m68k: Use generic idle loop

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Link: http://lkml.kernel.org/r/20130321215234.535485189@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/m68k/Kconfig

@@ -6,6 +6,7 @@ config M68K
 	select HAVE_DEBUG_BUGVERBOSE
 	select HAVE_GENERIC_HARDIRQS
 	select GENERIC_IRQ_SHOW
+	select GENERIC_IDLE_LOOP
 	select GENERIC_ATOMIC64
 	select HAVE_UID16
 	select VIRT_TO_BUS

arch/m68k/kernel/process.c

@@ -51,40 +51,16 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
 		return sw->retpc;
 }
 
-/*
- * The idle loop on an m68k..
- */
-static void default_idle(void)
+void arch_cpu_idle(void)
 {
-	if (!need_resched())
 #if defined(MACH_ATARI_ONLY)
-		/* block out HSYNC on the atari (falcon) */
-		__asm__("stop #0x2200" : : : "cc");
+	/* block out HSYNC on the atari (falcon) */
+	__asm__("stop #0x2200" : : : "cc");
 #else
-		__asm__("stop #0x2000" : : : "cc");
+	__asm__("stop #0x2000" : : : "cc");
 #endif
 }
 
-void (*idle)(void) = default_idle;
-
-/*
- * The idle thread. There's no useful work to be
- * done, so just try to conserve power and have a
- * low exit latency (ie sit in a loop waiting for
- * somebody to say that they'd like to reschedule)
- */
-void cpu_idle(void)
-{
-	/* endless idle loop with no priority at all */
-	while (1) {
-		rcu_idle_enter();
-		while (!need_resched())
-			idle();
-		rcu_idle_exit();
-		schedule_preempt_disabled();
-	}
-}
-
 void machine_restart(char * __unused)
 {
 	if (mach_reset)