acpi_status
acpi_ex_insert_into_field (
union acpi_operand_object *obj_desc,
void *buffer,
u32 buffer_length)
{
acpi_status status;
acpi_integer mask;
acpi_integer merged_datum;
acpi_integer raw_datum = 0;
u32 field_offset = 0;
u32 buffer_offset = 0;
u32 buffer_tail_bits;
u32 datum_count;
u32 field_datum_count;
u32 i;
ACPI_FUNCTION_TRACE ("ex_insert_into_field");
/* Validate input buffer */
if (buffer_length < ACPI_ROUND_BITS_UP_TO_BYTES (
obj_desc->common_field.bit_length)) {
ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
"Field size %X (bits) is too large for buffer (%X)\n",
obj_desc->common_field.bit_length, buffer_length));
return_ACPI_STATUS (AE_BUFFER_OVERFLOW);
}
/* Compute the number of datums (access width data items) */
mask = ACPI_MASK_BITS_BELOW (obj_desc->common_field.start_field_bit_offset);
datum_count = ACPI_ROUND_UP_TO (obj_desc->common_field.bit_length,
obj_desc->common_field.access_bit_width);
field_datum_count = ACPI_ROUND_UP_TO (obj_desc->common_field.bit_length +
obj_desc->common_field.start_field_bit_offset,
obj_desc->common_field.access_bit_width);
/* Get initial Datum from the input buffer */
ACPI_MEMCPY (&raw_datum, buffer,
ACPI_MIN(obj_desc->common_field.access_byte_width,
buffer_length - buffer_offset));
merged_datum = raw_datum << obj_desc->common_field.start_field_bit_offset;
/* Write the entire field */
for (i = 1; i < field_datum_count; i++) {
/* Write merged datum to the target field */
merged_datum &= mask;
status = acpi_ex_write_with_update_rule (obj_desc, mask, merged_datum, field_offset);
if (ACPI_FAILURE (status)) {
return_ACPI_STATUS (status);
}
/* Start new output datum by merging with previous input datum */
field_offset += obj_desc->common_field.access_byte_width;
merged_datum = raw_datum >>
(obj_desc->common_field.access_bit_width - obj_desc->common_field.start_field_bit_offset);
mask = ACPI_INTEGER_MAX;
if (i == datum_count) {
break;
}
/* Get the next input datum from the buffer */
buffer_offset += obj_desc->common_field.access_byte_width;
ACPI_MEMCPY (&raw_datum, ((char *) buffer) + buffer_offset,
ACPI_MIN(obj_desc->common_field.access_byte_width,
buffer_length - buffer_offset));
merged_datum |= raw_datum << obj_desc->common_field.start_field_bit_offset;
}
/* Mask off any extra bits in the last datum */
buffer_tail_bits = (obj_desc->common_field.bit_length +
obj_desc->common_field.start_field_bit_offset) % obj_desc->common_field.access_bit_width;
if (buffer_tail_bits) {
mask &= ACPI_MASK_BITS_ABOVE (buffer_tail_bits);
}
/* Write the last datum to the field */
merged_datum &= mask;
status = acpi_ex_write_with_update_rule (obj_desc, mask, merged_datum, field_offset);
return_ACPI_STATUS (status);
}
acpi_status
acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
void *buffer, u32 buffer_length)
{
void *new_buffer;
acpi_status status;
u64 mask;
u64 width_mask;
u64 merged_datum;
u64 raw_datum = 0;
u32 field_offset = 0;
u32 buffer_offset = 0;
u32 buffer_tail_bits;
u32 datum_count;
u32 field_datum_count;
u32 access_bit_width;
u32 required_length;
u32 i;
ACPI_FUNCTION_TRACE(ex_insert_into_field);
/* Validate input buffer */
new_buffer = NULL;
required_length =
ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
/*
* We must have a buffer that is at least as long as the field
* we are writing to. This is because individual fields are
* indivisible and partial writes are not supported -- as per
* the ACPI specification.
*/
if (buffer_length < required_length) {
/* We need to create a new buffer */
new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
if (!new_buffer) {
return_ACPI_STATUS(AE_NO_MEMORY);
}
/*
* Copy the original data to the new buffer, starting
* at Byte zero. All unused (upper) bytes of the
* buffer will be 0.
