irqchip/mips-gic: Cleanup chip and handler setup

gic_shared_irq_domain_map() is called from gic_irq_domain_alloc() where
the wrong chip has been set, and is then overwritten. Tidy this up by
setting the correct chip the first time, and setting the
handle_level_irq handler from gic_irq_domain_alloc() too.

gic_shared_irq_domain_map() is also called from gic_irq_domain_map(),
which now calls irq_set_chip_and_handler() to retain its previous
behaviour.

This patch prepares for a follow-on which will call
gic_shared_irq_domain_map() from a callback where the lock on the struct
irq_desc is held, which without this change would cause the call to
irq_set_chip_and_handler() to lead to a deadlock.

Fixes: c98c1822ee13 ("irqchip/mips-gic: Add device hierarchy domain")
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20160819170715.27820-1-paul.burton@imgtec.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 7 insertions, 4 deletions

diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c
index c5f33c3bd228..2e0f49992a98 100644
--- a/drivers/irqchip/irq-mips-gic.c
+++ b/drivers/irqchip/irq-mips-gic.c
@@ -713,9 +713,6 @@ static int gic_shared_irq_domain_map(struct irq_domain *d, unsigned int virq,
         unsigned long flags;
         int i;
 
-        irq_set_chip_and_handler(virq, &gic_level_irq_controller,
-                                 handle_level_irq);
-
         spin_lock_irqsave(&gic_lock, flags);
         gic_map_to_pin(intr, gic_cpu_pin);
         gic_map_to_vpe(intr, mips_cm_vp_id(vpe));
@@ -732,6 +729,10 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int virq,
 {
         if (GIC_HWIRQ_TO_LOCAL(hw) < GIC_NUM_LOCAL_INTRS)
                 return gic_local_irq_domain_map(d, virq, hw);
+
+        irq_set_chip_and_handler(virq, &gic_level_irq_controller,
+                                 handle_level_irq);
+
         return gic_shared_irq_domain_map(d, virq, hw, 0);
 }
 
@@ -771,11 +772,13 @@ static int gic_irq_domain_alloc(struct irq_domain *d, unsigned int virq,
                         hwirq = GIC_SHARED_TO_HWIRQ(base_hwirq + i);
 
                         ret = irq_domain_set_hwirq_and_chip(d, virq + i, hwirq,
-                                                            &gic_edge_irq_controller,
+                                                            &gic_level_irq_controller,
                                                             NULL);
                         if (ret)
                                 goto error;
 
+                        irq_set_handler(virq + i, handle_level_irq);
+
                         ret = gic_shared_irq_domain_map(d, virq + i, hwirq, cpu);
                         if (ret)
                                 goto error;