acpi/acpica/exprep.c

0001 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
0002 /******************************************************************************
0003  *
0004  * Module Name: exprep - ACPI AML field prep utilities
0005  *
0006  * Copyright (C) 2000 - 2022, Intel Corp.
0007  *
0008  *****************************************************************************/
0009
0010 #include <acpi/acpi.h>
0011 #include "accommon.h"
0012 #include "acinterp.h"
0013 #include "amlcode.h"
0014 #include "acnamesp.h"
0015 #include "acdispat.h"
0016
0017 #define _COMPONENT          ACPI_EXECUTER
0018 ACPI_MODULE_NAME("exprep")
0019
0020 /* Local prototypes */
0021 static u32
0022 acpi_ex_decode_field_access(union acpi_operand_object *obj_desc,
0023                 u8 field_flags, u32 * return_byte_alignment);
0024
0025 #ifdef ACPI_UNDER_DEVELOPMENT
0026
0027 static u32
0028 acpi_ex_generate_access(u32 field_bit_offset,
0029             u32 field_bit_length, u32 region_length);
0030
0031 /*******************************************************************************
0032  *
0033  * FUNCTION:    acpi_ex_generate_access
0034  *
0035  * PARAMETERS:  field_bit_offset    - Start of field within parent region/buffer
0036  *              field_bit_length    - Length of field in bits
0037  *              region_length       - Length of parent in bytes
0038  *
0039  * RETURN:      Field granularity (8, 16, 32 or 64) and
0040  *              byte_alignment (1, 2, 3, or 4)
0041  *
0042  * DESCRIPTION: Generate an optimal access width for fields defined with the
0043  *              any_acc keyword.
0044  *
0045  * NOTE: Need to have the region_length in order to check for boundary
0046  *       conditions (end-of-region). However, the region_length is a deferred
0047  *       operation. Therefore, to complete this implementation, the generation
0048  *       of this access width must be deferred until the region length has
0049  *       been evaluated.
0050  *
0051  ******************************************************************************/
0052
0053 static u32
0054 acpi_ex_generate_access(u32 field_bit_offset,
0055             u32 field_bit_length, u32 region_length)
0056 {
0057     u32 field_byte_length;
0058     u32 field_byte_offset;
0059     u32 field_byte_end_offset;
0060     u32 access_byte_width;
0061     u32 field_start_offset;
0062     u32 field_end_offset;
0063     u32 minimum_access_width = 0xFFFFFFFF;
0064     u32 minimum_accesses = 0xFFFFFFFF;
0065     u32 accesses;
0066
0067     ACPI_FUNCTION_TRACE(ex_generate_access);
0068
0069     /* Round Field start offset and length to "minimal" byte boundaries */
0070
0071     field_byte_offset = ACPI_DIV_8(ACPI_ROUND_DOWN(field_bit_offset, 8));
0072
0073     field_byte_end_offset =
0074         ACPI_DIV_8(ACPI_ROUND_UP(field_bit_length + field_bit_offset, 8));
0075
0076     field_byte_length = field_byte_end_offset - field_byte_offset;
0077
0078     ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
0079               "Bit length %u, Bit offset %u\n",
0080               field_bit_length, field_bit_offset));
0081
0082     ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
0083               "Byte Length %u, Byte Offset %u, End Offset %u\n",
0084               field_byte_length, field_byte_offset,
0085               field_byte_end_offset));
0086
0087     /*
0088      * Iterative search for the maximum access width that is both aligned
0089      * and does not go beyond the end of the region
0090      *
0091      * Start at byte_acc and work upwards to qword_acc max. (1,2,4,8 bytes)
0092      */
0093     for (access_byte_width = 1; access_byte_width <= 8;
0094          access_byte_width <<= 1) {
0095         /*
0096          * 1) Round end offset up to next access boundary and make sure that
0097          *    this does not go beyond the end of the parent region.
0098          * 2) When the Access width is greater than the field_byte_length, we
0099          *    are done. (This does not optimize for the perfectly aligned
0100          *    case yet).
