suse man page for atomic_add_unless

ATOMIC_ADD_UNLESS(9)						   Driver Basics					      ATOMIC_ADD_UNLESS(9)

NAME
       atomic_add_unless - add unless the number is already a given value

SYNOPSIS
       int atomic_add_unless(atomic_t * v, int a, int u);

ARGUMENTS
       v
	   pointer of type atomic_t

       a
	   the amount to add to v...

       u
	   ...unless v is equal to u.

DESCRIPTION
       Atomically adds a to v, so long as v was not already u. Returns non-zero if v was not u, and zero otherwise.

COPYRIGHT
Kernel Hackers Manual 2.6.					     July 2010						      ATOMIC_ADD_UNLESS(9)