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
229
230
231
232
233
234
235
236
237
238
|
From cb9e7995c29b8c25bd84b3f47797d67dbf6dfd0e Mon Sep 17 00:00:00 2001
From: John Thomson <git@johnthomson.fastmail.com.au>
Date: Fri, 25 Dec 2020 18:50:08 +1000
Subject: [PATCH 45/96] mtd: spi-nor: write support for minor aligned
partitions
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Do not prevent writing to mtd partitions where a partition boundary sits
on a minor erasesize boundary.
This addresses a FIXME that has been present since the start of the
linux git history:
/* 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 */
Allow a uniform erase region spi-nor device to be configured
to use the non-uniform erase regions code path for an erase with:
CONFIG_MTD_SPI_NOR_USE_VARIABLE_ERASE=y
On supporting hardware (SECT_4K: majority of current SPI-NOR device)
provide the facility for an erase to use the least number
of SPI-NOR operations, as well as access to 4K erase without
requiring CONFIG_MTD_SPI_NOR_USE_4K_SECTORS
Introduce erasesize_minor to the mtd struct,
the smallest erasesize supported by the device
On existing devices, this is useful where write support is wanted
for data on a 4K partition, such as some u-boot-env partitions,
or RouterBoot soft_config, while still netting the performance
benefits of using 64K sectors
Performance:
time mtd erase firmware
OpenWrt 5.10 ramips MT7621 w25q128jv 0xfc0000 partition length
Without this patch
MTD_SPI_NOR_USE_4K_SECTORS=y |n
real 2m 11.66s |0m 50.86s
user 0m 0.00s |0m 0.00s
sys 1m 56.20s |0m 50.80s
With this patch
MTD_SPI_NOR_USE_VARIABLE_ERASE=n|y |4K_SECTORS=y
real 0m 51.68s |0m 50.85s |2m 12.89s
user 0m 0.00s |0m 0.00s |0m 0.01s
sys 0m 46.94s |0m 50.38s |2m 12.46s
Signed-off-by: John Thomson <git@johnthomson.fastmail.com.au>
Signed-off-by: Thibaut VARÈNE <hacks+kernel@slashdirt.org>
---
drivers/mtd/mtdcore.c | 10 ++++++++++
drivers/mtd/mtdpart.c | 35 +++++++++++++++++++++++++----------
drivers/mtd/spi-nor/Kconfig | 10 ++++++++++
drivers/mtd/spi-nor/core.c | 11 +++++++++--
include/linux/mtd/mtd.h | 2 ++
5 files changed, 56 insertions(+), 12 deletions(-)
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 9eb0680db312..ccb80197d960 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -168,6 +168,15 @@ static ssize_t mtd_erasesize_show(struct device *dev,
}
MTD_DEVICE_ATTR_RO(erasesize);
+static ssize_t mtd_erasesize_minor_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct mtd_info *mtd = dev_get_drvdata(dev);
+
+ return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->erasesize_minor);
+}
+MTD_DEVICE_ATTR_RO(erasesize_minor);
+
static ssize_t mtd_writesize_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -313,6 +322,7 @@ static struct attribute *mtd_attrs[] = {
&dev_attr_flags.attr,
&dev_attr_size.attr,
&dev_attr_erasesize.attr,
+ &dev_attr_erasesize_minor.attr,
&dev_attr_writesize.attr,
&dev_attr_subpagesize.attr,
&dev_attr_oobsize.attr,
diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index f1ed12aae1fe..0b7be183a1f6 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -41,6 +41,7 @@ static struct mtd_info *allocate_partition(struct mtd_info *parent,
struct mtd_info *master = mtd_get_master(parent);
int wr_alignment = (parent->flags & MTD_NO_ERASE) ?
master->writesize : master->erasesize;
+ int wr_alignment_minor = 0;
u64 parent_size = mtd_is_partition(parent) ?
parent->part.size : parent->size;
struct mtd_info *child;
@@ -165,6 +166,7 @@ static struct mtd_info *allocate_partition(struct mtd_info *parent,
} else {
/* Single erase size */
child->erasesize = master->erasesize;
+ child->erasesize_minor = master->erasesize_minor;
}
/*
@@ -172,26 +174,39 @@ static struct mtd_info *allocate_partition(struct mtd_info *parent,
* exposes several regions with different erasesize. Adjust
* wr_alignment accordingly.
