[PATCH] FRV: permit __do_IRQ() to be dispensed with

Permit __do_IRQ() to be dispensed with based on a configuration option.

Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/frv/Kconfig

@@ -29,6 +29,10 @@ config GENERIC_HARDIRQS
 	bool
 	default y
 
+config GENERIC_HARDIRQS_NO__DO_IRQ
+	bool
+	default y
+
 config GENERIC_TIME
 	bool
 	default y

include/linux/irq.h

@@ -320,7 +320,9 @@ handle_irq_name(void fastcall (*handle)(unsigned int, struct irq_desc *,
  * Monolithic do_IRQ implementation.
  * (is an explicit fastcall, because i386 4KSTACKS calls it from assembly)
  */
+#ifndef CONFIG_GENERIC_HARDIRQS_NO__DO_IRQ
 extern fastcall unsigned int __do_IRQ(unsigned int irq, struct pt_regs *regs);
+#endif
 
 /*
  * Architectures call this to let the generic IRQ layer
@@ -332,10 +334,14 @@ static inline void generic_handle_irq(unsigned int irq, struct pt_regs *regs)
 {
 	struct irq_desc *desc = irq_desc + irq;
 
+#ifdef CONFIG_GENERIC_HARDIRQS_NO__DO_IRQ
+	desc->handle_irq(irq, desc, regs);
+#else
 	if (likely(desc->handle_irq))
 		desc->handle_irq(irq, desc, regs);
 	else
 		__do_IRQ(irq, regs);
+#endif
 }
 
 /* Handling of unhandled and spurious interrupts: */

kernel/irq/handle.c

@@ -154,6 +154,7 @@ irqreturn_t handle_IRQ_event(unsigned int irq, struct pt_regs *regs,
 	return retval;
 }
 
+#ifndef CONFIG_GENERIC_HARDIRQS_NO__DO_IRQ
 /**
  * __do_IRQ - original all in one highlevel IRQ handler
  * @irq:	the interrupt number
@@ -253,6 +254,7 @@ fastcall unsigned int __do_IRQ(unsigned int irq, struct pt_regs *regs)
 
 	return 1;
 }
+#endif
 
 #ifdef CONFIG_TRACE_IRQFLAGS