drivers/acpi/acpica/exfldio.c

   1 /******************************************************************************
   2  *
   3  * Module Name: exfldio - Aml Field I/O
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2013, Intel Corp.
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions, and the following disclaimer,
  16  *    without modification.
  17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  18  *    substantially similar to the "NO WARRANTY" disclaimer below
  19  *    ("Disclaimer") and any redistribution must be conditioned upon
  20  *    including a substantially similar Disclaimer requirement for further
  21  *    binary redistribution.
  22  * 3. Neither the names of the above-listed copyright holders nor the names
  23  *    of any contributors may be used to endorse or promote products derived
  24  *    from this software without specific prior written permission.
  25  *
  26  * Alternatively, this software may be distributed under the terms of the
  27  * GNU General Public License ("GPL") version 2 as published by the Free
  28  * Software Foundation.
  29  *
  30  * NO WARRANTY
  31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  41  * POSSIBILITY OF SUCH DAMAGES.
  42  */
  43
  44 #include <acpi/acpi.h>
  45 #include "accommon.h"
  46 #include "acinterp.h"
  47 #include "amlcode.h"
  48 #include "acevents.h"
  49 #include "acdispat.h"
  50
  51 #define _COMPONENT          ACPI_EXECUTER
  52 ACPI_MODULE_NAME("exfldio")
  53
  54 /* Local prototypes */
  55 static acpi_status
  56 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
  57                        u32 field_datum_byte_offset, u64 *value, u32 read_write);
  58
  59 static u8
  60 acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 value);
  61
  62 static acpi_status
  63 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
  64                      u32 field_datum_byte_offset);
  65
  66 /*******************************************************************************
  67  *
  68  * FUNCTION:    acpi_ex_setup_region
  69  *
  70  * PARAMETERS:  obj_desc                - Field to be read or written
  71  *              field_datum_byte_offset - Byte offset of this datum within the
  72  *                                        parent field
  73  *
  74  * RETURN:      Status
  75  *
  76  * DESCRIPTION: Common processing for acpi_ex_extract_from_field and
  77  *              acpi_ex_insert_into_field. Initialize the Region if necessary and
  78  *              validate the request.
  79  *
  80  ******************************************************************************/
  81
  82 static acpi_status
  83 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
  84                      u32 field_datum_byte_offset)
  85 {
  86         acpi_status status = AE_OK;
  87         union acpi_operand_object *rgn_desc;
  88         u8 space_id;
  89
  90         ACPI_FUNCTION_TRACE_U32(ex_setup_region, field_datum_byte_offset);
  91
  92         rgn_desc = obj_desc->common_field.region_obj;
  93
  94         /* We must have a valid region */
  95
  96         if (rgn_desc->common.type != ACPI_TYPE_REGION) {
  97                 ACPI_ERROR((AE_INFO, "Needed Region, found type 0x%X (%s)",
  98                             rgn_desc->common.type,
  99                             acpi_ut_get_object_type_name(rgn_desc)));
 100
 101                 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
 102         }
 103
 104         space_id = rgn_desc->region.space_id;
 105
 106         /* Validate the Space ID */
 107
 108         if (!acpi_is_valid_space_id(space_id)) {
 109                 ACPI_ERROR((AE_INFO,
 110                             "Invalid/unknown Address Space ID: 0x%2.2X",
 111                             space_id));
 112                 return_ACPI_STATUS(AE_AML_INVALID_SPACE_ID);
 113         }
 114
 115         /*
 116          * If the Region Address and Length have not been previously evaluated,
 117          * evaluate them now and save the results.
