Pileus Git - ~andy/linux/blob - drivers/acpi/acpica/exfldio.c

   1 /******************************************************************************
   2  *
   3  * Module Name: exfldio - Aml Field I/O
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2011, Intel Corp.
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions, and the following disclaimer,
  16  *    without modification.
  17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  18  *    substantially similar to the "NO WARRANTY" disclaimer below
  19  *    ("Disclaimer") and any redistribution must be conditioned upon
  20  *    including a substantially similar Disclaimer requirement for further
  21  *    binary redistribution.
  22  * 3. Neither the names of the above-listed copyright holders nor the names
  23  *    of any contributors may be used to endorse or promote products derived
  24  *    from this software without specific prior written permission.
  25  *
  26  * Alternatively, this software may be distributed under the terms of the
  27  * GNU General Public License ("GPL") version 2 as published by the Free
  28  * Software Foundation.
  29  *
  30  * NO WARRANTY
  31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  41  * POSSIBILITY OF SUCH DAMAGES.
  42  */
  43
  44 #include <acpi/acpi.h>
  45 #include "accommon.h"
  46 #include "acinterp.h"
  47 #include "amlcode.h"
  48 #include "acevents.h"
  49 #include "acdispat.h"
  50
  51 #define _COMPONENT          ACPI_EXECUTER
  52 ACPI_MODULE_NAME("exfldio")
  53
  54 /* Local prototypes */
  55 static acpi_status
  56 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
  57                        u32 field_datum_byte_offset,
  58                        u64 *value, u32 read_write);
  59
  60 static u8
  61 acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 value);
  62
  63 static acpi_status
  64 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
  65                      u32 field_datum_byte_offset);
  66
  67 /*******************************************************************************
  68  *
  69  * FUNCTION:    acpi_ex_setup_region
  70  *
  71  * PARAMETERS:  obj_desc                - Field to be read or written
  72  *              field_datum_byte_offset - Byte offset of this datum within the
  73  *                                        parent field
  74  *
  75  * RETURN:      Status
  76  *
  77  * DESCRIPTION: Common processing for acpi_ex_extract_from_field and
  78  *              acpi_ex_insert_into_field. Initialize the Region if necessary and
  79  *              validate the request.
  80  *
  81  ******************************************************************************/
  82
  83 static acpi_status
  84 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
  85                      u32 field_datum_byte_offset)
  86 {
  87         acpi_status status = AE_OK;
  88         union acpi_operand_object *rgn_desc;
  89         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 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_IPMI) {
 139
 140                 /* SMBus or IPMI has a non-linear address space */
 141
 142                 return_ACPI_STATUS(AE_OK);
 143         }
 144 #ifdef ACPI_UNDER_DEVELOPMENT
 145         /*
 146          * If the Field access is any_acc, we can now compute the optimal
 147          * access (because we know know the length of the parent region)
 148          */
 149         if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 150                 if (ACPI_FAILURE(status)) {
 151                         return_ACPI_STATUS(status);
 152                 }
 153         }
 154 #endif
 155
 156         /*
 157          * Validate the request.  The entire request from the byte offset for a
 158          * length of one field datum (access width) must fit within the region.
 159          * (Region length is specified in bytes)
 160          */
 161         if (rgn_desc->region.length <
 162             (obj_desc->common_field.base_byte_offset + field_datum_byte_offset +
 163              obj_desc->common_field.access_byte_width)) {
 164                 if (acpi_gbl_enable_interpreter_slack) {
 165                         /*
 166                          * Slack mode only:  We will go ahead and allow access to this
 167                          * field if it is within the region length rounded up to the next
 168                          * access width boundary. acpi_size cast for 64-bit compile.
 169                          */
 170                         if (ACPI_ROUND_UP(rgn_desc->region.length,
 171                                           obj_desc->common_field.
 172                                           access_byte_width) >=
 173                             ((acpi_size) obj_desc->common_field.
