e820.c

 1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * Copyright (c) 2015, Christoph Hellwig.
 4 * Copyright (c) 2015, Intel Corporation.
 5 */
 6#include <linux/platform_device.h>
 7#include <linux/memory_hotplug.h>
 8#include <linux/libnvdimm.h>
 9#include <linux/module.h>
10#include <linux/numa.h>
11
12static void e820_pmem_remove(struct platform_device *pdev)
13{
14	struct nvdimm_bus *nvdimm_bus = platform_get_drvdata(pdev);
15
16	nvdimm_bus_unregister(nvdimm_bus);
17}
18
19static int e820_register_one(struct resource *res, void *data)
20{
21	struct nd_region_desc ndr_desc;
22	struct nvdimm_bus *nvdimm_bus = data;
23	int nid = phys_to_target_node(res->start);
24
25	memset(&ndr_desc, 0, sizeof(ndr_desc));
26	ndr_desc.res = res;
27	ndr_desc.numa_node = numa_map_to_online_node(nid);
28	ndr_desc.target_node = nid;
29	set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);
30	if (!nvdimm_pmem_region_create(nvdimm_bus, &ndr_desc))
31		return -ENXIO;
32	return 0;
33}
34
35static int e820_pmem_probe(struct platform_device *pdev)
36{
37	static struct nvdimm_bus_descriptor nd_desc;
38	struct device *dev = &pdev->dev;
39	struct nvdimm_bus *nvdimm_bus;
40	int rc = -ENXIO;
41
42	nd_desc.provider_name = "e820";
43	nd_desc.module = THIS_MODULE;
44	nvdimm_bus = nvdimm_bus_register(dev, &nd_desc);
45	if (!nvdimm_bus)
46		goto err;
47	platform_set_drvdata(pdev, nvdimm_bus);
48
49	rc = walk_iomem_res_desc(IORES_DESC_PERSISTENT_MEMORY_LEGACY,
50			IORESOURCE_MEM, 0, -1, nvdimm_bus, e820_register_one);
51	if (rc)
52		goto err;
53	return 0;
54err:
55	nvdimm_bus_unregister(nvdimm_bus);
56	dev_err(dev, "failed to register legacy persistent memory ranges\n");
57	return rc;
58}
59
60static struct platform_driver e820_pmem_driver = {
61	.probe = e820_pmem_probe,
62	.remove = e820_pmem_remove,
63	.driver = {
64		.name = "e820_pmem",
65	},
66};
67
68module_platform_driver(e820_pmem_driver);
69
70MODULE_ALIAS("platform:e820_pmem*");
71MODULE_DESCRIPTION("NVDIMM support for e820 type-12 memory");
72MODULE_LICENSE("GPL v2");
73MODULE_AUTHOR("Intel Corporation");