[PATCH] phram: Allow the user to set the erase page size.
Permit the user to specify the erase page size as a parameter.
This solves two problems:
- phram can access images made by mkfs.jffs2. mkfs.jffs2 won't
create images with erase sizes less than 8KiB; many architectures
define PAGE_SIZE as 4KiB.
- Allows more effective use of small capacity devices. JFFS2
needs somewhere between 2 and 5 empty pages for garbage collection;
and for an NVRAM part with only 32KiB of space, a smaller erase page
allows much better utilization in applications where garbage collection
is important.
Signed-off-by: Patrick O'Grady
Reviewed-by: Joern Engel
Link:
https://lore.kernel.org/lkml/CAJ7m5OqYv_=JB9NhHsqBsa8YU0DFRoP7C+W10PY22wonAGJK=a...@mail.gmail.com/
[Guohua Zhong: fix token array index out of bounds and update patch for kernel
master branch]
Signed-off-by: Guohua Zhong
---
drivers/mtd/devices/phram.c | 52 +
1 file changed, 34 insertions(+), 18 deletions(-)
diff --git a/drivers/mtd/devices/phram.c b/drivers/mtd/devices/phram.c
index 087b5e86d1bf..1729b94b2abf 100644
--- a/drivers/mtd/devices/phram.c
+++ b/drivers/mtd/devices/phram.c
@@ -6,14 +6,14 @@
* Usage:
*
* one commend line parameter per device, each in the form:
- * phram=,,
+ * phram=,,[,]
* may be up to 63 characters.
- * and can be octal, decimal or hexadecimal. If followed
+ * , , and can be octal, decimal or hexadecimal. If
followed
* by "ki", "Mi" or "Gi", the numbers will be interpreted as kilo, mega or
- * gigabytes.
+ * gigabytes. is optional and defaults to PAGE_SIZE.
*
* Example:
- * phram=swap,64Mi,128Mi phram=test,900Mi,1Mi
+ * phram=swap,64Mi,128Mi phram=test,900Mi,1Mi,64Ki
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -26,6 +26,7 @@
#include
#include
#include
+#include
struct phram_mtd_list {
struct mtd_info mtd;
@@ -88,7 +89,7 @@ static void unregister_devices(void)
}
}
-static int register_device(char *name, phys_addr_t start, size_t len)
+static int register_device(char *name, phys_addr_t start, size_t len, uint32_t
erasesize)
{
struct phram_mtd_list *new;
int ret = -ENOMEM;
@@ -115,7 +116,7 @@ static int register_device(char *name, phys_addr_t start,
size_t len)
new->mtd._write = phram_write;
new->mtd.owner = THIS_MODULE;
new->mtd.type = MTD_RAM;
- new->mtd.erasesize = PAGE_SIZE;
+ new->mtd.erasesize = erasesize;
new->mtd.writesize = 1;
ret = -EAGAIN;
@@ -204,22 +205,23 @@ static inline void kill_final_newline(char *str)
static int phram_init_called;
/*
* This shall contain the module parameter if any. It is of the form:
- * - phram=,, for module case
- * - phram.phram=,, for built-in case
- * We leave 64 bytes for the device name, 20 for the address and 20 for the
- * size.
- * Example: phram.phram=rootfs,0xa000,512Mi
+ * - phram=,,[,] for module case
+ * - phram.phram=,,[,] for built-in case
+ * We leave 64 bytes for the device name, 20 for the address , 20 for the
+ * size and 20 for the erasesize.
