acpi_status
acpi_ex_prep_common_field_object(union acpi_operand_object *obj_desc,
u8 field_flags,
u8 field_attribute,
u32 field_bit_position, u32 field_bit_length)
{
u32 access_bit_width;
u32 byte_alignment;
u32 nearest_byte_address;
ACPI_FUNCTION_TRACE(ex_prep_common_field_object);
obj_desc->common_field.field_flags = field_flags;
obj_desc->common_field.attribute = field_attribute;
obj_desc->common_field.bit_length = field_bit_length;
access_bit_width = acpi_ex_decode_field_access(obj_desc, field_flags,
&byte_alignment);
if (!access_bit_width) {
return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
}
obj_desc->common_field.access_byte_width = (u8)
ACPI_DIV_8(access_bit_width);
obj_desc->common_field.access_bit_width = (u8) access_bit_width;
nearest_byte_address =
ACPI_ROUND_BITS_DOWN_TO_BYTES(field_bit_position);
obj_desc->common_field.base_byte_offset = (u32)
ACPI_ROUND_DOWN(nearest_byte_address, byte_alignment);
obj_desc->common_field.start_field_bit_offset = (u8)
(field_bit_position -
ACPI_MUL_8(obj_desc->common_field.base_byte_offset));
if ((obj_desc->common_field.start_field_bit_offset +
field_bit_length) <= (u16) access_bit_width) {
obj_desc->common.flags |= AOPOBJ_SINGLE_DATUM;
}
return_ACPI_STATUS(AE_OK);
}
acpi_status
acpi_ex_prep_common_field_object(union acpi_operand_object *obj_desc,
u8 field_flags,
u8 field_attribute,
u32 field_bit_position, u32 field_bit_length)
{
u32 access_bit_width;
u32 byte_alignment;
u32 nearest_byte_address;
ACPI_FUNCTION_TRACE(ex_prep_common_field_object);
/*
* Note: the structure being initialized is the
* ACPI_COMMON_FIELD_INFO; No structure fields outside of the common
* area are initialized by this procedure.
*/
obj_desc->common_field.field_flags = field_flags;
obj_desc->common_field.attribute = field_attribute;
obj_desc->common_field.bit_length = field_bit_length;
/*
* Decode the access type so we can compute offsets. The access type gives
* two pieces of information - the width of each field access and the
* necessary byte_alignment (address granularity) of the access.
*
* For any_acc, the access_bit_width is the largest width that is both
* necessary and possible in an attempt to access the whole field in one
* I/O operation. However, for any_acc, the byte_alignment is always one
* byte.
*
* For all Buffer Fields, the byte_alignment is always one byte.
*
* For all other access types (Byte, Word, Dword, Qword), the Bitwidth is
* the same (equivalent) as the byte_alignment.
*/
access_bit_width = acpi_ex_decode_field_access(obj_desc, field_flags,
&byte_alignment);
if (!access_bit_width) {
return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
}
/* Setup width (access granularity) fields */
obj_desc->common_field.access_byte_width = (u8)
ACPI_DIV_8(access_bit_width); /* 1, 2, 4, 8 */
obj_desc->common_field.access_bit_width = (u8) access_bit_width;
/*
* base_byte_offset is the address of the start of the field within the
* region. It is the byte address of the first *datum* (field-width data
* unit) of the field. (i.e., the first datum that contains at least the
* first *bit* of the field.)
*
* Note: byte_alignment is always either equal to the access_bit_width or 8
* (Byte access), and it defines the addressing granularity of the parent
* region or buffer.
*/
nearest_byte_address =
ACPI_ROUND_BITS_DOWN_TO_BYTES(field_bit_position);
obj_desc->common_field.base_byte_offset = (u32)
ACPI_ROUND_DOWN(nearest_byte_address, byte_alignment);
/*
* start_field_bit_offset is the offset of the first bit of the field within
* a field datum.
