]>
Commit | Line | Data |
---|---|---|
d9523678 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
69ac9cd6 BW |
2 | /* |
3 | * linux/drivers/firmware/memmap.c | |
4 | * Copyright (C) 2008 SUSE LINUX Products GmbH | |
97bef7dd | 5 | * by Bernhard Walle <bernhard.walle@gmx.de> |
69ac9cd6 BW |
6 | */ |
7 | ||
8 | #include <linux/string.h> | |
9 | #include <linux/firmware-map.h> | |
10 | #include <linux/kernel.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/types.h> | |
57c8a661 | 13 | #include <linux/memblock.h> |
5a0e3ad6 | 14 | #include <linux/slab.h> |
46c66c4b | 15 | #include <linux/mm.h> |
69ac9cd6 BW |
16 | |
17 | /* | |
18 | * Data types ------------------------------------------------------------------ | |
19 | */ | |
20 | ||
21 | /* | |
22 | * Firmware map entry. Because firmware memory maps are flat and not | |
23 | * hierarchical, it's ok to organise them in a linked list. No parent | |
24 | * information is necessary as for the resource tree. | |
25 | */ | |
26 | struct firmware_map_entry { | |
3b0fde0f YL |
27 | /* |
28 | * start and end must be u64 rather than resource_size_t, because e820 | |
29 | * resources can lie at addresses above 4G. | |
30 | */ | |
31 | u64 start; /* start of the memory range */ | |
32 | u64 end; /* end of the memory range (incl.) */ | |
69ac9cd6 BW |
33 | const char *type; /* type of the memory range */ |
34 | struct list_head list; /* entry for the linked list */ | |
35 | struct kobject kobj; /* kobject for each entry */ | |
36 | }; | |
37 | ||
38 | /* | |
39 | * Forward declarations -------------------------------------------------------- | |
40 | */ | |
41 | static ssize_t memmap_attr_show(struct kobject *kobj, | |
42 | struct attribute *attr, char *buf); | |
43 | static ssize_t start_show(struct firmware_map_entry *entry, char *buf); | |
44 | static ssize_t end_show(struct firmware_map_entry *entry, char *buf); | |
45 | static ssize_t type_show(struct firmware_map_entry *entry, char *buf); | |
46 | ||
46c66c4b YI |
47 | static struct firmware_map_entry * __meminit |
48 | firmware_map_find_entry(u64 start, u64 end, const char *type); | |
49 | ||
69ac9cd6 BW |
50 | /* |
51 | * Static data ----------------------------------------------------------------- | |
52 | */ | |
53 | ||
54 | struct memmap_attribute { | |
55 | struct attribute attr; | |
56 | ssize_t (*show)(struct firmware_map_entry *entry, char *buf); | |
57 | }; | |
58 | ||
da2bdf9a RK |
59 | static struct memmap_attribute memmap_start_attr = __ATTR_RO(start); |
60 | static struct memmap_attribute memmap_end_attr = __ATTR_RO(end); | |
61 | static struct memmap_attribute memmap_type_attr = __ATTR_RO(type); | |
69ac9cd6 BW |
62 | |
63 | /* | |
64 | * These are default attributes that are added for every memmap entry. | |
65 | */ | |
66 | static struct attribute *def_attrs[] = { | |
67 | &memmap_start_attr.attr, | |
68 | &memmap_end_attr.attr, | |
69 | &memmap_type_attr.attr, | |
70 | NULL | |
71 | }; | |
72 | ||
52cf25d0 | 73 | static const struct sysfs_ops memmap_attr_ops = { |
69ac9cd6 BW |
74 | .show = memmap_attr_show, |
75 | }; | |
76 | ||
46c66c4b YI |
77 | /* Firmware memory map entries. */ |
78 | static LIST_HEAD(map_entries); | |
79 | static DEFINE_SPINLOCK(map_entries_lock); | |
80 | ||
81 | /* | |