+ * Example: phram.phram=rootfs,0xa000,512Mi,65536
*/
-static char phram_paramline[64 + 20 + 20];
+static char phram_paramline[64 + 20 + 20 + 20];
#endif
static int phram_setup(const char *val)
{
- char buf[64 + 20 + 20], *str = buf;
- char *token[3];
+ char buf[64 + 20 + 20 + 20], *str = buf;
+ char *token[4];
char *name;
uint64_t start;
uint64_t len;
+ uint64_t erasesize = PAGE_SIZE;
int i, ret;
if (strnlen(val, sizeof(buf)) >= sizeof(buf))
@@ -228,7 +230,7 @@ static int phram_setup(const char *val)
strcpy(str, val);
kill_final_newline(str);
- for (i = 0; i < 3; i++)
+ for (i = 0; i < 4; i++)
token[i] = strsep(, ",");
if (str)
@@ -253,11 +255,25 @@ static int phram_setup(const char *val)
goto error;
}
- ret = register_device(name, start, len);
+ if (token[3]) {
+ ret = parse_num64(, token[3]);
+ if (ret) {
+ parse_err("illegal erasesize\n");
+ goto error;
+ }
+ }
+
+ if (len == 0 || erasesize == 0 || erasesize > len
+ || erasesize > UINT_MAX || do_div(len, (uint32_t)erasesize) != 0) {
+ parse_err("illegal erasesize or len\n");
+ goto error;
+ }
+
+ ret = register_device(name, start, len, (uint32_t)erasesize);
if (ret)
goto error;
- pr_info("%s device: %#llx at %#llx\n", name, len, start);
+ pr_info("%s device: %#llx at %#llx for erasesize %#llx\n", name, len,
start, erasesize);
return 0;
error:
@@ -298,7 +314,7 @@ static int phram_param_call(const char *val, const struct
kernel_param *kp)
}
module_param_call(phram, phram_param_call, NULL, NULL, 0200);
-MODULE_PARM_DESC(phram, "Memory region to map.
\"phram=,,\"");
Re: [PATCH] phram: Allow the user to set the erase page size.
Hi Guohua,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on linus/master]
[also build test ERROR on v5.10-rc5 next-20201123]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url:
https://github.com/0day-ci/linux/commits/Guohua-Zhong/phram-Allow-the-user-to-set-the-erase-page-size/20201124-141421
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
d5beb3140f91b1c8a3d41b14d729aefa4dcc58bc
config: i386-randconfig-r034-20201124 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
reproduce (this is a W=1 build):
#
https://github.com/0day-ci/linux/commit/6ec7a653a663b6a638f767aa844a685fdd1463d2
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review
Guohua-Zhong/phram-Allow-the-user-to-set-the-erase-page-size/20201124-141421
git checkout 6ec7a653a663b6a638f767aa844a685fdd1463d2
# save the attached .config to linux build tree
make W=1 ARCH=i386
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot
All errors (new ones prefixed by >>):
ld: drivers/mtd/devices/phram.o: in function `phram_setup':
>> drivers/mtd/devices/phram.c:266: undefined reference to `__umoddi3'
vim +266 drivers/mtd/devices/phram.c
215
216 static int phram_setup(const char *val)
217 {
218 char buf[64 + 20 + 20 + 20], *str = buf;
219 char *token[4];
220 char *name;
221 uint64_t start;
222 uint64_t len;
223 uint64_t erasesize = PAGE_SIZE;
224 int i, ret;
225
226 if (strnlen(val, sizeof(buf)) >= sizeof(buf))
227 parse_err("parameter too long\n");
228
229 strcpy(str, val);
230 kill_final_newline(str);
231
232 for (i = 0; i < 4; i++)
233 token[i] = strsep(, ",");
234
235 if (str)
236 parse_err("too many arguments\n");
237
238 if (!token[2])
239 parse_err("not enough arguments\n");
240
241 ret = parse_name(, token[0]);
242 if (ret)
243 return ret;
244
245 ret = parse_num64(, token[1]);
246 if (ret) {
247 parse_err("illegal start address\n");
248 goto error;
249 }
250
251 ret = parse_num64(, token[2]);
252 if (ret) {
253 parse_err("illegal device length\n");
254 goto error;
255 }
256
257 if (token[3]) {
258 ret = parse_num64(, token[3]);
259 if (ret) {
260 parse_err("illegal erasesize\n");
261 goto error;
262 }
263 }
264
265 if (len == 0 || erasesize == 0 || erasesize > len
> 266 || erasesize > UINT_MAX || len % erasesize != 0) {
267 parse_err("illegal erasesize or len\n");
268 goto error;
269 }
270
271 ret = register_device(name, start, len, (uint32_t)erasesize);
272 if (ret)
273 goto error;
274
275 pr_info("%s device: %#llx at %#llx for erasesize %#llx\n",
name, len, start, erasesize);
276 return 0;
277
278 error:
279 kfree(name);
280 return ret;
281 }
282
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-...@lists.01.org
.config.gz
Description: application/gzip
Re: [PATCH] phram: Allow the user to set the erase page size.
