[tip:x86/urgent] irqchip/mips-gic: Cleanup chip and handler setup

From: tip-bot for Paul Burton
Date: Mon Aug 22 2016 - 11:15:52 EST


Commit-ID: 437844c1f96ceeb7153c09cc92d29b48b9beb337
Gitweb: http://git.kernel.org/tip/437844c1f96ceeb7153c09cc92d29b48b9beb337
Author: Paul Burton <paul.burton@xxxxxxxxxx>
AuthorDate: Fri, 19 Aug 2016 18:07:14 +0100
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Mon, 22 Aug 2016 17:07:34 +0200

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@xxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: Jason Cooper <jason@xxxxxxxxxxxxxx>
Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20160819170715.27820-1-paul.burton@xxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

---
drivers/irqchip/irq-mips-gic.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c
index c5f33c3..2e0f499 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;