cpu/hotplug: Remove CPU_STARTING and CPU_DYING notifier

All users are converted to state machine, remove CPU_STARTING and the
corresponding CPU_DYING.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160818125731.27256-2-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

5 files changed, 2 insertions, 56 deletions

diff --git a/arch/sparc/kernel/smp_32.c b/arch/sparc/kernel/smp_32.c
index fb30e7c6a5b1..e80e6ba3d500 100644
--- a/arch/sparc/kernel/smp_32.c
+++ b/arch/sparc/kernel/smp_32.c
@@ -352,9 +352,7 @@ static void sparc_start_secondary(void *arg)
         preempt_disable();
         cpu = smp_processor_id();
 
-        /* Invoke the CPU_STARTING notifier callbacks */
         notify_cpu_starting(cpu);
-
         arch_cpu_pre_online(arg);
 
         /* Set the CPU in the cpu_online_mask */
diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index 797d9c8e9a1b..6bf1992fe638 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -61,17 +61,8 @@ struct notifier_block;
 #define CPU_DOWN_PREPARE        0x0005 /* CPU (unsigned)v going down */
 #define CPU_DOWN_FAILED         0x0006 /* CPU (unsigned)v NOT going down */
 #define CPU_DEAD                0x0007 /* CPU (unsigned)v dead */
-#define CPU_DYING               0x0008 /* CPU (unsigned)v not running any task,
-                                        * not handling interrupts, soon dead.
-                                        * Called on the dying cpu, interrupts
-                                        * are already disabled. Must not
-                                        * sleep, must not fail */
 #define CPU_POST_DEAD           0x0009 /* CPU (unsigned)v dead, cpu_hotplug
                                         * lock is dropped */
-#define CPU_STARTING            0x000A /* CPU (unsigned)v soon running.
-                                        * Called on the new cpu, just before
-                                        * enabling interrupts. Must not sleep,
-                                        * must not fail */
 #define CPU_BROKEN              0x000B /* CPU (unsigned)v did not die properly,
                                         * perhaps due to preemption. */
 
@@ -86,9 +77,6 @@ struct notifier_block;
 #define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
 #define CPU_DOWN_FAILED_FROZEN  (CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
 #define CPU_DEAD_FROZEN         (CPU_DEAD | CPU_TASKS_FROZEN)
-#define CPU_DYING_FROZEN        (CPU_DYING | CPU_TASKS_FROZEN)
-#define CPU_STARTING_FROZEN     (CPU_STARTING | CPU_TASKS_FROZEN)
-
 
 #ifdef CONFIG_SMP
 extern bool cpuhp_tasks_frozen;
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index b95f7adfbf8b..9e6d10786e29 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -69,7 +69,6 @@ enum cpuhp_state {
         CPUHP_AP_ARM64_ISNDEP_STARTING,
         CPUHP_AP_SMPCFD_DYING,
         CPUHP_AP_X86_TBOOT_DYING,
-        CPUHP_AP_NOTIFY_STARTING,
         CPUHP_AP_ONLINE,
         CPUHP_TEARDOWN_CPU,
         CPUHP_AP_ONLINE_IDLE,
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 32eef273a0b9..d14ae4438e8e 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -408,12 +408,6 @@ static int notify_online(unsigned int cpu)
         return 0;
 }
 
-static int notify_starting(unsigned int cpu)
-{
-        cpu_notify(CPU_STARTING, cpu);
-        return 0;
-}
-
 static int bringup_wait_for_ap(unsigned int cpu)
 {
         struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
@@ -759,12 +753,6 @@ static int notify_down_prepare(unsigned int cpu)
         return err;
 }
 
-static int notify_dying(unsigned int cpu)
-{
-        cpu_notify(CPU_DYING, cpu);
-        return 0;
-}
-
 /* Take this CPU down. */
 static int take_cpu_down(void *_param)
 {
@@ -823,7 +811,7 @@ static int takedown_cpu(unsigned int cpu)
         BUG_ON(cpu_online(cpu));
 