 174                              base_byte_offset +
 175                              obj_desc->common_field.access_byte_width +
 176                              field_datum_byte_offset)) {
 177                                 return_ACPI_STATUS(AE_OK);
 178                         }
 179                 }
 180
 181                 if (rgn_desc->region.length <
 182                     obj_desc->common_field.access_byte_width) {
 183                         /*
 184                          * This is the case where the access_type (acc_word, etc.) is wider
 185                          * than the region itself.  For example, a region of length one
 186                          * byte, and a field with Dword access specified.
 187                          */
 188                         ACPI_ERROR((AE_INFO,
 189                                     "Field [%4.4s] access width (%u bytes) too large for region [%4.4s] (length %u)",
 190                                     acpi_ut_get_node_name(obj_desc->
 191                                                           common_field.node),
 192                                     obj_desc->common_field.access_byte_width,
 193                                     acpi_ut_get_node_name(rgn_desc->region.
 194                                                           node),
 195                                     rgn_desc->region.length));
 196                 }
 197
 198                 /*
 199                  * Offset rounded up to next multiple of field width
 200                  * exceeds region length, indicate an error
 201                  */
 202                 ACPI_ERROR((AE_INFO,
 203                             "Field [%4.4s] Base+Offset+Width %u+%u+%u is beyond end of region [%4.4s] (length %u)",
 204                             acpi_ut_get_node_name(obj_desc->common_field.node),
 205                             obj_desc->common_field.base_byte_offset,
 206                             field_datum_byte_offset,
 207                             obj_desc->common_field.access_byte_width,
 208                             acpi_ut_get_node_name(rgn_desc->region.node),
 209                             rgn_desc->region.length));
 210
 211                 return_ACPI_STATUS(AE_AML_REGION_LIMIT);
 212         }
 213
 214         return_ACPI_STATUS(AE_OK);
 215 }
 216
 217 /*******************************************************************************
 218  *
 219  * FUNCTION:    acpi_ex_access_region
 220  *
 221  * PARAMETERS:  obj_desc                - Field to be read
 222  *              field_datum_byte_offset - Byte offset of this datum within the
 223  *                                        parent field
 224  *              Value                   - Where to store value (must at least
 225  *                                        64 bits)
 226  *              Function                - Read or Write flag plus other region-
 227  *                                        dependent flags
 228  *
 229  * RETURN:      Status
 230  *
 231  * DESCRIPTION: Read or Write a single field datum to an Operation Region.
 232  *
 233  ******************************************************************************/
 234
 235 acpi_status
 236 acpi_ex_access_region(union acpi_operand_object *obj_desc,
 237                       u32 field_datum_byte_offset, u64 *value, u32 function)
 238 {
 239         acpi_status status;
 240         union acpi_operand_object *rgn_desc;
 241         u32 region_offset;
 242
 243         ACPI_FUNCTION_TRACE(ex_access_region);
 244
 245         /*
 246          * Ensure that the region operands are fully evaluated and verify
 247          * the validity of the request
 248          */
 249         status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset);
 250         if (ACPI_FAILURE(status)) {
 251                 return_ACPI_STATUS(status);
 252         }
 253
 254         /*
 255          * The physical address of this field datum is:
 256          *
 257          * 1) The base of the region, plus
 258          * 2) The base offset of the field, plus
 259          * 3) The current offset into the field
 260          */
 261         rgn_desc = obj_desc->common_field.region_obj;
 262         region_offset =
 263             obj_desc->common_field.base_byte_offset + field_datum_byte_offset;
 264
 265         if ((function & ACPI_IO_MASK) == ACPI_READ) {
 266                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
 267         } else {
 268                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
 269         }
 270
 271         ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
 272                               " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n",
 273                               acpi_ut_get_region_name(rgn_desc->region.
 274                                                       space_id),
 275                               rgn_desc->region.space_id,
 276                               obj_desc->common_field.access_byte_width,
 277                               obj_desc->common_field.base_byte_offset,
 278                               field_datum_byte_offset, ACPI_CAST_PTR(void,
 279                                                                      (rgn_desc->
 280                                                                       region.
