in acpica/exprep.c [378:599]
acpi_status acpi_ex_prep_field_value(struct acpi_create_field_info *info)
{
union acpi_operand_object *obj_desc;
union acpi_operand_object *second_desc = NULL;
acpi_status status;
u32 access_byte_width;
u32 type;
ACPI_FUNCTION_TRACE(ex_prep_field_value);
/* Parameter validation */
if (info->field_type != ACPI_TYPE_LOCAL_INDEX_FIELD) {
if (!info->region_node) {
ACPI_ERROR((AE_INFO, "Null RegionNode"));
return_ACPI_STATUS(AE_AML_NO_OPERAND);
}
type = acpi_ns_get_type(info->region_node);
if (type != ACPI_TYPE_REGION) {
ACPI_ERROR((AE_INFO,
"Needed Region, found type 0x%X (%s)", type,
acpi_ut_get_type_name(type)));
return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
}
}
/* Allocate a new field object */
obj_desc = acpi_ut_create_internal_object(info->field_type);
if (!obj_desc) {
return_ACPI_STATUS(AE_NO_MEMORY);
}
/* Initialize areas of the object that are common to all fields */
obj_desc->common_field.node = info->field_node;
status = acpi_ex_prep_common_field_object(obj_desc,
info->field_flags,
info->attribute,
info->field_bit_position,
info->field_bit_length);
if (ACPI_FAILURE(status)) {
acpi_ut_delete_object_desc(obj_desc);
return_ACPI_STATUS(status);
}
/* Initialize areas of the object that are specific to the field type */
switch (info->field_type) {
case ACPI_TYPE_LOCAL_REGION_FIELD:
obj_desc->field.region_obj =
acpi_ns_get_attached_object(info->region_node);
/* Fields specific to generic_serial_bus fields */
obj_desc->field.access_length = info->access_length;
if (info->connection_node) {
second_desc = info->connection_node->object;
if (!(second_desc->common.flags & AOPOBJ_DATA_VALID)) {
status =
acpi_ds_get_buffer_arguments(second_desc);
if (ACPI_FAILURE(status)) {
acpi_ut_delete_object_desc(obj_desc);
return_ACPI_STATUS(status);
}
}
obj_desc->field.resource_buffer =
second_desc->buffer.pointer;
obj_desc->field.resource_length =
(u16)second_desc->buffer.length;
} else if (info->resource_buffer) {
obj_desc->field.resource_buffer = info->resource_buffer;
obj_desc->field.resource_length = info->resource_length;
}
obj_desc->field.pin_number_index = info->pin_number_index;
/* Allow full data read from EC address space */
if ((obj_desc->field.region_obj->region.space_id ==
ACPI_ADR_SPACE_EC)
&& (obj_desc->common_field.bit_length > 8)) {
access_byte_width =
ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.
bit_length);
/* Maximum byte width supported is 255 */
if (access_byte_width < 256) {
obj_desc->common_field.access_byte_width =
(u8)access_byte_width;
}
}
ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
"RegionField: BitOff %X, Off %X, Gran %X, Region %p\n",
obj_desc->field.start_field_bit_offset,
obj_desc->field.base_byte_offset,
obj_desc->field.access_byte_width,
obj_desc->field.region_obj));
break;
case ACPI_TYPE_LOCAL_BANK_FIELD:
obj_desc->bank_field.value = info->bank_value;
obj_desc->bank_field.region_obj =
acpi_ns_get_attached_object(info->region_node);
obj_desc->bank_field.bank_obj =
acpi_ns_get_attached_object(info->register_node);
/* An additional reference for the attached objects */
acpi_ut_add_reference(obj_desc->bank_field.region_obj);
acpi_ut_add_reference(obj_desc->bank_field.bank_obj);
ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
"Bank Field: BitOff %X, Off %X, Gran %X, Region %p, BankReg %p\n",
obj_desc->bank_field.start_field_bit_offset,
obj_desc->bank_field.base_byte_offset,
obj_desc->field.access_byte_width,
obj_desc->bank_field.region_obj,
obj_desc->bank_field.bank_obj));
/*
* Remember location in AML stream of the field unit
* opcode and operands -- since the bank_value
* operands must be evaluated.
*/
second_desc = obj_desc->common.next_object;
second_desc->extra.aml_start =
ACPI_CAST_PTR(union acpi_parse_object,
info->data_register_node)->named.data;
second_desc->extra.aml_length =
ACPI_CAST_PTR(union acpi_parse_object,
info->data_register_node)->named.length;
break;
case ACPI_TYPE_LOCAL_INDEX_FIELD:
/* Get the Index and Data registers */
obj_desc->index_field.index_obj =
acpi_ns_get_attached_object(info->register_node);
obj_desc->index_field.data_obj =
acpi_ns_get_attached_object(info->data_register_node);
if (!obj_desc->index_field.data_obj
|| !obj_desc->index_field.index_obj) {
ACPI_ERROR((AE_INFO,
"Null Index Object during field prep"));
acpi_ut_delete_object_desc(obj_desc);
return_ACPI_STATUS(AE_AML_INTERNAL);
}
/* An additional reference for the attached objects */
acpi_ut_add_reference(obj_desc->index_field.data_obj);
acpi_ut_add_reference(obj_desc->index_field.index_obj);
/*
* April 2006: Changed to match MS behavior
*
* The value written to the Index register is the byte offset of the
* target field in units of the granularity of the index_field
*
* Previously, the value was calculated as an index in terms of the
* width of the Data register, as below:
*
* obj_desc->index_field.Value = (u32)
* (Info->field_bit_position / ACPI_MUL_8 (
* obj_desc->Field.access_byte_width));
*
* February 2006: Tried value as a byte offset:
* obj_desc->index_field.Value = (u32)
* ACPI_DIV_8 (Info->field_bit_position);
*/
obj_desc->index_field.value =
(u32) ACPI_ROUND_DOWN(ACPI_DIV_8(info->field_bit_position),
obj_desc->index_field.
access_byte_width);
ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
"IndexField: BitOff %X, Off %X, Value %X, "
"Gran %X, Index %p, Data %p\n",
obj_desc->index_field.start_field_bit_offset,
obj_desc->index_field.base_byte_offset,
obj_desc->index_field.value,
obj_desc->field.access_byte_width,
obj_desc->index_field.index_obj,
obj_desc->index_field.data_obj));
break;
default:
/* No other types should get here */
break;
}
/*
* Store the constructed descriptor (obj_desc) into the parent Node,
* preserving the current type of that named_obj.
*/
status =
acpi_ns_attach_object(info->field_node, obj_desc,
acpi_ns_get_type(info->field_node));
ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
"Set NamedObj %p [%4.4s], ObjDesc %p\n",
info->field_node,
acpi_ut_get_node_name(info->field_node), obj_desc));
/* Remove local reference to the object */
acpi_ut_remove_reference(obj_desc);
return_ACPI_STATUS(status);
}