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v6.8
  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};
 72ATTRIBUTE_GROUPS(def);
 73
 74static const struct sysfs_ops memmap_attr_ops = {
 75	.show = memmap_attr_show,
 76};
 77
 78/* Firmware memory map entries. */
 79static LIST_HEAD(map_entries);
 80static DEFINE_SPINLOCK(map_entries_lock);
 81
 82/*
 83 * For memory hotplug, there is no way to free memory map entries allocated
 84 * by boot mem after the system is up. So when we hot-remove memory whose
 85 * map entry is allocated by bootmem, we need to remember the storage and
 86 * reuse it when the memory is hot-added again.
 87 */
 88static LIST_HEAD(map_entries_bootmem);
 89static DEFINE_SPINLOCK(map_entries_bootmem_lock);
 90
 91
 92static inline struct firmware_map_entry *
 93to_memmap_entry(struct kobject *kobj)
 94{
 95	return container_of(kobj, struct firmware_map_entry, kobj);
 96}
 97
 98static void __meminit release_firmware_map_entry(struct kobject *kobj)
 99{
100	struct firmware_map_entry *entry = to_memmap_entry(kobj);
101
102	if (PageReserved(virt_to_page(entry))) {
103		/*
104		 * Remember the storage allocated by bootmem, and reuse it when
105		 * the memory is hot-added again. The entry will be added to
106		 * map_entries_bootmem here, and deleted from &map_entries in
107		 * firmware_map_remove_entry().
108		 */
109		spin_lock(&map_entries_bootmem_lock);
110		list_add(&entry->list, &map_entries_bootmem);
111		spin_unlock(&map_entries_bootmem_lock);
112
113		return;
114	}
115
116	kfree(entry);
117}
118
119static struct kobj_type __refdata memmap_ktype = {
120	.release	= release_firmware_map_entry,
121	.sysfs_ops	= &memmap_attr_ops,
122	.default_groups	= def_groups,
123};
124
125/*
126 * Registration functions ------------------------------------------------------
127 */
128
129/**
130 * firmware_map_add_entry() - Does the real work to add a firmware memmap entry.
131 * @start: Start of the memory range.
132 * @end:   End of the memory range (exclusive).
133 * @type:  Type of the memory range.
134 * @entry: Pre-allocated (either kmalloc() or bootmem allocator), uninitialised
135 *         entry.
136 *
137 * Common implementation of firmware_map_add() and firmware_map_add_early()
138 * which expects a pre-allocated struct firmware_map_entry.
139 *
140 * Return: 0 always
141 */
142static int firmware_map_add_entry(u64 start, u64 end,
143				  const char *type,
144				  struct firmware_map_entry *entry)
145{
146	BUG_ON(start > end);
147
148	entry->start = start;
149	entry->end = end - 1;
150	entry->type = type;
151	INIT_LIST_HEAD(&entry->list);
152	kobject_init(&entry->kobj, &memmap_ktype);
153
154	spin_lock(&map_entries_lock);
155	list_add_tail(&entry->list, &map_entries);
156	spin_unlock(&map_entries_lock);
157
158	return 0;
159}
160
161/**
162 * firmware_map_remove_entry() - Does the real work to remove a firmware
163 * memmap entry.
164 * @entry: removed entry.
165 *
166 * The caller must hold map_entries_lock, and release it properly.
167 */
168static inline void firmware_map_remove_entry(struct firmware_map_entry *entry)
169{
170	list_del(&entry->list);
171}
172
173/*
174 * Add memmap entry on sysfs
175 */
176static int add_sysfs_fw_map_entry(struct firmware_map_entry *entry)
177{
178	static int map_entries_nr;
179	static struct kset *mmap_kset;
180
181	if (entry->kobj.state_in_sysfs)
182		return -EEXIST;
183
184	if (!mmap_kset) {
185		mmap_kset = kset_create_and_add("memmap", NULL, firmware_kobj);
186		if (!mmap_kset)
187			return -ENOMEM;
188	}
189
190	entry->kobj.kset = mmap_kset;
191	if (kobject_add(&entry->kobj, NULL, "%d", map_entries_nr++))
192		kobject_put(&entry->kobj);
193
194	return 0;
195}
196
197/*
198 * Remove memmap entry on sysfs
199 */
200static inline void remove_sysfs_fw_map_entry(struct firmware_map_entry *entry)
201{
202	kobject_put(&entry->kobj);
203}
204
205/**
206 * firmware_map_find_entry_in_list() - Search memmap entry in a given list.
