1 files changed, 28 insertions, 0 deletions

diff --git a/arch/parisc/kernel/irq.c b/arch/parisc/kernel/irq.c
index 61e51ac85659..810f9cf89e48 100644
--- a/arch/parisc/kernel/irq.c
+++ b/arch/parisc/kernel/irq.c
@@ -358,6 +358,29 @@ static inline void stack_overflow_check(struct pt_regs *regs)
 #endif
 }
 
+#ifdef CONFIG_IRQSTACKS
+DEFINE_PER_CPU(union irq_stack_union, irq_stack_union);
+
+static void execute_on_irq_stack(void *func, unsigned long param1)
+{
+        unsigned long *irq_stack_start;
+        unsigned long irq_stack;
+        int cpu = smp_processor_id();
+
+        irq_stack_start = &per_cpu(irq_stack_union, cpu).stack[0];
+        irq_stack = (unsigned long) irq_stack_start;
+        irq_stack = ALIGN(irq_stack, 16); /* align for stack frame usage */
+
+        BUG_ON(*irq_stack_start); /* report bug if we were called recursive. */
+        *irq_stack_start = 1;
+
+        /* This is where we switch to the IRQ stack. */
+        call_on_stack(param1, func, irq_stack);
+
+        *irq_stack_start = 0;
+}
+#endif /* CONFIG_IRQSTACKS */
+
 /* ONLY called from entry.S:intr_extint() */
 void do_cpu_irq_mask(struct pt_regs *regs)
 {
@@ -393,7 +416,12 @@ void do_cpu_irq_mask(struct pt_regs *regs)
         }
 #endif
         stack_overflow_check(regs);
+
+#ifdef CONFIG_IRQSTACKS
+        execute_on_irq_stack(&generic_handle_irq, irq);
+#else
         generic_handle_irq(irq);
+#endif /* CONFIG_IRQSTACKS */
 
  out:
         irq_exit();