1 files changed, 67 insertions, 82 deletions

diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index 2d3f5c504939..2ece3aa5069c 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -90,8 +90,18 @@ struct tvec_base {
         struct tvec tv5;
 } ____cacheline_aligned;
 
+/*
+ * __TIMER_INITIALIZER() needs to set ->base to a valid pointer (because we've
+ * made NULL special, hint: lock_timer_base()) and we cannot get a compile time
+ * pointer to per-cpu entries because we don't know where we'll map the section,
+ * even for the boot cpu.
+ *
+ * And so we use boot_tvec_bases for boot CPU and per-cpu __tvec_bases for the
+ * rest of them.
+ */
 struct tvec_base boot_tvec_bases;
 EXPORT_SYMBOL(boot_tvec_bases);
+
 static DEFINE_PER_CPU(struct tvec_base *, tvec_bases) = &boot_tvec_bases;
 
 /* Functions below help us manage 'deferrable' flag */
@@ -1027,6 +1037,8 @@ int try_to_del_timer_sync(struct timer_list *timer)
 EXPORT_SYMBOL(try_to_del_timer_sync);
 
 #ifdef CONFIG_SMP
+static DEFINE_PER_CPU(struct tvec_base, __tvec_bases);
+
 /**
  * del_timer_sync - deactivate a timer and wait for the handler to finish.
  * @timer: the timer to be deactivated
@@ -1532,64 +1544,6 @@ signed long __sched schedule_timeout_uninterruptible(signed long timeout)
 }
 EXPORT_SYMBOL(schedule_timeout_uninterruptible);
 
-static int init_timers_cpu(int cpu)
-{
-        int j;
-        struct tvec_base *base;
-        static char tvec_base_done[NR_CPUS];
-
-        if (!tvec_base_done[cpu]) {
-                static char boot_done;
-
-                if (boot_done) {
-                        /*
-                         * The APs use this path later in boot
-                         */
-                        base = kzalloc_node(sizeof(*base), GFP_KERNEL,
-                                            cpu_to_node(cpu));
-                        if (!base)
-                                return -ENOMEM;
-
-                        /* Make sure tvec_base has TIMER_FLAG_MASK bits free */
-                        if (WARN_ON(base != tbase_get_base(base))) {
-                                kfree(base);
-                                return -ENOMEM;
-                        }
-                        per_cpu(tvec_bases, cpu) = base;
-                } else {
-                        /*
-                         * This is for the boot CPU - we use compile-time
-                         * static initialisation because per-cpu memory isn't
-                         * ready yet and because the memory allocators are not
-                         * initialised either.
-                         */
-                        boot_done = 1;
-                        base = &boot_tvec_bases;
-                }
-                spin_lock_init(&base->lock);
-                tvec_base_done[cpu] = 1;
-                base->cpu = cpu;
-        } else {
-                base = per_cpu(tvec_bases, cpu);
-        }
-
-
-        for (j = 0; j < TVN_SIZE; j++) {
-                INIT_LIST_HEAD(base->tv5.vec + j);
-                INIT_LIST_HEAD(base->tv4.vec + j);
-                INIT_LIST_HEAD(base->tv3.vec + j);
-                INIT_LIST_HEAD(base->tv2.vec + j);
-        }
-        for (j = 0; j < TVR_SIZE; j++)
-                INIT_LIST_HEAD(base->tv1.vec + j);
-
-        base->timer_jiffies = jiffies;
-        base->next_timer = base->timer_jiffies;
-        base->active_timers = 0;
-        base->all_timers = 0;
-        return 0;
-}
-
 #ifdef CONFIG_HOTPLUG_CPU
 static void migrate_timer_list(struct tvec_base *new_base, struct list_head *head)
 {
@@ -1631,55 +1585,86 @@ static void migrate_timers(int cpu)
                 migrate_timer_list(new_base, old_base->tv5.vec + i);
         }
 
+        old_base->active_timers = 0;
+        old_base->all_timers = 0;
+
         spin_unlock(&old_base->lock);
         spin_unlock_irq(&new_base->lock);
         put_cpu_var(tvec_bases);
 }
-#endif /* CONFIG_HOTPLUG_CPU */
 
 static int timer_cpu_notify(struct notifier_block *self,
                                 unsigned long action, void *hcpu)
 {
-        long cpu = (long)hcpu;
-        int err;
-
-        switch(action) {
-        case CPU_UP_PREPARE:
-        case CPU_UP_PREPARE_FROZEN:
-                err = init_timers_cpu(cpu);
-                if (err < 0)
-                        return notifier_from_errno(err);
-                break;
-#ifdef CONFIG_HOTPLUG_CPU
+        switch (action) {
         case CPU_DEAD:
         case CPU_DEAD_FROZEN:
-                migrate_timers(cpu);
+                migrate_timers((long)hcpu);
                 break;
-#endif
         default:
                 break;
         }
+
         return NOTIFY_OK;
 }
 
-static struct notifier_block timers_nb = {
-        .notifier_call  = timer_cpu_notify,
-};
+static inline void timer_register_cpu_notifier(void)
+{
+        cpu_notifier(timer_cpu_notify, 0);
+}
+#else
+static inline void timer_register_cpu_notifier(void) { }
+#endif /* CONFIG_HOTPLUG_CPU */
 
+static void __init init_timer_cpu(struct tvec_base *base, int cpu)
+{
+        int j;
 
-void __init init_timers(void)
+        BUG_ON(base != tbase_get_base(base));
+
+        base->cpu = cpu;
+        per_cpu(tvec_bases, cpu) = base;
+        spin_lock_init(&base->lock);
+
+        for (j = 0; j < TVN_SIZE; j++) {
+                INIT_LIST_HEAD(base->tv5.vec + j);
+                INIT_LIST_HEAD(base->tv4.vec + j);
+                INIT_LIST_HEAD(base->tv3.vec + j);
+                INIT_LIST_HEAD(base->tv2.vec + j);
+        }
+        for (j = 0; j < TVR_SIZE; j++)
+                INIT_LIST_HEAD(base->tv1.vec + j);
+
+        base->timer_jiffies = jiffies;
+        base->next_timer = base->timer_jiffies;
+}
+
+static void __init init_timer_cpus(void)
 {
-        int err;
+        struct tvec_base *base;
+        int local_cpu = smp_processor_id();
+        int cpu;
 
+        for_each_possible_cpu(cpu) {
+                if (cpu == local_cpu)
+                        base = &boot_tvec_bases;
+#ifdef CONFIG_SMP
+                else
+                        base = per_cpu_ptr(&__tvec_bases, cpu);
+#endif
+
+                init_timer_cpu(base, cpu);
+        }
+}
+
+void __init init_timers(void)
+{
         /* ensure there are enough low bits for flags in timer->base pointer */
         BUILD_BUG_ON(__alignof__(struct tvec_base) & TIMER_FLAG_MASK);
 
-        err = timer_cpu_notify(&timers_nb, (unsigned long)CPU_UP_PREPARE,
-                               (void *)(long)smp_processor_id());
-        BUG_ON(err != NOTIFY_OK);
-
+        init_timer_cpus();
         init_timer_stats();
-        register_cpu_notifier(&timers_nb);
+        timer_register_cpu_notifier();
         open_softirq(TIMER_SOFTIRQ, run_timer_softirq);
 }