         /*
-         * The migration_call() CPU_DYING callback will have removed all
+         * The CPUHP_AP_SCHED_MIGRATE_DYING callback will have removed all
          * runnable tasks from the cpu, there's only the idle task left now
          * that the migration thread is done doing the stop_machine thing.
          *
@@ -876,7 +864,6 @@ void cpuhp_report_idle_dead(void)
 #define notify_down_prepare     NULL
 #define takedown_cpu            NULL
 #define notify_dead             NULL
-#define notify_dying            NULL
 #endif
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -966,10 +953,9 @@ EXPORT_SYMBOL(cpu_down);
 #endif /*CONFIG_HOTPLUG_CPU*/
 
 /**
- * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers
+ * notify_cpu_starting(cpu) - Invoke the callbacks on the starting CPU
  * @cpu: cpu that just started
  *
- * This function calls the cpu_chain notifiers with CPU_STARTING.
  * It must be called by the arch code on the new cpu, before the new cpu
  * enables interrupts and before the "boot" cpu returns from __cpu_up().
  */
@@ -1365,18 +1351,6 @@ static struct cpuhp_step cpuhp_ap_states[] = {
                 .startup.single         = NULL,
                 .teardown.single        = rcutree_dying_cpu,
         },
-        /*
-         * Low level startup.single/teardown notifiers. Run with interrupts
-         * disabled. Will be removed once the notifiers are converted to
-         * states.
-         */
-        [CPUHP_AP_NOTIFY_STARTING] = {
-                .name                   = "notify:starting",
-                .startup.single         = notify_starting,
-                .teardown.single                = notify_dying,
-                .skip_onerr             = true,
-                .cant_stop              = true,
-        },
         /* Entry state on starting. Interrupts enabled from here on. Transient
          * state for synchronsization */
         [CPUHP_AP_ONLINE] = {
diff --git a/tools/testing/radix-tree/linux/cpu.h b/tools/testing/radix-tree/linux/cpu.h
index 60a40459f269..7cf412103205 100644
--- a/tools/testing/radix-tree/linux/cpu.h
+++ b/tools/testing/radix-tree/linux/cpu.h
@@ -7,19 +7,8 @@
 #define CPU_DOWN_PREPARE        0x0005 /* CPU (unsigned)v going down */
 #define CPU_DOWN_FAILED         0x0006 /* CPU (unsigned)v NOT going down */
 #define CPU_DEAD                0x0007 /* CPU (unsigned)v dead */
-#define CPU_DYING               0x0008 /* CPU (unsigned)v not running any task,
-                                        * not handling interrupts, soon dead.
-                                        * Called on the dying cpu, interrupts
-                                        * are already disabled. Must not
-                                        * sleep, must not fail */
 #define CPU_POST_DEAD           0x0009 /* CPU (unsigned)v dead, cpu_hotplug
                                         * lock is dropped */
-#define CPU_STARTING            0x000A /* CPU (unsigned)v soon running.
-                                        * Called on the new cpu, just before
-                                        * enabling interrupts. Must not sleep,
-                                        * must not fail */
-#define CPU_DYING_IDLE          0x000B /* CPU (unsigned)v dying, reached
-                                        * idle loop. */
 #define CPU_BROKEN              0x000C /* CPU (unsigned)v did not die properly,
                                         * perhaps due to preemption. */
 #define CPU_TASKS_FROZEN        0x0010
@@ -30,5 +19,3 @@
 #define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
 #define CPU_DOWN_FAILED_FROZEN  (CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
 #define CPU_DEAD_FROZEN         (CPU_DEAD | CPU_TASKS_FROZEN)
-#define CPU_DYING_FROZEN        (CPU_DYING | CPU_TASKS_FROZEN)
-#define CPU_STARTING_FROZEN     (CPU_STARTING | CPU_TASKS_FROZEN)