xref: /openbmc/linux/drivers/firmware/dmi-id.c (revision bb3982b4)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Export SMBIOS/DMI info via sysfs to userspace
4  *
5  * Copyright 2007, Lennart Poettering
6  */
7 
8 #include <linux/module.h>
9 #include <linux/kernel.h>
10 #include <linux/init.h>
11 #include <linux/dmi.h>
12 #include <linux/device.h>
13 #include <linux/slab.h>
14 
15 struct dmi_device_attribute{
16 	struct device_attribute dev_attr;
17 	int field;
18 };
19 #define to_dmi_dev_attr(_dev_attr) \
20 	container_of(_dev_attr, struct dmi_device_attribute, dev_attr)
21 
22 static ssize_t sys_dmi_field_show(struct device *dev,
23 				  struct device_attribute *attr,
24 				  char *page)
25 {
26 	int field = to_dmi_dev_attr(attr)->field;
27 	ssize_t len;
28 	len = scnprintf(page, PAGE_SIZE, "%s\n", dmi_get_system_info(field));
29 	page[len-1] = '\n';
30 	return len;
31 }
32 
33 #define DMI_ATTR(_name, _mode, _show, _field)			\
34 	{ .dev_attr = __ATTR(_name, _mode, _show, NULL),	\
35 	  .field = _field }
36 
37 #define DEFINE_DMI_ATTR_WITH_SHOW(_name, _mode, _field)		\
38 static struct dmi_device_attribute sys_dmi_##_name##_attr =	\
39 	DMI_ATTR(_name, _mode, sys_dmi_field_show, _field);
40 
41 DEFINE_DMI_ATTR_WITH_SHOW(bios_vendor,		0444, DMI_BIOS_VENDOR);
42 DEFINE_DMI_ATTR_WITH_SHOW(bios_version,		0444, DMI_BIOS_VERSION);
43 DEFINE_DMI_ATTR_WITH_SHOW(bios_date,		0444, DMI_BIOS_DATE);
44 DEFINE_DMI_ATTR_WITH_SHOW(sys_vendor,		0444, DMI_SYS_VENDOR);
45 DEFINE_DMI_ATTR_WITH_SHOW(product_name,		0444, DMI_PRODUCT_NAME);
46 DEFINE_DMI_ATTR_WITH_SHOW(product_version,	0444, DMI_PRODUCT_VERSION);
47 DEFINE_DMI_ATTR_WITH_SHOW(product_serial,	0400, DMI_PRODUCT_SERIAL);
48 DEFINE_DMI_ATTR_WITH_SHOW(product_uuid,		0400, DMI_PRODUCT_UUID);
49 DEFINE_DMI_ATTR_WITH_SHOW(product_sku,		0444, DMI_PRODUCT_SKU);
50 DEFINE_DMI_ATTR_WITH_SHOW(product_family,	0444, DMI_PRODUCT_FAMILY);
51 DEFINE_DMI_ATTR_WITH_SHOW(board_vendor,		0444, DMI_BOARD_VENDOR);
52 DEFINE_DMI_ATTR_WITH_SHOW(board_name,		0444, DMI_BOARD_NAME);
53 DEFINE_DMI_ATTR_WITH_SHOW(board_version,	0444, DMI_BOARD_VERSION);
54 DEFINE_DMI_ATTR_WITH_SHOW(board_serial,		0400, DMI_BOARD_SERIAL);
55 DEFINE_DMI_ATTR_WITH_SHOW(board_asset_tag,	0444, DMI_BOARD_ASSET_TAG);
56 DEFINE_DMI_ATTR_WITH_SHOW(chassis_vendor,	0444, DMI_CHASSIS_VENDOR);
57 DEFINE_DMI_ATTR_WITH_SHOW(chassis_type,		0444, DMI_CHASSIS_TYPE);
58 DEFINE_DMI_ATTR_WITH_SHOW(chassis_version,	0444, DMI_CHASSIS_VERSION);
59 DEFINE_DMI_ATTR_WITH_SHOW(chassis_serial,	0400, DMI_CHASSIS_SERIAL);
60 DEFINE_DMI_ATTR_WITH_SHOW(chassis_asset_tag,	0444, DMI_CHASSIS_ASSET_TAG);
