| Message ID | 1344737275-18342-1-git-send-email-shijie8@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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@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;
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@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;
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;
? 2012?08?13? 03:14, Marek Vasut ??: > Don't forget the malloc header and padding around malloc()'d space. So you're > behind the 2 * PAGESIZE anyway. If we use the kzalloc(). There is no malloc header and padding. We get the memory by the __get_free_pages(). So we do _NOT_ behind the 2*PAGE. We use exactly the 2*PAGE. thanks Huang Shijie
? 2012?08?13? 03:14, Marek Vasut ??: > Don't forget the malloc header and padding around malloc()'d space. So you're > behind the 2 * PAGESIZE anyway. > sorry, I misunderstood your meaning. My meaning is even the SLUB maybe costs some extra memory, it still save much memory then we use the devm_kzalloc(). thanks Huang Shijie
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;
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@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(-)