[PATCH v3 1/7] genirq: Provide generic_handle_irq_safe().

[Sebastian Andrzej Siewior]

Provide generic_handle_irq_safe() which can used from any context.

Suggested-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Reviewed-by: Oleksandr Natalenko <oleksandr@xxxxxxxxxxxxxx>
Reviewed-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
---

v2…v3: Correct kernel doc for generic_handle_irq_safe() as per Wolfram
       Sang.

 include/linux/irqdesc.h |  1 +
 kernel/irq/irqdesc.c    | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h
index 93d270ca0c567..a77584593f7d1 100644
--- a/include/linux/irqdesc.h
+++ b/include/linux/irqdesc.h
@@ -160,6 +160,7 @@ static inline void generic_handle_irq_desc(struct irq_desc *desc)
 
 int handle_irq_desc(struct irq_desc *desc);
 int generic_handle_irq(unsigned int irq);
+int generic_handle_irq_safe(unsigned int irq);
 
 #ifdef CONFIG_IRQ_DOMAIN
 /*
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index 2267e6527db3c..346d283d2da14 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -662,6 +662,29 @@ int generic_handle_irq(unsigned int irq)
 }
 EXPORT_SYMBOL_GPL(generic_handle_irq);
 
+/**
+ * generic_handle_irq_safe - Invoke the handler for a particular irq from any
+ *			     context.
+ * @irq:	The irq number to handle
+ *
+ * Returns:	0 on success, a negative value on error.
+ *
+ * This function can be called from any context (IRQ or process context). It
+ * will report an error if not invoked from IRQ context and the irq has been
+ * marked to enforce IRQ-context only.
+ */
+int generic_handle_irq_safe(unsigned int irq)
+{
+	unsigned long flags;
+	int ret;
+
+	local_irq_save(flags);
+	ret = handle_irq_desc(irq_to_desc(irq));
+	local_irq_restore(flags);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(generic_handle_irq_safe);
+
 #ifdef CONFIG_IRQ_DOMAIN
 /**
  * generic_handle_domain_irq - Invoke the handler for a HW irq belonging
-- 
2.34.1