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1// SPDX-License-Identifier: GPL-2.02#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 agent22 * wants to manipulate the range partitioning before the devices23 * are created, so do not send them to the dax_kmem driver by24 * 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 45static struct platform_driver dax_hmem_driver = {46 .probe = dax_hmem_probe,47 .driver = {48 .name = "hmem",49 },50};51 52static void release_memregion(void *data)53{54 memregion_free((long) data);55}56 57static void release_hmem(void *pdev)58{59 platform_device_unregister(pdev);60}61 62static 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 121out_put:122 platform_device_put(pdev);123 return rc;124}125 126static int dax_hmem_platform_probe(struct platform_device *pdev)127{128 return walk_hmem_resources(&pdev->dev, hmem_register_device);129}130 131static struct platform_driver dax_hmem_platform_driver = {132 .probe = dax_hmem_platform_probe,133 .driver = {134 .name = "hmem_platform",135 },136};137 138static __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 153static __exit void dax_hmem_exit(void)154{155 platform_driver_unregister(&dax_hmem_driver);156 platform_driver_unregister(&dax_hmem_platform_driver);157}158 159module_init(dax_hmem_init);160module_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)165MODULE_SOFTDEP("pre: cxl_acpi");166#endif167#endif168 169MODULE_ALIAS("platform:hmem*");170MODULE_ALIAS("platform:hmem_platform*");171MODULE_DESCRIPTION("HMEM DAX: direct access to 'specific purpose' memory");172MODULE_LICENSE("GPL v2");173MODULE_AUTHOR("Intel Corporation");174