libnvdimm, label: add address abstraction identifiers

Starting with v1.2 labels, 'address abstractions' can be hinted via an
address abstraction id that implies an info-block format. The standard
address abstraction in the specification is the v2 format of the
Block-Translation-Table (BTT). Support for that is saved for a later
patch, for now we add support for the Linux supported address
abstractions BTT (v1), PFN, and DAX.

The new 'holder_class' attribute for namespace devices is added for
tooling to specify the 'abstraction_guid' to store in the namespace label.
For v1.1 labels this field is undefined and any setting of
'holder_class' away from the default 'none' value will only have effect
until the driver is unloaded. Setting 'holder_class' requires that
whatever device tries to claim the namespace must be of the specified
class.

Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 28 insertions, 0 deletions

diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c
index 7ceb5fa4f2a1..de9b1cce242e 100644
--- a/drivers/nvdimm/claim.c
+++ b/drivers/nvdimm/claim.c
@@ -184,6 +184,34 @@ ssize_t nd_namespace_store(struct device *dev,
 	}
 
 	ndns = to_ndns(found);
+
+	switch (ndns->claim_class) {
+	case NVDIMM_CCLASS_NONE:
+		break;
+	case NVDIMM_CCLASS_BTT:
+		if (!is_nd_btt(dev)) {
+			len = -EBUSY;
+			goto out_attach;
+		}
+		break;
+	case NVDIMM_CCLASS_PFN:
+		if (!is_nd_pfn(dev)) {
+			len = -EBUSY;
+			goto out_attach;
+		}
+		break;
+	case NVDIMM_CCLASS_DAX:
+		if (!is_nd_dax(dev)) {
+			len = -EBUSY;
+			goto out_attach;
+		}
+		break;
+	default:
+		len = -EBUSY;
+		goto out_attach;
+		break;
+	}
+
 	if (__nvdimm_namespace_capacity(ndns) < SZ_16M) {
 		dev_dbg(dev, "%s too small to host\n", name);
 		len = -ENXIO;