tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 struct dev_dax *dev_dax;
20
21 /*
22 * @region_idle == true indicates that an administrative agent
23 * wants to manipulate the range partitioning before the devices
24 * are created, so do not send them to the dax_kmem driver by
25 * default.
26 */
27 if (region_idle)
28 flags = 0;
29
30 mri = dev->platform_data;
31 dax_region = alloc_dax_region(dev, pdev->id, &mri->range,
32 mri->target_node, PMD_SIZE, flags);
33 if (!dax_region)
34 return -ENOMEM;
35
36 data = (struct dev_dax_data) {
37 .dax_region = dax_region,
38 .id = -1,
39 .size = region_idle ? 0 : range_len(&mri->range),
40 };
41 dev_dax = devm_create_dev_dax(&data);
42 if (IS_ERR(dev_dax))
43 return PTR_ERR(dev_dax);
44
45 /* child dev_dax instances now own the lifetime of the dax_region */
46 dax_region_put(dax_region);
47 return 0;
48}
49
50static struct platform_driver dax_hmem_driver = {
51 .probe = dax_hmem_probe,
52 .driver = {
53 .name = "hmem",
54 },
55};
56
57static void release_memregion(void *data)
58{
59 memregion_free((long) data);
60}
61
62static void release_hmem(void *pdev)
63{
64 platform_device_unregister(pdev);
65}
66
67static int hmem_register_device(struct device *host, int target_nid,
68 const struct resource *res)
69{
70 struct platform_device *pdev;
71 struct memregion_info info;
72 long id;
73 int rc;
74
75 if (IS_ENABLED(CONFIG_CXL_REGION) &&
76 region_intersects(res->start, resource_size(res), IORESOURCE_MEM,
77 IORES_DESC_CXL) != REGION_DISJOINT) {
78 dev_dbg(host, "deferring range to CXL: %pr\n", res);
79 return 0;
80 }
81
82 rc = region_intersects(res->start, resource_size(res), IORESOURCE_MEM,
83 IORES_DESC_SOFT_RESERVED);
84 if (rc != REGION_INTERSECTS)
85 return 0;
86
87 id = memregion_alloc(GFP_KERNEL);
88 if (id < 0) {
89 dev_err(host, "memregion allocation failure for %pr\n", res);
90 return -ENOMEM;
91 }
92 rc = devm_add_action_or_reset(host, release_memregion, (void *) id);
93 if (rc)
94 return rc;
95
96 pdev = platform_device_alloc("hmem", id);
97 if (!pdev) {
98 dev_err(host, "device allocation failure for %pr\n", res);
99 return -ENOMEM;
100 }
101
102 pdev->dev.numa_node = numa_map_to_online_node(target_nid);
103 info = (struct memregion_info) {
104 .target_node = target_nid,
105 .range = {
106 .start = res->start,
107 .end = res->end,
108 },
109 };
110 rc = platform_device_add_data(pdev, &info, sizeof(info));
111 if (rc < 0) {
112 dev_err(host, "memregion_info allocation failure for %pr\n",
113 res);
114 goto out_put;
115 }
116
117 rc = platform_device_add(pdev);
118 if (rc < 0) {
119 dev_err(host, "%s add failed for %pr\n", dev_name(&pdev->dev),
120 res);
121 goto out_put;
122 }
123
124 return devm_add_action_or_reset(host, release_hmem, pdev);
125
126out_put:
127 platform_device_put(pdev);
128 return rc;
129}
130
131static int dax_hmem_platform_probe(struct platform_device *pdev)
132{
133 return walk_hmem_resources(&pdev->dev, hmem_register_device);
134}
135
136static struct platform_driver dax_hmem_platform_driver = {
137 .probe = dax_hmem_platform_probe,
138 .driver = {
139 .name = "hmem_platform",
140 },
141};
142
143static __init int dax_hmem_init(void)
144{
145 int rc;
146
147 rc = platform_driver_register(&dax_hmem_platform_driver);
148 if (rc)
149 return rc;
150
151 rc = platform_driver_register(&dax_hmem_driver);
152 if (rc)
153 platform_driver_unregister(&dax_hmem_platform_driver);
154
155 return rc;
156}
157
158static __exit void dax_hmem_exit(void)
159{
160 platform_driver_unregister(&dax_hmem_driver);
161 platform_driver_unregister(&dax_hmem_platform_driver);
162}
163
164module_init(dax_hmem_init);
165module_exit(dax_hmem_exit);
166
167/* Allow for CXL to define its own dax regions */
168#if IS_ENABLED(CONFIG_CXL_REGION)
169#if IS_MODULE(CONFIG_CXL_ACPI)
170MODULE_SOFTDEP("pre: cxl_acpi");
171#endif
172#endif
173
174MODULE_ALIAS("platform:hmem*");
175MODULE_ALIAS("platform:hmem_platform*");
176MODULE_LICENSE("GPL v2");
177MODULE_AUTHOR("Intel Corporation");