* [PATCH v4] mtd: gpmi: add NAND write verify support
@ 2012-08-12 2:07 Huang Shijie
2012-08-11 14:10 ` Marek Vasut
0 siblings, 1 reply; 6+ messages in thread
From: Huang Shijie @ 2012-08-12 2:07 UTC (permalink / raw)
To: linux-arm-kernel
Add NAND write verify support in gpmi-nand driver.
This patch fixes a kernel crash when we select
CONFIG_MTD_NAND_VERIFY_WRITE=y, and do some write tests:
root at freescale /$ dd if=/dev/zero of=/dev/mtd0 bs=128k count=1
[ 41.070000] Unable to handle kernel NULL pointer dereference at virtual addr0
[ 41.080000] pgd = c77ac000
[ 41.080000] [00000000] *pgd=4773c831, *pte=00000000, *ppte=00000000
[ 41.090000] Internal error: Oops: 17 [#1] ARM
[ 41.090000] Modules linked in:
[ 41.090000] CPU: 0 Not tainted (3.6.0-rc1-next-20120809-00002-ga25d017-d)
[ 41.090000] PC is at nand_verify_buf+0x18/0x5c
[ 41.090000] LR is at nand_write_page+0xc0/0x140
[ 41.090000] pc : [<c023e7d4>] lr : [<c023fcfc>] psr: 20000013
[ 41.090000] sp : c7779de4 ip : 00000000 fp : c6e60000
[ 41.090000] r10: 00000000 r9 : 00020000 r8 : 00000000
[ 41.090000] r7 : 00000000 r6 : c6e60000 r5 : c762cb10 r4 : 00000000
[ 41.090000] r3 : c762c8a8 r2 : 00000800 r1 : c6e60000 r0 : 00000000
[ 41.090000] Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user
[ 41.090000] Control: 0005317f Table: 477ac000 DAC: 00000015
[ 41.090000] Process dd (pid: 427, stack limit = 0xc7778270)
[ 41.090000] Stack: (0xc7779de4 to 0xc777a000)
...
The crash log is fetched from Fabio's patch. thanks to Fabio's hard work.
Cc: <stable@vger.kernel.org>
Reported-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Huang Shijie <shijie8@gmail.com>
---
v3 --> v4:
[1] add credit to Fabio.
v2 --> v3:
[1] free the verify_buf when we exit.
v1 --> v2:
[1] use the mtd->writesize to allocate the verify buffer.
[2] add new field `verify_buf` in gpmi_nand_data{}
tested this patch on imx6q-arm2 board.
---
drivers/mtd/nand/gpmi-nand/gpmi-nand.c | 25 +++++++++++++++++++++++++
drivers/mtd/nand/gpmi-nand/gpmi-nand.h | 1 +
2 files changed, 26 insertions(+), 0 deletions(-)
diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
index 8c0d2f0..e1e4c51 100644
--- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
+++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
@@ -1512,12 +1512,34 @@ static int gpmi_pre_bbt_scan(struct gpmi_nand_data *this)
return nand_boot_init(this);
}
+static int gpmi_verify_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
+{
+ struct nand_chip *chip = mtd->priv;
+ struct gpmi_nand_data *this = chip->priv;
+ int ret;
+
+ ret = chip->ecc.read_page(mtd, chip, this->verify_buf, 0, 0);
+ if (ret)
+ return -EFAULT;
+ if (memcmp(buf, this->verify_buf, len))
+ return -EFAULT;
+ return 0;
+}
+
static int gpmi_scan_bbt(struct mtd_info *mtd)
{
struct nand_chip *chip = mtd->priv;
struct gpmi_nand_data *this = chip->priv;
int ret;
+ /*
+ * We have gotten the right page size now, use it to allocate
+ * the proper verify buffer.
