irqchip/armada-370-xp: Report that effective affinity is a single target

The Armada 370 XP driver only targets a single CPU at a time, even if
the notional affinity is wider. Let's inform the core code
about this.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Wei Xu <xuwei5@hisilicon.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Link: http://lkml.kernel.org/r/20170818083925.10108-7-marc.zyngier@arm.com

drivers/irqchip/Kconfig

@@ -66,6 +66,7 @@ config ARMADA_370_XP_IRQ
 	bool
 	select GENERIC_IRQ_CHIP
 	select PCI_MSI if PCI
+	select GENERIC_IRQ_EFFECTIVE_AFF_MASK
 
 config ALPINE_MSI
 	bool

drivers/irqchip/irq-armada-370-xp.c

@@ -330,6 +330,8 @@ static int armada_xp_set_affinity(struct irq_data *d,
 	writel(reg, main_int_base + ARMADA_370_XP_INT_SOURCE_CTL(hwirq));
 	raw_spin_unlock(&irq_controller_lock);
 
+	irq_data_update_effective_affinity(d, cpumask_of(cpu));
+
 	return IRQ_SET_MASK_OK;
 }
 #endif
@@ -363,6 +365,7 @@ static int armada_370_xp_mpic_irq_map(struct irq_domain *h,
 	} else {
 		irq_set_chip_and_handler(virq, &armada_370_xp_irq_chip,
 					handle_level_irq);
+		irqd_set_single_target(irq_desc_get_irq_data(irq_to_desc(virq)));
 	}
 	irq_set_probe(virq);