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10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/dmi.h>
13#include <linux/list.h>
14#include <linux/module.h>
15#include <linux/mutex.h>
16#include <linux/uaccess.h>
17#include <linux/wmi.h>
18#include "dell-smbios.h"
19#include "dell-wmi-descriptor.h"
20
21static DEFINE_MUTEX(call_mutex);
22static DEFINE_MUTEX(list_mutex);
23static int wmi_supported;
24
25struct misc_bios_flags_structure {
26 struct dmi_header header;
27 u16 flags0;
28} __packed;
29#define FLAG_HAS_ACPI_WMI 0x02
30
31#define DELL_WMI_SMBIOS_GUID "A80593CE-A997-11DA-B012-B622A1EF5492"
32
33struct wmi_smbios_priv {
34 struct dell_wmi_smbios_buffer *buf;
35 struct list_head list;
36 struct wmi_device *wdev;
37 struct device *child;
38 u32 req_buf_size;
39};
40static LIST_HEAD(wmi_list);
41
42static inline struct wmi_smbios_priv *get_first_smbios_priv(void)
43{
44 return list_first_entry_or_null(&wmi_list,
45 struct wmi_smbios_priv,
46 list);
47}
48
49static int run_smbios_call(struct wmi_device *wdev)
50{
51 struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
52 struct wmi_smbios_priv *priv;
53 struct acpi_buffer input;
54 union acpi_object *obj;
55 acpi_status status;
56
57 priv = dev_get_drvdata(&wdev->dev);
58 input.length = priv->req_buf_size - sizeof(u64);
59 input.pointer = &priv->buf->std;
60
61 dev_dbg(&wdev->dev, "evaluating: %u/%u [%x,%x,%x,%x]\n",
62 priv->buf->std.cmd_class, priv->buf->std.cmd_select,
63 priv->buf->std.input[0], priv->buf->std.input[1],
64 priv->buf->std.input[2], priv->buf->std.input[3]);
65
66 status = wmidev_evaluate_method(wdev, 0, 1, &input, &output);
67 if (ACPI_FAILURE(status))
68 return -EIO;
69 obj = (union acpi_object *)output.pointer;
70 if (obj->type != ACPI_TYPE_BUFFER) {
71 dev_dbg(&wdev->dev, "received type: %d\n", obj->type);
72 if (obj->type == ACPI_TYPE_INTEGER)
73 dev_dbg(&wdev->dev, "SMBIOS call failed: %llu\n",
74 obj->integer.value);
75 return -EIO;
76 }
77 memcpy(&priv->buf->std, obj->buffer.pointer, obj->buffer.length);
78 dev_dbg(&wdev->dev, "result: [%08x,%08x,%08x,%08x]\n",
79 priv->buf->std.output[0], priv->buf->std.output[1],
80 priv->buf->std.output[2], priv->buf->std.output[3]);
81
82 return 0;
83}
84
85int dell_smbios_wmi_call(struct calling_interface_buffer *buffer)
86{
87 struct wmi_smbios_priv *priv;
88 size_t difference;
89 size_t size;
90 int ret;
91
92 mutex_lock(&call_mutex);
93 priv = get_first_smbios_priv();
94 if (!priv) {
95 ret = -ENODEV;
96 goto out_wmi_call;
97 }
98
99 size = sizeof(struct calling_interface_buffer);
100 difference = priv->req_buf_size - sizeof(u64) - size;
101
102 memset(&priv->buf->ext, 0, difference);
103 memcpy(&priv->buf->std, buffer, size);
104 ret = run_smbios_call(priv->wdev);
105 memcpy(buffer, &priv->buf->std, size);
106out_wmi_call:
107 mutex_unlock(&call_mutex);
108
109 return ret;
110}
111
112static long dell_smbios_wmi_filter(struct wmi_device *wdev, unsigned int cmd,
113 struct wmi_ioctl_buffer *arg)
114{
115 struct wmi_smbios_priv *priv;
116 int ret = 0;
117
118 switch (cmd) {
119 case DELL_WMI_SMBIOS_CMD:
120 mutex_lock(&call_mutex);
121 priv = dev_get_drvdata(&wdev->dev);
122 if (!priv) {
123 ret = -ENODEV;
124 goto fail_smbios_cmd;
125 }
126 memcpy(priv->buf, arg, priv->req_buf_size);
127 if (dell_smbios_call_filter(&wdev->dev, &priv->buf->std)) {
128 dev_err(&wdev->dev, "Invalid call %d/%d:%8x\n",
129 priv->buf->std.cmd_class,
130 priv->buf->std.cmd_select,
131 priv->buf->std.input[0]);
