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/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
index 4bda2e0..b5c5b90 100644
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -47,11 +47,16 @@
.release = nd_region_release,
};
-static bool is_nd_pmem(struct device *dev)
+bool is_nd_pmem(struct device *dev)
{
return dev ? dev->type == &nd_pmem_device_type : false;
}
+bool is_nd_blk(struct device *dev)
+{
+ return dev ? dev->type == &nd_blk_device_type : false;
+}
+
struct nd_region *to_nd_region(struct device *dev)
{
struct nd_region *nd_region = container_of(dev, struct nd_region, dev);
@@ -61,6 +66,37 @@
}
EXPORT_SYMBOL_GPL(to_nd_region);
+/**
+ * nd_region_to_nstype() - region to an integer namespace type
+ * @nd_region: region-device to interrogate
+ *
+ * This is the 'nstype' attribute of a region as well, an input to the
+ * MODALIAS for namespace devices, and bit number for a nvdimm_bus to match
+ * namespace devices with namespace drivers.
+ */
+int nd_region_to_nstype(struct nd_region *nd_region)
+{
+ if (is_nd_pmem(&nd_region->dev)) {
+ u16 i, alias;
+
+ for (i = 0, alias = 0; i < nd_region->ndr_mappings; i++) {
+ struct nd_mapping *nd_mapping = &nd_region->mapping[i];
+ struct nvdimm *nvdimm = nd_mapping->nvdimm;
+
+ if (nvdimm->flags & NDD_ALIASING)
+ alias++;
+ }
+ if (alias)
+ return ND_DEVICE_NAMESPACE_PMEM;
+ else
+ return ND_DEVICE_NAMESPACE_IO;
+ } else if (is_nd_blk(&nd_region->dev)) {
+ return ND_DEVICE_NAMESPACE_BLK;
+ }
+
+ return 0;
+}
+
static ssize_t size_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -88,9 +124,37 @@
}
static DEVICE_ATTR_RO(mappings);
+static ssize_t nstype_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct nd_region *nd_region = to_nd_region(dev);
+
+ return sprintf(buf, "%d\n", nd_region_to_nstype(nd_region));
+}
+static DEVICE_ATTR_RO(nstype);
+
+static ssize_t init_namespaces_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct nd_region_namespaces *num_ns = dev_get_drvdata(dev);
+ ssize_t rc;
+
+ nvdimm_bus_lock(dev);
+ if (num_ns)
+ rc = sprintf(buf, "%d/%d\n", num_ns->active, num_ns->count);
+ else
+ rc = -ENXIO;
+ nvdimm_bus_unlock(dev);
+
+ return rc;
+}
+static DEVICE_ATTR_RO(init_namespaces);
+
static struct attribute *nd_region_attributes[] = {
&dev_attr_size.attr,
+ &dev_attr_nstype.attr,
&dev_attr_mappings.attr,
+ &dev_attr_init_namespaces.attr,
NULL,
};