1 files changed, 66 insertions, 57 deletions

diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 844d3f882a1..f7f376ea7b1 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -118,6 +118,7 @@ notrace void raw_local_irq_restore(unsigned long en)
 	if (!en)
 		return;
 
+#ifdef CONFIG_PPC_STD_MMU_64
 	if (firmware_has_feature(FW_FEATURE_ISERIES)) {
 		/*
 		 * Do we need to disable preemption here?  Not really: in the
@@ -135,6 +136,7 @@ notrace void raw_local_irq_restore(unsigned long en)
 		if (local_paca->lppaca_ptr->int_dword.any_int)
 			iseries_handle_interrupts();
 	}
+#endif /* CONFIG_PPC_STD_MMU_64 */
 
 	if (test_perf_counter_pending()) {
 		clear_perf_counter_pending();
@@ -254,77 +256,84 @@ void fixup_irqs(cpumask_t map)
 }
 #endif
 
-void do_IRQ(struct pt_regs *regs)
-{
-	struct pt_regs *old_regs = set_irq_regs(regs);
-	unsigned int irq;
 #ifdef CONFIG_IRQSTACKS
+static inline void handle_one_irq(unsigned int irq)
+{
 	struct thread_info *curtp, *irqtp;
-#endif
+	unsigned long saved_sp_limit;
+	struct irq_desc *desc;
 
-	irq_enter();
+	/* 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;
+
+	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, desc->handle_irq);
+	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
 
+static inline void check_stack_overflow(void)
+{
 #ifdef CONFIG_DEBUG_STACKOVERFLOW
-	/* Debugging check for stack overflow: is there less than 2KB free? */
-	{
-		long sp;
+	long sp;
 
-		sp = __get_SP() & (THREAD_SIZE-1);
+	sp = __get_SP() & (THREAD_SIZE-1);
 
-		if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
-			printk("do_IRQ: stack overflow: %ld\n",
-				sp - sizeof(struct thread_info));
-			dump_stack();
-		}
+	/* check for stack overflow: is there less than 2KB free? */
+	if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
+		printk("do_IRQ: stack overflow: %ld\n",
+			sp - sizeof(struct thread_info));
+		dump_stack();
 	}
 #endif
+}
 
-	/*
-	 * Every platform is required to implement ppc_md.get_irq.
-	 * This function will either return an irq number or NO_IRQ to
-	 * indicate there are no more pending.
-	 * The value NO_IRQ_IGNORE is for buggy hardware and means that this
-	 * IRQ has already been handled. -- Tom
-	 */
-	irq = ppc_md.get_irq();
+void do_IRQ(struct pt_regs *regs)
+{
+	struct pt_regs *old_regs = set_irq_regs(regs);
+	unsigned int 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);
+	irq_enter();
 
-			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;
+	check_stack_overflow();
 
+	irq = ppc_md.get_irq();
 
-			/* 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++;