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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/drivers/firmware/memmap.c
4 * Copyright (C) 2008 SUSE LINUX Products GmbH
5 * by Bernhard Walle <bernhard.walle@gmx.de>
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>
13#include <linux/memblock.h>
14#include <linux/slab.h>
15#include <linux/mm.h>
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 */
26struct firmware_map_entry {
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.) */
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 */
41static ssize_t memmap_attr_show(struct kobject *kobj,
42 struct attribute *attr, char *buf);
43static ssize_t start_show(struct firmware_map_entry *entry, char *buf);
44static ssize_t end_show(struct firmware_map_entry *entry, char *buf);
45static ssize_t type_show(struct firmware_map_entry *entry, char *buf);
46
47static struct firmware_map_entry * __meminit
48firmware_map_find_entry(u64 start, u64 end, const char *type);
49
50/*
51 * Static data -----------------------------------------------------------------
52 */
53
54struct memmap_attribute {
55 struct attribute attr;
56 ssize_t (*show)(struct firmware_map_entry *entry, char *buf);
57};
58
59static struct memmap_attribute memmap_start_attr = __ATTR_RO(start);
60static struct memmap_attribute memmap_end_attr = __ATTR_RO(end);
61static struct memmap_attribute memmap_type_attr = __ATTR_RO(type);
62
63/*
64 * These are default attributes that are added for every memmap entry.
65 */
66static struct attribute *def_attrs[] = {
67 &memmap_start_attr.attr,
68 &memmap_end_attr.attr,
69 &memmap_type_attr.attr,
70 NULL
71};
72
73static const struct sysfs_ops memmap_attr_ops = {
74 .show = memmap_attr_show,
75};
76
77/* Firmware memory map entries. */
78static LIST_HEAD(map_entries);
79static 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 */
87static LIST_HEAD(map_entries_bootmem);
88static DEFINE_SPINLOCK(map_entries_bootmem_lock);
89
90
91static inline struct firmware_map_entry *
92to_memmap_entry(struct kobject *kobj)
93{
94 return container_of(kobj, struct firmware_map_entry, kobj);
95}
96
97static 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 */
108 spin_lock(&map_entries_bootmem_lock);
109 list_add(&entry->list, &map_entries_bootmem);
110 spin_unlock(&map_entries_bootmem_lock);
111
112 return;
113 }
114
115 kfree(entry);
116}
117
118static struct kobj_type __refdata memmap_ktype = {
119 .release = release_firmware_map_entry,
120 .sysfs_ops = &memmap_attr_ops,
121 .default_attrs = def_attrs,
122};
123
124/*
125 * Registration functions ------------------------------------------------------
126 */
127
128/**
129 * firmware_map_add_entry() - Does the real work to add a firmware memmap entry.
130 * @start: Start of the memory range.
131 * @end: End of the memory range (exclusive).
132 * @type: Type of the memory range.
133 * @entry: Pre-allocated (either kmalloc() or bootmem allocator), uninitialised
134 * entry.
135 *
136 * Common implementation of firmware_map_add() and firmware_map_add_early()
137 * which expects a pre-allocated struct firmware_map_entry.
138 *
139 * Return: 0 always
140 */
141static int firmware_map_add_entry(u64 start, u64 end,
142 const char *type,
143 struct firmware_map_entry *entry)
144{
145 BUG_ON(start > end);
146
147 entry->start = start;
148 entry->end = end - 1;
149 entry->type = type;
150 INIT_LIST_HEAD(&entry->list);
151 kobject_init(&entry->kobj, &memmap_ktype);
152
153 spin_lock(&map_entries_lock);
154 list_add_tail(&entry->list, &map_entries);
155 spin_unlock(&map_entries_lock);
156
157 return 0;
158}
159
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.
