err.no 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 - 2007, 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 #include <acpi/acpi.h>
  46 #include <acpi/acinterp.h>
  47 #include <acpi/amlcode.h>
  48 #include <acpi/acnamesp.h>
  49
  50 #define _COMPONENT          ACPI_EXECUTER
  51 ACPI_MODULE_NAME("exprep")
  52
  53 /* Local prototypes */
  54 static u32
  55 acpi_ex_decode_field_access(union acpi_operand_object *obj_desc,
  56                             u8 field_flags, u32 * return_byte_alignment);
  57
  58 #ifdef ACPI_UNDER_DEVELOPMENT
  59
  60 static u32
  61 acpi_ex_generate_access(u32 field_bit_offset,
  62                         u32 field_bit_length, u32 region_length);
  63
  64 /*******************************************************************************
  65  *
  66  * FUNCTION:    acpi_ex_generate_access
  67  *
  68  * PARAMETERS:  field_bit_offset    - Start of field within parent region/buffer
  69  *              field_bit_length    - Length of field in bits
  70  *              region_length       - Length of parent in bytes
  71  *
  72  * RETURN:      Field granularity (8, 16, 32 or 64) and
  73  *              byte_alignment (1, 2, 3, or 4)
  74  *
  75  * DESCRIPTION: Generate an optimal access width for fields defined with the
  76  *              any_acc keyword.
  77  *
  78  * NOTE: Need to have the region_length in order to check for boundary
  79  *       conditions (end-of-region).  However, the region_length is a deferred
  80  *       operation.  Therefore, to complete this implementation, the generation
  81  *       of this access width must be deferred until the region length has
  82  *       been evaluated.
  83  *
  84  ******************************************************************************/
  85
  86 static u32
  87 acpi_ex_generate_access(u32 field_bit_offset,
  88                         u32 field_bit_length, u32 region_length)
  89 {
  90         u32 field_byte_length;
  91         u32 field_byte_offset;
  92         u32 field_byte_end_offset;
  93         u32 access_byte_width;
  94         u32 field_start_offset;
  95         u32 field_end_offset;
  96         u32 minimum_access_width = 0xFFFFFFFF;
  97         u32 minimum_accesses = 0xFFFFFFFF;
  98         u32 accesses;
  99
 100         ACPI_FUNCTION_TRACE(ex_generate_access);
 101
 102         /* Round Field start offset and length to "minimal" byte boundaries */
 103
 104         field_byte_offset = ACPI_DIV_8(ACPI_ROUND_DOWN(field_bit_offset, 8));
 105         field_byte_end_offset = ACPI_DIV_8(ACPI_ROUND_UP(field_bit_length +
 106                                                          field_bit_offset, 8));
 107         field_byte_length = field_byte_end_offset - field_byte_offset;
 108
 109         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 110                           "Bit length %d, Bit offset %d\n",
 111                           field_bit_length, field_bit_offset));
 112
 113         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 114                           "Byte Length %d, Byte Offset %d, End Offset %d\n",
 115                           field_byte_length, field_byte_offset,
 116                           field_byte_end_offset));
 117
 118         /*
 119          * Iterative search for the maximum access width that is both aligned
 120          * and does not go beyond the end of the region
 121          *
 122          * Start at byte_acc and work upwards to qword_acc max. (1,2,4,8 bytes)
 123          */
 124         for (access_byte_width = 1; access_byte_width <= 8;
 125              access_byte_width <<= 1) {
 126                 /*
 127                  * 1) Round end offset up to next access boundary and make sure that
 128                  *    this does not go beyond the end of the parent region.
 129                  * 2) When the Access width is greater than the field_byte_length, we
 130                  *    are done. (This does not optimize for the perfectly aligned
 131                  *    case yet).
