Provide flow handlers that are NMI safe for interrupts and percpu_devid
interrupts.

Signed-off-by: Julien Thierry <julien.thie...@arm.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Marc Zyngier <marc.zyng...@arm.com>
Cc: Peter Zijlstra <pet...@infradead.org>
---
 include/linux/irq.h |  3 +++
 kernel/irq/chip.c   | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+)

diff --git a/include/linux/irq.h b/include/linux/irq.h
index 0d71f63..88cbad3 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -600,6 +600,9 @@ static inline int irq_set_parent(int irq, int parent_irq)
 extern void handle_bad_irq(struct irq_desc *desc);
 extern void handle_nested_irq(unsigned int irq);
 
+extern void handle_fasteoi_nmi(struct irq_desc *desc);
+extern void handle_percpu_devid_fasteoi_nmi(struct irq_desc *desc);
+
 extern int irq_chip_compose_msi_msg(struct irq_data *data, struct msi_msg 
*msg);
 extern int irq_chip_pm_get(struct irq_data *data);
 extern int irq_chip_pm_put(struct irq_data *data);
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index a2b3d9d..c332c17 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -730,6 +730,37 @@ void handle_fasteoi_irq(struct irq_desc *desc)
 EXPORT_SYMBOL_GPL(handle_fasteoi_irq);
 
 /**
+ *     handle_fasteoi_nmi - irq handler for NMI interrupt lines
+ *     @desc:  the interrupt description structure for this irq
+ *
+ *     A simple NMI-safe handler, considering the restrictions
+ *     from request_nmi.
+ *
+ *     Only a single callback will be issued to the chip: an ->eoi()
+ *     call when the interrupt has been serviced. This enables support
+ *     for modern forms of interrupt handlers, which handle the flow
+ *     details in hardware, transparently.
+ */
+void handle_fasteoi_nmi(struct irq_desc *desc)
+{
+       struct irq_chip *chip = irq_desc_get_chip(desc);
+       struct irqaction *action = desc->action;
+       unsigned int irq = irq_desc_get_irq(desc);
+       irqreturn_t res;
+
+       trace_irq_handler_entry(irq, action);
+       /*
+        * NMIs cannot be shared, there is only one action.
+        */
+       res = action->handler(irq, action->dev_id);
+       trace_irq_handler_exit(irq, action, res);
+
+       if (chip->irq_eoi)
+               chip->irq_eoi(&desc->irq_data);
+}
+EXPORT_SYMBOL_GPL(handle_fasteoi_nmi);
+
+/**
  *     handle_edge_irq - edge type IRQ handler
  *     @desc:  the interrupt description structure for this irq
  *
@@ -908,6 +939,29 @@ void handle_percpu_devid_irq(struct irq_desc *desc)
                chip->irq_eoi(&desc->irq_data);
 }
 
+/**
+ * handle_percpu_devid_fasteoi_nmi - Per CPU local NMI handler with per cpu
+ *                                  dev ids
+ * @desc:      the interrupt description structure for this irq
+ *
+ * Similar to handle_fasteoi_nmi, but handling the dev_id cookie
+ * as a percpu pointer.
+ */
+void handle_percpu_devid_fasteoi_nmi(struct irq_desc *desc)
+{
+       struct irq_chip *chip = irq_desc_get_chip(desc);
+       struct irqaction *action = desc->action;
+       unsigned int irq = irq_desc_get_irq(desc);
+       irqreturn_t res;
+
+       trace_irq_handler_entry(irq, action);
+       res = action->handler(irq, raw_cpu_ptr(action->percpu_dev_id));
+       trace_irq_handler_exit(irq, action, res);
+
+       if (chip->irq_eoi)
+               chip->irq_eoi(&desc->irq_data);
+}
+
 static void
 __irq_do_set_handler(struct irq_desc *desc, irq_flow_handler_t handle,
                     int is_chained, const char *name)
-- 
1.9.1

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