Re: [PATCH] mtd: add OTP (one-time-programmable) erase ioctl
Hello, Michael Walle wrote on Thu, 08 Apr 2021 08:55:42 +0200: > Hi Tudor, > > Am 2021-04-08 07:51, schrieb tudor.amba...@microchip.com: > > Would you please resend this patch, together with the mtd-utils > > and the SPI NOR patch in a single patch set? You'll help us all > > having all in a single place. > > This has already been picked-up: > https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git/commit/?h=mtd/next=e3c1f1c92d6ede3cfa09d6a103d3d1c1ef645e35 > > Although, I didn't receive an email notice. > > -michael Sometimes the notifications are not triggered when there is a conflict when applying the patch from patchwork directly. I usually answer manually in this case but I might have forgotten. About the patch, I felt it was good enough for merging, and I want to avoid applying such patches right before freezing our branches. Hence, I tend to be more aggressive earlier in the release cycles because I hate when my patches get delayed infinitely. The other side is a more careful approach when -rc6 gets tagged so that I can drop anything which would be crazily broken before our -next branches are stalled, leading for an useless public revert. Of course, I am fully open to removing this patch from -next if you ever feel it was too early and will happily get rid of it for this release: we can move the patch for the next release if you agree on this (especially since it touches the ABI). Cheers, Miquèl
Re: [PATCH] mtd: add OTP (one-time-programmable) erase ioctl
Hi Tudor, Am 2021-04-08 07:51, schrieb tudor.amba...@microchip.com: Would you please resend this patch, together with the mtd-utils and the SPI NOR patch in a single patch set? You'll help us all having all in a single place. This has already been picked-up: https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git/commit/?h=mtd/next=e3c1f1c92d6ede3cfa09d6a103d3d1c1ef645e35 Although, I didn't receive an email notice. -michael
Re: [PATCH] mtd: add OTP (one-time-programmable) erase ioctl
Michael, Would you please resend this patch, together with the mtd-utils and the SPI NOR patch in a single patch set? You'll help us all having all in a single place. For the new ioctl we'll need acks from all the mtd maintainers and at least a tested-by tag. Cheers, ta
Re: [PATCH] mtd: add OTP (one-time-programmable) erase ioctl
On 3/4/21 1:48 AM, Michael Walle wrote: > This may sound like a contradiction but some SPI-NOR flashes really > support erasing their OTP region until it is finally locked. Having the > possibility to erase an OTP region might come in handy during > development. > > The ioctl argument follows the OTPLOCK style. > > Signed-off-by: Michael Walle > --- Acked-by: Vignesh Raghavendra [...] Regards Vignesh
[PATCH] mtd: add OTP (one-time-programmable) erase ioctl
This may sound like a contradiction but some SPI-NOR flashes really
support erasing their OTP region until it is finally locked. Having the
possibility to erase an OTP region might come in handy during
development.
The ioctl argument follows the OTPLOCK style.
Signed-off-by: Michael Walle
---
Changes since RFC:
- check write permissions for OTPERASE
- use correct ioctl macro (_IOW)
drivers/mtd/mtdchar.c | 7 ++-
drivers/mtd/mtdcore.c | 12
include/linux/mtd/mtd.h| 3 +++
include/uapi/mtd/mtd-abi.h | 2 ++
4 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index 57c4a2f0b703..b9b56eb9457e 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -666,6 +666,7 @@ static int mtdchar_ioctl(struct file *file, u_int cmd,
u_long arg)
case MEMWRITEOOB:
case MEMWRITEOOB64:
case MEMWRITE:
+ case OTPERASE:
if (!(file->f_mode & FMODE_WRITE))
return -EPERM;
break;
@@ -930,6 +931,7 @@ static int mtdchar_ioctl(struct file *file, u_int cmd,
u_long arg)
}
case OTPLOCK:
+ case OTPERASE:
{
struct otp_info oinfo;
@@ -937,7 +939,10 @@ static int mtdchar_ioctl(struct file *file, u_int cmd,
u_long arg)
return -EINVAL;
if (copy_from_user(, argp, sizeof(oinfo)))
return -EFAULT;
- ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
+ if (cmd == OTPLOCK)
+ ret = mtd_lock_user_prot_reg(mtd, oinfo.start,
oinfo.length);
+ else
+ ret = mtd_erase_user_prot_reg(mtd, oinfo.start,
oinfo.length);
break;
}
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 38782ceea1f6..aea58366a94e 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -1919,6 +1919,18 @@ int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t
from, size_t len)
}
EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
+int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
+{
+ struct mtd_info *master = mtd_get_master(mtd);
+
+ if (!master->_erase_user_prot_reg)
+ return -EOPNOTSUPP;
+ if (!len)
+ return 0;
+ return master->_erase_user_prot_reg(master, from, len);
+}
+EXPORT_SYMBOL_GPL(mtd_erase_user_prot_reg);
+
/* Chip-supported device locking */
int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index ceabc2cae8a4..4aac200ca8b5 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -337,6 +337,8 @@ struct mtd_info {
size_t len, size_t *retlen, u_char *buf);
int (*_lock_user_prot_reg) (struct mtd_info *mtd, loff_t from,
size_t len);
+ int (*_erase_user_prot_reg) (struct mtd_info *mtd, loff_t from,
+size_t len);
int (*_writev) (struct mtd_info *mtd, const struct kvec *vecs,
unsigned long count, loff_t to, size_t *retlen);
void (*_sync) (struct mtd_info *mtd);
@@ -518,6 +520,7 @@ int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t
from, size_t len,
int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
size_t *retlen, u_char *buf);
int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len);
+int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len);
int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
unsigned long count, loff_t to, size_t *retlen);
diff --git a/include/uapi/mtd/mtd-abi.h b/include/uapi/mtd/mtd-abi.h
index 65b9db936557..b869990c2db2 100644
--- a/include/uapi/mtd/mtd-abi.h
+++ b/include/uapi/mtd/mtd-abi.h
@@ -205,6 +205,8 @@ struct otp_info {
* without OOB, e.g., NOR flash.
*/
#define MEMWRITE _IOWR('M', 24, struct mtd_write_req)
+/* Erase a given range of user data (must be in mode %MTD_FILE_MODE_OTP_USER)
*/
+#define OTPERASE _IOW('M', 25, struct otp_info)
/*
* Obsolete legacy interface. Keep it in order not to break userspace
--
2.20.1
Re: [RFC PATCH] mtd: add OTP (one-time-programmable) erase ioctl
On 3/2/21 9:49 PM, Michael Walle wrote:
> Am 2021-03-02 16:30, schrieb Vignesh Raghavendra:
>> Hi,
>>
>> On 3/2/21 4:39 PM, Michael Walle wrote:
>>> This may sound like a contradiction but some SPI-NOR flashes really
>>> support erasing their OTP region until it is finally locked. Having the
>>> possibility to erase an OTP region might come in handy during
>>> development.
>>>
>>> The ioctl argument follows the OTPLOCK style.
>>>
>>> Signed-off-by: Michael Walle
>>> ---
>>> OTP support for SPI-NOR flashes may be merged soon:
>>> https://lore.kernel.org/linux-mtd/20210216162807.13509-1-mich...@walle.cc/
>>>
>>>
>>> Tudor suggested to add support for the OTP erase operation most SPI-NOR
>>> flashes have:
>>> https://lore.kernel.org/linux-mtd/d4f74b1b-fa1b-97ec-858c-d807fe1f9...@microchip.com/
>>>
>>>
>>> Therefore, this is an RFC to get some feedback on the MTD side, once
>>> this
>>> is finished, I can post a patch for mtd-utils. Then we'll have a
>>> foundation
>>> to add the support to SPI-NOR.
>>>
>>> drivers/mtd/mtdchar.c | 7 ++-
>>> drivers/mtd/mtdcore.c | 12
>>> include/linux/mtd/mtd.h | 3 +++
>>> include/uapi/mtd/mtd-abi.h | 2 ++
>>> 4 files changed, 23 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
>>> index 323035d4f2d0..da423dd031ae 100644
>>> --- a/drivers/mtd/mtdchar.c
>>> +++ b/drivers/mtd/mtdchar.c
>>> @@ -661,6 +661,7 @@ static int mtdchar_ioctl(struct file *file, u_int
>>> cmd, u_long arg)
>>> case OTPGETREGIONCOUNT:
>>> case OTPGETREGIONINFO:
>>> case OTPLOCK:
>>> + case OTPERASE:
>>
>> This is not a Safe IOCTL. We are destroying OTP data. Need to check for
>> write permission before allowing the ioctl right?