207 * @start: Start of the memory range.
208 * @end:   End of the memory range (exclusive).
209 * @type:  Type of the memory range.
210 * @list:  In which to find the entry.
211 *
212 * This function is to find the memmap entey of a given memory range in a
213 * given list. The caller must hold map_entries_lock, and must not release
214 * the lock until the processing of the returned entry has completed.
215 *
216 * Return: Pointer to the entry to be found on success, or NULL on failure.
217 */
218static struct firmware_map_entry * __meminit
219firmware_map_find_entry_in_list(u64 start, u64 end, const char *type,
220				struct list_head *list)
221{
222	struct firmware_map_entry *entry;
223
224	list_for_each_entry(entry, list, list)
225		if ((entry->start == start) && (entry->end == end) &&
226		    (!strcmp(entry->type, type))) {
227			return entry;
228		}
229
230	return NULL;
231}
232
233/**
234 * firmware_map_find_entry() - Search memmap entry in map_entries.
235 * @start: Start of the memory range.
236 * @end:   End of the memory range (exclusive).
237 * @type:  Type of the memory range.
238 *
239 * This function is to find the memmap entey of a given memory range.
240 * The caller must hold map_entries_lock, and must not release the lock
241 * until the processing of the returned entry has completed.
242 *
243 * Return: Pointer to the entry to be found on success, or NULL on failure.
244 */
245static struct firmware_map_entry * __meminit
246firmware_map_find_entry(u64 start, u64 end, const char *type)
247{
248	return firmware_map_find_entry_in_list(start, end, type, &map_entries);
249}
250
251/**
252 * firmware_map_find_entry_bootmem() - Search memmap entry in map_entries_bootmem.
253 * @start: Start of the memory range.
254 * @end:   End of the memory range (exclusive).
255 * @type:  Type of the memory range.
256 *
257 * This function is similar to firmware_map_find_entry except that it find the
258 * given entry in map_entries_bootmem.
259 *
260 * Return: Pointer to the entry to be found on success, or NULL on failure.
261 */
262static struct firmware_map_entry * __meminit
263firmware_map_find_entry_bootmem(u64 start, u64 end, const char *type)
264{
265	return firmware_map_find_entry_in_list(start, end, type,
266					       &map_entries_bootmem);
267}
268
269/**
270 * firmware_map_add_hotplug() - Adds a firmware mapping entry when we do
271 * memory hotplug.
272 * @start: Start of the memory range.
273 * @end:   End of the memory range (exclusive)
274 * @type:  Type of the memory range.
275 *
276 * Adds a firmware mapping entry. This function is for memory hotplug, it is
277 * similar to function firmware_map_add_early(). The only difference is that
278 * it will create the syfs entry dynamically.
279 *
280 * Return: 0 on success, or -ENOMEM if no memory could be allocated.
281 */
282int __meminit firmware_map_add_hotplug(u64 start, u64 end, const char *type)
283{
284	struct firmware_map_entry *entry;
285
286	entry = firmware_map_find_entry(start, end - 1, type);
287	if (entry)
288		return 0;
289
290	entry = firmware_map_find_entry_bootmem(start, end - 1, type);
291	if (!entry) {
292		entry = kzalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC);
293		if (!entry)
294			return -ENOMEM;
295	} else {
296		/* Reuse storage allocated by bootmem. */
297		spin_lock(&map_entries_bootmem_lock);
298		list_del(&entry->list);
299		spin_unlock(&map_entries_bootmem_lock);
300
301		memset(entry, 0, sizeof(*entry));
302	}
303
304	firmware_map_add_entry(start, end, type, entry);
305	/* create the memmap entry */
306	add_sysfs_fw_map_entry(entry);
307
308	return 0;
309}
310
311/**
312 * firmware_map_add_early() - Adds a firmware mapping entry.