 281                                                                       address +
 282                                                                       region_offset))));
 283
 284         /* Invoke the appropriate address_space/op_region handler */
 285
 286         status = acpi_ev_address_space_dispatch(rgn_desc, obj_desc,
 287                                                 function, region_offset,
 288                                                 ACPI_MUL_8(obj_desc->
 289                                                            common_field.
 290                                                            access_byte_width),
 291                                                 value);
 292
 293         if (ACPI_FAILURE(status)) {
 294                 if (status == AE_NOT_IMPLEMENTED) {
 295                         ACPI_ERROR((AE_INFO,
 296                                     "Region %s (ID=%u) not implemented",
 297                                     acpi_ut_get_region_name(rgn_desc->region.
 298                                                             space_id),
 299                                     rgn_desc->region.space_id));
 300                 } else if (status == AE_NOT_EXIST) {
 301                         ACPI_ERROR((AE_INFO,
 302                                     "Region %s (ID=%u) has no handler",
 303                                     acpi_ut_get_region_name(rgn_desc->region.
 304                                                             space_id),
 305                                     rgn_desc->region.space_id));
 306                 }
 307         }
 308
 309         return_ACPI_STATUS(status);
 310 }
 311
 312 /*******************************************************************************
 313  *
 314  * FUNCTION:    acpi_ex_register_overflow
 315  *
 316  * PARAMETERS:  obj_desc                - Register(Field) to be written
 317  *              Value                   - Value to be stored
 318  *
 319  * RETURN:      TRUE if value overflows the field, FALSE otherwise
 320  *
 321  * DESCRIPTION: Check if a value is out of range of the field being written.
 322  *              Used to check if the values written to Index and Bank registers
 323  *              are out of range.  Normally, the value is simply truncated
 324  *              to fit the field, but this case is most likely a serious
 325  *              coding error in the ASL.
 326  *
 327  ******************************************************************************/
 328
 329 static u8
 330 acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 value)
 331 {
 332         ACPI_FUNCTION_NAME(ex_register_overflow);
 333
 334         if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
 335                 /*
 336                  * The field is large enough to hold the maximum integer, so we can
 337                  * never overflow it.
 338                  */
 339                 return (FALSE);
 340         }
 341
 342         if (value >= ((u64) 1 << obj_desc->common_field.bit_length)) {
 343                 /*
 344                  * The Value is larger than the maximum value that can fit into
 345                  * the register.
 346                  */
 347                 ACPI_ERROR((AE_INFO,
 348                             "Index value 0x%8.8X%8.8X overflows field width 0x%X",
 349                             ACPI_FORMAT_UINT64(value),
 350                             obj_desc->common_field.bit_length));
 351
 352                 return (TRUE);
 353         }
 354
 355         /* The Value will fit into the field with no truncation */
 356
 357         return (FALSE);
 358 }
 359
 360 /*******************************************************************************
 361  *
 362  * FUNCTION:    acpi_ex_field_datum_io
 363  *
 364  * PARAMETERS:  obj_desc                - Field to be read
 365  *              field_datum_byte_offset - Byte offset of this datum within the
 366  *                                        parent field
 367  *              Value                   - Where to store value (must be 64 bits)
 368  *              read_write              - Read or Write flag
 369  *
 370  * RETURN:      Status
 371  *
 372  * DESCRIPTION: Read or Write a single datum of a field.  The field_type is
 373  *              demultiplexed here to handle the different types of fields
 374  *              (buffer_field, region_field, index_field, bank_field)
 375  *
 376  ******************************************************************************/
 377
 378 static acpi_status
 379 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
 380                        u32 field_datum_byte_offset, u64 *value, u32 read_write)
 381 {
 382         acpi_status status;
 383         u64 local_value;
 384
 385         ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
 386
 387         if (read_write == ACPI_READ) {
 388                 if (!value) {
 389                         local_value = 0;
 390
 391                         /* To support reads without saving return value */
 392                         value = &local_value;
 393                 }
 394
 395                 /* Clear the entire return buffer first, [Very Important!] */
 396
 397                 *value = 0;
 398         }
 399
 400         /*
 401          * The four types of fields are:
 402          *
 403          * buffer_field - Read/write from/to a Buffer
 404          * region_field - Read/write from/to a Operation Region.