>
> Ah yes, of course. But this makes me wonder why OTPLOCK
> is considered a safe command. As well as MEMLOCK and
> MEMUNLOCK. And MEMSETBADBLOCK. Shouldn't these also
> require write permissions?
>
Well, one argument would be that LOCK/UNLOCK in itself won't modify data
and thus does not need write permission.. Although can brick a flash
from ever being writable again and change content of flash registers.
I am fine with moving these to require write permissions as well
(probably OTPLOCK as well).
[...]
>>> diff --git a/include/uapi/mtd/mtd-abi.h b/include/uapi/mtd/mtd-abi.h
>>> index 65b9db936557..242015f60d10 100644
>>> --- a/include/uapi/mtd/mtd-abi.h
>>> +++ b/include/uapi/mtd/mtd-abi.h
>>> @@ -205,6 +205,8 @@ struct otp_info {
>>> * without OOB, e.g., NOR flash.
>>> */
>>> #define MEMWRITE _IOWR('M', 24, struct mtd_write_req)
>>> +/* Erase a given range of user data (must be in mode
>>> %MTD_FILE_MODE_OTP_USER) */
>>> +#define OTPERASE _IOR('M', 25, struct otp_info)
>>>
>>
>> Hmm, shouldn't this be:
>>
>> #define OTPERASE _IOW('M', 25, struct otp_info)
>>
>> Userspace is writing struct otp_info to the driver. OTPLOCK should
>> probably be _IOW() as well.
>
> You're right.
>
> NB. most OTP commands have a wrong direction flag.
>
Unfortunately, yes :(
Regards
Vignesh
Re: [RFC PATCH] mtd: add OTP (one-time-programmable) erase ioctl
Am 2021-03-02 17:33, schrieb Vignesh Raghavendra: On 3/2/21 9:49 PM, Michael Walle wrote: Am 2021-03-02 16:30, schrieb Vignesh Raghavendra: Hi, On 3/2/21 4:39 PM, Michael Walle wrote: This may sound like a contradiction but some SPI-NOR flashes really support erasing their OTP region until it is finally locked. Having the possibility to erase an OTP region might come in handy during development. The ioctl argument follows the OTPLOCK style. Signed-off-by: Michael Walle --- OTP support for SPI-NOR flashes may be merged soon: https://lore.kernel.org/linux-mtd/20210216162807.13509-1-mich...@walle.cc/ Tudor suggested to add support for the OTP erase operation most SPI-NOR flashes have: https://lore.kernel.org/linux-mtd/d4f74b1b-fa1b-97ec-858c-d807fe1f9...@microchip.com/ Therefore, this is an RFC to get some feedback on the MTD side, once this is finished, I can post a patch for mtd-utils. Then we'll have a foundation to add the support to SPI-NOR. drivers/mtd/mtdchar.c | 7 ++- drivers/mtd/mtdcore.c | 12 include/linux/mtd/mtd.h | 3 +++ include/uapi/mtd/mtd-abi.h | 2 ++ 4 files changed, 23 insertions(+), 1 deletion(-) diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c index 323035d4f2d0..da423dd031ae 100644 --- a/drivers/mtd/mtdchar.c +++ b/drivers/mtd/mtdchar.c @@ -661,6 +661,7 @@ static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg) case OTPGETREGIONCOUNT: case OTPGETREGIONINFO: case OTPLOCK: + case OTPERASE: This is not a Safe IOCTL. We are destroying OTP data. Need to check for write permission before allowing the ioctl right? Ah yes, of course. But this makes me wonder why OTPLOCK is considered a safe command. As well as MEMLOCK and MEMUNLOCK. And MEMSETBADBLOCK. Shouldn't these also require write permissions? Well, one argument would be that LOCK/UNLOCK in itself won't modify data and thus does not need write permission.. Although can brick a flash from ever being writable again and change content of flash registers. Whether not you can brick a device (I agree with you), it is writing to the protection bits. But what is more imporant is that OTPLOCK is actually write-once. I am fine with moving these to require write permissions as well (probably OTPLOCK as well). Ok, I'm unsure about MEMSETBADBLOCK, though. -michael
Re: [RFC PATCH] mtd: add OTP (one-time-programmable) erase ioctl
Am 2021-03-02 16:30, schrieb Vignesh Raghavendra:
Hi,
On 3/2/21 4:39 PM, Michael Walle wrote:
This may sound like a contradiction but some SPI-NOR flashes really
support erasing their OTP region until it is finally locked. Having
the
possibility to erase an OTP region might come in handy during
development.