*/
obj_desc->common_field.start_field_bit_offset = (u8)
(field_bit_position -
ACPI_MUL_8(obj_desc->common_field.base_byte_offset));
return_ACPI_STATUS(AE_OK);
}
acpi_status
acpi_ex_prep_common_field_object (
union acpi_operand_object *obj_desc,
u8 field_flags,
u8 field_attribute,
u32 field_bit_position,
u32 field_bit_length)
{
u32 access_bit_width;
u32 byte_alignment;
u32 nearest_byte_address;
ACPI_FUNCTION_TRACE ("ex_prep_common_field_object");
/*
* Note: the structure being initialized is the
* ACPI_COMMON_FIELD_INFO; No structure fields outside of the common
* area are initialized by this procedure.
*/
obj_desc->common_field.field_flags = field_flags;
obj_desc->common_field.attribute = field_attribute;
obj_desc->common_field.bit_length = field_bit_length;
/*
* Decode the access type so we can compute offsets. The access type gives
* two pieces of information - the width of each field access and the
* necessary byte_alignment (address granularity) of the access.
*
* For any_acc, the access_bit_width is the largest width that is both
* necessary and possible in an attempt to access the whole field in one
* I/O operation. However, for any_acc, the byte_alignment is always one
* byte.
*
* For all Buffer Fields, the byte_alignment is always one byte.
*
* For all other access types (Byte, Word, Dword, Qword), the Bitwidth is
* the same (equivalent) as the byte_alignment.
*/
access_bit_width = acpi_ex_decode_field_access (obj_desc, field_flags,
&byte_alignment);
if (!access_bit_width) {
return_ACPI_STATUS (AE_AML_OPERAND_VALUE);
}
/* Setup width (access granularity) fields */
obj_desc->common_field.access_byte_width = (u8)
ACPI_DIV_8 (access_bit_width); /* 1, 2, 4, 8 */
/*
* base_byte_offset is the address of the start of the field within the
* region. It is the byte address of the first *datum* (field-width data
* unit) of the field. (i.e., the first datum that contains at least the
* first *bit* of the field.)
*
* Note: byte_alignment is always either equal to the access_bit_width or 8
* (Byte access), and it defines the addressing granularity of the parent
* region or buffer.
*/
nearest_byte_address =
ACPI_ROUND_BITS_DOWN_TO_BYTES (field_bit_position);
obj_desc->common_field.base_byte_offset =
ACPI_ROUND_DOWN (nearest_byte_address, byte_alignment);
/*
* start_field_bit_offset is the offset of the first bit of the field within
* a field datum.
*/
obj_desc->common_field.start_field_bit_offset = (u8)
(field_bit_position - ACPI_MUL_8 (obj_desc->common_field.base_byte_offset));
/*
* Valid bits -- the number of bits that compose a partial datum,
* 1) At the end of the field within the region (arbitrary starting bit
* offset)
* 2) At the end of a buffer used to contain the field (starting offset
* always zero)
*/
obj_desc->common_field.end_field_valid_bits = (u8)
((obj_desc->common_field.start_field_bit_offset + field_bit_length) %
access_bit_width);
/* start_buffer_bit_offset always = 0 */
obj_desc->common_field.end_buffer_valid_bits = (u8)
(field_bit_length % access_bit_width);
/*
* datum_valid_bits is the number of valid field bits in the first
* field datum.
*/
obj_desc->common_field.datum_valid_bits = (u8)
(access_bit_width - obj_desc->common_field.start_field_bit_offset);
/*
* Does the entire field fit within a single field access element? (datum)
* (i.e., without crossing a datum boundary)
*/
if ((obj_desc->common_field.start_field_bit_offset + field_bit_length) <=
(u16) access_bit_width) {
obj_desc->common.flags |= AOPOBJ_SINGLE_DATUM;
}
return_ACPI_STATUS (AE_OK);
}