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1 | /* |
2 | * linux/drivers/firmware/memmap.c | |
3 | * Copyright (C) 2008 SUSE LINUX Products GmbH | |
4 | * by Bernhard Walle <bwalle@suse.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 | resource_size_t start; /* start of the memory range */ | |
35 | resource_size_t end; /* end of the memory range (incl.) */ | |
36 | const char *type; /* type of the memory range */ | |
37 | struct list_head list; /* entry for the linked list */ | |
38 | struct kobject kobj; /* kobject for each entry */ | |
39 | }; | |
40 | ||
41 | /* | |
42 | * Forward declarations -------------------------------------------------------- | |
43 | */ | |
44 | static ssize_t memmap_attr_show(struct kobject *kobj, | |
45 | struct attribute *attr, char *buf); | |
46 | static ssize_t start_show(struct firmware_map_entry *entry, char *buf); | |
47 | static ssize_t end_show(struct firmware_map_entry *entry, char *buf); | |
48 | static ssize_t type_show(struct firmware_map_entry *entry, char *buf); | |
49 | ||
50 | /* | |
51 | * Static data ----------------------------------------------------------------- | |
52 | */ | |
53 | ||
54 | struct memmap_attribute { | |
55 | struct attribute attr; | |
56 | ssize_t (*show)(struct firmware_map_entry *entry, char *buf); | |
57 | }; | |
58 | ||
59 | struct memmap_attribute memmap_start_attr = __ATTR_RO(start); | |
60 | struct memmap_attribute memmap_end_attr = __ATTR_RO(end); | |
61 | struct memmap_attribute memmap_type_attr = __ATTR_RO(type); | |
62 | ||
63 | /* | |
64 | * These are default attributes that are added for every memmap entry. | |
65 | */ | |
66 | static struct attribute *def_attrs[] = { | |
67 | &memmap_start_attr.attr, | |
68 | &memmap_end_attr.attr, | |
69 | &memmap_type_attr.attr, | |
70 | NULL | |
71 | }; | |
72 | ||
73 | static struct sysfs_ops memmap_attr_ops = { | |
74 | .show = memmap_attr_show, | |
75 | }; | |
76 | ||
77 | static struct kobj_type memmap_ktype = { | |
78 | .sysfs_ops = &memmap_attr_ops, | |
79 | .default_attrs = def_attrs, | |
80 | }; | |
81 | ||
82 | /* | |
83 | * Registration functions ------------------------------------------------------ | |
84 | */ | |
85 | ||
86 | /* | |
31bad924 BW |
87 | * Firmware memory map entries. No locking is needed because the |
88 | * firmware_map_add() and firmware_map_add_early() functions are called | |
89 | * in firmware initialisation code in one single thread of execution. | |
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90 | */ |
91 | static LIST_HEAD(map_entries); | |
92 | ||
93 | /** | |
31bad924 | 94 | * firmware_map_add_entry() - Does the real work to add a firmware memmap entry. |
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95 | * @start: Start of the memory range. |
96 | * @end: End of the memory range (inclusive). | |
97 | * @type: Type of the memory range. | |
98 | * @entry: Pre-allocated (either kmalloc() or bootmem allocator), uninitialised | |
99 | * entry. | |
31bad924 BW |
100 | * |
101 | * Common implementation of firmware_map_add() and firmware_map_add_early() | |
102 | * which expects a pre-allocated struct firmware_map_entry. | |
103 | **/ | |
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104 | static int firmware_map_add_entry(resource_size_t start, resource_size_t end, |
105 | const char *type, | |
106 | struct firmware_map_entry *entry) | |
107 | { | |
108 | BUG_ON(start > end); | |
109 | ||
110 | entry->start = start; | |
111 | entry->end = end; | |
112 | entry->type = type; | |
113 | INIT_LIST_HEAD(&entry->list); | |
114 | kobject_init(&entry->kobj, &memmap_ktype); | |
115 | ||
116 | list_add_tail(&entry->list, &map_entries); | |
117 | ||
118 | return 0; | |
119 | } | |
120 | ||
31bad924 BW |
121 | /** |
122 | * firmware_map_add() - Adds a firmware mapping entry. | |
123 | * @start: Start of the memory range. | |
124 | * @end: End of the memory range (inclusive). | |
125 | * @type: Type of the memory range. | |
126 | * | |
127 | * This function uses kmalloc() for memory | |
128 | * allocation. Use firmware_map_add_early() if you want to use the bootmem | |
129 | * allocator. | |
130 | * | |
131 | * That function must be called before late_initcall. | |
132 | * | |
133 | * Returns 0 on success, or -ENOMEM if no memory could be allocated. | |