The ioctl argument follows the OTPLOCK style.
Signed-off-by: Michael Walle
---
OTP support for SPI-NOR flashes may be merged soon:
https://lore.kernel.org/linux-mtd/20210216162807.13509-1-mich...@walle.cc/
Tudor suggested to add support for the OTP erase operation most
SPI-NOR
flashes have:
https://lore.kernel.org/linux-mtd/d4f74b1b-fa1b-97ec-858c-d807fe1f9...@microchip.com/
Therefore, this is an RFC to get some feedback on the MTD side, once
this
is finished, I can post a patch for mtd-utils. Then we'll have a
foundation
to add the support to SPI-NOR.
drivers/mtd/mtdchar.c | 7 ++-
drivers/mtd/mtdcore.c | 12
include/linux/mtd/mtd.h| 3 +++
include/uapi/mtd/mtd-abi.h | 2 ++
4 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index 323035d4f2d0..da423dd031ae 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -661,6 +661,7 @@ static int mtdchar_ioctl(struct file *file, u_int
cmd, u_long arg)
case OTPGETREGIONCOUNT:
case OTPGETREGIONINFO:
case OTPLOCK:
+ case OTPERASE:
This is not a Safe IOCTL. We are destroying OTP data. Need to check for
write permission before allowing the ioctl right?
Ah yes, of course. But this makes me wonder why OTPLOCK
is considered a safe command. As well as MEMLOCK and
MEMUNLOCK. And MEMSETBADBLOCK. Shouldn't these also
require write permissions?
case ECCGETLAYOUT:
case ECCGETSTATS:
case MTDFILEMODE:
@@ -938,6 +939,7 @@ static int mtdchar_ioctl(struct file *file, u_int
cmd, u_long arg)
}
case OTPLOCK:
+ case OTPERASE:
{
struct otp_info oinfo;
@@ -945,7 +947,10 @@ static int mtdchar_ioctl(struct file *file, u_int
cmd, u_long arg)
return -EINVAL;
if (copy_from_user(, argp, sizeof(oinfo)))
return -EFAULT;
- ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
+ if (cmd == OTPLOCK)
+ ret = mtd_lock_user_prot_reg(mtd, oinfo.start,
oinfo.length);
+ else
+ ret = mtd_erase_user_prot_reg(mtd, oinfo.start,
oinfo.length);
break;
}
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 2d6423d89a17..d844d718ef77 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -1918,6 +1918,18 @@ int mtd_lock_user_prot_reg(struct mtd_info
*mtd, loff_t from, size_t len)
}
EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
+int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t
len)
+{
+ struct mtd_info *master = mtd_get_master(mtd);
+
+ if (!master->_erase_user_prot_reg)
+ return -EOPNOTSUPP;
+ if (!len)
+ return 0;
+ return master->_erase_user_prot_reg(master, from, len);
+}
+EXPORT_SYMBOL_GPL(mtd_erase_user_prot_reg);
+
/* Chip-supported device locking */
int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index 157357ec1441..734ad7a8c353 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -336,6 +336,8 @@ struct mtd_info {
size_t len, size_t *retlen, u_char *buf);
int (*_lock_user_prot_reg) (struct mtd_info *mtd, loff_t from,
size_t len);
+ int (*_erase_user_prot_reg) (struct mtd_info *mtd, loff_t from,
+size_t len);
int (*_writev) (struct mtd_info *mtd, const struct kvec *vecs,
unsigned long count, loff_t to, size_t *retlen);
void (*_sync) (struct mtd_info *mtd);
@@ -517,6 +519,7 @@ int mtd_read_user_prot_reg(struct mtd_info *mtd,
loff_t from, size_t len,
int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t
len,
size_t *retlen, u_char *buf);
int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t
len);
+int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t
len);
int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
unsigned long count, loff_t to, size_t *retlen);
diff --git a/include/uapi/mtd/mtd-abi.h b/include/uapi/mtd/mtd-abi.h
index 65b9db936557..242015f60d10 100644
--- a/include/uapi/mtd/mtd-abi.h
+++ b/include/uapi/mtd/mtd-abi.h
@@ -205,6 +205,8 @@ struct otp_info {
* without OOB, e.g., NOR flash.