313 * @start: Start of the memory range.
314 * @end:   End of the memory range.
315 * @type:  Type of the memory range.
316 *
317 * Adds a firmware mapping entry. This function uses the bootmem allocator
318 * for memory allocation.
319 *
320 * That function must be called before late_initcall.
321 *
322 * Return: 0 on success, or -ENOMEM if no memory could be allocated.
323 */
324int __init firmware_map_add_early(u64 start, u64 end, const char *type)
325{
326	struct firmware_map_entry *entry;
327
328	entry = memblock_alloc(sizeof(struct firmware_map_entry),
329			       SMP_CACHE_BYTES);
330	if (WARN_ON(!entry))
331		return -ENOMEM;
332
333	return firmware_map_add_entry(start, end, type, entry);
334}
335
336/**
337 * firmware_map_remove() - remove a firmware mapping entry
338 * @start: Start of the memory range.
339 * @end:   End of the memory range.
340 * @type:  Type of the memory range.
341 *
342 * removes a firmware mapping entry.
343 *
344 * Return: 0 on success, or -EINVAL if no entry.
345 */
346int __meminit firmware_map_remove(u64 start, u64 end, const char *type)
347{
348	struct firmware_map_entry *entry;
349
350	spin_lock(&map_entries_lock);
351	entry = firmware_map_find_entry(start, end - 1, type);
352	if (!entry) {
353		spin_unlock(&map_entries_lock);
354		return -EINVAL;
355	}
356
357	firmware_map_remove_entry(entry);
358	spin_unlock(&map_entries_lock);
359
360	/* remove the memmap entry */
361	remove_sysfs_fw_map_entry(entry);
362
363	return 0;
364}
365
366/*
367 * Sysfs functions -------------------------------------------------------------
368 */
369
370static ssize_t start_show(struct firmware_map_entry *entry, char *buf)
371{
372	return snprintf(buf, PAGE_SIZE, "0x%llx\n",
373		(unsigned long long)entry->start);
374}
375
376static ssize_t end_show(struct firmware_map_entry *entry, char *buf)
377{
378	return snprintf(buf, PAGE_SIZE, "0x%llx\n",
379		(unsigned long long)entry->end);
380}
381
382static ssize_t type_show(struct firmware_map_entry *entry, char *buf)
383{
384	return snprintf(buf, PAGE_SIZE, "%s\n", entry->type);
385}
386
387static inline struct memmap_attribute *to_memmap_attr(struct attribute *attr)
388{
389	return container_of(attr, struct memmap_attribute, attr);
390}
391
392static ssize_t memmap_attr_show(struct kobject *kobj,
393				struct attribute *attr, char *buf)
394{
395	struct firmware_map_entry *entry = to_memmap_entry(kobj);
396	struct memmap_attribute *memmap_attr = to_memmap_attr(attr);
397
398	return memmap_attr->show(entry, buf);
399}
400
401/*
402 * Initialises stuff and adds the entries in the map_entries list to
403 * sysfs. Important is that firmware_map_add() and firmware_map_add_early()
404 * must be called before late_initcall. That's just because that function
405 * is called as late_initcall() function, which means that if you call
406 * firmware_map_add() or firmware_map_add_early() afterwards, the entries
407 * are not added to sysfs.
408 */
409static int __init firmware_memmap_init(void)
410{
411	struct firmware_map_entry *entry;
412
413	list_for_each_entry(entry, &map_entries, list)
414		add_sysfs_fw_map_entry(entry);
415
416	return 0;
417}
418late_initcall(firmware_memmap_init);
419
v3.15
 
  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#include <linux/mm.h>
 25
 26/*
 27 * Data types ------------------------------------------------------------------
 28 */
 29
 30/*
 31 * Firmware map entry. Because firmware memory maps are flat and not
 32 * hierarchical, it's ok to organise them in a linked list. No parent
 33 * information is necessary as for the resource tree.
