drivers/acpi/acpica/exprep.c

   1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
   2 /******************************************************************************
   3  *
   4  * Module Name: exprep - ACPI AML field prep utilities
   5  *
   6  * Copyright (C) 2000 - 2019, Intel Corp.
   7  *
   8  *****************************************************************************/
   9
  10 #include <acpi/acpi.h>
  11 #include "accommon.h"
  12 #include "acinterp.h"
  13 #include "amlcode.h"
  14 #include "acnamesp.h"
  15 #include "acdispat.h"
  16
  17 #define _COMPONENT          ACPI_EXECUTER
  18 ACPI_MODULE_NAME("exprep")
  19
  20 /* Local prototypes */
  21 static u32
  22 acpi_ex_decode_field_access(union acpi_operand_object *obj_desc,
  23                             u8 field_flags, u32 * return_byte_alignment);
  24
  25 #ifdef ACPI_UNDER_DEVELOPMENT
  26
  27 static u32
  28 acpi_ex_generate_access(u32 field_bit_offset,
  29                         u32 field_bit_length, u32 region_length);
  30
  31 /*******************************************************************************
  32  *
  33  * FUNCTION:    acpi_ex_generate_access
  34  *
  35  * PARAMETERS:  field_bit_offset    - Start of field within parent region/buffer
  36  *              field_bit_length    - Length of field in bits
  37  *              region_length       - Length of parent in bytes
  38  *
  39  * RETURN:      Field granularity (8, 16, 32 or 64) and
  40  *              byte_alignment (1, 2, 3, or 4)
  41  *
  42  * DESCRIPTION: Generate an optimal access width for fields defined with the
  43  *              any_acc keyword.
  44  *
  45  * NOTE: Need to have the region_length in order to check for boundary
  46  *       conditions (end-of-region). However, the region_length is a deferred
  47  *       operation. Therefore, to complete this implementation, the generation
  48  *       of this access width must be deferred until the region length has
  49  *       been evaluated.
  50  *
  51  ******************************************************************************/
  52
  53 static u32
  54 acpi_ex_generate_access(u32 field_bit_offset,
  55                         u32 field_bit_length, u32 region_length)
  56 {
  57         u32 field_byte_length;
  58         u32 field_byte_offset;
  59         u32 field_byte_end_offset;
  60         u32 access_byte_width;
  61         u32 field_start_offset;
  62         u32 field_end_offset;
  63         u32 minimum_access_width = 0xFFFFFFFF;
  64         u32 minimum_accesses = 0xFFFFFFFF;
  65         u32 accesses;
  66
  67         ACPI_FUNCTION_TRACE(ex_generate_access);
  68
  69         /* Round Field start offset and length to "minimal" byte boundaries */
  70
  71         field_byte_offset = ACPI_DIV_8(ACPI_ROUND_DOWN(field_bit_offset, 8));
  72
  73         field_byte_end_offset =
  74             ACPI_DIV_8(ACPI_ROUND_UP(field_bit_length + field_bit_offset, 8));
  75
  76         field_byte_length = field_byte_end_offset - field_byte_offset;
  77
  78         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
  79                           "Bit length %u, Bit offset %u\n",
  80                           field_bit_length, field_bit_offset));
  81
  82         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
  83                           "Byte Length %u, Byte Offset %u, End Offset %u\n",
  84                           field_byte_length, field_byte_offset,
  85                           field_byte_end_offset));
  86
  87         /*
  88          * Iterative search for the maximum access width that is both aligned
  89          * and does not go beyond the end of the region
  90          *
  91          * Start at byte_acc and work upwards to qword_acc max. (1,2,4,8 bytes)
  92          */
  93         for (access_byte_width = 1; access_byte_width <= 8;
  94              access_byte_width <<= 1) {
  95                 /*
  96                  * 1) Round end offset up to next access boundary and make sure that
  97                  *    this does not go beyond the end of the parent region.
  98                  * 2) When the Access width is greater than the field_byte_length, we
  99                  *    are done. (This does not optimize for the perfectly aligned
 100                  *    case yet).