*/
#define MEMWRITE _IOWR('M', 24, struct mtd_write_req)
+/* Erase a given range of user data (must be in mode
Re: [RFC PATCH] mtd: add OTP (one-time-programmable) erase ioctl
Hi,
On 3/2/21 4:39 PM, Michael Walle wrote:
> This may sound like a contradiction but some SPI-NOR flashes really
> support erasing their OTP region until it is finally locked. Having the
> possibility to erase an OTP region might come in handy during
> development.
>
> The ioctl argument follows the OTPLOCK style.
>
> Signed-off-by: Michael Walle
> ---
> OTP support for SPI-NOR flashes may be merged soon:
> https://lore.kernel.org/linux-mtd/20210216162807.13509-1-mich...@walle.cc/
>
> Tudor suggested to add support for the OTP erase operation most SPI-NOR
> flashes have:
> https://lore.kernel.org/linux-mtd/d4f74b1b-fa1b-97ec-858c-d807fe1f9...@microchip.com/
>
> Therefore, this is an RFC to get some feedback on the MTD side, once this
> is finished, I can post a patch for mtd-utils. Then we'll have a foundation
> to add the support to SPI-NOR.
>
> drivers/mtd/mtdchar.c | 7 ++-
> drivers/mtd/mtdcore.c | 12
> include/linux/mtd/mtd.h| 3 +++
> include/uapi/mtd/mtd-abi.h | 2 ++
> 4 files changed, 23 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
> index 323035d4f2d0..da423dd031ae 100644
> --- a/drivers/mtd/mtdchar.c
> +++ b/drivers/mtd/mtdchar.c
> @@ -661,6 +661,7 @@ static int mtdchar_ioctl(struct file *file, u_int cmd,
> u_long arg)
> case OTPGETREGIONCOUNT:
> case OTPGETREGIONINFO:
> case OTPLOCK:
> + case OTPERASE:
This is not a Safe IOCTL. We are destroying OTP data. Need to check for
write permission before allowing the ioctl right?
> case ECCGETLAYOUT:
> case ECCGETSTATS:
> case MTDFILEMODE:
> @@ -938,6 +939,7 @@ static int mtdchar_ioctl(struct file *file, u_int cmd,
> u_long arg)
> }
>
> case OTPLOCK:
> + case OTPERASE:
> {
> struct otp_info oinfo;
>
> @@ -945,7 +947,10 @@ static int mtdchar_ioctl(struct file *file, u_int cmd,
> u_long arg)
> return -EINVAL;
> if (copy_from_user(, argp, sizeof(oinfo)))
> return -EFAULT;
> - ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
> + if (cmd == OTPLOCK)
> + ret = mtd_lock_user_prot_reg(mtd, oinfo.start,
> oinfo.length);
> + else
> + ret = mtd_erase_user_prot_reg(mtd, oinfo.start,
> oinfo.length);
> break;
> }
>
> diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
> index 2d6423d89a17..d844d718ef77 100644
> --- a/drivers/mtd/mtdcore.c
> +++ b/drivers/mtd/mtdcore.c
> @@ -1918,6 +1918,18 @@ int mtd_lock_user_prot_reg(struct mtd_info *mtd,
> loff_t from, size_t len)
> }
> EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
>
> +int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
> +{
> + struct mtd_info *master = mtd_get_master(mtd);
> +
> + if (!master->_erase_user_prot_reg)
> + return -EOPNOTSUPP;
> + if (!len)
> + return 0;
> + return master->_erase_user_prot_reg(master, from, len);
> +}
> +EXPORT_SYMBOL_GPL(mtd_erase_user_prot_reg);
> +
> /* Chip-supported device locking */
> int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
> {
> diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
> index 157357ec1441..734ad7a8c353 100644
> --- a/include/linux/mtd/mtd.h
> +++ b/include/linux/mtd/mtd.h
> @@ -336,6 +336,8 @@ struct mtd_info {
>size_t len, size_t *retlen, u_char *buf);
> int (*_lock_user_prot_reg) (struct mtd_info *mtd, loff_t from,
> size_t len);
> + int (*_erase_user_prot_reg) (struct mtd_info *mtd, loff_t from,
> + size_t len);
> int (*_writev) (struct mtd_info *mtd, const struct kvec *vecs,
> unsigned long count, loff_t to, size_t *retlen);
> void (*_sync) (struct mtd_info *mtd);
> @@ -517,6 +519,7 @@ int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t
> from, size_t len,
> int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
> size_t *retlen, u_char *buf);
> int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len);
> +int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len);
>
> int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
> unsigned long count, loff_t to, size_t *retlen);
> diff --git a/include/uapi/mtd/mtd-abi.h b/include/uapi/mtd/mtd-abi.h
> index 65b9db936557..242015f60d10 100644
> --- a/include/uapi/mtd/mtd-abi.h
> +++ b/include/uapi/mtd/mtd-abi.h
> @@ -205,6 +205,8 @@ struct otp_info {
> * without OOB, e.g., NOR flash.
