xref: /openbmc/linux/drivers/nvdimm/e820.c (revision 9cfc5c90)
1 /*
2  * Copyright (c) 2015, Christoph Hellwig.
3  * Copyright (c) 2015, Intel Corporation.
4  */
5 #include <linux/platform_device.h>
6 #include <linux/memory_hotplug.h>
7 #include <linux/libnvdimm.h>
8 #include <linux/module.h>
9 
10 static const struct attribute_group *e820_pmem_attribute_groups[] = {
11 	&nvdimm_bus_attribute_group,
12 	NULL,
13 };
14 
15 static const struct attribute_group *e820_pmem_region_attribute_groups[] = {
16 	&nd_region_attribute_group,
17 	&nd_device_attribute_group,
18 	NULL,
19 };
20 
21 static int e820_pmem_remove(struct platform_device *pdev)
22 {
23 	struct nvdimm_bus *nvdimm_bus = platform_get_drvdata(pdev);
24 
25 	nvdimm_bus_unregister(nvdimm_bus);
26 	return 0;
27 }
28 
29 #ifdef CONFIG_MEMORY_HOTPLUG
30 static int e820_range_to_nid(resource_size_t addr)
31 {
32 	return memory_add_physaddr_to_nid(addr);
33 }
34 #else
35 static int e820_range_to_nid(resource_size_t addr)
36 {
37 	return NUMA_NO_NODE;
38 }
39 #endif
40 
41 static int e820_pmem_probe(struct platform_device *pdev)
42 {
43 	static struct nvdimm_bus_descriptor nd_desc;
44 	struct device *dev = &pdev->dev;
45 	struct nvdimm_bus *nvdimm_bus;
46 	struct resource *p;
47 
48 	nd_desc.attr_groups = e820_pmem_attribute_groups;
49 	nd_desc.provider_name = "e820";
50 	nvdimm_bus = nvdimm_bus_register(dev, &nd_desc);
51 	if (!nvdimm_bus)
52 		goto err;
53 	platform_set_drvdata(pdev, nvdimm_bus);
54 
55 	for (p = iomem_resource.child; p ; p = p->sibling) {
56 		struct nd_region_desc ndr_desc;
57 
58 		if (strncmp(p->name, "Persistent Memory (legacy)", 26) != 0)
59 			continue;
60 
61 		memset(&ndr_desc, 0, sizeof(ndr_desc));
62 		ndr_desc.res = p;
63 		ndr_desc.attr_groups = e820_pmem_region_attribute_groups;
64 		ndr_desc.numa_node = e820_range_to_nid(p->start);
65 		set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);
66 		if (!nvdimm_pmem_region_create(nvdimm_bus, &ndr_desc))
67 			goto err;
68 	}
69 
70 	return 0;
71 
72  err:
73 	nvdimm_bus_unregister(nvdimm_bus);
74 	dev_err(dev, "failed to register legacy persistent memory ranges\n");
75 	return -ENXIO;
76 }
77 
78 static struct platform_driver e820_pmem_driver = {
79 	.probe = e820_pmem_probe,
80 	.remove = e820_pmem_remove,
81 	.driver = {
82 		.name = "e820_pmem",
83 	},
84 };
85 
86 static __init int e820_pmem_init(void)
87 {
88 	return platform_driver_register(&e820_pmem_driver);
89 }
90 
91 static __exit void e820_pmem_exit(void)
92 {
93 	platform_driver_unregister(&e820_pmem_driver);
94 }
95 
96 MODULE_ALIAS("platform:e820_pmem*");
97 MODULE_LICENSE("GPL v2");
98 MODULE_AUTHOR("Intel Corporation");
99 module_init(e820_pmem_init);
100 module_exit(e820_pmem_exit);
101