+ */
+ this->verify_buf = kzalloc(mtd->writesize, GFP_KERNEL);
+ if (!this->verify_buf)
+ return -ENOMEM;
+
/* Prepare for the BBT scan. */
ret = gpmi_pre_bbt_scan(this);
if (ret)
@@ -1531,6 +1553,8 @@ void gpmi_nfc_exit(struct gpmi_nand_data *this)
{
nand_release(&this->mtd);
gpmi_free_dma_buffer(this);
+ kfree(this->verify_buf);
+ this->verify_buf = NULL;
}
static int __devinit gpmi_nfc_init(struct gpmi_nand_data *this)
@@ -1556,6 +1580,7 @@ static int __devinit gpmi_nfc_init(struct gpmi_nand_data *this)
chip->read_byte = gpmi_read_byte;
chip->read_buf = gpmi_read_buf;
chip->write_buf = gpmi_write_buf;
+ chip->verify_buf = gpmi_verify_buf;
chip->ecc.read_page = gpmi_ecc_read_page;
chip->ecc.write_page = gpmi_ecc_write_page;
chip->ecc.read_oob = gpmi_ecc_read_oob;
diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.h b/drivers/mtd/nand/gpmi-nand/gpmi-nand.h
index 1547a60..8ddf115 100644
--- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.h
+++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.h
@@ -144,6 +144,7 @@ struct gpmi_nand_data {
/* MTD / NAND */
struct nand_chip nand;
struct mtd_info mtd;
+ uint8_t *verify_buf;
/* General-use Variables */
int current_chip;
--
1.7.4.4
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v4] mtd: gpmi: add NAND write verify support
2012-08-12 2:07 [PATCH v4] mtd: gpmi: add NAND write verify support Huang Shijie
@ 2012-08-11 14:10 ` Marek Vasut
2012-08-11 15:15 ` Huang Shijie
0 siblings, 1 reply; 6+ messages in thread
From: Marek Vasut @ 2012-08-11 14:10 UTC (permalink / raw)
To: linux-arm-kernel
Dear Huang Shijie,
> Add NAND write verify support in gpmi-nand driver.
>
> This patch fixes a kernel crash when we select
> CONFIG_MTD_NAND_VERIFY_WRITE=y, and do some write tests:
>
> root at freescale /$ dd if=/dev/zero of=/dev/mtd0 bs=128k count=1
> [ 41.070000] Unable to handle kernel NULL pointer dereference at virtual
> addr0 [ 41.080000] pgd = c77ac000
> [ 41.080000] [00000000] *pgd=4773c831, *pte=00000000, *ppte=00000000
> [ 41.090000] Internal error: Oops: 17 [#1] ARM
> [ 41.090000] Modules linked in:
> [ 41.090000] CPU: 0 Not tainted
> (3.6.0-rc1-next-20120809-00002-ga25d017-d) [ 41.090000] PC is at
> nand_verify_buf+0x18/0x5c
> [ 41.090000] LR is at nand_write_page+0xc0/0x140
> [ 41.090000] pc : [<c023e7d4>] lr : [<c023fcfc>] psr: 20000013
> [ 41.090000] sp : c7779de4 ip : 00000000 fp : c6e60000
> [ 41.090000] r10: 00000000 r9 : 00020000 r8 : 00000000
> [ 41.090000] r7 : 00000000 r6 : c6e60000 r5 : c762cb10 r4 : 00000000
> [ 41.090000] r3 : c762c8a8 r2 : 00000800 r1 : c6e60000 r0 : 00000000
> [ 41.090000] Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment
> user [ 41.090000] Control: 0005317f Table: 477ac000 DAC: 00000015
> [ 41.090000] Process dd (pid: 427, stack limit = 0xc7778270)
> [ 41.090000] Stack: (0xc7779de4 to 0xc777a000)
> ...
>
> The crash log is fetched from Fabio's patch. thanks to Fabio's hard
work.
>
> Cc: <stable@vger.kernel.org>
> Reported-by: Fabio Estevam <fabio.estevam@freescale.com>
> Signed-off-by: Huang Shijie <shijie8@gmail.com>
> ---
> v3 --> v4:
> [1] add credit to Fabio.
>
> v2 --> v3:
> [1] free the verify_buf when we exit.
>
> v1 --> v2:
> [1] use the mtd->writesize to allocate the verify buffer.
> [2] add new field `verify_buf` in gpmi_nand_data{}
>
> tested this patch on imx6q-arm2 board.
