libnvdimm: support for legacy (non-aliasing) nvdimms
The libnvdimm region driver is an intermediary driver that translates
non-volatile "region"s into "namespace" sub-devices that are surfaced by
persistent memory block-device drivers (PMEM and BLK).
ACPI 6 introduces the concept that a given nvdimm may simultaneously
offer multiple access modes to its media through direct PMEM load/store
access, or windowed BLK mode. Existing nvdimms mostly implement a PMEM
interface, some offer a BLK-like mode, but never both as ACPI 6 defines.
If an nvdimm is single interfaced, then there is no need for dimm
metadata labels. For these devices we can take the region boundaries
directly to create a child namespace device (nd_namespace_io).
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/uapi/linux/ndctl.h b/include/uapi/linux/ndctl.h
index 3764091..174b637 100644
--- a/include/uapi/linux/ndctl.h
+++ b/include/uapi/linux/ndctl.h
@@ -177,8 +177,18 @@
#define ND_DEVICE_DIMM 1 /* nd_dimm: container for "config data" */
+#define ND_DEVICE_REGION_PMEM 2 /* nd_region: (parent of PMEM namespaces) */
+#define ND_DEVICE_REGION_BLK 3 /* nd_region: (parent of BLK namespaces) */
+#define ND_DEVICE_NAMESPACE_IO 4 /* legacy persistent memory */
+#define ND_DEVICE_NAMESPACE_PMEM 5 /* PMEM namespace (may alias with BLK) */
+#define ND_DEVICE_NAMESPACE_BLK 6 /* BLK namespace (may alias with PMEM) */
enum nd_driver_flags {
ND_DRIVER_DIMM = 1 << ND_DEVICE_DIMM,
+ ND_DRIVER_REGION_PMEM = 1 << ND_DEVICE_REGION_PMEM,
+ ND_DRIVER_REGION_BLK = 1 << ND_DEVICE_REGION_BLK,
+ ND_DRIVER_NAMESPACE_IO = 1 << ND_DEVICE_NAMESPACE_IO,
+ ND_DRIVER_NAMESPACE_PMEM = 1 << ND_DEVICE_NAMESPACE_PMEM,
+ ND_DRIVER_NAMESPACE_BLK = 1 << ND_DEVICE_NAMESPACE_BLK,
};
#endif /* __NDCTL_H__ */