 405          * bank_field  - Write to a Bank Register, then read/write from/to an
 406          *               operation_region
 407          * index_field - Write to an Index Register, then read/write from/to a
 408          *               Data Register
 409          */
 410         switch (obj_desc->common.type) {
 411         case ACPI_TYPE_BUFFER_FIELD:
 412                 /*
 413                  * If the buffer_field arguments have not been previously evaluated,
 414                  * evaluate them now and save the results.
 415                  */
 416                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 417                         status = acpi_ds_get_buffer_field_arguments(obj_desc);
 418                         if (ACPI_FAILURE(status)) {
 419                                 return_ACPI_STATUS(status);
 420                         }
 421                 }
 422
 423                 if (read_write == ACPI_READ) {
 424                         /*
 425                          * Copy the data from the source buffer.
 426                          * Length is the field width in bytes.
 427                          */
 428                         ACPI_MEMCPY(value,
 429                                     (obj_desc->buffer_field.buffer_obj)->buffer.
 430                                     pointer +
 431                                     obj_desc->buffer_field.base_byte_offset +
 432                                     field_datum_byte_offset,
 433                                     obj_desc->common_field.access_byte_width);
 434                 } else {
 435                         /*
 436                          * Copy the data to the target buffer.
 437                          * Length is the field width in bytes.
 438                          */
 439                         ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer.
 440                                     pointer +
 441                                     obj_desc->buffer_field.base_byte_offset +
 442                                     field_datum_byte_offset, value,
 443                                     obj_desc->common_field.access_byte_width);
 444                 }
 445
 446                 status = AE_OK;
 447                 break;
 448
 449         case ACPI_TYPE_LOCAL_BANK_FIELD:
 450
 451                 /*
 452                  * Ensure that the bank_value is not beyond the capacity of
 453                  * the register
 454                  */
 455                 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
 456                                               (u64) obj_desc->bank_field.
 457                                               value)) {
 458                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
 459                 }
 460
 461                 /*
 462                  * For bank_fields, we must write the bank_value to the bank_register
 463                  * (itself a region_field) before we can access the data.
 464                  */
 465                 status =
 466                     acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
 467                                               &obj_desc->bank_field.value,
 468                                               sizeof(obj_desc->bank_field.
 469                                                      value));
 470                 if (ACPI_FAILURE(status)) {
 471                         return_ACPI_STATUS(status);
 472                 }
 473
 474                 /*
 475                  * Now that the Bank has been selected, fall through to the
 476                  * region_field case and write the datum to the Operation Region
 477                  */
 478
 479                 /*lint -fallthrough */
 480
 481         case ACPI_TYPE_LOCAL_REGION_FIELD:
 482                 /*
 483                  * For simple region_fields, we just directly access the owning
 484                  * Operation Region.
 485                  */
 486                 status =
 487                     acpi_ex_access_region(obj_desc, field_datum_byte_offset,
 488                                           value, read_write);
 489                 break;
 490
 491         case ACPI_TYPE_LOCAL_INDEX_FIELD:
 492
 493                 /*
 494                  * Ensure that the index_value is not beyond the capacity of
 495                  * the register
 496                  */
 497                 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
 498                                               (u64) obj_desc->index_field.
 499                                               value)) {
 500                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
 501                 }
 502
 503                 /* Write the index value to the index_register (itself a region_field) */
 504
 505                 field_datum_byte_offset += obj_desc->index_field.value;
 506
 507                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 508                                   "Write to Index Register: Value %8.8X\n",
 509                                   field_datum_byte_offset));
 510
 511                 status =
 512                     acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
 513                                               &field_datum_byte_offset,
 514                                               sizeof(field_datum_byte_offset));
 515                 if (ACPI_FAILURE(status)) {
 516                         return_ACPI_STATUS(status);
 517                 }
 518
 519                 if (read_write == ACPI_READ) {
 520
 521                         /* Read the datum from the data_register */
 522
 523                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 524                                           "Read from Data Register\n"));
 525
 526                         status =
 527                             acpi_ex_extract_from_field(obj_desc->index_field.