82 | * For memory hotplug, there is no way to free memory map entries allocated | |
83 | * by boot mem after the system is up. So when we hot-remove memory whose | |
84 | * map entry is allocated by bootmem, we need to remember the storage and | |
85 | * reuse it when the memory is hot-added again. | |
86 | */ | |
87 | static LIST_HEAD(map_entries_bootmem); | |
88 | static DEFINE_SPINLOCK(map_entries_bootmem_lock); | |
89 | ||
90 | ||
91 | static inline struct firmware_map_entry * | |
92 | to_memmap_entry(struct kobject *kobj) | |
93 | { | |
94 | return container_of(kobj, struct firmware_map_entry, kobj); | |
95 | } | |
96 | ||
97 | static void __meminit release_firmware_map_entry(struct kobject *kobj) | |
98 | { | |
99 | struct firmware_map_entry *entry = to_memmap_entry(kobj); | |
100 | ||
101 | if (PageReserved(virt_to_page(entry))) { | |
102 | /* | |
103 | * Remember the storage allocated by bootmem, and reuse it when | |
104 | * the memory is hot-added again. The entry will be added to | |
105 | * map_entries_bootmem here, and deleted from &map_entries in | |
106 | * firmware_map_remove_entry(). | |
107 | */ | |
7a6f93b0 YI |
108 | spin_lock(&map_entries_bootmem_lock); |
109 | list_add(&entry->list, &map_entries_bootmem); | |
110 | spin_unlock(&map_entries_bootmem_lock); | |
46c66c4b YI |
111 | |
112 | return; | |
113 | } | |
114 | ||
115 | kfree(entry); | |
116 | } | |
117 | ||
118 | static struct kobj_type __refdata memmap_ktype = { | |
119 | .release = release_firmware_map_entry, | |
69ac9cd6 BW |
120 | .sysfs_ops = &memmap_attr_ops, |
121 | .default_attrs = def_attrs, | |
122 | }; | |
123 | ||
124 | /* | |
125 | * Registration functions ------------------------------------------------------ | |
126 | */ | |
127 | ||
69ac9cd6 | 128 | /** |
31bad924 | 129 | * firmware_map_add_entry() - Does the real work to add a firmware memmap entry. |
69ac9cd6 | 130 | * @start: Start of the memory range. |
4ed940d4 | 131 | * @end: End of the memory range (exclusive). |
69ac9cd6 BW |
132 | * @type: Type of the memory range. |
133 | * @entry: Pre-allocated (either kmalloc() or bootmem allocator), uninitialised | |
134 | * entry. | |
31bad924 BW |
135 | * |
136 | * Common implementation of firmware_map_add() and firmware_map_add_early() | |
137 | * which expects a pre-allocated struct firmware_map_entry. | |
cbdc2810 MS |
138 | * |
139 | * Return: 0 always | |
140 | */ | |
3b0fde0f | 141 | static int firmware_map_add_entry(u64 start, u64 end, |
69ac9cd6 BW |
142 | const char *type, |
143 | struct firmware_map_entry *entry) | |
144 | { | |
145 | BUG_ON(start > end); | |
146 | ||
147 | entry->start = start; | |
4ed940d4 | 148 | entry->end = end - 1; |
69ac9cd6 BW |
149 | entry->type = type; |
150 | INIT_LIST_HEAD(&entry->list); | |
151 | kobject_init(&entry->kobj, &memmap_ktype); | |
152 | ||
46c66c4b | 153 | spin_lock(&map_entries_lock); |
69ac9cd6 | 154 | list_add_tail(&entry->list, &map_entries); |
46c66c4b | 155 | spin_unlock(&map_entries_lock); |
69ac9cd6 BW |
156 | |
157 | return 0; | |
158 | } | |
159 | ||
46c66c4b YI |
160 | /** |
161 | * firmware_map_remove_entry() - Does the real work to remove a firmware | |
162 | * memmap entry. | |
163 | * @entry: removed entry. | |
164 | * | |
165 | * The caller must hold map_entries_lock, and release it properly. | |
cbdc2810 | 166 | */ |
46c66c4b YI |
