void *new_buffer;
 818
 819         ACPI_FUNCTION_TRACE(ex_insert_into_field);
 820
 821         /* Validate input buffer */
 822
 823         new_buffer = NULL;
 824         required_length =
 825             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
 826         /*
 827          * We must have a buffer that is at least as long as the field
 828          * we are writing to.  This is because individual fields are
 829          * indivisible and partial writes are not supported -- as per
 830          * the ACPI specification.
 831          */
 832         if (buffer_length < required_length) {
 833
 834                 /* We need to create a new buffer */
 835
 836                 new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
 837                 if (!new_buffer) {
 838                         return_ACPI_STATUS(AE_NO_MEMORY);
 839                 }
 840
 841                 /*
 842                  * Copy the original data to the new buffer, starting
 843                  * at Byte zero.  All unused (upper) bytes of the
 844                  * buffer will be 0.
 845                  */
 846                 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length);
 847                 buffer = new_buffer;
 848                 buffer_length = required_length;
 849         }
 850
 851         /*
 852          * Create the bitmasks used for bit insertion.
 853          * Note: This if/else is used to bypass compiler differences with the
 854          * shift operator
 855          */
 856         if (obj_desc->common_field.access_bit_width == ACPI_INTEGER_BIT_SIZE) {
 857                 width_mask = ACPI_INTEGER_MAX;
 858         } else {
 859                 width_mask =
 860                     ACPI_MASK_BITS_ABOVE(obj_desc->common_field.
 861                                          access_bit_width);
 862         }
 863
 864         mask = width_mask &
 865             ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
 866
 867         /* Compute the number of datums (access width data items) */
 868
 869         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
 870                                        obj_desc->common_field.access_bit_width);
 871
 872         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
 873                                              obj_desc->common_field.
 874                                              start_field_bit_offset,
 875                                              obj_desc->common_field.
 876                                              access_bit_width);
 877
 878         /* Get initial Datum from the input buffer */
 879
 880         ACPI_MEMCPY(&raw_datum, buffer,
 881                     ACPI_MIN(obj_desc->common_field.access_byte_width,
 882                              buffer_length - buffer_offset));
 883
 884         merged_datum =
 885             raw_datum << obj_desc->common_field.start_field_bit_offset;
 886
 887         /* Write the entire field */
 888
 889         for (i = 1; i < field_datum_count; i++) {
 890
 891                 /* Write merged datum to the target field */
 892
 893                 merged_datum &= mask;
 894                 status = acpi_ex_write_with_update_rule(obj_desc, mask,
 895                                                         merged_datum,
 896                                                         field_offset);
 897                 if (ACPI_FAILURE(status)) {
 898                         goto exit;
 899                 }
 900
 901                 field_offset += obj_desc->common_field.access_byte_width;
 902
 903                 /*
 904                  * Start new output datum by merging with previous input datum
 905                  * if necessary.
 906                  *
 907                  * Note: Before the shift, check if the shift value will be larger than
 908                  * the integer size. If so, there is no need to perform the operation.
 909                  * This avoids the differences in behavior between different compilers
 910                  * concerning shift values larger than the target data width.
 911                  */
 912                 if ((obj_desc->common_field.access_bit_width -
 913                      obj_desc->common_field.start_field_bit_offset) <
 914                     ACPI_INTEGER_BIT_SIZE) {
 915                         merged_datum =
 916                             raw_datum >> (obj_desc->common_field.
 917                                           access_bit_width -
 918                                           obj_desc->common_field.
 919                                           start_field_bit_offset);
 920                 } else {
 921                         merged_datum = 0;
 922                 }
 923
 924                 mask = width_mask;
 925
 926                 if (i == datum_count) {
 927                         break;
 928                 }
 929
 930                 /* Get the next input datum from the buffer */
 931
 932                 buffer_offset += obj_desc->common_field.access_byte_width;
 933                 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset,
 934                             ACPI_MIN(obj_desc->common_field.access_byte_width,
 935                                      buffer_length - buffer_offset));
 936                 merged_datum |=
 937                     raw_datum << obj_desc->common_field.start_field_bit_offset;
 938         }
 939
 940         /* Mask off any extra bits in the last datum */
 941
 942         buffer_tail_bits = (obj_desc->common_field.bit_length +
 943                             obj_desc->common_field.start_field_bit_offset) %
 944             obj_desc->common_field.access_bit_width;
 945         if (buffer_tail_bits) {
 946                 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
 947         }
 948
 949         /* Write the last datum to the field */
 950
 951         merged_datum &= mask;
 952         status = acpi_ex_write_with_update_rule(obj_desc,
 953                                                 mask, merged_datum,
 954                                                 field_offset);
 955
 956       exit:
 957         /* Free temporary buffer if we used one */
 958
 959         if (new_buffer) {
 960                 ACPI_FREE(new_buffer);
 961         }
 962         return_ACPI_STATUS(status);
 963 }