 132                  */
 133                 if (ACPI_ROUND_UP(field_byte_end_offset, access_byte_width) <=
 134                     region_length) {
 135                         field_start_offset =
 136                             ACPI_ROUND_DOWN(field_byte_offset,
 137                                             access_byte_width) /
 138                             access_byte_width;
 139
 140                         field_end_offset =
 141                             ACPI_ROUND_UP((field_byte_length +
 142                                            field_byte_offset),
 143                                           access_byte_width) /
 144                             access_byte_width;
 145
 146                         accesses = field_end_offset - field_start_offset;
 147
 148                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 149                                           "AccessWidth %d end is within region\n",
 150                                           access_byte_width));
 151
 152                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 153                                           "Field Start %d, Field End %d -- requires %d accesses\n",
 154                                           field_start_offset, field_end_offset,
 155                                           accesses));
 156
 157                         /* Single access is optimal */
 158
 159                         if (accesses <= 1) {
 160                                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 161                                                   "Entire field can be accessed with one operation of size %d\n",
 162                                                   access_byte_width));
 163                                 return_VALUE(access_byte_width);
 164                         }
 165
 166                         /*
 167                          * Fits in the region, but requires more than one read/write.
 168                          * try the next wider access on next iteration
 169                          */
 170                         if (accesses < minimum_accesses) {
 171                                 minimum_accesses = accesses;
 172                                 minimum_access_width = access_byte_width;
 173                         }
 174                 } else {
 175                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 176                                           "AccessWidth %d end is NOT within region\n",
 177                                           access_byte_width));
 178                         if (access_byte_width == 1) {
 179                                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 180                                                   "Field goes beyond end-of-region!\n"));
 181
 182                                 /* Field does not fit in the region at all */
 183
 184                                 return_VALUE(0);
 185                         }
 186
 187                         /*
 188                          * This width goes beyond the end-of-region, back off to
 189                          * previous access
 190                          */
 191                         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 192                                           "Backing off to previous optimal access width of %d\n",
 193                                           minimum_access_width));
 194                         return_VALUE(minimum_access_width);
 195                 }
 196         }
 197
 198         /*
 199          * Could not read/write field with one operation,
 200          * just use max access width
 201          */
 202         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 203                           "Cannot access field in one operation, using width 8\n"));
 204         return_VALUE(8);
 205 }
 206 #endif                          /* ACPI_UNDER_DEVELOPMENT */
 207
 208 /*******************************************************************************
 209  *
 210  * FUNCTION:    acpi_ex_decode_field_access
 211  *
 212  * PARAMETERS:  obj_desc            - Field object
 213  *              field_flags         - Encoded fieldflags (contains access bits)
 214  *              return_byte_alignment - Where the byte alignment is returned
 215  *
 216  * RETURN:      Field granularity (8, 16, 32 or 64) and
 217  *              byte_alignment (1, 2, 3, or 4)
 218  *
 219  * DESCRIPTION: Decode the access_type bits of a field definition.
 220  *
 221  ******************************************************************************/
 222
 223 static u32
 224 acpi_ex_decode_field_access(union acpi_operand_object *obj_desc,
 225                             u8 field_flags, u32 * return_byte_alignment)
 226 {
 227         u32 access;
 228         u32 byte_alignment;
 229         u32 bit_length;
 230
 231         ACPI_FUNCTION_TRACE(ex_decode_field_access);
 232
 233         access = (field_flags & AML_FIELD_ACCESS_TYPE_MASK);
 234
 235         switch (access) {
 236         case AML_FIELD_ACCESS_ANY:
 237
 238 #ifdef ACPI_UNDER_DEVELOPMENT
 239                 byte_alignment =
 240                     acpi_ex_generate_access(obj_desc->common_field.
 241                                             start_field_bit_offset,
 242                                             obj_desc->common_field.bit_length,
 243                                             0xFFFFFFFF
 244                                             /* Temp until we pass region_length as parameter */
 245                     );
 246                 bit_length = byte_alignment * 8;
 247 #endif
 248
 249                 byte_alignment = 1;
 250                 bit_length = 8;
 251                 break;
 252
 253         case AML_FIELD_ACCESS_BYTE:
 254         case AML_FIELD_ACCESS_BUFFER:   /* ACPI 2.0 (SMBus Buffer) */
 255                 byte_alignment = 1;
 256                 bit_length = 8;
 257                 break;
 258
 259         case AML_FIELD_ACCESS_WORD:
 260                 byte_alignment = 2;
 261                 bit_length = 16;
 262                 break;
 263
 264         case AML_FIELD_ACCESS_DWORD:
 265                 byte_alignment = 4;
 266                 bit_length = 32;
 267                 break;
 268
 269         case AML_FIELD_ACCESS_QWORD:    /* ACPI 2.0 */
 270                 byte_alignment = 8;
 271                 bit_length = 64;
 272                 break;
 273
 274         default:
 275                 /* Invalid field access type */
 276
 277                 ACPI_ERROR((AE_INFO, "Unknown field access type %X", access));
 278                 return_UINT32(0);
 279         }
 280
 281         if (ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_BUFFER_FIELD) {
 282                 /*
 283                  * buffer_field access can be on any byte boundary, so the
 284                  * byte_alignment is always 1 byte -- regardless of any byte_alignment
 285                  * implied by the field access type.