167 | static inline void firmware_map_remove_entry(struct firmware_map_entry *entry) |
168 | { | |
169 | list_del(&entry->list); | |
170 | } | |
171 | ||
d96ae530 AM |
172 | /* |
173 | * Add memmap entry on sysfs | |
174 | */ | |
175 | static int add_sysfs_fw_map_entry(struct firmware_map_entry *entry) | |
176 | { | |
177 | static int map_entries_nr; | |
178 | static struct kset *mmap_kset; | |
179 | ||
22880ebe YI |
180 | if (entry->kobj.state_in_sysfs) |
181 | return -EEXIST; | |
182 | ||
d96ae530 AM |
183 | if (!mmap_kset) { |
184 | mmap_kset = kset_create_and_add("memmap", NULL, firmware_kobj); | |
185 | if (!mmap_kset) | |
186 | return -ENOMEM; | |
187 | } | |
188 | ||
189 | entry->kobj.kset = mmap_kset; | |
190 | if (kobject_add(&entry->kobj, NULL, "%d", map_entries_nr++)) | |
191 | kobject_put(&entry->kobj); | |
192 | ||
193 | return 0; | |
194 | } | |
195 | ||
46c66c4b YI |
196 | /* |
197 | * Remove memmap entry on sysfs | |
198 | */ | |
199 | static inline void remove_sysfs_fw_map_entry(struct firmware_map_entry *entry) | |
200 | { | |
201 | kobject_put(&entry->kobj); | |
202 | } | |
203 | ||
cbdc2810 | 204 | /** |
46c66c4b YI |
205 | * firmware_map_find_entry_in_list() - Search memmap entry in a given list. |
206 | * @start: Start of the memory range. | |
207 | * @end: End of the memory range (exclusive). | |
208 | * @type: Type of the memory range. | |
209 | * @list: In which to find the entry. | |
210 | * | |
211 | * This function is to find the memmap entey of a given memory range in a | |
212 | * given list. The caller must hold map_entries_lock, and must not release | |
213 | * the lock until the processing of the returned entry has completed. | |
214 | * | |
215 | * Return: Pointer to the entry to be found on success, or NULL on failure. | |
216 | */ | |
217 | static struct firmware_map_entry * __meminit | |
218 | firmware_map_find_entry_in_list(u64 start, u64 end, const char *type, | |
219 | struct list_head *list) | |
220 | { | |
221 | struct firmware_map_entry *entry; | |
222 | ||
223 | list_for_each_entry(entry, list, list) | |
224 | if ((entry->start == start) && (entry->end == end) && | |
225 | (!strcmp(entry->type, type))) { | |
226 | return entry; | |
227 | } | |
228 | ||
229 | return NULL; | |
230 | } | |
231 | ||
cbdc2810 | 232 | /** |
46c66c4b YI |
233 | * firmware_map_find_entry() - Search memmap entry in map_entries. |
234 | * @start: Start of the memory range. | |
235 | * @end: End of the memory range (exclusive). | |
236 | * @type: Type of the memory range. | |
237 | * | |
238 | * This function is to find the memmap entey of a given memory range. | |
239 | * The caller must hold map_entries_lock, and must not release the lock | |
240 | * until the processing of the returned entry has completed. | |
241 | * | |
242 | * Return: Pointer to the entry to be found on success, or NULL on failure. | |
243 | */ | |
244 | static struct firmware_map_entry * __meminit | |
245 | firmware_map_find_entry(u64 start, u64 end, const char *type) | |
246 | { | |
247 | return firmware_map_find_entry_in_list(start, end, type, &map_entries); | |
248 | } | |
249 | ||
cbdc2810 | 250 | /** |
46c66c4b YI |
251 | * firmware_map_find_entry_bootmem() - Search memmap entry in map_entries_bootmem. |
252 | * @start: Start of the memory range. | |
