powerpc/xics: Properly set Edge/Level type and enable resend

This sets the type of the interrupt appropriately. We set it as follow:

 - If not mapped from the device-tree, we use edge. This is the case
of the virtual interrupts and PCI MSIs for example.

 - If mapped from the device-tree and #interrupt-cells is 2 (PAPR
compliant), we use the second cell to set the appropriate type

 - If mapped from the device-tree and #interrupt-cells is 1 (current
OPAL on P8 does that), we assume level sensitive since those are
typically going to be the PSI LSIs which are level sensitive.

Additionally, we mark the interrupts requested via the opal_interrupts
property all level. This is a bit fishy but the best we can do until we
fix OPAL to properly expose them with a complete descriptor. It is also
correct for the current HW anyway as OPAL interrupts are currently PCI
error and PSI interrupts which are level.

Finally now that edge interrupts are properly identified, we can enable
CONFIG_HARDIRQS_SW_RESEND which will make the core re-send them if
they occur while masked, which some drivers rely upon.

This fixes issues with lost interrupts on some Mellanox adapters.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 2 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/xics.h b/arch/powerpc/include/asm/xics.h
index f5f729c11578..f0b238516e9b 100644
--- a/arch/powerpc/include/asm/xics.h
+++ b/arch/powerpc/include/asm/xics.h
@@ -159,6 +159,8 @@ extern void xics_teardown_cpu(void);
 extern void xics_kexec_teardown_cpu(int secondary);
 extern void xics_migrate_irqs_away(void);
 extern void icp_native_eoi(struct irq_data *d);
+extern int xics_set_irq_type(struct irq_data *d, unsigned int flow_type);
+extern int xics_retrigger(struct irq_data *data);
 #ifdef CONFIG_SMP
 extern int xics_get_irq_server(unsigned int virq, const struct cpumask *cpumask,
 			       unsigned int strict_check);