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1a258e67 ML |
1 | /* |
2 | * WMI methods for use with dell-smbios | |
3 | * | |
4 | * Copyright (c) 2017 Dell Inc. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | */ | |
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 | ||
21 | static DEFINE_MUTEX(call_mutex); | |
22 | static DEFINE_MUTEX(list_mutex); | |
23 | static int wmi_supported; | |
24 | ||
25 | struct 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 | ||
1a258e67 ML |
33 | struct 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 | }; | |
40 | static LIST_HEAD(wmi_list); | |
41 | ||
42 | static 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 | ||
49 | static 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 | ||
85 | int 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(); | |
307ab2a9 ML |
94 | if (!priv) { |
95 | ret = -ENODEV; | |
96 | goto out_wmi_call; | |
97 | } | |
1a258e67 ML |
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); | |
307ab2a9 | 106 | out_wmi_call: |
1a258e67 ML |
107 | mutex_unlock(&call_mutex); |
108 | ||
109 | return ret; | |
110 | } | |
111 | ||
f2645fa3 ML |
112 | static 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); | |
139 | fail_smbios_cmd: | |
140 | mutex_unlock(&call_mutex); | |
141 | break; | |
142 | default: | |
143 | ret = -ENOIOCTLCMD; | |
144 | } | |
145 | return ret; | |
146 | } | |
147 | ||
1a258e67 ML |
148 | static int dell_smbios_wmi_probe(struct wmi_device *wdev) |
149 | { | |
4255c30f ML |
150 | struct wmi_driver *wdriver = |
151 | container_of(wdev->dev.driver, struct wmi_driver, driver); | |
1a258e67 | 152 | struct wmi_smbios_priv *priv; |
4255c30f | 153 | u32 hotfix; |
1a258e67 ML |
154 | int count; |
155 | int ret; | |
156 | ||
868b8d33 ML |
157 | ret = dell_wmi_get_descriptor_valid(); |
158 | if (ret) | |
159 | return ret; | |
1a258e67 ML |
160 | |
161 | priv = devm_kzalloc(&wdev->dev, sizeof(struct wmi_smbios_priv), | |
162 | GFP_KERNEL); | |
163 | if (!priv) | |
164 | return -ENOMEM; | |
165 | ||
166 | /* WMI buffer size will be either 4k or 32k depending on machine */ | |
167 | if (!dell_wmi_get_size(&priv->req_buf_size)) | |
168 | return -EPROBE_DEFER; | |
169 | ||
4255c30f ML |
170 | /* some SMBIOS calls fail unless BIOS contains hotfix */ |
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 | ||
f2645fa3 ML |
180 | /* add in the length object we will use internally with ioctl */ |
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 | ||
1a258e67 ML |
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 | /* ID is used by dell-smbios to set priority of drivers */ | |
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 | ||
205 | fail_register: | |
206 | free_pages((unsigned long)priv->buf, count); | |
207 | return ret; | |
208 | } | |
209 | ||
210 | static 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 | ||
226 | static const struct wmi_device_id dell_smbios_wmi_id_table[] = { | |
227 | { .guid_string = DELL_WMI_SMBIOS_GUID }, | |
228 | { }, | |
229 | }; | |
230 | ||
231 | static void __init 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 | /* 4 bytes header, 8 bytes flags */ | |
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 | ||
245 | static void __init find_b1(const struct dmi_header *dm, void *dummy) | |
246 | { | |
247 | switch (dm->type) { | |
248 | case 0xb1: /* misc bios flags */ | |
249 | parse_b1_table(dm); | |
250 | break; | |
251 | } | |
252 | } | |
253 | ||
254 | static 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, | |
f2645fa3 | 261 | .filter_callback = dell_smbios_wmi_filter, |
1a258e67 ML |
262 | }; |
263 | ||
264 | static int __init 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 | ||
274 | static void __exit exit_dell_smbios_wmi(void) | |
275 | { | |
276 | wmi_driver_unregister(&dell_smbios_wmi_driver); | |
277 | } | |
278 | ||
279 | module_init(init_dell_smbios_wmi); | |
280 | module_exit(exit_dell_smbios_wmi); | |
281 | ||
282 | MODULE_ALIAS("wmi:" DELL_WMI_SMBIOS_GUID); | |
283 | MODULE_AUTHOR("Mario Limonciello <mario.limonciello@dell.com>"); | |
284 | MODULE_DESCRIPTION("Dell SMBIOS communications over WMI"); | |
285 | MODULE_LICENSE("GPL"); |