libnvdimm, nfit: enable support for volatile ranges

Allow volatile nfit ranges to participate in all the same infrastructure
provided for persistent memory regions. A resulting resulting namespace
device will still be called "pmem", but the parent region type will be
"nd_volatile". This is in preparation for disabling the dax ->flush()
operation in the pmem driver when it is hosted on a volatile range.

Cc: Jan Kara <jack@suse.cz>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/nvdimm/nd-core.h b/drivers/nvdimm/nd-core.h
index 4c4bd209e725..86bc19ae30da 100644
--- a/drivers/nvdimm/nd-core.h
+++ b/drivers/nvdimm/nd-core.h
@@ -64,7 +64,16 @@ struct blk_alloc_info {
 
 bool is_nvdimm(struct device *dev);
 bool is_nd_pmem(struct device *dev);
+bool is_nd_volatile(struct device *dev);
 bool is_nd_blk(struct device *dev);
+static inline bool is_nd_region(struct device *dev)
+{
+	return is_nd_pmem(dev) || is_nd_blk(dev) || is_nd_volatile(dev);
+}
+static inline bool is_memory(struct device *dev)
+{
+	return is_nd_pmem(dev) || is_nd_volatile(dev);
+}
 struct nvdimm_bus *walk_to_nvdimm_bus(struct device *nd_dev);
 int __init nvdimm_bus_init(void);
 void nvdimm_bus_exit(void);