 528                                                        data_obj, value,
 529                                                        sizeof(u64));
 530                 } else {
 531                         /* Write the datum to the data_register */
 532
 533                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 534                                           "Write to Data Register: Value %8.8X%8.8X\n",
 535                                           ACPI_FORMAT_UINT64(*value)));
 536
 537                         status =
 538                             acpi_ex_insert_into_field(obj_desc->index_field.
 539                                                       data_obj, value,
 540                                                       sizeof(u64));
 541                 }
 542                 break;
 543
 544         default:
 545
 546                 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %u",
 547                             obj_desc->common.type));
 548                 status = AE_AML_INTERNAL;
 549                 break;
 550         }
 551
 552         if (ACPI_SUCCESS(status)) {
 553                 if (read_write == ACPI_READ) {
 554                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 555                                           "Value Read %8.8X%8.8X, Width %u\n",
 556                                           ACPI_FORMAT_UINT64(*value),
 557                                           obj_desc->common_field.
 558                                           access_byte_width));
 559                 } else {
 560                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 561                                           "Value Written %8.8X%8.8X, Width %u\n",
 562                                           ACPI_FORMAT_UINT64(*value),
 563                                           obj_desc->common_field.
 564                                           access_byte_width));
 565                 }
 566         }
 567
 568         return_ACPI_STATUS(status);
 569 }
 570
 571 /*******************************************************************************
 572  *
 573  * FUNCTION:    acpi_ex_write_with_update_rule
 574  *
 575  * PARAMETERS:  obj_desc                - Field to be written
 576  *              Mask                    - bitmask within field datum
 577  *              field_value             - Value to write
 578  *              field_datum_byte_offset - Offset of datum within field
 579  *
 580  * RETURN:      Status
 581  *
 582  * DESCRIPTION: Apply the field update rule to a field write
 583  *
 584  ******************************************************************************/
 585
 586 acpi_status
 587 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc,
 588                                u64 mask,
 589                                u64 field_value, u32 field_datum_byte_offset)
 590 {
 591         acpi_status status = AE_OK;
 592         u64 merged_value;
 593         u64 current_value;
 594
 595         ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask);
 596
 597         /* Start with the new bits  */
 598
 599         merged_value = field_value;
 600
 601         /* If the mask is all ones, we don't need to worry about the update rule */
 602
 603         if (mask != ACPI_UINT64_MAX) {
 604
 605                 /* Decode the update rule */
 606
 607                 switch (obj_desc->common_field.
 608                         field_flags & AML_FIELD_UPDATE_RULE_MASK) {
 609                 case AML_FIELD_UPDATE_PRESERVE:
 610                         /*
 611                          * Check if update rule needs to be applied (not if mask is all
 612                          * ones)  The left shift drops the bits we want to ignore.
 613                          */
 614                         if ((~mask << (ACPI_MUL_8(sizeof(mask)) -
 615                                        ACPI_MUL_8(obj_desc->common_field.
 616                                                   access_byte_width))) != 0) {
 617                                 /*
 618                                  * Read the current contents of the byte/word/dword containing
 619                                  * the field, and merge with the new field value.