61 
62 static void ascii_filter(char *d, const char *s)
63 {
64 	/* Filter out characters we don't want to see in the modalias string */
65 	for (; *s; s++)
66 		if (*s > ' ' && *s < 127 && *s != ':')
67 			*(d++) = *s;
68 
69 	*d = 0;
70 }
71 
72 static ssize_t get_modalias(char *buffer, size_t buffer_size)
73 {
74 	static const struct mafield {
75 		const char *prefix;
76 		int field;
77 	} fields[] = {
78 		{ "bvn", DMI_BIOS_VENDOR },
79 		{ "bvr", DMI_BIOS_VERSION },
80 		{ "bd",  DMI_BIOS_DATE },
81 		{ "svn", DMI_SYS_VENDOR },
82 		{ "pn",  DMI_PRODUCT_NAME },
83 		{ "pvr", DMI_PRODUCT_VERSION },
84 		{ "rvn", DMI_BOARD_VENDOR },
85 		{ "rn",  DMI_BOARD_NAME },
86 		{ "rvr", DMI_BOARD_VERSION },
87 		{ "cvn", DMI_CHASSIS_VENDOR },
88 		{ "ct",  DMI_CHASSIS_TYPE },
89 		{ "cvr", DMI_CHASSIS_VERSION },
90 		{ NULL,  DMI_NONE }
91 	};
92 
93 	ssize_t l, left;
94 	char *p;
95 	const struct mafield *f;
96 
97 	strcpy(buffer, "dmi");
98 	p = buffer + 3; left = buffer_size - 4;
99 
100 	for (f = fields; f->prefix && left > 0; f++) {
101 		const char *c;
102 		char *t;
103 
104 		c = dmi_get_system_info(f->field);
105 		if (!c)
106 			continue;
107 
108 		t = kmalloc(strlen(c) + 1, GFP_KERNEL);
109 		if (!t)
110 			break;
111 		ascii_filter(t, c);
112 		l = scnprintf(p, left, ":%s%s", f->prefix, t);
113 		kfree(t);
114 
115 		p += l;
116 		left -= l;
117 	}
118 
119 	p[0] = ':';
120 	p[1] = 0;
121 
122 	return p - buffer + 1;
123 }
124 
125 static ssize_t sys_dmi_modalias_show(struct device *dev,
126 				     struct device_attribute *attr, char *page)
127 {
128 	ssize_t r;
129 	r = get_modalias(page, PAGE_SIZE-1);
130 	page[r] = '\n';
131 	page[r+1] = 0;
132 	return r+1;
133 }
134 
135 static struct device_attribute sys_dmi_modalias_attr =
136 	__ATTR(modalias, 0444, sys_dmi_modalias_show, NULL);
137 
138 static struct attribute *sys_dmi_attributes[DMI_STRING_MAX+2];
139 
140 static struct attribute_group sys_dmi_attribute_group = {
141 	.attrs = sys_dmi_attributes,
142 };
143 
144 static const struct attribute_group* sys_dmi_attribute_groups[] = {
145 	&sys_dmi_attribute_group,
146 	NULL
147 };
148 
149 static int dmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
150 {
151 	ssize_t len;
152 
153 	if (add_uevent_var(env, "MODALIAS="))
154 		return -ENOMEM;
155 	len = get_modalias(&env->buf[env->buflen - 1],
156 			   sizeof(env->buf) - env->buflen);
157 	if (len >= (sizeof(env->buf) - env->buflen))
158 		return -ENOMEM;
159 	env->buflen += len;
160 	return 0;
161 }
162 
163 static struct class dmi_class = {
164 	.name = "dmi",
165 	.dev_release = (void(*)(struct device *)) kfree,
