1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
|
/*
* Simple MTD partitioning layer
*
* (C) 2000 Nicolas Pitre <nico@cam.org>
*
* This code is GPL
*
* $Id: mtdpart.c,v 1.7 2000/12/09 23:29:47 dwmw2 Exp $
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
/* Our partition linked list */
static LIST_HEAD(mtd_partitions);
/* Our partition node structure */
struct mtd_part {
struct mtd_info mtd;
struct mtd_info *master;
loff_t offset;
int index;
struct list_head list;
};
/*
* Given a pointer to the MTD object in the mtd_part structure, we can retrieve
* the pointer to that structure with this macro.
*/
#define PART(x) ((struct mtd_part *)(x))
/*
* MTD methods which simply translate the effective address and pass through
* to the _real_ device.
*/
static int part_read (struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, u_char *buf)
{
struct mtd_part *part = PART(mtd);
if (from >= mtd->size)
len = 0;
else if (from + len > mtd->size)
len = mtd->size - from;
return part->master->read (part->master, from + part->offset,
len, retlen, buf);
}
static int part_write (struct mtd_info *mtd, loff_t to, size_t len,
size_t *retlen, const u_char *buf)
{
struct mtd_part *part = PART(mtd);
if (!(mtd->flags & MTD_WRITEABLE))
return -EROFS;
if (to >= mtd->size)
len = 0;
else if (to + len > mtd->size)
len = mtd->size - to;
return part->master->write (part->master, to + part->offset,
len, retlen, buf);
}
static int part_writev (struct mtd_info *mtd, const struct iovec *vecs,
unsigned long count, loff_t to, size_t *retlen)
{
struct mtd_part *part = PART(mtd);
if (!(mtd->flags & MTD_WRITEABLE))
return -EROFS;
return part->master->writev (part->master, vecs, count,
to + part->offset, retlen);
}
static int part_readv (struct mtd_info *mtd, struct iovec *vecs,
unsigned long count, loff_t from, size_t *retlen)
{
struct mtd_part *part = PART(mtd);
return part->master->readv (part->master, vecs, count,
from + part->offset, retlen);
}
static int part_erase (struct mtd_info *mtd, struct erase_info *instr)
{
struct mtd_part *part = PART(mtd);
if (!(mtd->flags & MTD_WRITEABLE))
return -EROFS;
if (instr->addr >= mtd->size)
return -EINVAL;
instr->addr += part->offset;
return part->master->erase(part->master, instr);
}
static int part_lock (struct mtd_info *mtd, loff_t ofs, size_t len)
{
struct mtd_part *part = PART(mtd);
return part->master->lock(part->master, ofs + part->offset, len);
}
static int part_unlock (struct mtd_info *mtd, loff_t ofs, size_t len)
{
struct mtd_part *part = PART(mtd);
return part->master->unlock(part->master, ofs + part->offset, len);
}
/*
* This function unregisters and destroy all slave MTD objects which are
* attached to the given master MTD object.
*/
int del_mtd_partitions(struct mtd_info *master)
{
struct list_head *node;
struct mtd_part *slave;
for (node = mtd_partitions.next;
node != &mtd_partitions;
node = node->next) {
slave = list_entry(node, struct mtd_part, list);
if (slave->master == master) {
struct list_head *prev = node->prev;
__list_del(prev, node->next);
del_mtd_device(&slave->mtd);
kfree(slave);
node = prev;
MOD_DEC_USE_COUNT;
}
}
return 0;
}
/*
* This function, given a master MTD object and a partition table, creates
* and registers slave MTD objects which are bound to the master according to
* the partition definitions.
* (Q: should we register the master MTD object as well?)
*/
int add_mtd_partitions(struct mtd_info *master,
struct mtd_partition *parts,
int nbparts)
{
struct mtd_part *slave;
u_long cur_offset = 0;
int i;
for (i = 0; i < nbparts; i++) {
/* allocate the partition structure */
slave = kmalloc (sizeof(*slave), GFP_KERNEL);
if (!slave) {
printk ("memory allocation error while creating partitions for \"%s\"\n",
master->name);
del_mtd_partitions(master);
return -ENOMEM;
}
list_add(&slave->list, &mtd_partitions);
/* set up the MTD object for this partition */
slave->mtd = *master;
slave->mtd.name = parts[i].name;
slave->mtd.size = parts[i].size;
slave->mtd.flags &= ~parts[i].mask_flags;
slave->mtd.read = part_read;
slave->mtd.write = part_write;
if (slave->mtd.writev)
slave->mtd.writev = part_writev;
if (slave->mtd.readv)
slave->mtd.readv = part_readv;
if (slave->mtd.lock)
slave->mtd.lock = part_lock;
if (slave->mtd.unlock)
slave->mtd.unlock = part_unlock;
slave->mtd.erase = part_erase;
slave->master = master;
slave->offset = parts[i].offset;
slave->index = i;
if (slave->offset == 0)
slave->offset = cur_offset;
if (slave->mtd.size == 0)
slave->mtd.size = master->size - slave->offset;
cur_offset = slave->offset + slave->mtd.size;
/* let's do some sanity checks */
if ((slave->mtd.flags & MTD_WRITEABLE) &&
(parts[i].offset % master->erasesize)) {
slave->mtd.flags &= ~MTD_WRITEABLE;
printk ("mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
parts[i].name);
}
if ((slave->mtd.flags & MTD_WRITEABLE) &&
(parts[i].size % master->erasesize)) {
slave->mtd.flags &= ~MTD_WRITEABLE;
printk ("mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
parts[i].name);
}
if (parts[i].offset >= master->size) {
/* let's register it anyway to preserve ordering */
slave->offset = 0;
slave->mtd.size = 0;
printk ("mtd: partition \"%s\" is out of reach -- disabled\n",
parts[i].name);
}
if (parts[i].offset + parts[i].size > master->size) {
slave->mtd.size = master->size - parts[i].offset;
printk ("mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#lx\n",
parts[i].name, master->name, slave->mtd.size);
}
/* register our partition */
add_mtd_device(&slave->mtd);
MOD_INC_USE_COUNT;
}
return 0;
}
EXPORT_SYMBOL(add_mtd_partitions);
EXPORT_SYMBOL(del_mtd_partitions);
|
