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13#define pr_fmt(fmt) "esrt: " fmt
14
15#include <linux/capability.h>
16#include <linux/device.h>
17#include <linux/efi.h>
18#include <linux/init.h>
19#include <linux/kernel.h>
20#include <linux/kobject.h>
21#include <linux/list.h>
22#include <linux/memblock.h>
23#include <linux/module.h>
24#include <linux/slab.h>
25#include <linux/types.h>
26
27#include <asm/io.h>
28#include <asm/early_ioremap.h>
29
30struct efi_system_resource_entry_v1 {
31 efi_guid_t fw_class;
32 u32 fw_type;
33 u32 fw_version;
34 u32 lowest_supported_fw_version;
35 u32 capsule_flags;
36 u32 last_attempt_version;
37 u32 last_attempt_status;
38};
39
40
41
42
43
44
45
46
47
48
49struct efi_system_resource_table {
50 u32 fw_resource_count;
51 u32 fw_resource_count_max;
52 u64 fw_resource_version;
53 u8 entries[];
54};
55
56static phys_addr_t esrt_data;
57static size_t esrt_data_size;
58
59static struct efi_system_resource_table *esrt;
60
61struct esre_entry {
62 union {
63 struct efi_system_resource_entry_v1 *esre1;
64 } esre;
65
66 struct kobject kobj;
67 struct list_head list;
68};
69
70
71static LIST_HEAD(entry_list);
72
73
74struct esre_attribute {
75 struct attribute attr;
76 ssize_t (*show)(struct esre_entry *entry, char *buf);
77 ssize_t (*store)(struct esre_entry *entry,
78 const char *buf, size_t count);
79};
80
81static struct esre_entry *to_entry(struct kobject *kobj)
82{
83 return container_of(kobj, struct esre_entry, kobj);
84}
85
86static struct esre_attribute *to_attr(struct attribute *attr)
87{
88 return container_of(attr, struct esre_attribute, attr);
89}
90
91static ssize_t esre_attr_show(struct kobject *kobj,
92 struct attribute *_attr, char *buf)
93{
94 struct esre_entry *entry = to_entry(kobj);
95 struct esre_attribute *attr = to_attr(_attr);
96
97
98 if (!capable(CAP_SYS_ADMIN))
99 return -EACCES;
100
101 return attr->show(entry, buf);
102}
103
104static const struct sysfs_ops esre_attr_ops = {
105 .show = esre_attr_show,
106};
107
108
109static ssize_t esre_fw_class_show(struct esre_entry *entry, char *buf)
110{
111 char *str = buf;
112
113 efi_guid_to_str(&entry->esre.esre1->fw_class, str);
114 str += strlen(str);
115 str += sprintf(str, "\n");
116
117 return str - buf;
118}
119
120static struct esre_attribute esre_fw_class = __ATTR(fw_class, 0400,
121 esre_fw_class_show, NULL);
122
123#define esre_attr_decl(name, size, fmt) \
124static ssize_t esre_##name##_show(struct esre_entry *entry, char *buf) \
125{ \
126 return sprintf(buf, fmt "\n", \
127 le##size##_to_cpu(entry->esre.esre1->name)); \
128} \
129\
130static struct esre_attribute esre_##name = __ATTR(name, 0400, \
131 esre_##name##_show, NULL)
132
133esre_attr_decl(fw_type, 32, "%u");
134esre_attr_decl(fw_version, 32, "%u");
135esre_attr_decl(lowest_supported_fw_version, 32, "%u");
136esre_attr_decl(capsule_flags, 32, "0x%x");
137esre_attr_decl(last_attempt_version, 32, "%u");
138esre_attr_decl(last_attempt_status, 32, "%u");
139
140static struct attribute *esre1_attrs[] = {
141 &esre_fw_class.attr,
142 &esre_fw_type.attr,
143 &esre_fw_version.attr,
144 &esre_lowest_supported_fw_version.attr,
145 &esre_capsule_flags.attr,
146 &esre_last_attempt_version.attr,
147 &esre_last_attempt_status.attr,
148 NULL
149};
150static void esre_release(struct kobject *kobj)
151{
152 struct esre_entry *entry = to_entry(kobj);
153
154 list_del(&entry->list);
155 kfree(entry);
156}
157
158static struct kobj_type esre1_ktype = {
159 .release = esre_release,
160 .sysfs_ops = &esre_attr_ops,
161 .default_attrs = esre1_attrs,
162};
163
164
165static struct kobject *esrt_kobj;
166static struct kset *esrt_kset;
