Some IRQ chips may be located in a power domain outside of the CPU
subsystem and hence will require device specific runtime power management.
In order to support such IRQ chips, add a pointer for a device structure
to the irq_chip structure, and if this pointer is populated by the IRQ
chip driver and the flag CHIP_HAS_RPM is set, then the pm_runtime_get/put
APIs for this chip will be called when an IRQ is requested/freed,
respectively.

Signed-off-by: Jon Hunter <jonath...@nvidia.com>
---
 include/linux/irq.h    |  4 ++++
 kernel/irq/internals.h | 24 ++++++++++++++++++++++++
 kernel/irq/manage.c    |  7 +++++++
 3 files changed, 35 insertions(+)

diff --git a/include/linux/irq.h b/include/linux/irq.h
index 3c1c96786248..7a61a7f76177 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -307,6 +307,7 @@ static inline irq_hw_number_t irqd_to_hwirq(struct irq_data 
*d)
 /**
  * struct irq_chip - hardware interrupt chip descriptor
  *
+ * @dev:               pointer to associated device
  * @name:              name for /proc/interrupts
  * @irq_startup:       start up the interrupt (defaults to ->enable if NULL)
  * @irq_shutdown:      shut down the interrupt (defaults to ->disable if NULL)
@@ -344,6 +345,7 @@ static inline irq_hw_number_t irqd_to_hwirq(struct irq_data 
*d)
  * @flags:             chip specific flags
  */
 struct irq_chip {
+       struct device   *dev;
        const char      *name;
        unsigned int    (*irq_startup)(struct irq_data *data);
        void            (*irq_shutdown)(struct irq_data *data);
@@ -399,6 +401,7 @@ struct irq_chip {
  * IRQCHIP_SKIP_SET_WAKE:      Skip chip.irq_set_wake(), for this irq chip
  * IRQCHIP_ONESHOT_SAFE:       One shot does not require mask/unmask
  * IRQCHIP_EOI_THREADED:       Chip requires eoi() on unmask in threaded mode
+ * IRQCHIP_HAS_PM:             Chip requires runtime power management
  */
 enum {
        IRQCHIP_SET_TYPE_MASKED         = (1 <<  0),
@@ -408,6 +411,7 @@ enum {
        IRQCHIP_SKIP_SET_WAKE           = (1 <<  4),
        IRQCHIP_ONESHOT_SAFE            = (1 <<  5),
        IRQCHIP_EOI_THREADED            = (1 <<  6),
+       IRQCHIP_HAS_RPM                 = (1 <<  7),
 };
 
 #include <linux/irqdesc.h>
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index fcab63c66905..30a2add7cae6 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -7,6 +7,7 @@
  */
 #include <linux/irqdesc.h>
 #include <linux/kernel_stat.h>
+#include <linux/pm_runtime.h>
 
 #ifdef CONFIG_SPARSE_IRQ
 # define IRQ_BITMAP_BITS       (NR_IRQS + 8196)
@@ -125,6 +126,29 @@ static inline void chip_bus_sync_unlock(struct irq_desc 
*desc)
                desc->irq_data.chip->irq_bus_sync_unlock(&desc->irq_data);
 }
 
+/* Inline functions for support of irq chips that require runtime pm */
+static inline int chip_pm_get(struct irq_desc *desc)
+{
+       int retval = 0;
+
+       if (desc->irq_data.chip->dev &&
+           desc->irq_data.chip->flags & IRQCHIP_HAS_RPM)
+               retval = pm_runtime_get_sync(desc->irq_data.chip->dev);
+
+       return (retval < 0) ? retval : 0;
+}
+
+static inline int chip_pm_put(struct irq_desc *desc)
+{
+       int retval = 0;
+
+       if (desc->irq_data.chip->dev &&
+           desc->irq_data.chip->flags & IRQCHIP_HAS_RPM)
+               retval = pm_runtime_put(desc->irq_data.chip->dev);
+
+       return (retval < 0) ? retval : 0;
+}
+
 #define _IRQ_DESC_CHECK                (1 << 0)
 #define _IRQ_DESC_PERCPU       (1 << 1)
 
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 2a429b061171..8a96e4f1e985 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1116,6 +1116,10 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, 
struct irqaction *new)
        if (!try_module_get(desc->owner))
                return -ENODEV;
 
+       ret = chip_pm_get(desc);
+       if (ret < 0)
+               return ret;
+
        new->irq = irq;
 
        /*
@@ -1400,6 +1404,7 @@ out_thread:
                put_task_struct(t);
        }
 out_mput:
+       chip_pm_put(desc);
        module_put(desc->owner);
        return ret;
 }
@@ -1513,6 +1518,7 @@ static struct irqaction *__free_irq(unsigned int irq, 
void *dev_id)
                }
        }
 
+       chip_pm_put(desc);
        module_put(desc->owner);
        kfree(action->secondary);
        return action;
@@ -1799,6 +1805,7 @@ static struct irqaction *__free_percpu_irq(unsigned int 
irq, void __percpu *dev_
 
        unregister_handler_proc(irq, action);
 
+       chip_pm_put(desc);
        module_put(desc->owner);
        return action;
 
-- 
2.1.4

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