 118          */
 119         if (!(rgn_desc->common.flags & AOPOBJ_DATA_VALID)) {
 120                 status = acpi_ds_get_region_arguments(rgn_desc);
 121                 if (ACPI_FAILURE(status)) {
 122                         return_ACPI_STATUS(status);
 123                 }
 124         }
 125
 126         /* Exit if Address/Length have been disallowed by the host OS */
 127
 128         if (rgn_desc->common.flags & AOPOBJ_INVALID) {
 129                 return_ACPI_STATUS(AE_AML_ILLEGAL_ADDRESS);
 130         }
 131
 132         /*
 133          * Exit now for SMBus, GSBus or IPMI address space, it has a non-linear
 134          * address space and the request cannot be directly validated
 135          */
 136         if (space_id == ACPI_ADR_SPACE_SMBUS ||
 137             space_id == ACPI_ADR_SPACE_GSBUS ||
 138             space_id == ACPI_ADR_SPACE_IPMI) {
 139
 140                 /* SMBus or IPMI has a non-linear address space */
 141
 142                 return_ACPI_STATUS(AE_OK);
 143         }
 144 #ifdef ACPI_UNDER_DEVELOPMENT
 145         /*
 146          * If the Field access is any_acc, we can now compute the optimal
 147          * access (because we know know the length of the parent region)
 148          */
 149         if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 150                 if (ACPI_FAILURE(status)) {
 151                         return_ACPI_STATUS(status);
 152                 }
 153         }
 154 #endif
 155
 156         /*
 157          * Validate the request. The entire request from the byte offset for a
 158          * length of one field datum (access width) must fit within the region.
 159          * (Region length is specified in bytes)
 160          */
 161         if (rgn_desc->region.length <
 162             (obj_desc->common_field.base_byte_offset + field_datum_byte_offset +
 163              obj_desc->common_field.access_byte_width)) {
 164                 if (acpi_gbl_enable_interpreter_slack) {
 165                         /*
 166                          * Slack mode only:  We will go ahead and allow access to this
 167                          * field if it is within the region length rounded up to the next
 168                          * access width boundary. acpi_size cast for 64-bit compile.
 169                          */
 170                         if (ACPI_ROUND_UP(rgn_desc->region.length,
 171                                           obj_desc->common_field.
 172                                           access_byte_width) >=
 173                             ((acpi_size) obj_desc->common_field.
 174                              base_byte_offset +
 175                              obj_desc->common_field.access_byte_width +
 176                              field_datum_byte_offset)) {
 177                                 return_ACPI_STATUS(AE_OK);
 178                         }
 179                 }
 180
 181                 if (rgn_desc->region.length <
 182                     obj_desc->common_field.access_byte_width) {
 183                         /*
 184                          * This is the case where the access_type (acc_word, etc.) is wider
 185                          * than the region itself. For example, a region of length one
 186                          * byte, and a field with Dword access specified.
 187                          */
 188                         ACPI_ERROR((AE_INFO,
 189                                     "Field [%4.4s] access width (%u bytes) too large for region [%4.4s] (length %u)",
 190                                     acpi_ut_get_node_name(obj_desc->
 191                                                           common_field.node),
 192                                     obj_desc->common_field.access_byte_width,
 193                                     acpi_ut_get_node_name(rgn_desc->region.
 194                                                           node),
 195                                     rgn_desc->region.length));
 196                 }
 197
 198                 /*
 199                  * Offset rounded up to next multiple of field width
 200                  * exceeds region length, indicate an error
 201                  */
 202                 ACPI_ERROR((AE_INFO,
 203                             "Field [%4.4s] Base+Offset+Width %u+%u+%u is beyond end of region [%4.4s] (length %u)",
 204                             acpi_ut_get_node_name(obj_desc->common_field.node),
 205                             obj_desc->common_field.base_byte_offset,
 206                             field_datum_byte_offset,
 207                             obj_desc->common_field.access_byte_width,
 208                             acpi_ut_get_node_name(rgn_desc->region.node),
 209                             rgn_desc->region.length));
 210
 211                 return_ACPI_STATUS(AE_AML_REGION_LIMIT);
 212         }
 213
 214         return_ACPI_STATUS(AE_OK);
 215 }
 216
 217 /*******************************************************************************
 218  *
 219  * FUNCTION:    acpi_ex_access_region
 220  *
 221  * PARAMETERS:  obj_desc                - Field to be read
 222  *              field_datum_byte_offset - Byte offset of this datum within the
 223  *                                        parent field
 224  *              value                   - Where to store value (must at least
 225  *                                        64 bits)
 226  *              function                - Read or Write flag plus other region-
 227  *                                        dependent flags
 228  *
 229  * RETURN:      Status
 230  *
 231  * DESCRIPTION: Read or Write a single field datum to an Operation Region.
