This source file includes following definitions.
- get_first_smbios_priv
- run_smbios_call
- dell_smbios_wmi_call
- dell_smbios_wmi_filter
- dell_smbios_wmi_probe
- dell_smbios_wmi_remove
- parse_b1_table
- find_b1
- init_dell_smbios_wmi
- exit_dell_smbios_wmi
1
2
3
4
5
6
7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
8
9 #include <linux/dmi.h>
10 #include <linux/list.h>
11 #include <linux/module.h>
12 #include <linux/mutex.h>
13 #include <linux/uaccess.h>
14 #include <linux/wmi.h>
15 #include "dell-smbios.h"
16 #include "dell-wmi-descriptor.h"
17
18 static DEFINE_MUTEX(call_mutex);
19 static DEFINE_MUTEX(list_mutex);
20 static int wmi_supported;
21
22 struct misc_bios_flags_structure {
23 struct dmi_header header;
24 u16 flags0;
25 } __packed;
26 #define FLAG_HAS_ACPI_WMI 0x02
27
28 #define DELL_WMI_SMBIOS_GUID "A80593CE-A997-11DA-B012-B622A1EF5492"
29
30 struct wmi_smbios_priv {
31 struct dell_wmi_smbios_buffer *buf;
32 struct list_head list;
33 struct wmi_device *wdev;
34 struct device *child;
35 u32 req_buf_size;
36 };
37 static LIST_HEAD(wmi_list);
38
39 static inline struct wmi_smbios_priv *get_first_smbios_priv(void)
40 {
41 return list_first_entry_or_null(&wmi_list,
42 struct wmi_smbios_priv,
43 list);
44 }
45
46 static int run_smbios_call(struct wmi_device *wdev)
47 {
48 struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
49 struct wmi_smbios_priv *priv;
50 struct acpi_buffer input;
51 union acpi_object *obj;
52 acpi_status status;
53
54 priv = dev_get_drvdata(&wdev->dev);
55 input.length = priv->req_buf_size - sizeof(u64);
56 input.pointer = &priv->buf->std;
57
58 dev_dbg(&wdev->dev, "evaluating: %u/%u [%x,%x,%x,%x]\n",
59 priv->buf->std.cmd_class, priv->buf->std.cmd_select,
60 priv->buf->std.input[0], priv->buf->std.input[1],
61 priv->buf->std.input[2], priv->buf->std.input[3]);
62
63 status = wmidev_evaluate_method(wdev, 0, 1, &input, &output);
64 if (ACPI_FAILURE(status))
65 return -EIO;
66 obj = (union acpi_object *)output.pointer;
67 if (obj->type != ACPI_TYPE_BUFFER) {
68 dev_dbg(&wdev->dev, "received type: %d\n", obj->type);
69 if (obj->type == ACPI_TYPE_INTEGER)
70 dev_dbg(&wdev->dev, "SMBIOS call failed: %llu\n",
71 obj->integer.value);
72 return -EIO;
73 }
74 memcpy(&priv->buf->std, obj->buffer.pointer, obj->buffer.length);
75 dev_dbg(&wdev->dev, "result: [%08x,%08x,%08x,%08x]\n",
76 priv->buf->std.output[0], priv->buf->std.output[1],
77 priv->buf->std.output[2], priv->buf->std.output[3]);
78 kfree(output.pointer);
79
80 return 0;
81 }
82
83 static int dell_smbios_wmi_call(struct calling_interface_buffer *buffer)
84 {
85 struct wmi_smbios_priv *priv;
86 size_t difference;
87 size_t size;
88 int ret;
89
90 mutex_lock(&call_mutex);
91 priv = get_first_smbios_priv();
92 if (!priv) {
93 ret = -ENODEV;
94 goto out_wmi_call;
95 }
96
97 size = sizeof(struct calling_interface_buffer);
98 difference = priv->req_buf_size - sizeof(u64) - size;
99
100 memset(&priv->buf->ext, 0, difference);
101 memcpy(&priv->buf->std, buffer, size);
102 ret = run_smbios_call(priv->wdev);
103 memcpy(buffer, &priv->buf->std, size);
104 out_wmi_call:
105 mutex_unlock(&call_mutex);
106
107 return ret;
108 }
109
110 static long dell_smbios_wmi_filter(struct wmi_device *wdev, unsigned int cmd,
111 struct wmi_ioctl_buffer *arg)
112 {
113 struct wmi_smbios_priv *priv;
114 int ret = 0;
115
116 switch (cmd) {
117 case DELL_WMI_SMBIOS_CMD:
118 mutex_lock(&call_mutex);
119 priv = dev_get_drvdata(&wdev->dev);
120 if (!priv) {
121 ret = -ENODEV;
122 goto fail_smbios_cmd;
123 }
124 memcpy(priv->buf, arg, priv->req_buf_size);
125 if (dell_smbios_call_filter(&wdev->dev, &priv->buf->std)) {
126 dev_err(&wdev->dev, "Invalid call %d/%d:%8x\n",
