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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * coreboot_table.c
4 *
5 * Module providing coreboot table access.
6 *
7 * Copyright 2017 Google Inc.
8 * Copyright 2017 Samuel Holland <samuel@sholland.org>
9 */
10
11#include <linux/acpi.h>
12#include <linux/device.h>
13#include <linux/err.h>
14#include <linux/init.h>
15#include <linux/io.h>
16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/of.h>
19#include <linux/platform_device.h>
20#include <linux/slab.h>
21
22#include "coreboot_table.h"
23
24#define CB_DEV(d) container_of(d, struct coreboot_device, dev)
25#define CB_DRV(d) container_of(d, struct coreboot_driver, drv)
26
27static int coreboot_bus_match(struct device *dev, struct device_driver *drv)
28{
29 struct coreboot_device *device = CB_DEV(dev);
30 struct coreboot_driver *driver = CB_DRV(drv);
31
32 return device->entry.tag == driver->tag;
33}
34
35static int coreboot_bus_probe(struct device *dev)
36{
37 int ret = -ENODEV;
38 struct coreboot_device *device = CB_DEV(dev);
39 struct coreboot_driver *driver = CB_DRV(dev->driver);
40
41 if (driver->probe)
42 ret = driver->probe(device);
43
44 return ret;
45}
46
47static void coreboot_bus_remove(struct device *dev)
48{
49 struct coreboot_device *device = CB_DEV(dev);
50 struct coreboot_driver *driver = CB_DRV(dev->driver);
51
52 if (driver->remove)
53 driver->remove(device);
54}
55
56static struct bus_type coreboot_bus_type = {
57 .name = "coreboot",
58 .match = coreboot_bus_match,
59 .probe = coreboot_bus_probe,
60 .remove = coreboot_bus_remove,
61};
62
63static void coreboot_device_release(struct device *dev)
64{
65 struct coreboot_device *device = CB_DEV(dev);
66
67 kfree(device);
68}
69
70int coreboot_driver_register(struct coreboot_driver *driver)
71{
72 driver->drv.bus = &coreboot_bus_type;
73
74 return driver_register(&driver->drv);
75}
76EXPORT_SYMBOL(coreboot_driver_register);
77
78void coreboot_driver_unregister(struct coreboot_driver *driver)
79{
80 driver_unregister(&driver->drv);
81}
82EXPORT_SYMBOL(coreboot_driver_unregister);
83
84static int coreboot_table_populate(struct device *dev, void *ptr)
85{
86 int i, ret;
87 void *ptr_entry;
88 struct coreboot_device *device;
89 struct coreboot_table_entry *entry;
90 struct coreboot_table_header *header = ptr;
91
92 ptr_entry = ptr + header->header_bytes;
93 for (i = 0; i < header->table_entries; i++) {
94 entry = ptr_entry;
95
96 if (entry->size < sizeof(*entry)) {
97 dev_warn(dev, "coreboot table entry too small!\n");
98 return -EINVAL;
99 }
100
101 device = kzalloc(sizeof(device->dev) + entry->size, GFP_KERNEL);
102 if (!device)
103 return -ENOMEM;
104
105 device->dev.parent = dev;
106 device->dev.bus = &coreboot_bus_type;
107 device->dev.release = coreboot_device_release;
108 memcpy(device->raw, ptr_entry, entry->size);
109
110 switch (device->entry.tag) {
111 case LB_TAG_CBMEM_ENTRY:
112 dev_set_name(&device->dev, "cbmem-%08x",
113 device->cbmem_entry.id);
114 break;
115 default:
116 dev_set_name(&device->dev, "coreboot%d", i);
117 break;
118 }
119
120 ret = device_register(&device->dev);
121 if (ret) {
122 put_device(&device->dev);
123 return ret;
124 }
125
126 ptr_entry += entry->size;
127 }
128
129 return 0;
130}
131
132static int coreboot_table_probe(struct platform_device *pdev)
133{
134 resource_size_t len;
135 struct coreboot_table_header *header;
136 struct resource *res;
137 struct device *dev = &pdev->dev;
138 void *ptr;
139 int ret;
140
141 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
142 if (!res)
143 return -EINVAL;
144
145 len = resource_size(res);
146 if (!res->start || !len)
147 return -EINVAL;
148
149 /* Check just the header first to make sure things are sane */
150 header = memremap(res->start, sizeof(*header), MEMREMAP_WB);
151 if (!header)
152 return -ENOMEM;
153
154 len = header->header_bytes + header->table_bytes;
155 ret = strncmp(header->signature, "LBIO", sizeof(header->signature));
156 memunmap(header);
157 if (ret) {
158 dev_warn(dev, "coreboot table missing or corrupt!\n");