 232  *
 233  ******************************************************************************/
 234
 235 acpi_status
 236 acpi_ex_access_region(union acpi_operand_object *obj_desc,
 237                       u32 field_datum_byte_offset, u64 *value, u32 function)
 238 {
 239         acpi_status status;
 240         union acpi_operand_object *rgn_desc;
 241         u32 region_offset;
 242
 243         ACPI_FUNCTION_TRACE(ex_access_region);
 244
 245         /*
 246          * Ensure that the region operands are fully evaluated and verify
 247          * the validity of the request
 248          */
 249         status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset);
 250         if (ACPI_FAILURE(status)) {
 251                 return_ACPI_STATUS(status);
 252         }
 253
 254         /*
 255          * The physical address of this field datum is:
 256          *
 257          * 1) The base of the region, plus
 258          * 2) The base offset of the field, plus
 259          * 3) The current offset into the field
 260          */
 261         rgn_desc = obj_desc->common_field.region_obj;
 262         region_offset =
 263             obj_desc->common_field.base_byte_offset + field_datum_byte_offset;
 264
 265         if ((function & ACPI_IO_MASK) == ACPI_READ) {
 266                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
 267         } else {
 268                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
 269         }
 270
 271         ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
 272                               " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n",
 273                               acpi_ut_get_region_name(rgn_desc->region.
 274                                                       space_id),
 275                               rgn_desc->region.space_id,
 276                               obj_desc->common_field.access_byte_width,
 277                               obj_desc->common_field.base_byte_offset,
 278                               field_datum_byte_offset, ACPI_CAST_PTR(void,
 279                                                                      (rgn_desc->
 280                                                                       region.
 281                                                                       address +
 282                                                                       region_offset))));
 283
 284         /* Invoke the appropriate address_space/op_region handler */
 285
 286         status = acpi_ev_address_space_dispatch(rgn_desc, obj_desc,
 287                                                 function, region_offset,
 288                                                 ACPI_MUL_8(obj_desc->
 289                                                            common_field.
 290                                                            access_byte_width),
 291                                                 value);
 292
 293         if (ACPI_FAILURE(status)) {
 294                 if (status == AE_NOT_IMPLEMENTED) {
 295                         ACPI_ERROR((AE_INFO,
 296                                     "Region %s (ID=%u) not implemented",
 297                                     acpi_ut_get_region_name(rgn_desc->region.
 298                                                             space_id),
 299                                     rgn_desc->region.space_id));
 300                 } else if (status == AE_NOT_EXIST) {
 301                         ACPI_ERROR((AE_INFO,
 302                                     "Region %s (ID=%u) has no handler",
 303                                     acpi_ut_get_region_name(rgn_desc->region.
 304                                                             space_id),
 305                                     rgn_desc->region.space_id));
 306                 }
 307         }
 308
 309         return_ACPI_STATUS(status);
 310 }
 311
 312 /*******************************************************************************
 313  *
 314  * FUNCTION:    acpi_ex_register_overflow
 315  *
 316  * PARAMETERS:  obj_desc                - Register(Field) to be written
 317  *              value                   - Value to be stored
 318  *
 319  * RETURN:      TRUE if value overflows the field, FALSE otherwise
 320  *
 321  * DESCRIPTION: Check if a value is out of range of the field being written.
 322  *              Used to check if the values written to Index and Bank registers
 323  *              are out of range. Normally, the value is simply truncated
 324  *              to fit the field, but this case is most likely a serious
 325  *              coding error in the ASL.
 326  *
 327  ******************************************************************************/
 328
 329 static u8
 330 acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 value)
 331 {
 332
 333         if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
 334                 /*
 335                  * The field is large enough to hold the maximum integer, so we can
 336                  * never overflow it.
 337                  */
 338                 return (FALSE);
 339         }
 340
 341         if (value >= ((u64) 1 << obj_desc->common_field.bit_length)) {
 342                 /*
 343                  * The Value is larger than the maximum value that can fit into
 344                  * the register.
