NAME

     MAJOR, MINOR, MKDEV - macros to manipulate device
     major/minor numbers

SYNOPSIS

     #include <linux/fs.h>

     #define MAJOR(dev))
     #define MINOR(dev))
     #define MKDEV(major, minor))

DESCRIPTION

     The MAJOR and MINOR macros extract from a device id (of type
     dev_t)  the  major and minor numbers respectively. It is the
     combined device number that  is  found  in  the  struct~file
     structure.

     The MKDEV macro assembles a device number from the  supplied
     major and minor numbers.

RETURN VALUE

     Describe the  return  values.  Enumerate  all  the  distinct
     values and all the ranges.

AVAILABILITY

     Linux 0.0+

     In later kernels (Linux 2.1 and  later)  there  is  movement
     towards using 64bit device numbers. Although it is generally
     a good idea to not presume to know how  device  numbers  are
     constructed,  it  is during this period of transition funda-
     mentally important that you  ONLY  use  these  functions  to
     manipulate device numbers.

SEE ALSO

     mknod(1)

     Also list some source files for the  kernel  that  implement
     the functions of the page.

AUTHOR

     Stephen Williams <steve@icarus.com>

BUGS

     These are macros, so parameters may  be  evaluated  multiple
     times.