git.oblomov.eu Git - linux-2.6/blob - 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 (ACPI_GET_OBJECT_TYPE(rgn_desc) != ACPI_TYPE_REGION) {
  98                 ACPI_ERROR((AE_INFO, "Needed Region, found type %X (%s)",
  99                             ACPI_GET_OBJECT_TYPE(rgn_desc),
 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         acpi_physical_address address;
 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         address = rgn_desc->region.address +
 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                                                                      address)));
 270
 271         /* Invoke the appropriate address_space/op_region handler */
 272
 273         status = acpi_ev_address_space_dispatch(rgn_desc, function,
 274                                                 address,
 275                                                 ACPI_MUL_8(obj_desc->
 276                                                            common_field.
 277                                                            access_byte_width),
 278                                                 value);
 279
 280         if (ACPI_FAILURE(status)) {
 281                 if (status == AE_NOT_IMPLEMENTED) {
 282                         ACPI_ERROR((AE_INFO,
 283                                     "Region %s(%X) not implemented",
 284                                     acpi_ut_get_region_name(rgn_desc->region.
 285                                                             space_id),
 286                                     rgn_desc->region.space_id));
 287                 } else if (status == AE_NOT_EXIST) {
 288                         ACPI_ERROR((AE_INFO,
 289                                     "Region %s(%X) has no handler",
 290                                     acpi_ut_get_region_name(rgn_desc->region.
 291                                                             space_id),
 292                                     rgn_desc->region.space_id));
 293                 }
 294         }
 295
 296         return_ACPI_STATUS(status);
 297 }
 298
 299 /*******************************************************************************
 300  *
 301  * FUNCTION:    acpi_ex_register_overflow
 302  *
 303  * PARAMETERS:  obj_desc                - Register(Field) to be written
 304  *              Value                   - Value to be stored
 305  *
 306  * RETURN:      TRUE if value overflows the field, FALSE otherwise
 307  *
 308  * DESCRIPTION: Check if a value is out of range of the field being written.
 309  *              Used to check if the values written to Index and Bank registers
 310  *              are out of range.  Normally, the value is simply truncated
 311  *              to fit the field, but this case is most likely a serious
 312  *              coding error in the ASL.
 313  *
 314  ******************************************************************************/
 315
 316 static u8
 317 acpi_ex_register_overflow(union acpi_operand_object *obj_desc,
 318                           acpi_integer value)
 319 {
 320
 321         if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
 322                 /*
 323                  * The field is large enough to hold the maximum integer, so we can
 324                  * never overflow it.
 325                  */
 326                 return (FALSE);
 327         }
 328
 329         if (value >= ((acpi_integer) 1 << obj_desc->common_field.bit_length)) {
 330                 /*
 331                  * The Value is larger than the maximum value that can fit into
 332                  * the register.
 333                  */
 334                 return (TRUE);
 335         }
 336
 337         /* The Value will fit into the field with no truncation */
 338
 339         return (FALSE);
 340 }
 341
 342 /*******************************************************************************
 343  *
 344  * FUNCTION:    acpi_ex_field_datum_io
 345  *
 346  * PARAMETERS:  obj_desc                - Field to be read
 347  *              field_datum_byte_offset - Byte offset of this datum within the
 348  *                                        parent field
 349  *              Value                   - Where to store value (must be 64 bits)
 350  *              read_write              - Read or Write flag
 351  *
 352  * RETURN:      Status
 353  *
 354  * DESCRIPTION: Read or Write a single datum of a field.  The field_type is
 355  *              demultiplexed here to handle the different types of fields
 356  *              (buffer_field, region_field, index_field, bank_field)
 357  *
 358  ******************************************************************************/
 359
 360 static acpi_status
 361 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
 362                        u32 field_datum_byte_offset,
 363                        acpi_integer * value, u32 read_write)
 364 {
 365         acpi_status status;
 366         acpi_integer local_value;
 367
 368         ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
 369
 370         if (read_write == ACPI_READ) {
 371                 if (!value) {
 372                         local_value = 0;
 373
 374                         /* To support reads without saving return value */
 375                         value = &local_value;
 376                 }
 377
 378                 /* Clear the entire return buffer first, [Very Important!] */
 379
 380                 *value = 0;
 381         }
 382
 383         /*
 384          * The four types of fields are:
 385          *
 386          * buffer_field - Read/write from/to a Buffer
 387          * region_field - Read/write from/to a Operation Region.