 620                                  */
 621                                 status =
 622                                     acpi_ex_field_datum_io(obj_desc,
 623                                                            field_datum_byte_offset,
 624                                                            &current_value,
 625                                                            ACPI_READ);
 626                                 if (ACPI_FAILURE(status)) {
 627                                         return_ACPI_STATUS(status);
 628                                 }
 629
 630                                 merged_value |= (current_value & ~mask);
 631                         }
 632                         break;
 633
 634                 case AML_FIELD_UPDATE_WRITE_AS_ONES:
 635
 636                         /* Set positions outside the field to all ones */
 637
 638                         merged_value |= ~mask;
 639                         break;
 640
 641                 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
 642
 643                         /* Set positions outside the field to all zeros */
 644
 645                         merged_value &= mask;
 646                         break;
 647
 648                 default:
 649
 650                         ACPI_ERROR((AE_INFO,
 651                                     "Unknown UpdateRule value: 0x%X",
 652                                     (obj_desc->common_field.
 653                                      field_flags &
 654                                      AML_FIELD_UPDATE_RULE_MASK)));
 655                         return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
 656                 }
 657         }
 658
 659         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 660                           "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
 661                           ACPI_FORMAT_UINT64(mask),
 662                           field_datum_byte_offset,
 663                           obj_desc->common_field.access_byte_width,
 664                           ACPI_FORMAT_UINT64(field_value),
 665                           ACPI_FORMAT_UINT64(merged_value)));
 666
 667         /* Write the merged value */
 668
 669         status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset,
 670                                         &merged_value, ACPI_WRITE);
 671
 672         return_ACPI_STATUS(status);
 673 }
 674
 675 /*******************************************************************************
 676  *
 677  * FUNCTION:    acpi_ex_extract_from_field
 678  *
 679  * PARAMETERS:  obj_desc            - Field to be read
 680  *              Buffer              - Where to store the field data
 681  *              buffer_length       - Length of Buffer
 682  *
 683  * RETURN:      Status
 684  *
 685  * DESCRIPTION: Retrieve the current value of the given field
 686  *
 687  ******************************************************************************/
 688
 689 acpi_status
 690 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
 691                            void *buffer, u32 buffer_length)
 692 {
 693         acpi_status status;
 694         u64 raw_datum;
 695         u64 merged_datum;
 696         u32 field_offset = 0;
 697         u32 buffer_offset = 0;
 698         u32 buffer_tail_bits;
 699         u32 datum_count;
 700         u32 field_datum_count;
 701         u32 access_bit_width;
 702         u32 i;
 703
 704         ACPI_FUNCTION_TRACE(ex_extract_from_field);
 705
 706         /* Validate target buffer and clear it */
 707
 708         if (buffer_length <
 709             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
 710                 ACPI_ERROR((AE_INFO,
 711                             "Field size %u (bits) is too large for buffer (%u)",
 712                             obj_desc->common_field.bit_length, buffer_length));
 713
 714                 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
 715         }
 716
 717         ACPI_MEMSET(buffer, 0, buffer_length);
 718         access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
 719
 720         /* Handle the simple case here */
 721
 722         if ((obj_desc->common_field.start_field_bit_offset == 0) &&
 723             (obj_desc->common_field.bit_length == access_bit_width)) {
 724                 status = acpi_ex_field_datum_io(obj_desc, 0, buffer, ACPI_READ);
 725                 return_ACPI_STATUS(status);
 726         }
 727
 728 /* TBD: Move to common setup code */
 729
 730         /* Field algorithm is limited to sizeof(u64), truncate if needed */
 731
 732         if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
 733                 obj_desc->common_field.access_byte_width = sizeof(u64);
 734                 access_bit_width = sizeof(u64) * 8;
 735         }
 736
 737         /* Compute the number of datums (access width data items) */
 738
 739         datum_count =
 740             ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
 741                              access_bit_width);
 742
 743         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
 744                                              obj_desc->common_field.
 745                                              start_field_bit_offset,
 746                                              access_bit_width);
 747
 748         /* Priming read from the field */
 749
 750         status =
 751             acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
 752                                    ACPI_READ);
 753         if (ACPI_FAILURE(status)) {
 754                 return_ACPI_STATUS(status);
 755         }
 756         merged_datum =
 757             raw_datum >> obj_desc->common_field.start_field_bit_offset;
 758
 759         /* Read the rest of the field */
 760
 761         for (i = 1; i < field_datum_count; i++) {
 762
 763                 /* Get next input datum from the field */
 764
 765                 field_offset += obj_desc->common_field.access_byte_width;
 766                 status = acpi_ex_field_datum_io(obj_desc, field_offset,
 767                                                 &raw_datum, ACPI_READ);
 768                 if (ACPI_FAILURE(status)) {
 769                         return_ACPI_STATUS(status);
 770                 }
 771
 772                 /*
 773                  * Merge with previous datum if necessary.
