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: Akinobu 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 51 insertions, 0 deletions

diff --git a/lib/pSeries-reconfig-notifier-error-inject.c b/lib/pSeries-reconfig-notifier-error-inject.c
new file mode 100644
index 000000000000..7f7c98dcd5c4
--- /dev/null
+++ b/lib/pSeries-reconfig-notifier-error-inject.c
@@ -0,0 +1,51 @@
+#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>");