 388          * bank_field  - Write to a Bank Register, then read/write from/to an
 389          *               operation_region
 390          * index_field - Write to an Index Register, then read/write from/to a
 391          *               Data Register
 392          */
 393         switch (ACPI_GET_OBJECT_TYPE(obj_desc)) {
 394         case ACPI_TYPE_BUFFER_FIELD:
 395                 /*
 396                  * If the buffer_field arguments have not been previously evaluated,
 397                  * evaluate them now and save the results.
 398                  */
 399                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 400                         status = acpi_ds_get_buffer_field_arguments(obj_desc);
 401                         if (ACPI_FAILURE(status)) {
 402                                 return_ACPI_STATUS(status);
 403                         }
 404                 }
 405
 406                 if (read_write == ACPI_READ) {
 407                         /*
 408                          * Copy the data from the source buffer.
 409                          * Length is the field width in bytes.
 410                          */
 411                         ACPI_MEMCPY(value,
 412                                     (obj_desc->buffer_field.buffer_obj)->buffer.
 413                                     pointer +
 414                                     obj_desc->buffer_field.base_byte_offset +
 415                                     field_datum_byte_offset,
 416                                     obj_desc->common_field.access_byte_width);
 417                 } else {
 418                         /*
 419                          * Copy the data to the target buffer.
 420                          * Length is the field width in bytes.
 421                          */
 422                         ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer.
 423                                     pointer +
 424                                     obj_desc->buffer_field.base_byte_offset +
 425                                     field_datum_byte_offset, value,
 426                                     obj_desc->common_field.access_byte_width);
 427                 }
 428
 429                 status = AE_OK;
 430                 break;
 431
 432         case ACPI_TYPE_LOCAL_BANK_FIELD:
 433
 434                 /*
 435                  * Ensure that the bank_value is not beyond the capacity of
 436                  * the register
 437                  */
 438                 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
 439                                               (acpi_integer) obj_desc->
 440                                               bank_field.value)) {
 441                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
 442                 }
 443
 444                 /*
 445                  * For bank_fields, we must write the bank_value to the bank_register
 446                  * (itself a region_field) before we can access the data.
 447                  */
 448                 status =
 449                     acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
 450                                               &obj_desc->bank_field.value,
 451                                               sizeof(obj_desc->bank_field.
 452                                                      value));
 453                 if (ACPI_FAILURE(status)) {
 454                         return_ACPI_STATUS(status);
 455                 }
 456
 457                 /*
 458                  * Now that the Bank has been selected, fall through to the
 459                  * region_field case and write the datum to the Operation Region
 460                  */
 461
 462                 /*lint -fallthrough */
 463
 464         case ACPI_TYPE_LOCAL_REGION_FIELD:
 465                 /*
 466                  * For simple region_fields, we just directly access the owning
 467                  * Operation Region.
