v4.19.13 snapshot.
diff --git a/drivers/nvdimm/e820.c b/drivers/nvdimm/e820.c
new file mode 100644
index 0000000..521eaf5
--- /dev/null
+++ b/drivers/nvdimm/e820.c
@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) 2015, Christoph Hellwig.
+ * Copyright (c) 2015, Intel Corporation.
+ */
+#include <linux/platform_device.h>
+#include <linux/memory_hotplug.h>
+#include <linux/libnvdimm.h>
+#include <linux/module.h>
+
+static const struct attribute_group *e820_pmem_attribute_groups[] = {
+ &nvdimm_bus_attribute_group,
+ NULL,
+};
+
+static const struct attribute_group *e820_pmem_region_attribute_groups[] = {
+ &nd_region_attribute_group,
+ &nd_device_attribute_group,
+ NULL,
+};
+
+static int e820_pmem_remove(struct platform_device *pdev)
+{
+ struct nvdimm_bus *nvdimm_bus = platform_get_drvdata(pdev);
+
+ nvdimm_bus_unregister(nvdimm_bus);
+ return 0;
+}
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+static int e820_range_to_nid(resource_size_t addr)
+{
+ return memory_add_physaddr_to_nid(addr);
+}
+#else
+static int e820_range_to_nid(resource_size_t addr)
+{
+ return NUMA_NO_NODE;
+}
+#endif
+
+static int e820_register_one(struct resource *res, void *data)
+{
+ struct nd_region_desc ndr_desc;
+ struct nvdimm_bus *nvdimm_bus = data;
+
+ memset(&ndr_desc, 0, sizeof(ndr_desc));
+ ndr_desc.res = res;
+ ndr_desc.attr_groups = e820_pmem_region_attribute_groups;
+ ndr_desc.numa_node = e820_range_to_nid(res->start);
+ set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);
+ if (!nvdimm_pmem_region_create(nvdimm_bus, &ndr_desc))
+ return -ENXIO;
+ return 0;
+}
+
+static int e820_pmem_probe(struct platform_device *pdev)
+{
+ static struct nvdimm_bus_descriptor nd_desc;
+ struct device *dev = &pdev->dev;
+ struct nvdimm_bus *nvdimm_bus;
+ int rc = -ENXIO;
+
+ nd_desc.attr_groups = e820_pmem_attribute_groups;
+ nd_desc.provider_name = "e820";
+ nd_desc.module = THIS_MODULE;
+ nvdimm_bus = nvdimm_bus_register(dev, &nd_desc);
+ if (!nvdimm_bus)
+ goto err;
+ platform_set_drvdata(pdev, nvdimm_bus);
+
+ rc = walk_iomem_res_desc(IORES_DESC_PERSISTENT_MEMORY_LEGACY,
+ IORESOURCE_MEM, 0, -1, nvdimm_bus, e820_register_one);
+ if (rc)
+ goto err;
+ return 0;
+err:
+ nvdimm_bus_unregister(nvdimm_bus);
+ dev_err(dev, "failed to register legacy persistent memory ranges\n");
+ return rc;
+}
+
+static struct platform_driver e820_pmem_driver = {
+ .probe = e820_pmem_probe,
+ .remove = e820_pmem_remove,
+ .driver = {
+ .name = "e820_pmem",
+ },
+};
+
+module_platform_driver(e820_pmem_driver);
+
+MODULE_ALIAS("platform:e820_pmem*");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Intel Corporation");