253 | * @end: End of the memory range (exclusive). | |
254 | * @type: Type of the memory range. | |
255 | * | |
256 | * This function is similar to firmware_map_find_entry except that it find the | |
257 | * given entry in map_entries_bootmem. | |
258 | * | |
259 | * Return: Pointer to the entry to be found on success, or NULL on failure. | |
260 | */ | |
261 | static struct firmware_map_entry * __meminit | |
262 | firmware_map_find_entry_bootmem(u64 start, u64 end, const char *type) | |
263 | { | |
264 | return firmware_map_find_entry_in_list(start, end, type, | |
265 | &map_entries_bootmem); | |
266 | } | |
267 | ||
31bad924 | 268 | /** |
d96ae530 AM |
269 | * firmware_map_add_hotplug() - Adds a firmware mapping entry when we do |
270 | * memory hotplug. | |
31bad924 | 271 | * @start: Start of the memory range. |
4ed940d4 | 272 | * @end: End of the memory range (exclusive) |
31bad924 BW |
273 | * @type: Type of the memory range. |
274 | * | |
d96ae530 AM |
275 | * Adds a firmware mapping entry. This function is for memory hotplug, it is |
276 | * similar to function firmware_map_add_early(). The only difference is that | |
277 | * it will create the syfs entry dynamically. | |
31bad924 | 278 | * |
cbdc2810 MS |
279 | * Return: 0 on success, or -ENOMEM if no memory could be allocated. |
280 | */ | |
d96ae530 | 281 | int __meminit firmware_map_add_hotplug(u64 start, u64 end, const char *type) |
69ac9cd6 BW |
282 | { |
283 | struct firmware_map_entry *entry; | |
284 | ||
f0093ede YI |
285 | entry = firmware_map_find_entry(start, end - 1, type); |
286 | if (entry) | |
287 | return 0; | |
288 | ||
49c8b24d | 289 | entry = firmware_map_find_entry_bootmem(start, end - 1, type); |
46c66c4b YI |
290 | if (!entry) { |
291 | entry = kzalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC); | |
292 | if (!entry) | |
293 | return -ENOMEM; | |
294 | } else { | |
295 | /* Reuse storage allocated by bootmem. */ | |
296 | spin_lock(&map_entries_bootmem_lock); | |
297 | list_del(&entry->list); | |
298 | spin_unlock(&map_entries_bootmem_lock); | |
299 | ||
300 | memset(entry, 0, sizeof(*entry)); | |
301 | } | |
69ac9cd6 | 302 | |
d96ae530 AM |
303 | firmware_map_add_entry(start, end, type, entry); |
304 | /* create the memmap entry */ | |
305 | add_sysfs_fw_map_entry(entry); | |
306 | ||
307 | return 0; | |
69ac9cd6 BW |
308 | } |
309 | ||
31bad924 BW |
310 | /** |
311 | * firmware_map_add_early() - Adds a firmware mapping entry. | |
312 | * @start: Start of the memory range. | |
4ed940d4 | 313 | * @end: End of the memory range. |
31bad924 BW |
314 | * @type: Type of the memory range. |
315 | * | |
316 | * Adds a firmware mapping entry. This function uses the bootmem allocator | |
d96ae530 | 317 | * for memory allocation. |
31bad924 BW |
318 | * |
319 | * That function must be called before late_initcall. | |
320 | * | |
cbdc2810 MS |
321 | * Return: 0 on success, or -ENOMEM if no memory could be allocated. |
322 | */ | |
3b0fde0f | 323 | int __init firmware_map_add_early(u64 start, u64 end, const char *type) |
69ac9cd6 BW |
324 | { |
325 | struct firmware_map_entry *entry; | |
326 | ||
26fb3dae | 327 | entry = memblock_alloc(sizeof(struct firmware_map_entry), |
7e1c4e27 | 328 | SMP_CACHE_BYTES); |
31bad924 | 329 | if (WARN_ON(!entry)) |
69ac9cd6 BW |
330 | return -ENOMEM; |