0101          */
0102         if (ACPI_ROUND_UP(field_byte_end_offset, access_byte_width) <=
0103             region_length) {
0104             field_start_offset =
0105                 ACPI_ROUND_DOWN(field_byte_offset,
0106                         access_byte_width) /
0107                 access_byte_width;
0108
0109             field_end_offset =
0110                 ACPI_ROUND_UP((field_byte_length +
0111                        field_byte_offset),
0112                       access_byte_width) /
0113                 access_byte_width;
0114
0115             accesses = field_end_offset - field_start_offset;
0116
0117             ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
0118                       "AccessWidth %u end is within region\n",
0119                       access_byte_width));
0120
0121             ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
0122                       "Field Start %u, Field End %u -- requires %u accesses\n",
0123                       field_start_offset, field_end_offset,
0124                       accesses));
0125
0126             /* Single access is optimal */
0127
0128             if (accesses <= 1) {
0129                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
0130                           "Entire field can be accessed "
0131                           "with one operation of size %u\n",
0132                           access_byte_width));
0133                 return_VALUE(access_byte_width);
0134             }
0135
0136             /*
0137              * Fits in the region, but requires more than one read/write.
0138              * try the next wider access on next iteration
0139              */
0140             if (accesses < minimum_accesses) {
0141                 minimum_accesses = accesses;
0142                 minimum_access_width = access_byte_width;
0143             }
0144         } else {
0145             ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
0146                       "AccessWidth %u end is NOT within region\n",
0147                       access_byte_width));
0148             if (access_byte_width == 1) {
0149                 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
0150                           "Field goes beyond end-of-region!\n"));
0151
0152                 /* Field does not fit in the region at all */
0153
0154                 return_VALUE(0);
0155             }
0156
0157             /*
0158              * This width goes beyond the end-of-region, back off to
0159              * previous access
0160              */
0161             ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
0162                       "Backing off to previous optimal access width of %u\n",
0163                       minimum_access_width));
0164             return_VALUE(minimum_access_width);
0165         }
0166     }
0167
0168     /*
0169      * Could not read/write field with one operation,
0170      * just use max access width
0171      */
0172     ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
0173               "Cannot access field in one operation, using width 8\n"));
0174
0175     return_VALUE(8);
0176 }
0177 #endif              /* ACPI_UNDER_DEVELOPMENT */
0178
0179 /*******************************************************************************
0180  *
0181  * FUNCTION:    acpi_ex_decode_field_access
0182  *
0183  * PARAMETERS:  obj_desc            - Field object
0184  *              field_flags         - Encoded fieldflags (contains access bits)
0185  *              return_byte_alignment - Where the byte alignment is returned
0186  *
0187  * RETURN:      Field granularity (8, 16, 32 or 64) and
0188  *              byte_alignment (1, 2, 3, or 4)
0189  *
0190  * DESCRIPTION: Decode the access_type bits of a field definition.
0191  *
0192  ******************************************************************************/
0193
0194 static u32
0195 acpi_ex_decode_field_access(union acpi_operand_object *obj_desc,
0196                 u8 field_flags, u32 * return_byte_alignment)
0197 {
0198     u32 access;
0199     u32 byte_alignment;
0200     u32 bit_length;
0201
0202     ACPI_FUNCTION_TRACE(ex_decode_field_access);
0203
0204     access = (field_flags & AML_FIELD_ACCESS_TYPE_MASK);
0205
0206     switch (access) {
0207     case AML_FIELD_ACCESS_ANY:
0208
0209 #ifdef ACPI_UNDER_DEVELOPMENT
0210         byte_alignment =
0211             acpi_ex_generate_access(obj_desc->common_field.
0212                         start_field_bit_offset,
0213                         obj_desc->common_field.bit_length,
0214                         0xFFFFFFFF
0215                         /* Temp until we pass region_length as parameter */
0216             );
0217         bit_length = byte_alignment * 8;
0218 #endif
0219
0220         byte_alignment = 1;
0221         bit_length = 8;
0222         break;
0223
0224     case AML_FIELD_ACCESS_BYTE:
0225     case AML_FIELD_ACCESS_BUFFER:   /* ACPI 2.0 (SMBus Buffer) */
0226
0227         byte_alignment = 1;
0228         bit_length = 8;
0229         break;
0230
0231     case AML_FIELD_ACCESS_WORD:
0232
0233         byte_alignment = 2;
0234         bit_length = 16;
0235         break;
0236
0237     case AML_FIELD_ACCESS_DWORD:
0238
0239         byte_alignment = 4;
0240         bit_length = 32;
0241         break;
0242
0243     case AML_FIELD_ACCESS_QWORD:    /* ACPI 2.0 */
0244
0245         byte_alignment = 8;
0246         bit_length = 64;
0247         break;
0248
0249     default:
0250
0251         /* Invalid field access type */
0252
0253         ACPI_ERROR((AE_INFO, "Unknown field access type 0x%X", access));
0254
0255         return_UINT32(0);
0256     }
0257
0258     if (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD) {
0259         /*
0260          * buffer_field access can be on any byte boundary, so the
0261          * byte_alignment is always 1 byte -- regardless of any byte_alignment
0262          * implied by the field access type.
