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
|
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -21,6 +21,8 @@
#include <linux/root_dev.h>
#include <linux/magic.h>
+#define MTD_ERASE_PARTIAL 0x8000 /* partition only covers parts of an erase block */
+
/* Our partition linked list */
static LIST_HEAD(mtd_partitions);
@@ -226,13 +228,60 @@ static int part_erase(struct mtd_info *m
return -EROFS;
if (instr->addr >= mtd->size)
return -EINVAL;
+
+ instr->partial_start = false;
+ if (mtd->flags & MTD_ERASE_PARTIAL) {
+ size_t readlen = 0;
+ u64 mtd_ofs;
+
+ instr->erase_buf = kmalloc(part->master->erasesize, GFP_ATOMIC);
+ if (!instr->erase_buf)
+ return -ENOMEM;
+
+ mtd_ofs = part->offset + instr->addr;
+ instr->erase_buf_ofs = do_div(mtd_ofs, part->master->erasesize);
+
+ if (instr->erase_buf_ofs > 0) {
+ instr->addr -= instr->erase_buf_ofs;
+ ret = part->master->read(part->master,
+ instr->addr + part->offset,
+ part->master->erasesize,
+ &readlen, instr->erase_buf);
+
+ instr->partial_start = true;
+ } else {
+ mtd_ofs = part->offset + part->mtd.size;
+ instr->erase_buf_ofs = part->master->erasesize -
+ do_div(mtd_ofs, part->master->erasesize);
+
+ if (instr->erase_buf_ofs > 0) {
+ instr->len += instr->erase_buf_ofs;
+ ret = part->master->read(part->master,
+ part->offset + instr->addr +
+ instr->len - part->master->erasesize,
+ part->master->erasesize, &readlen,
+ instr->erase_buf);
+ } else {
+ ret = 0;
+ }
+ }
+ if (ret < 0) {
+ kfree(instr->erase_buf);
+ return ret;
+ }
+
+ }
+
instr->addr += part->offset;
ret = part->master->erase(part->master, instr);
if (ret) {
if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
instr->fail_addr -= part->offset;
instr->addr -= part->offset;
+ if (mtd->flags & MTD_ERASE_PARTIAL)
+ kfree(instr->erase_buf);
}
+
return ret;
}
@@ -240,7 +289,25 @@ void mtd_erase_callback(struct erase_inf
{
if (instr->mtd->erase == part_erase) {
struct mtd_part *part = PART(instr->mtd);
+ size_t wrlen = 0;
+ if (instr->mtd->flags & MTD_ERASE_PARTIAL) {
+ if (instr->partial_start) {
+ part->master->write(part->master,
+ instr->addr, instr->erase_buf_ofs,
+ &wrlen, instr->erase_buf);
+ instr->addr += instr->erase_buf_ofs;
+ } else {
+ instr->len -= instr->erase_buf_ofs;
+ part->master->write(part->master,
+ instr->addr + instr->len,
+ instr->erase_buf_ofs, &wrlen,
+ instr->erase_buf +
+ part->master->erasesize -
+ instr->erase_buf_ofs);
+ }
+ kfree(instr->erase_buf);
+ }
if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
instr->fail_addr -= part->offset;
instr->addr -= part->offset;
@@ -473,18 +540,24 @@ static struct mtd_part *add_one_partitio
if ((slave->mtd.flags & MTD_WRITEABLE) &&
mtd_mod_by_eb(slave->offset, &slave->mtd)) {
/* Doesn't start on a boundary of major erase size */
- /* FIXME: Let it be writable if it is on a boundary of
- * _minor_ erase size though */
- slave->mtd.flags &= ~MTD_WRITEABLE;
- printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
- part->name);
+ slave->mtd.flags |= MTD_ERASE_PARTIAL;
+ if (((u32) slave->mtd.size) > master->erasesize)
+ slave->mtd.flags &= ~MTD_WRITEABLE;
+ else
+ slave->mtd.erasesize = slave->mtd.size;
}
if ((slave->mtd.flags & MTD_WRITEABLE) &&
- mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
- slave->mtd.flags &= ~MTD_WRITEABLE;
- printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
- part->name);
- }
+ mtd_mod_by_eb(slave->offset + slave->mtd.size, &slave->mtd)) {
+ slave->mtd.flags |= MTD_ERASE_PARTIAL;
+
+ if ((u32) slave->mtd.size > master->erasesize)
+ slave->mtd.flags &= ~MTD_WRITEABLE;
+ else
+ slave->mtd.erasesize = slave->mtd.size;
+ }
+ if ((slave->mtd.flags & (MTD_ERASE_PARTIAL|MTD_WRITEABLE)) == MTD_ERASE_PARTIAL)
+ printk(KERN_WARNING"mtd: partition \"%s\" must either start or end on erase block boundary or be smaller than an erase block -- forcing read-only\n",
+ part->name);
slave->mtd.ecclayout = master->ecclayout;
if (master->block_isbad) {
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -46,6 +46,10 @@ struct erase_info {
u_long priv;
u_char state;
struct erase_info *next;
+
+ u8 *erase_buf;
+ u32 erase_buf_ofs;
+ bool partial_start;
};
struct mtd_erase_region_info {
|
