powerpc: pSeries reconfig notifier error injection module

This provides the ability to inject artifical errors to pSeries reconfig
notifier chain callbacks.  It is controlled through debugfs interface
under /sys/kernel/debug/notifier-error-inject/pSeries-reconfig

If the notifier call chain should be failed with some events
notified, write the error code to "actions/<notifier event>/error".
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Greg KH <greg@kroah.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Dave Jones <davej@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

lib/Kconfig.debug

@@ -1166,6 +1166,23 @@ config MEMORY_NOTIFIER_ERROR_INJECT
 
 	  If unsure, say N.
 
+config PSERIES_RECONFIG_NOTIFIER_ERROR_INJECT
+	tristate "pSeries reconfig notifier error injection module"
+	depends on PPC_PSERIES && NOTIFIER_ERROR_INJECTION
+	help
+	  This option provides the ability to inject artifical errors to
+	  pSeries reconfig notifier chain callbacks.  It is controlled
+	  through debugfs interface under
+	  /sys/kernel/debug/notifier-error-inject/pSeries-reconfig/
+
+	  If the notifier call chain should be failed with some events
+	  notified, write the error code to "actions/<notifier event>/error".
+
+	  To compile this code as a module, choose M here: the module will
+	  be called memory-notifier-error-inject.
+
+	  If unsure, say N.
+
 config FAULT_INJECTION
 	bool "Fault-injection framework"
 	depends on DEBUG_KERNEL

lib/Makefile

@@ -94,6 +94,8 @@ 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_MEMORY_NOTIFIER_ERROR_INJECT) += memory-notifier-error-inject.o
+obj-$(CONFIG_PSERIES_RECONFIG_NOTIFIER_ERROR_INJECT) += \
+	pSeries-reconfig-notifier-error-inject.o
 
 lib-$(CONFIG_GENERIC_BUG) += bug.o
 

lib/pSeries-reconfig-notifier-error-inject.c

+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include <asm/pSeries_reconfig.h>
+
+#include "notifier-error-inject.h"
+
+static int priority;
+module_param(priority, int, 0);
+MODULE_PARM_DESC(priority, "specify pSeries reconfig notifier priority");
+
+static struct notifier_err_inject reconfig_err_inject = {
+	.actions = {
+		{ NOTIFIER_ERR_INJECT_ACTION(PSERIES_RECONFIG_ADD) },
+		{ NOTIFIER_ERR_INJECT_ACTION(PSERIES_RECONFIG_REMOVE) },
+		{ NOTIFIER_ERR_INJECT_ACTION(PSERIES_DRCONF_MEM_ADD) },
+		{ NOTIFIER_ERR_INJECT_ACTION(PSERIES_DRCONF_MEM_REMOVE) },
+		{}
+	}
+};
+
+static struct dentry *dir;
+
+static int err_inject_init(void)
+{
+	int err;
+
+	dir = notifier_err_inject_init("pSeries-reconfig",
+		notifier_err_inject_dir, &reconfig_err_inject, priority);
+	if (IS_ERR(dir))
+		return PTR_ERR(dir);
+
+	err = pSeries_reconfig_notifier_register(&reconfig_err_inject.nb);
+	if (err)
+		debugfs_remove_recursive(dir);
+
+	return err;
+}
+
+static void err_inject_exit(void)
+{
+	pSeries_reconfig_notifier_unregister(&reconfig_err_inject.nb);
+	debugfs_remove_recursive(dir);
+}
+
+module_init(err_inject_init);
+module_exit(err_inject_exit);
+
+MODULE_DESCRIPTION("pSeries reconfig notifier error injection module");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");