166 */
167static inline void firmware_map_remove_entry(struct firmware_map_entry *entry)
168{
169 list_del(&entry->list);
170}
171
172/*
173 * Add memmap entry on sysfs
174 */
175static 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
180 if (entry->kobj.state_in_sysfs)
181 return -EEXIST;
182
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
196/*
197 * Remove memmap entry on sysfs
198 */
199static inline void remove_sysfs_fw_map_entry(struct firmware_map_entry *entry)
200{
201 kobject_put(&entry->kobj);
202}
203
204/**
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 */
217static struct firmware_map_entry * __meminit
218firmware_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
232/**
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 */
244static struct firmware_map_entry * __meminit
245firmware_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
250/**
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 */
261static struct firmware_map_entry * __meminit
262firmware_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
268/**
269 * firmware_map_add_hotplug() - Adds a firmware mapping entry when we do
270 * memory hotplug.
271 * @start: Start of the memory range.
272 * @end: End of the memory range (exclusive)
273 * @type: Type of the memory range.
274 *
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.
278 *
279 * Return: 0 on success, or -ENOMEM if no memory could be allocated.
280 */
281int __meminit firmware_map_add_hotplug(u64 start, u64 end, const char *type)
282{
283 struct firmware_map_entry *entry;
284
285 entry = firmware_map_find_entry(start, end - 1, type);
286 if (entry)
287 return 0;
288
289 entry = firmware_map_find_entry_bootmem(start, end - 1, type);
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 }
302
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;
308}
309
310/**
311 * firmware_map_add_early() - Adds a firmware mapping entry.
312 * @start: Start of the memory range.
313 * @end: End of the memory range.
314 * @type: Type of the memory range.
315 *
316 * Adds a firmware mapping entry. This function uses the bootmem allocator
317 * for memory allocation.
318 *
319 * That function must be called before late_initcall.
320 *
321 * Return: 0 on success, or -ENOMEM if no memory could be allocated.
322 */
323int __init firmware_map_add_early(u64 start, u64 end, const char *type)
324{
325 struct firmware_map_entry *entry;
326
327 entry = memblock_alloc(sizeof(struct firmware_map_entry),
328 SMP_CACHE_BYTES);
329 if (WARN_ON(!entry))
330 return -ENOMEM;
331
332 return firmware_map_add_entry(start, end, type, entry);
333}
334
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 *
343 * Return: 0 on success, or -EINVAL if no entry.
344 */
345int __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
365/*
366 * Sysfs functions -------------------------------------------------------------
367 */
368
369static ssize_t start_show(struct firmware_map_entry *entry, char *buf)
370{
371 return snprintf(buf, PAGE_SIZE, "0x%llx\n",
372 (unsigned long long)entry->start);
373}
374
375static ssize_t end_show(struct firmware_map_entry *entry, char *buf)
376{
377 return snprintf(buf, PAGE_SIZE, "0x%llx\n",
378 (unsigned long long)entry->end);
379}
380
381static ssize_t type_show(struct firmware_map_entry *entry, char *buf)
382{
383 return snprintf(buf, PAGE_SIZE, "%s\n", entry->type);
384}
385
386static inline struct memmap_attribute *to_memmap_attr(struct attribute *attr)
387{
388 return container_of(attr, struct memmap_attribute, attr);
389}
390
391static 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()
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.
407 */
408static int __init firmware_memmap_init(void)
409{
410 struct firmware_map_entry *entry;
411
412 list_for_each_entry(entry, &map_entries, list)
413 add_sysfs_fw_map_entry(entry);
414
415 return 0;
416}
417late_initcall(firmware_memmap_init);
418
1/*
2 * linux/drivers/firmware/memmap.c
3 * Copyright (C) 2008 SUSE LINUX Products GmbH
4 * by Bernhard Walle <bernhard.walle@gmx.de>
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 v2.0 as published by
8 * the Free Software Foundation
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 */
16
17#include <linux/string.h>
18#include <linux/firmware-map.h>
19#include <linux/kernel.h>
20#include <linux/module.h>
21#include <linux/types.h>
22#include <linux/bootmem.h>
23#include <linux/slab.h>
24
25/*
26 * Data types ------------------------------------------------------------------
27 */
28
29/*
30 * Firmware map entry. Because firmware memory maps are flat and not
31 * hierarchical, it's ok to organise them in a linked list. No parent
32 * information is necessary as for the resource tree.
