1 files changed, 78 insertions, 14 deletions

diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index c687ba4363f2..ba566c261adc 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -166,11 +166,11 @@ int set_irq_data(unsigned int irq, void *data)
 EXPORT_SYMBOL(set_irq_data);
 
 /**
- *      set_irq_data - set irq type data for an irq
+ *      set_irq_msi - set MSI descriptor data for an irq
  *      @irq:   Interrupt number
  *      @entry: Pointer to MSI descriptor data
  *
- *      Set the hardware irq controller data for an irq
+ *      Set the MSI descriptor entry for an irq
  */
 int set_irq_msi(unsigned int irq, struct msi_desc *entry)
 {
@@ -222,6 +222,34 @@ int set_irq_chip_data(unsigned int irq, void *data)
 }
 EXPORT_SYMBOL(set_irq_chip_data);
 
+/**
+ *      set_irq_nested_thread - Set/Reset the IRQ_NESTED_THREAD flag of an irq
+ *
+ *      @irq:   Interrupt number
+ *      @nest:  0 to clear / 1 to set the IRQ_NESTED_THREAD flag
+ *
+ *      The IRQ_NESTED_THREAD flag indicates that on
+ *      request_threaded_irq() no separate interrupt thread should be
+ *      created for the irq as the handler are called nested in the
+ *      context of a demultiplexing interrupt handler thread.
+ */
+void set_irq_nested_thread(unsigned int irq, int nest)
+{
+        struct irq_desc *desc = irq_to_desc(irq);
+        unsigned long flags;
+
+        if (!desc)
+                return;
+
+        spin_lock_irqsave(&desc->lock, flags);
+        if (nest)
+                desc->status |= IRQ_NESTED_THREAD;
+        else
+                desc->status &= ~IRQ_NESTED_THREAD;
+        spin_unlock_irqrestore(&desc->lock, flags);
+}
+EXPORT_SYMBOL_GPL(set_irq_nested_thread);
+
 /*
  * default enable function
  */
@@ -299,6 +327,45 @@ static inline void mask_ack_irq(struct irq_desc *desc, int irq)
         }
 }
 
+/*
+ *      handle_nested_irq - Handle a nested irq from a irq thread
+ *      @irq:   the interrupt number
+ *
+ *      Handle interrupts which are nested into a threaded interrupt
+ *      handler. The handler function is called inside the calling
+ *      threads context.
+ */
+void handle_nested_irq(unsigned int irq)
+{
+        struct irq_desc *desc = irq_to_desc(irq);
+        struct irqaction *action;
+        irqreturn_t action_ret;
+
+        might_sleep();
+
+        spin_lock_irq(&desc->lock);
+
+        kstat_incr_irqs_this_cpu(irq, desc);
+
+        action = desc->action;
+        if (unlikely(!action || (desc->status & IRQ_DISABLED)))
+                goto out_unlock;
+
+        desc->status |= IRQ_INPROGRESS;
+        spin_unlock_irq(&desc->lock);
+
+        action_ret = action->thread_fn(action->irq, action->dev_id);
+        if (!noirqdebug)
+                note_interrupt(irq, desc, action_ret);
+
+        spin_lock_irq(&desc->lock);
+        desc->status &= ~IRQ_INPROGRESS;
+
+out_unlock:
+        spin_unlock_irq(&desc->lock);
+}
+EXPORT_SYMBOL_GPL(handle_nested_irq);
+
 /**
  *      handle_simple_irq - Simple and software-decoded IRQs.
  *      @irq:   the interrupt number
@@ -359,7 +426,6 @@ handle_level_irq(unsigned int irq, struct irq_desc *desc)
 
         spin_lock(&desc->lock);
         mask_ack_irq(desc, irq);
-        desc = irq_remap_to_desc(irq, desc);
 
         if (unlikely(desc->status & IRQ_INPROGRESS))
                 goto out_unlock;
@@ -383,7 +449,10 @@ handle_level_irq(unsigned int irq, struct irq_desc *desc)
 
         spin_lock(&desc->lock);
         desc->status &= ~IRQ_INPROGRESS;
-        if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
+
+        if (unlikely(desc->status & IRQ_ONESHOT))
+                desc->status |= IRQ_MASKED;
+        else if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
                 desc->chip->unmask(irq);
 out_unlock:
         spin_unlock(&desc->lock);
@@ -438,7 +507,6 @@ handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
         desc->status &= ~IRQ_INPROGRESS;
 out:
         desc->chip->eoi(irq);
-        desc = irq_remap_to_desc(irq, desc);
 
         spin_unlock(&desc->lock);
 }
@@ -475,7 +543,6 @@ handle_edge_irq(unsigned int irq, struct irq_desc *desc)
                     !desc->action)) {
                 desc->status |= (IRQ_PENDING | IRQ_MASKED);
                 mask_ack_irq(desc, irq);
-                desc = irq_remap_to_desc(irq, desc);
                 goto out_unlock;
         }
         kstat_incr_irqs_this_cpu(irq, desc);
@@ -483,7 +550,6 @@ handle_edge_irq(unsigned int irq, struct irq_desc *desc)
         /* Start handling the irq */
         if (desc->chip->ack)
                 desc->chip->ack(irq);
-        desc = irq_remap_to_desc(irq, desc);
 
         /* Mark the IRQ currently in progress.*/
         desc->status |= IRQ_INPROGRESS;
@@ -524,7 +590,7 @@ out_unlock:
 }
 
 /**
- *      handle_percpu_IRQ - Per CPU local irq handler
+ *      handle_percpu_irq - Per CPU local irq handler
  *      @irq:   the interrupt number
  *      @desc:  the interrupt description structure for this irq
  *
@@ -544,10 +610,8 @@ handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
         if (!noirqdebug)
                 note_interrupt(irq, desc, action_ret);
 
-        if (desc->chip->eoi) {
+        if (desc->chip->eoi)
                 desc->chip->eoi(irq);
-                desc = irq_remap_to_desc(irq, desc);
-        }
 }
 
 void
@@ -578,14 +642,13 @@ __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
                 desc->chip = &dummy_irq_chip;
         }
 
+        chip_bus_lock(irq, desc);
         spin_lock_irqsave(&desc->lock, flags);
 
         /* Uninstall? */
         if (handle == handle_bad_irq) {
-                if (desc->chip != &no_irq_chip) {
+                if (desc->chip != &no_irq_chip)
                         mask_ack_irq(desc, irq);
-                        desc = irq_remap_to_desc(irq, desc);
-                }
                 desc->status |= IRQ_DISABLED;
                 desc->depth = 1;
         }
@@ -599,6 +662,7 @@ __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
                 desc->chip->startup(irq);
         }
         spin_unlock_irqrestore(&desc->lock, flags);
+        chip_bus_sync_unlock(irq, desc);
 }
 EXPORT_SYMBOL_GPL(__set_irq_handler);