xref: /openbmc/linux/drivers/nvdimm/e820.c (revision 22d55f02)
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 
11 static const struct attribute_group *e820_pmem_attribute_groups[] = {
12 	&nvdimm_bus_attribute_group,
13 	NULL,
14 };
15 
16 static const struct attribute_group *e820_pmem_region_attribute_groups[] = {
17 	&nd_region_attribute_group,
18 	&nd_device_attribute_group,
19 	NULL,
20 };
21 
22 static int e820_pmem_remove(struct platform_device *pdev)
23 {
24 	struct nvdimm_bus *nvdimm_bus = platform_get_drvdata(pdev);
25 
26 	nvdimm_bus_unregister(nvdimm_bus);
27 	return 0;
28 }
29 
30 #ifdef CONFIG_MEMORY_HOTPLUG
31 static int e820_range_to_nid(resource_size_t addr)
32 {
33 	return memory_add_physaddr_to_nid(addr);
34 }
35 #else
36 static int e820_range_to_nid(resource_size_t addr)
37 {
38 	return NUMA_NO_NODE;
39 }
40 #endif
41 
42 static int e820_register_one(struct resource *res, void *data)
43 {
44 	struct nd_region_desc ndr_desc;
45 	struct nvdimm_bus *nvdimm_bus = data;
46 
47 	memset(&ndr_desc, 0, sizeof(ndr_desc));
48 	ndr_desc.res = res;
49 	ndr_desc.attr_groups = e820_pmem_region_attribute_groups;
50 	ndr_desc.numa_node = e820_range_to_nid(res->start);
51 	ndr_desc.target_node = ndr_desc.numa_node;
52 	set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);
53 	if (!nvdimm_pmem_region_create(nvdimm_bus, &ndr_desc))
54 		return -ENXIO;
55 	return 0;
56 }
57 
58 static int e820_pmem_probe(struct platform_device *pdev)
59 {
60 	static struct nvdimm_bus_descriptor nd_desc;
61 	struct device *dev = &pdev->dev;
62 	struct nvdimm_bus *nvdimm_bus;
63 	int rc = -ENXIO;
64 
65 	nd_desc.attr_groups = e820_pmem_attribute_groups;
66 	nd_desc.provider_name = "e820";
67 	nd_desc.module = THIS_MODULE;
68 	nvdimm_bus = nvdimm_bus_register(dev, &nd_desc);
69 	if (!nvdimm_bus)
70 		goto err;
71 	platform_set_drvdata(pdev, nvdimm_bus);
72 
73 	rc = walk_iomem_res_desc(IORES_DESC_PERSISTENT_MEMORY_LEGACY,
74 			IORESOURCE_MEM, 0, -1, nvdimm_bus, e820_register_one);
75 	if (rc)
76 		goto err;
77 	return 0;
78 err:
79 	nvdimm_bus_unregister(nvdimm_bus);
80 	dev_err(dev, "failed to register legacy persistent memory ranges\n");
81 	return rc;
82 }
83 
84 static struct platform_driver e820_pmem_driver = {
85 	.probe = e820_pmem_probe,
86 	.remove = e820_pmem_remove,
87 	.driver = {
88 		.name = "e820_pmem",
89 	},
90 };
91 
92 module_platform_driver(e820_pmem_driver);
93 
94 MODULE_ALIAS("platform:e820_pmem*");
95 MODULE_LICENSE("GPL v2");
96 MODULE_AUTHOR("Intel Corporation");
97