From: Patrick O'Grady <[email protected]>
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 <[email protected]>
Reviewed-by: Joern Engel <[email protected]>
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 <[email protected]>
v3:
update authorship for Patrick O'Grady and remove the reported-by tag for kernel test robot
v2: https://lore.kernel.org/lkml/[email protected]/
fix build error which is reported by kernel test robot
v1: https://lore.kernel.org/lkml/[email protected]/
1.fix token array index out of bounds
2.update patch for kernel master branch
---
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=<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
+ * <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.
+ * 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
@@ -26,6 +26,7 @@
#include <linux/moduleparam.h>
#include <linux/slab.h>
#include <linux/mtd/mtd.h>
+#include <asm/div64.h>
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=<device>,<address>,<size> for module case
- * - phram.phram=<device>,<address>,<size> 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,0xa0000000,512Mi
+ * - 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, 20 for the address , 20 for the
+ * size and 20 for the erasesize.
+ * Example: phram.phram=rootfs,0xa0000000,512Mi,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(&str, ",");
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(&erasesize, 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=<name>,<start>,<length>\"");
+MODULE_PARM_DESC(phram, "Memory region to map. \"phram=<name>,<start>,<length>[,<erasesize>]\"");
static int __init init_phram(void)
--
2.12.3
Hi Guohua,
Guohua Zhong <[email protected]> wrote on Mon, 7 Dec 2020
16:53:42 +0800:
> From: Patrick O'Grady <[email protected]>
>
> 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 <[email protected]>
> Reviewed-by: Joern Engel <[email protected]>
> 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 <[email protected]>
>
> v3:
> update authorship for Patrick O'Grady and remove the reported-by tag for kernel test robot
>
> v2: https://lore.kernel.org/lkml/[email protected]/
> fix build error which is reported by kernel test robot
>
> v1: https://lore.kernel.org/lkml/[email protected]/
> 1.fix token array index out of bounds
> 2.update patch for kernel master branch
I cannot apply your patch as-is: the changelog (v1, v2, etc) should be
below the three dashes...
> ---
...here!
Otherwise it would be part of the final commit message, which is not
something we want.
> 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=<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
> + * <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.
> + * 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
> @@ -26,6 +26,7 @@
> #include <linux/moduleparam.h>
> #include <linux/slab.h>
> #include <linux/mtd/mtd.h>
> +#include <asm/div64.h>
>
> 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=<device>,<address>,<size> for module case
> - * - phram.phram=<device>,<address>,<size> 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,0xa0000000,512Mi
> + * - 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, 20 for the address , 20 for the
> + * size and 20 for the erasesize.
> + * Example: phram.phram=rootfs,0xa0000000,512Mi,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(&str, ",");
>
> 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(&erasesize, 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=<name>,<start>,<length>\"");
> +MODULE_PARM_DESC(phram, "Memory region to map. \"phram=<name>,<start>,<length>[,<erasesize>]\"");
>
>
> static int __init init_phram(void)
Thanks,
Miquèl