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                 .memmap_on_memory = false,
  40         };
  41
  42         return PTR_ERR_OR_ZERO(devm_create_dev_dax(&data));
  43 }
  44
  45 static struct platform_driver dax_hmem_driver = {
  46         .probe = dax_hmem_probe,
  47         .driver = {
  48                 .name = "hmem",
  49         },
  50 };
  51
  52 static void release_memregion(void *data)
  53 {
  54         memregion_free((long) data);
  55 }
  56
  57 static void release_hmem(void *pdev)
  58 {
  59         platform_device_unregister(pdev);
  60 }
  61
  62 static int hmem_register_device(struct device *host, int target_nid,
  63                                 const struct resource *res)
  64 {
  65         struct platform_device *pdev;
  66         struct memregion_info info;
  67         long id;
  68         int rc;
  69
  70         if (IS_ENABLED(CONFIG_CXL_REGION) &&
  71             region_intersects(res->start, resource_size(res), IORESOURCE_MEM,
  72                               IORES_DESC_CXL) != REGION_DISJOINT) {
  73                 dev_dbg(host, "deferring range to CXL: %pr\n", res);
  74                 return 0;
  75         }
  76
  77         rc = region_intersects(res->start, resource_size(res), IORESOURCE_MEM,
  78                                IORES_DESC_SOFT_RESERVED);
  79         if (rc != REGION_INTERSECTS)
  80                 return 0;
  81
  82         id = memregion_alloc(GFP_KERNEL);
  83         if (id < 0) {
  84                 dev_err(host, "memregion allocation failure for %pr\n", res);
  85                 return -ENOMEM;
  86         }
  87         rc = devm_add_action_or_reset(host, release_memregion, (void *) id);
  88         if (rc)
  89                 return rc;
  90
  91         pdev = platform_device_alloc("hmem", id);
  92         if (!pdev) {
  93                 dev_err(host, "device allocation failure for %pr\n", res);
  94                 return -ENOMEM;
  95         }
  96
  97         pdev->dev.numa_node = numa_map_to_online_node(target_nid);
  98         info = (struct memregion_info) {
  99                 .target_node = target_nid,
 100                 .range = {
 101                         .start = res->start,
 102                         .end = res->end,
 103                 },
 104         };
 105         rc = platform_device_add_data(pdev, &info, sizeof(info));
 106         if (rc < 0) {
 107                 dev_err(host, "memregion_info allocation failure for %pr\n",
 108                        res);
 109                 goto out_put;
 110         }
 111
 112         rc = platform_device_add(pdev);
 113         if (rc < 0) {
 114                 dev_err(host, "%s add failed for %pr\n", dev_name(&pdev->dev),
 115                         res);
 116                 goto out_put;
 117         }
 118
 119         return devm_add_action_or_reset(host, release_hmem, pdev);
 120
 121 out_put:
 122         platform_device_put(pdev);
 123         return rc;
 124 }
 125
 126 static int dax_hmem_platform_probe(struct platform_device *pdev)
 127 {
 128         return walk_hmem_resources(&pdev->dev, hmem_register_device);
 129 }
 130
 131 static struct platform_driver dax_hmem_platform_driver = {
 132         .probe = dax_hmem_platform_probe,
 133         .driver = {
 134                 .name = "hmem_platform",
 135         },
 136 };
 137
 138 static __init int dax_hmem_init(void)
 139 {
 140         int rc;
 141
 142         rc = platform_driver_register(&dax_hmem_platform_driver);
 143         if (rc)
 144                 return rc;
 145
 146         rc = platform_driver_register(&dax_hmem_driver);
 147         if (rc)
 148                 platform_driver_unregister(&dax_hmem_platform_driver);
 149
 150         return rc;
 151 }
 152
 153 static __exit void dax_hmem_exit(void)
 154 {
 155         platform_driver_unregister(&dax_hmem_driver);
 156         platform_driver_unregister(&dax_hmem_platform_driver);
 157 }
 158
 159 module_init(dax_hmem_init);
 160 module_exit(dax_hmem_exit);
 161
 162 /* Allow for CXL to define its own dax regions */
 163 #if IS_ENABLED(CONFIG_CXL_REGION)
 164 #if IS_MODULE(CONFIG_CXL_ACPI)
 165 MODULE_SOFTDEP("pre: cxl_acpi");
 166 #endif
 167 #endif
 168
 169 MODULE_ALIAS("platform:hmem*");
 170 MODULE_ALIAS("platform:hmem_platform*");
 171 MODULE_LICENSE("GPL v2");
 172 MODULE_AUTHOR("Intel Corporation");