uio: Support 2^MINOR_BITS minors
authorEric W. Biederman <ebiederm@aristanetworks.com>
Tue, 14 Sep 2010 18:38:06 +0000 (11:38 -0700)
committerGreg Kroah-Hartman <gregkh@suse.de>
Fri, 22 Oct 2010 17:16:43 +0000 (10:16 -0700)
commit91960a46c658b719c03fba80f1c60a96393bbcfd
treeffa50ea8eeddd9105dff834877ed594cf71ce697
parent6427a7655afd7f07dfa83736defd1d94656c83e5
uio: Support 2^MINOR_BITS minors

register_chrdev limits uio devices to 256 minor numbers which causes
problems on one system I have with 384+ uio devices.  So instead set
UIO_MAX_DEVICES to the maximum number of minors and use
alloc_chrdev_region to reserve the uio minors.

The final result is that the code works the same but the uio driver now
supports any minor the idr allocator comes up with.

Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Hans J. Koch <hjk@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/uio/uio.c