> */
> #define MEMWRITE _IOWR('M', 24, struct mtd_write_req)
> +/* Erase a given range of user data (must be in mode
> %MTD_FILE_MODE_OTP_USER) */
> +#define OTPERASE _IOR('M', 25, struct otp_info)
>
Hmm,
Re: [RFC PATCH] mtd: add OTP (one-time-programmable) erase ioctl
Hi,
Am 2021-03-02 13:46, schrieb Miquel Raynal:
Michael Walle wrote on Tue, 2 Mar 2021 12:09:27
+0100:
This may sound like a contradiction but some SPI-NOR flashes really
support erasing their OTP region until it is finally locked. Having
the
possibility to erase an OTP region might come in handy during
development.
The ioctl argument follows the OTPLOCK style.
Signed-off-by: Michael Walle
---
OTP support for SPI-NOR flashes may be merged soon:
https://lore.kernel.org/linux-mtd/20210216162807.13509-1-mich...@walle.cc/
Tudor suggested to add support for the OTP erase operation most
SPI-NOR
flashes have:
https://lore.kernel.org/linux-mtd/d4f74b1b-fa1b-97ec-858c-d807fe1f9...@microchip.com/
Therefore, this is an RFC to get some feedback on the MTD side, once
this
is finished, I can post a patch for mtd-utils. Then we'll have a
foundation
to add the support to SPI-NOR.
[..]
+int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t
len)
+{
+ struct mtd_info *master = mtd_get_master(mtd);
+
+ if (!master->_erase_user_prot_reg)
+ return -EOPNOTSUPP;
+ if (!len)
+ return 0;
Should we add a sanity check enforcing that we don't try to access
beyond the end of the OTP area?
This is checked in the op itself, as it is done for all the
other OTP read/write/lock ops.
Right at the moment, I don't see how this could be achieved in
an elegant way. Without additional changes, you'd have to call
mtd_get_user_prot_info() and iterate over the returned values
and figure out whether from and len are valid.
[..]
-michael
Re: [RFC PATCH] mtd: add OTP (one-time-programmable) erase ioctl
Hi Michael,
Michael Walle wrote on Tue, 2 Mar 2021 12:09:27
+0100:
> This may sound like a contradiction but some SPI-NOR flashes really
> support erasing their OTP region until it is finally locked. Having the
> possibility to erase an OTP region might come in handy during
> development.
>
> The ioctl argument follows the OTPLOCK style.
>
> Signed-off-by: Michael Walle
> ---
> OTP support for SPI-NOR flashes may be merged soon:
> https://lore.kernel.org/linux-mtd/20210216162807.13509-1-mich...@walle.cc/
>
> Tudor suggested to add support for the OTP erase operation most SPI-NOR
> flashes have:
> https://lore.kernel.org/linux-mtd/d4f74b1b-fa1b-97ec-858c-d807fe1f9...@microchip.com/
>
> Therefore, this is an RFC to get some feedback on the MTD side, once this
> is finished, I can post a patch for mtd-utils. Then we'll have a foundation
> to add the support to SPI-NOR.
