libnvdimm, nvdimm: dimm driver and base libnvdimm device-driver infrastructure

* Implement the device-model infrastructure for loading modules and
  attaching drivers to nvdimm devices.  This is a simple association of a
  nd-device-type number with a driver that has a bitmask of supported
  device types.  To facilitate userspace bind/unbind operations 'modalias'
  and 'devtype', that also appear in the uevent, are added as generic
  sysfs attributes for all nvdimm devices.  The reason for the device-type
  number is to support sub-types within a given parent devtype, be it a
  vendor-specific sub-type or otherwise.

* The first consumer of this infrastructure is the driver
  for dimm devices.  It simply uses control messages to retrieve and
  store the configuration-data image (label set) from each dimm.

Note: nd_device_register() arranges for asynchronous registration of
      nvdimm bus devices by default.

Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Neil Brown <neilb@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/include/linux/nd.h b/include/linux/nd.h
new file mode 100644
index 0000000..e074f67
--- /dev/null
+++ b/include/linux/nd.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+#ifndef __LINUX_ND_H__
+#define __LINUX_ND_H__
+#include <linux/ndctl.h>
+#include <linux/device.h>
+
+struct nd_device_driver {
+	struct device_driver drv;
+	unsigned long type;
+	int (*probe)(struct device *dev);
+	int (*remove)(struct device *dev);
+};
+
+static inline struct nd_device_driver *to_nd_device_driver(
+		struct device_driver *drv)
+{
+	return container_of(drv, struct nd_device_driver, drv);
+}
+
+#define MODULE_ALIAS_ND_DEVICE(type) \
+	MODULE_ALIAS("nd:t" __stringify(type) "*")
+#define ND_DEVICE_MODALIAS_FMT "nd:t%d"
+
+int __must_check __nd_driver_register(struct nd_device_driver *nd_drv,
+		struct module *module, const char *mod_name);
+#define nd_driver_register(driver) \
+	__nd_driver_register(driver, THIS_MODULE, KBUILD_MODNAME)
+#endif /* __LINUX_ND_H__ */