 34 */
 35struct firmware_map_entry {
 36	/*
 37	 * start and end must be u64 rather than resource_size_t, because e820
 38	 * resources can lie at addresses above 4G.
 39	 */
 40	u64			start;	/* start of the memory range */
 41	u64			end;	/* end of the memory range (incl.) */
 42	const char		*type;	/* type of the memory range */
 43	struct list_head	list;	/* entry for the linked list */
 44	struct kobject		kobj;   /* kobject for each entry */
 45};
 46
 47/*
 48 * Forward declarations --------------------------------------------------------
 49 */
 50static ssize_t memmap_attr_show(struct kobject *kobj,
 51				struct attribute *attr, char *buf);
 52static ssize_t start_show(struct firmware_map_entry *entry, char *buf);
 53static ssize_t end_show(struct firmware_map_entry *entry, char *buf);
 54static ssize_t type_show(struct firmware_map_entry *entry, char *buf);
 55
 56static struct firmware_map_entry * __meminit
 57firmware_map_find_entry(u64 start, u64 end, const char *type);
 58
 59/*
 60 * Static data -----------------------------------------------------------------
 61 */
 62
 63struct memmap_attribute {
 64	struct attribute attr;
 65	ssize_t (*show)(struct firmware_map_entry *entry, char *buf);
 66};
 67
 68static struct memmap_attribute memmap_start_attr = __ATTR_RO(start);
 69static struct memmap_attribute memmap_end_attr   = __ATTR_RO(end);
 70static struct memmap_attribute memmap_type_attr  = __ATTR_RO(type);
 71
 72/*
 73 * These are default attributes that are added for every memmap entry.
 74 */
 75static struct attribute *def_attrs[] = {
 76	&memmap_start_attr.attr,
 77	&memmap_end_attr.attr,
 78	&memmap_type_attr.attr,
 79	NULL
 80};
 
 81
 82static const struct sysfs_ops memmap_attr_ops = {
 83	.show = memmap_attr_show,
 84};
 85
 86/* Firmware memory map entries. */
 87static LIST_HEAD(map_entries);
 88static DEFINE_SPINLOCK(map_entries_lock);
 89
 90/*
 91 * For memory hotplug, there is no way to free memory map entries allocated
 92 * by boot mem after the system is up. So when we hot-remove memory whose
 93 * map entry is allocated by bootmem, we need to remember the storage and
 94 * reuse it when the memory is hot-added again.
 95 */
 96static LIST_HEAD(map_entries_bootmem);
 97static DEFINE_SPINLOCK(map_entries_bootmem_lock);
 98
 99
100static inline struct firmware_map_entry *
101to_memmap_entry(struct kobject *kobj)
102{
103	return container_of(kobj, struct firmware_map_entry, kobj);
104}
105
106static void __meminit release_firmware_map_entry(struct kobject *kobj)
107{
108	struct firmware_map_entry *entry = to_memmap_entry(kobj);
109
110	if (PageReserved(virt_to_page(entry))) {
111		/*
112		 * Remember the storage allocated by bootmem, and reuse it when
113		 * the memory is hot-added again. The entry will be added to
114		 * map_entries_bootmem here, and deleted from &map_entries in
115		 * firmware_map_remove_entry().
116		 */
117		spin_lock(&map_entries_bootmem_lock);
118		list_add(&entry->list, &map_entries_bootmem);
119		spin_unlock(&map_entries_bootmem_lock);
120
121		return;
122	}
123
124	kfree(entry);
125}
126
127static struct kobj_type __refdata memmap_ktype = {
128	.release	= release_firmware_map_entry,
129	.sysfs_ops	= &memmap_attr_ops,
130	.default_attrs	= def_attrs,
131};
132
133/*
134 * Registration functions ------------------------------------------------------
135 */
136
137/**
138 * firmware_map_add_entry() - Does the real work to add a firmware memmap entry.
139 * @start: Start of the memory range.
140 * @end:   End of the memory range (exclusive).
141 * @type:  Type of the memory range.
142 * @entry: Pre-allocated (either kmalloc() or bootmem allocator), uninitialised
143 *         entry.