134 | **/ | |
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135 | int firmware_map_add(resource_size_t start, resource_size_t end, |
136 | const char *type) | |
137 | { | |
138 | struct firmware_map_entry *entry; | |
139 | ||
140 | entry = kmalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC); | |
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141 | if (!entry) |
142 | return -ENOMEM; | |
143 | ||
144 | return firmware_map_add_entry(start, end, type, entry); | |
145 | } | |
146 | ||
31bad924 BW |
147 | /** |
148 | * firmware_map_add_early() - Adds a firmware mapping entry. | |
149 | * @start: Start of the memory range. | |
150 | * @end: End of the memory range (inclusive). | |
151 | * @type: Type of the memory range. | |
152 | * | |
153 | * Adds a firmware mapping entry. This function uses the bootmem allocator | |
154 | * for memory allocation. Use firmware_map_add() if you want to use kmalloc(). | |
155 | * | |
156 | * That function must be called before late_initcall. | |
157 | * | |
158 | * Returns 0 on success, or -ENOMEM if no memory could be allocated. | |
159 | **/ | |
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160 | int __init firmware_map_add_early(resource_size_t start, resource_size_t end, |
161 | const char *type) | |
162 | { | |
163 | struct firmware_map_entry *entry; | |
164 | ||
165 | entry = alloc_bootmem_low(sizeof(struct firmware_map_entry)); | |
31bad924 | 166 | if (WARN_ON(!entry)) |
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167 | return -ENOMEM; |
168 | ||
169 | return firmware_map_add_entry(start, end, type, entry); | |
170 | } | |
171 | ||
172 | /* | |
173 | * Sysfs functions ------------------------------------------------------------- | |
174 | */ | |
175 | ||
176 | static ssize_t start_show(struct firmware_map_entry *entry, char *buf) | |
177 | { | |
78681ac0 RD |
178 | return snprintf(buf, PAGE_SIZE, "0x%llx\n", |
179 | (unsigned long long)entry->start); | |
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180 | } |
181 | ||
182 | static ssize_t end_show(struct firmware_map_entry *entry, char *buf) | |
183 | { | |
78681ac0 RD |
184 | return snprintf(buf, PAGE_SIZE, "0x%llx\n", |
185 | (unsigned long long)entry->end); | |
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186 | } |
187 | ||
188 | static ssize_t type_show(struct firmware_map_entry *entry, char *buf) | |
189 | { | |
190 | return snprintf(buf, PAGE_SIZE, "%s\n", entry->type); | |
191 | } | |
192 | ||
193 | #define to_memmap_attr(_attr) container_of(_attr, struct memmap_attribute, attr) | |
194 | #define to_memmap_entry(obj) container_of(obj, struct firmware_map_entry, kobj) | |
195 | ||
196 | static ssize_t memmap_attr_show(struct kobject *kobj, | |
197 | struct attribute *attr, char *buf) | |
198 | { | |
199 | struct firmware_map_entry *entry = to_memmap_entry(kobj); | |
200 | struct memmap_attribute *memmap_attr = to_memmap_attr(attr); | |
201 | ||
202 | return memmap_attr->show(entry, buf); | |
203 | } | |
204 | ||
205 | /* | |
206 | * Initialises stuff and adds the entries in the map_entries list to | |
207 | * sysfs. Important is that firmware_map_add() and firmware_map_add_early() | |
31bad924 BW |
208 | * must be called before late_initcall. That's just because that function |
209 | * is called as late_initcall() function, which means that if you call | |
210 | * firmware_map_add() or firmware_map_add_early() afterwards, the entries | |
211 | * are not added to sysfs. | |
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212 | */ |
213 | static int __init memmap_init(void) | |
214 | { | |
215 | int i = 0; | |
216 | struct firmware_map_entry *entry; | |
217 | struct kset *memmap_kset; | |
218 | ||
219 | memmap_kset = kset_create_and_add("memmap", NULL, firmware_kobj); | |
31bad924 | 220 | if (WARN_ON(!memmap_kset)) |
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221 | return -ENOMEM; |
222 | ||
223 | list_for_each_entry(entry, &map_entries, list) { | |
224 | entry->kobj.kset = memmap_kset; | |
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225 | if (kobject_add(&entry->kobj, NULL, "%d", i++)) |
226 | kobject_put(&entry->kobj); | |
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227 | } |
228 | ||
229 | return 0; | |
230 | } | |
231 | late_initcall(memmap_init); | |
232 |