 345                  */
 346                 ACPI_ERROR((AE_INFO,
 347                             "Index value 0x%8.8X%8.8X overflows field width 0x%X",
 348                             ACPI_FORMAT_UINT64(value),
 349                             obj_desc->common_field.bit_length));
 350
 351                 return (TRUE);
 352         }
 353
 354         /* The Value will fit into the field with no truncation */
 355
 356         return (FALSE);
 357 }
 358
 359 /*******************************************************************************
 360  *
 361  * FUNCTION:    acpi_ex_field_datum_io
 362  *
 363  * PARAMETERS:  obj_desc                - Field to be read
 364  *              field_datum_byte_offset - Byte offset of this datum within the
 365  *                                        parent field
 366  *              value                   - Where to store value (must be 64 bits)
 367  *              read_write              - Read or Write flag
 368  *
 369  * RETURN:      Status
 370  *
 371  * DESCRIPTION: Read or Write a single datum of a field. The field_type is
 372  *              demultiplexed here to handle the different types of fields
 373  *              (buffer_field, region_field, index_field, bank_field)
 374  *
 375  ******************************************************************************/
 376
 377 static acpi_status
 378 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
 379                        u32 field_datum_byte_offset, u64 *value, u32 read_write)
 380 {
 381         acpi_status status;
 382         u64 local_value;
 383
 384         ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
 385
 386         if (read_write == ACPI_READ) {
 387                 if (!value) {
 388                         local_value = 0;
 389
 390                         /* To support reads without saving return value */
 391                         value = &local_value;
 392                 }
 393
 394                 /* Clear the entire return buffer first, [Very Important!] */
 395
 396                 *value = 0;
 397         }
 398
 399         /*
 400          * The four types of fields are:
 401          *
 402          * buffer_field - Read/write from/to a Buffer
 403          * region_field - Read/write from/to a Operation Region.
 404          * bank_field  - Write to a Bank Register, then read/write from/to an
 405          *               operation_region
 406          * index_field - Write to an Index Register, then read/write from/to a
 407          *               Data Register
 408          */
 409         switch (obj_desc->common.type) {
 410         case ACPI_TYPE_BUFFER_FIELD:
 411                 /*
 412                  * If the buffer_field arguments have not been previously evaluated,
 413                  * evaluate them now and save the results.
 414                  */
 415                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 416                         status = acpi_ds_get_buffer_field_arguments(obj_desc);
 417                         if (ACPI_FAILURE(status)) {
 418                                 return_ACPI_STATUS(status);
 419                         }
 420                 }
 421
 422                 if (read_write == ACPI_READ) {
 423                         /*
 424                          * Copy the data from the source buffer.
 425                          * Length is the field width in bytes.
 426                          */
 427                         ACPI_MEMCPY(value,
 428                                     (obj_desc->buffer_field.buffer_obj)->buffer.
 429                                     pointer +
 430                                     obj_desc->buffer_field.base_byte_offset +
 431                                     field_datum_byte_offset,
 432                                     obj_desc->common_field.access_byte_width);
 433                 } else {
 434                         /*
 435                          * Copy the data to the target buffer.
 436                          * Length is the field width in bytes.
 437                          */
 438                         ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer.
 439                                     pointer +
 440                                     obj_desc->buffer_field.base_byte_offset +
 441                                     field_datum_byte_offset, value,
 442                                     obj_desc->common_field.access_byte_width);
 443                 }
 444
 445                 status = AE_OK;
 446                 break;
 447
 448         case ACPI_TYPE_LOCAL_BANK_FIELD:
 449
 450                 /*
 451                  * Ensure that the bank_value is not beyond the capacity of
 452                  * the register
 453                  */
 454                 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
 455                                               (u64) obj_desc->bank_field.
 456                                               value)) {
 457                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
 458                 }
 459
 460                 /*
 461                  * For bank_fields, we must write the bank_value to the bank_register
 462                  * (itself a region_field) before we can access the data.
 463                  */
 464                 status =
 465                     acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
 466                                               &obj_desc->bank_field.value,
 467                                               sizeof(obj_desc->bank_field.
 468                                                      value));
 469                 if (ACPI_FAILURE(status)) {
 470                         return_ACPI_STATUS(status);
 471                 }
 472
 473                 /*
 474                  * Now that the Bank has been selected, fall through to the
 475                  * region_field case and write the datum to the Operation Region
 476                  */
 477
 478                 /*lint -fallthrough */
 479
 480         case ACPI_TYPE_LOCAL_REGION_FIELD:
 481                 /*
 482                  * For simple region_fields, we just directly access the owning
 483                  * Operation Region.
