1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
|
/*
* WMI methods for use with dell-smbios
*
* Copyright (c) 2017 Dell Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/dmi.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/uaccess.h>
#include <linux/wmi.h>
#include "dell-smbios.h"
#include "dell-wmi-descriptor.h"
static DEFINE_MUTEX(call_mutex);
static DEFINE_MUTEX(list_mutex);
static int wmi_supported;
struct misc_bios_flags_structure {
struct dmi_header header;
u16 flags0;
} __packed;
#define FLAG_HAS_ACPI_WMI 0x02
#define DELL_WMI_SMBIOS_GUID "A80593CE-A997-11DA-B012-B622A1EF5492"
struct wmi_smbios_priv {
struct dell_wmi_smbios_buffer *buf;
struct list_head list;
struct wmi_device *wdev;
struct device *child;
u32 req_buf_size;
};
static LIST_HEAD(wmi_list);
static inline struct wmi_smbios_priv *get_first_smbios_priv(void)
{
return list_first_entry_or_null(&wmi_list,
struct wmi_smbios_priv,
list);
}
static int run_smbios_call(struct wmi_device *wdev)
{
struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
struct wmi_smbios_priv *priv;
struct acpi_buffer input;
union acpi_object *obj;
acpi_status status;
priv = dev_get_drvdata(&wdev->dev);
input.length = priv->req_buf_size - sizeof(u64);
input.pointer = &priv->buf->std;
dev_dbg(&wdev->dev, "evaluating: %u/%u [%x,%x,%x,%x]\n",
priv->buf->std.cmd_class, priv->buf->std.cmd_select,
priv->buf->std.input[0], priv->buf->std.input[1],
priv->buf->std.input[2], priv->buf->std.input[3]);
status = wmidev_evaluate_method(wdev, 0, 1, &input, &output);
if (ACPI_FAILURE(status))
return -EIO;
obj = (union acpi_object *)output.pointer;
if (obj->type != ACPI_TYPE_BUFFER) {
dev_dbg(&wdev->dev, "received type: %d\n", obj->type);
if (obj->type == ACPI_TYPE_INTEGER)
dev_dbg(&wdev->dev, "SMBIOS call failed: %llu\n",
obj->integer.value);
return -EIO;
}
memcpy(&priv->buf->std, obj->buffer.pointer, obj->buffer.length);
dev_dbg(&wdev->dev, "result: [%08x,%08x,%08x,%08x]\n",
priv->buf->std.output[0], priv->buf->std.output[1],
priv->buf->std.output[2], priv->buf->std.output[3]);
return 0;
}
int dell_smbios_wmi_call(struct calling_interface_buffer *buffer)
{
struct wmi_smbios_priv *priv;
size_t difference;
size_t size;
int ret;
mutex_lock(&call_mutex);
priv = get_first_smbios_priv();
if (!priv) {
ret = -ENODEV;
goto out_wmi_call;
}
size = sizeof(struct calling_interface_buffer);
difference = priv->req_buf_size - sizeof(u64) - size;
memset(&priv->buf->ext, 0, difference);
memcpy(&priv->buf->std, buffer, size);
ret = run_smbios_call(priv->wdev);
memcpy(buffer, &priv->buf->std, size);
out_wmi_call:
mutex_unlock(&call_mutex);
return ret;
}
static long dell_smbios_wmi_filter(struct wmi_device *wdev, unsigned int cmd,
struct wmi_ioctl_buffer *arg)
{
struct wmi_smbios_priv *priv;
int ret = 0;
switch (cmd) {
case DELL_WMI_SMBIOS_CMD:
mutex_lock(&call_mutex);
priv = dev_get_drvdata(&wdev->dev);
if (!priv) {
ret = -ENODEV;
goto fail_smbios_cmd;
}
memcpy(priv->buf, arg, priv->req_buf_size);
if (dell_smbios_call_filter(&wdev->dev, &priv->buf->std)) {
dev_err(&wdev->dev, "Invalid call %d/%d:%8x\n",
priv->buf->std.cmd_class,
priv->buf->std.cmd_select,
priv->buf->std.input[0]);
ret = -EFAULT;
goto fail_smbios_cmd;
}
