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Bernhard Walle69ac9cd2008-06-27 13:12:54 +02001/*
2 * linux/drivers/firmware/memmap.c
3 * Copyright (C) 2008 SUSE LINUX Products GmbH
Bernhard Walle97bef7d2009-02-18 14:48:40 -08004 * by Bernhard Walle <bernhard.walle@gmx.de>
Bernhard Walle69ac9cd2008-06-27 13:12:54 +02005 *
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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090023#include <linux/slab.h>
Yasuaki Ishimatsu46c66c42013-02-22 16:32:56 -080024#include <linux/mm.h>
Bernhard Walle69ac9cd2008-06-27 13:12:54 +020025
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 {
Yinghai Lu3b0fde02009-06-16 15:31:16 -070036 /*
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.) */
Bernhard Walle69ac9cd2008-06-27 13:12:54 +020042 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
Yasuaki Ishimatsu46c66c42013-02-22 16:32:56 -080056static struct firmware_map_entry * __meminit
57firmware_map_find_entry(u64 start, u64 end, const char *type);
58
Bernhard Walle69ac9cd2008-06-27 13:12:54 +020059/*
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
Roel Kluinda2bdf92009-01-07 18:09:15 -080068static 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);
Bernhard Walle69ac9cd2008-06-27 13:12:54 +020071
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
Emese Revfy52cf25d2010-01-19 02:58:23 +010082static const struct sysfs_ops memmap_attr_ops = {
Bernhard Walle69ac9cd2008-06-27 13:12:54 +020083 .show = memmap_attr_show,
84};
85
Yasuaki Ishimatsu46c66c42013-02-22 16:32:56 -080086/* 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 */
Yasuaki Ishimatsu7a6f93b2013-04-29 15:08:39 -0700117 spin_lock(&map_entries_bootmem_lock);
118 list_add(&entry->list, &map_entries_bootmem);
119 spin_unlock(&map_entries_bootmem_lock);
Yasuaki Ishimatsu46c66c42013-02-22 16:32:56 -0800120
121 return;
122 }
123
124 kfree(entry);
125}
126
127static struct kobj_type __refdata memmap_ktype = {
128 .release = release_firmware_map_entry,
Bernhard Walle69ac9cd2008-06-27 13:12:54 +0200129 .sysfs_ops = &memmap_attr_ops,
130 .default_attrs = def_attrs,
131};
132
133/*
134 * Registration functions ------------------------------------------------------
135 */
136
Bernhard Walle69ac9cd2008-06-27 13:12:54 +0200137/**
Bernhard Walle31bad922008-08-12 15:09:14 -0700138 * firmware_map_add_entry() - Does the real work to add a firmware memmap entry.
Bernhard Walle69ac9cd2008-06-27 13:12:54 +0200139 * @start: Start of the memory range.
Yasuaki Ishimatsu4ed940d2012-07-30 14:41:13 -0700140 * @end: End of the memory range (exclusive).
Bernhard Walle69ac9cd2008-06-27 13:12:54 +0200141 * @type: Type of the memory range.
142 * @entry: Pre-allocated (either kmalloc() or bootmem allocator), uninitialised
143 * entry.
Bernhard Walle31bad922008-08-12 15:09:14 -0700144 *
145 * Common implementation of firmware_map_add() and firmware_map_add_early()
146 * which expects a pre-allocated struct firmware_map_entry.
147 **/
Yinghai Lu3b0fde02009-06-16 15:31:16 -0700148static int firmware_map_add_entry(u64 start, u64 end,
Bernhard Walle69ac9cd2008-06-27 13:12:54 +0200149 const char *type,
150 struct firmware_map_entry *entry)
151{
152 BUG_ON(start > end);
153
154 entry->start = start;
Yasuaki Ishimatsu4ed940d2012-07-30 14:41:13 -0700155 entry->end = end - 1;
Bernhard Walle69ac9cd2008-06-27 13:12:54 +0200156 entry->type = type;
157 INIT_LIST_HEAD(&entry->list);
158 kobject_init(&entry->kobj, &memmap_ktype);
159
Yasuaki Ishimatsu46c66c42013-02-22 16:32:56 -0800160 spin_lock(&map_entries_lock);
Bernhard Walle69ac9cd2008-06-27 13:12:54 +0200161 list_add_tail(&entry->list, &map_entries);
Yasuaki Ishimatsu46c66c42013-02-22 16:32:56 -0800162 spin_unlock(&map_entries_lock);
Bernhard Walle69ac9cd2008-06-27 13:12:54 +0200163
164 return 0;
165}
166
Yasuaki Ishimatsu46c66c42013-02-22 16:32:56 -0800167/**
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
akpm@linux-foundation.orgd96ae532010-03-05 13:41:58 -0800179/*
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
Yasuaki Ishimatsu46c66c42013-02-22 16:32:56 -0800200/*
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
Bernhard Walle31bad922008-08-12 15:09:14 -0700272/**
akpm@linux-foundation.orgd96ae532010-03-05 13:41:58 -0800273 * firmware_map_add_hotplug() - Adds a firmware mapping entry when we do
274 * memory hotplug.
Bernhard Walle31bad922008-08-12 15:09:14 -0700275 * @start: Start of the memory range.