*/
ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length);
buffer = new_buffer;
buffer_length = required_length;
}
/* TBD: Move to common setup code */
/* Algo is limited to sizeof(u64), so cut the access_byte_width */
if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
obj_desc->common_field.access_byte_width = sizeof(u64);
}
access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
/*
* Create the bitmasks used for bit insertion.
* Note: This if/else is used to bypass compiler differences with the
* shift operator
*/
if (access_bit_width == ACPI_INTEGER_BIT_SIZE) {
width_mask = ACPI_UINT64_MAX;
} else {
width_mask = ACPI_MASK_BITS_ABOVE(access_bit_width);
}
mask = width_mask &
ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
/* Compute the number of datums (access width data items) */
datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
access_bit_width);
field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
obj_desc->common_field.
start_field_bit_offset,
access_bit_width);
/* Get initial Datum from the input buffer */
ACPI_MEMCPY(&raw_datum, buffer,
ACPI_MIN(obj_desc->common_field.access_byte_width,
buffer_length - buffer_offset));
merged_datum =
raw_datum << obj_desc->common_field.start_field_bit_offset;
/* Write the entire field */
for (i = 1; i < field_datum_count; i++) {
/* Write merged datum to the target field */
merged_datum &= mask;
status = acpi_ex_write_with_update_rule(obj_desc, mask,
merged_datum,
field_offset);
if (ACPI_FAILURE(status)) {
goto exit;
}
field_offset += obj_desc->common_field.access_byte_width;
/*
* Start new output datum by merging with previous input datum
* if necessary.
*
* Note: Before the shift, check if the shift value will be larger than
* the integer size. If so, there is no need to perform the operation.
* This avoids the differences in behavior between different compilers
* concerning shift values larger than the target data width.
*/
if ((access_bit_width -
obj_desc->common_field.start_field_bit_offset) <
ACPI_INTEGER_BIT_SIZE) {
merged_datum =
raw_datum >> (access_bit_width -
obj_desc->common_field.
start_field_bit_offset);
} else {
acpi_status
acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
void *buffer, u32 buffer_length)
{
acpi_status status;
acpi_integer mask;
acpi_integer width_mask;
acpi_integer merged_datum;
acpi_integer raw_datum = 0;
u32 field_offset = 0;
u32 buffer_offset = 0;
u32 buffer_tail_bits;
u32 datum_count;
u32 field_datum_count;
u32 i;
ACPI_FUNCTION_TRACE(ex_insert_into_field);
/* Validate input buffer */
if (buffer_length <
ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
ACPI_ERROR((AE_INFO,
"Field size %X (bits) is too large for buffer (%X)",
obj_desc->common_field.bit_length, buffer_length));
return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
}
/*
* Create the bitmasks used for bit insertion.
* Note: This if/else is used to bypass compiler differences with the
* shift operator
*/
if (obj_desc->common_field.access_bit_width == ACPI_INTEGER_BIT_SIZE) {
width_mask = ACPI_INTEGER_MAX;
} else {
width_mask =
ACPI_MASK_BITS_ABOVE(obj_desc->common_field.
access_bit_width);
}
mask = width_mask &
ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
/* Compute the number of datums (access width data items) */
datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
obj_desc->common_field.access_bit_width);
field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
obj_desc->common_field.
start_field_bit_offset,
obj_desc->common_field.
access_bit_width);
/* Get initial Datum from the input buffer */
ACPI_MEMCPY(&raw_datum, buffer,
ACPI_MIN(obj_desc->common_field.access_byte_width,
buffer_length - buffer_offset));
merged_datum =
raw_datum << obj_desc->common_field.start_field_bit_offset;
/* Write the entire field */
for (i = 1; i < field_datum_count; i++) {
/* Write merged datum to the target field */
merged_datum &= mask;
status = acpi_ex_write_with_update_rule(obj_desc, mask,
merged_datum,
field_offset);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
field_offset += obj_desc->common_field.access_byte_width;
/*
* Start new output datum by merging with previous input datum
* if necessary.
*
* Note: Before the shift, check if the shift value will be larger than
* the integer size. If so, there is no need to perform the operation.
* This avoids the differences in behavior between different compilers
* concerning shift values larger than the target data width.
*/
if ((obj_desc->common_field.access_bit_width -
obj_desc->common_field.start_field_bit_offset) <
ACPI_INTEGER_BIT_SIZE) {
merged_datum =
raw_datum >> (obj_desc->common_field.
access_bit_width -
obj_desc->common_field.
start_field_bit_offset);
} else {