Hi Guohua, Thank you for the patch! Yet something to improve: [auto build test ERROR on linus/master] [also build test ERROR on v5.10-rc5 next-20201123] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Guohua-Zhong/phram-Allow-the-user-to-set-the-erase-page-size/20201124-141421 base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git d5beb3140f91b1c8a3d41b14d729aefa4dcc58bc config: microblaze-randconfig-r012-20201124 (attached as .config) compiler: microblaze-linux-gcc (GCC) 9.3.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://github.com/0day-ci/linux/commit/6ec7a653a663b6a638f767aa844a685fdd1463d2 git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Guohua-Zhong/phram-Allow-the-user-to-set-the-erase-page-size/20201124-141421 git checkout 6ec7a653a663b6a638f767aa844a685fdd1463d2 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=microblaze If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All errors (new ones prefixed by >>, old ones prefixed by <<): >> ERROR: modpost: "__umoddi3" [drivers/mtd/devices/phram.ko] undefined! --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-...@lists.01.org .config.gz Description: application/gzip
[PATCH] phram: Allow the user to set the erase page size.
Permit the user to specify the erase page size as a parameter.
This solves two problems:
- phram can access images made by mkfs.jffs2. mkfs.jffs2 won't
create images with erase sizes less than 8KiB; many architectures
define PAGE_SIZE as 4KiB.
- Allows more effective use of small capacity devices. JFFS2
needs somewhere between 2 and 5 empty pages for garbage collection;
and for an NVRAM part with only 32KiB of space, a smaller erase page
allows much better utilization in applications where garbage collection
is important.
Signed-off-by: Patrick O'Grady
Reviewed-by: Joern Engel
Link:
https://lore.kernel.org/lkml/CAJ7m5OqYv_=JB9NhHsqBsa8YU0DFRoP7C+W10PY22wonAGJK=a...@mail.gmail.com/
[Guohua Zhong: fix token array index out of bounds and update patch for kernel
master branch]
Signed-off-by: Guohua Zhong
---
drivers/mtd/devices/phram.c | 51 +
1 file changed, 33 insertions(+), 18 deletions(-)
diff --git a/drivers/mtd/devices/phram.c b/drivers/mtd/devices/phram.c
index 087b5e86d1bf..3ac766b65bf2 100644
--- a/drivers/mtd/devices/phram.c
+++ b/drivers/mtd/devices/phram.c
@@ -6,14 +6,14 @@
* Usage:
*
* one commend line parameter per device, each in the form:
- * phram=,,
+ * phram=,,[,]
* may be up to 63 characters.
- * and can be octal, decimal or hexadecimal. If followed
+ * , , and can be octal, decimal or hexadecimal. If
followed
* by "ki", "Mi" or "Gi", the numbers will be interpreted as kilo, mega or
- * gigabytes.
+ * gigabytes. is optional and defaults to PAGE_SIZE.
