powerpc/powernv: process all OPAL event interrupts with kopald

Using irq_work for processing OPAL event interrupts is not necessary.
irq_work is typically used to schedule work from NMI context, a
softirq may be more appropriate. However OPAL events are not
particularly performance or latency critical, so they can all be
invoked by kopald.

This patch removes the irq_work queueing, and instead wakes up
kopald when there is an event to be processed. kopald processes
interrupts individually, enabling irqs and calling cond_resched
between each one to minimise latencies.

Event handlers themselves should still use threaded handlers,
workqueues, etc. as necessary to avoid high interrupts-off latencies
within any single interrupt.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 2 insertions, 1 deletions

diff --git a/arch/powerpc/platforms/powernv/powernv.h b/arch/powerpc/platforms/powernv/powernv.h
index 94f17ab1374b..fd4a1c5a6369 100644
--- a/arch/powerpc/platforms/powernv/powernv.h
+++ b/arch/powerpc/platforms/powernv/powernv.h
@@ -24,7 +24,8 @@ extern u32 pnv_get_supported_cpuidle_states(void);
 
 extern void pnv_lpc_init(void);
 
-extern void opal_handle_events(uint64_t events);
+extern void opal_handle_events(void);
+extern bool opal_have_pending_events(void);
 extern void opal_event_shutdown(void);
 
 bool cpu_core_split_required(void);