> ---
> drivers/mtd/nand/gpmi-nand/gpmi-nand.c | 25 +++++++++++++++++++++++++
> drivers/mtd/nand/gpmi-nand/gpmi-nand.h | 1 +
> 2 files changed, 26 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
> b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c index 8c0d2f0..e1e4c51 100644
> --- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
> +++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
> @@ -1512,12 +1512,34 @@ static int gpmi_pre_bbt_scan(struct gpmi_nand_data
> *this) return nand_boot_init(this);
> }
>
> +static int gpmi_verify_buf(struct mtd_info *mtd, const uint8_t *buf, int
> len) +{
> + struct nand_chip *chip = mtd->priv;
> + struct gpmi_nand_data *this = chip->priv;
> + int ret;
> +
> + ret = chip->ecc.read_page(mtd, chip, this->verify_buf, 0, 0);
> + if (ret)
> + return -EFAULT;
> + if (memcmp(buf, this->verify_buf, len))
> + return -EFAULT;
> + return 0;
> +}
> +
> static int gpmi_scan_bbt(struct mtd_info *mtd)
> {
> struct nand_chip *chip = mtd->priv;
> struct gpmi_nand_data *this = chip->priv;
> int ret;
>
> + /*
> + * We have gotten the right page size now, use it to allocate
> + * the proper verify buffer.
> + */
> + this->verify_buf = kzalloc(mtd->writesize, GFP_KERNEL);
devm_
> + if (!this->verify_buf)
> + return -ENOMEM;
> +
> /* Prepare for the BBT scan. */
> ret = gpmi_pre_bbt_scan(this);
> if (ret)
> @@ -1531,6 +1553,8 @@ void gpmi_nfc_exit(struct gpmi_nand_data *this)
> {
> nand_release(&this->mtd);
> gpmi_free_dma_buffer(this);
> + kfree(this->verify_buf);
> + this->verify_buf = NULL;
Then you won't have to care for this ... I told you at least once before.
> }
>
> static int __devinit gpmi_nfc_init(struct gpmi_nand_data *this)
> @@ -1556,6 +1580,7 @@ static int __devinit gpmi_nfc_init(struct
> gpmi_nand_data *this) chip->read_byte = gpmi_read_byte;
> chip->read_buf = gpmi_read_buf;
> chip->write_buf = gpmi_write_buf;
> + chip->verify_buf = gpmi_verify_buf;
> chip->ecc.read_page = gpmi_ecc_read_page;
> chip->ecc.write_page = gpmi_ecc_write_page;
> chip->ecc.read_oob = gpmi_ecc_read_oob;
> diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.h
> b/drivers/mtd/nand/gpmi-nand/gpmi-nand.h index 1547a60..8ddf115 100644
> --- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.h
> +++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.h
> @@ -144,6 +144,7 @@ struct gpmi_nand_data {
> /* MTD / NAND */
> struct nand_chip nand;
> struct mtd_info mtd;
> + uint8_t *verify_buf;
>
> /* General-use Variables */
> int current_chip;
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH v4] mtd: gpmi: add NAND write verify support
2012-08-11 14:10 ` Marek Vasut
@ 2012-08-11 15:15 ` Huang Shijie
2012-08-12 19:14 ` Marek Vasut
0 siblings, 1 reply; 6+ messages in thread
From: Huang Shijie @ 2012-08-11 15:15 UTC (permalink / raw)
To: linux-arm-kernel
On Sat, Aug 11, 2012 at 10:10 AM, Marek Vasut <marex@denx.de> wrote:
> Dear Huang Shijie,
>
>> Add NAND write verify support in gpmi-nand driver.
>>
>> This patch fixes a kernel crash when we select
>> CONFIG_MTD_NAND_VERIFY_WRITE=y, and do some write tests:
>>
>> root at freescale /$ dd if=/dev/zero of=/dev/mtd0 bs=128k count=1
>> [ 41.070000] Unable to handle kernel NULL pointer dereference at virtual
>> addr0 [ 41.080000] pgd = c77ac000
>> [ 41.080000] [00000000] *pgd=4773c831, *pte=00000000, *ppte=00000000
>> [ 41.090000] Internal error: Oops: 17 [#1] ARM
>> [ 41.090000] Modules linked in:
>> [ 41.090000] CPU: 0 Not tainted
>> (3.6.0-rc1-next-20120809-00002-ga25d017-d) [ 41.090000] PC is at
>> nand_verify_buf+0x18/0x5c
>> [ 41.090000] LR is at nand_write_page+0xc0/0x140
>> [ 41.090000] pc : [<c023e7d4>] lr : [<c023fcfc>] psr: 20000013
>> [ 41.090000] sp : c7779de4 ip : 00000000 fp : c6e60000
>> [ 41.090000] r10: 00000000 r9 : 00020000 r8 : 00000000
>> [ 41.090000] r7 : 00000000 r6 : c6e60000 r5 : c762cb10 r4 : 00000000
>> [ 41.090000] r3 : c762c8a8 r2 : 00000800 r1 : c6e60000 r0 : 00000000
>> [ 41.090000] Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment
>> user [ 41.090000] Control: 0005317f Table: 477ac000 DAC: 00000015
>> [ 41.090000] Process dd (pid: 427, stack limit = 0xc7778270)
>> [ 41.090000] Stack: (0xc7779de4 to 0xc777a000)
>> ...