*
* Example:
- * phram=swap,64Mi,128Mi phram=test,900Mi,1Mi
+ * phram=swap,64Mi,128Mi phram=test,900Mi,1Mi,64Ki
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -88,7 +88,7 @@ static void unregister_devices(void)
}
}
-static int register_device(char *name, phys_addr_t start, size_t len)
+static int register_device(char *name, phys_addr_t start, size_t len, uint32_t
erasesize)
{
struct phram_mtd_list *new;
int ret = -ENOMEM;
@@ -115,7 +115,7 @@ static int register_device(char *name, phys_addr_t start,
size_t len)
new->mtd._write = phram_write;
new->mtd.owner = THIS_MODULE;
new->mtd.type = MTD_RAM;
- new->mtd.erasesize = PAGE_SIZE;
+ new->mtd.erasesize = erasesize;
new->mtd.writesize = 1;
ret = -EAGAIN;
@@ -204,22 +204,23 @@ static inline void kill_final_newline(char *str)
static int phram_init_called;
/*
* This shall contain the module parameter if any. It is of the form:
- * - phram=,, for module case
- * - phram.phram=,, for built-in case
- * We leave 64 bytes for the device name, 20 for the address and 20 for the
- * size.
- * Example: phram.phram=rootfs,0xa000,512Mi
+ * - phram=,,[,] for module case
+ * - phram.phram=,,[,] for built-in case
+ * We leave 64 bytes for the device name, 20 for the address , 20 for the
+ * size and 20 for the erasesize.
+ * Example: phram.phram=rootfs,0xa000,512Mi,65536
*/
-static char phram_paramline[64 + 20 + 20];
+static char phram_paramline[64 + 20 + 20 + 20];
#endif
static int phram_setup(const char *val)
{
- char buf[64 + 20 + 20], *str = buf;
- char *token[3];
+ char buf[64 + 20 + 20 + 20], *str = buf;
+ char *token[4];
char *name;
uint64_t start;
uint64_t len;
+ uint64_t erasesize = PAGE_SIZE;
int i, ret;
if (strnlen(val, sizeof(buf)) >= sizeof(buf))
@@ -228,7 +229,7 @@ static int phram_setup(const char *val)
strcpy(str, val);
kill_final_newline(str);
- for (i = 0; i < 3; i++)
+ for (i = 0; i < 4; i++)
token[i] = strsep(, ",");
if (str)
@@ -253,11 +254,25 @@ static int phram_setup(const char *val)
goto error;
}
- ret = register_device(name, start, len);
+ if (token[3]) {
+ ret = parse_num64(, token[3]);
+ if (ret) {
+ parse_err("illegal erasesize\n");
+ goto error;
+ }
+ }
+
+ if (len == 0 || erasesize == 0 || erasesize > len
+ || erasesize > UINT_MAX || len % erasesize != 0) {
+ parse_err("illegal erasesize or len\n");
+ goto error;
+ }
+
+ ret = register_device(name, start, len, (uint32_t)erasesize);
if (ret)
goto error;
- pr_info("%s device: %#llx at %#llx\n", name, len, start);
+ pr_info("%s device: %#llx at %#llx for erasesize %#llx\n", name, len,
start, erasesize);
return 0;
error:
@@ -298,7 +313,7 @@ static int phram_param_call(const char *val, const struct
kernel_param *kp)
}
module_param_call(phram, phram_param_call, NULL, NULL, 0200);
-MODULE_PARM_DESC(phram, "Memory region to map.
\"phram=,,\"");
+MODULE_PARM_DESC(phram, "Memory region to map.
\"phram=,,[,]\"");
static int __init init_phram(void)
--
2.12.3
Re: [PATCH] phram: Allow the user to set the erase page size.
On Fri, 2013-02-15 at 12:35 -0800, Patrick O'Grady wrote: > From: Patrick O'Grady > > Permit the user to specify the erase page size as a parameter. > This solves two problems: > > - phram can access images made by mkfs.jffs2. mkfs.jffs2 won't > create images with erase sizes less than 8KiB; many architectures > define PAGE_SIZE as 4KiB. > > - Allows more effective use of small capacity devices. JFFS2 > needs somewhere between 2 and 5 empty pages for garbage collection; > and for an NVRAM part with only 32KiB of space, a smaller erase page > allows much better utilization in applications where garbage collection > is important. Unfortunately, the patch is line-wrapped and not applicable to the latest kernel tree. Would you please refresh and re-send properly? -- Best Regards, Artem Bityutskiy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] phram: Allow the user to set the erase page size.
