git.oblomov.eu Git - linux-2.6/blob - drivers/acpi/executer/exprep.c

   1
   2 /******************************************************************************
   3  *
   4  * Module Name: exprep - ACPI AML (p-code) execution - field prep utilities
   5  *
   6  *****************************************************************************/
   7
   8 /*
   9  * Copyright (C) 2000 - 2005, R. Byron Moore
  10  * All rights reserved.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions, and the following disclaimer,
  17  *    without modification.
  18  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  19  *    substantially similar to the "NO WARRANTY" disclaimer below
  20  *    ("Disclaimer") and any redistribution must be conditioned upon
  21  *    including a substantially similar Disclaimer requirement for further
  22  *    binary redistribution.
  23  * 3. Neither the names of the above-listed copyright holders nor the names
  24  *    of any contributors may be used to endorse or promote products derived
  25  *    from this software without specific prior written permission.
  26  *
  27  * Alternatively, this software may be distributed under the terms of the
  28  * GNU General Public License ("GPL") version 2 as published by the Free
  29  * Software Foundation.
  30  *
  31  * NO WARRANTY
  32  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  33  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  34  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  35  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  36  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  40  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  41  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  42  * POSSIBILITY OF SUCH DAMAGES.
  43  */
  44
  45
  46 #include <acpi/acpi.h>
  47 #include <acpi/acinterp.h>
  48 #include <acpi/amlcode.h>
  49 #include <acpi/acnamesp.h>
  50
  51
  52 #define _COMPONENT          ACPI_EXECUTER
  53          ACPI_MODULE_NAME    ("exprep")
  54
  55 /* Local prototypes */
  56
  57 static u32
  58 acpi_ex_decode_field_access (
  59         union acpi_operand_object       *obj_desc,
  60         u8                              field_flags,
  61         u32                             *return_byte_alignment);
  62
  63
  64 #ifdef ACPI_UNDER_DEVELOPMENT
  65
  66 static u32
  67 acpi_ex_generate_access (
  68         u32                             field_bit_offset,
  69         u32                             field_bit_length,
  70         u32                             region_length);
  71
  72 /*******************************************************************************
  73  *
  74  * FUNCTION:    acpi_ex_generate_access
  75  *
  76  * PARAMETERS:  field_bit_offset    - Start of field within parent region/buffer
  77  *              field_bit_length    - Length of field in bits
  78  *              region_length       - Length of parent in bytes
  79  *
  80  * RETURN:      Field granularity (8, 16, 32 or 64) and
  81  *              byte_alignment (1, 2, 3, or 4)
  82  *
  83  * DESCRIPTION: Generate an optimal access width for fields defined with the
  84  *              any_acc keyword.
  85  *
  86  * NOTE: Need to have the region_length in order to check for boundary
  87  *       conditions (end-of-region).  However, the region_length is a deferred
  88  *       operation.  Therefore, to complete this implementation, the generation
  89  *       of this access width must be deferred until the region length has
  90  *       been evaluated.
  91  *
  92  ******************************************************************************/
  93
  94 static u32
  95 acpi_ex_generate_access (
  96         u32                             field_bit_offset,
  97         u32                             field_bit_length,
  98         u32                             region_length)
  99 {
 100         u32                             field_byte_length;
 101         u32                             field_byte_offset;
 102         u32                             field_byte_end_offset;
 103         u32                             access_byte_width;
 104         u32                             field_start_offset;
 105         u32                             field_end_offset;
 106         u32                             minimum_access_width = 0xFFFFFFFF;
 107         u32                             minimum_accesses = 0xFFFFFFFF;
 108         u32                             accesses;
 109
 110
 111         ACPI_FUNCTION_TRACE ("ex_generate_access");
 112
 113
 114         /* Round Field start offset and length to "minimal" byte boundaries */
 115
 116         field_byte_offset  = ACPI_DIV_8 (ACPI_ROUND_DOWN (field_bit_offset, 8));
 117         field_byte_end_offset = ACPI_DIV_8 (ACPI_ROUND_UP (field_bit_length +
 118                            field_bit_offset, 8));
 119         field_byte_length  = field_byte_end_offset - field_byte_offset;
 120
 121         ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
 122                         "Bit length %d, Bit offset %d\n",
 123                         field_bit_length, field_bit_offset));
 124
 125         ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
 126                         "Byte Length %d, Byte Offset %d, End Offset %d\n",
 127                         field_byte_length, field_byte_offset, field_byte_end_offset));
 128
 129         /*
 130          * Iterative search for the maximum access width that is both aligned
 131          * and does not go beyond the end of the region
 132          *
 133          * Start at byte_acc and work upwards to qword_acc max. (1,2,4,8 bytes)
 134          */
 135         for (access_byte_width = 1; access_byte_width <= 8; access_byte_width <<= 1) {
 136                 /*
 137                  * 1) Round end offset up to next access boundary and make sure that
 138                  *    this does not go beyond the end of the parent region.