ret = run_smbios_call(priv->wdev);
if (ret)
goto fail_smbios_cmd;
memcpy(arg, priv->buf, priv->req_buf_size);
fail_smbios_cmd:
mutex_unlock(&call_mutex);
break;
default:
ret = -ENOIOCTLCMD;
}
return ret;
}
static int dell_smbios_wmi_probe(struct wmi_device *wdev)
{
struct wmi_driver *wdriver =
container_of(wdev->dev.driver, struct wmi_driver, driver);
struct wmi_smbios_priv *priv;
u32 hotfix;
int count;
int ret;
ret = dell_wmi_get_descriptor_valid();
if (ret)
return ret;
priv = devm_kzalloc(&wdev->dev, sizeof(struct wmi_smbios_priv),
GFP_KERNEL);
if (!priv)
return -ENOMEM;
/* WMI buffer size will be either 4k or 32k depending on machine */
if (!dell_wmi_get_size(&priv->req_buf_size))
return -EPROBE_DEFER;
/* some SMBIOS calls fail unless BIOS contains hotfix */
if (!dell_wmi_get_hotfix(&hotfix))
return -EPROBE_DEFER;
if (!hotfix) {
dev_warn(&wdev->dev,
"WMI SMBIOS userspace interface not supported(%u), try upgrading to a newer BIOS\n",
hotfix);
wdriver->filter_callback = NULL;
}
/* add in the length object we will use internally with ioctl */
priv->req_buf_size += sizeof(u64);
ret = set_required_buffer_size(wdev, priv->req_buf_size);
if (ret)
return ret;
count = get_order(priv->req_buf_size);
priv->buf = (void *)__get_free_pages(GFP_KERNEL, count);
if (!priv->buf)
return -ENOMEM;
/* ID is used by dell-smbios to set priority of drivers */
wdev->dev.id = 1;
ret = dell_smbios_register_device(&wdev->dev, &dell_smbios_wmi_call);
if (ret)
goto fail_register;
priv->wdev = wdev;
dev_set_drvdata(&wdev->dev, priv);
mutex_lock(&list_mutex);
list_add_tail(&priv->list, &wmi_list);
mutex_unlock(&list_mutex);
return 0;
fail_register:
free_pages((unsigned long)priv->buf, count);
return ret;
}
static int dell_smbios_wmi_remove(struct wmi_device *wdev)
{
struct wmi_smbios_priv *priv = dev_get_drvdata(&wdev->dev);
int count;
mutex_lock(&call_mutex);
mutex_lock(&list_mutex);
list_del(&priv->list);
mutex_unlock(&list_mutex);
dell_smbios_unregister_device(&wdev->dev);
count = get_order(priv->req_buf_size);
free_pages((unsigned long)priv->buf, count);
mutex_unlock(&call_mutex);
return 0;
}
static const struct wmi_device_id dell_smbios_wmi_id_table[] = {
{ .guid_string = DELL_WMI_SMBIOS_GUID },
{ },
};
static void parse_b1_table(const struct dmi_header *dm)
{
struct misc_bios_flags_structure *flags =
container_of(dm, struct misc_bios_flags_structure, header);
/* 4 bytes header, 8 bytes flags */
if (dm->length < 12)
return;
if (dm->handle != 0xb100)
return;
if ((flags->flags0 & FLAG_HAS_ACPI_WMI))
wmi_supported = 1;
}
static void find_b1(const struct dmi_header *dm, void *dummy)
{
switch (dm->type) {
case 0xb1: /* misc bios flags */
parse_b1_table(dm);
break;
}
}
static struct wmi_driver dell_smbios_wmi_driver = {
.driver = {
.name = "dell-smbios",
},
.probe = dell_smbios_wmi_probe,
.remove = dell_smbios_wmi_remove,
.id_table = dell_smbios_wmi_id_table,
.filter_callback = dell_smbios_wmi_filter,
};
int init_dell_smbios_wmi(void)
{
dmi_walk(find_b1, NULL);
if (!wmi_supported)
return -ENODEV;
return wmi_driver_register(&dell_smbios_wmi_driver);
}
void exit_dell_smbios_wmi(void)
{
wmi_driver_unregister(&dell_smbios_wmi_driver);
}
MODULE_ALIAS("wmi:" DELL_WMI_SMBIOS_GUID);
|