331 | ||
332 | return firmware_map_add_entry(start, end, type, entry); | |
333 | } | |
334 | ||
46c66c4b YI |
335 | /** |
336 | * firmware_map_remove() - remove a firmware mapping entry | |
337 | * @start: Start of the memory range. | |
338 | * @end: End of the memory range. | |
339 | * @type: Type of the memory range. | |
340 | * | |
341 | * removes a firmware mapping entry. | |
342 | * | |
cbdc2810 MS |
343 | * Return: 0 on success, or -EINVAL if no entry. |
344 | */ | |
46c66c4b YI |
345 | int __meminit firmware_map_remove(u64 start, u64 end, const char *type) |
346 | { | |
347 | struct firmware_map_entry *entry; | |
348 | ||
349 | spin_lock(&map_entries_lock); | |
350 | entry = firmware_map_find_entry(start, end - 1, type); | |
351 | if (!entry) { | |
352 | spin_unlock(&map_entries_lock); | |
353 | return -EINVAL; | |
354 | } | |
355 | ||
356 | firmware_map_remove_entry(entry); | |
357 | spin_unlock(&map_entries_lock); | |
358 | ||
359 | /* remove the memmap entry */ | |
360 | remove_sysfs_fw_map_entry(entry); | |
361 | ||
362 | return 0; | |
363 | } | |
364 | ||
69ac9cd6 BW |
365 | /* |
366 | * Sysfs functions ------------------------------------------------------------- | |
367 | */ | |
368 | ||
369 | static ssize_t start_show(struct firmware_map_entry *entry, char *buf) | |
370 | { | |
78681ac0 RD |
371 | return snprintf(buf, PAGE_SIZE, "0x%llx\n", |
372 | (unsigned long long)entry->start); | |
69ac9cd6 BW |
373 | } |
374 | ||
375 | static ssize_t end_show(struct firmware_map_entry *entry, char *buf) | |
376 | { | |
78681ac0 RD |
377 | return snprintf(buf, PAGE_SIZE, "0x%llx\n", |
378 | (unsigned long long)entry->end); | |
69ac9cd6 BW |
379 | } |
380 | ||
381 | static ssize_t type_show(struct firmware_map_entry *entry, char *buf) | |
382 | { | |
383 | return snprintf(buf, PAGE_SIZE, "%s\n", entry->type); | |
384 | } | |
385 | ||
46c66c4b YI |
386 | static inline struct memmap_attribute *to_memmap_attr(struct attribute *attr) |
387 | { | |
388 | return container_of(attr, struct memmap_attribute, attr); | |
389 | } | |
69ac9cd6 BW |
390 | |
391 | static ssize_t memmap_attr_show(struct kobject *kobj, | |
392 | struct attribute *attr, char *buf) | |
393 | { | |
394 | struct firmware_map_entry *entry = to_memmap_entry(kobj); | |
395 | struct memmap_attribute *memmap_attr = to_memmap_attr(attr); | |
396 | ||
397 | return memmap_attr->show(entry, buf); | |
398 | } | |
399 | ||
400 | /* | |
401 | * Initialises stuff and adds the entries in the map_entries list to | |
402 | * sysfs. Important is that firmware_map_add() and firmware_map_add_early() | |
31bad924 BW |
403 | * must be called before late_initcall. That's just because that function |
404 | * is called as late_initcall() function, which means that if you call | |
405 | * firmware_map_add() or firmware_map_add_early() afterwards, the entries | |
406 | * are not added to sysfs. | |
69ac9cd6 | 407 | */ |
bac71696 | 408 | static int __init firmware_memmap_init(void) |
69ac9cd6 | 409 | { |
69ac9cd6 | 410 | struct firmware_map_entry *entry; |
69ac9cd6 | 411 | |
d96ae530 AM |
412 | list_for_each_entry(entry, &map_entries, list) |
413 | add_sysfs_fw_map_entry(entry); | |
69ac9cd6 BW |
414 | |
415 | return 0; | |
416 | } | |
bac71696 | 417 | late_initcall(firmware_memmap_init); |
69ac9cd6 | 418 |