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"); 173