// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
*
* Module Name: exfield - AML execution - field_unit read/write
*
* Copyright (C) 2000 - 2025, Intel Corp.
*
*****************************************************************************/
#include <acpi/acpi.h>
#include "accommon.h"
#include "acdispat.h"
#include "acinterp.h"
#include "amlcode.h"
#define _COMPONENT ACPI_EXECUTER
ACPI_MODULE_NAME(
"exfield")
/*
* This table maps the various Attrib protocols to the byte transfer
* length. Used for the generic serial bus.
*/
#define ACPI_INVALID_PROTOCOL_ID 0x80
#define ACPI_MAX_PROTOCOL_ID 0x0F
static const u8 acpi_protocol_lengths[] = {
ACPI_INVALID_PROTOCOL_ID,
/* 0 - reserved */
ACPI_INVALID_PROTOCOL_ID,
/* 1 - reserved */
0x00,
/* 2 - ATTRIB_QUICK */
ACPI_INVALID_PROTOCOL_ID,
/* 3 - reserved */
0x01,
/* 4 - ATTRIB_SEND_RECEIVE */
ACPI_INVALID_PROTOCOL_ID,
/* 5 - reserved */
0x01,
/* 6 - ATTRIB_BYTE */
ACPI_INVALID_PROTOCOL_ID,
/* 7 - reserved */
0x02,
/* 8 - ATTRIB_WORD */
ACPI_INVALID_PROTOCOL_ID,
/* 9 - reserved */
0xFF,
/* A - ATTRIB_BLOCK */
0xFF,
/* B - ATTRIB_BYTES */
0x02,
/* C - ATTRIB_PROCESS_CALL */
0xFF,
/* D - ATTRIB_BLOCK_PROCESS_CALL */
0xFF,
/* E - ATTRIB_RAW_BYTES */
0xFF
/* F - ATTRIB_RAW_PROCESS_BYTES */
};
#define PCC_MASTER_SUBSPACE 3
/*
* The following macros determine a given offset is a COMD field.
* According to the specification, generic subspaces (types 0-2) contains a
* 2-byte COMD field at offset 4 and master subspaces (type 3) contains a 4-byte
* COMD field starting at offset 12.
*/
#define GENERIC_SUBSPACE_COMMAND(a) (4 == a || a == 5)
#define MASTER_SUBSPACE_COMMAND(a) (12 <= a && a <= 15)
/*******************************************************************************
*
* FUNCTION: acpi_ex_get_protocol_buffer_length
*
* PARAMETERS: protocol_id - The type of the protocol indicated by region
* field access attributes
* return_length - Where the protocol byte transfer length is
* returned
*
* RETURN: Status and decoded byte transfer length
*
* DESCRIPTION: This routine returns the length of the generic_serial_bus
* protocol bytes
*
******************************************************************************/
acpi_status
acpi_ex_get_protocol_buffer_length(u32 protocol_id, u32 *return_length)
{
if ((protocol_id > ACPI_MAX_PROTOCOL_ID) ||
(acpi_protocol_lengths[protocol_id] == ACPI_INVALID_PROTOCOL_ID)) {
ACPI_ERROR((AE_INFO,
"Invalid Field/AccessAs protocol ID: 0x%4.4X",
protocol_id));
return (AE_AML_PROTOCOL);
}
*return_length = acpi_protocol_lengths[protocol_id];
return (AE_OK);
}
/*******************************************************************************
*
* FUNCTION: acpi_ex_read_data_from_field
*
* PARAMETERS: walk_state - Current execution state
* obj_desc - The named field
* ret_buffer_desc - Where the return data object is stored
*
* RETURN: Status
*
* DESCRIPTION: Read from a named field. Returns either an Integer or a
* Buffer, depending on the size of the field and whether if a
* field is created by the create_field() operator.
*
******************************************************************************/
acpi_status
acpi_ex_read_data_from_field(
struct acpi_walk_state *walk_state,
union acpi_operand_object *obj_desc,
union acpi_operand_object **ret_buffer_desc)
{
acpi_status status;
union acpi_operand_object *buffer_desc;
void *buffer;
u32 buffer_length;
ACPI_FUNCTION_TRACE_PTR(ex_read_data_from_field, obj_desc);
/* Parameter validation */
if (!obj_desc) {
return_ACPI_STATUS(AE_AML_NO_OPERAND);
}
if (!ret_buffer_desc) {
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
if (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD) {
/*
* If the buffer_field arguments have not been previously evaluated,
* evaluate them now and save the results.