0263          */
0264         byte_alignment = 1;
0265     }
0266
0267     *return_byte_alignment = byte_alignment;
0268     return_UINT32(bit_length);
0269 }
0270
0271 /*******************************************************************************
0272  *
0273  * FUNCTION:    acpi_ex_prep_common_field_object
0274  *
0275  * PARAMETERS:  obj_desc            - The field object
0276  *              field_flags         - Access, lock_rule, and update_rule.
0277  *                                    The format of a field_flag is described
0278  *                                    in the ACPI specification
0279  *              field_attribute     - Special attributes (not used)
0280  *              field_bit_position  - Field start position
0281  *              field_bit_length    - Field length in number of bits
0282  *
0283  * RETURN:      Status
0284  *
0285  * DESCRIPTION: Initialize the areas of the field object that are common
0286  *              to the various types of fields. Note: This is very "sensitive"
0287  *              code because we are solving the general case for field
0288  *              alignment.
0289  *
0290  ******************************************************************************/
0291
0292 acpi_status
0293 acpi_ex_prep_common_field_object(union acpi_operand_object *obj_desc,
0294                  u8 field_flags,
0295                  u8 field_attribute,
0296                  u32 field_bit_position, u32 field_bit_length)
0297 {
0298     u32 access_bit_width;
0299     u32 byte_alignment;
0300     u32 nearest_byte_address;
0301
0302     ACPI_FUNCTION_TRACE(ex_prep_common_field_object);
0303
0304     /*
0305      * Note: the structure being initialized is the
0306      * ACPI_COMMON_FIELD_INFO;  No structure fields outside of the common
0307      * area are initialized by this procedure.
0308      */
0309     obj_desc->common_field.field_flags = field_flags;
0310     obj_desc->common_field.attribute = field_attribute;
0311     obj_desc->common_field.bit_length = field_bit_length;
0312
0313     /*
0314      * Decode the access type so we can compute offsets. The access type gives
0315      * two pieces of information - the width of each field access and the
0316      * necessary byte_alignment (address granularity) of the access.
0317      *
0318      * For any_acc, the access_bit_width is the largest width that is both
0319      * necessary and possible in an attempt to access the whole field in one
0320      * I/O operation. However, for any_acc, the byte_alignment is always one
0321      * byte.
0322      *
0323      * For all Buffer Fields, the byte_alignment is always one byte.
0324      *
0325      * For all other access types (Byte, Word, Dword, Qword), the Bitwidth is
0326      * the same (equivalent) as the byte_alignment.
0327      */
0328     access_bit_width =
0329         acpi_ex_decode_field_access(obj_desc, field_flags, &byte_alignment);
0330     if (!access_bit_width) {
0331         return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
0332     }
0333
0334     /* Setup width (access granularity) fields (values are: 1, 2, 4, 8) */
0335
0336     obj_desc->common_field.access_byte_width = (u8)
0337         ACPI_DIV_8(access_bit_width);
0338
0339     /*
0340      * base_byte_offset is the address of the start of the field within the
0341      * region. It is the byte address of the first *datum* (field-width data
0342      * unit) of the field. (i.e., the first datum that contains at least the
0343      * first *bit* of the field.)
0344      *
0345      * Note: byte_alignment is always either equal to the access_bit_width or 8
0346      * (Byte access), and it defines the addressing granularity of the parent
0347      * region or buffer.
0348      */
0349     nearest_byte_address =
0350         ACPI_ROUND_BITS_DOWN_TO_BYTES(field_bit_position);
0351     obj_desc->common_field.base_byte_offset = (u32)
0352         ACPI_ROUND_DOWN(nearest_byte_address, byte_alignment);
0353
0354     /*
0355      * start_field_bit_offset is the offset of the first bit of the field within
0356      * a field datum.
0357      */
0358     obj_desc->common_field.start_field_bit_offset = (u8)
0359         (field_bit_position -
0360          ACPI_MUL_8(obj_desc->common_field.base_byte_offset));
0361
0362     return_ACPI_STATUS(AE_OK);
0363 }
0364
0365 /*******************************************************************************
0366  *
0367  * FUNCTION:    acpi_ex_prep_field_value
0368  *
0369  * PARAMETERS:  info    - Contains all field creation info
0370  *
0371  * RETURN:      Status
0372  *
0373  * DESCRIPTION: Construct an object of type union acpi_operand_object with a
0374  *              subtype of def_field and connect it to the parent Node.
