Thanks everyone for the information.
I am trying to implement a software callable interrupt so it can be called
by user-mode code to indicate that certain events have occurred (it's part
of an instrumentation package I'm working on). I don't want to add a syscall
since there is other code on the system that is already monitoring int 0x80,
and I don't want these instrumentation interrupts to be visible by the code
already monitoring syscalls.
Unless someone has a more specific suggestion, I will look into
request_irq(). However, it appears that will require creation of a new
device (so I can pass the devname and dev_id params), which I'd rather not
do, since I'd rather that the instrumentation impacts/changes the system as
little as possible.