parisc: 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: James E.J. Bottomley <jejb@parisc-linux.org>
Link: http://lkml.kernel.org/r/20120420124557.988947805@linutronix.de

arch/parisc/Kconfig

@@ -17,6 +17,7 @@ config PARISC
 	select GENERIC_PCI_IOMAP
 	select IRQ_PER_CPU
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
+	select GENERIC_SMP_IDLE_THREAD
 
 	help
 	  The PA-RISC microprocessor is designed by Hewlett-Packard and used

arch/parisc/kernel/smp.c

@@ -334,26 +334,11 @@ void __init smp_callin(void)
 /*
  * Bring one cpu online.
  */
-int __cpuinit smp_boot_one_cpu(int cpuid)
+int __cpuinit smp_boot_one_cpu(int cpuid, struct task_struct *idle)
 {
 	const struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpuid);
-	struct task_struct *idle;
 	long timeout;
 
-	/* 
-	 * Create an idle task for this CPU.  Note the address wed* give 
-	 * to kernel_thread is irrelevant -- it's going to start
-	 * where OS_BOOT_RENDEVZ vector in SAL says to start.  But
-	 * this gets all the other task-y sort of data structures set
-	 * up like we wish.   We need to pull the just created idle task 
-	 * off the run queue and stuff it into the init_tasks[] array.  
-	 * Sheesh . . .
-	 */
-
-	idle = fork_idle(cpuid);
-	if (IS_ERR(idle))
-		panic("SMP: fork failed for CPU:%d", cpuid);
-
 	task_thread_info(idle)->cpu = cpuid;
 
 	/* Let _start know what logical CPU we're booting
@@ -397,10 +382,6 @@ int __cpuinit smp_boot_one_cpu(int cpuid)
 		udelay(100);
 		barrier();
 	}
-
-	put_task_struct(idle);
-	idle = NULL;
-
 	printk(KERN_CRIT "SMP: CPU:%d is stuck.\n", cpuid);
 	return -1;
 
@@ -452,7 +433,7 @@ void smp_cpus_done(unsigned int cpu_max)
 int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *tidle)
 {
 	if (cpu != 0 && cpu < parisc_max_cpus)
-		smp_boot_one_cpu(cpu);
+		smp_boot_one_cpu(cpu, tidle);
 
 	return cpu_online(cpu) ? 0 : -ENOSYS;
 }