>>
>> The crash log is fetched from Fabio's patch. thanks to Fabio's hard
> work.
>>
>> Cc: <stable@vger.kernel.org>
>> Reported-by: Fabio Estevam <fabio.estevam@freescale.com>
>> Signed-off-by: Huang Shijie <shijie8@gmail.com>
>> ---
>> v3 --> v4:
>> [1] add credit to Fabio.
>>
>> v2 --> v3:
>> [1] free the verify_buf when we exit.
>>
>> v1 --> v2:
>> [1] use the mtd->writesize to allocate the verify buffer.
>> [2] add new field `verify_buf` in gpmi_nand_data{}
>>
>> tested this patch on imx6q-arm2 board.
>> ---
>> drivers/mtd/nand/gpmi-nand/gpmi-nand.c | 25 +++++++++++++++++++++++++
>> drivers/mtd/nand/gpmi-nand/gpmi-nand.h | 1 +
>> 2 files changed, 26 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
>> b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c index 8c0d2f0..e1e4c51 100644
>> --- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
>> +++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
>> @@ -1512,12 +1512,34 @@ static int gpmi_pre_bbt_scan(struct gpmi_nand_data
>> *this) return nand_boot_init(this);
>> }
>>
>> +static int gpmi_verify_buf(struct mtd_info *mtd, const uint8_t *buf, int
>> len) +{
>> + struct nand_chip *chip = mtd->priv;
>> + struct gpmi_nand_data *this = chip->priv;
>> + int ret;
>> +
>> + ret = chip->ecc.read_page(mtd, chip, this->verify_buf, 0, 0);
>> + if (ret)
>> + return -EFAULT;
>> + if (memcmp(buf, this->verify_buf, len))
>> + return -EFAULT;
>> + return 0;
>> +}
>> +
>> static int gpmi_scan_bbt(struct mtd_info *mtd)
>> {
>> struct nand_chip *chip = mtd->priv;
>> struct gpmi_nand_data *this = chip->priv;
>> int ret;
>>
>> + /*
>> + * We have gotten the right page size now, use it to allocate
>> + * the proper verify buffer.
>> + */
>> + this->verify_buf = kzalloc(mtd->writesize, GFP_KERNEL);
>
> devm_
emm...
The devm_kzalloc() is the wrong choose in this case. It may makes we
waste much more memory when the NAND page is 8K.
Assume the gpmi uses a 8K page nand chip. The devm_kzalloc() will
allocate (sizeof(struct devres) + 8K).
It's obvious that the size is bigger then the SLUB_MAX_SIZE. So the
kernel gets 2 with the
get_order(sizeof(struct devres) + 8K) which means we have to use 4
memory page for the verify_buf.
But in actually, we only use 8K memory. So the rest nearly 8K(
sizeof(struct devres) is very small) memory
is wasted.
So I prefer to use the kzalloc() here.
thanks
Huang Shijie
>
>> + if (!this->verify_buf)
>> + return -ENOMEM;
>> +
>> /* Prepare for the BBT scan. */
>> ret = gpmi_pre_bbt_scan(this);
>> if (ret)
>> @@ -1531,6 +1553,8 @@ void gpmi_nfc_exit(struct gpmi_nand_data *this)
>> {
>> nand_release(&this->mtd);
>> gpmi_free_dma_buffer(this);
>> + kfree(this->verify_buf);
>> + this->verify_buf = NULL;
>
> Then you won't have to care for this ... I told you at least once before.