>
> drivers/mtd/mtdchar.c | 7 ++-
> drivers/mtd/mtdcore.c | 12
> include/linux/mtd/mtd.h| 3 +++
> include/uapi/mtd/mtd-abi.h | 2 ++
> 4 files changed, 23 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
> index 323035d4f2d0..da423dd031ae 100644
> --- a/drivers/mtd/mtdchar.c
> +++ b/drivers/mtd/mtdchar.c
> @@ -661,6 +661,7 @@ static int mtdchar_ioctl(struct file *file, u_int cmd,
> u_long arg)
> case OTPGETREGIONCOUNT:
> case OTPGETREGIONINFO:
> case OTPLOCK:
> + case OTPERASE:
> case ECCGETLAYOUT:
> case ECCGETSTATS:
> case MTDFILEMODE:
> @@ -938,6 +939,7 @@ static int mtdchar_ioctl(struct file *file, u_int cmd,
> u_long arg)
> }
>
> case OTPLOCK:
> + case OTPERASE:
> {
> struct otp_info oinfo;
>
> @@ -945,7 +947,10 @@ static int mtdchar_ioctl(struct file *file, u_int cmd,
> u_long arg)
> return -EINVAL;
> if (copy_from_user(, argp, sizeof(oinfo)))
> return -EFAULT;
> - ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
> + if (cmd == OTPLOCK)
> + ret = mtd_lock_user_prot_reg(mtd, oinfo.start,
> oinfo.length);
> + else
> + ret = mtd_erase_user_prot_reg(mtd, oinfo.start,
> oinfo.length);
> break;
> }
>
> diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
> index 2d6423d89a17..d844d718ef77 100644
> --- a/drivers/mtd/mtdcore.c
> +++ b/drivers/mtd/mtdcore.c
> @@ -1918,6 +1918,18 @@ int mtd_lock_user_prot_reg(struct mtd_info *mtd,
> loff_t from, size_t len)
> }
> EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
>
> +int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
> +{
> + struct mtd_info *master = mtd_get_master(mtd);
> +
> + if (!master->_erase_user_prot_reg)
> + return -EOPNOTSUPP;
> + if (!len)
> + return 0;
Should we add a sanity check enforcing that we don't try to access
beyond the end of the OTP area?
> + return master->_erase_user_prot_reg(master, from, len);
> +}
> +EXPORT_SYMBOL_GPL(mtd_erase_user_prot_reg);
> +
> /* Chip-supported device locking */
> int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
> {
> diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
> index 157357ec1441..734ad7a8c353 100644
> --- a/include/linux/mtd/mtd.h
> +++ b/include/linux/mtd/mtd.h
> @@ -336,6 +336,8 @@ struct mtd_info {
>size_t len, size_t *retlen, u_char *buf);
> int (*_lock_user_prot_reg) (struct mtd_info *mtd, loff_t from,
> size_t len);
> + int (*_erase_user_prot_reg) (struct mtd_info *mtd, loff_t from,
> + size_t len);
> int (*_writev) (struct mtd_info *mtd, const struct kvec *vecs,
> unsigned long count, loff_t to, size_t *retlen);
> void (*_sync) (struct mtd_info *mtd);
> @@ -517,6 +519,7 @@ int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t
> from, size_t len,
> int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
> size_t *retlen, u_char *buf);
> int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len);
> +int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len);
>
> int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
> unsigned long count, loff_t to, size_t *retlen);
> diff --git a/include/uapi/mtd/mtd-abi.h b/include/uapi/mtd/mtd-abi.h
> index 65b9db936557..242015f60d10 100644
> --- a/include/uapi/mtd/mtd-abi.h
> +++ b/include/uapi/mtd/mtd-abi.h
> @@ -205,6 +205,8 @@ struct otp_info {
> * without OOB, e.g., NOR flash.
> */
> #define MEMWRITE _IOWR('M', 24, struct mtd_write_req)
> +/* Erase a given range of user data (must be in mode
> %MTD_FILE_MODE_OTP_USER) */
> +#define OTPERASE _IOR('M', 25, struct otp_info)
>
> /*
>
[RFC PATCH] mtd: add OTP (one-time-programmable) erase ioctl
This may sound like a contradiction but some SPI-NOR flashes really
support erasing their OTP region until it is finally locked. Having the
possibility to erase an OTP region might come in handy during
development.
