arch/x86/kernel/pmem.c

   1 /*
   2  * Copyright (c) 2015, Christoph Hellwig.
   3  * Copyright (c) 2015, Intel Corporation.
   4  */
   5 #include <linux/platform_device.h>
   6 #include <linux/libnvdimm.h>
   7 #include <linux/module.h>
   8 #include <asm/e820.h>
   9
  10 static void e820_pmem_release(struct device *dev)
  11 {
  12         struct nvdimm_bus *nvdimm_bus = dev->platform_data;
  13
  14         if (nvdimm_bus)
  15                 nvdimm_bus_unregister(nvdimm_bus);
  16 }
  17
  18 static struct platform_device e820_pmem = {
  19         .name = "e820_pmem",
  20         .id = -1,
  21         .dev = {
  22                 .release = e820_pmem_release,
  23         },
  24 };
  25
  26 static const struct attribute_group *e820_pmem_attribute_groups[] = {
  27         &nvdimm_bus_attribute_group,
  28         NULL,
  29 };
  30
  31 static const struct attribute_group *e820_pmem_region_attribute_groups[] = {
  32         &nd_region_attribute_group,
  33         &nd_device_attribute_group,
  34         NULL,
  35 };
  36
  37 static __init int register_e820_pmem(void)
  38 {
  39         static struct nvdimm_bus_descriptor nd_desc;
  40         struct device *dev = &e820_pmem.dev;
  41         struct nvdimm_bus *nvdimm_bus;
  42         int rc, i;
  43
  44         rc = platform_device_register(&e820_pmem);
  45         if (rc)
  46                 return rc;
  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         dev->platform_data = nvdimm_bus;
  54
  55         for (i = 0; i < e820.nr_map; i++) {
  56                 struct e820entry *ei = &e820.map[i];
  57                 struct resource res = {
  58                         .flags  = IORESOURCE_MEM,
  59                         .start  = ei->addr,
  60                         .end    = ei->addr + ei->size - 1,
  61                 };
  62                 struct nd_region_desc ndr_desc;
  63
  64                 if (ei->type != E820_PRAM)
  65                         continue;
  66
  67                 memset(&ndr_desc, 0, sizeof(ndr_desc));
  68                 ndr_desc.res = &res;
  69                 ndr_desc.attr_groups = e820_pmem_region_attribute_groups;
  70                 ndr_desc.numa_node = NUMA_NO_NODE;
  71                 if (!nvdimm_pmem_region_create(nvdimm_bus, &ndr_desc))
  72                         goto err;
  73         }
  74
  75         return 0;
  76
  77  err:
  78         dev_err(dev, "failed to register legacy persistent memory ranges\n");
  79         platform_device_unregister(&e820_pmem);
  80         return -ENXIO;
  81 }
  82 device_initcall(register_e820_pmem);