Add helpers for io operations, so that we can eliminate huge
amount of supporting code. It is now centralized in those
helpers and used values are precomputed in the init phase.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>