144 *
145 * Common implementation of firmware_map_add() and firmware_map_add_early()
146 * which expects a pre-allocated struct firmware_map_entry.
147 **/
 
 
148static int firmware_map_add_entry(u64 start, u64 end,
149				  const char *type,
150				  struct firmware_map_entry *entry)
151{
152	BUG_ON(start > end);
153
154	entry->start = start;
155	entry->end = end - 1;
156	entry->type = type;
157	INIT_LIST_HEAD(&entry->list);
158	kobject_init(&entry->kobj, &memmap_ktype);
159
160	spin_lock(&map_entries_lock);
161	list_add_tail(&entry->list, &map_entries);
162	spin_unlock(&map_entries_lock);
163
164	return 0;
165}
166
167/**
168 * firmware_map_remove_entry() - Does the real work to remove a firmware
169 * memmap entry.
170 * @entry: removed entry.
171 *
172 * The caller must hold map_entries_lock, and release it properly.
173 **/
174static inline void firmware_map_remove_entry(struct firmware_map_entry *entry)
175{
176	list_del(&entry->list);
177}
178
179/*
180 * Add memmap entry on sysfs
181 */
182static int add_sysfs_fw_map_entry(struct firmware_map_entry *entry)
183{
184	static int map_entries_nr;
185	static struct kset *mmap_kset;
186
 
 
 
187	if (!mmap_kset) {
188		mmap_kset = kset_create_and_add("memmap", NULL, firmware_kobj);
189		if (!mmap_kset)
190			return -ENOMEM;
191	}
192
193	entry->kobj.kset = mmap_kset;
194	if (kobject_add(&entry->kobj, NULL, "%d", map_entries_nr++))
195		kobject_put(&entry->kobj);
196
197	return 0;
198}
199
200/*
201 * Remove memmap entry on sysfs
202 */
203static inline void remove_sysfs_fw_map_entry(struct firmware_map_entry *entry)
204{
205	kobject_put(&entry->kobj);
206}
207
208/*
209 * firmware_map_find_entry_in_list() - Search memmap entry in a given list.
210 * @start: Start of the memory range.
211 * @end:   End of the memory range (exclusive).
212 * @type:  Type of the memory range.
213 * @list:  In which to find the entry.
214 *
215 * This function is to find the memmap entey of a given memory range in a
216 * given list. The caller must hold map_entries_lock, and must not release
217 * the lock until the processing of the returned entry has completed.
218 *
219 * Return: Pointer to the entry to be found on success, or NULL on failure.
220 */
221static struct firmware_map_entry * __meminit
222firmware_map_find_entry_in_list(u64 start, u64 end, const char *type,
223				struct list_head *list)
224{
225	struct firmware_map_entry *entry;
226
227	list_for_each_entry(entry, list, list)
228		if ((entry->start == start) && (entry->end == end) &&
229		    (!strcmp(entry->type, type))) {
230			return entry;
231		}
232
233	return NULL;
234}
235
236/*
237 * firmware_map_find_entry() - Search memmap entry in map_entries.
238 * @start: Start of the memory range.
239 * @end:   End of the memory range (exclusive).
240 * @type:  Type of the memory range.
241 *
242 * This function is to find the memmap entey of a given memory range.
243 * The caller must hold map_entries_lock, and must not release the lock
244 * until the processing of the returned entry has completed.
245 *
246 * Return: Pointer to the entry to be found on success, or NULL on failure.
247 */
248static struct firmware_map_entry * __meminit
249firmware_map_find_entry(u64 start, u64 end, const char *type)
250{
251	return firmware_map_find_entry_in_list(start, end, type, &map_entries);
252}
253
254/*
255 * firmware_map_find_entry_bootmem() - Search memmap entry in map_entries_bootmem.
256 * @start: Start of the memory range.
257 * @end:   End of the memory range (exclusive).
258 * @type:  Type of the memory range.
259 *
260 * This function is similar to firmware_map_find_entry except that it find the
261 * given entry in map_entries_bootmem.
262 *
263 * Return: Pointer to the entry to be found on success, or NULL on failure.