 286                  */
 287                 byte_alignment = 1;
 288         }
 289
 290         *return_byte_alignment = byte_alignment;
 291         return_UINT32(bit_length);
 292 }
 293
 294 /*******************************************************************************
 295  *
 296  * FUNCTION:    acpi_ex_prep_common_field_object
 297  *
 298  * PARAMETERS:  obj_desc            - The field object
 299  *              field_flags         - Access, lock_rule, and update_rule.
 300  *                                    The format of a field_flag is described
 301  *                                    in the ACPI specification
 302  *              field_attribute     - Special attributes (not used)
 303  *              field_bit_position  - Field start position
 304  *              field_bit_length    - Field length in number of bits
 305  *
 306  * RETURN:      Status
 307  *
 308  * DESCRIPTION: Initialize the areas of the field object that are common
 309  *              to the various types of fields.  Note: This is very "sensitive"
 310  *              code because we are solving the general case for field
 311  *              alignment.
 312  *
 313  ******************************************************************************/
 314
 315 acpi_status
 316 acpi_ex_prep_common_field_object(union acpi_operand_object *obj_desc,
 317                                  u8 field_flags,
 318                                  u8 field_attribute,
 319                                  u32 field_bit_position, u32 field_bit_length)
 320 {
 321         u32 access_bit_width;
 322         u32 byte_alignment;
 323         u32 nearest_byte_address;
 324
 325         ACPI_FUNCTION_TRACE(ex_prep_common_field_object);
 326
 327         /*
 328          * Note: the structure being initialized is the
 329          * ACPI_COMMON_FIELD_INFO;  No structure fields outside of the common
 330          * area are initialized by this procedure.
 331          */
 332         obj_desc->common_field.field_flags = field_flags;
 333         obj_desc->common_field.attribute = field_attribute;
 334         obj_desc->common_field.bit_length = field_bit_length;
 335
 336         /*
 337          * Decode the access type so we can compute offsets.  The access type gives
 338          * two pieces of information - the width of each field access and the
 339          * necessary byte_alignment (address granularity) of the access.
 340          *
 341          * For any_acc, the access_bit_width is the largest width that is both
 342          * necessary and possible in an attempt to access the whole field in one
 343          * I/O operation.  However, for any_acc, the byte_alignment is always one
 344          * byte.
 345          *
 346          * For all Buffer Fields, the byte_alignment is always one byte.
 347          *
 348          * For all other access types (Byte, Word, Dword, Qword), the Bitwidth is
 349          * the same (equivalent) as the byte_alignment.
 350          */
 351         access_bit_width = acpi_ex_decode_field_access(obj_desc, field_flags,
 352                                                        &byte_alignment);
 353         if (!access_bit_width) {
 354                 return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
 355         }
 356
 357         /* Setup width (access granularity) fields */
 358
 359         obj_desc->common_field.access_byte_width = (u8)
 360             ACPI_DIV_8(access_bit_width);       /* 1,  2,  4,  8 */
 361
 362         obj_desc->common_field.access_bit_width = (u8) access_bit_width;
 363
 364         /*
 365          * base_byte_offset is the address of the start of the field within the
 366          * region.  It is the byte address of the first *datum* (field-width data
 367          * unit) of the field. (i.e., the first datum that contains at least the
 368          * first *bit* of the field.)
 369          *
 370          * Note: byte_alignment is always either equal to the access_bit_width or 8
 371          * (Byte access), and it defines the addressing granularity of the parent
 372          * region or buffer.