 774                  *
 775                  * Note: Before the shift, check if the shift value will be larger than
 776                  * the integer size. If so, there is no need to perform the operation.
 777                  * This avoids the differences in behavior between different compilers
 778                  * concerning shift values larger than the target data width.
 779                  */
 780                 if (access_bit_width -
 781                     obj_desc->common_field.start_field_bit_offset <
 782                     ACPI_INTEGER_BIT_SIZE) {
 783                         merged_datum |=
 784                             raw_datum << (access_bit_width -
 785                                           obj_desc->common_field.
 786                                           start_field_bit_offset);
 787                 }
 788
 789                 if (i == datum_count) {
 790                         break;
 791                 }
 792
 793                 /* Write merged datum to target buffer */
 794
 795                 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
 796                             ACPI_MIN(obj_desc->common_field.access_byte_width,
 797                                      buffer_length - buffer_offset));
 798
 799                 buffer_offset += obj_desc->common_field.access_byte_width;
 800                 merged_datum =
 801                     raw_datum >> obj_desc->common_field.start_field_bit_offset;
 802         }
 803
 804         /* Mask off any extra bits in the last datum */
 805
 806         buffer_tail_bits = obj_desc->common_field.bit_length % access_bit_width;
 807         if (buffer_tail_bits) {
 808                 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
 809         }
 810
 811         /* Write the last datum to the buffer */
 812
 813         ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
 814                     ACPI_MIN(obj_desc->common_field.access_byte_width,
 815                              buffer_length - buffer_offset));
 816
 817         return_ACPI_STATUS(AE_OK);
 818 }
 819
 820 /*******************************************************************************
 821  *
 822  * FUNCTION:    acpi_ex_insert_into_field
 823  *
 824  * PARAMETERS:  obj_desc            - Field to be written
 825  *              Buffer              - Data to be written
 826  *              buffer_length       - Length of Buffer
 827  *
 828  * RETURN:      Status
 829  *
 830  * DESCRIPTION: Store the Buffer contents into the given field
 831  *
 832  ******************************************************************************/
 833
 834 acpi_status
 835 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
 836                           void *buffer, u32 buffer_length)
 837 {
 838         void *new_buffer;
 839         acpi_status status;
 840         u64 mask;
 841         u64 width_mask;
 842         u64 merged_datum;
 843         u64 raw_datum = 0;
 844         u32 field_offset = 0;
 845         u32 buffer_offset = 0;
 846         u32 buffer_tail_bits;
 847         u32 datum_count;
 848         u32 field_datum_count;
 849         u32 access_bit_width;
 850         u32 required_length;
 851         u32 i;
 852
 853         ACPI_FUNCTION_TRACE(ex_insert_into_field);
 854
 855         /* Validate input buffer */
 856
 857         new_buffer = NULL;
 858         required_length =
 859             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
 860         /*
 861          * We must have a buffer that is at least as long as the field
 862          * we are writing to.  This is because individual fields are
 863          * indivisible and partial writes are not supported -- as per
 864          * the ACPI specification.
 865          */
 866         if (buffer_length < required_length) {
 867
 868                 /* We need to create a new buffer */
 869
 870                 new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
 871                 if (!new_buffer) {
 872                         return_ACPI_STATUS(AE_NO_MEMORY);
 873                 }
 874
 875                 /*
 876                  * Copy the original data to the new buffer, starting
 877                  * at Byte zero.  All unused (upper) bytes of the
 878                  * buffer will be 0.