On Fri, 2013-02-15 at 12:35 -0800, Patrick O'Grady wrote: From: Patrick O'Grady patr...@baymotion.com Permit the user to specify the erase page size as a parameter. This solves two problems: - phram can access images made by mkfs.jffs2. mkfs.jffs2 won't create images with erase sizes less than 8KiB; many architectures define PAGE_SIZE as 4KiB. - Allows more effective use of small capacity devices. JFFS2 needs somewhere between 2 and 5 empty pages for garbage collection; and for an NVRAM part with only 32KiB of space, a smaller erase page allows much better utilization in applications where garbage collection is important. Unfortunately, the patch is line-wrapped and not applicable to the latest kernel tree. Would you please refresh and re-send properly? -- Best Regards, Artem Bityutskiy -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] phram: Allow the user to set the erase page size.
On Fri, 15 February 2013 12:35:46 -0800, Patrick O'Grady wrote: > > Permit the user to specify the erase page size as a parameter. > This solves two problems: > > - phram can access images made by mkfs.jffs2. mkfs.jffs2 won't > create images with erase sizes less than 8KiB; many architectures > define PAGE_SIZE as 4KiB. > > - Allows more effective use of small capacity devices. JFFS2 > needs somewhere between 2 and 5 empty pages for garbage collection; > and for an NVRAM part with only 32KiB of space, a smaller erase page > allows much better utilization in applications where garbage collection > is important. > > Signed-off-by: Patrick O'Grady I can't see any argument against this. Reviewed-by: Joern Engel Jörn -- "[One] doesn't need to know [...] how to cause a headache in order to take an aspirin." -- Scott Culp, Manager of the Microsoft Security Response Center, 2001 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH] phram: Allow the user to set the erase page size.
From: Patrick O'Grady
Permit the user to specify the erase page size as a parameter.
This solves two problems:
- phram can access images made by mkfs.jffs2. mkfs.jffs2 won't
create images with erase sizes less than 8KiB; many architectures
define PAGE_SIZE as 4KiB.
- Allows more effective use of small capacity devices. JFFS2
needs somewhere between 2 and 5 empty pages for garbage collection;
and for an NVRAM part with only 32KiB of space, a smaller erase page
allows much better utilization in applications where garbage collection
is important.
Signed-off-by: Patrick O'Grady
---
diff --git a/drivers/mtd/devices/phram.c b/drivers/mtd/devices/phram.c
index 67823de..5eee2a6 100644
--- a/drivers/mtd/devices/phram.c
+++ b/drivers/mtd/devices/phram.c
@@ -5,14 +5,15 @@
* Usage:
*
* one commend line parameter per device, each in the form:
- * phram=,,
+ * phram=,,[,]
* may be up to 63 characters.
- * and can be octal, decimal or hexadecimal. If followed
- * by "ki", "Mi" or "Gi", the numbers will be interpreted as kilo, mega or
- * gigabytes.
+ * , , and can be octal, decimal or
+ * hexadecimal. If followed by "ki", "Mi" or "Gi", the numbers
+ * will be interpreted as kilo, mega or gigabytes.
+ * is optional and defaults to PAGE_SIZE.
*
* Example:
- * phram=swap,64Mi,128Mi phram=test,900Mi,1Mi
+ * phram=swap,64Mi,128Mi phram=test,900Mi,1Mi,64Ki
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -94,7 +95,8 @@ static void unregister_devices(void)
}
}
-static int register_device(char *name, unsigned long start, unsigned long len)
+static int register_device(char *name, unsigned long start,
+ unsigned long len, unsigned long erasesize)
{
struct phram_mtd_list *new;
int ret = -ENOMEM;
@@ -121,7 +123,7 @@ static int register_device(char *name, unsigned
long start, unsigned long len)
new->mtd._write = phram_write;
new->mtd.owner = THIS_MODULE;
new->mtd.type = MTD_RAM;
- new->mtd.erasesize = PAGE_SIZE;
+ new->mtd.erasesize = erasesize;
new->mtd.writesize = 1;
ret = -EAGAIN;
@@ -207,21 +209,22 @@ static inline void kill_final_newline(char *str)
/*
* This shall contain the module parameter if any. It is of the form:
- * - phram=,, for module case
- * - phram.phram=,, for built-in case
- * We leave 64 bytes for the device name, 12 for the address and 12 for the
- * size.