 101                  */
 102                 if (ACPI_ROUND_UP(field_byte_end_offset, access_byte_width) <=
 103                     region_length) {
 104                         field_start_offset =
 105                             ACPI_ROUND_DOWN(field_byte_offset,
 106                                             access_byte_width) /
 107                             access_byte_width;
 108
 109                         field_end_offset =
 110                             ACPI_ROUND_UP((field_byte_length +
 111                                            field_byte_offset),
 112                                           access_byte_width) /
 113                             access_byte_width;
 114
 115                         accesses = field_end_offset - field_start_offset;
 116
 117                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 118                                           "AccessWidth %u end is within region\n",
 119                                           access_byte_width));
 120
 121                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 122                                           "Field Start %u, Field End %u -- requires %u accesses\n",
 123                                           field_start_offset, field_end_offset,
 124                                           accesses));
 125
 126                         /* Single access is optimal */
 127
 128                         if (accesses <= 1) {
 129                                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 130                                                   "Entire field can be accessed "
 131                                                   "with one operation of size %u\n",
 132                                                   access_byte_width));
 133                                 return_VALUE(access_byte_width);
 134                         }
 135
 136                         /*
 137                          * Fits in the region, but requires more than one read/write.
 138                          * try the next wider access on next iteration
 139                          */
 140                         if (accesses < minimum_accesses) {
 141                                 minimum_accesses = accesses;
 142                                 minimum_access_width = access_byte_width;
 143                         }
 144                 } else {
 145                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 146                                           "AccessWidth %u end is NOT within region\n",
 147                                           access_byte_width));
 148                         if (access_byte_width == 1) {
 149                                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 150                                                   "Field goes beyond end-of-region!\n"));
 151
 152                                 /* Field does not fit in the region at all */
 153
 154                                 return_VALUE(0);
 155                         }
 156
 157                         /*
 158                          * This width goes beyond the end-of-region, back off to
 159                          * previous access
 160                          */
 161                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 162                                           "Backing off to previous optimal access width of %u\n",
 163                                           minimum_access_width));
 164                         return_VALUE(minimum_access_width);
 165                 }
 166         }
 167
 168         /*
 169          * Could not read/write field with one operation,
 170          * just use max access width
 171          */
 172         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 173                           "Cannot access field in one operation, using width 8\n"));
 174
 175         return_VALUE(8);
 176 }
 177 #endif                          /* ACPI_UNDER_DEVELOPMENT */
 178
 179 /*******************************************************************************
 180  *
 181  * FUNCTION:    acpi_ex_decode_field_access
 182  *
 183  * PARAMETERS:  obj_desc            - Field object
 184  *              field_flags         - Encoded fieldflags (contains access bits)
 185  *              return_byte_alignment - Where the byte alignment is returned
 186  *
 187  * RETURN:      Field granularity (8, 16, 32 or 64) and
 188  *              byte_alignment (1, 2, 3, or 4)
 189  *
 190  * DESCRIPTION: Decode the access_type bits of a field definition.
 191  *
 192  ******************************************************************************/
 193
 194 static u32
 195 acpi_ex_decode_field_access(union acpi_operand_object *obj_desc,
 196                             u8 field_flags, u32 * return_byte_alignment)
 197 {
 198         u32 access;
 199         u32 byte_alignment;
 200         u32 bit_length;
 201
 202         ACPI_FUNCTION_TRACE(ex_decode_field_access);
 203
 204         access = (field_flags & AML_FIELD_ACCESS_TYPE_MASK);
 205
 206         switch (access) {
 207         case AML_FIELD_ACCESS_ANY:
 208
 209 #ifdef ACPI_UNDER_DEVELOPMENT
 210                 byte_alignment =
 211                     acpi_ex_generate_access(obj_desc->common_field.
 212                                             start_field_bit_offset,
 213                                             obj_desc->common_field.bit_length,
 214                                             0xFFFFFFFF
 215                                             /* Temp until we pass region_length as parameter */
 216                     );
 217                 bit_length = byte_alignment * 8;
 218 #endif
 219
 220                 byte_alignment = 1;
 221                 bit_length = 8;
 222                 break;
 223
 224         case AML_FIELD_ACCESS_BYTE:
 225         case AML_FIELD_ACCESS_BUFFER:   /* ACPI 2.0 (SMBus Buffer) */
 226
 227                 byte_alignment = 1;
 228                 bit_length = 8;
 229                 break;
 230
 231         case AML_FIELD_ACCESS_WORD:
 232
 233                 byte_alignment = 2;
 234                 bit_length = 16;
 235                 break;
 236
 237         case AML_FIELD_ACCESS_DWORD:
 238
 239                 byte_alignment = 4;
 240                 bit_length = 32;
 241                 break;
 242
 243         case AML_FIELD_ACCESS_QWORD:    /* ACPI 2.0 */
 244
 245                 byte_alignment = 8;
 246                 bit_length = 64;
 247                 break;
 248
 249         default:
 250
 251                 /* Invalid field access type */
 252
 253                 ACPI_ERROR((AE_INFO, "Unknown field access type 0x%X", access));
 254
 255                 return_UINT32(0);
 256         }
 257
 258         if (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD) {
 259                 /*
 260                  * buffer_field access can be on any byte boundary, so the
 261                  * byte_alignment is always 1 byte -- regardless of any byte_alignment
 262                  * implied by the field access type.