 373          */
 374         nearest_byte_address =
 375             ACPI_ROUND_BITS_DOWN_TO_BYTES(field_bit_position);
 376         obj_desc->common_field.base_byte_offset = (u32)
 377             ACPI_ROUND_DOWN(nearest_byte_address, byte_alignment);
 378
 379         /*
 380          * start_field_bit_offset is the offset of the first bit of the field within
 381          * a field datum.
 382          */
 383         obj_desc->common_field.start_field_bit_offset = (u8)
 384             (field_bit_position -
 385              ACPI_MUL_8(obj_desc->common_field.base_byte_offset));
 386
 387         /*
 388          * Does the entire field fit within a single field access element? (datum)
 389          * (i.e., without crossing a datum boundary)
 390          */
 391         if ((obj_desc->common_field.start_field_bit_offset +
 392              field_bit_length) <= (u16) access_bit_width) {
 393                 obj_desc->common.flags |= AOPOBJ_SINGLE_DATUM;
 394         }
 395
 396         return_ACPI_STATUS(AE_OK);
 397 }
 398
 399 /*******************************************************************************
 400  *
 401  * FUNCTION:    acpi_ex_prep_field_value
 402  *
 403  * PARAMETERS:  Info    - Contains all field creation info
 404  *
 405  * RETURN:      Status
 406  *
 407  * DESCRIPTION: Construct an union acpi_operand_object of type def_field and
 408  *              connect it to the parent Node.
 409  *
 410  ******************************************************************************/
 411
 412 acpi_status acpi_ex_prep_field_value(struct acpi_create_field_info *info)
 413 {
 414         union acpi_operand_object *obj_desc;
 415         u32 type;
 416         acpi_status status;
 417
 418         ACPI_FUNCTION_TRACE(ex_prep_field_value);
 419
 420         /* Parameter validation */
 421
 422         if (info->field_type != ACPI_TYPE_LOCAL_INDEX_FIELD) {
 423                 if (!info->region_node) {
 424                         ACPI_ERROR((AE_INFO, "Null RegionNode"));
 425                         return_ACPI_STATUS(AE_AML_NO_OPERAND);
 426                 }
 427
 428                 type = acpi_ns_get_type(info->region_node);
 429                 if (type != ACPI_TYPE_REGION) {
 430                         ACPI_ERROR((AE_INFO,
 431                                     "Needed Region, found type %X (%s)",
 432                                     type, acpi_ut_get_type_name(type)));
 433
 434                         return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
 435                 }
 436         }
 437
 438         /* Allocate a new field object */
 439
 440         obj_desc = acpi_ut_create_internal_object(info->field_type);
 441         if (!obj_desc) {
 442                 return_ACPI_STATUS(AE_NO_MEMORY);
 443         }
 444
 445         /* Initialize areas of the object that are common to all fields */
 446
 447         obj_desc->common_field.node = info->field_node;
 448         status = acpi_ex_prep_common_field_object(obj_desc, info->field_flags,
 449                                                   info->attribute,
 450                                                   info->field_bit_position,
 451                                                   info->field_bit_length);
 452         if (ACPI_FAILURE(status)) {
 453                 acpi_ut_delete_object_desc(obj_desc);
 454                 return_ACPI_STATUS(status);
 455         }
 456
 457         /* Initialize areas of the object that are specific to the field type */
 458
 459         switch (info->field_type) {
 460         case ACPI_TYPE_LOCAL_REGION_FIELD:
 461
 462                 obj_desc->field.region_obj =
 463                     acpi_ns_get_attached_object(info->region_node);
 464
 465                 /* An additional reference for the container */
 466
 467                 acpi_ut_add_reference(obj_desc->field.region_obj);
 468
 469                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 470                                   "RegionField: BitOff %X, Off %X, Gran %X, Region %p\n",
 471                                   obj_desc->field.start_field_bit_offset,
 472                                   obj_desc->field.base_byte_offset,
 473                                   obj_desc->field.access_byte_width,
 474                                   obj_desc->field.region_obj));
 475                 break;
 476
 477         case ACPI_TYPE_LOCAL_BANK_FIELD:
 478
 479                 obj_desc->bank_field.value = info->bank_value;
 480                 obj_desc->bank_field.region_obj =
 481                     acpi_ns_get_attached_object(info->region_node);
 482                 obj_desc->bank_field.bank_obj =
