cpu/hotplug: Remove obsolete cpu hotplug register/unregister functions

hotcpu_notifier(), cpu_notifier(), __hotcpu_notifier(), __cpu_notifier(),
register_hotcpu_notifier(), register_cpu_notifier(),
__register_hotcpu_notifier(), __register_cpu_notifier(),
unregister_hotcpu_notifier(), unregister_cpu_notifier(),
__unregister_hotcpu_notifier(), __unregister_cpu_notifier()

are unused now. Remove them and all related code.

Remove also the now pointless cpu notifier error injection mechanism. The
states can be executed step by step and error rollback is the same as cpu
down, so any state transition can be tested w/o requiring the notifier
error injection.

Some CPU hotplug states are kept as they are (ab)used for hotplug state
tracking.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20161221192112.005642358@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

3 files changed, 0 insertions, 109 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index cb66a4648840..b06848a104e6 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1538,30 +1538,6 @@ config NOTIFIER_ERROR_INJECTION
 
 	  Say N if unsure.
 
-config CPU_NOTIFIER_ERROR_INJECT
-	tristate "CPU notifier error injection module"
-	depends on HOTPLUG_CPU && NOTIFIER_ERROR_INJECTION
-	help
-	  This option provides a kernel module that can be used to test
-	  the error handling of the cpu notifiers by injecting artificial
-	  errors to CPU notifier chain callbacks.  It is controlled through
-	  debugfs interface under /sys/kernel/debug/notifier-error-inject/cpu
-
-	  If the notifier call chain should be failed with some events
-	  notified, write the error code to "actions/<notifier event>/error".
-
-	  Example: Inject CPU offline error (-1 == -EPERM)
-
-	  # cd /sys/kernel/debug/notifier-error-inject/cpu
-	  # echo -1 > actions/CPU_DOWN_PREPARE/error
-	  # echo 0 > /sys/devices/system/cpu/cpu1/online
-	  bash: echo: write error: Operation not permitted
-
-	  To compile this code as a module, choose M here: the module will
-	  be called cpu-notifier-error-inject.
-
-	  If unsure, say N.
-
 config PM_NOTIFIER_ERROR_INJECT
 	tristate "PM notifier error injection module"
 	depends on PM && NOTIFIER_ERROR_INJECTION
diff --git a/lib/Makefile b/lib/Makefile
index 50144a3aeebd..bc4073a8cd08 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -128,7 +128,6 @@ obj-$(CONFIG_SWIOTLB) += swiotlb.o
 obj-$(CONFIG_IOMMU_HELPER) += iommu-helper.o iommu-common.o
 obj-$(CONFIG_FAULT_INJECTION) += fault-inject.o
 obj-$(CONFIG_NOTIFIER_ERROR_INJECTION) += notifier-error-inject.o
-obj-$(CONFIG_CPU_NOTIFIER_ERROR_INJECT) += cpu-notifier-error-inject.o
 obj-$(CONFIG_PM_NOTIFIER_ERROR_INJECT) += pm-notifier-error-inject.o
 obj-$(CONFIG_NETDEV_NOTIFIER_ERROR_INJECT) += netdev-notifier-error-inject.o
 obj-$(CONFIG_MEMORY_NOTIFIER_ERROR_INJECT) += memory-notifier-error-inject.o
diff --git a/lib/cpu-notifier-error-inject.c b/lib/cpu-notifier-error-inject.c
deleted file mode 100644
index 0e2c9a1e958a..000000000000
--- a/lib/cpu-notifier-error-inject.c
+++ /dev/null
@@ -1,84 +0,0 @@
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/cpu.h>
-
-#include "notifier-error-inject.h"
-
-static int priority;
-module_param(priority, int, 0);
-MODULE_PARM_DESC(priority, "specify cpu notifier priority");
-
-#define UP_PREPARE 0
-#define UP_PREPARE_FROZEN 0
-#define DOWN_PREPARE 0
-#define DOWN_PREPARE_FROZEN 0
-
-static struct notifier_err_inject cpu_notifier_err_inject = {
-	.actions = {
-		{ NOTIFIER_ERR_INJECT_ACTION(UP_PREPARE) },
-		{ NOTIFIER_ERR_INJECT_ACTION(UP_PREPARE_FROZEN) },
-		{ NOTIFIER_ERR_INJECT_ACTION(DOWN_PREPARE) },
-		{ NOTIFIER_ERR_INJECT_ACTION(DOWN_PREPARE_FROZEN) },
-		{}
-	}
-};
-
-static int notf_err_handle(struct notifier_err_inject_action *action)
-{
-	int ret;
-
-	ret = action->error;
-	if (ret)
-		pr_info("Injecting error (%d) to %s\n", ret, action->name);
-	return ret;
-}
-
-static int notf_err_inj_up_prepare(unsigned int cpu)
-{
-	if (!cpuhp_tasks_frozen)
-		return notf_err_handle(&cpu_notifier_err_inject.actions[0]);
-	else
-		return notf_err_handle(&cpu_notifier_err_inject.actions[1]);
-}
-
-static int notf_err_inj_dead(unsigned int cpu)
-{
-	if (!cpuhp_tasks_frozen)
-		return notf_err_handle(&cpu_notifier_err_inject.actions[2]);
-	else
-		return notf_err_handle(&cpu_notifier_err_inject.actions[3]);
-}
-
-static struct dentry *dir;
-
-static int err_inject_init(void)
-{
-	int err;
-
-	dir = notifier_err_inject_init("cpu", notifier_err_inject_dir,
-					&cpu_notifier_err_inject, priority);
-	if (IS_ERR(dir))
-		return PTR_ERR(dir);
-
-	err = cpuhp_setup_state_nocalls(CPUHP_NOTF_ERR_INJ_PREPARE,
-					"cpu-err-notif:prepare",
-					notf_err_inj_up_prepare,
-					notf_err_inj_dead);
-	if (err)
-		debugfs_remove_recursive(dir);
-
-	return err;
-}
-
-static void err_inject_exit(void)
-{
-	cpuhp_remove_state_nocalls(CPUHP_NOTF_ERR_INJ_PREPARE);
-	debugfs_remove_recursive(dir);
-}
-
-module_init(err_inject_init);
-module_exit(err_inject_exit);
-
-MODULE_DESCRIPTION("CPU notifier error injection module");
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");