- * Example: phram.phram=rootfs,0xa000,512Mi
+ * - phram=,,[,] for module case
+ * - phram.phram=,,[,] for built-in case
+ * We leave 64 bytes for the device name, 12 for the address, 12 for the
+ * size, and 12 for the erasesize.
+ * Example: phram.phram=rootfs,0xa000,512Mi,65536
*/
static __initdata char phram_paramline[64+12+12];
static int __init phram_setup(const char *val)
{
- char buf[64+12+12], *str = buf;
+ char buf[64+12+12+12], *str = buf;
char *token[3];
char *name;
uint32_t start;
uint32_t len;
+ uint32_t erasesize = PAGE_SIZE ;
int i, ret;
if (strnlen(val, sizeof(buf)) >= sizeof(buf))
@@ -230,7 +233,7 @@ static int __init phram_setup(const char *val)
strcpy(str, val);
kill_final_newline(str);
- for (i=0; i<3; i++)
+ for (i = 0; i < 4; i++)
token[i] = strsep(, ",");
if (str)
@@ -255,7 +258,15 @@ static int __init phram_setup(const char *val)
parse_err("illegal device length\n");
}
- ret = register_device(name, start, len);
+ if (token[3]) {
+ ret = parse_num32(, token[3]);
+ if (ret) {
+ kfree(name);
+ parse_err("illegal erase size\n");
+ }
+ }
+
+ ret = register_device(name, start, len, erasesize);
if (!ret)
pr_info("%s device: %#x at %#x\n", name, len, start);
else
@@ -278,7 +289,7 @@ static int __init phram_param_call(const char
*val, struct kernel_param *kp)
}
module_param_call(phram, phram_param_call, NULL, NULL, 000);
-MODULE_PARM_DESC(phram, "Memory region to map.
\"phram=,,\"");
+MODULE_PARM_DESC(phram, "Memory region to map.
\"phram=,,[,]\"");
static int __init init_phram(void)
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[PATCH] phram: Allow the user to set the erase page size.
From: Patrick O'Grady patr...@baymotion.com
Permit the user to specify the erase page size as a parameter.
This solves two problems:
- phram can access images made by mkfs.jffs2. mkfs.jffs2 won't
create images with erase sizes less than 8KiB; many architectures
define PAGE_SIZE as 4KiB.
- Allows more effective use of small capacity devices. JFFS2
needs somewhere between 2 and 5 empty pages for garbage collection;
and for an NVRAM part with only 32KiB of space, a smaller erase page
allows much better utilization in applications where garbage collection
is important.
Signed-off-by: Patrick O'Grady patr...@baymotion.com
---
diff --git a/drivers/mtd/devices/phram.c b/drivers/mtd/devices/phram.c
index 67823de..5eee2a6 100644
--- a/drivers/mtd/devices/phram.c
+++ b/drivers/mtd/devices/phram.c
@@ -5,14 +5,15 @@
* Usage:
*
* one commend line parameter per device, each in the form:
- * phram=name,start,len
+ * phram=name,start,len[,erasesize]
* name may be up to 63 characters.
- * start and len can be octal, decimal or hexadecimal. If followed
- * by ki, Mi or Gi, the numbers will be interpreted as kilo, mega or
- * gigabytes.
+ * start, len, and erasesize can be octal, decimal or
+ * hexadecimal. If followed by ki, Mi or Gi, the numbers
+ * will be interpreted as kilo, mega or gigabytes. erasesize
+ * is optional and defaults to PAGE_SIZE.
