[PATCH v3 3/4] genirq: Split irq_set_affinity() so it can be called with lock held.

From: David Daney
Date: Fri Mar 25 2011 - 15:39:18 EST


The .irq_cpu_online() and .irq_cpu_offline() functions may need to
adjust affinity, but they are called with the descriptor lock held.
Create __irq_set_affinity_locked() which is called with the lock held.
Make irq_set_affinity() just a wrapper that acquires the lock.

Signed-off-by: David Daney <ddaney@xxxxxxxxxxxxxxxxxx>
---
include/linux/interrupt.h | 2 ++
kernel/irq/manage.c | 40 ++++++++++++++++++++++++++--------------
2 files changed, 28 insertions(+), 14 deletions(-)

diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 59b72ca..815f9fb 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -229,6 +229,8 @@ static inline int check_wakeup_irqs(void) { return 0; }
extern cpumask_var_t irq_default_affinity;

extern int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask);
+extern int __irq_set_affinity_locked(struct irq_desc *desc,
+ const struct cpumask *cpumask);
extern int irq_can_set_affinity(unsigned int irq);
extern int irq_select_affinity(unsigned int irq);

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 0a2aa73..3d3bed1 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -139,24 +139,12 @@ static inline void
irq_get_pending(struct cpumask *mask, struct irq_desc *desc) { }
#endif

-/**
- * irq_set_affinity - Set the irq affinity of a given irq
- * @irq: Interrupt to set affinity
- * @cpumask: cpumask
- *
- */
-int irq_set_affinity(unsigned int irq, const struct cpumask *mask)
+
+int __irq_set_affinity_locked(struct irq_desc *desc, const struct cpumask *mask)
{
- struct irq_desc *desc = irq_to_desc(irq);
struct irq_chip *chip = desc->irq_data.chip;
- unsigned long flags;
int ret = 0;

- if (!chip->irq_set_affinity)
- return -EINVAL;
-
- raw_spin_lock_irqsave(&desc->lock, flags);
-
if (irq_can_move_pcntxt(desc)) {
ret = chip->irq_set_affinity(&desc->irq_data, mask, false);
switch (ret) {
@@ -177,6 +165,30 @@ int irq_set_affinity(unsigned int irq, const struct cpumask *mask)
}
irq_compat_set_affinity(desc);
irqd_set(&desc->irq_data, IRQD_AFFINITY_SET);
+
+ return ret;
+}
+
+/**
+ * irq_set_affinity - Set the irq affinity of a given irq
+ * @irq: Interrupt to set affinity
+ * @cpumask: cpumask
+ *
+ */
+int irq_set_affinity(unsigned int irq, const struct cpumask *mask)
+{
+ struct irq_desc *desc = irq_to_desc(irq);
+ struct irq_chip *chip = desc->irq_data.chip;
+ unsigned long flags;
+ int ret;
+
+ if (!chip->irq_set_affinity)
+ return -EINVAL;
+
+ raw_spin_lock_irqsave(&desc->lock, flags);
+
+ ret = __irq_set_affinity_locked(desc, mask);
+
raw_spin_unlock_irqrestore(&desc->lock, flags);
return ret;
}
--
1.7.2.3

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