[GIT pull] irq fixes for 4.8

From: Thomas Gleixner
Date: Sun Sep 18 2016 - 04:07:52 EST


Linus,

please pull the latest irq-urgent-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git irq-urgent-for-linus

Two patches from Boris which address a potential deadlock in the atmel irq
chip driver.

Thanks,

tglx

------------------>
Boris Brezillon (2):
genirq: Provide irq_gc_{lock_irqsave,unlock_irqrestore}() helpers
irqchip/atmel-aic: Fix potential deadlock in ->xlate()


drivers/irqchip/irq-atmel-aic.c | 5 +++--
drivers/irqchip/irq-atmel-aic5.c | 5 +++--
include/linux/irq.h | 10 ++++++++++
3 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/drivers/irqchip/irq-atmel-aic.c b/drivers/irqchip/irq-atmel-aic.c
index 112e17c2768b..37f952dd9fc9 100644
--- a/drivers/irqchip/irq-atmel-aic.c
+++ b/drivers/irqchip/irq-atmel-aic.c
@@ -176,6 +176,7 @@ static int aic_irq_domain_xlate(struct irq_domain *d,
{
struct irq_domain_chip_generic *dgc = d->gc;
struct irq_chip_generic *gc;
+ unsigned long flags;
unsigned smr;
int idx;
int ret;
@@ -194,11 +195,11 @@ static int aic_irq_domain_xlate(struct irq_domain *d,

gc = dgc->gc[idx];

- irq_gc_lock(gc);
+ irq_gc_lock_irqsave(gc, flags);
smr = irq_reg_readl(gc, AT91_AIC_SMR(*out_hwirq));
aic_common_set_priority(intspec[2], &smr);
irq_reg_writel(gc, smr, AT91_AIC_SMR(*out_hwirq));
- irq_gc_unlock(gc);
+ irq_gc_unlock_irqrestore(gc, flags);

return ret;
}
diff --git a/drivers/irqchip/irq-atmel-aic5.c b/drivers/irqchip/irq-atmel-aic5.c
index 4f0d068e1abe..2a624d87a035 100644
--- a/drivers/irqchip/irq-atmel-aic5.c
+++ b/drivers/irqchip/irq-atmel-aic5.c
@@ -258,6 +258,7 @@ static int aic5_irq_domain_xlate(struct irq_domain *d,
unsigned int *out_type)
{
struct irq_chip_generic *bgc = irq_get_domain_generic_chip(d, 0);
+ unsigned long flags;
unsigned smr;
int ret;

@@ -269,12 +270,12 @@ static int aic5_irq_domain_xlate(struct irq_domain *d,
if (ret)
return ret;

- irq_gc_lock(bgc);
+ irq_gc_lock_irqsave(bgc, flags);
irq_reg_writel(bgc, *out_hwirq, AT91_AIC5_SSR);
smr = irq_reg_readl(bgc, AT91_AIC5_SMR);
aic_common_set_priority(intspec[2], &smr);
irq_reg_writel(bgc, smr, AT91_AIC5_SMR);
- irq_gc_unlock(bgc);
+ irq_gc_unlock_irqrestore(bgc, flags);

return ret;
}
diff --git a/include/linux/irq.h b/include/linux/irq.h
index b52424eaa0ed..0ac26c892fe2 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -945,6 +945,16 @@ static inline void irq_gc_lock(struct irq_chip_generic *gc) { }
static inline void irq_gc_unlock(struct irq_chip_generic *gc) { }
#endif

+/*
+ * The irqsave variants are for usage in non interrupt code. Do not use
+ * them in irq_chip callbacks. Use irq_gc_lock() instead.
+ */
+#define irq_gc_lock_irqsave(gc, flags) \
+ raw_spin_lock_irqsave(&(gc)->lock, flags)
+
+#define irq_gc_unlock_irqrestore(gc, flags) \
+ raw_spin_unlock_irqrestore(&(gc)->lock, flags)
+
static inline void irq_reg_writel(struct irq_chip_generic *gc,
u32 val, int reg_offset)
{