 263                  */
 264                 byte_alignment = 1;
 265         }
 266
 267         *return_byte_alignment = byte_alignment;
 268         return_UINT32(bit_length);
 269 }
 270
 271 /*******************************************************************************
 272  *
 273  * FUNCTION:    acpi_ex_prep_common_field_object
 274  *
 275  * PARAMETERS:  obj_desc            - The field object
 276  *              field_flags         - Access, lock_rule, and update_rule.
 277  *                                    The format of a field_flag is described
 278  *                                    in the ACPI specification
 279  *              field_attribute     - Special attributes (not used)
 280  *              field_bit_position  - Field start position
 281  *              field_bit_length    - Field length in number of bits
 282  *
 283  * RETURN:      Status
 284  *
 285  * DESCRIPTION: Initialize the areas of the field object that are common
 286  *              to the various types of fields. Note: This is very "sensitive"
 287  *              code because we are solving the general case for field
 288  *              alignment.
 289  *
 290  ******************************************************************************/
 291
 292 acpi_status
 293 acpi_ex_prep_common_field_object(union acpi_operand_object *obj_desc,
 294                                  u8 field_flags,
 295                                  u8 field_attribute,
 296                                  u32 field_bit_position, u32 field_bit_length)
 297 {
 298         u32 access_bit_width;
 299         u32 byte_alignment;
 300         u32 nearest_byte_address;
 301
 302         ACPI_FUNCTION_TRACE(ex_prep_common_field_object);
 303
 304         /*
 305          * Note: the structure being initialized is the
 306          * ACPI_COMMON_FIELD_INFO;  No structure fields outside of the common
 307          * area are initialized by this procedure.
 308          */
 309         obj_desc->common_field.field_flags = field_flags;
 310         obj_desc->common_field.attribute = field_attribute;
 311         obj_desc->common_field.bit_length = field_bit_length;
 312
 313         /*
 314          * Decode the access type so we can compute offsets. The access type gives
 315          * two pieces of information - the width of each field access and the
 316          * necessary byte_alignment (address granularity) of the access.
 317          *
 318          * For any_acc, the access_bit_width is the largest width that is both
 319          * necessary and possible in an attempt to access the whole field in one
 320          * I/O operation. However, for any_acc, the byte_alignment is always one
 321          * byte.
 322          *
 323          * For all Buffer Fields, the byte_alignment is always one byte.
 324          *
 325          * For all other access types (Byte, Word, Dword, Qword), the Bitwidth is
 326          * the same (equivalent) as the byte_alignment.
 327          */
 328         access_bit_width =
 329             acpi_ex_decode_field_access(obj_desc, field_flags, &byte_alignment);
 330         if (!access_bit_width) {
 331                 return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
 332         }
 333
 334         /* Setup width (access granularity) fields (values are: 1, 2, 4, 8) */
 335
 336         obj_desc->common_field.access_byte_width = (u8)
 337             ACPI_DIV_8(access_bit_width);
 338
 339         /*
 340          * base_byte_offset is the address of the start of the field within the
 341          * region. It is the byte address of the first *datum* (field-width data
 342          * unit) of the field. (i.e., the first datum that contains at least the
 343          * first *bit* of the field.)
 344          *
 345          * Note: byte_alignment is always either equal to the access_bit_width or 8
 346          * (Byte access), and it defines the addressing granularity of the parent
 347          * region or buffer.
 348          */
 349         nearest_byte_address =
 350             ACPI_ROUND_BITS_DOWN_TO_BYTES(field_bit_position);
 351         obj_desc->common_field.base_byte_offset = (u32)
 352             ACPI_ROUND_DOWN(nearest_byte_address, byte_alignment);
 353
 354         /*
 355          * start_field_bit_offset is the offset of the first bit of the field within
 356          * a field datum.
 357          */
 358         obj_desc->common_field.start_field_bit_offset = (u8)
 359             (field_bit_position -
 360              ACPI_MUL_8(obj_desc->common_field.base_byte_offset));
 361
 362         return_ACPI_STATUS(AE_OK);
 363 }
 364
 365 /*******************************************************************************
 366  *
 367  * FUNCTION:    acpi_ex_prep_field_value
 368  *
 369  * PARAMETERS:  info    - Contains all field creation info
 370  *
 371  * RETURN:      Status
 372  *
 373  * DESCRIPTION: Construct an object of type union acpi_operand_object with a
 374  *              subtype of def_field and connect it to the parent Node.