 139                  * 2) When the Access width is greater than the field_byte_length, we
 140                  *    are done. (This does not optimize for the perfectly aligned
 141                  *    case yet).
 142                  */
 143                 if (ACPI_ROUND_UP (field_byte_end_offset, access_byte_width) <= region_length) {
 144                         field_start_offset =
 145                                 ACPI_ROUND_DOWN (field_byte_offset, access_byte_width) /
 146                                 access_byte_width;
 147
 148                         field_end_offset =
 149                                 ACPI_ROUND_UP ((field_byte_length + field_byte_offset),
 150                                         access_byte_width) / access_byte_width;
 151
 152                         accesses = field_end_offset - field_start_offset;
 153
 154                         ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
 155                                         "access_width %d end is within region\n", access_byte_width));
 156
 157                         ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
 158                                         "Field Start %d, Field End %d -- requires %d accesses\n",
 159                                         field_start_offset, field_end_offset, accesses));
 160
 161                         /* Single access is optimal */
 162
 163                         if (accesses <= 1) {
 164                                 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
 165                                         "Entire field can be accessed with one operation of size %d\n",
 166                                         access_byte_width));
 167                                 return_VALUE (access_byte_width);
 168                         }
 169
 170                         /*
 171                          * Fits in the region, but requires more than one read/write.
 172                          * try the next wider access on next iteration
 173                          */
 174                         if (accesses < minimum_accesses) {
 175                                 minimum_accesses   = accesses;
 176                                 minimum_access_width = access_byte_width;
 177                         }
 178                 }
 179                 else {
 180                         ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
 181                                 "access_width %d end is NOT within region\n", access_byte_width));
 182                         if (access_byte_width == 1) {
 183                                 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
 184                                                 "Field goes beyond end-of-region!\n"));
 185
 186                                 /* Field does not fit in the region at all */
 187
 188                                 return_VALUE (0);
 189                         }
 190
 191                         /*
 192                          * This width goes beyond the end-of-region, back off to
 193                          * previous access
 194                          */
 195                         ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
 196                                         "Backing off to previous optimal access width of %d\n",
 197                                         minimum_access_width));
 198                         return_VALUE (minimum_access_width);
 199                 }
 200         }
 201
 202         /*
 203          * Could not read/write field with one operation,
 204          * just use max access width
 205          */
 206         ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
 207                         "Cannot access field in one operation, using width 8\n"));
 208         return_VALUE (8);
 209 }
 210 #endif /* ACPI_UNDER_DEVELOPMENT */
 211
 212
 213 /*******************************************************************************
 214  *
 215  * FUNCTION:    acpi_ex_decode_field_access
 216  *
 217  * PARAMETERS:  obj_desc            - Field object
 218  *              field_flags         - Encoded fieldflags (contains access bits)
 219  *              return_byte_alignment - Where the byte alignment is returned
 220  *
 221  * RETURN:      Field granularity (8, 16, 32 or 64) and
 222  *              byte_alignment (1, 2, 3, or 4)
 223  *
 224  * DESCRIPTION: Decode the access_type bits of a field definition.
