genirq: Provide disable_hardirq()

For things like netpoll there is a need to disable an interrupt from
atomic context. Currently netpoll uses disable_irq() which will
sleep-wait on threaded handlers and thus forced_irqthreads breaks
things.

Provide disable_hardirq(), which uses synchronize_hardirq() to only wait
for active hardirq handlers; also change synchronize_hardirq() to
return the status of threaded handlers.

This will allow one to try-disable an interrupt from atomic context, or
in case of request_threaded_irq() to only wait for the hardirq part.

Suggested-by: Sabrina Dubroca <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: David Miller <[email protected]>
Cc: Eyal Perry <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Quentin Lambert <[email protected]>
Cc: Randy Dunlap <[email protected]>
Cc: Russell King <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
[ Fixed typos and such. ]
Signed-off-by: Ingo Molnar <[email protected]>

0 files changed, 0 insertions, 0 deletions