264 */
265static struct firmware_map_entry * __meminit
266firmware_map_find_entry_bootmem(u64 start, u64 end, const char *type)
267{
268	return firmware_map_find_entry_in_list(start, end, type,
269					       &map_entries_bootmem);
270}
271
272/**
273 * firmware_map_add_hotplug() - Adds a firmware mapping entry when we do
274 * memory hotplug.
275 * @start: Start of the memory range.
276 * @end:   End of the memory range (exclusive)
277 * @type:  Type of the memory range.
278 *
279 * Adds a firmware mapping entry. This function is for memory hotplug, it is
280 * similar to function firmware_map_add_early(). The only difference is that
281 * it will create the syfs entry dynamically.
282 *
283 * Returns 0 on success, or -ENOMEM if no memory could be allocated.
284 **/
285int __meminit firmware_map_add_hotplug(u64 start, u64 end, const char *type)
286{
287	struct firmware_map_entry *entry;
288
289	entry = firmware_map_find_entry_bootmem(start, end, 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 * Returns 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_virt_alloc(sizeof(struct firmware_map_entry), 0);
 
328	if (WARN_ON(!entry))
329		return -ENOMEM;
330
331	return firmware_map_add_entry(start, end, type, entry);
332}
333
334/**
335 * firmware_map_remove() - remove a firmware mapping entry
336 * @start: Start of the memory range.
337 * @end:   End of the memory range.
338 * @type:  Type of the memory range.
339 *
340 * removes a firmware mapping entry.
341 *
342 * Returns 0 on success, or -EINVAL if no entry.
343 **/
344int __meminit firmware_map_remove(u64 start, u64 end, const char *type)
345{
346	struct firmware_map_entry *entry;
347
348	spin_lock(&map_entries_lock);
349	entry = firmware_map_find_entry(start, end - 1, type);
350	if (!entry) {
351		spin_unlock(&map_entries_lock);
352		return -EINVAL;
353	}
354
355	firmware_map_remove_entry(entry);
356	spin_unlock(&map_entries_lock);
357
358	/* remove the memmap entry */
359	remove_sysfs_fw_map_entry(entry);
360
361	return 0;
362}
363
364/*
365 * Sysfs functions -------------------------------------------------------------
366 */
367
368static ssize_t start_show(struct firmware_map_entry *entry, char *buf)
369{
370	return snprintf(buf, PAGE_SIZE, "0x%llx\n",
371		(unsigned long long)entry->start);
372}
373
374static ssize_t end_show(struct firmware_map_entry *entry, char *buf)
375{
376	return snprintf(buf, PAGE_SIZE, "0x%llx\n",
377		(unsigned long long)entry->end);
378}
379
380static ssize_t type_show(struct firmware_map_entry *entry, char *buf)
381{
382	return snprintf(buf, PAGE_SIZE, "%s\n", entry->type);
383}
384
385static inline struct memmap_attribute *to_memmap_attr(struct attribute *attr)
386{
387	return container_of(attr, struct memmap_attribute, attr);
388}
389
390static ssize_t memmap_attr_show(struct kobject *kobj,
391				struct attribute *attr, char *buf)
392{
393	struct firmware_map_entry *entry = to_memmap_entry(kobj);
394	struct memmap_attribute *memmap_attr = to_memmap_attr(attr);
395
396	return memmap_attr->show(entry, buf);
397}
398
399/*
400 * Initialises stuff and adds the entries in the map_entries list to
401 * sysfs. Important is that firmware_map_add() and firmware_map_add_early()
402 * must be called before late_initcall. That's just because that function
403 * is called as late_initcall() function, which means that if you call
404 * firmware_map_add() or firmware_map_add_early() afterwards, the entries
405 * are not added to sysfs.
406 */
407static int __init firmware_memmap_init(void)
408{
409	struct firmware_map_entry *entry;
410
411	list_for_each_entry(entry, &map_entries, list)
412		add_sysfs_fw_map_entry(entry);
413
414	return 0;
415}
416late_initcall(firmware_memmap_init);
417