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