33 */
34struct firmware_map_entry {
35 /*
36 * start and end must be u64 rather than resource_size_t, because e820
37 * resources can lie at addresses above 4G.
38 */
39 u64 start; /* start of the memory range */
40 u64 end; /* end of the memory range (incl.) */
41 const char *type; /* type of the memory range */
42 struct list_head list; /* entry for the linked list */
43 struct kobject kobj; /* kobject for each entry */
44};
45
46/*
47 * Forward declarations --------------------------------------------------------
48 */
49static ssize_t memmap_attr_show(struct kobject *kobj,
50 struct attribute *attr, char *buf);
51static ssize_t start_show(struct firmware_map_entry *entry, char *buf);
52static ssize_t end_show(struct firmware_map_entry *entry, char *buf);
53static ssize_t type_show(struct firmware_map_entry *entry, char *buf);
54
55/*
56 * Static data -----------------------------------------------------------------
57 */
58
59struct memmap_attribute {
60 struct attribute attr;
61 ssize_t (*show)(struct firmware_map_entry *entry, char *buf);
62};
63
64static struct memmap_attribute memmap_start_attr = __ATTR_RO(start);
65static struct memmap_attribute memmap_end_attr = __ATTR_RO(end);
66static struct memmap_attribute memmap_type_attr = __ATTR_RO(type);
67
68/*
69 * These are default attributes that are added for every memmap entry.
70 */
71static struct attribute *def_attrs[] = {
72 &memmap_start_attr.attr,
73 &memmap_end_attr.attr,
74 &memmap_type_attr.attr,
75 NULL
76};
77
78static const struct sysfs_ops memmap_attr_ops = {
79 .show = memmap_attr_show,
80};
81
82static struct kobj_type memmap_ktype = {
83 .sysfs_ops = &memmap_attr_ops,
84 .default_attrs = def_attrs,
85};
86
87/*
88 * Registration functions ------------------------------------------------------
89 */
90
91/*
92 * Firmware memory map entries. No locking is needed because the
93 * firmware_map_add() and firmware_map_add_early() functions are called
94 * in firmware initialisation code in one single thread of execution.
95 */
96static LIST_HEAD(map_entries);
97
98/**
99 * firmware_map_add_entry() - Does the real work to add a firmware memmap entry.
100 * @start: Start of the memory range.
101 * @end: End of the memory range (inclusive).
102 * @type: Type of the memory range.
103 * @entry: Pre-allocated (either kmalloc() or bootmem allocator), uninitialised
104 * entry.
105 *
106 * Common implementation of firmware_map_add() and firmware_map_add_early()
107 * which expects a pre-allocated struct firmware_map_entry.
108 **/
109static int firmware_map_add_entry(u64 start, u64 end,
110 const char *type,
111 struct firmware_map_entry *entry)
112{
113 BUG_ON(start > end);
114
115 entry->start = start;
116 entry->end = end;
117 entry->type = type;
118 INIT_LIST_HEAD(&entry->list);
119 kobject_init(&entry->kobj, &memmap_ktype);
120
121 list_add_tail(&entry->list, &map_entries);
122
123 return 0;
124}
125
126/*
127 * Add memmap entry on sysfs
128 */
129static int add_sysfs_fw_map_entry(struct firmware_map_entry *entry)
130{
131 static int map_entries_nr;
132 static struct kset *mmap_kset;
133
134 if (!mmap_kset) {
135 mmap_kset = kset_create_and_add("memmap", NULL, firmware_kobj);
136 if (!mmap_kset)
137 return -ENOMEM;
138 }
139
140 entry->kobj.kset = mmap_kset;
141 if (kobject_add(&entry->kobj, NULL, "%d", map_entries_nr++))
142 kobject_put(&entry->kobj);
143
144 return 0;
145}
146
147/**
148 * firmware_map_add_hotplug() - Adds a firmware mapping entry when we do
149 * memory hotplug.
