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 9static bool region_idle; 10module_param_named(region_idle, region_idle, bool, 0644); 11 12static 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 44static struct platform_driver dax_hmem_driver = { 45 .probe = dax_hmem_probe, 46 .driver = { 47 .name = "hmem", 48 }, 49}; 50 51static void release_memregion(void *data) 52{ 53 memregion_free((long) data); 54} 55 56static void release_hmem(void *pdev) 57{ 58 platform_device_unregister(pdev); 59} 60 61static 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 120out_put: 121 platform_device_put(pdev); 122 return rc; 123} 124 125static int dax_hmem_platform_probe(struct platform_device *pdev) 126{ 127 return walk_hmem_resources(&pdev->dev, hmem_register_device); 128} 129 130static struct platform_driver dax_hmem_platform_driver = { 131 .probe = dax_hmem_platform_probe, 132 .driver = { 133 .name = "hmem_platform", 134 }, 135}; 136 137static __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 152static __exit void dax_hmem_exit(void) 153{ 154 platform_driver_unregister(&dax_hmem_driver); 155 platform_driver_unregister(&dax_hmem_platform_driver); 156} 157 158module_init(dax_hmem_init); 159module_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) 164MODULE_SOFTDEP("pre: cxl_acpi"); 165#endif 166#endif 167 168MODULE_ALIAS("platform:hmem*"); 169MODULE_ALIAS("platform:hmem_platform*"); 170MODULE_LICENSE("GPL v2"); 171MODULE_AUTHOR("Intel Corporation"); 172