0375  *
0376  ******************************************************************************/
0377
0378 acpi_status acpi_ex_prep_field_value(struct acpi_create_field_info *info)
0379 {
0380     union acpi_operand_object *obj_desc;
0381     union acpi_operand_object *second_desc = NULL;
0382     acpi_status status;
0383     u32 access_byte_width;
0384     u32 type;
0385
0386     ACPI_FUNCTION_TRACE(ex_prep_field_value);
0387
0388     /* Parameter validation */
0389
0390     if (info->field_type != ACPI_TYPE_LOCAL_INDEX_FIELD) {
0391         if (!info->region_node) {
0392             ACPI_ERROR((AE_INFO, "Null RegionNode"));
0393             return_ACPI_STATUS(AE_AML_NO_OPERAND);
0394         }
0395
0396         type = acpi_ns_get_type(info->region_node);
0397         if (type != ACPI_TYPE_REGION) {
0398             ACPI_ERROR((AE_INFO,
0399                     "Needed Region, found type 0x%X (%s)", type,
0400                     acpi_ut_get_type_name(type)));
0401
0402             return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
0403         }
0404     }
0405
0406     /* Allocate a new field object */
0407
0408     obj_desc = acpi_ut_create_internal_object(info->field_type);
0409     if (!obj_desc) {
0410         return_ACPI_STATUS(AE_NO_MEMORY);
0411     }
0412
0413     /* Initialize areas of the object that are common to all fields */
0414
0415     obj_desc->common_field.node = info->field_node;
0416     status = acpi_ex_prep_common_field_object(obj_desc,
0417                           info->field_flags,
0418                           info->attribute,
0419                           info->field_bit_position,
0420                           info->field_bit_length);
0421     if (ACPI_FAILURE(status)) {
0422         acpi_ut_delete_object_desc(obj_desc);
0423         return_ACPI_STATUS(status);
0424     }
0425
0426     /* Initialize areas of the object that are specific to the field type */
0427
0428     switch (info->field_type) {
0429     case ACPI_TYPE_LOCAL_REGION_FIELD:
0430
0431         obj_desc->field.region_obj =
0432             acpi_ns_get_attached_object(info->region_node);
0433
0434         /* Fields specific to generic_serial_bus fields */
0435
0436         obj_desc->field.access_length = info->access_length;
0437
0438         if (info->connection_node) {
0439             second_desc = info->connection_node->object;
0440             if (!(second_desc->common.flags & AOPOBJ_DATA_VALID)) {
0441                 status =
0442                     acpi_ds_get_buffer_arguments(second_desc);
0443                 if (ACPI_FAILURE(status)) {
0444                     acpi_ut_delete_object_desc(obj_desc);
0445                     return_ACPI_STATUS(status);
0446                 }
0447             }
0448
0449             obj_desc->field.resource_buffer =
0450                 second_desc->buffer.pointer;
0451             obj_desc->field.resource_length =
0452                 (u16)second_desc->buffer.length;
0453         } else if (info->resource_buffer) {
0454             obj_desc->field.resource_buffer = info->resource_buffer;
0455             obj_desc->field.resource_length = info->resource_length;
0456         }
0457
0458         obj_desc->field.pin_number_index = info->pin_number_index;
0459
0460         /* Allow full data read from EC address space */
0461
0462         if ((obj_desc->field.region_obj->region.space_id ==
0463              ACPI_ADR_SPACE_EC)
0464             && (obj_desc->common_field.bit_length > 8)) {
0465             access_byte_width =
0466                 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.