 484                  */
 485                 status =
 486                     acpi_ex_access_region(obj_desc, field_datum_byte_offset,
 487                                           value, read_write);
 488                 break;
 489
 490         case ACPI_TYPE_LOCAL_INDEX_FIELD:
 491
 492                 /*
 493                  * Ensure that the index_value is not beyond the capacity of
 494                  * the register
 495                  */
 496                 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
 497                                               (u64) obj_desc->index_field.
 498                                               value)) {
 499                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
 500                 }
 501
 502                 /* Write the index value to the index_register (itself a region_field) */
 503
 504                 field_datum_byte_offset += obj_desc->index_field.value;
 505
 506                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 507                                   "Write to Index Register: Value %8.8X\n",
 508                                   field_datum_byte_offset));
 509
 510                 status =
 511                     acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
 512                                               &field_datum_byte_offset,
 513                                               sizeof(field_datum_byte_offset));
 514                 if (ACPI_FAILURE(status)) {
 515                         return_ACPI_STATUS(status);
 516                 }
 517
 518                 if (read_write == ACPI_READ) {
 519
 520                         /* Read the datum from the data_register */
 521
 522                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 523                                           "Read from Data Register\n"));
 524
 525                         status =
 526                             acpi_ex_extract_from_field(obj_desc->index_field.
 527                                                        data_obj, value,
 528                                                        sizeof(u64));
 529                 } else {
 530                         /* Write the datum to the data_register */
 531
 532                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 533                                           "Write to Data Register: Value %8.8X%8.8X\n",
 534                                           ACPI_FORMAT_UINT64(*value)));
 535
 536                         status =
 537                             acpi_ex_insert_into_field(obj_desc->index_field.
 538                                                       data_obj, value,
 539                                                       sizeof(u64));
 540                 }
 541                 break;
 542
 543         default:
 544
 545                 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %u",
 546                             obj_desc->common.type));
 547                 status = AE_AML_INTERNAL;
 548                 break;
 549         }
 550
 551         if (ACPI_SUCCESS(status)) {
 552                 if (read_write == ACPI_READ) {
 553                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 554                                           "Value Read %8.8X%8.8X, Width %u\n",
 555                                           ACPI_FORMAT_UINT64(*value),
 556                                           obj_desc->common_field.
 557                                           access_byte_width));
 558                 } else {
 559                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 560                                           "Value Written %8.8X%8.8X, Width %u\n",
 561                                           ACPI_FORMAT_UINT64(*value),
 562                                           obj_desc->common_field.
 563                                           access_byte_width));
 564                 }
 565         }
 566
 567         return_ACPI_STATUS(status);
 568 }
 569
 570 /*******************************************************************************
 571  *
 572  * FUNCTION:    acpi_ex_write_with_update_rule
 573  *
 574  * PARAMETERS:  obj_desc                - Field to be written
 575  *              mask                    - bitmask within field datum
 576  *              field_value             - Value to write
 577  *              field_datum_byte_offset - Offset of datum within field
 578  *
 579  * RETURN:      Status
 580  *
 581  * DESCRIPTION: Apply the field update rule to a field write
 582  *
 583  ******************************************************************************/
 584
 585 acpi_status
 586 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc,
 587                                u64 mask,
 588                                u64 field_value, u32 field_datum_byte_offset)
 589 {
 590         acpi_status status = AE_OK;
 591         u64 merged_value;
 592         u64 current_value;
 593
 594         ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask);
 595
 596         /* Start with the new bits  */
 597
 598         merged_value = field_value;
 599
 600         /* If the mask is all ones, we don't need to worry about the update rule */
 601
 602         if (mask != ACPI_UINT64_MAX) {
 603
 604                 /* Decode the update rule */
 605
 606                 switch (obj_desc->common_field.
 607                         field_flags & AML_FIELD_UPDATE_RULE_MASK) {
 608                 case AML_FIELD_UPDATE_PRESERVE:
 609                         /*
 610                          * Check if update rule needs to be applied (not if mask is all
 611                          * ones)  The left shift drops the bits we want to ignore.
 612                          */
 613                         if ((~mask << (ACPI_MUL_8(sizeof(mask)) -
 614                                        ACPI_MUL_8(obj_desc->common_field.
 615                                                   access_byte_width))) != 0) {
 616                                 /*
 617                                  * Read the current contents of the byte/word/dword containing
 618                                  * the field, and merge with the new field value.