132 ret = -EFAULT;
133 goto fail_smbios_cmd;
134 }
135 ret = run_smbios_call(priv->wdev);
136 if (ret)
137 goto fail_smbios_cmd;
138 memcpy(arg, priv->buf, priv->req_buf_size);
139fail_smbios_cmd:
140 mutex_unlock(&call_mutex);
141 break;
142 default:
143 ret = -ENOIOCTLCMD;
144 }
145 return ret;
146}
147
148static int dell_smbios_wmi_probe(struct wmi_device *wdev)
149{
150 struct wmi_driver *wdriver =
151 container_of(wdev->dev.driver, struct wmi_driver, driver);
152 struct wmi_smbios_priv *priv;
153 u32 hotfix;
154 int count;
155 int ret;
156
157 ret = dell_wmi_get_descriptor_valid();
158 if (ret)
159 return ret;
160
161 priv = devm_kzalloc(&wdev->dev, sizeof(struct wmi_smbios_priv),
162 GFP_KERNEL);
163 if (!priv)
164 return -ENOMEM;
165
166
167 if (!dell_wmi_get_size(&priv->req_buf_size))
168 return -EPROBE_DEFER;
169
170
171 if (!dell_wmi_get_hotfix(&hotfix))
172 return -EPROBE_DEFER;
173 if (!hotfix) {
174 dev_warn(&wdev->dev,
175 "WMI SMBIOS userspace interface not supported(%u), try upgrading to a newer BIOS\n",
176 hotfix);
177 wdriver->filter_callback = NULL;
178 }
179
180
181 priv->req_buf_size += sizeof(u64);
182 ret = set_required_buffer_size(wdev, priv->req_buf_size);
183 if (ret)
184 return ret;
185
186 count = get_order(priv->req_buf_size);
187 priv->buf = (void *)__get_free_pages(GFP_KERNEL, count);
188 if (!priv->buf)
189 return -ENOMEM;
190
191
192 wdev->dev.id = 1;
193 ret = dell_smbios_register_device(&wdev->dev, &dell_smbios_wmi_call);
194 if (ret)
195 goto fail_register;
196
197 priv->wdev = wdev;
198 dev_set_drvdata(&wdev->dev, priv);
199 mutex_lock(&list_mutex);
200 list_add_tail(&priv->list, &wmi_list);
201 mutex_unlock(&list_mutex);
202
203 return 0;
204
205fail_register:
206 free_pages((unsigned long)priv->buf, count);
207 return ret;
208}
209
210static int dell_smbios_wmi_remove(struct wmi_device *wdev)
211{
212 struct wmi_smbios_priv *priv = dev_get_drvdata(&wdev->dev);
213 int count;
214
215 mutex_lock(&call_mutex);
216 mutex_lock(&list_mutex);
217 list_del(&priv->list);
218 mutex_unlock(&list_mutex);
219 dell_smbios_unregister_device(&wdev->dev);
220 count = get_order(priv->req_buf_size);
221 free_pages((unsigned long)priv->buf, count);
222 mutex_unlock(&call_mutex);
223 return 0;
224}
225
226static const struct wmi_device_id dell_smbios_wmi_id_table[] = {
227 { .guid_string = DELL_WMI_SMBIOS_GUID },
228 { },
229};
230
231static void parse_b1_table(const struct dmi_header *dm)
232{
233 struct misc_bios_flags_structure *flags =
234 container_of(dm, struct misc_bios_flags_structure, header);
235
236
237 if (dm->length < 12)
238 return;
239 if (dm->handle != 0xb100)
240 return;
241 if ((flags->flags0 & FLAG_HAS_ACPI_WMI))
242 wmi_supported = 1;
243}
244
245static void find_b1(const struct dmi_header *dm, void *dummy)
246{
247 switch (dm->type) {
248 case 0xb1:
249 parse_b1_table(dm);
250 break;
251 }
252}
253
254static struct wmi_driver dell_smbios_wmi_driver = {
255 .driver = {
256 .name = "dell-smbios",
257 },
258 .probe = dell_smbios_wmi_probe,
259 .remove = dell_smbios_wmi_remove,
260 .id_table = dell_smbios_wmi_id_table,
261 .filter_callback = dell_smbios_wmi_filter,
262};
263
264int init_dell_smbios_wmi(void)
265{
266 dmi_walk(find_b1, NULL);
267
268 if (!wmi_supported)
269 return -ENODEV;
270
271 return wmi_driver_register(&dell_smbios_wmi_driver);
272}
273
274void exit_dell_smbios_wmi(void)
275{
276 wmi_driver_unregister(&dell_smbios_wmi_driver);
277}
278
279MODULE_ALIAS("wmi:" DELL_WMI_SMBIOS_GUID);
280