*/
- if (!(child->flags & MTD_NO_ERASE))
+ if (!(child->flags & MTD_NO_ERASE)) {
wr_alignment = child->erasesize;
+ wr_alignment_minor = child->erasesize_minor;
+ }
tmp = mtd_get_master_ofs(child, 0);
remainder = do_div(tmp, wr_alignment);
if ((child->flags & MTD_WRITEABLE) && remainder) {
- /* 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 */
- child->flags &= ~MTD_WRITEABLE;
- printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase/write block boundary -- force read-only\n",
- part->name);
+ if (wr_alignment_minor) {
+ /* rely on minor being a factor of major erasesize */
+ tmp = remainder;
+ remainder = do_div(tmp, wr_alignment_minor);
+ }
+ if (remainder) {
+ child->flags &= ~MTD_WRITEABLE;
+ printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase/write block boundary -- force read-only\n",
+ part->name);
+ }
}
tmp = mtd_get_master_ofs(child, 0) + child->part.size;
remainder = do_div(tmp, wr_alignment);
if ((child->flags & MTD_WRITEABLE) && remainder) {
- child->flags &= ~MTD_WRITEABLE;
- printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase/write block -- force read-only\n",
- part->name);
+ if (wr_alignment_minor) {
+ tmp = remainder;
+ remainder = do_div(tmp, wr_alignment_minor);
+ }
+
+ if (remainder) {
+ child->flags &= ~MTD_WRITEABLE;
+ printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase/write block -- force read-only\n",
+ part->name);
+ }
}
child->size = child->part.size;
diff --git a/drivers/mtd/spi-nor/Kconfig b/drivers/mtd/spi-nor/Kconfig
index 24cd25de2b8b..09df9f1a8127 100644
--- a/drivers/mtd/spi-nor/Kconfig
+++ b/drivers/mtd/spi-nor/Kconfig
@@ -10,6 +10,16 @@ menuconfig MTD_SPI_NOR
if MTD_SPI_NOR
+config MTD_SPI_NOR_USE_VARIABLE_ERASE
+ bool "Disable uniform_erase to allow use of all hardware supported erasesizes"
+ depends on !MTD_SPI_NOR_USE_4K_SECTORS
+ default n
+ help
+ Allow mixed use of all hardware supported erasesizes,
+ by forcing spi_nor to use the multiple eraseregions code path.
+ For example: A 68K erase will use one 64K erase, and one 4K erase
+ on supporting hardware.
+
config MTD_SPI_NOR_USE_4K_SECTORS
bool "Use small 4096 B erase sectors"
default y
diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index e758ebfe1a9f..f237f050b43c 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -1048,6 +1048,8 @@ static u8 spi_nor_convert_3to4_erase(u8 opcode)
static bool spi_nor_has_uniform_erase(const struct spi_nor *nor)
{
+ if (IS_ENABLED(CONFIG_MTD_SPI_NOR_USE_VARIABLE_ERASE))
+ return false;
return !!nor->params->erase_map.uniform_erase_type;
}
@@ -2144,6 +2146,7 @@ static int spi_nor_select_erase(struct spi_nor *nor)
{
struct spi_nor_erase_map *map = &nor->params->erase_map;
const struct spi_nor_erase_type *erase = NULL;
+ const struct spi_nor_erase_type *erase_minor = NULL;
struct mtd_info *mtd = &nor->mtd;
u32 wanted_size = nor->info->sector_size;
int i;
@@ -2176,8 +2179,9 @@ static int spi_nor_select_erase(struct spi_nor *nor)
*/
for (i = SNOR_ERASE_TYPE_MAX - 1; i >= 0; i--) {
if (map->erase_type[i].size) {
- erase = &map->erase_type[i];
- break;
+ if (!erase)
+ erase = &map->erase_type[i];
+ erase_minor = &map->erase_type[i];
}
}
@@ -2185,6 +2189,9 @@ static int spi_nor_select_erase(struct spi_nor *nor)
return -EINVAL;
mtd->erasesize = erase->size;
+ if (IS_ENABLED(CONFIG_MTD_SPI_NOR_USE_VARIABLE_ERASE) &&
+ erase_minor && erase_minor->size < erase->size)
+ mtd->erasesize_minor = erase_minor->size;
return 0;
}
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index e2359a3569f0..cd7807a23123 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -238,6 +238,8 @@ struct mtd_info {
* information below if they desire
*/
uint32_t erasesize;
+ /* "Minor" (smallest) erase size supported by the whole device */
+ uint32_t erasesize_minor;
/* Minimal writable flash unit size. In case of NOR flash it is 1 (even
* though individual bits can be cleared), in case of NAND flash it is
* one NAND page (or half, or one-fourths of it), in case of ECC-ed NOR
--
2.37.2
|