 619                                  */
 620                                 status =
 621                                     acpi_ex_field_datum_io(obj_desc,
 622                                                            field_datum_byte_offset,
 623                                                            &current_value,
 624                                                            ACPI_READ);
 625                                 if (ACPI_FAILURE(status)) {
 626                                         return_ACPI_STATUS(status);
 627                                 }
 628
 629                                 merged_value |= (current_value & ~mask);
 630                         }
 631                         break;
 632
 633                 case AML_FIELD_UPDATE_WRITE_AS_ONES:
 634
 635                         /* Set positions outside the field to all ones */
 636
 637                         merged_value |= ~mask;
 638                         break;
 639
 640                 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
 641
 642                         /* Set positions outside the field to all zeros */
 643
 644                         merged_value &= mask;
 645                         break;
 646
 647                 default:
 648
 649                         ACPI_ERROR((AE_INFO,
 650                                     "Unknown UpdateRule value: 0x%X",
 651                                     (obj_desc->common_field.
 652                                      field_flags &
 653                                      AML_FIELD_UPDATE_RULE_MASK)));
 654                         return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
 655                 }
 656         }
 657
 658         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 659                           "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
 660                           ACPI_FORMAT_UINT64(mask),
 661                           field_datum_byte_offset,
 662                           obj_desc->common_field.access_byte_width,
 663                           ACPI_FORMAT_UINT64(field_value),
 664                           ACPI_FORMAT_UINT64(merged_value)));
 665
 666         /* Write the merged value */
 667
 668         status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset,
 669                                         &merged_value, ACPI_WRITE);
 670
 671         return_ACPI_STATUS(status);
 672 }
 673
 674 /*******************************************************************************
 675  *
 676  * FUNCTION:    acpi_ex_extract_from_field
 677  *
 678  * PARAMETERS:  obj_desc            - Field to be read
 679  *              buffer              - Where to store the field data
 680  *              buffer_length       - Length of Buffer
 681  *
 682  * RETURN:      Status
 683  *
 684  * DESCRIPTION: Retrieve the current value of the given field
 685  *
 686  ******************************************************************************/
 687
 688 acpi_status
 689 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
 690                            void *buffer, u32 buffer_length)
 691 {
 692         acpi_status status;
 693         u64 raw_datum;
 694         u64 merged_datum;
 695         u32 field_offset = 0;
 696         u32 buffer_offset = 0;
 697         u32 buffer_tail_bits;
 698         u32 datum_count;
 699         u32 field_datum_count;
 700         u32 access_bit_width;
 701         u32 i;
 702
 703         ACPI_FUNCTION_TRACE(ex_extract_from_field);
 704
 705         /* Validate target buffer and clear it */
 706
 707         if (buffer_length <
 708             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
 709                 ACPI_ERROR((AE_INFO,
 710                             "Field size %u (bits) is too large for buffer (%u)",
 711                             obj_desc->common_field.bit_length, buffer_length));
 712
 713                 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
 714         }
 715
 716         ACPI_MEMSET(buffer, 0, buffer_length);
 717         access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
 718
 719         /* Handle the simple case here */
 720
 721         if ((obj_desc->common_field.start_field_bit_offset == 0) &&
 722             (obj_desc->common_field.bit_length == access_bit_width)) {
 723                 if (buffer_length >= sizeof(u64)) {
 724                         status =
 725                             acpi_ex_field_datum_io(obj_desc, 0, buffer,
 726                                                    ACPI_READ);
 727                 } else {
 728                         /* Use raw_datum (u64) to handle buffers < 64 bits */
 729
 730                         status =
 731                             acpi_ex_field_datum_io(obj_desc, 0, &raw_datum,
 732                                                    ACPI_READ);
 733                         ACPI_MEMCPY(buffer, &raw_datum, buffer_length);
 734                 }
 735
 736                 return_ACPI_STATUS(status);
 737         }
 738
 739 /* TBD: Move to common setup code */
 740
 741         /* Field algorithm is limited to sizeof(u64), truncate if needed */
 742
 743         if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
 744                 obj_desc->common_field.access_byte_width = sizeof(u64);
 745                 access_bit_width = sizeof(u64) * 8;
 746         }
 747
 748         /* Compute the number of datums (access width data items) */
 749
 750         datum_count =
 751             ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
 752                              access_bit_width);
 753
 754         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
 755                                              obj_desc->common_field.