*/
if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
status = acpi_ds_get_buffer_field_arguments(obj_desc);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
}
}
else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
(obj_desc->field.region_obj->region.space_id ==
ACPI_ADR_SPACE_SMBUS
|| obj_desc->field.region_obj->region.space_id ==
ACPI_ADR_SPACE_GSBUS
|| obj_desc->field.region_obj->region.space_id ==
ACPI_ADR_SPACE_IPMI
|| obj_desc->field.region_obj->region.space_id ==
ACPI_ADR_SPACE_PLATFORM_RT
|| obj_desc->field.region_obj->region.space_id ==
ACPI_ADR_SPACE_FIXED_HARDWARE)) {
/* SMBus, GSBus, IPMI serial */
status = acpi_ex_read_serial_bus(obj_desc, ret_buffer_desc);
return_ACPI_STATUS(status);
}
/*
* Allocate a buffer for the contents of the field.
*
* If the field is larger than the current integer width, create
* a BUFFER to hold it. Otherwise, use an INTEGER. This allows
* the use of arithmetic operators on the returned value if the
* field size is equal or smaller than an Integer.
*
* However, all buffer fields created by create_field operator needs to
* remain as a buffer to match other AML interpreter implementations.
*
* Note: Field.length is in bits.
*/
buffer_length =
(acpi_size)ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.bit_length);
if (buffer_length > acpi_gbl_integer_byte_width ||
(obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD &&
obj_desc->buffer_field.is_create_field)) {
/* Field is too large for an Integer, create a Buffer instead */
buffer_desc = acpi_ut_create_buffer_object(buffer_length);
if (!buffer_desc) {
return_ACPI_STATUS(AE_NO_MEMORY);
}
buffer = buffer_desc->buffer.pointer;
}
else {
/* Field will fit within an Integer (normal case) */
buffer_desc = acpi_ut_create_integer_object((u64) 0);
if (!buffer_desc) {
return_ACPI_STATUS(AE_NO_MEMORY);
}
buffer_length = acpi_gbl_integer_byte_width;
buffer = &buffer_desc->integer.value;
}
if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
(obj_desc->field.region_obj->region.space_id ==
ACPI_ADR_SPACE_GPIO)) {
/* General Purpose I/O */
status = acpi_ex_read_gpio(obj_desc, buffer);
goto exit;
}
else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
(obj_desc->field.region_obj->region.space_id ==
ACPI_ADR_SPACE_PLATFORM_COMM)) {
/*
* Reading from a PCC field unit does not require the handler because
* it only requires reading from the internal_pcc_buffer.
*/
ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
"PCC FieldRead bits %u\n",
obj_desc->field.bit_length));
memcpy(buffer,
obj_desc->field.region_obj->field.internal_pcc_buffer +
obj_desc->field.base_byte_offset,
(acpi_size)ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.
bit_length));
*ret_buffer_desc = buffer_desc;
return AE_OK;
}
ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
"FieldRead [TO]: Obj %p, Type %X, Buf %p, ByteLen %X\n",
obj_desc, obj_desc->common.type, buffer,
buffer_length));
ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
"FieldRead [FROM]: BitLen %X, BitOff %X, ByteOff %X\n",
obj_desc->common_field.bit_length,
obj_desc->common_field.start_field_bit_offset,
obj_desc->common_field.base_byte_offset));
/* Lock entire transaction if requested */
acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
/* Read from the field */
status = acpi_ex_extract_from_field(obj_desc, buffer, buffer_length);
acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
exit:
if (ACPI_FAILURE(status)) {
acpi_ut_remove_reference(buffer_desc);
}
else {
*ret_buffer_desc = buffer_desc;
}
return_ACPI_STATUS(status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ex_write_data_to_field
*
* PARAMETERS: source_desc - Contains data to write
* obj_desc - The named field
* result_desc - Where the return value is returned, if any
*
* RETURN: Status
*
* DESCRIPTION: Write to a named field
*
******************************************************************************/
acpi_status
acpi_ex_write_data_to_field(
union acpi_operand_object *source_desc,
union acpi_operand_object *obj_desc,
union acpi_operand_object **result_desc)
{
acpi_status status;
u32 buffer_length;
u32 data_length;
void *buffer;
ACPI_FUNCTION_TRACE_PTR(ex_write_data_to_field, obj_desc);
/* Parameter validation */
if (!source_desc || !obj_desc) {
return_ACPI_STATUS(AE_AML_NO_OPERAND);
}
if (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD) {
/*
* If the buffer_field arguments have not been previously evaluated,
* evaluate them now and save the results.