 225  *
 226  ******************************************************************************/
 227
 228 static u32
 229 acpi_ex_decode_field_access (
 230         union acpi_operand_object       *obj_desc,
 231         u8                              field_flags,
 232         u32                             *return_byte_alignment)
 233 {
 234         u32                             access;
 235         u32                             byte_alignment;
 236         u32                             bit_length;
 237
 238
 239         ACPI_FUNCTION_TRACE ("ex_decode_field_access");
 240
 241
 242         access = (field_flags & AML_FIELD_ACCESS_TYPE_MASK);
 243
 244         switch (access) {
 245         case AML_FIELD_ACCESS_ANY:
 246
 247 #ifdef ACPI_UNDER_DEVELOPMENT
 248                 byte_alignment =
 249                         acpi_ex_generate_access (obj_desc->common_field.start_field_bit_offset,
 250                                 obj_desc->common_field.bit_length,
 251                                 0xFFFFFFFF /* Temp until we pass region_length as parameter */);
 252                 bit_length = byte_alignment * 8;
 253 #endif
 254
 255                 byte_alignment = 1;
 256                 bit_length = 8;
 257                 break;
 258
 259         case AML_FIELD_ACCESS_BYTE:
 260         case AML_FIELD_ACCESS_BUFFER:   /* ACPI 2.0 (SMBus Buffer) */
 261                 byte_alignment = 1;
 262                 bit_length    = 8;
 263                 break;
 264
 265         case AML_FIELD_ACCESS_WORD:
 266                 byte_alignment = 2;
 267                 bit_length    = 16;
 268                 break;
 269
 270         case AML_FIELD_ACCESS_DWORD:
 271                 byte_alignment = 4;
 272                 bit_length    = 32;
 273                 break;
 274
 275         case AML_FIELD_ACCESS_QWORD:    /* ACPI 2.0 */
 276                 byte_alignment = 8;
 277                 bit_length    = 64;
 278                 break;
 279
 280         default:
 281                 /* Invalid field access type */
 282
 283                 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
 284                         "Unknown field access type %X\n",
 285                         access));
 286                 return_VALUE (0);
 287         }
 288
 289         if (ACPI_GET_OBJECT_TYPE (obj_desc) == ACPI_TYPE_BUFFER_FIELD) {
 290                 /*
 291                  * buffer_field access can be on any byte boundary, so the
 292                  * byte_alignment is always 1 byte -- regardless of any byte_alignment
 293                  * implied by the field access type.
 294                  */
 295                 byte_alignment = 1;
 296         }
 297
 298         *return_byte_alignment = byte_alignment;
 299         return_VALUE (bit_length);
 300 }
 301
 302
 303 /*******************************************************************************
 304  *
 305  * FUNCTION:    acpi_ex_prep_common_field_object
 306  *
 307  * PARAMETERS:  obj_desc            - The field object
 308  *              field_flags         - Access, lock_rule, and update_rule.
 309  *                                    The format of a field_flag is described
 310  *                                    in the ACPI specification
 311  *              field_attribute     - Special attributes (not used)
 312  *              field_bit_position  - Field start position
 313  *              field_bit_length    - Field length in number of bits
 314  *
 315  * RETURN:      Status
 316  *
 317  * DESCRIPTION: Initialize the areas of the field object that are common
 318  *              to the various types of fields.  Note: This is very "sensitive"
 319  *              code because we are solving the general case for field
 320  *              alignment.
 321  *
 322  ******************************************************************************/
 323
 324 acpi_status
 325 acpi_ex_prep_common_field_object (
 326         union acpi_operand_object       *obj_desc,
 327         u8                              field_flags,
 328         u8                              field_attribute,
 329         u32                             field_bit_position,
 330         u32                             field_bit_length)
 331 {
 332         u32                             access_bit_width;
 333         u32                             byte_alignment;
 334         u32                             nearest_byte_address;
 335
 336
 337         ACPI_FUNCTION_TRACE ("ex_prep_common_field_object");
 338
 339
 340         /*
 341          * Note: the structure being initialized is the
 342          * ACPI_COMMON_FIELD_INFO;  No structure fields outside of the common
 343          * area are initialized by this procedure.
 344          */
 345         obj_desc->common_field.field_flags = field_flags;
 346         obj_desc->common_field.attribute = field_attribute;
 347         obj_desc->common_field.bit_length = field_bit_length;
 348
 349         /*
 350          * Decode the access type so we can compute offsets.  The access type gives
 351          * two pieces of information - the width of each field access and the
 352          * necessary byte_alignment (address granularity) of the access.
 353          *
 354          * For any_acc, the access_bit_width is the largest width that is both
 355          * necessary and possible in an attempt to access the whole field in one
 356          * I/O operation.  However, for any_acc, the byte_alignment is always one
 357          * byte.