 468                  */
 469                 status =
 470                     acpi_ex_access_region(obj_desc, field_datum_byte_offset,
 471                                           value, read_write);
 472                 break;
 473
 474         case ACPI_TYPE_LOCAL_INDEX_FIELD:
 475
 476                 /*
 477                  * Ensure that the index_value is not beyond the capacity of
 478                  * the register
 479                  */
 480                 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
 481                                               (acpi_integer) obj_desc->
 482                                               index_field.value)) {
 483                         return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
 484                 }
 485
 486                 /* Write the index value to the index_register (itself a region_field) */
 487
 488                 field_datum_byte_offset += obj_desc->index_field.value;
 489
 490                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 491                                   "Write to Index Register: Value %8.8X\n",
 492                                   field_datum_byte_offset));
 493
 494                 status =
 495                     acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
 496                                               &field_datum_byte_offset,
 497                                               sizeof(field_datum_byte_offset));
 498                 if (ACPI_FAILURE(status)) {
 499                         return_ACPI_STATUS(status);
 500                 }
 501
 502                 if (read_write == ACPI_READ) {
 503
 504                         /* Read the datum from the data_register */
 505
 506                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 507                                           "Read from Data Register\n"));
 508
 509                         status =
 510                             acpi_ex_extract_from_field(obj_desc->index_field.
 511                                                        data_obj, value,
 512                                                        sizeof(acpi_integer));
 513                 } else {
 514                         /* Write the datum to the data_register */
 515
 516                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 517                                           "Write to Data Register: Value %8.8X%8.8X\n",
 518                                           ACPI_FORMAT_UINT64(*value)));
 519
 520                         status =
 521                             acpi_ex_insert_into_field(obj_desc->index_field.
 522                                                       data_obj, value,
 523                                                       sizeof(acpi_integer));
 524                 }
 525                 break;
 526
 527         default:
 528
 529                 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %X",
 530                             ACPI_GET_OBJECT_TYPE(obj_desc)));
 531                 status = AE_AML_INTERNAL;
 532                 break;
 533         }
 534
 535         if (ACPI_SUCCESS(status)) {
 536                 if (read_write == ACPI_READ) {
 537                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 538                                           "Value Read %8.8X%8.8X, Width %d\n",
 539                                           ACPI_FORMAT_UINT64(*value),
 540                                           obj_desc->common_field.
 541                                           access_byte_width));
 542                 } else {
 543                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 544                                           "Value Written %8.8X%8.8X, Width %d\n",
 545                                           ACPI_FORMAT_UINT64(*value),
 546                                           obj_desc->common_field.
 547                                           access_byte_width));
 548                 }
 549         }
 550
 551         return_ACPI_STATUS(status);
 552 }
 553
 554 /*******************************************************************************
 555  *
 556  * FUNCTION:    acpi_ex_write_with_update_rule
 557  *
 558  * PARAMETERS:  obj_desc                - Field to be written
 559  *              Mask                    - bitmask within field datum
 560  *              field_value             - Value to write
 561  *              field_datum_byte_offset - Offset of datum within field
 562  *
 563  * RETURN:      Status
 564  *
 565  * DESCRIPTION: Apply the field update rule to a field write
 566  *
 567  ******************************************************************************/
 568
 569 acpi_status
 570 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc,
 571                                acpi_integer mask,
 572                                acpi_integer field_value,
 573                                u32 field_datum_byte_offset)
 574 {
 575         acpi_status status = AE_OK;
 576         acpi_integer merged_value;
 577         acpi_integer current_value;
 578
 579         ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask);
 580
 581         /* Start with the new bits  */
 582
 583         merged_value = field_value;
 584
 585         /* If the mask is all ones, we don't need to worry about the update rule */
 586
 587         if (mask != ACPI_INTEGER_MAX) {
 588
 589                 /* Decode the update rule */
 590
 591                 switch (obj_desc->common_field.
 592                         field_flags & AML_FIELD_UPDATE_RULE_MASK) {
 593                 case AML_FIELD_UPDATE_PRESERVE:
 594                         /*
 595                          * Check if update rule needs to be applied (not if mask is all
 596                          * ones)  The left shift drops the bits we want to ignore.
 597                          */
 598                         if ((~mask << (ACPI_MUL_8(sizeof(mask)) -
 599                                        ACPI_MUL_8(obj_desc->common_field.
 600                                                   access_byte_width))) != 0) {
 601                                 /*
 602                                  * Read the current contents of the byte/word/dword containing
 603                                  * the field, and merge with the new field value.