127 priv->buf->std.cmd_class,
128 priv->buf->std.cmd_select,
129 priv->buf->std.input[0]);
130 ret = -EFAULT;
131 goto fail_smbios_cmd;
132 }
133 ret = run_smbios_call(priv->wdev);
134 if (ret)
135 goto fail_smbios_cmd;
136 memcpy(arg, priv->buf, priv->req_buf_size);
137 fail_smbios_cmd:
138 mutex_unlock(&call_mutex);
139 break;
140 default:
141 ret = -ENOIOCTLCMD;
142 }
143 return ret;
144 }
145
146 static int dell_smbios_wmi_probe(struct wmi_device *wdev, const void *context)
147 {
148 struct wmi_driver *wdriver =
149 container_of(wdev->dev.driver, struct wmi_driver, driver);
150 struct wmi_smbios_priv *priv;
151 u32 hotfix;
152 int count;
153 int ret;
154
155 ret = dell_wmi_get_descriptor_valid();
156 if (ret)
157 return ret;
158
159 priv = devm_kzalloc(&wdev->dev, sizeof(struct wmi_smbios_priv),
160 GFP_KERNEL);
161 if (!priv)
162 return -ENOMEM;
163
164
165 if (!dell_wmi_get_size(&priv->req_buf_size))
166 return -EPROBE_DEFER;
167
168
169 if (!dell_wmi_get_hotfix(&hotfix))
170 return -EPROBE_DEFER;
171 if (!hotfix) {
172 dev_warn(&wdev->dev,
173 "WMI SMBIOS userspace interface not supported(%u), try upgrading to a newer BIOS\n",
174 hotfix);
175 wdriver->filter_callback = NULL;
176 }
177
178
179 priv->req_buf_size += sizeof(u64);
180 ret = set_required_buffer_size(wdev, priv->req_buf_size);
181 if (ret)
182 return ret;
183
184 count = get_order(priv->req_buf_size);
185 priv->buf = (void *)__get_free_pages(GFP_KERNEL, count);
186 if (!priv->buf)
187 return -ENOMEM;
188
189
190 wdev->dev.id = 1;
191 ret = dell_smbios_register_device(&wdev->dev, &dell_smbios_wmi_call);
192 if (ret)
193 goto fail_register;
194
195 priv->wdev = wdev;
196 dev_set_drvdata(&wdev->dev, priv);
197 mutex_lock(&list_mutex);
198 list_add_tail(&priv->list, &wmi_list);
199 mutex_unlock(&list_mutex);
200
201 return 0;
202
203 fail_register:
204 free_pages((unsigned long)priv->buf, count);
205 return ret;
206 }
207
208 static int dell_smbios_wmi_remove(struct wmi_device *wdev)
209 {
210 struct wmi_smbios_priv *priv = dev_get_drvdata(&wdev->dev);
211 int count;
212
213 mutex_lock(&call_mutex);
214 mutex_lock(&list_mutex);
215 list_del(&priv->list);
216 mutex_unlock(&list_mutex);
217 dell_smbios_unregister_device(&wdev->dev);
218 count = get_order(priv->req_buf_size);
219 free_pages((unsigned long)priv->buf, count);
220 mutex_unlock(&call_mutex);
221 return 0;
222 }
223
224 static const struct wmi_device_id dell_smbios_wmi_id_table[] = {
225 { .guid_string = DELL_WMI_SMBIOS_GUID },
226 { },
227 };
228
229 static void parse_b1_table(const struct dmi_header *dm)
230 {
231 struct misc_bios_flags_structure *flags =
232 container_of(dm, struct misc_bios_flags_structure, header);
233
234
235 if (dm->length < 12)
236 return;
237 if (dm->handle != 0xb100)
238 return;
239 if ((flags->flags0 & FLAG_HAS_ACPI_WMI))
240 wmi_supported = 1;
241 }
242
243 static void find_b1(const struct dmi_header *dm, void *dummy)
244 {
245 switch (dm->type) {
246 case 0xb1:
247 parse_b1_table(dm);
248 break;
249 }
250 }
251
252 static struct wmi_driver dell_smbios_wmi_driver = {
253 .driver = {
254 .name = "dell-smbios",
255 },
256 .probe = dell_smbios_wmi_probe,
257 .remove = dell_smbios_wmi_remove,
258 .id_table = dell_smbios_wmi_id_table,
259 .filter_callback = dell_smbios_wmi_filter,
260 };
261
262 int init_dell_smbios_wmi(void)
263 {
264 dmi_walk(find_b1, NULL);
265
266 if (!wmi_supported)
267 return -ENODEV;
268
269 return wmi_driver_register(&dell_smbios_wmi_driver);
270 }
271
272 void exit_dell_smbios_wmi(void)
273 {
274 wmi_driver_unregister(&dell_smbios_wmi_driver);
275 }
276
277 MODULE_DEVICE_TABLE(wmi, dell_smbios_wmi_id_table);