 375  *
 376  ******************************************************************************/
 377
 378 acpi_status acpi_ex_prep_field_value(struct acpi_create_field_info *info)
 379 {
 380         union acpi_operand_object *obj_desc;
 381         union acpi_operand_object *second_desc = NULL;
 382         acpi_status status;
 383         u32 access_byte_width;
 384         u32 type;
 385
 386         ACPI_FUNCTION_TRACE(ex_prep_field_value);
 387
 388         /* Parameter validation */
 389
 390         if (info->field_type != ACPI_TYPE_LOCAL_INDEX_FIELD) {
 391                 if (!info->region_node) {
 392                         ACPI_ERROR((AE_INFO, "Null RegionNode"));
 393                         return_ACPI_STATUS(AE_AML_NO_OPERAND);
 394                 }
 395
 396                 type = acpi_ns_get_type(info->region_node);
 397                 if (type != ACPI_TYPE_REGION) {
 398                         ACPI_ERROR((AE_INFO,
 399                                     "Needed Region, found type 0x%X (%s)", type,
 400                                     acpi_ut_get_type_name(type)));
 401
 402                         return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
 403                 }
 404         }
 405
 406         /* Allocate a new field object */
 407
 408         obj_desc = acpi_ut_create_internal_object(info->field_type);
 409         if (!obj_desc) {
 410                 return_ACPI_STATUS(AE_NO_MEMORY);
 411         }
 412
 413         /* Initialize areas of the object that are common to all fields */
 414
 415         obj_desc->common_field.node = info->field_node;
 416         status = acpi_ex_prep_common_field_object(obj_desc,
 417                                                   info->field_flags,
 418                                                   info->attribute,
 419                                                   info->field_bit_position,
 420                                                   info->field_bit_length);
 421         if (ACPI_FAILURE(status)) {
 422                 acpi_ut_delete_object_desc(obj_desc);
 423                 return_ACPI_STATUS(status);
 424         }
 425
 426         /* Initialize areas of the object that are specific to the field type */
 427
 428         switch (info->field_type) {
 429         case ACPI_TYPE_LOCAL_REGION_FIELD:
 430
 431                 obj_desc->field.region_obj =
 432                     acpi_ns_get_attached_object(info->region_node);
 433
 434                 /* Fields specific to generic_serial_bus fields */
 435
 436                 obj_desc->field.access_length = info->access_length;
 437
 438                 if (info->connection_node) {
 439                         second_desc = info->connection_node->object;
 440                         if (!(second_desc->common.flags & AOPOBJ_DATA_VALID)) {
 441                                 status =
 442                                     acpi_ds_get_buffer_arguments(second_desc);
 443                                 if (ACPI_FAILURE(status)) {
 444                                         acpi_ut_delete_object_desc(obj_desc);
 445                                         return_ACPI_STATUS(status);
 446                                 }
 447                         }
 448
 449                         obj_desc->field.resource_buffer =
 450                             second_desc->buffer.pointer;
 451                         obj_desc->field.resource_length =
 452                             (u16)second_desc->buffer.length;
 453                 } else if (info->resource_buffer) {
 454                         obj_desc->field.resource_buffer = info->resource_buffer;
 455                         obj_desc->field.resource_length = info->resource_length;
 456                 }
 457
 458                 obj_desc->field.pin_number_index = info->pin_number_index;
 459
 460                 /* Allow full data read from EC address space */
 461
 462                 if ((obj_desc->field.region_obj->region.space_id ==
 463                      ACPI_ADR_SPACE_EC)
 464                     && (obj_desc->common_field.bit_length > 8)) {
 465                         access_byte_width =
 466                             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.