159 return -ENODEV;
160 }
161
162 ptr = memremap(res->start, len, MEMREMAP_WB);
163 if (!ptr)
164 return -ENOMEM;
165
166 ret = coreboot_table_populate(dev, ptr);
167
168 memunmap(ptr);
169
170 return ret;
171}
172
173static int __cb_dev_unregister(struct device *dev, void *dummy)
174{
175 device_unregister(dev);
176 return 0;
177}
178
179static void coreboot_table_remove(struct platform_device *pdev)
180{
181 bus_for_each_dev(&coreboot_bus_type, NULL, NULL, __cb_dev_unregister);
182}
183
184#ifdef CONFIG_ACPI
185static const struct acpi_device_id cros_coreboot_acpi_match[] = {
186 { "GOOGCB00", 0 },
187 { "BOOT0000", 0 },
188 { }
189};
190MODULE_DEVICE_TABLE(acpi, cros_coreboot_acpi_match);
191#endif
192
193#ifdef CONFIG_OF
194static const struct of_device_id coreboot_of_match[] = {
195 { .compatible = "coreboot" },
196 {}
197};
198MODULE_DEVICE_TABLE(of, coreboot_of_match);
199#endif
200
201static struct platform_driver coreboot_table_driver = {
202 .probe = coreboot_table_probe,
203 .remove_new = coreboot_table_remove,
204 .driver = {
205 .name = "coreboot_table",
206 .acpi_match_table = ACPI_PTR(cros_coreboot_acpi_match),
207 .of_match_table = of_match_ptr(coreboot_of_match),
208 },
209};
210
211static int __init coreboot_table_driver_init(void)
212{
213 int ret;
214
215 ret = bus_register(&coreboot_bus_type);
216 if (ret)
217 return ret;
218
219 ret = platform_driver_register(&coreboot_table_driver);
220 if (ret) {
221 bus_unregister(&coreboot_bus_type);
222 return ret;
223 }
224
225 return 0;
226}
227
228static void __exit coreboot_table_driver_exit(void)
229{
230 platform_driver_unregister(&coreboot_table_driver);
231 bus_unregister(&coreboot_bus_type);
232}
233
234module_init(coreboot_table_driver_init);
235module_exit(coreboot_table_driver_exit);
236
237MODULE_AUTHOR("Google, Inc.");
238MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * coreboot_table.c
4 *
5 * Module providing coreboot table access.
6 *
7 * Copyright 2017 Google Inc.
8 * Copyright 2017 Samuel Holland <samuel@sholland.org>
9 */
10
11#include <linux/acpi.h>
12#include <linux/device.h>
13#include <linux/err.h>
14#include <linux/init.h>
15#include <linux/io.h>
16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/of.h>
19#include <linux/platform_device.h>
20#include <linux/slab.h>
21
22#include "coreboot_table.h"
23
24#define CB_DEV(d) container_of(d, struct coreboot_device, dev)
25#define CB_DRV(d) container_of(d, struct coreboot_driver, drv)
26
27static int coreboot_bus_match(struct device *dev, struct device_driver *drv)
28{
29 struct coreboot_device *device = CB_DEV(dev);
30 struct coreboot_driver *driver = CB_DRV(drv);
31 const struct coreboot_device_id *id;
32
33 if (!driver->id_table)
34 return 0;
35
36 for (id = driver->id_table; id->tag; id++) {
37 if (device->entry.tag == id->tag)
38 return 1;
39 }
40
41 return 0;
42}
43
44static int coreboot_bus_probe(struct device *dev)
45{
46 int ret = -ENODEV;
47 struct coreboot_device *device = CB_DEV(dev);
48 struct coreboot_driver *driver = CB_DRV(dev->driver);
49
50 if (driver->probe)
51 ret = driver->probe(device);
52
53 return ret;
54}
55
56static void coreboot_bus_remove(struct device *dev)
57{
58 struct coreboot_device *device = CB_DEV(dev);
59 struct coreboot_driver *driver = CB_DRV(dev->driver);
60
61 if (driver->remove)
62 driver->remove(device);
63}
64
65static int coreboot_bus_uevent(const struct device *dev, struct kobj_uevent_env *env)
66{
67 struct coreboot_device *device = CB_DEV(dev);
68 u32 tag = device->entry.tag;
69
70 return add_uevent_var(env, "MODALIAS=coreboot:t%08X", tag);
71}
72
73static const struct bus_type coreboot_bus_type = {
74 .name = "coreboot",
75 .match = coreboot_bus_match,
76 .probe = coreboot_bus_probe,
77 .remove = coreboot_bus_remove,
78 .uevent = coreboot_bus_uevent,
79};
80
81static void coreboot_device_release(struct device *dev)
82{
83 struct coreboot_device *device = CB_DEV(dev);
84
85 kfree(device);
86}
87
88int coreboot_driver_register(struct coreboot_driver *driver)
89{
90 driver->drv.bus = &coreboot_bus_type;
91
