drivers/dax/hmem/hmem.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/pfn_t.h>
   6 #include <linux/dax.h>
   7 #include "../bus.h"
   8
   9 static bool region_idle;
  10 module_param_named(region_idle, region_idle, bool, 0644);
  11
  12 static int dax_hmem_probe(struct platform_device *pdev)
  13 {
  14         unsigned long flags = IORESOURCE_DAX_KMEM;
  15         struct device *dev = &pdev->dev;
  16         struct dax_region *dax_region;
  17         struct memregion_info *mri;
  18         struct dev_dax_data data;
  19
  20         /*
  21          * @region_idle == true indicates that an administrative agent
  22          * wants to manipulate the range partitioning before the devices
  23          * are created, so do not send them to the dax_kmem driver by
  24          * default.
  25          */
  26         if (region_idle)
  27                 flags = 0;
  28
  29         mri = dev->platform_data;
  30         dax_region = alloc_dax_region(dev, pdev->id, &mri->range,
  31                                       mri->target_node, PMD_SIZE, flags);
  32         if (!dax_region)
  33                 return -ENOMEM;
  34
  35         data = (struct dev_dax_data) {
  36                 .dax_region = dax_region,
  37                 .id = -1,
  38                 .size = region_idle ? 0 : range_len(&mri->range),
  39         };
  40
  41         return PTR_ERR_OR_ZERO(devm_create_dev_dax(&data));
  42 }
  43
  44 static struct platform_driver dax_hmem_driver = {
  45         .probe = dax_hmem_probe,
  46         .driver = {
  47                 .name = "hmem",
  48         },
  49 };
  50
  51 static void release_memregion(void *data)
  52 {
  53         memregion_free((long) data);
  54 }
  55
  56 static void release_hmem(void *pdev)
  57 {
  58         platform_device_unregister(pdev);
  59 }
  60
  61 static int hmem_register_device(struct device *host, int target_nid,
  62                                 const struct resource *res)
  63 {
  64         struct platform_device *pdev;
  65         struct memregion_info info;
  66         long id;
  67         int rc;
  68
  69         if (IS_ENABLED(CONFIG_CXL_REGION) &&
  70             region_intersects(res->start, resource_size(res), IORESOURCE_MEM,
  71                               IORES_DESC_CXL) != REGION_DISJOINT) {
  72                 dev_dbg(host, "deferring range to CXL: %pr\n", res);
  73                 return 0;
  74         }
  75
  76         rc = region_intersects(res->start, resource_size(res), IORESOURCE_MEM,
  77                                IORES_DESC_SOFT_RESERVED);
  78         if (rc != REGION_INTERSECTS)
  79                 return 0;
  80
  81         id = memregion_alloc(GFP_KERNEL);
  82         if (id < 0) {
  83                 dev_err(host, "memregion allocation failure for %pr\n", res);
  84                 return -ENOMEM;
  85         }
  86         rc = devm_add_action_or_reset(host, release_memregion, (void *) id);
  87         if (rc)
  88                 return rc;
  89
  90         pdev = platform_device_alloc("hmem", id);
  91         if (!pdev) {
  92                 dev_err(host, "device allocation failure for %pr\n", res);
  93                 return -ENOMEM;
  94         }
  95
  96         pdev->dev.numa_node = numa_map_to_online_node(target_nid);
  97         info = (struct memregion_info) {
  98                 .target_node = target_nid,
  99                 .range = {
 100                         .start = res->start,
 101                         .end = res->end,
 102                 },
 103         };
 104         rc = platform_device_add_data(pdev, &info, sizeof(info));
 105         if (rc < 0) {
 106                 dev_err(host, "memregion_info allocation failure for %pr\n",
 107                        res);
 108                 goto out_put;
 109         }
 110
 111         rc = platform_device_add(pdev);
 112         if (rc < 0) {
 113                 dev_err(host, "%s add failed for %pr\n", dev_name(&pdev->dev),
 114                         res);
 115                 goto out_put;
 116         }
 117
 118         return devm_add_action_or_reset(host, release_hmem, pdev);
 119
 120 out_put:
 121         platform_device_put(pdev);
 122         return rc;
 123 }
 124
 125 static int dax_hmem_platform_probe(struct platform_device *pdev)
 126 {
 127         return walk_hmem_resources(&pdev->dev, hmem_register_device);
 128 }
 129
 130 static struct platform_driver dax_hmem_platform_driver = {
 131         .probe = dax_hmem_platform_probe,
 132         .driver = {
 133                 .name = "hmem_platform",
 134         },
 135 };
 136
 137 static __init int dax_hmem_init(void)
 138 {
 139         int rc;
 140
 141         rc = platform_driver_register(&dax_hmem_platform_driver);
 142         if (rc)
 143                 return rc;
 144
 145         rc = platform_driver_register(&dax_hmem_driver);
 146         if (rc)
 147                 platform_driver_unregister(&dax_hmem_platform_driver);
 148
 149         return rc;
 150 }
 151
 152 static __exit void dax_hmem_exit(void)
 153 {
 154         platform_driver_unregister(&dax_hmem_driver);
 155         platform_driver_unregister(&dax_hmem_platform_driver);
 156 }
 157
 158 module_init(dax_hmem_init);
 159 module_exit(dax_hmem_exit);
 160
 161 /* Allow for CXL to define its own dax regions */
 162 #if IS_ENABLED(CONFIG_CXL_REGION)
 163 #if IS_MODULE(CONFIG_CXL_ACPI)
 164 MODULE_SOFTDEP("pre: cxl_acpi");
 165 #endif
 166 #endif
 167
 168 MODULE_ALIAS("platform:hmem*");
 169 MODULE_ALIAS("platform:hmem_platform*");
 170 MODULE_LICENSE("GPL v2");
 171 MODULE_AUTHOR("Intel Corporation");