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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 */
34 struct 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 */
49 static ssize_t memmap_attr_show(struct kobject *kobj,
50 struct attribute *attr, char *buf);
51 static ssize_t start_show(struct firmware_map_entry *entry, char *buf);
52 static ssize_t end_show(struct firmware_map_entry *entry, char *buf);
53 static ssize_t type_show(struct firmware_map_entry *entry, char *buf);
54
55 /*
56 * Static data -----------------------------------------------------------------
57 */
58
59 struct memmap_attribute {
60 struct attribute attr;
61 ssize_t (*show)(struct firmware_map_entry *entry, char *buf);
62 };
63
64 static struct memmap_attribute memmap_start_attr = __ATTR_RO(start);
65 static struct memmap_attribute memmap_end_attr = __ATTR_RO(end);
66 static struct memmap_attribute memmap_type_attr = __ATTR_RO(type);
67
68 /*
69 * These are default attributes that are added for every memmap entry.
70 */
71 static struct attribute *def_attrs[] = {
72 &memmap_start_attr.attr,
73 &memmap_end_attr.attr,
74 &memmap_type_attr.attr,
75 NULL
76 };
77
78 static const struct sysfs_ops memmap_attr_ops = {
79 .show = memmap_attr_show,
80 };
81
82 static 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 */
96 static 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 **/
109 static 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 */
129 static 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 **/
160 int __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 **/
188 int __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
203 static 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
209 static 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
215 static 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
223 static 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 */
240 static 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 }
249 late_initcall(memmap_init);
250