1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Architecture specific sysfs attributes in /sys/kernel |
4 | * |
5 | * Copyright (C) 2007, Intel Corp. |
6 | * Huang Ying <ying.huang@intel.com> |
7 | * Copyright (C) 2013, 2013 Red Hat, Inc. |
8 | * Dave Young <dyoung@redhat.com> |
9 | */ |
10 | |
11 | #include <linux/kobject.h> |
12 | #include <linux/string.h> |
13 | #include <linux/sysfs.h> |
14 | #include <linux/init.h> |
15 | #include <linux/stat.h> |
16 | #include <linux/slab.h> |
17 | #include <linux/mm.h> |
18 | #include <linux/io.h> |
19 | |
20 | #include <asm/setup.h> |
21 | |
22 | static ssize_t version_show(struct kobject *kobj, |
23 | struct kobj_attribute *attr, char *buf) |
24 | { |
25 | return sprintf(buf, fmt: "0x%04x\n" , boot_params.hdr.version); |
26 | } |
27 | |
28 | static struct kobj_attribute boot_params_version_attr = __ATTR_RO(version); |
29 | |
30 | static ssize_t boot_params_data_read(struct file *fp, struct kobject *kobj, |
31 | struct bin_attribute *bin_attr, |
32 | char *buf, loff_t off, size_t count) |
33 | { |
34 | memcpy(buf, (void *)&boot_params + off, count); |
35 | return count; |
36 | } |
37 | |
38 | static struct bin_attribute boot_params_data_attr = { |
39 | .attr = { |
40 | .name = "data" , |
41 | .mode = S_IRUGO, |
42 | }, |
43 | .read = boot_params_data_read, |
44 | .size = sizeof(boot_params), |
45 | }; |
46 | |
47 | static struct attribute *boot_params_version_attrs[] = { |
48 | &boot_params_version_attr.attr, |
49 | NULL, |
50 | }; |
51 | |
52 | static struct bin_attribute *boot_params_data_attrs[] = { |
53 | &boot_params_data_attr, |
54 | NULL, |
55 | }; |
56 | |
57 | static const struct attribute_group boot_params_attr_group = { |
58 | .attrs = boot_params_version_attrs, |
59 | .bin_attrs = boot_params_data_attrs, |
60 | }; |
61 | |
62 | static int kobj_to_setup_data_nr(struct kobject *kobj, int *nr) |
63 | { |
64 | const char *name; |
65 | |
66 | name = kobject_name(kobj); |
67 | return kstrtoint(s: name, base: 10, res: nr); |
68 | } |
69 | |
70 | static int get_setup_data_paddr(int nr, u64 *paddr) |
71 | { |
72 | int i = 0; |
73 | struct setup_data *data; |
74 | u64 pa_data = boot_params.hdr.setup_data; |
75 | |
76 | while (pa_data) { |
77 | if (nr == i) { |
78 | *paddr = pa_data; |
79 | return 0; |
80 | } |
81 | data = memremap(offset: pa_data, size: sizeof(*data), flags: MEMREMAP_WB); |
82 | if (!data) |
83 | return -ENOMEM; |
84 | |
85 | pa_data = data->next; |
86 | memunmap(addr: data); |
87 | i++; |
88 | } |
89 | return -EINVAL; |
90 | } |
91 | |
92 | static int __init get_setup_data_size(int nr, size_t *size) |
93 | { |
94 | u64 pa_data = boot_params.hdr.setup_data, pa_next; |
95 | struct setup_indirect *indirect; |
96 | struct setup_data *data; |
97 | int i = 0; |
98 | u32 len; |
99 | |
100 | while (pa_data) { |
101 | data = memremap(offset: pa_data, size: sizeof(*data), flags: MEMREMAP_WB); |
102 | if (!data) |
103 | return -ENOMEM; |
104 | pa_next = data->next; |
105 | |
106 | if (nr == i) { |
107 | if (data->type == SETUP_INDIRECT) { |
108 | len = sizeof(*data) + data->len; |
109 | memunmap(addr: data); |
110 | data = memremap(offset: pa_data, size: len, flags: MEMREMAP_WB); |
111 | if (!data) |
112 | return -ENOMEM; |
113 | |
114 | indirect = (struct setup_indirect *)data->data; |
115 | |
116 | if (indirect->type != SETUP_INDIRECT) |
117 | *size = indirect->len; |
118 | else |
119 | *size = data->len; |
120 | } else { |
121 | *size = data->len; |
122 | } |
123 | |
124 | memunmap(addr: data); |
125 | return 0; |
126 | } |
127 | |
128 | pa_data = pa_next; |
129 | memunmap(addr: data); |
130 | i++; |
131 | } |
132 | return -EINVAL; |
133 | } |
134 | |
