[PATCH 5/5] s390: Use common fork_idle_from_wq in smpboot

[Venkatesh Pallipadi <venki@google.com>]

Cleanup. Instead of reimplementing fork_idle on wq and idle task caching,
use fork_idle_from_wq().

Signed-off-by: Venkatesh Pallipadi <venki@google.com>
---
 arch/s390/kernel/smp.c |   38 +++++---------------------------------
 1 files changed, 5 insertions(+), 33 deletions(-)

diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 2398ce6..7255a57 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -58,8 +58,6 @@
 /* logical cpu to cpu address */
 unsigned short __cpu_logical_map[NR_CPUS];
 
-static struct task_struct *current_set[NR_CPUS];
-
 static u8 smp_cpu_type;
 static int smp_use_sigp_detection;
 
@@ -562,22 +560,6 @@ int __cpuinit start_secondary(void *cpuvoid)
 	return 0;
 }
 
-struct create_idle {
-	struct work_struct work;
-	struct task_struct *idle;
-	struct completion done;
-	int cpu;
-};
-
-static void __cpuinit smp_fork_idle(struct work_struct *work)
-{
-	struct create_idle *c_idle;
-
-	c_idle = container_of(work, struct create_idle, work);
-	c_idle->idle = fork_idle(c_idle->cpu);
-	complete(&c_idle->done);
-}
-
 static int __cpuinit smp_alloc_lowcore(int cpu)
 {
 	unsigned long async_stack, panic_stack;
@@ -644,7 +626,6 @@ static void smp_free_lowcore(int cpu)
 int __cpuinit __cpu_up(unsigned int cpu)
 {
 	struct _lowcore *cpu_lowcore;
-	struct create_idle c_idle;
 	struct task_struct *idle;
 	struct stack_frame *sf;
 	u32 lowcore;
@@ -652,19 +633,11 @@ int __cpuinit __cpu_up(unsigned int cpu)
 
 	if (smp_cpu_state[cpu] != CPU_STATE_CONFIGURED)
 		return -EIO;
-	idle = current_set[cpu];
-	if (!idle) {
-		c_idle.done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done);
-		INIT_WORK_ONSTACK(&c_idle.work, smp_fork_idle);
-		c_idle.cpu = cpu;
-		schedule_work(&c_idle.work);
-		wait_for_completion(&c_idle.done);
-		if (IS_ERR(c_idle.idle))
-			return PTR_ERR(c_idle.idle);
-		idle = c_idle.idle;
-		current_set[cpu] = c_idle.idle;
-	}
-	init_idle(idle, cpu);
+
+	idle = fork_idle_from_wq(cpu);
+	if (IS_ERR(idle))
+		return PTR_ERR(idle);
+
 	if (smp_alloc_lowcore(cpu))
 		return -ENOMEM;
 	do {
@@ -836,7 +809,6 @@ void __init smp_prepare_boot_cpu(void)
 	set_cpu_present(0, true);
 	set_cpu_online(0, true);
 	S390_lowcore.percpu_offset = __per_cpu_offset[0];
-	current_set[0] = current;
 	smp_cpu_state[0] = CPU_STATE_CONFIGURED;
 	cpu_set_polarization(0, POLARIZATION_UNKNOWN);
 }
-- 
1.7.7.3