167
168static int esre_create_sysfs_entry(void *esre, int entry_num)
169{
170 struct esre_entry *entry;
171 char name[20];
172
173 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
174 if (!entry)
175 return -ENOMEM;
176
177 sprintf(name, "entry%d", entry_num);
178
179 entry->kobj.kset = esrt_kset;
180
181 if (esrt->fw_resource_version == 1) {
182 int rc = 0;
183
184 entry->esre.esre1 = esre;
185 rc = kobject_init_and_add(&entry->kobj, &esre1_ktype, NULL,
186 "%s", name);
187 if (rc) {
188 kfree(entry);
189 return rc;
190 }
191 }
192
193 list_add_tail(&entry->list, &entry_list);
194 return 0;
195}
196
197
198#define esrt_attr_decl(name, size, fmt) \
199static ssize_t esrt_##name##_show(struct kobject *kobj, \
200 struct kobj_attribute *attr, char *buf)\
201{ \
202 return sprintf(buf, fmt "\n", le##size##_to_cpu(esrt->name)); \
203} \
204\
205static struct kobj_attribute esrt_##name = __ATTR(name, 0400, \
206 esrt_##name##_show, NULL)
207
208esrt_attr_decl(fw_resource_count, 32, "%u");
209esrt_attr_decl(fw_resource_count_max, 32, "%u");
210esrt_attr_decl(fw_resource_version, 64, "%llu");
211
212static struct attribute *esrt_attrs[] = {
213 &esrt_fw_resource_count.attr,
214 &esrt_fw_resource_count_max.attr,
215 &esrt_fw_resource_version.attr,
216 NULL,
217};
218
219static inline int esrt_table_exists(void)
220{
221 if (!efi_enabled(EFI_CONFIG_TABLES))
222 return 0;
223 if (efi.esrt == EFI_INVALID_TABLE_ADDR)
224 return 0;
225 return 1;
226}
227
228static umode_t esrt_attr_is_visible(struct kobject *kobj,
229 struct attribute *attr, int n)
230{
231 if (!esrt_table_exists())
232 return 0;
233 return attr->mode;
234}
235
236static struct attribute_group esrt_attr_group = {
237 .attrs = esrt_attrs,
238 .is_visible = esrt_attr_is_visible,
239};
240
241
242
243
244void __init efi_esrt_init(void)
245{
246 void *va;
247 struct efi_system_resource_table tmpesrt;
248 struct efi_system_resource_entry_v1 *v1_entries;
249 size_t size, max, entry_size, entries_size;
250 efi_memory_desc_t md;
251 int rc;
252 phys_addr_t end;
253
254 pr_debug("esrt-init: loading.\n");
255 if (!esrt_table_exists())
256 return;
257
258 rc = efi_mem_desc_lookup(efi.esrt, &md);
259 if (rc < 0) {
260 pr_err("ESRT header is not in the memory map.\n");
261 return;
262 }
263
264 max = efi_mem_desc_end(&md);
265 if (max < efi.esrt) {
266 pr_err("EFI memory descriptor is invalid. (esrt: %p max: %p)\n",
267 (void *)efi.esrt, (void *)max);
268 return;
269 }
270
271 size = sizeof(*esrt);
272 max -= efi.esrt;
273
274 if (max < size) {
275 pr_err("ESRT header doen't fit on single memory map entry. (size: %zu max: %zu)\n",
276 size, max);
277 return;
278 }
279
280 va = early_memremap(efi.esrt, size);
281 if (!va) {
282 pr_err("early_memremap(%p, %zu) failed.\n", (void *)efi.esrt,
283 size);
284 return;
285 }
286
287 memcpy(&tmpesrt, va, sizeof(tmpesrt));
288
289 if (tmpesrt.fw_resource_version == 1) {
290 entry_size = sizeof (*v1_entries);
291 } else {
292 pr_err("Unsupported ESRT version %lld.\n",
293 tmpesrt.fw_resource_version);
294 return;
295 }
296
297 if (tmpesrt.fw_resource_count > 0 && max - size < entry_size) {
298 pr_err("ESRT memory map entry can only hold the header. (max: %zu size: %zu)\n",
299 max - size, entry_size);
300 goto err_memunmap;
301 }
302
303
304
305
306
307
308
309
310 if (tmpesrt.fw_resource_count > 128) {
311 pr_err("ESRT says fw_resource_count has very large value %d.\n",
312 tmpesrt.fw_resource_count);
313 goto err_memunmap;
314 }
315
316
317
318
319
320 entries_size = tmpesrt.fw_resource_count * entry_size;
321 if (max < size + entries_size) {
