This is a library-like set of functions, but they are not in the kernel,
as far as I know, so let's offer them here. We will use them in the
vmalloc buffer, in place of the circular buffer we have now, and for
allocating minor device numbers.
Signed-off-by: Alessandro Rubini <rubini@gnudd.com>
Acked-by: Federico Vaga <federico.vaga@gmail.com>