genirq: Move initial affinity setup to irq_startup()

The startup vs. setaffinity ordering of interrupts depends on the
IRQF_NOAUTOEN flag. Chained interrupts are not getting any affinity
assignment at all.

A regular interrupt is started up and then the affinity is set. A
IRQF_NOAUTOEN marked interrupt is not started up, but the affinity is set
nevertheless.

Move the affinity setup to startup_irq() so the ordering is always the same
and chained interrupts get the proper default affinity assigned as well.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235445.020534783@linutronix.de

kernel/irq/chip.c

@@ -213,6 +213,8 @@ int irq_startup(struct irq_desc *desc, bool resend)
 			irq_enable(desc);
 		}
 		irq_state_set_started(desc);
+		/* Set default affinity mask once everything is setup */
+		irq_setup_affinity(desc);
 	}
 
 	if (resend)

kernel/irq/manage.c

@@ -1327,6 +1327,12 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 		if (new->flags & IRQF_ONESHOT)
 			desc->istate |= IRQS_ONESHOT;
 
+		/* Exclude IRQ from balancing if requested */
+		if (new->flags & IRQF_NOBALANCING) {
+			irq_settings_set_no_balancing(desc);
+			irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
+		}
+
 		if (irq_settings_can_autoenable(desc)) {
 			irq_startup(desc, true);
 		} else {
@@ -1341,15 +1347,6 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 			desc->depth = 1;
 		}
 
-		/* Exclude IRQ from balancing if requested */
-		if (new->flags & IRQF_NOBALANCING) {
-			irq_settings_set_no_balancing(desc);
-			irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
-		}
-
-		/* Set default affinity mask once everything is setup */
-		irq_setup_affinity(desc);
-
 	} else if (new->flags & IRQF_TRIGGER_MASK) {
 		unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
 		unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);