 604                                  */
 605                                 status =
 606                                     acpi_ex_field_datum_io(obj_desc,
 607                                                            field_datum_byte_offset,
 608                                                            &current_value,
 609                                                            ACPI_READ);
 610                                 if (ACPI_FAILURE(status)) {
 611                                         return_ACPI_STATUS(status);
 612                                 }
 613
 614                                 merged_value |= (current_value & ~mask);
 615                         }
 616                         break;
 617
 618                 case AML_FIELD_UPDATE_WRITE_AS_ONES:
 619
 620                         /* Set positions outside the field to all ones */
 621
 622                         merged_value |= ~mask;
 623                         break;
 624
 625                 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
 626
 627                         /* Set positions outside the field to all zeros */
 628
 629                         merged_value &= mask;
 630                         break;
 631
 632                 default:
 633
 634                         ACPI_ERROR((AE_INFO,
 635                                     "Unknown UpdateRule value: %X",
 636                                     (obj_desc->common_field.
 637                                      field_flags &
 638                                      AML_FIELD_UPDATE_RULE_MASK)));
 639                         return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
 640                 }
 641         }
 642
 643         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 644                           "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
 645                           ACPI_FORMAT_UINT64(mask),
 646                           field_datum_byte_offset,
 647                           obj_desc->common_field.access_byte_width,
 648                           ACPI_FORMAT_UINT64(field_value),
 649                           ACPI_FORMAT_UINT64(merged_value)));
 650
 651         /* Write the merged value */
 652
 653         status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset,
 654                                         &merged_value, ACPI_WRITE);
 655
 656         return_ACPI_STATUS(status);
 657 }
 658
 659 /*******************************************************************************
 660  *
 661  * FUNCTION:    acpi_ex_extract_from_field
 662  *
 663  * PARAMETERS:  obj_desc            - Field to be read
 664  *              Buffer              - Where to store the field data
 665  *              buffer_length       - Length of Buffer
 666  *
 667  * RETURN:      Status
 668  *
 669  * DESCRIPTION: Retrieve the current value of the given field
 670  *
 671  ******************************************************************************/
 672
 673 acpi_status
 674 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
 675                            void *buffer, u32 buffer_length)
 676 {
 677         acpi_status status;
 678         acpi_integer raw_datum;
 679         acpi_integer merged_datum;
 680         u32 field_offset = 0;
 681         u32 buffer_offset = 0;
 682         u32 buffer_tail_bits;
 683         u32 datum_count;
 684         u32 field_datum_count;
 685         u32 i;
 686
 687         ACPI_FUNCTION_TRACE(ex_extract_from_field);
 688
 689         /* Validate target buffer and clear it */
 690
 691         if (buffer_length <
 692             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
 693                 ACPI_ERROR((AE_INFO,
 694                             "Field size %X (bits) is too large for buffer (%X)",
 695                             obj_desc->common_field.bit_length, buffer_length));
 696
 697                 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
 698         }
 699         ACPI_MEMSET(buffer, 0, buffer_length);
 700
 701         /* Compute the number of datums (access width data items) */
 702
 703         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
 704                                        obj_desc->common_field.access_bit_width);
 705         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
 706                                              obj_desc->common_field.
 707                                              start_field_bit_offset,
 708                                              obj_desc->common_field.
 709                                              access_bit_width);
 710
 711         /* Priming read from the field */
 712
 713         status =
 714             acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
 715                                    ACPI_READ);
 716         if (ACPI_FAILURE(status)) {
 717                 return_ACPI_STATUS(status);
 718         }
 719         merged_datum =
 720             raw_datum >> obj_desc->common_field.start_field_bit_offset;
 721
 722         /* Read the rest of the field */
 723
 724         for (i = 1; i < field_datum_count; i++) {
 725
 726                 /* Get next input datum from the field */
 727
 728                 field_offset += obj_desc->common_field.access_byte_width;
 729                 status = acpi_ex_field_datum_io(obj_desc, field_offset,
 730                                                 &raw_datum, ACPI_READ);
 731                 if (ACPI_FAILURE(status)) {
 732                         return_ACPI_STATUS(status);
 733                 }
 734
 735                 /*
 736                  * Merge with previous datum if necessary.