322 pr_err("ESRT does not fit on single memory map entry (size: %zu max: %zu)\n",
323 size, max);
324 goto err_memunmap;
325 }
326
327
328 early_memunmap(va, size);
329 size += entries_size;
330 va = early_memremap(efi.esrt, size);
331 if (!va) {
332 pr_err("early_memremap(%p, %zu) failed.\n", (void *)efi.esrt,
333 size);
334 return;
335 }
336
337 esrt_data = (phys_addr_t)efi.esrt;
338 esrt_data_size = size;
339
340 end = esrt_data + size;
341 pr_info("Reserving ESRT space from %pa to %pa.\n", &esrt_data, &end);
342 memblock_reserve(esrt_data, esrt_data_size);
343
344 pr_debug("esrt-init: loaded.\n");
345err_memunmap:
346 early_memunmap(va, size);
347}
348
349static int __init register_entries(void)
350{
351 struct efi_system_resource_entry_v1 *v1_entries = (void *)esrt->entries;
352 int i, rc;
353
354 if (!esrt_table_exists())
355 return 0;
356
357 for (i = 0; i < le32_to_cpu(esrt->fw_resource_count); i++) {
358 void *esre = NULL;
359 if (esrt->fw_resource_version == 1) {
360 esre = &v1_entries[i];
361 } else {
362 pr_err("Unsupported ESRT version %lld.\n",
363 esrt->fw_resource_version);
364 return -EINVAL;
365 }
366
367 rc = esre_create_sysfs_entry(esre, i);
368 if (rc < 0) {
369 pr_err("ESRT entry creation failed with error %d.\n",
370 rc);
371 return rc;
372 }
373 }
374 return 0;
375}
376
377static void cleanup_entry_list(void)
378{
379 struct esre_entry *entry, *next;
380
381 list_for_each_entry_safe(entry, next, &entry_list, list) {
382 kobject_put(&entry->kobj);
383 }
384}
385
386static int __init esrt_sysfs_init(void)
387{
388 int error;
389 struct efi_system_resource_table __iomem *ioesrt;
390
391 pr_debug("esrt-sysfs: loading.\n");
392 if (!esrt_data || !esrt_data_size)
393 return -ENOSYS;
394
395 ioesrt = ioremap(esrt_data, esrt_data_size);
396 if (!ioesrt) {
397 pr_err("ioremap(%pa, %zu) failed.\n", &esrt_data,
398 esrt_data_size);
399 return -ENOMEM;
400 }
401
402 esrt = kmalloc(esrt_data_size, GFP_KERNEL);
403 if (!esrt) {
404 pr_err("kmalloc failed. (wanted %zu bytes)\n", esrt_data_size);
405 iounmap(ioesrt);
406 return -ENOMEM;
407 }
408
409 memcpy_fromio(esrt, ioesrt, esrt_data_size);
410
411 esrt_kobj = kobject_create_and_add("esrt", efi_kobj);
412 if (!esrt_kobj) {
413 pr_err("Firmware table registration failed.\n");
414 error = -ENOMEM;
415 goto err;
416 }
417
418 error = sysfs_create_group(esrt_kobj, &esrt_attr_group);
419 if (error) {
420 pr_err("Sysfs attribute export failed with error %d.\n",
421 error);
422 goto err_remove_esrt;
423 }
424
425 esrt_kset = kset_create_and_add("entries", NULL, esrt_kobj);
426 if (!esrt_kset) {
427 pr_err("kset creation failed.\n");
428 error = -ENOMEM;
429 goto err_remove_group;
430 }
431
432 error = register_entries();
433 if (error)
434 goto err_cleanup_list;
435
436 memblock_remove(esrt_data, esrt_data_size);
437
438 pr_debug("esrt-sysfs: loaded.\n");
439
440 return 0;
441err_cleanup_list:
442 cleanup_entry_list();
443 kset_unregister(esrt_kset);
444err_remove_group:
445 sysfs_remove_group(esrt_kobj, &esrt_attr_group);
446err_remove_esrt:
447 kobject_put(esrt_kobj);
448err:
449 kfree(esrt);
450 esrt = NULL;
451 return error;
452}
453
454static void __exit esrt_sysfs_exit(void)
455{
456 pr_debug("esrt-sysfs: unloading.\n");
457 cleanup_entry_list();
458 kset_unregister(esrt_kset);
459 sysfs_remove_group(esrt_kobj, &esrt_attr_group);
460 kfree(esrt);
461 esrt = NULL;
462 kobject_del(esrt_kobj);
463 kobject_put(esrt_kobj);
464}
465
466module_init(esrt_sysfs_init);
467module_exit(esrt_sysfs_exit);
468
469MODULE_AUTHOR("Peter Jones <pjones@redhat.com>");
470MODULE_DESCRIPTION("EFI System Resource Table support");
471MODULE_LICENSE("GPL");
472
