functions are selfcontained (ie. they touch only isa_dma.c static variables
and hardware) so a private lock is sufficient to prevent races. This changes
only i386/amd64 while there are also isa_dma functions for ia64/sparc64.
Sparc64 are ones empty stubs and ia64 ones are unused as ia64 does not
have isa (says marcel).
This patch removes explicit locking of Giant from a few drivers (there
are some that requires this but lack ones - this patch fixes this) and
also removes the need for implicit locking of Giant from attach routines
where it's provided by newbus.
Approved by: ed (mentor, implicit)
Reviewed by: jhb, attilio (glanced by)
Tested by: Giovanni Trematerra <giovanni.trematerra gmail com>
IA64 clue: marcel
Even though we got rid of device major numbers some time ago, device
drivers still need to provide unique device minor numbers to make_dev().
These numbers are only used inside the kernel. They are not related to
device major and minor numbers which are visible in devfs. These are
actually based on the inode number of the device.
It would eventually be nice to remove minor numbers entirely, but we
don't want to be too agressive here.
Because the 8-15 bits of the device number field (si_drv0) are still
reserved for the major number, there is no 1:1 mapping of the device
minor and unit numbers. Because this is now unused, remove the
restrictions on these numbers.
The MAXMAJOR definition was actually used for two purposes. It was used
to convert both the userspace and kernelspace device numbers to their
major/minor pair, which is why it is now named UMINORMASK.
minor2unit() and unit2minor() have now become useless. Both minor() and
dev2unit() now serve the same purpose. We should eventually remove some
of them, at least turning them into macro's. If devfs would become
completely minor number unaware, we could consider using si_drv0 directly,
just like si_drv1 and si_drv2.
Approved by: philip (mentor)
This driver implements "unaddressed listen only mode", which is what
printers and plotters commonly do on GP-IB busses.
This means that you can capture print/plot like output from your
instruments by configuring them as necessary (good luck!) and
cat -u /dev/gpib0l > /tmp/somefile
Since there is no way to know when no more output is comming you
will have to ctrl-C the cat process when it is done (that is why
the -u is important).
