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
dax_hmem_probe(struct platform_device * pdev)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
release_memregion(void * data)51 static void release_memregion(void *data)
52 {
53 memregion_free((long) data);
54 }
55
release_hmem(void * pdev)56 static void release_hmem(void *pdev)
57 {
58 platform_device_unregister(pdev);
59 }
60
hmem_register_device(struct device * host,int target_nid,const struct resource * res)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
dax_hmem_platform_probe(struct platform_device * pdev)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
dax_hmem_init(void)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
dax_hmem_exit(void)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");
172