Yasuaki Ishimatsu4ed940d2012-07-30 14:41:13 -0700276 * @end: End of the memory range (exclusive)
Bernhard Walle31bad922008-08-12 15:09:14 -0700277 * @type: Type of the memory range.
278 *
akpm@linux-foundation.orgd96ae532010-03-05 13:41:58 -0800279 * 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.
Bernhard Walle31bad922008-08-12 15:09:14 -0700282 *
283 * Returns 0 on success, or -ENOMEM if no memory could be allocated.
284 **/
akpm@linux-foundation.orgd96ae532010-03-05 13:41:58 -0800285int __meminit firmware_map_add_hotplug(u64 start, u64 end, const char *type)
Bernhard Walle69ac9cd2008-06-27 13:12:54 +0200286{
287 struct firmware_map_entry *entry;
288
Yasuaki Ishimatsu46c66c42013-02-22 16:32:56 -0800289 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 }
Bernhard Walle69ac9cd2008-06-27 13:12:54 +0200302
akpm@linux-foundation.orgd96ae532010-03-05 13:41:58 -0800303 firmware_map_add_entry(start, end, type, entry);
304 /* create the memmap entry */
305 add_sysfs_fw_map_entry(entry);
306
307 return 0;
Bernhard Walle69ac9cd2008-06-27 13:12:54 +0200308}
309
Bernhard Walle31bad922008-08-12 15:09:14 -0700310/**
311 * firmware_map_add_early() - Adds a firmware mapping entry.
312 * @start: Start of the memory range.
Yasuaki Ishimatsu4ed940d2012-07-30 14:41:13 -0700313 * @end: End of the memory range.
Bernhard Walle31bad922008-08-12 15:09:14 -0700314 * @type: Type of the memory range.
315 *
316 * Adds a firmware mapping entry. This function uses the bootmem allocator
akpm@linux-foundation.orgd96ae532010-03-05 13:41:58 -0800317 * for memory allocation.
Bernhard Walle31bad922008-08-12 15:09:14 -0700318 *
319 * That function must be called before late_initcall.
320 *
321 * Returns 0 on success, or -ENOMEM if no memory could be allocated.
322 **/
Yinghai Lu3b0fde02009-06-16 15:31:16 -0700323int __init firmware_map_add_early(u64 start, u64 end, const char *type)
Bernhard Walle69ac9cd2008-06-27 13:12:54 +0200324{
325 struct firmware_map_entry *entry;
326
Jan Beulich3c1596e2009-09-21 17:03:06 -0700327 entry = alloc_bootmem(sizeof(struct firmware_map_entry));
Bernhard Walle31bad922008-08-12 15:09:14 -0700328 if (WARN_ON(!entry))
Bernhard Walle69ac9cd2008-06-27 13:12:54 +0200329 return -ENOMEM;
330
331 return firmware_map_add_entry(start, end, type, entry);
332}
333
Yasuaki Ishimatsu46c66c42013-02-22 16:32:56 -0800334/**
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
Bernhard Walle69ac9cd2008-06-27 13:12:54 +0200364/*
365 * Sysfs functions -------------------------------------------------------------
366 */
367
368static ssize_t start_show(struct firmware_map_entry *entry, char *buf)
369{
Randy Dunlap78681ac2008-07-26 15:22:28 -0700370 return snprintf(buf, PAGE_SIZE, "0x%llx\n",
371 (unsigned long long)entry->start);
Bernhard Walle69ac9cd2008-06-27 13:12:54 +0200372}
373
374static ssize_t end_show(struct firmware_map_entry *entry, char *buf)
375{
Randy Dunlap78681ac2008-07-26 15:22:28 -0700376 return snprintf(buf, PAGE_SIZE, "0x%llx\n",
377 (unsigned long long)entry->end);
Bernhard Walle69ac9cd2008-06-27 13:12:54 +0200378}
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
Yasuaki Ishimatsu46c66c42013-02-22 16:32:56 -0800385static inline struct memmap_attribute *to_memmap_attr(struct attribute *attr)
386{
387 return container_of(attr, struct memmap_attribute, attr);
388}
Bernhard Walle69ac9cd2008-06-27 13:12:54 +0200389
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()
Bernhard Walle31bad922008-08-12 15:09:14 -0700402 * 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.
Bernhard Walle69ac9cd2008-06-27 13:12:54 +0200406 */
Fengguang Wubac71692012-10-19 13:56:55 -0700407static int __init firmware_memmap_init(void)
Bernhard Walle69ac9cd2008-06-27 13:12:54 +0200408{
Bernhard Walle69ac9cd2008-06-27 13:12:54 +0200409 struct firmware_map_entry *entry;
Bernhard Walle69ac9cd2008-06-27 13:12:54 +0200410
akpm@linux-foundation.orgd96ae532010-03-05 13:41:58 -0800411 list_for_each_entry(entry, &map_entries, list)
412 add_sysfs_fw_map_entry(entry);
Bernhard Walle69ac9cd2008-06-27 13:12:54 +0200413
414 return 0;
415}
Fengguang Wubac71692012-10-19 13:56:55 -0700416late_initcall(firmware_memmap_init);
Bernhard Walle69ac9cd2008-06-27 13:12:54 +0200417