0467                             bit_length);
0468
0469             /* Maximum byte width supported is 255 */
0470
0471             if (access_byte_width < 256) {
0472                 obj_desc->common_field.access_byte_width =
0473                     (u8)access_byte_width;
0474             }
0475         }
0476         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
0477                   "RegionField: BitOff %X, Off %X, Gran %X, Region %p\n",
0478                   obj_desc->field.start_field_bit_offset,
0479                   obj_desc->field.base_byte_offset,
0480                   obj_desc->field.access_byte_width,
0481                   obj_desc->field.region_obj));
0482         break;
0483
0484     case ACPI_TYPE_LOCAL_BANK_FIELD:
0485
0486         obj_desc->bank_field.value = info->bank_value;
0487         obj_desc->bank_field.region_obj =
0488             acpi_ns_get_attached_object(info->region_node);
0489         obj_desc->bank_field.bank_obj =
0490             acpi_ns_get_attached_object(info->register_node);
0491
0492         /* An additional reference for the attached objects */
0493
0494         acpi_ut_add_reference(obj_desc->bank_field.region_obj);
0495         acpi_ut_add_reference(obj_desc->bank_field.bank_obj);
0496
0497         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
0498                   "Bank Field: BitOff %X, Off %X, Gran %X, Region %p, BankReg %p\n",
0499                   obj_desc->bank_field.start_field_bit_offset,
0500                   obj_desc->bank_field.base_byte_offset,
0501                   obj_desc->field.access_byte_width,
0502                   obj_desc->bank_field.region_obj,
0503                   obj_desc->bank_field.bank_obj));
0504
0505         /*
0506          * Remember location in AML stream of the field unit
0507          * opcode and operands -- since the bank_value
0508          * operands must be evaluated.
0509          */
0510         second_desc = obj_desc->common.next_object;
0511         second_desc->extra.aml_start =
0512             ACPI_CAST_PTR(union acpi_parse_object,
0513                   info->data_register_node)->named.data;
0514         second_desc->extra.aml_length =
0515             ACPI_CAST_PTR(union acpi_parse_object,
0516                   info->data_register_node)->named.length;
0517
0518         break;
0519
0520     case ACPI_TYPE_LOCAL_INDEX_FIELD:
0521
0522         /* Get the Index and Data registers */
0523
0524         obj_desc->index_field.index_obj =
0525             acpi_ns_get_attached_object(info->register_node);
0526         obj_desc->index_field.data_obj =
0527             acpi_ns_get_attached_object(info->data_register_node);
0528
0529         if (!obj_desc->index_field.data_obj
0530             || !obj_desc->index_field.index_obj) {
0531             ACPI_ERROR((AE_INFO,
0532                     "Null Index Object during field prep"));
0533             acpi_ut_delete_object_desc(obj_desc);
0534             return_ACPI_STATUS(AE_AML_INTERNAL);
0535         }
0536
0537         /* An additional reference for the attached objects */
0538
0539         acpi_ut_add_reference(obj_desc->index_field.data_obj);
0540         acpi_ut_add_reference(obj_desc->index_field.index_obj);
0541
0542         /*
0543          * April 2006: Changed to match MS behavior
0544          *
0545          * The value written to the Index register is the byte offset of the
0546          * target field in units of the granularity of the index_field
0547          *
0548          * Previously, the value was calculated as an index in terms of the
0549          * width of the Data register, as below:
0550          *
0551          *      obj_desc->index_field.Value = (u32)
0552          *          (Info->field_bit_position / ACPI_MUL_8 (
0553          *              obj_desc->Field.access_byte_width));
0554          *
0555          * February 2006: Tried value as a byte offset:
0556          *      obj_desc->index_field.Value = (u32)
0557          *          ACPI_DIV_8 (Info->field_bit_position);
0558          */
0559         obj_desc->index_field.value =
0560             (u32) ACPI_ROUND_DOWN(ACPI_DIV_8(info->field_bit_position),
0561                       obj_desc->index_field.
0562                       access_byte_width);
0563
0564         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
0565                   "IndexField: BitOff %X, Off %X, Value %X, "
0566                   "Gran %X, Index %p, Data %p\n",
0567                   obj_desc->index_field.start_field_bit_offset,
0568                   obj_desc->index_field.base_byte_offset,
0569                   obj_desc->index_field.value,
0570                   obj_desc->field.access_byte_width,
0571                   obj_desc->index_field.index_obj,
0572                   obj_desc->index_field.data_obj));
0573         break;
0574
0575     default:
0576
0577         /* No other types should get here */
0578
0579         break;
0580     }
0581
0582     /*
0583      * Store the constructed descriptor (obj_desc) into the parent Node,
0584      * preserving the current type of that named_obj.
0585      */
0586     status =
0587         acpi_ns_attach_object(info->field_node, obj_desc,
0588                   acpi_ns_get_type(info->field_node));
0589
0590     ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
0591               "Set NamedObj %p [%4.4s], ObjDesc %p\n",
0592               info->field_node,
0593               acpi_ut_get_node_name(info->field_node), obj_desc));
0594
0595     /* Remove local reference to the object */
0596
0597     acpi_ut_remove_reference(obj_desc);
0598     return_ACPI_STATUS(status);
0599 }