166 	.dev_uevent = dmi_dev_uevent,
167 };
168 
169 static struct device *dmi_dev;
170 
171 /* Initialization */
172 
173 #define ADD_DMI_ATTR(_name, _field) \
174 	if (dmi_get_system_info(_field)) \
175 		sys_dmi_attributes[i++] = &sys_dmi_##_name##_attr.dev_attr.attr;
176 
177 /* In a separate function to keep gcc 3.2 happy - do NOT merge this in
178    dmi_id_init! */
179 static void __init dmi_id_init_attr_table(void)
180 {
181 	int i;
182 
183 	/* Not necessarily all DMI fields are available on all
184 	 * systems, hence let's built an attribute table of just
185 	 * what's available */
186 	i = 0;
187 	ADD_DMI_ATTR(bios_vendor,       DMI_BIOS_VENDOR);
188 	ADD_DMI_ATTR(bios_version,      DMI_BIOS_VERSION);
189 	ADD_DMI_ATTR(bios_date,         DMI_BIOS_DATE);
190 	ADD_DMI_ATTR(sys_vendor,        DMI_SYS_VENDOR);
191 	ADD_DMI_ATTR(product_name,      DMI_PRODUCT_NAME);
192 	ADD_DMI_ATTR(product_version,   DMI_PRODUCT_VERSION);
193 	ADD_DMI_ATTR(product_serial,    DMI_PRODUCT_SERIAL);
194 	ADD_DMI_ATTR(product_uuid,      DMI_PRODUCT_UUID);
195 	ADD_DMI_ATTR(product_family,    DMI_PRODUCT_FAMILY);
196 	ADD_DMI_ATTR(product_sku,       DMI_PRODUCT_SKU);
197 	ADD_DMI_ATTR(board_vendor,      DMI_BOARD_VENDOR);
198 	ADD_DMI_ATTR(board_name,        DMI_BOARD_NAME);
199 	ADD_DMI_ATTR(board_version,     DMI_BOARD_VERSION);
200 	ADD_DMI_ATTR(board_serial,      DMI_BOARD_SERIAL);
201 	ADD_DMI_ATTR(board_asset_tag,   DMI_BOARD_ASSET_TAG);
202 	ADD_DMI_ATTR(chassis_vendor,    DMI_CHASSIS_VENDOR);
203 	ADD_DMI_ATTR(chassis_type,      DMI_CHASSIS_TYPE);
204 	ADD_DMI_ATTR(chassis_version,   DMI_CHASSIS_VERSION);
205 	ADD_DMI_ATTR(chassis_serial,    DMI_CHASSIS_SERIAL);
206 	ADD_DMI_ATTR(chassis_asset_tag, DMI_CHASSIS_ASSET_TAG);
207 	sys_dmi_attributes[i++] = &sys_dmi_modalias_attr.attr;
208 }
209 
210 static int __init dmi_id_init(void)
211 {
212 	int ret;
213 
214 	if (!dmi_available)
215 		return -ENODEV;
216 
217 	dmi_id_init_attr_table();
218 
219 	ret = class_register(&dmi_class);
220 	if (ret)
221 		return ret;
222 
223 	dmi_dev = kzalloc(sizeof(*dmi_dev), GFP_KERNEL);
224 	if (!dmi_dev) {
225 		ret = -ENOMEM;
226 		goto fail_class_unregister;
227 	}
228 
229 	dmi_dev->class = &dmi_class;
230 	dev_set_name(dmi_dev, "id");
231 	dmi_dev->groups = sys_dmi_attribute_groups;
232 
233 	ret = device_register(dmi_dev);
234 	if (ret)
235 		goto fail_put_dmi_dev;
236 
237 	return 0;
238 
239 fail_put_dmi_dev:
240 	put_device(dmi_dev);
241 
242 fail_class_unregister:
243 	class_unregister(&dmi_class);
244 
245 	return ret;
246 }
247 
248 arch_initcall(dmi_id_init);
249