 358          *
 359          * For all Buffer Fields, the byte_alignment is always one byte.
 360          *
 361          * For all other access types (Byte, Word, Dword, Qword), the Bitwidth is
 362          * the same (equivalent) as the byte_alignment.
 363          */
 364         access_bit_width = acpi_ex_decode_field_access (obj_desc, field_flags,
 365                           &byte_alignment);
 366         if (!access_bit_width) {
 367                 return_ACPI_STATUS (AE_AML_OPERAND_VALUE);
 368         }
 369
 370         /* Setup width (access granularity) fields */
 371
 372         obj_desc->common_field.access_byte_width = (u8)
 373                         ACPI_DIV_8 (access_bit_width);          /* 1,  2,  4,  8 */
 374
 375         obj_desc->common_field.access_bit_width = (u8) access_bit_width;
 376
 377         /*
 378          * base_byte_offset is the address of the start of the field within the
 379          * region.  It is the byte address of the first *datum* (field-width data
 380          * unit) of the field. (i.e., the first datum that contains at least the
 381          * first *bit* of the field.)
 382          *
 383          * Note: byte_alignment is always either equal to the access_bit_width or 8
 384          * (Byte access), and it defines the addressing granularity of the parent
 385          * region or buffer.
 386          */
 387         nearest_byte_address =
 388                         ACPI_ROUND_BITS_DOWN_TO_BYTES (field_bit_position);
 389         obj_desc->common_field.base_byte_offset = (u32)
 390                         ACPI_ROUND_DOWN (nearest_byte_address, byte_alignment);
 391
 392         /*
 393          * start_field_bit_offset is the offset of the first bit of the field within
 394          * a field datum.
 395          */
 396         obj_desc->common_field.start_field_bit_offset = (u8)
 397                 (field_bit_position - ACPI_MUL_8 (obj_desc->common_field.base_byte_offset));
 398
 399         /*
 400          * Does the entire field fit within a single field access element? (datum)
 401          * (i.e., without crossing a datum boundary)
 402          */
 403         if ((obj_desc->common_field.start_field_bit_offset + field_bit_length) <=
 404                         (u16) access_bit_width) {
 405                 obj_desc->common.flags |= AOPOBJ_SINGLE_DATUM;
 406         }
 407
 408         return_ACPI_STATUS (AE_OK);
 409 }
 410
 411
 412 /*******************************************************************************
 413  *
 414  * FUNCTION:    acpi_ex_prep_field_value
 415  *
 416  * PARAMETERS:  Info    - Contains all field creation info
 417  *
 418  * RETURN:      Status
 419  *
 420  * DESCRIPTION: Construct an union acpi_operand_object of type def_field and
 421  *              connect it to the parent Node.
 422  *
 423  ******************************************************************************/
 424
 425 acpi_status
 426 acpi_ex_prep_field_value (
 427         struct acpi_create_field_info   *info)
 428 {
 429         union acpi_operand_object       *obj_desc;
 430         u32                             type;
 431         acpi_status                     status;
 432
 433
 434         ACPI_FUNCTION_TRACE ("ex_prep_field_value");
 435
 436
 437         /* Parameter validation */
 438
 439         if (info->field_type != ACPI_TYPE_LOCAL_INDEX_FIELD) {
 440                 if (!info->region_node) {
 441                         ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Null region_node\n"));
 442                         return_ACPI_STATUS (AE_AML_NO_OPERAND);
 443                 }
 444
 445                 type = acpi_ns_get_type (info->region_node);
 446                 if (type != ACPI_TYPE_REGION) {
 447                         ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
 448                                 "Needed Region, found type %X (%s)\n",
 449                                 type, acpi_ut_get_type_name (type)));
 450
 451                         return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
 452                 }
 453         }
 454
 455         /* Allocate a new field object */
 456
 457         obj_desc = acpi_ut_create_internal_object (info->field_type);
 458         if (!obj_desc) {
 459                 return_ACPI_STATUS (AE_NO_MEMORY);
 460         }
 461
 462         /* Initialize areas of the object that are common to all fields */
 463
 464         obj_desc->common_field.node = info->field_node;
 465         status = acpi_ex_prep_common_field_object (obj_desc, info->field_flags,
 466                          info->attribute, info->field_bit_position, info->field_bit_length);
 467         if (ACPI_FAILURE (status)) {