92 return driver_register(&driver->drv);
93}
94EXPORT_SYMBOL(coreboot_driver_register);
95
96void coreboot_driver_unregister(struct coreboot_driver *driver)
97{
98 driver_unregister(&driver->drv);
99}
100EXPORT_SYMBOL(coreboot_driver_unregister);
101
102static int coreboot_table_populate(struct device *dev, void *ptr)
103{
104 int i, ret;
105 void *ptr_entry;
106 struct coreboot_device *device;
107 struct coreboot_table_entry *entry;
108 struct coreboot_table_header *header = ptr;
109
110 ptr_entry = ptr + header->header_bytes;
111 for (i = 0; i < header->table_entries; i++) {
112 entry = ptr_entry;
113
114 if (entry->size < sizeof(*entry)) {
115 dev_warn(dev, "coreboot table entry too small!\n");
116 return -EINVAL;
117 }
118
119 device = kzalloc(sizeof(device->dev) + entry->size, GFP_KERNEL);
120 if (!device)
121 return -ENOMEM;
122
123 device->dev.parent = dev;
124 device->dev.bus = &coreboot_bus_type;
125 device->dev.release = coreboot_device_release;
126 memcpy(device->raw, ptr_entry, entry->size);
127
128 switch (device->entry.tag) {
129 case LB_TAG_CBMEM_ENTRY:
130 dev_set_name(&device->dev, "cbmem-%08x",
131 device->cbmem_entry.id);
132 break;
133 default:
134 dev_set_name(&device->dev, "coreboot%d", i);
135 break;
136 }
137
138 ret = device_register(&device->dev);
139 if (ret) {
140 put_device(&device->dev);
141 return ret;
142 }
143
144 ptr_entry += entry->size;
145 }
146
147 return 0;
148}
149
150static int coreboot_table_probe(struct platform_device *pdev)
151{
152 resource_size_t len;
153 struct coreboot_table_header *header;
154 struct resource *res;
155 struct device *dev = &pdev->dev;
156 void *ptr;
157 int ret;
158
159 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
160 if (!res)
161 return -EINVAL;
162
163 len = resource_size(res);
164 if (!res->start || !len)
165 return -EINVAL;
166
167 /* Check just the header first to make sure things are sane */
168 header = memremap(res->start, sizeof(*header), MEMREMAP_WB);
169 if (!header)
170 return -ENOMEM;
171
172 len = header->header_bytes + header->table_bytes;
173 ret = strncmp(header->signature, "LBIO", sizeof(header->signature));
174 memunmap(header);
175 if (ret) {
176 dev_warn(dev, "coreboot table missing or corrupt!\n");
177 return -ENODEV;
178 }
179
180 ptr = memremap(res->start, len, MEMREMAP_WB);
181 if (!ptr)
182 return -ENOMEM;
183
184 ret = coreboot_table_populate(dev, ptr);
185
186 memunmap(ptr);
187
188 return ret;
189}
190
191static int __cb_dev_unregister(struct device *dev, void *dummy)
192{
193 device_unregister(dev);
194 return 0;
195}
196
197static void coreboot_table_remove(struct platform_device *pdev)
198{
199 bus_for_each_dev(&coreboot_bus_type, NULL, NULL, __cb_dev_unregister);
200}
201
202#ifdef CONFIG_ACPI
203static const struct acpi_device_id cros_coreboot_acpi_match[] = {
204 { "GOOGCB00", 0 },
205 { "BOOT0000", 0 },
206 { }
207};
208MODULE_DEVICE_TABLE(acpi, cros_coreboot_acpi_match);
209#endif
210
211#ifdef CONFIG_OF
212static const struct of_device_id coreboot_of_match[] = {
213 { .compatible = "coreboot" },
214 {}
215};
216MODULE_DEVICE_TABLE(of, coreboot_of_match);
217#endif
218
219static struct platform_driver coreboot_table_driver = {
220 .probe = coreboot_table_probe,
221 .remove_new = coreboot_table_remove,
222 .driver = {
223 .name = "coreboot_table",
224 .acpi_match_table = ACPI_PTR(cros_coreboot_acpi_match),
225 .of_match_table = of_match_ptr(coreboot_of_match),
226 },
227};
228
229static int __init coreboot_table_driver_init(void)
230{
231 int ret;
232
233 ret = bus_register(&coreboot_bus_type);
234 if (ret)
235 return ret;
236
237 ret = platform_driver_register(&coreboot_table_driver);
238 if (ret) {
239 bus_unregister(&coreboot_bus_type);
240 return ret;
241 }
242
243 return 0;
244}
245
246static void __exit coreboot_table_driver_exit(void)
247{
248 platform_driver_unregister(&coreboot_table_driver);
249 bus_unregister(&coreboot_bus_type);
250}
251
252module_init(coreboot_table_driver_init);
253module_exit(coreboot_table_driver_exit);
254
255MODULE_AUTHOR("Google, Inc.");
256MODULE_LICENSE("GPL");