libnvdimm, nfit: dimm/memory-devices

Enable nvdimm devices to be registered on a nvdimm_bus.  The kernel
assigned device id for nvdimm devicesis dynamic.  If userspace needs a
more static identifier it should consult a provider-specific attribute.
In the case where NFIT is the provider, the 'nmemX/nfit/handle' or
'nmemX/nfit/serial' attributes may be used for this purpose.

Cc: Neil Brown <neilb@suse.de>
Cc: <linux-acpi@vger.kernel.org>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Robert Moore <robert.moore@intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 31 insertions, 2 deletions

diff --git a/drivers/nvdimm/core.c b/drivers/nvdimm/core.c
index fa7ab5ad0318..ef957eb37c90 100644
--- a/drivers/nvdimm/core.c
+++ b/drivers/nvdimm/core.c
@@ -18,8 +18,8 @@
 #include <linux/slab.h>
 #include "nd-core.h"
 
-static LIST_HEAD(nvdimm_bus_list);
-static DEFINE_MUTEX(nvdimm_bus_list_mutex);
+LIST_HEAD(nvdimm_bus_list);
+DEFINE_MUTEX(nvdimm_bus_list_mutex);
 static DEFINE_IDA(nd_ida);
 
 static void nvdimm_bus_release(struct device *dev)
@@ -48,6 +48,19 @@ struct nvdimm_bus_descriptor *to_nd_desc(struct nvdimm_bus *nvdimm_bus)
 }
 EXPORT_SYMBOL_GPL(to_nd_desc);
 
+struct nvdimm_bus *walk_to_nvdimm_bus(struct device *nd_dev)
+{
+        struct device *dev;
+
+        for (dev = nd_dev; dev; dev = dev->parent)
+                if (dev->release == nvdimm_bus_release)
+                        break;
+        dev_WARN_ONCE(nd_dev, !dev, "invalid dev, not on nd bus\n");
+        if (dev)
+                return to_nvdimm_bus(dev);
+        return NULL;
+}
+
 static const char *nvdimm_bus_provider(struct nvdimm_bus *nvdimm_bus)
 {
         struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
@@ -121,6 +134,21 @@ struct nvdimm_bus *nvdimm_bus_register(struct device *parent,
 }
 EXPORT_SYMBOL_GPL(nvdimm_bus_register);
 
+static int child_unregister(struct device *dev, void *data)
+{
+        /*
+         * the singular ndctl class device per bus needs to be
+         * "device_destroy"ed, so skip it here
+         *
+         * i.e. remove classless children
+         */
+        if (dev->class)
+                /* pass */;
+        else
+                device_unregister(dev);
+        return 0;
+}
+
 void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus)
 {
         if (!nvdimm_bus)
@@ -130,6 +158,7 @@ void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus)
         list_del_init(&nvdimm_bus->list);
         mutex_unlock(&nvdimm_bus_list_mutex);
 
+        device_for_each_child(&nvdimm_bus->dev, NULL, child_unregister);
         nvdimm_bus_destroy_ndctl(nvdimm_bus);
 
         device_unregister(&nvdimm_bus->dev);