powerpc/irq: Move #ifdef'ed body of do_IRQ() into a separate function

Rather than a giant ifdef in the body of do_IRQ(), including a
dangling else, move the irq stack logic into a separate routine and
do the ifdef there.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 56 insertions, 40 deletions

diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 8c1a4966867e..3d3658d0b7b9 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -248,13 +248,63 @@ void fixup_irqs(cpumask_t map)
 }
 #endif
 
+#ifdef CONFIG_IRQSTACKS
+static inline void handle_one_irq(unsigned int irq)
+{
+        struct thread_info *curtp, *irqtp;
+        unsigned long saved_sp_limit;
+        struct irq_desc *desc;
+        void *handler;
+
+        /* Switch to the irq stack to handle this */
+        curtp = current_thread_info();
+        irqtp = hardirq_ctx[smp_processor_id()];
+
+        if (curtp == irqtp) {
+                /* We're already on the irq stack, just handle it */
+                generic_handle_irq(irq);
+                return;
+        }
+
+        desc = irq_desc + irq;
+        saved_sp_limit = current->thread.ksp_limit;
+
+        handler = desc->handle_irq;
+        if (handler == NULL)
+                handler = &__do_IRQ;
+
+        irqtp->task = curtp->task;
+        irqtp->flags = 0;
+
+        /* Copy the softirq bits in preempt_count so that the
+         * softirq checks work in the hardirq context. */
+        irqtp->preempt_count = (irqtp->preempt_count & ~SOFTIRQ_MASK) |
+                               (curtp->preempt_count & SOFTIRQ_MASK);
+
+        current->thread.ksp_limit = (unsigned long)irqtp +
+                _ALIGN_UP(sizeof(struct thread_info), 16);
+
+        call_handle_irq(irq, desc, irqtp, handler);
+        current->thread.ksp_limit = saved_sp_limit;
+        irqtp->task = NULL;
+
+        /* Set any flag that may have been set on the
+         * alternate stack
+         */
+        if (irqtp->flags)
+                set_bits(irqtp->flags, &curtp->flags);
+}
+#else
+static inline void handle_one_irq(unsigned int irq)
+{
+        generic_handle_irq(irq);
+}
+#endif
+
 void do_IRQ(struct pt_regs *regs)
 {
         struct pt_regs *old_regs = set_irq_regs(regs);
         unsigned int irq;
-#ifdef CONFIG_IRQSTACKS
-        struct thread_info *curtp, *irqtp;
-#endif
 
         irq_enter();
 
@@ -282,43 +332,9 @@ void do_IRQ(struct pt_regs *regs)
          */
         irq = ppc_md.get_irq();
 
-        if (irq != NO_IRQ && irq != NO_IRQ_IGNORE) {
-#ifdef CONFIG_IRQSTACKS
-                /* Switch to the irq stack to handle this */
-                curtp = current_thread_info();
-                irqtp = hardirq_ctx[smp_processor_id()];
-                if (curtp != irqtp) {
-                        struct irq_desc *desc = irq_desc + irq;
-                        void *handler = desc->handle_irq;
-                        unsigned long saved_sp_limit = current->thread.ksp_limit;
-                        if (handler == NULL)
-                                handler = &__do_IRQ;
-                        irqtp->task = curtp->task;
-                        irqtp->flags = 0;
-
-                        /* Copy the softirq bits in preempt_count so that the
-                         * softirq checks work in the hardirq context.
-                         */
-                        irqtp->preempt_count =
-                                (irqtp->preempt_count & ~SOFTIRQ_MASK) |
-                                (curtp->preempt_count & SOFTIRQ_MASK);
-
-                        current->thread.ksp_limit = (unsigned long)irqtp +
-                                _ALIGN_UP(sizeof(struct thread_info), 16);
-                        call_handle_irq(irq, desc, irqtp, handler);
-                        current->thread.ksp_limit = saved_sp_limit;
-                        irqtp->task = NULL;
-
-
-                        /* Set any flag that may have been set on the
-                         * alternate stack
-                         */
-                        if (irqtp->flags)
-                                set_bits(irqtp->flags, &curtp->flags);
-                } else
-#endif
-                        generic_handle_irq(irq);
-        } else if (irq != NO_IRQ_IGNORE)
+        if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
+                handle_one_irq(irq);
+        else if (irq != NO_IRQ_IGNORE)
                 /* That's not SMP safe ... but who cares ? */
                 ppc_spurious_interrupts++;