ACPI_MASK_BITS_ABOVE
#define ACPI_MASK_BITS_ABOVE_32(width) ((u32) ACPI_MASK_BITS_ABOVE(width))
ACPI_MASK_BITS_ABOVE(width))
buffer[byte_length - 1] = ACPI_MASK_BITS_ABOVE(extra_bits);
merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);