*
* Example:
- * phram=swap,64Mi,128Mi phram=test,900Mi,1Mi
+ * phram=swap,64Mi,128Mi phram=test,900Mi,1Mi,64Ki
*/
#define pr_fmt(fmt) KBUILD_MODNAME : fmt
@@ -94,7 +95,8 @@ static void unregister_devices(void)
}
}
-static int register_device(char *name, unsigned long start, unsigned long len)
+static int register_device(char *name, unsigned long start,
+ unsigned long len, unsigned long erasesize)
{
struct phram_mtd_list *new;
int ret = -ENOMEM;
@@ -121,7 +123,7 @@ static int register_device(char *name, unsigned
long start, unsigned long len)
new-mtd._write = phram_write;
new-mtd.owner = THIS_MODULE;
new-mtd.type = MTD_RAM;
- new-mtd.erasesize = PAGE_SIZE;
+ new-mtd.erasesize = erasesize;
new-mtd.writesize = 1;
ret = -EAGAIN;
@@ -207,21 +209,22 @@ static inline void kill_final_newline(char *str)
/*
* This shall contain the module parameter if any. It is of the form:
- * - phram=device,address,size for module case
- * - phram.phram=device,address,size for built-in case
- * We leave 64 bytes for the device name, 12 for the address and 12 for the
- * size.
- * Example: phram.phram=rootfs,0xa000,512Mi
+ * - phram=device,address,size[,erasesize] for module case
+ * - phram.phram=device,address,size[,erasesize] for built-in case
+ * We leave 64 bytes for the device name, 12 for the address, 12 for the
+ * size, and 12 for the erasesize.
+ * Example: phram.phram=rootfs,0xa000,512Mi,65536
*/
static __initdata char phram_paramline[64+12+12];
static int __init phram_setup(const char *val)
{
- char buf[64+12+12], *str = buf;
+ char buf[64+12+12+12], *str = buf;
char *token[3];
char *name;
uint32_t start;
uint32_t len;
+ uint32_t erasesize = PAGE_SIZE ;
int i, ret;
if (strnlen(val, sizeof(buf)) = sizeof(buf))
@@ -230,7 +233,7 @@ static int __init phram_setup(const char *val)
strcpy(str, val);
kill_final_newline(str);
- for (i=0; i3; i++)
+ for (i = 0; i 4; i++)
token[i] = strsep(str, ,);
if (str)
@@ -255,7 +258,15 @@ static int __init phram_setup(const char *val)
parse_err(illegal device length\n);
}
- ret = register_device(name, start, len);
+ if (token[3]) {
+ ret = parse_num32(erasesize, token[3]);
+ if (ret) {
+ kfree(name);
+ parse_err(illegal erase size\n);
+ }
+ }
+
+ ret = register_device(name, start, len, erasesize);
if (!ret)
pr_info(%s device: %#x at %#x\n, name, len, start);
else
@@ -278,7 +289,7 @@ static int __init phram_param_call(const char
*val, struct kernel_param *kp)
}
module_param_call(phram, phram_param_call, NULL, NULL, 000);
-MODULE_PARM_DESC(phram, Memory region to map.
\phram=name,start,length\);
+MODULE_PARM_DESC(phram, Memory region to map.
\phram=name,start,length[,erasesize]\);
static int __init init_phram(void)
--
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Re: [PATCH] phram: Allow the user to set the erase page size.
On Fri, 15 February 2013 12:35:46 -0800, Patrick O'Grady wrote: Permit the user to specify the erase page size as a parameter. This solves two problems: - phram can access images made by mkfs.jffs2. mkfs.jffs2 won't create images with erase sizes less than 8KiB; many architectures define PAGE_SIZE as 4KiB. - Allows more effective use of small capacity devices. JFFS2 needs somewhere between 2 and 5 empty pages for garbage collection; and for an NVRAM part with only 32KiB of space, a smaller erase page allows much better utilization in applications where garbage collection is important. Signed-off-by: Patrick O'Grady patr...@baymotion.com I can't see any argument against this. Reviewed-by: Joern Engel jo...@logfs.org Jörn -- [One] doesn't need to know [...] how to cause a headache in order to take an aspirin. -- Scott Culp, Manager of the Microsoft Security Response Center, 2001 -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
