[PATCH 1/3] genirq/affinity: Add irq_update_affinity_desc()

[John Garry]

From: Thomas Gleixner <t...@linutronix.de>

Add a function to allow the affinity of an interrupt be switched to
managed, such that interrupts allocated for platform devices may be
managed.

<Insert author sob>
[jpg: Add commit message and add prototypes]
Signed-off-by: John Garry <john.ga...@huawei.com>
---
Thomas, I just made you author since you provided the original code, hope
it's ok.

 include/linux/interrupt.h |  8 ++++++++
 kernel/irq/manage.c       | 19 +++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index ee8299eb1f52..870b3251e174 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -352,6 +352,8 @@ extern int irq_can_set_affinity(unsigned int irq);
 extern int irq_select_affinity(unsigned int irq);
 
 extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m);
+extern int irq_update_affinity_desc(unsigned int irq,
+                                   struct irq_affinity_desc *affinity);
 
 extern int
 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify 
*notify);
@@ -387,6 +389,12 @@ static inline int irq_set_affinity_hint(unsigned int irq,
        return -EINVAL;
 }
 
+static inline int irq_update_affinity_desc(unsigned int irq,
+                                          struct irq_affinity_desc *affinity)
+{
+       return -EINVAL;
+}
+
 static inline int
 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
 {
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index c460e0496006..b96af4cde4bc 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -371,6 +371,25 @@ int irq_set_affinity_locked(struct irq_data *data, const 
struct cpumask *mask,
        return ret;
 }
 
+int irq_update_affinity_desc(unsigned int irq,
+                            struct irq_affinity_desc *affinity)
+{
+       unsigned long flags;
+       struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
+
+       if (!desc)
+               return -EINVAL;
+
+       if (affinity->is_managed) {
+               irqd_set(&desc->irq_data, IRQD_AFFINITY_MANAGED);
+               irqd_set(&desc->irq_data, IRQD_MANAGED_SHUTDOWN);
+       }
+
+       cpumask_copy(desc->irq_common_data.affinity, &affinity->mask);
+       irq_put_desc_unlock(desc, flags);
+       return 0;
+}
+
 int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool 
force)
 {
        struct irq_desc *desc = irq_to_desc(irq);
-- 
2.26.2