*/
if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
status = acpi_ds_get_buffer_field_arguments(obj_desc);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
}
}
else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
(obj_desc->field.region_obj->region.space_id ==
ACPI_ADR_SPACE_GPIO)) {
/* General Purpose I/O */
status = acpi_ex_write_gpio(source_desc, obj_desc, result_desc);
return_ACPI_STATUS(status);
}
else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
(obj_desc->field.region_obj->region.space_id ==
ACPI_ADR_SPACE_SMBUS
|| obj_desc->field.region_obj->region.space_id ==
ACPI_ADR_SPACE_GSBUS
|| obj_desc->field.region_obj->region.space_id ==
ACPI_ADR_SPACE_IPMI
|| obj_desc->field.region_obj->region.space_id ==
ACPI_ADR_SPACE_PLATFORM_RT
|| obj_desc->field.region_obj->region.space_id ==
ACPI_ADR_SPACE_FIXED_HARDWARE)) {
/* SMBus, GSBus, IPMI serial */
status =
acpi_ex_write_serial_bus(source_desc, obj_desc,
result_desc);
return_ACPI_STATUS(status);
}
else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
(obj_desc->field.region_obj->region.space_id ==
ACPI_ADR_SPACE_PLATFORM_COMM)) {
/*
* According to the spec a write to the COMD field will invoke the
* region handler. Otherwise, write to the pcc_internal buffer. This
* implementation will use the offsets specified rather than the name
* of the field. This is considered safer because some firmware tools
* are known to obfiscate named objects.
*/
data_length =
(acpi_size)ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.
bit_length);
memcpy(obj_desc->field.region_obj->field.internal_pcc_buffer +
obj_desc->field.base_byte_offset,
source_desc->buffer.pointer, data_length);
if (MASTER_SUBSPACE_COMMAND(obj_desc->field.base_byte_offset)) {
/* Perform the write */
ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
"PCC COMD field has been written. Invoking PCC handler now.\n"));
status =
acpi_ex_access_region(obj_desc, 0,
(u64 *)obj_desc->field.
region_obj->field.
internal_pcc_buffer,
ACPI_WRITE);
return_ACPI_STATUS(status);
}
return (AE_OK);
}
/* Get a pointer to the data to be written */
switch (source_desc->common.type) {
case ACPI_TYPE_INTEGER:
buffer = &source_desc->integer.value;
buffer_length =
sizeof(source_desc->integer.value);
break;
case ACPI_TYPE_BUFFER:
buffer = source_desc->buffer.pointer;
buffer_length = source_desc->buffer.length;
break;
case ACPI_TYPE_STRING:
buffer = source_desc->string.pointer;
buffer_length = source_desc->string.length;
break;
default:
return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
}
ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
"FieldWrite [FROM]: Obj %p (%s:%X), Buf %p, ByteLen %X\n",
source_desc,
acpi_ut_get_type_name(source_desc->common.type),
source_desc->common.type, buffer, buffer_length));
ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
"FieldWrite [TO]: Obj %p (%s:%X), BitLen %X, BitOff %X, ByteOff %X\n",
obj_desc,
acpi_ut_get_type_name(obj_desc->common.type),
obj_desc->common.type,
obj_desc->common_field.bit_length,
obj_desc->common_field.start_field_bit_offset,
obj_desc->common_field.base_byte_offset));
/* Lock entire transaction if requested */
acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
/* Write to the field */
status = acpi_ex_insert_into_field(obj_desc, buffer, buffer_length);
acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
return_ACPI_STATUS(status);
}