135 | static ssize_t type_show(struct kobject *kobj, |
136 | struct kobj_attribute *attr, char *buf) |
137 | { |
138 | struct setup_indirect *indirect; |
139 | struct setup_data *data; |
140 | int nr, ret; |
141 | u64 paddr; |
142 | u32 len; |
143 | |
144 | ret = kobj_to_setup_data_nr(kobj, nr: &nr); |
145 | if (ret) |
146 | return ret; |
147 | |
148 | ret = get_setup_data_paddr(nr, paddr: &paddr); |
149 | if (ret) |
150 | return ret; |
151 | data = memremap(offset: paddr, size: sizeof(*data), flags: MEMREMAP_WB); |
152 | if (!data) |
153 | return -ENOMEM; |
154 | |
155 | if (data->type == SETUP_INDIRECT) { |
156 | len = sizeof(*data) + data->len; |
157 | memunmap(addr: data); |
158 | data = memremap(offset: paddr, size: len, flags: MEMREMAP_WB); |
159 | if (!data) |
160 | return -ENOMEM; |
161 | |
162 | indirect = (struct setup_indirect *)data->data; |
163 | |
164 | ret = sprintf(buf, fmt: "0x%x\n" , indirect->type); |
165 | } else { |
166 | ret = sprintf(buf, fmt: "0x%x\n" , data->type); |
167 | } |
168 | |
169 | memunmap(addr: data); |
170 | return ret; |
171 | } |
172 | |
173 | static ssize_t setup_data_data_read(struct file *fp, |
174 | struct kobject *kobj, |
175 | struct bin_attribute *bin_attr, |
176 | char *buf, |
177 | loff_t off, size_t count) |
178 | { |
179 | struct setup_indirect *indirect; |
180 | struct setup_data *data; |
181 | int nr, ret = 0; |
182 | u64 paddr, len; |
183 | void *p; |
184 | |
185 | ret = kobj_to_setup_data_nr(kobj, nr: &nr); |
186 | if (ret) |
187 | return ret; |
188 | |
189 | ret = get_setup_data_paddr(nr, paddr: &paddr); |
190 | if (ret) |
191 | return ret; |
192 | data = memremap(offset: paddr, size: sizeof(*data), flags: MEMREMAP_WB); |
193 | if (!data) |
194 | return -ENOMEM; |
195 | |
196 | if (data->type == SETUP_INDIRECT) { |
197 | len = sizeof(*data) + data->len; |
198 | memunmap(addr: data); |
199 | data = memremap(offset: paddr, size: len, flags: MEMREMAP_WB); |
200 | if (!data) |
201 | return -ENOMEM; |
202 | |
203 | indirect = (struct setup_indirect *)data->data; |
204 | |
205 | if (indirect->type != SETUP_INDIRECT) { |
206 | paddr = indirect->addr; |
207 | len = indirect->len; |
208 | } else { |
209 | /* |
210 | * Even though this is technically undefined, return |
211 | * the data as though it is a normal setup_data struct. |
212 | * This will at least allow it to be inspected. |
213 | */ |
214 | paddr += sizeof(*data); |
215 | len = data->len; |
216 | } |
217 | } else { |
218 | paddr += sizeof(*data); |
219 | len = data->len; |
220 | } |
221 | |
222 | if (off > len) { |
223 | ret = -EINVAL; |
224 | goto out; |
225 | } |
226 | |
227 | if (count > len - off) |
228 | count = len - off; |
229 | |
230 | if (!count) |
231 | goto out; |
232 | |
233 | ret = count; |
234 | p = memremap(offset: paddr, size: len, flags: MEMREMAP_WB); |
235 | if (!p) { |
236 | ret = -ENOMEM; |
237 | goto out; |
238 | } |
239 | memcpy(buf, p + off, count); |
240 | memunmap(addr: p); |
241 | out: |
242 | memunmap(addr: data); |
243 | return ret; |
244 | } |
245 | |
246 | static struct kobj_attribute type_attr = __ATTR_RO(type); |
247 | |
248 | static struct bin_attribute data_attr __ro_after_init = { |
249 | .attr = { |
250 | .name = "data" , |
251 | .mode = S_IRUGO, |
252 | }, |
253 | .read = setup_data_data_read, |
254 | }; |
255 | |
256 | static struct attribute *setup_data_type_attrs[] = { |
257 | &type_attr.attr, |
258 | NULL, |
259 | }; |
260 | |
261 | static struct bin_attribute *setup_data_data_attrs[] = { |
262 | &data_attr, |
263 | NULL, |
264 | }; |
265 | |
266 | static const struct attribute_group setup_data_attr_group = { |
267 | .attrs = setup_data_type_attrs, |
268 | .bin_attrs = setup_data_data_attrs, |
