LXR linux/drivers/dax/hmem/device.c

   1// SPDX-License-Identifier: GPL-2.0
   2#include <linux/platform_device.h>
   3#include <linux/memregion.h>
   4#include <linux/module.h>
   5#include <linux/dax.h>
   6#include <linux/mm.h>
   7
   8static bool nohmem;
   9module_param_named(disable, nohmem, bool, 0444);
  10
  11void hmem_register_device(int target_nid, struct resource *r)
  12{
  13        /* define a clean / non-busy resource for the platform device */
  14        struct resource res = {
  15                .start = r->start,
  16                .end = r->end,
  17                .flags = IORESOURCE_MEM,
  18        };
  19        struct platform_device *pdev;
  20        struct memregion_info info;
  21        int rc, id;
  22
  23        if (nohmem)
  24                return;
  25
  26        rc = region_intersects(res.start, resource_size(&res), IORESOURCE_MEM,
  27                        IORES_DESC_SOFT_RESERVED);
  28        if (rc != REGION_INTERSECTS)
  29                return;
  30
  31        id = memregion_alloc(GFP_KERNEL);
  32        if (id < 0) {
  33                pr_err("memregion allocation failure for %pr\n", &res);
  34                return;
  35        }
  36
  37        pdev = platform_device_alloc("hmem", id);
  38        if (!pdev) {
  39                pr_err("hmem device allocation failure for %pr\n", &res);
  40                goto out_pdev;
  41        }
  42
  43        pdev->dev.numa_node = numa_map_to_online_node(target_nid);
  44        info = (struct memregion_info) {
  45                .target_node = target_nid,
  46        };
  47        rc = platform_device_add_data(pdev, &info, sizeof(info));
  48        if (rc < 0) {
  49                pr_err("hmem memregion_info allocation failure for %pr\n", &res);
  50                goto out_pdev;
  51        }
  52
  53        rc = platform_device_add_resources(pdev, &res, 1);
  54        if (rc < 0) {
  55                pr_err("hmem resource allocation failure for %pr\n", &res);
  56                goto out_resource;
  57        }
  58
  59        rc = platform_device_add(pdev);
  60        if (rc < 0) {
  61                dev_err(&pdev->dev, "device add failed for %pr\n", &res);
  62                goto out_resource;
  63        }
  64
  65        return;
  66
  67out_resource:
  68        put_device(&pdev->dev);
  69out_pdev:
  70        memregion_free(id);
  71}
  72
  73static __init int hmem_register_one(struct resource *res, void *data)
  74{
  75        /*
  76         * If the resource is not a top-level resource it was already
  77         * assigned to a device by the HMAT parsing.
  78         */
  79        if (res->parent != &iomem_resource) {
  80                pr_info("HMEM: skip %pr, already claimed\n", res);
  81                return 0;
  82        }
  83
  84        hmem_register_device(phys_to_target_node(res->start), res);
  85
  86        return 0;
  87}
  88
  89static __init int hmem_init(void)
  90{
  91        walk_iomem_res_desc(IORES_DESC_SOFT_RESERVED,
  92                        IORESOURCE_MEM, 0, -1, NULL, hmem_register_one);
  93        return 0;
  94}
  95
  96/*
  97 * As this is a fallback for address ranges unclaimed by the ACPI HMAT
  98 * parsing it must be at an initcall level greater than hmat_init().
  99 */
 100late_initcall(hmem_init);
 101