The ioctl argument follows the OTPLOCK style.
Signed-off-by: Michael Walle
---
OTP support for SPI-NOR flashes may be merged soon:
https://lore.kernel.org/linux-mtd/20210216162807.13509-1-mich...@walle.cc/
Tudor suggested to add support for the OTP erase operation most SPI-NOR
flashes have:
https://lore.kernel.org/linux-mtd/d4f74b1b-fa1b-97ec-858c-d807fe1f9...@microchip.com/
Therefore, this is an RFC to get some feedback on the MTD side, once this
is finished, I can post a patch for mtd-utils. Then we'll have a foundation
to add the support to SPI-NOR.
drivers/mtd/mtdchar.c | 7 ++-
drivers/mtd/mtdcore.c | 12
include/linux/mtd/mtd.h| 3 +++
include/uapi/mtd/mtd-abi.h | 2 ++
4 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index 323035d4f2d0..da423dd031ae 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -661,6 +661,7 @@ static int mtdchar_ioctl(struct file *file, u_int cmd,
u_long arg)
case OTPGETREGIONCOUNT:
case OTPGETREGIONINFO:
case OTPLOCK:
+ case OTPERASE:
case ECCGETLAYOUT:
case ECCGETSTATS:
case MTDFILEMODE:
@@ -938,6 +939,7 @@ static int mtdchar_ioctl(struct file *file, u_int cmd,
u_long arg)
}
case OTPLOCK:
+ case OTPERASE:
{
struct otp_info oinfo;
@@ -945,7 +947,10 @@ static int mtdchar_ioctl(struct file *file, u_int cmd,
u_long arg)
return -EINVAL;
if (copy_from_user(, argp, sizeof(oinfo)))
return -EFAULT;
- ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
+ if (cmd == OTPLOCK)
+ ret = mtd_lock_user_prot_reg(mtd, oinfo.start,
oinfo.length);
+ else
+ ret = mtd_erase_user_prot_reg(mtd, oinfo.start,
oinfo.length);
break;
}
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 2d6423d89a17..d844d718ef77 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -1918,6 +1918,18 @@ int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t
from, size_t len)
}
EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
+int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
+{
+ struct mtd_info *master = mtd_get_master(mtd);
+
+ if (!master->_erase_user_prot_reg)
+ return -EOPNOTSUPP;
+ if (!len)
+ return 0;
+ return master->_erase_user_prot_reg(master, from, len);
+}
+EXPORT_SYMBOL_GPL(mtd_erase_user_prot_reg);
+
/* Chip-supported device locking */
int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index 157357ec1441..734ad7a8c353 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -336,6 +336,8 @@ struct mtd_info {
size_t len, size_t *retlen, u_char *buf);
int (*_lock_user_prot_reg) (struct mtd_info *mtd, loff_t from,
size_t len);
+ int (*_erase_user_prot_reg) (struct mtd_info *mtd, loff_t from,
+size_t len);
int (*_writev) (struct mtd_info *mtd, const struct kvec *vecs,
unsigned long count, loff_t to, size_t *retlen);
void (*_sync) (struct mtd_info *mtd);
@@ -517,6 +519,7 @@ int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t
from, size_t len,
int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
size_t *retlen, u_char *buf);
int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len);
+int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len);
int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
unsigned long count, loff_t to, size_t *retlen);
diff --git a/include/uapi/mtd/mtd-abi.h b/include/uapi/mtd/mtd-abi.h
index 65b9db936557..242015f60d10 100644
--- a/include/uapi/mtd/mtd-abi.h
+++ b/include/uapi/mtd/mtd-abi.h
@@ -205,6 +205,8 @@ struct otp_info {
* without OOB, e.g., NOR flash.
*/
#define MEMWRITE _IOWR('M', 24, struct mtd_write_req)
+/* Erase a given range of user data (must be in mode %MTD_FILE_MODE_OTP_USER)
*/
+#define OTPERASE _IOR('M', 25, struct otp_info)
/*
* Obsolete legacy interface. Keep it in order not to break userspace
--
2.20.1
