Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild

[cascardo/linux.git] / kernel / stop_machine.c

diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index fd643d8..12484e5 100644 (file)
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -35,13 +35,16 @@ struct cpu_stop_done {
 
 /* the actual stopper, one per every possible cpu, enabled on online cpus */
 struct cpu_stopper {
+       struct task_struct      *thread;
+
        spinlock_t              lock;
        bool                    enabled;        /* is this stopper enabled? */
        struct list_head        works;          /* list of pending works */
+
+       struct cpu_stop_work    stop_work;      /* for stop_cpus */
 };
 
 static DEFINE_PER_CPU(struct cpu_stopper, cpu_stopper);
-static DEFINE_PER_CPU(struct task_struct *, cpu_stopper_task);
 static bool stop_machine_initialized = false;
 
 /*
@@ -74,7 +77,6 @@ static void cpu_stop_signal_done(struct cpu_stop_done *done, bool executed)
 static void cpu_stop_queue_work(unsigned int cpu, struct cpu_stop_work *work)
 {
        struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);
-       struct task_struct *p = per_cpu(cpu_stopper_task, cpu);
 
        unsigned long flags;
 
@@ -82,7 +84,7 @@ static void cpu_stop_queue_work(unsigned int cpu, struct cpu_stop_work *work)
 
        if (stopper->enabled) {
                list_add_tail(&work->list, &stopper->works);
-               wake_up_process(p);
+               wake_up_process(stopper->thread);
        } else
                cpu_stop_signal_done(work->done, false);
 
@@ -139,7 +141,7 @@ enum multi_stop_state {
 };
 
 struct multi_stop_data {
-       int                     (*fn)(void *);
+       cpu_stop_fn_t           fn;
        void                    *data;
        /* Like num_online_cpus(), but hotplug cpu uses us, so we need this. */
        unsigned int            num_threads;
@@ -293,7 +295,6 @@ void stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg,
 
 /* static data for stop_cpus */
 static DEFINE_MUTEX(stop_cpus_mutex);
-static DEFINE_PER_CPU(struct cpu_stop_work, stop_cpus_work);
 
 static void queue_stop_cpus_work(const struct cpumask *cpumask,
                                 cpu_stop_fn_t fn, void *arg,
@@ -302,22 +303,19 @@ static void queue_stop_cpus_work(const struct cpumask *cpumask,
        struct cpu_stop_work *work;
        unsigned int cpu;
 
-       /* initialize works and done */
-       for_each_cpu(cpu, cpumask) {
-               work = &per_cpu(stop_cpus_work, cpu);
-               work->fn = fn;
-               work->arg = arg;
-               work->done = done;
-       }
-
        /*
         * Disable preemption while queueing to avoid getting
         * preempted by a stopper which might wait for other stoppers
         * to enter @fn which can lead to deadlock.
         */
        lg_global_lock(&stop_cpus_lock);
-       for_each_cpu(cpu, cpumask)
-               cpu_stop_queue_work(cpu, &per_cpu(stop_cpus_work, cpu));
+       for_each_cpu(cpu, cpumask) {
+               work = &per_cpu(cpu_stopper.stop_work, cpu);
+               work->fn = fn;
+               work->arg = arg;
+               work->done = done;
+               cpu_stop_queue_work(cpu, work);
+       }
        lg_global_unlock(&stop_cpus_lock);
 }
 
@@ -458,19 +456,21 @@ extern void sched_set_stop_task(int cpu, struct task_struct *stop);
 
 static void cpu_stop_create(unsigned int cpu)
 {
-       sched_set_stop_task(cpu, per_cpu(cpu_stopper_task, cpu));
+       sched_set_stop_task(cpu, per_cpu(cpu_stopper.thread, cpu));
 }
 
 static void cpu_stop_park(unsigned int cpu)
 {
        struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);
-       struct cpu_stop_work *work;
+       struct cpu_stop_work *work, *tmp;
        unsigned long flags;
 
        /* drain remaining works */
        spin_lock_irqsave(&stopper->lock, flags);
-       list_for_each_entry(work, &stopper->works, list)
+       list_for_each_entry_safe(work, tmp, &stopper->works, list) {
+               list_del_init(&work->list);
                cpu_stop_signal_done(work->done, false);
+       }
        stopper->enabled = false;
        spin_unlock_irqrestore(&stopper->lock, flags);
 }
@@ -485,7 +485,7 @@ static void cpu_stop_unpark(unsigned int cpu)
 }
 
 static struct smp_hotplug_thread cpu_stop_threads = {
-       .store                  = &cpu_stopper_task,
+       .store                  = &cpu_stopper.thread,
        .thread_should_run      = cpu_stop_should_run,
        .thread_fn              = cpu_stopper_thread,
        .thread_comm            = "migration/%u",
@@ -515,7 +515,7 @@ early_initcall(cpu_stop_init);
 
 #ifdef CONFIG_STOP_MACHINE
 
-int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus)
+static int __stop_machine(cpu_stop_fn_t fn, void *data, const struct cpumask *cpus)
 {
        struct multi_stop_data msdata = {
                .fn = fn,
@@ -548,7 +548,7 @@ int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus)
        return stop_cpus(cpu_online_mask, multi_cpu_stop, &msdata);
 }
 
-int stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus)
+int stop_machine(cpu_stop_fn_t fn, void *data, const struct cpumask *cpus)
 {
        int ret;
 
@@ -582,7 +582,7 @@ EXPORT_SYMBOL_GPL(stop_machine);
  * 0 if all executions of @fn returned 0, any non zero return value if any
  * returned non zero.
  */
-int stop_machine_from_inactive_cpu(int (*fn)(void *), void *data,
+int stop_machine_from_inactive_cpu(cpu_stop_fn_t fn, void *data,
                                  const struct cpumask *cpus)
 {
        struct multi_stop_data msdata = { .fn = fn, .data = data,