libnvdimm: pmem label sets and namespace instantiation.

A complete label set is a PMEM-label per-dimm per-interleave-set where
all the UUIDs match and the interleave set cookie matches the hosting
interleave set.

Present sysfs attributes for manipulation of a PMEM-namespace's
'alt_name', 'uuid', and 'size' attributes.  A later patch will make
these settings persistent by writing back the label.

Note that PMEM allocations grow forwards from the start of an interleave
set (lowest dimm-physical-address (DPA)).  BLK-namespaces that alias
with a PMEM interleave set will grow allocations backward from the
highest DPA.

Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Neil Brown <neilb@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/include/linux/nd.h b/include/linux/nd.h
index da70e9962197..255c38a83083 100644
--- a/include/linux/nd.h
+++ b/include/linux/nd.h
@@ -28,16 +28,40 @@ static inline struct nd_device_driver *to_nd_device_driver(
 	return container_of(drv, struct nd_device_driver, drv);
 };
 
+/**
+ * struct nd_namespace_io - infrastructure for loading an nd_pmem instance
+ * @dev: namespace device created by the nd region driver
+ * @res: struct resource conversion of a NFIT SPA table
+ */
 struct nd_namespace_io {
 	struct device dev;
 	struct resource res;
 };
 
+/**
+ * struct nd_namespace_pmem - namespace device for dimm-backed interleaved memory
+ * @nsio: device and system physical address range to drive
+ * @alt_name: namespace name supplied in the dimm label
+ * @uuid: namespace name supplied in the dimm label
+ */
+struct nd_namespace_pmem {
+	struct nd_namespace_io nsio;
+	char *alt_name;
+	u8 *uuid;
+};
+
 static inline struct nd_namespace_io *to_nd_namespace_io(struct device *dev)
 {
 	return container_of(dev, struct nd_namespace_io, dev);
 }
 
+static inline struct nd_namespace_pmem *to_nd_namespace_pmem(struct device *dev)
+{
+	struct nd_namespace_io *nsio = to_nd_namespace_io(dev);
+
+	return container_of(nsio, struct nd_namespace_pmem, nsio);
+}
+
 #define MODULE_ALIAS_ND_DEVICE(type) \
 	MODULE_ALIAS("nd:t" __stringify(type) "*")
 #define ND_DEVICE_MODALIAS_FMT "nd:t%d"