[S390] idle: remove idle notifier chain.

The idle notifier chain consists of at most one element. So there's
no point in having a notifier chain. Remove it and directly call the
function.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

4 files changed, 16 insertions, 63 deletions

diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index 7920861109d2..85defd01d293 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -75,46 +75,19 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
         return sf->gprs[8];
 }
 
-/*
- * Need to know about CPUs going idle?
- */
-static ATOMIC_NOTIFIER_HEAD(idle_chain);
 DEFINE_PER_CPU(struct s390_idle_data, s390_idle);
 
-int register_idle_notifier(struct notifier_block *nb)
-{
-        return atomic_notifier_chain_register(&idle_chain, nb);
-}
-EXPORT_SYMBOL(register_idle_notifier);
-
-int unregister_idle_notifier(struct notifier_block *nb)
-{
-        return atomic_notifier_chain_unregister(&idle_chain, nb);
-}
-EXPORT_SYMBOL(unregister_idle_notifier);
-
 static int s390_idle_enter(void)
 {
         struct s390_idle_data *idle;
-        int nr_calls = 0;
-        void *hcpu;
-        int rc;
 
-        hcpu = (void *)(long)smp_processor_id();
-        rc = __atomic_notifier_call_chain(&idle_chain, S390_CPU_IDLE, hcpu, -1,
-                                          &nr_calls);
-        if (rc == NOTIFY_BAD) {
-                nr_calls--;
-                __atomic_notifier_call_chain(&idle_chain, S390_CPU_NOT_IDLE,
-                                             hcpu, nr_calls, NULL);
-                return rc;
-        }
         idle = &__get_cpu_var(s390_idle);
         spin_lock(&idle->lock);
         idle->idle_count++;
         idle->in_idle = 1;
         idle->idle_enter = get_clock();
         spin_unlock(&idle->lock);
+        vtime_stop_cpu_timer();
         return NOTIFY_OK;
 }
 
@@ -122,13 +95,12 @@ void s390_idle_leave(void)
 {
         struct s390_idle_data *idle;
 
+        vtime_start_cpu_timer();
         idle = &__get_cpu_var(s390_idle);
         spin_lock(&idle->lock);
         idle->idle_time += get_clock() - idle->idle_enter;
         idle->in_idle = 0;
         spin_unlock(&idle->lock);
-        atomic_notifier_call_chain(&idle_chain, S390_CPU_NOT_IDLE,
-                                   (void *)(long) smp_processor_id());
 }
 
 extern void s390_handle_mcck(void);
diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c
index ca90ee3f930e..eb08d04bc1ec 100644
--- a/arch/s390/kernel/vtime.c
+++ b/arch/s390/kernel/vtime.c
@@ -136,7 +136,7 @@ static inline void set_vtimer(__u64 expires)
 }
 #endif
 
-static void start_cpu_timer(void)
+void vtime_start_cpu_timer(void)
 {
         struct vtimer_queue *vt_list;
 
@@ -150,7 +150,7 @@ static void start_cpu_timer(void)
                 set_vtimer(vt_list->idle);
 }
 
-static void stop_cpu_timer(void)
+void vtime_stop_cpu_timer(void)
 {
         struct vtimer_queue *vt_list;
 
@@ -536,24 +536,6 @@ void init_cpu_vtimer(void)
 
 }
 
-static int vtimer_idle_notify(struct notifier_block *self,
-                              unsigned long action, void *hcpu)
-{
-        switch (action) {
-        case S390_CPU_IDLE:
-                stop_cpu_timer();
-                break;
-        case S390_CPU_NOT_IDLE:
-                start_cpu_timer();
-                break;
-        }
-        return NOTIFY_OK;
-}
-
-static struct notifier_block vtimer_idle_nb = {
-        .notifier_call = vtimer_idle_notify,
-};
-
 void __init vtime_init(void)
 {
         /* request the cpu timer external interrupt */
@@ -561,9 +543,6 @@ void __init vtime_init(void)
                                               &ext_int_info_timer) != 0)
                 panic("Couldn't request external interrupt 0x1005");
 
-        if (register_idle_notifier(&vtimer_idle_nb))
-                panic("Couldn't register idle notifier");
-
         /* Enable cpu timer interrupts on the boot cpu. */
         init_cpu_vtimer();
 }
diff --git a/include/asm-s390/processor.h b/include/asm-s390/processor.h
index 5483c28b8bc3..4af80af2a88f 100644
--- a/include/asm-s390/processor.h
+++ b/include/asm-s390/processor.h
@@ -336,16 +336,6 @@ extern void (*s390_base_mcck_handler_fn)(void);
 extern void (*s390_base_pgm_handler_fn)(void);
 extern void (*s390_base_ext_handler_fn)(void);
 
-/*
- * CPU idle notifier chain.
- */
-#define S390_CPU_IDLE           0
-#define S390_CPU_NOT_IDLE       1
-
-struct notifier_block;
-int register_idle_notifier(struct notifier_block *nb);
-int unregister_idle_notifier(struct notifier_block *nb);
-
 #define ARCH_LOW_ADDRESS_LIMIT  0x7fffffffUL
 
 #endif
diff --git a/include/asm-s390/timer.h b/include/asm-s390/timer.h
index adb34860a543..d98d79e35cd6 100644
--- a/include/asm-s390/timer.h
+++ b/include/asm-s390/timer.h
@@ -48,6 +48,18 @@ extern int del_virt_timer(struct vtimer_list *timer);
 extern void init_cpu_vtimer(void);
 extern void vtime_init(void);
 
+#ifdef CONFIG_VIRT_TIMER
+
+extern void vtime_start_cpu_timer(void);
+extern void vtime_stop_cpu_timer(void);
+
+#else
+
+static inline void vtime_start_cpu_timer(void) { }
+static inline void vtime_stop_cpu_timer(void) { }
+
+#endif /* CONFIG_VIRT_TIMER */
+
 #endif /* __KERNEL__ */
 
 #endif /* _ASM_S390_TIMER_H */