 756                                              start_field_bit_offset,
 757                                              access_bit_width);
 758
 759         /* Priming read from the field */
 760
 761         status =
 762             acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
 763                                    ACPI_READ);
 764         if (ACPI_FAILURE(status)) {
 765                 return_ACPI_STATUS(status);
 766         }
 767         merged_datum =
 768             raw_datum >> obj_desc->common_field.start_field_bit_offset;
 769
 770         /* Read the rest of the field */
 771
 772         for (i = 1; i < field_datum_count; i++) {
 773
 774                 /* Get next input datum from the field */
 775
 776                 field_offset += obj_desc->common_field.access_byte_width;
 777                 status = acpi_ex_field_datum_io(obj_desc, field_offset,
 778                                                 &raw_datum, ACPI_READ);
 779                 if (ACPI_FAILURE(status)) {
 780                         return_ACPI_STATUS(status);
 781                 }
 782
 783                 /*
 784                  * Merge with previous datum if necessary.
 785                  *
 786                  * Note: Before the shift, check if the shift value will be larger than
 787                  * the integer size. If so, there is no need to perform the operation.
 788                  * This avoids the differences in behavior between different compilers
 789                  * concerning shift values larger than the target data width.
 790                  */
 791                 if (access_bit_width -
 792                     obj_desc->common_field.start_field_bit_offset <
 793                     ACPI_INTEGER_BIT_SIZE) {
 794                         merged_datum |=
 795                             raw_datum << (access_bit_width -
 796                                           obj_desc->common_field.
 797                                           start_field_bit_offset);
 798                 }
 799
 800                 if (i == datum_count) {
 801                         break;
 802                 }
 803
 804                 /* Write merged datum to target buffer */
 805
 806                 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
 807                             ACPI_MIN(obj_desc->common_field.access_byte_width,
 808                                      buffer_length - buffer_offset));
 809
 810                 buffer_offset += obj_desc->common_field.access_byte_width;
 811                 merged_datum =
 812                     raw_datum >> obj_desc->common_field.start_field_bit_offset;
 813         }
 814
 815         /* Mask off any extra bits in the last datum */
 816
 817         buffer_tail_bits = obj_desc->common_field.bit_length % access_bit_width;
 818         if (buffer_tail_bits) {
 819                 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
 820         }
 821
 822         /* Write the last datum to the buffer */
 823
 824         ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
 825                     ACPI_MIN(obj_desc->common_field.access_byte_width,
 826                              buffer_length - buffer_offset));
 827
 828         return_ACPI_STATUS(AE_OK);
 829 }
 830
 831 /*******************************************************************************
 832  *
 833  * FUNCTION:    acpi_ex_insert_into_field
 834  *
 835  * PARAMETERS:  obj_desc            - Field to be written
 836  *              buffer              - Data to be written
 837  *              buffer_length       - Length of Buffer
 838  *
 839  * RETURN:      Status
 840  *
 841  * DESCRIPTION: Store the Buffer contents into the given field
 842  *
 843  ******************************************************************************/
 844
 845 acpi_status
 846 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
 847                           void *buffer, u32 buffer_length)
 848 {
 849         void *new_buffer;
 850         acpi_status status;
 851         u64 mask;
 852         u64 width_mask;
 853         u64 merged_datum;
 854         u64 raw_datum = 0;
 855         u32 field_offset = 0;
 856         u32 buffer_offset = 0;
 857         u32 buffer_tail_bits;
 858         u32 datum_count;
 859         u32 field_datum_count;
 860         u32 access_bit_width;
 861         u32 required_length;
 862         u32 i;
 863
 864         ACPI_FUNCTION_TRACE(ex_insert_into_field);
 865
 866         /* Validate input buffer */
 867
 868         new_buffer = NULL;
 869         required_length =
 870             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
 871         /*
 872          * We must have a buffer that is at least as long as the field
 873          * we are writing to. This is because individual fields are
 874          * indivisible and partial writes are not supported -- as per
 875          * the ACPI specification.
 876          */
 877         if (buffer_length < required_length) {
 878
 879                 /* We need to create a new buffer */
 880
 881                 new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
 882                 if (!new_buffer) {
 883                         return_ACPI_STATUS(AE_NO_MEMORY);
 884                 }
 885
 886                 /*
 887                  * Copy the original data to the new buffer, starting
 888                  * at Byte zero. All unused (upper) bytes of the
 889                  * buffer will be 0.