 468                 acpi_ut_delete_object_desc (obj_desc);
 469                 return_ACPI_STATUS (status);
 470         }
 471
 472         /* Initialize areas of the object that are specific to the field type */
 473
 474         switch (info->field_type) {
 475         case ACPI_TYPE_LOCAL_REGION_FIELD:
 476
 477                 obj_desc->field.region_obj = acpi_ns_get_attached_object (info->region_node);
 478
 479                 /* An additional reference for the container */
 480
 481                 acpi_ut_add_reference (obj_desc->field.region_obj);
 482
 483                 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
 484                         "region_field: bit_off %X, Off %X, Gran %X, Region %p\n",
 485                         obj_desc->field.start_field_bit_offset, obj_desc->field.base_byte_offset,
 486                         obj_desc->field.access_byte_width, obj_desc->field.region_obj));
 487                 break;
 488
 489
 490         case ACPI_TYPE_LOCAL_BANK_FIELD:
 491
 492                 obj_desc->bank_field.value   = info->bank_value;
 493                 obj_desc->bank_field.region_obj = acpi_ns_get_attached_object (
 494                                  info->region_node);
 495                 obj_desc->bank_field.bank_obj = acpi_ns_get_attached_object (
 496                                  info->register_node);
 497
 498                 /* An additional reference for the attached objects */
 499
 500                 acpi_ut_add_reference (obj_desc->bank_field.region_obj);
 501                 acpi_ut_add_reference (obj_desc->bank_field.bank_obj);
 502
 503                 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
 504                         "Bank Field: bit_off %X, Off %X, Gran %X, Region %p, bank_reg %p\n",
 505                         obj_desc->bank_field.start_field_bit_offset,
 506                         obj_desc->bank_field.base_byte_offset,
 507                         obj_desc->field.access_byte_width,
 508                         obj_desc->bank_field.region_obj,
 509                         obj_desc->bank_field.bank_obj));
 510                 break;
 511
 512
 513         case ACPI_TYPE_LOCAL_INDEX_FIELD:
 514
 515                 obj_desc->index_field.index_obj = acpi_ns_get_attached_object (
 516                                  info->register_node);
 517                 obj_desc->index_field.data_obj = acpi_ns_get_attached_object (
 518                                  info->data_register_node);
 519                 obj_desc->index_field.value  = (u32)
 520                         (info->field_bit_position / ACPI_MUL_8 (
 521                                           obj_desc->field.access_byte_width));
 522
 523                 if (!obj_desc->index_field.data_obj || !obj_desc->index_field.index_obj) {
 524                         ACPI_REPORT_ERROR (("Null Index Object during field prep\n"));
 525                         acpi_ut_delete_object_desc (obj_desc);
 526                         return_ACPI_STATUS (AE_AML_INTERNAL);
 527                 }
 528
 529                 /* An additional reference for the attached objects */
 530
 531                 acpi_ut_add_reference (obj_desc->index_field.data_obj);
 532                 acpi_ut_add_reference (obj_desc->index_field.index_obj);
 533
 534                 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
 535                         "index_field: bit_off %X, Off %X, Value %X, Gran %X, Index %p, Data %p\n",
 536                         obj_desc->index_field.start_field_bit_offset,
 537                         obj_desc->index_field.base_byte_offset,
 538                         obj_desc->index_field.value,
 539                         obj_desc->field.access_byte_width,
 540                         obj_desc->index_field.index_obj,
 541                         obj_desc->index_field.data_obj));
 542                 break;
 543
 544         default:
 545                 /* No other types should get here */
 546                 break;
 547         }
 548
 549         /*
 550          * Store the constructed descriptor (obj_desc) into the parent Node,
 551          * preserving the current type of that named_obj.
 552          */
 553         status = acpi_ns_attach_object (info->field_node, obj_desc,
 554                           acpi_ns_get_type (info->field_node));
 555
 556         ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD, "Set named_obj %p [%4.4s], obj_desc %p\n",
 557                         info->field_node, acpi_ut_get_node_name (info->field_node), obj_desc));
 558
 559         /* Remove local reference to the object */
 560
 561         acpi_ut_remove_reference (obj_desc);
 562         return_ACPI_STATUS (status);
 563 }
 564