libnvdimm, dax: introduce device-dax infrastructure
Device DAX is the device-centric analogue of Filesystem DAX
(CONFIG_FS_DAX). It allows persistent memory ranges to be allocated and
mapped without need of an intervening file system. This initial
infrastructure arranges for a libnvdimm pfn-device to be represented as
a different device-type so that it can be attached to a driver other
than the pmem driver.
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 139bf71..9e1b054 100644
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -306,6 +306,23 @@
}
static DEVICE_ATTR_RO(pfn_seed);
+static ssize_t dax_seed_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct nd_region *nd_region = to_nd_region(dev);
+ ssize_t rc;
+
+ nvdimm_bus_lock(dev);
+ if (nd_region->dax_seed)
+ rc = sprintf(buf, "%s\n", dev_name(nd_region->dax_seed));
+ else
+ rc = sprintf(buf, "\n");
+ nvdimm_bus_unlock(dev);
+
+ return rc;
+}
+static DEVICE_ATTR_RO(dax_seed);
+
static ssize_t read_only_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -335,6 +352,7 @@
&dev_attr_mappings.attr,
&dev_attr_btt_seed.attr,
&dev_attr_pfn_seed.attr,
+ &dev_attr_dax_seed.attr,
&dev_attr_read_only.attr,
&dev_attr_set_cookie.attr,
&dev_attr_available_size.attr,
@@ -353,6 +371,9 @@
if (!is_nd_pmem(dev) && a == &dev_attr_pfn_seed.attr)
return 0;
+ if (!is_nd_pmem(dev) && a == &dev_attr_dax_seed.attr)
+ return 0;
+
if (a != &dev_attr_set_cookie.attr
&& a != &dev_attr_available_size.attr)
return a->mode;
@@ -441,6 +462,13 @@
nd_region_create_pfn_seed(nd_region);
nvdimm_bus_unlock(dev);
}
+ if (is_nd_dax(dev) && probe) {
+ nd_region = to_nd_region(dev->parent);
+ nvdimm_bus_lock(dev);
+ if (nd_region->dax_seed == dev)
+ nd_region_create_dax_seed(nd_region);
+ nvdimm_bus_unlock(dev);
+ }
}
void nd_region_probe_success(struct nvdimm_bus *nvdimm_bus, struct device *dev)
@@ -718,6 +746,7 @@
ida_init(&nd_region->ns_ida);
ida_init(&nd_region->btt_ida);
ida_init(&nd_region->pfn_ida);
+ ida_init(&nd_region->dax_ida);
dev = &nd_region->dev;
dev_set_name(dev, "region%d", nd_region->id);
dev->parent = &nvdimm_bus->dev;