1 files changed, 50 insertions, 4 deletions

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 2b952b5386fd..793401e65088 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -82,7 +82,7 @@ int smt_enabled_at_boot = 1;
 static void (*crash_ipi_function_ptr)(struct pt_regs *) = NULL;
 
 #ifdef CONFIG_PPC64
-int __devinit smp_generic_kick_cpu(int nr)
+int smp_generic_kick_cpu(int nr)
 {
         BUG_ON(nr < 0 || nr >= NR_CPUS);
 
@@ -311,7 +311,7 @@ void smp_send_stop(void)
 
 struct thread_info *current_set[NR_CPUS];
 
-static void __devinit smp_store_cpu_info(int id)
+static void smp_store_cpu_info(int id)
 {
         per_cpu(cpu_pvr, id) = mfspr(SPRN_PVR);
 #ifdef CONFIG_PPC_FSL_BOOK3E
@@ -355,7 +355,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
                 max_cpus = 1;
 }
 
-void __devinit smp_prepare_boot_cpu(void)
+void smp_prepare_boot_cpu(void)
 {
         BUG_ON(smp_processor_id() != boot_cpuid);
 #ifdef CONFIG_PPC64
@@ -427,6 +427,45 @@ int generic_check_cpu_restart(unsigned int cpu)
 {
         return per_cpu(cpu_state, cpu) == CPU_UP_PREPARE;
 }
+
+static atomic_t secondary_inhibit_count;
+
+/*
+ * Don't allow secondary CPU threads to come online
+ */
+void inhibit_secondary_onlining(void)
+{
+        /*
+         * This makes secondary_inhibit_count stable during cpu
+         * online/offline operations.
+         */
+        get_online_cpus();
+
+        atomic_inc(&secondary_inhibit_count);
+        put_online_cpus();
+}
+EXPORT_SYMBOL_GPL(inhibit_secondary_onlining);
+
+/*
+ * Allow secondary CPU threads to come online again
+ */
+void uninhibit_secondary_onlining(void)
+{
+        get_online_cpus();
+        atomic_dec(&secondary_inhibit_count);
+        put_online_cpus();
+}
+EXPORT_SYMBOL_GPL(uninhibit_secondary_onlining);
+
+static int secondaries_inhibited(void)
+{
+        return atomic_read(&secondary_inhibit_count);
+}
+
+#else /* HOTPLUG_CPU */
+
+#define secondaries_inhibited()         0
+
 #endif
 
 static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle)
@@ -445,6 +484,13 @@ int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *tidle)
 {
         int rc, c;
 
+        /*
+         * Don't allow secondary threads to come online if inhibited
+         */
+        if (threads_per_core > 1 && secondaries_inhibited() &&
+            cpu % threads_per_core != 0)
+                return -EBUSY;
+
         if (smp_ops == NULL ||
             (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)))
                 return -EINVAL;
@@ -564,7 +610,7 @@ static struct device_node *cpu_to_l2cache(int cpu)
 }
 
 /* Activate a secondary processor. */
-void __devinit start_secondary(void *unused)
+void start_secondary(void *unused)
 {
         unsigned int cpu = smp_processor_id();
         struct device_node *l2_cache;