diff options
Diffstat (limited to 'arch/powerpc/kernel/smp.c')
| -rw-r--r-- | arch/powerpc/kernel/smp.c | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index 2b952b5386fd..e5b133ebd8a5 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -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; |