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/bus.c b/drivers/nvdimm/bus.c
index a0308f1..4b77665 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -13,6 +13,7 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/vmalloc.h>
#include <linux/uaccess.h>
+#include <linux/module.h>
#include <linux/fcntl.h>
#include <linux/async.h>
#include <linux/ndctl.h>
@@ -33,6 +34,12 @@
{
if (is_nvdimm(dev))
return ND_DEVICE_DIMM;
+ else if (is_nd_pmem(dev))
+ return ND_DEVICE_REGION_PMEM;
+ else if (is_nd_blk(dev))
+ return ND_DEVICE_REGION_BLK;
+ else if (is_nd_pmem(dev->parent) || is_nd_blk(dev->parent))
+ return nd_region_to_nstype(to_nd_region(dev->parent));
return 0;
}
@@ -50,27 +57,46 @@
return test_bit(to_nd_device_type(dev), &nd_drv->type);
}
+static struct module *to_bus_provider(struct device *dev)
+{
+ /* pin bus providers while regions are enabled */
+ if (is_nd_pmem(dev) || is_nd_blk(dev)) {
+ struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
+
+ return nvdimm_bus->module;
+ }
+ return NULL;
+}
+
static int nvdimm_bus_probe(struct device *dev)
{
struct nd_device_driver *nd_drv = to_nd_device_driver(dev->driver);
+ struct module *provider = to_bus_provider(dev);
struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
int rc;
+ if (!try_module_get(provider))
+ return -ENXIO;
+
rc = nd_drv->probe(dev);
dev_dbg(&nvdimm_bus->dev, "%s.probe(%s) = %d\n", dev->driver->name,
dev_name(dev), rc);
+ if (rc != 0)
+ module_put(provider);
return rc;
}
static int nvdimm_bus_remove(struct device *dev)
{
struct nd_device_driver *nd_drv = to_nd_device_driver(dev->driver);
+ struct module *provider = to_bus_provider(dev);
struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
int rc;
rc = nd_drv->remove(dev);
dev_dbg(&nvdimm_bus->dev, "%s.remove(%s) = %d\n", dev->driver->name,
dev_name(dev), rc);
+ module_put(provider);
return rc;
}