 879                  */
 880                 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length);
 881                 buffer = new_buffer;
 882                 buffer_length = required_length;
 883         }
 884
 885 /* TBD: Move to common setup code */
 886
 887         /* Algo is limited to sizeof(u64), so cut the access_byte_width */
 888         if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
 889                 obj_desc->common_field.access_byte_width = sizeof(u64);
 890         }
 891
 892         access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
 893
 894         /*
 895          * Create the bitmasks used for bit insertion.
 896          * Note: This if/else is used to bypass compiler differences with the
 897          * shift operator
 898          */
 899         if (access_bit_width == ACPI_INTEGER_BIT_SIZE) {
 900                 width_mask = ACPI_UINT64_MAX;
 901         } else {
 902                 width_mask = ACPI_MASK_BITS_ABOVE(access_bit_width);
 903         }
 904
 905         mask = width_mask &
 906             ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
 907
 908         /* Compute the number of datums (access width data items) */
 909
 910         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
 911                                        access_bit_width);
 912
 913         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
 914                                              obj_desc->common_field.
 915                                              start_field_bit_offset,
 916                                              access_bit_width);
 917
 918         /* Get initial Datum from the input buffer */
 919
 920         ACPI_MEMCPY(&raw_datum, buffer,
 921                     ACPI_MIN(obj_desc->common_field.access_byte_width,
 922                              buffer_length - buffer_offset));
 923
 924         merged_datum =
 925             raw_datum << obj_desc->common_field.start_field_bit_offset;
 926
 927         /* Write the entire field */
 928
 929         for (i = 1; i < field_datum_count; i++) {
 930
 931                 /* Write merged datum to the target field */
 932
 933                 merged_datum &= mask;
 934                 status = acpi_ex_write_with_update_rule(obj_desc, mask,
 935                                                         merged_datum,
 936                                                         field_offset);
 937                 if (ACPI_FAILURE(status)) {
 938                         goto exit;
 939                 }
 940
 941                 field_offset += obj_desc->common_field.access_byte_width;
 942
 943                 /*
 944                  * Start new output datum by merging with previous input datum
 945                  * if necessary.
 946                  *
 947                  * Note: Before the shift, check if the shift value will be larger than
 948                  * the integer size. If so, there is no need to perform the operation.
 949                  * This avoids the differences in behavior between different compilers
 950                  * concerning shift values larger than the target data width.
 951                  */
 952                 if ((access_bit_width -
 953                      obj_desc->common_field.start_field_bit_offset) <
 954                     ACPI_INTEGER_BIT_SIZE) {
 955                         merged_datum =
 956                             raw_datum >> (access_bit_width -
 957                                           obj_desc->common_field.
 958                                           start_field_bit_offset);
 959                 } else {
 960                         merged_datum = 0;
 961                 }
 962
 963                 mask = width_mask;
 964
 965                 if (i == datum_count) {
 966                         break;
 967                 }
 968
 969                 /* Get the next input datum from the buffer */
 970
 971                 buffer_offset += obj_desc->common_field.access_byte_width;
 972                 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset,
 973                             ACPI_MIN(obj_desc->common_field.access_byte_width,
 974                                      buffer_length - buffer_offset));
 975
 976                 merged_datum |=
 977                     raw_datum << obj_desc->common_field.start_field_bit_offset;
 978         }
 979
 980         /* Mask off any extra bits in the last datum */
 981
 982         buffer_tail_bits = (obj_desc->common_field.bit_length +
 983                             obj_desc->common_field.start_field_bit_offset) %
 984             access_bit_width;
 985         if (buffer_tail_bits) {
 986                 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
 987         }
 988
 989         /* Write the last datum to the field */
 990
 991         merged_datum &= mask;
 992         status = acpi_ex_write_with_update_rule(obj_desc,
 993                                                 mask, merged_datum,
 994                                                 field_offset);
 995
 996       exit:
 997         /* Free temporary buffer if we used one */
 998
 999         if (new_buffer) {
1000                 ACPI_FREE(new_buffer);
1001         }
1002         return_ACPI_STATUS(status);
1003 }