blackfin: Use generic idle thread allocation

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Link: http://lkml.kernel.org/r/20120420124557.717064871@linutronix.de

arch/blackfin/Kconfig

@@ -37,6 +37,7 @@ config BLACKFIN
 	select GENERIC_IRQ_PROBE
 	select IRQ_PER_CPU if SMP
 	select HAVE_NMI_WATCHDOG if NMI_WATCHDOG
+	select GENERIC_SMP_IDLE_THREAD
 
 config GENERIC_CSUM
 	def_bool y

arch/blackfin/mach-common/smp.c

@@ -340,27 +340,10 @@ void smp_send_stop(void)
 	return;
 }
 
-int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *tidle)
+int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *idle)
 {
 	int ret;
-	struct blackfin_cpudata *ci = &per_cpu(cpu_data, cpu);
-	struct task_struct *idle = ci->idle;
 
-	if (idle) {
-		free_task(idle);
-		idle = NULL;
-	}
-
-	if (!idle) {
-		idle = fork_idle(cpu);
-		if (IS_ERR(idle)) {
-			printk(KERN_ERR "CPU%u: fork() failed\n", cpu);
-			return PTR_ERR(idle);
-		}
-		ci->idle = idle;
-	} else {
-		init_idle(idle, cpu);
-	}
 	secondary_stack = task_stack_page(idle) + THREAD_SIZE;
 
 	ret = platform_boot_secondary(cpu, idle);