269 | }; |
270 | |
271 | static int __init create_setup_data_node(struct kobject *parent, |
272 | struct kobject **kobjp, int nr) |
273 | { |
274 | int ret = 0; |
275 | size_t size; |
276 | struct kobject *kobj; |
277 | char name[16]; /* should be enough for setup_data nodes numbers */ |
278 | snprintf(buf: name, size: 16, fmt: "%d" , nr); |
279 | |
280 | kobj = kobject_create_and_add(name, parent); |
281 | if (!kobj) |
282 | return -ENOMEM; |
283 | |
284 | ret = get_setup_data_size(nr, size: &size); |
285 | if (ret) |
286 | goto out_kobj; |
287 | |
288 | data_attr.size = size; |
289 | ret = sysfs_create_group(kobj, grp: &setup_data_attr_group); |
290 | if (ret) |
291 | goto out_kobj; |
292 | *kobjp = kobj; |
293 | |
294 | return 0; |
295 | out_kobj: |
296 | kobject_put(kobj); |
297 | return ret; |
298 | } |
299 | |
300 | static void __init cleanup_setup_data_node(struct kobject *kobj) |
301 | { |
302 | sysfs_remove_group(kobj, grp: &setup_data_attr_group); |
303 | kobject_put(kobj); |
304 | } |
305 | |
306 | static int __init get_setup_data_total_num(u64 pa_data, int *nr) |
307 | { |
308 | int ret = 0; |
309 | struct setup_data *data; |
310 | |
311 | *nr = 0; |
312 | while (pa_data) { |
313 | *nr += 1; |
314 | data = memremap(offset: pa_data, size: sizeof(*data), flags: MEMREMAP_WB); |
315 | if (!data) { |
316 | ret = -ENOMEM; |
317 | goto out; |
318 | } |
319 | pa_data = data->next; |
320 | memunmap(addr: data); |
321 | } |
322 | |
323 | out: |
324 | return ret; |
325 | } |
326 | |
327 | static int __init create_setup_data_nodes(struct kobject *parent) |
328 | { |
329 | struct kobject *setup_data_kobj, **kobjp; |
330 | u64 pa_data; |
331 | int i, j, nr, ret = 0; |
332 | |
333 | pa_data = boot_params.hdr.setup_data; |
334 | if (!pa_data) |
335 | return 0; |
336 | |
337 | setup_data_kobj = kobject_create_and_add(name: "setup_data" , parent); |
338 | if (!setup_data_kobj) { |
339 | ret = -ENOMEM; |
340 | goto out; |
341 | } |
342 | |
343 | ret = get_setup_data_total_num(pa_data, nr: &nr); |
344 | if (ret) |
345 | goto out_setup_data_kobj; |
346 | |
347 | kobjp = kmalloc_array(n: nr, size: sizeof(*kobjp), GFP_KERNEL); |
348 | if (!kobjp) { |
349 | ret = -ENOMEM; |
350 | goto out_setup_data_kobj; |
351 | } |
352 | |
353 | for (i = 0; i < nr; i++) { |
354 | ret = create_setup_data_node(parent: setup_data_kobj, kobjp: kobjp + i, nr: i); |
355 | if (ret) |
356 | goto out_clean_nodes; |
357 | } |
358 | |
359 | kfree(objp: kobjp); |
360 | return 0; |
361 | |
362 | out_clean_nodes: |
363 | for (j = i - 1; j >= 0; j--) |
364 | cleanup_setup_data_node(kobj: *(kobjp + j)); |
365 | kfree(objp: kobjp); |
366 | out_setup_data_kobj: |
367 | kobject_put(kobj: setup_data_kobj); |
368 | out: |
369 | return ret; |
370 | } |
371 | |
372 | static int __init boot_params_ksysfs_init(void) |
373 | { |
374 | int ret; |
375 | struct kobject *boot_params_kobj; |
376 | |
377 | boot_params_kobj = kobject_create_and_add(name: "boot_params" , |
378 | parent: kernel_kobj); |
379 | if (!boot_params_kobj) { |
380 | ret = -ENOMEM; |
381 | goto out; |
382 | } |
383 | |
384 | ret = sysfs_create_group(kobj: boot_params_kobj, grp: &boot_params_attr_group); |
385 | if (ret) |
386 | goto out_boot_params_kobj; |
387 | |
388 | ret = create_setup_data_nodes(parent: boot_params_kobj); |
389 | if (ret) |
390 | goto out_create_group; |
391 | |
392 | return 0; |
393 | out_create_group: |
394 | sysfs_remove_group(kobj: boot_params_kobj, grp: &boot_params_attr_group); |
395 | out_boot_params_kobj: |
396 | kobject_put(kobj: boot_params_kobj); |
397 | out: |
398 | return ret; |
399 | } |
400 | |
401 | arch_initcall(boot_params_ksysfs_init); |
402 | |