 737                  *
 738                  * Note: Before the shift, check if the shift value will be larger than
 739                  * the integer size. If so, there is no need to perform the operation.
 740                  * This avoids the differences in behavior between different compilers
 741                  * concerning shift values larger than the target data width.
 742                  */
 743                 if ((obj_desc->common_field.access_bit_width -
 744                      obj_desc->common_field.start_field_bit_offset) <
 745                     ACPI_INTEGER_BIT_SIZE) {
 746                         merged_datum |=
 747                             raw_datum << (obj_desc->common_field.
 748                                           access_bit_width -
 749                                           obj_desc->common_field.
 750                                           start_field_bit_offset);
 751                 }
 752
 753                 if (i == datum_count) {
 754                         break;
 755                 }
 756
 757                 /* Write merged datum to target buffer */
 758
 759                 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
 760                             ACPI_MIN(obj_desc->common_field.access_byte_width,
 761                                      buffer_length - buffer_offset));
 762
 763                 buffer_offset += obj_desc->common_field.access_byte_width;
 764                 merged_datum =
 765                     raw_datum >> obj_desc->common_field.start_field_bit_offset;
 766         }
 767
 768         /* Mask off any extra bits in the last datum */
 769
 770         buffer_tail_bits = obj_desc->common_field.bit_length %
 771             obj_desc->common_field.access_bit_width;
 772         if (buffer_tail_bits) {
 773                 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
 774         }
 775
 776         /* Write the last datum to the buffer */
 777
 778         ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
 779                     ACPI_MIN(obj_desc->common_field.access_byte_width,
 780                              buffer_length - buffer_offset));
 781
 782         return_ACPI_STATUS(AE_OK);
 783 }
 784
 785 /*******************************************************************************
 786  *
 787  * FUNCTION:    acpi_ex_insert_into_field
 788  *
 789  * PARAMETERS:  obj_desc            - Field to be written
 790  *              Buffer              - Data to be written
 791  *              buffer_length       - Length of Buffer
 792  *
 793  * RETURN:      Status
 794  *
 795  * DESCRIPTION: Store the Buffer contents into the given field
 796  *
 797  ******************************************************************************/
 798
 799 acpi_status
 800 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
 801                           void *buffer, u32 buffer_length)
 802 {
 803         acpi_status status;
 804         acpi_integer mask;
 805         acpi_integer width_mask;
 806         acpi_integer merged_datum;
 807         acpi_integer raw_datum = 0;
 808         u32 field_offset = 0;
 809         u32 buffer_offset = 0;
 810         u32 buffer_tail_bits;
 811         u32 datum_count;
 812         u32 field_datum_count;
 813         u32 i;
 814         u32 required_length;
 815         void *new_buffer;
 816
 817         ACPI_FUNCTION_TRACE(ex_insert_into_field);
 818
 819         /* Validate input buffer */
 820
 821         new_buffer = NULL;
 822         required_length =
 823             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
 824         /*
 825          * We must have a buffer that is at least as long as the field
 826          * we are writing to.  This is because individual fields are
 827          * indivisible and partial writes are not supported -- as per
 828          * the ACPI specification.
 829          */
 830         if (buffer_length < required_length) {
 831
 832                 /* We need to create a new buffer */
 833
 834                 new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
 835                 if (!new_buffer) {
 836                         return_ACPI_STATUS(AE_NO_MEMORY);
 837                 }
 838
 839                 /*
 840                  * Copy the original data to the new buffer, starting
 841                  * at Byte zero.  All unused (upper) bytes of the
 842                  * buffer will be 0.
 843                  */
 844                 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length);
 845                 buffer = new_buffer;
 846                 buffer_length = required_length;
 847         }
 848
 849         /*
 850          * Create the bitmasks used for bit insertion.
