powerpc: 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: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Link: http://lkml.kernel.org/r/20120420124557.311212868@linutronix.de
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index feab3ba..c815535 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -144,6 +144,7 @@
select HAVE_BPF_JIT if (PPC64 && NET)
select HAVE_ARCH_JUMP_LABEL
select ARCH_HAVE_NMI_SAFE_CMPXCHG
+ select GENERIC_SMP_IDLE_THREAD
config EARLY_PRINTK
bool
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index d38030f..e4cb343 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -57,27 +57,9 @@
#define DBG(fmt...)
#endif
-
-/* Store all idle threads, this can be reused instead of creating
-* a new thread. Also avoids complicated thread destroy functionality
-* for idle threads.
-*/
#ifdef CONFIG_HOTPLUG_CPU
-/*
- * Needed only for CONFIG_HOTPLUG_CPU because __cpuinitdata is
- * removed after init for !CONFIG_HOTPLUG_CPU.
- */
-static DEFINE_PER_CPU(struct task_struct *, idle_thread_array);
-#define get_idle_for_cpu(x) (per_cpu(idle_thread_array, x))
-#define set_idle_for_cpu(x, p) (per_cpu(idle_thread_array, x) = (p))
-
/* State of each CPU during hotplug phases */
static DEFINE_PER_CPU(int, cpu_state) = { 0 };
-
-#else
-static struct task_struct *idle_thread_array[NR_CPUS] __cpuinitdata ;
-#define get_idle_for_cpu(x) (idle_thread_array[(x)])
-#define set_idle_for_cpu(x, p) (idle_thread_array[(x)] = (p))
#endif
struct thread_info *secondary_ti;
@@ -429,57 +411,16 @@
}
#endif
-struct create_idle {
- struct work_struct work;
- struct task_struct *idle;
- struct completion done;
- int cpu;
-};
-
-static void __cpuinit do_fork_idle(struct work_struct *work)
+static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle)
{
- struct create_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 create_idle(unsigned int cpu)
-{
- struct thread_info *ti;
- struct create_idle c_idle = {
- .cpu = cpu,
- .done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done),
- };
- INIT_WORK_ONSTACK(&c_idle.work, do_fork_idle);
-
- c_idle.idle = get_idle_for_cpu(cpu);
-
- /* We can't use kernel_thread since we must avoid to
- * reschedule the child. We use a workqueue because
- * we want to fork from a kernel thread, not whatever
- * userspace process happens to be trying to online us.
- */
- if (!c_idle.idle) {
- schedule_work(&c_idle.work);
- wait_for_completion(&c_idle.done);
- } else
- init_idle(c_idle.idle, cpu);
- if (IS_ERR(c_idle.idle)) {
- pr_err("Failed fork for CPU %u: %li", cpu, PTR_ERR(c_idle.idle));
- return PTR_ERR(c_idle.idle);
- }
- ti = task_thread_info(c_idle.idle);
+ struct thread_info *ti = task_thread_info(idle);
#ifdef CONFIG_PPC64
- paca[cpu].__current = c_idle.idle;
+ paca[cpu].__current = idle;
paca[cpu].kstack = (unsigned long)ti + THREAD_SIZE - STACK_FRAME_OVERHEAD;
#endif
ti->cpu = cpu;
- current_set[cpu] = ti;
-
- return 0;
+ secondary_ti = current_set[cpu] = ti;
}
int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *tidle)
@@ -490,12 +431,7 @@
(smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)))
return -EINVAL;
- /* Make sure we have an idle thread */
- rc = create_idle(cpu);
- if (rc)
- return rc;
-
- secondary_ti = current_set[cpu];
+ cpu_idle_thread_init(cpu, tidle);
/* Make sure callin-map entry is 0 (can be leftover a CPU
* hotplug