 467                                                         bit_length);
 468
 469                         /* Maximum byte width supported is 255 */
 470
 471                         if (access_byte_width < 256) {
 472                                 obj_desc->common_field.access_byte_width =
 473                                     (u8)access_byte_width;
 474                         }
 475                 }
 476                 /* An additional reference for the container */
 477
 478                 acpi_ut_add_reference(obj_desc->field.region_obj);
 479
 480                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 481                                   "RegionField: BitOff %X, Off %X, Gran %X, Region %p\n",
 482                                   obj_desc->field.start_field_bit_offset,
 483                                   obj_desc->field.base_byte_offset,
 484                                   obj_desc->field.access_byte_width,
 485                                   obj_desc->field.region_obj));
 486                 break;
 487
 488         case ACPI_TYPE_LOCAL_BANK_FIELD:
 489
 490                 obj_desc->bank_field.value = info->bank_value;
 491                 obj_desc->bank_field.region_obj =
 492                     acpi_ns_get_attached_object(info->region_node);
 493                 obj_desc->bank_field.bank_obj =
 494                     acpi_ns_get_attached_object(info->register_node);
 495
 496                 /* An additional reference for the attached objects */
 497
 498                 acpi_ut_add_reference(obj_desc->bank_field.region_obj);
 499                 acpi_ut_add_reference(obj_desc->bank_field.bank_obj);
 500
 501                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 502                                   "Bank Field: BitOff %X, Off %X, Gran %X, Region %p, BankReg %p\n",
 503                                   obj_desc->bank_field.start_field_bit_offset,
 504                                   obj_desc->bank_field.base_byte_offset,
 505                                   obj_desc->field.access_byte_width,
 506                                   obj_desc->bank_field.region_obj,
 507                                   obj_desc->bank_field.bank_obj));
 508
 509                 /*
 510                  * Remember location in AML stream of the field unit
 511                  * opcode and operands -- since the bank_value
 512                  * operands must be evaluated.
 513                  */
 514                 second_desc = obj_desc->common.next_object;
 515                 second_desc->extra.aml_start =
 516                     ACPI_CAST_PTR(union acpi_parse_object,
 517                                   info->data_register_node)->named.data;
 518                 second_desc->extra.aml_length =
 519                     ACPI_CAST_PTR(union acpi_parse_object,
 520                                   info->data_register_node)->named.length;
 521
 522                 break;
 523
 524         case ACPI_TYPE_LOCAL_INDEX_FIELD:
 525
 526                 /* Get the Index and Data registers */
 527
 528                 obj_desc->index_field.index_obj =
 529                     acpi_ns_get_attached_object(info->register_node);
 530                 obj_desc->index_field.data_obj =
 531                     acpi_ns_get_attached_object(info->data_register_node);
 532
 533                 if (!obj_desc->index_field.data_obj
 534                     || !obj_desc->index_field.index_obj) {
 535                         ACPI_ERROR((AE_INFO,
 536                                     "Null Index Object during field prep"));
 537                         acpi_ut_delete_object_desc(obj_desc);
 538                         return_ACPI_STATUS(AE_AML_INTERNAL);
 539                 }
 540
 541                 /* An additional reference for the attached objects */
 542
 543                 acpi_ut_add_reference(obj_desc->index_field.data_obj);
 544                 acpi_ut_add_reference(obj_desc->index_field.index_obj);
 545
 546                 /*
 547                  * April 2006: Changed to match MS behavior
 548                  *
 549                  * The value written to the Index register is the byte offset of the
 550                  * target field in units of the granularity of the index_field
 551                  *
 552                  * Previously, the value was calculated as an index in terms of the
 553                  * width of the Data register, as below:
 554                  *
 555                  *      obj_desc->index_field.Value = (u32)
 556                  *          (Info->field_bit_position / ACPI_MUL_8 (
 557                  *              obj_desc->Field.access_byte_width));
 558                  *
 559                  * February 2006: Tried value as a byte offset:
 560                  *      obj_desc->index_field.Value = (u32)
 561                  *          ACPI_DIV_8 (Info->field_bit_position);
 562                  */
 563                 obj_desc->index_field.value =
 564                     (u32) ACPI_ROUND_DOWN(ACPI_DIV_8(info->field_bit_position),
 565                                           obj_desc->index_field.
 566                                           access_byte_width);
 567
 568                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 569                                   "IndexField: BitOff %X, Off %X, Value %X, "
 570                                   "Gran %X, Index %p, Data %p\n",
 571                                   obj_desc->index_field.start_field_bit_offset,
 572                                   obj_desc->index_field.base_byte_offset,
 573                                   obj_desc->index_field.value,
 574                                   obj_desc->field.access_byte_width,
 575                                   obj_desc->index_field.index_obj,
 576                                   obj_desc->index_field.data_obj));
 577                 break;
 578
 579         default:
 580
 581                 /* No other types should get here */
 582
 583                 break;
 584         }
 585
 586         /*
 587          * Store the constructed descriptor (obj_desc) into the parent Node,
 588          * preserving the current type of that named_obj.
 589          */
 590         status =
 591             acpi_ns_attach_object(info->field_node, obj_desc,
 592                                   acpi_ns_get_type(info->field_node));
 593
 594         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 595                           "Set NamedObj %p [%4.4s], ObjDesc %p\n",
 596                           info->field_node,
 597                           acpi_ut_get_node_name(info->field_node), obj_desc));
 598
 599         /* Remove local reference to the object */
 600
 601         acpi_ut_remove_reference(obj_desc);
 602         return_ACPI_STATUS(status);
 603 }