 851          * Note: This if/else is used to bypass compiler differences with the
 852          * shift operator
 853          */
 854         if (obj_desc->common_field.access_bit_width == ACPI_INTEGER_BIT_SIZE) {
 855                 width_mask = ACPI_INTEGER_MAX;
 856         } else {
 857                 width_mask =
 858                     ACPI_MASK_BITS_ABOVE(obj_desc->common_field.
 859                                          access_bit_width);
 860         }
 861
 862         mask = width_mask &
 863             ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
 864
 865         /* Compute the number of datums (access width data items) */
 866
 867         datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
 868                                        obj_desc->common_field.access_bit_width);
 869
 870         field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
 871                                              obj_desc->common_field.
 872                                              start_field_bit_offset,
 873                                              obj_desc->common_field.
 874                                              access_bit_width);
 875
 876         /* Get initial Datum from the input buffer */
 877
 878         ACPI_MEMCPY(&raw_datum, buffer,
 879                     ACPI_MIN(obj_desc->common_field.access_byte_width,
 880                              buffer_length - buffer_offset));
 881
 882         merged_datum =
 883             raw_datum << obj_desc->common_field.start_field_bit_offset;
 884
 885         /* Write the entire field */
 886
 887         for (i = 1; i < field_datum_count; i++) {
 888
 889                 /* Write merged datum to the target field */
 890
 891                 merged_datum &= mask;
 892                 status = acpi_ex_write_with_update_rule(obj_desc, mask,
 893                                                         merged_datum,
 894                                                         field_offset);
 895                 if (ACPI_FAILURE(status)) {
 896                         goto exit;
 897                 }
 898
 899                 field_offset += obj_desc->common_field.access_byte_width;
 900
 901                 /*
 902                  * Start new output datum by merging with previous input datum
 903                  * if necessary.
 904                  *
 905                  * Note: Before the shift, check if the shift value will be larger than
 906                  * the integer size. If so, there is no need to perform the operation.
 907                  * This avoids the differences in behavior between different compilers
 908                  * concerning shift values larger than the target data width.
 909                  */
 910                 if ((obj_desc->common_field.access_bit_width -
 911                      obj_desc->common_field.start_field_bit_offset) <
 912                     ACPI_INTEGER_BIT_SIZE) {
 913                         merged_datum =
 914                             raw_datum >> (obj_desc->common_field.
 915                                           access_bit_width -
 916                                           obj_desc->common_field.
 917                                           start_field_bit_offset);
 918                 } else {
 919                         merged_datum = 0;
 920                 }
 921
 922                 mask = width_mask;
 923
 924                 if (i == datum_count) {
 925                         break;
 926                 }
 927
 928                 /* Get the next input datum from the buffer */
 929
 930                 buffer_offset += obj_desc->common_field.access_byte_width;
 931                 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset,
 932                             ACPI_MIN(obj_desc->common_field.access_byte_width,
 933                                      buffer_length - buffer_offset));
 934                 merged_datum |=
 935                     raw_datum << obj_desc->common_field.start_field_bit_offset;
 936         }
 937
 938         /* Mask off any extra bits in the last datum */
 939
 940         buffer_tail_bits = (obj_desc->common_field.bit_length +
 941                             obj_desc->common_field.start_field_bit_offset) %
 942             obj_desc->common_field.access_bit_width;
 943         if (buffer_tail_bits) {
 944                 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
 945         }
 946
 947         /* Write the last datum to the field */
 948
 949         merged_datum &= mask;
 950         status = acpi_ex_write_with_update_rule(obj_desc,
 951                                                 mask, merged_datum,
 952                                                 field_offset);
 953
 954       exit:
 955         /* Free temporary buffer if we used one */
 956
 957         if (new_buffer) {
 958                 ACPI_FREE(new_buffer);
 959         }
 960         return_ACPI_STATUS(status);
 961 }