 483                     acpi_ns_get_attached_object(info->register_node);
 484
 485                 /* An additional reference for the attached objects */
 486
 487                 acpi_ut_add_reference(obj_desc->bank_field.region_obj);
 488                 acpi_ut_add_reference(obj_desc->bank_field.bank_obj);
 489
 490                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 491                                   "Bank Field: BitOff %X, Off %X, Gran %X, Region %p, BankReg %p\n",
 492                                   obj_desc->bank_field.start_field_bit_offset,
 493                                   obj_desc->bank_field.base_byte_offset,
 494                                   obj_desc->field.access_byte_width,
 495                                   obj_desc->bank_field.region_obj,
 496                                   obj_desc->bank_field.bank_obj));
 497                 break;
 498
 499         case ACPI_TYPE_LOCAL_INDEX_FIELD:
 500
 501                 /* Get the Index and Data registers */
 502
 503                 obj_desc->index_field.index_obj =
 504                     acpi_ns_get_attached_object(info->register_node);
 505                 obj_desc->index_field.data_obj =
 506                     acpi_ns_get_attached_object(info->data_register_node);
 507
 508                 if (!obj_desc->index_field.data_obj
 509                     || !obj_desc->index_field.index_obj) {
 510                         ACPI_ERROR((AE_INFO,
 511                                     "Null Index Object during field prep"));
 512                         acpi_ut_delete_object_desc(obj_desc);
 513                         return_ACPI_STATUS(AE_AML_INTERNAL);
 514                 }
 515
 516                 /* An additional reference for the attached objects */
 517
 518                 acpi_ut_add_reference(obj_desc->index_field.data_obj);
 519                 acpi_ut_add_reference(obj_desc->index_field.index_obj);
 520
 521                 /*
 522                  * April 2006: Changed to match MS behavior
 523                  *
 524                  * The value written to the Index register is the byte offset of the
 525                  * target field in units of the granularity of the index_field
 526                  *
 527                  * Previously, the value was calculated as an index in terms of the
 528                  * width of the Data register, as below:
 529                  *
 530                  *      obj_desc->index_field.Value = (u32)
 531                  *          (Info->field_bit_position / ACPI_MUL_8 (
 532                  *              obj_desc->Field.access_byte_width));
 533                  *
 534                  * February 2006: Tried value as a byte offset:
 535                  *      obj_desc->index_field.Value = (u32)
 536                  *          ACPI_DIV_8 (Info->field_bit_position);
 537                  */
 538                 obj_desc->index_field.value =
 539                     (u32) ACPI_ROUND_DOWN(ACPI_DIV_8(info->field_bit_position),
 540                                           obj_desc->index_field.
 541                                           access_byte_width);
 542
 543                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 544                                   "IndexField: BitOff %X, Off %X, Value %X, Gran %X, Index %p, Data %p\n",
 545                                   obj_desc->index_field.start_field_bit_offset,
 546                                   obj_desc->index_field.base_byte_offset,
 547                                   obj_desc->index_field.value,
 548                                   obj_desc->field.access_byte_width,
 549                                   obj_desc->index_field.index_obj,
 550                                   obj_desc->index_field.data_obj));
 551                 break;
 552
 553         default:
 554                 /* No other types should get here */
 555                 break;
 556         }
 557
 558         /*
 559          * Store the constructed descriptor (obj_desc) into the parent Node,
 560          * preserving the current type of that named_obj.
 561          */
 562         status = acpi_ns_attach_object(info->field_node, obj_desc,
 563                                        acpi_ns_get_type(info->field_node));
 564
 565         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 566                           "Set NamedObj %p [%4.4s], ObjDesc %p\n",
 567                           info->field_node,
 568                           acpi_ut_get_node_name(info->field_node), obj_desc));
 569
 570         /* Remove local reference to the object */
 571
 572         acpi_ut_remove_reference(obj_desc);
 573         return_ACPI_STATUS(status);
 574 }