xref: /openbmc/linux/drivers/nvdimm/e820.c (revision 6d99a79c)
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_register_one(struct resource *res, void *data)
42 {
43 	struct nd_region_desc ndr_desc;
44 	struct nvdimm_bus *nvdimm_bus = data;
45 
46 	memset(&ndr_desc, 0, sizeof(ndr_desc));
47 	ndr_desc.res = res;
48 	ndr_desc.attr_groups = e820_pmem_region_attribute_groups;
49 	ndr_desc.numa_node = e820_range_to_nid(res->start);
50 	set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);
51 	if (!nvdimm_pmem_region_create(nvdimm_bus, &ndr_desc))
52 		return -ENXIO;
53 	return 0;
54 }
55 
56 static int e820_pmem_probe(struct platform_device *pdev)
57 {
58 	static struct nvdimm_bus_descriptor nd_desc;
59 	struct device *dev = &pdev->dev;
60 	struct nvdimm_bus *nvdimm_bus;
61 	int rc = -ENXIO;
62 
63 	nd_desc.attr_groups = e820_pmem_attribute_groups;
64 	nd_desc.provider_name = "e820";
65 	nd_desc.module = THIS_MODULE;
66 	nvdimm_bus = nvdimm_bus_register(dev, &nd_desc);
67 	if (!nvdimm_bus)
68 		goto err;
69 	platform_set_drvdata(pdev, nvdimm_bus);
70 
71 	rc = walk_iomem_res_desc(IORES_DESC_PERSISTENT_MEMORY_LEGACY,
72 			IORESOURCE_MEM, 0, -1, nvdimm_bus, e820_register_one);
73 	if (rc)
74 		goto err;
75 	return 0;
76 err:
77 	nvdimm_bus_unregister(nvdimm_bus);
78 	dev_err(dev, "failed to register legacy persistent memory ranges\n");
79 	return rc;
80 }
81 
82 static struct platform_driver e820_pmem_driver = {
83 	.probe = e820_pmem_probe,
84 	.remove = e820_pmem_remove,
85 	.driver = {
86 		.name = "e820_pmem",
87 	},
88 };
89 
90 module_platform_driver(e820_pmem_driver);
91 
92 MODULE_ALIAS("platform:e820_pmem*");
93 MODULE_LICENSE("GPL v2");
94 MODULE_AUTHOR("Intel Corporation");
95