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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
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