1 files changed, 125 insertions, 2 deletions

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 886d09e691d5..e68932bb308e 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -68,14 +68,20 @@ static void __synchronize_hardirq(struct irq_desc *desc)
  *      Do not use this for shutdown scenarios where you must be sure
  *      that all parts (hardirq and threaded handler) have completed.
  *
+ *      Returns: false if a threaded handler is active.
+ *
  *      This function may be called - with care - from IRQ context.
  */
-void synchronize_hardirq(unsigned int irq)
+bool synchronize_hardirq(unsigned int irq)
 {
         struct irq_desc *desc = irq_to_desc(irq);
 
-        if (desc)
+        if (desc) {
                 __synchronize_hardirq(desc);
+                return !atomic_read(&desc->threads_active);
+        }
+
+        return true;
 }
 EXPORT_SYMBOL(synchronize_hardirq);
 
@@ -440,6 +446,32 @@ void disable_irq(unsigned int irq)
 }
 EXPORT_SYMBOL(disable_irq);
 
+/**
+ *      disable_hardirq - disables an irq and waits for hardirq completion
+ *      @irq: Interrupt to disable
+ *
+ *      Disable the selected interrupt line.  Enables and Disables are
+ *      nested.
+ *      This function waits for any pending hard IRQ handlers for this
+ *      interrupt to complete before returning. If you use this function while
+ *      holding a resource the hard IRQ handler may need you will deadlock.
+ *
+ *      When used to optimistically disable an interrupt from atomic context
+ *      the return value must be checked.
+ *
+ *      Returns: false if a threaded handler is active.
+ *
+ *      This function may be called - with care - from IRQ context.
+ */
+bool disable_hardirq(unsigned int irq)
+{
+        if (!__disable_irq_nosync(irq))
+                return synchronize_hardirq(irq);
+
+        return false;
+}
+EXPORT_SYMBOL_GPL(disable_hardirq);
+
 void __enable_irq(struct irq_desc *desc, unsigned int irq)
 {
         switch (desc->depth) {
@@ -1766,3 +1798,94 @@ int request_percpu_irq(unsigned int irq, irq_handler_t handler,
 
         return retval;
 }
+
+/**
+ *      irq_get_irqchip_state - returns the irqchip state of a interrupt.
+ *      @irq: Interrupt line that is forwarded to a VM
+ *      @which: One of IRQCHIP_STATE_* the caller wants to know about
+ *      @state: a pointer to a boolean where the state is to be storeed
+ *
+ *      This call snapshots the internal irqchip state of an
+ *      interrupt, returning into @state the bit corresponding to
+ *      stage @which
+ *
+ *      This function should be called with preemption disabled if the
+ *      interrupt controller has per-cpu registers.
+ */
+int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
+                          bool *state)
+{
+        struct irq_desc *desc;
+        struct irq_data *data;
+        struct irq_chip *chip;
+        unsigned long flags;
+        int err = -EINVAL;
+
+        desc = irq_get_desc_buslock(irq, &flags, 0);
+        if (!desc)
+                return err;
+
+        data = irq_desc_get_irq_data(desc);
+
+        do {
+                chip = irq_data_get_irq_chip(data);
+                if (chip->irq_get_irqchip_state)
+                        break;
+#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
+                data = data->parent_data;
+#else
+                data = NULL;
+#endif
+        } while (data);
+
+        if (data)
+                err = chip->irq_get_irqchip_state(data, which, state);
+
+        irq_put_desc_busunlock(desc, flags);
+        return err;
+}
+
+/**
+ *      irq_set_irqchip_state - set the state of a forwarded interrupt.
+ *      @irq: Interrupt line that is forwarded to a VM
+ *      @which: State to be restored (one of IRQCHIP_STATE_*)
+ *      @val: Value corresponding to @which
+ *
+ *      This call sets the internal irqchip state of an interrupt,
+ *      depending on the value of @which.
+ *
+ *      This function should be called with preemption disabled if the
+ *      interrupt controller has per-cpu registers.
+ */
+int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
+                          bool val)
+{
+        struct irq_desc *desc;
+        struct irq_data *data;
+        struct irq_chip *chip;
+        unsigned long flags;
+        int err = -EINVAL;
+
+        desc = irq_get_desc_buslock(irq, &flags, 0);
+        if (!desc)
+                return err;
+
+        data = irq_desc_get_irq_data(desc);
+
+        do {
+                chip = irq_data_get_irq_chip(data);
+                if (chip->irq_set_irqchip_state)
+                        break;
+#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
+                data = data->parent_data;
+#else
+                data = NULL;
+#endif
+        } while (data);
+
+        if (data)
+                err = chip->irq_set_irqchip_state(data, which, val);
+
+        irq_put_desc_busunlock(desc, flags);
+        return err;
+}