>
>> }
>>
>> static int __devinit gpmi_nfc_init(struct gpmi_nand_data *this)
>> @@ -1556,6 +1580,7 @@ static int __devinit gpmi_nfc_init(struct
>> gpmi_nand_data *this) chip->read_byte = gpmi_read_byte;
>> chip->read_buf = gpmi_read_buf;
>> chip->write_buf = gpmi_write_buf;
>> + chip->verify_buf = gpmi_verify_buf;
>> chip->ecc.read_page = gpmi_ecc_read_page;
>> chip->ecc.write_page = gpmi_ecc_write_page;
>> chip->ecc.read_oob = gpmi_ecc_read_oob;
>> diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.h
>> b/drivers/mtd/nand/gpmi-nand/gpmi-nand.h index 1547a60..8ddf115 100644
>> --- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.h
>> +++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.h
>> @@ -144,6 +144,7 @@ struct gpmi_nand_data {
>> /* MTD / NAND */
>> struct nand_chip nand;
>> struct mtd_info mtd;
>> + uint8_t *verify_buf;
>>
>> /* General-use Variables */
>> int current_chip;
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH v4] mtd: gpmi: add NAND write verify support
2012-08-11 15:15 ` Huang Shijie
@ 2012-08-12 19:14 ` Marek Vasut
2012-08-13 2:21 ` Huang Shijie
2012-08-13 2:35 ` Huang Shijie
0 siblings, 2 replies; 6+ messages in thread
From: Marek Vasut @ 2012-08-12 19:14 UTC (permalink / raw)
To: linux-arm-kernel
Dear Huang Shijie,
[...]
> >> + this->verify_buf = kzalloc(mtd->writesize, GFP_KERNEL);
> >
> > devm_
>
> emm...
> The devm_kzalloc() is the wrong choose in this case. It may makes we
> waste much more memory when the NAND page is 8K.
>
> Assume the gpmi uses a 8K page nand chip. The devm_kzalloc() will
> allocate (sizeof(struct devres) + 8K).
Don't forget the malloc header and padding around malloc()'d space. So you're
behind the 2 * PAGESIZE anyway.
> It's obvious that the size is bigger then the SLUB_MAX_SIZE. So the
> kernel gets 2 with the
> get_order(sizeof(struct devres) + 8K) which means we have to use 4
> memory page for the verify_buf.
> But in actually, we only use 8K memory. So the rest nearly 8K(
> sizeof(struct devres) is very small) memory
> is wasted.
>
> So I prefer to use the kzalloc() here.
>
> thanks
> Huang Shijie
>
> >> + if (!this->verify_buf)
> >> + return -ENOMEM;
> >> +
> >>
> >> /* Prepare for the BBT scan. */
> >> ret = gpmi_pre_bbt_scan(this);
> >> if (ret)
> >>
> >> @@ -1531,6 +1553,8 @@ void gpmi_nfc_exit(struct gpmi_nand_data *this)
> >>
> >> {
> >>
> >> nand_release(&this->mtd);
> >> gpmi_free_dma_buffer(this);
> >>
> >> + kfree(this->verify_buf);
> >> + this->verify_buf = NULL;
> >
> > Then you won't have to care for this ... I told you at least once before.
> >
> >> }
> >>
> >> static int __devinit gpmi_nfc_init(struct gpmi_nand_data *this)
> >>
> >> @@ -1556,6 +1580,7 @@ static int __devinit gpmi_nfc_init(struct
> >> gpmi_nand_data *this) chip->read_byte = gpmi_read_byte;
> >>
> >> chip->read_buf = gpmi_read_buf;
> >> chip->write_buf = gpmi_write_buf;
> >>
> >> + chip->verify_buf = gpmi_verify_buf;
> >>
> >> chip->ecc.read_page = gpmi_ecc_read_page;
> >> chip->ecc.write_page = gpmi_ecc_write_page;
> >> chip->ecc.read_oob = gpmi_ecc_read_oob;
> >>
> >> diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.h
> >> b/drivers/mtd/nand/gpmi-nand/gpmi-nand.h index 1547a60..8ddf115 100644
> >> --- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.h
> >> +++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.h
> >> @@ -144,6 +144,7 @@ struct gpmi_nand_data {
> >>
> >> /* MTD / NAND */
> >> struct nand_chip nand;
> >> struct mtd_info mtd;
> >>
> >> + uint8_t *verify_buf;
> >>
> >> /* General-use Variables */
> >> int current_chip;
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2012-08-13 2:35 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2012-08-12 2:07 [PATCH v4] mtd: gpmi: add NAND write verify support Huang Shijie
2012-08-11 14:10 ` Marek Vasut
2012-08-11 15:15 ` Huang Shijie
2012-08-12 19:14 ` Marek Vasut
2012-08-13 2:21 ` Huang Shijie
2012-08-13 2:35 ` Huang Shijie
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