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
24 /*
25 * Data types ------------------------------------------------------------------
26 */
27
28 /*
29 * Firmware map entry. Because firmware memory maps are flat and not
30 * hierarchical, it's ok to organise them in a linked list. No parent
31 * information is necessary as for the resource tree.
32 */
33 struct firmware_map_entry {
34 /*
35 * start and end must be u64 rather than resource_size_t, because e820
36 * resources can lie at addresses above 4G.
37 */
38 u64 start; /* start of the memory range */
39 u64 end; /* end of the memory range (incl.) */
40 const char *type; /* type of the memory range */
41 struct list_head list; /* entry for the linked list */
42 struct kobject kobj; /* kobject for each entry */
43 };
44
45 /*
46 * Forward declarations --------------------------------------------------------
47 */
48 static ssize_t memmap_attr_show(struct kobject *kobj,
49 struct attribute *attr, char *buf);
50 static ssize_t start_show(struct firmware_map_entry *entry, char *buf);
51 static ssize_t end_show(struct firmware_map_entry *entry, char *buf);
52 static ssize_t type_show(struct firmware_map_entry *entry, char *buf);
53
54 /*
55 * Static data -----------------------------------------------------------------
56 */
57
58 struct memmap_attribute {
59 struct attribute attr;
60 ssize_t (*show)(struct firmware_map_entry *entry, char *buf);
61 };
62
63 static struct memmap_attribute memmap_start_attr = __ATTR_RO(start);
64 static struct memmap_attribute memmap_end_attr = __ATTR_RO(end);
65 static struct memmap_attribute memmap_type_attr = __ATTR_RO(type);
66
67 /*
68 * These are default attributes that are added for every memmap entry.
69 */
70 static struct attribute *def_attrs[] = {
71 &memmap_start_attr.attr,
72 &memmap_end_attr.attr,
73 &memmap_type_attr.attr,
74 NULL
75 };
76
77 static struct sysfs_ops memmap_attr_ops = {
78 .show = memmap_attr_show,
79 };
80
81 static struct kobj_type memmap_ktype = {
82 .sysfs_ops = &memmap_attr_ops,
83 .default_attrs = def_attrs,
84 };
85
86 /*
87 * Registration functions ------------------------------------------------------
88 */
89
90 /*
91 * Firmware memory map entries. No locking is needed because the
92 * firmware_map_add() and firmware_map_add_early() functions are called
93 * in firmware initialisation code in one single thread of execution.
94 */
95 static LIST_HEAD(map_entries);
96
97 /**
98 * firmware_map_add_entry() - Does the real work to add a firmware memmap entry.
99 * @start: Start of the memory range.
100 * @end: End of the memory range (inclusive).
101 * @type: Type of the memory range.
102 * @entry: Pre-allocated (either kmalloc() or bootmem allocator), uninitialised
103 * entry.
104 *
105 * Common implementation of firmware_map_add() and firmware_map_add_early()
106 * which expects a pre-allocated struct firmware_map_entry.
107 **/
108 static int firmware_map_add_entry(u64 start, u64 end,
109 const char *type,
110 struct firmware_map_entry *entry)
111 {
112 BUG_ON(start > end);
113
114 entry->start = start;
115 entry->end = end;
116 entry->type = type;
117 INIT_LIST_HEAD(&entry->list);
118 kobject_init(&entry->kobj, &memmap_ktype);
119
120 list_add_tail(&entry->list, &map_entries);
121
122 return 0;
123 }
124
125 /**
126 * firmware_map_add() - Adds a firmware mapping entry.
127 * @start: Start of the memory range.
128 * @end: End of the memory range (inclusive).
129 * @type: Type of the memory range.
130 *
131 * This function uses kmalloc() for memory
132 * allocation. Use firmware_map_add_early() if you want to use the bootmem
133 * allocator.
134 *
135 * That function must be called before late_initcall.
136 *
137 * Returns 0 on success, or -ENOMEM if no memory could be allocated.
138 **/
139 int firmware_map_add(u64 start, u64 end, const char *type)
140 {
141 struct firmware_map_entry *entry;
142
143 entry = kmalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC);
144 if (!entry)
145 return -ENOMEM;
146
147 return firmware_map_add_entry(start, end, type, entry);
148 }
149
150 /**
151 * firmware_map_add_early() - Adds a firmware mapping entry.
152 * @start: Start of the memory range.
153 * @end: End of the memory range (inclusive).
154 * @type: Type of the memory range.
155 *
156 * Adds a firmware mapping entry. This function uses the bootmem allocator
157 * for memory allocation. Use firmware_map_add() if you want to use kmalloc().
158 *
159 * That function must be called before late_initcall.
160 *
161 * Returns 0 on success, or -ENOMEM if no memory could be allocated.
162 **/
163 int __init firmware_map_add_early(u64 start, u64 end, const char *type)
164 {
165 struct firmware_map_entry *entry;
166
167 entry = alloc_bootmem_low(sizeof(struct firmware_map_entry));
168 if (WARN_ON(!entry))
169 return -ENOMEM;
170
171 return firmware_map_add_entry(start, end, type, entry);
172 }
173
174 /*
175 * Sysfs functions -------------------------------------------------------------
176 */
177
178 static ssize_t start_show(struct firmware_map_entry *entry, char *buf)
179 {
180 return snprintf(buf, PAGE_SIZE, "0x%llx\n",
181 (unsigned long long)entry->start);
182 }
183
184 static ssize_t end_show(struct firmware_map_entry *entry, char *buf)
185 {
186 return snprintf(buf, PAGE_SIZE, "0x%llx\n",
187 (unsigned long long)entry->end);
188 }
189
190 static ssize_t type_show(struct firmware_map_entry *entry, char *buf)
191 {
192 return snprintf(buf, PAGE_SIZE, "%s\n", entry->type);
193 }
194
195 #define to_memmap_attr(_attr) container_of(_attr, struct memmap_attribute, attr)
196 #define to_memmap_entry(obj) container_of(obj, struct firmware_map_entry, kobj)
197
198 static ssize_t memmap_attr_show(struct kobject *kobj,
199 struct attribute *attr, char *buf)
200 {
201 struct firmware_map_entry *entry = to_memmap_entry(kobj);
202 struct memmap_attribute *memmap_attr = to_memmap_attr(attr);
203
204 return memmap_attr->show(entry, buf);
205 }
206
207 /*
208 * Initialises stuff and adds the entries in the map_entries list to
209 * sysfs. Important is that firmware_map_add() and firmware_map_add_early()
210 * must be called before late_initcall. That's just because that function
211 * is called as late_initcall() function, which means that if you call
212 * firmware_map_add() or firmware_map_add_early() afterwards, the entries
213 * are not added to sysfs.
214 */
215 static int __init memmap_init(void)
216 {
217 int i = 0;
218 struct firmware_map_entry *entry;
219 struct kset *memmap_kset;
220
221 memmap_kset = kset_create_and_add("memmap", NULL, firmware_kobj);
222 if (WARN_ON(!memmap_kset))
223 return -ENOMEM;
224
225 list_for_each_entry(entry, &map_entries, list) {
226 entry->kobj.kset = memmap_kset;
227 if (kobject_add(&entry->kobj, NULL, "%d", i++))
228 kobject_put(&entry->kobj);
229 }
230
231 return 0;
232 }
233 late_initcall(memmap_init);
234
235
|
This page was automatically generated by the
LXR engine.
|