150 * @start: Start of the memory range.
151 * @end: End of the memory range (inclusive).
152 * @type: Type of the memory range.
153 *
154 * Adds a firmware mapping entry. This function is for memory hotplug, it is
155 * similar to function firmware_map_add_early(). The only difference is that
156 * it will create the syfs entry dynamically.
157 *
158 * Returns 0 on success, or -ENOMEM if no memory could be allocated.
159 **/
160int __meminit firmware_map_add_hotplug(u64 start, u64 end, const char *type)
161{
162 struct firmware_map_entry *entry;
163
164 entry = kzalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC);
165 if (!entry)
166 return -ENOMEM;
167
168 firmware_map_add_entry(start, end, type, entry);
169 /* create the memmap entry */
170 add_sysfs_fw_map_entry(entry);
171
172 return 0;
173}
174
175/**
176 * firmware_map_add_early() - Adds a firmware mapping entry.
177 * @start: Start of the memory range.
178 * @end: End of the memory range (inclusive).
179 * @type: Type of the memory range.
180 *
181 * Adds a firmware mapping entry. This function uses the bootmem allocator
182 * for memory allocation.
183 *
184 * That function must be called before late_initcall.
185 *
186 * Returns 0 on success, or -ENOMEM if no memory could be allocated.
187 **/
188int __init firmware_map_add_early(u64 start, u64 end, const char *type)
189{
190 struct firmware_map_entry *entry;
191
192 entry = alloc_bootmem(sizeof(struct firmware_map_entry));
193 if (WARN_ON(!entry))
194 return -ENOMEM;
195
196 return firmware_map_add_entry(start, end, type, entry);
197}
198
199/*
200 * Sysfs functions -------------------------------------------------------------
201 */
202
203static ssize_t start_show(struct firmware_map_entry *entry, char *buf)
204{
205 return snprintf(buf, PAGE_SIZE, "0x%llx\n",
206 (unsigned long long)entry->start);
207}
208
209static ssize_t end_show(struct firmware_map_entry *entry, char *buf)
210{
211 return snprintf(buf, PAGE_SIZE, "0x%llx\n",
212 (unsigned long long)entry->end);
213}
214
215static ssize_t type_show(struct firmware_map_entry *entry, char *buf)
216{
217 return snprintf(buf, PAGE_SIZE, "%s\n", entry->type);
218}
219
220#define to_memmap_attr(_attr) container_of(_attr, struct memmap_attribute, attr)
221#define to_memmap_entry(obj) container_of(obj, struct firmware_map_entry, kobj)
222
223static ssize_t memmap_attr_show(struct kobject *kobj,
224 struct attribute *attr, char *buf)
225{
226 struct firmware_map_entry *entry = to_memmap_entry(kobj);
227 struct memmap_attribute *memmap_attr = to_memmap_attr(attr);
228
229 return memmap_attr->show(entry, buf);
230}
231
232/*
233 * Initialises stuff and adds the entries in the map_entries list to
234 * sysfs. Important is that firmware_map_add() and firmware_map_add_early()
235 * must be called before late_initcall. That's just because that function
236 * is called as late_initcall() function, which means that if you call
237 * firmware_map_add() or firmware_map_add_early() afterwards, the entries
238 * are not added to sysfs.
239 */
240static int __init memmap_init(void)
241{
242 struct firmware_map_entry *entry;
243
244 list_for_each_entry(entry, &map_entries, list)
245 add_sysfs_fw_map_entry(entry);
246
247 return 0;
248}
249late_initcall(memmap_init);
250