 890                  */
 891                 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length);
 892                 buffer = new_buffer;
 893                 buffer_length = required_length;
 894         }
 895
 896 /* TBD: Move to common setup code */
 897
 898         /* Algo is limited to sizeof(u64), so cut the access_byte_width */
 899         if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
 900                 obj_desc->common_field.access_byte_width = sizeof(u64);
 901         }
 902
 903         access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
 904
 905         /*
 906          * Create the bitmasks used for bit insertion.
 907          * Note: This if/else is used to bypass compiler differences with the
 908          * shift operator
 909          */
 910         if (access_bit_width == ACPI_INTEGER_BIT_SIZE) {
 911                 width_mask = ACPI_UINT64_MAX;
 912         } else {
 913                 width_mask = ACPI_MASK_BITS_ABOVE(access_bit_width);
 914         }
 915
 916         mask = width_mask &
 917             ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
 918
 919         /* Compute the number of datums (access width data items) */
 920
 921         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
 922                                        access_bit_width);
 923
 924         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
 925                                              obj_desc->common_field.
 926                                              start_field_bit_offset,
 927                                              access_bit_width);
 928
 929         /* Get initial Datum from the input buffer */
 930
 931         ACPI_MEMCPY(&raw_datum, buffer,
 932                     ACPI_MIN(obj_desc->common_field.access_byte_width,
 933                              buffer_length - buffer_offset));
 934
 935         merged_datum =
 936             raw_datum << obj_desc->common_field.start_field_bit_offset;
 937
 938         /* Write the entire field */
 939
 940         for (i = 1; i < field_datum_count; i++) {
 941
 942                 /* Write merged datum to the target field */
 943
 944                 merged_datum &= mask;
 945                 status = acpi_ex_write_with_update_rule(obj_desc, mask,
 946                                                         merged_datum,
 947                                                         field_offset);
 948                 if (ACPI_FAILURE(status)) {
 949                         goto exit;
 950                 }
 951
 952                 field_offset += obj_desc->common_field.access_byte_width;
 953
 954                 /*
 955                  * Start new output datum by merging with previous input datum
 956                  * if necessary.
 957                  *
 958                  * Note: Before the shift, check if the shift value will be larger than
 959                  * the integer size. If so, there is no need to perform the operation.
 960                  * This avoids the differences in behavior between different compilers
 961                  * concerning shift values larger than the target data width.
 962                  */
 963                 if ((access_bit_width -
 964                      obj_desc->common_field.start_field_bit_offset) <
 965                     ACPI_INTEGER_BIT_SIZE) {
 966                         merged_datum =
 967                             raw_datum >> (access_bit_width -
 968                                           obj_desc->common_field.
 969                                           start_field_bit_offset);
 970                 } else {
 971                         merged_datum = 0;
 972                 }
 973
 974                 mask = width_mask;
 975
 976                 if (i == datum_count) {
 977                         break;
 978                 }
 979
 980                 /* Get the next input datum from the buffer */
 981
 982                 buffer_offset += obj_desc->common_field.access_byte_width;
 983                 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset,
 984                             ACPI_MIN(obj_desc->common_field.access_byte_width,
 985                                      buffer_length - buffer_offset));
 986
 987                 merged_datum |=
 988                     raw_datum << obj_desc->common_field.start_field_bit_offset;
 989         }
 990
 991         /* Mask off any extra bits in the last datum */
 992
 993         buffer_tail_bits = (obj_desc->common_field.bit_length +
 994                             obj_desc->common_field.start_field_bit_offset) %
 995             access_bit_width;
 996         if (buffer_tail_bits) {
 997                 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
 998         }
 999
1000         /* Write the last datum to the field */
1001
1002         merged_datum &= mask;
1003         status = acpi_ex_write_with_update_rule(obj_desc,
1004                                                 mask, merged_datum,
1005                                                 field_offset);
1006
1007       exit:
1008         /* Free temporary buffer if we used one */
1009
1010         if (new_buffer) {
1011                 ACPI_FREE(new_buffer);
1012         }
1013         return_ACPI_STATUS(status);
1014 }