upper_32_bits(9) centos man page | unix.com

UPPER_32_BITS(9)						   Driver Basics						  UPPER_32_BITS(9)

NAME
       upper_32_bits - return bits 32-63 of a number

SYNOPSIS
       upper_32_bits(n);

ARGUMENTS
       n
	   the number we're accessing

DESCRIPTION
       A basic shift-right of a 64- or 32-bit quantity. Use this to suppress the "right shift count >= width of type" warning when that quantity
       is 32-bits.

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014							  UPPER_32_BITS(9)