diff options
Diffstat (limited to 'kernel/stop_machine.c')
| -rw-r--r-- | kernel/stop_machine.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index ba5070ce576..2f194e96571 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -12,7 +12,7 @@ #include <linux/cpu.h> #include <linux/init.h> #include <linux/kthread.h> -#include <linux/module.h> +#include <linux/export.h> #include <linux/percpu.h> #include <linux/sched.h> #include <linux/stop_machine.h> @@ -41,6 +41,7 @@ struct cpu_stopper { }; static DEFINE_PER_CPU(struct cpu_stopper, cpu_stopper); +static bool stop_machine_initialized = false; static void cpu_stop_init_done(struct cpu_stop_done *done, unsigned int nr_todo) { @@ -386,6 +387,8 @@ static int __init cpu_stop_init(void) cpu_stop_cpu_callback(&cpu_stop_cpu_notifier, CPU_ONLINE, bcpu); register_cpu_notifier(&cpu_stop_cpu_notifier); + stop_machine_initialized = true; + return 0; } early_initcall(cpu_stop_init); @@ -485,6 +488,25 @@ int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus) .num_threads = num_online_cpus(), .active_cpus = cpus }; + if (!stop_machine_initialized) { + /* + * Handle the case where stop_machine() is called + * early in boot before stop_machine() has been + * initialized. + */ + unsigned long flags; + int ret; + + WARN_ON_ONCE(smdata.num_threads != 1); + + local_irq_save(flags); + hard_irq_disable(); + ret = (*fn)(data); + local_irq_restore(flags); + + return ret; + } + /* Set the initial state and stop all online cpus. */ set_state(&smdata, STOPMACHINE_PREPARE); return stop_cpus(cpu_online_mask, stop_machine_cpu_stop, &smdata); |