[patch 66/66] cpuhotplug: Remove CPU_STARTING and CPU_DYING notifier

[Anna-Maria Gleixner <anna-maria@linutronix.de>]

[-- Attachment #1: 0059-cpuhotplug-Remove-CPU_STARTING-notifier.patch --]
[-- Type: text/plain, Size: 6112 bytes --]

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

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
---
 arch/sparc/kernel/smp_32.c           |    2 --
 include/linux/cpu.h                  |   12 ------------
 include/linux/cpuhotplug.h           |    1 -
 kernel/cpu.c                         |   30 ++----------------------------
 tools/testing/radix-tree/linux/cpu.h |   13 -------------
 5 files changed, 2 insertions(+), 56 deletions(-)

--- a/arch/sparc/kernel/smp_32.c
+++ b/arch/sparc/kernel/smp_32.c
@@ -352,9 +352,7 @@ static void sparc_start_secondary(void *
 	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 */
--- 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;
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -69,7 +69,6 @@ enum cpuhp_state {
 	CPUHP_AP_LEDTRIG_STARTING,
 	CPUHP_AP_SMPCFD_DYING,
 	CPUHP_AP_X86_TBOOT_DYING,
-	CPUHP_AP_NOTIFY_STARTING,
 	CPUHP_AP_ONLINE,
 	CPUHP_TEARDOWN_CPU,
 	CPUHP_AP_ONLINE_IDLE,
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -331,12 +331,6 @@ static int notify_online(unsigned int cp
 	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);
@@ -668,12 +662,6 @@ static int notify_down_prepare(unsigned
 	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)
 {
@@ -728,7 +716,7 @@ 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.
 	 *
@@ -781,7 +769,6 @@ 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
@@ -871,10 +858,9 @@ 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().
  */
@@ -1264,18 +1250,6 @@ static struct cpuhp_step cpuhp_ap_states
 		.startup = NULL,
 		.teardown = rcutree_dying_cpu,
 	},
-	/*
-	 * Low level startup/teardown notifiers. Run with interrupts
-	 * disabled. Will be removed once the notifiers are converted to
-	 * states.
-	 */
-	[CPUHP_AP_NOTIFY_STARTING] = {
-		.name			= "notify:starting",
-		.startup		= notify_starting,
-		.teardown		= notify_dying,
-		.skip_onerr		= true,
-		.cant_stop		= true,
-	},
 	/* Entry state on starting. Interrupts enabled from here on. Transient
 	 * state for synchronsization */
 	[CPUHP_AP_ONLINE] = {
--- 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)