Hi Jungseung,
Am 2020-01-23 07:22, schrieb Jungseung Lee:
Hi, Michael
2020-01-22 (Wed), 20:36 +0100, Michael Walle:
Hi,
> Currently, we are supporting block protection only for
> flash chips with 3 block protection bits in the SR register.
> This patch enables block protection support for some flash with
> 4 block protection bits(bp0-3).
>
> Signed-off-by: Jungseung Lee <js07.lee@xxxxxxxxxxx>
> ---
> v3 :
> Fix wrong ofs calculation on v2 patch
> v2 :
> Add sample table portion about 4bit block protection on the
> comment
> Trivial coding style change
>
> drivers/mtd/spi-nor/spi-nor.c | 127 +++++++++++++++++++++++++++++-
> ----
> include/linux/mtd/spi-nor.h | 8 +++
> 2 files changed, 119 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-
> nor/spi-nor.c
> index e3da6a8654a8..7e8af6c4fdfa 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -238,6 +238,14 @@ struct flash_info {
> * status register. Must be
> used with
> * SPI_NOR_HAS_TB.
> */
> +#define SPI_NOR_HAS_BP3 BIT(17) /*
> + * Flash SR has 4 bit fields
> (BP0-3)
> + * for block protection.
> + */
> +#define SPI_NOR_BP3_SR_BIT6 BIT(18) /*
> + * BP3 is bit 6 of status
> register.
> + * Must be used with
> SPI_NOR_HAS_BP3.
> + */
>
> /* Part specific fixup hooks. */
> const struct spi_nor_fixups *fixups;
> @@ -1767,23 +1775,47 @@ static void stm_get_locked_range(struct
> spi_nor *nor, u8 sr, loff_t *ofs,
> struct mtd_info *mtd = &nor->mtd;
> u8 mask = SR_BP2 | SR_BP1 | SR_BP0;
> u8 tb_mask = SR_TB_BIT5;
> - int pow;
> + u8 bp;
> + int pow = 0;
>
> if (nor->flags & SNOR_F_HAS_SR_TB_BIT6)
> tb_mask = SR_TB_BIT6;
>
> - if (!(sr & mask)) {
> - /* No protection */
> - *ofs = 0;
> - *len = 0;
> + if (nor->flags & SNOR_F_HAS_SR_BP3) {
> + u8 tmp;
> +
> + if (nor->flags & SNOR_F_HAS_SR_BP3_BIT6)
> + tmp = sr & (mask | SR_BP3_BIT6);
> + else
> + tmp = sr & (mask | SR_BP3_BIT5);
> +
> + if (tmp & SR_BP3_BIT6)
> + tmp = (tmp & ~BIT(6)) | BIT(5);
> +
> + bp = tmp >> SR_BP_SHIFT;
> + if (!bp) {
> + *ofs = 0;
> + *len = 0;
> + return;
> + }
> + if (bp <= ilog2(nor->n_sectors))
> + pow = ilog2(nor->n_sectors) + 1 - bp;
> } else {
> - pow = ((sr & mask) ^ mask) >> SR_BP_SHIFT;
> - *len = mtd->size >> pow;
> - if (nor->flags & SNOR_F_HAS_SR_TB && sr & tb_mask)
> + bp = (sr & mask) >> SR_BP_SHIFT;
> + if (!bp) {
> *ofs = 0;
> - else
> - *ofs = mtd->size - *len;
> + *len = 0;
> + return;
> + }
> + pow = bp ^ (mask >> SR_BP_SHIFT);
> }
> +
> + *len = mtd->size >> pow;
> +
> + if (nor->flags & SNOR_F_HAS_SR_TB && sr & tb_mask)
> + *ofs = 0;
> + else
> + *ofs = mtd->size - *len;
> }
>
> /*
> @@ -1823,7 +1855,7 @@ static int stm_is_unlocked_sr(struct spi_nor
> *nor, loff_t ofs, uint64_t len,
>
> /*
> * Lock a region of the flash. Compatible with ST Micro and
> similar flash.
> - * Supports the block protection bits BP{0,1,2} in the status
> register
> + * Supports the block protection bits BP{0,1,2,3} in the status
> register
> * (SR). Does not support these features found in newer SR
> bitfields:
> * - SEC: sector/block protect - only handle SEC=0 (block
> protect)
> * - CMP: complement protect - only support CMP=0 (range is not
> complemented)
> @@ -1831,7 +1863,7 @@ static int stm_is_unlocked_sr(struct spi_nor
> *nor, loff_t ofs, uint64_t len,
> * Support for the following is provided conditionally for some
> flash:
> * - TB: top/bottom protect
> *
> - * Sample table portion for 8MB flash (Winbond w25q64fw):
> + * Sample table portion for 8MB flash (Winbond w25q64fw / BP0-2):
> *
> * SEC | TB | BP2 | BP1 | BP0 | Prot Length |
> Protected Portion
> * ------------------------------------------------------------
> --------------
> @@ -1851,6 +1883,32 @@ static int stm_is_unlocked_sr(struct spi_nor
> *nor, loff_t ofs, uint64_t len,
> * 0 | 1 | 1 | 0 | 1 | 2 MB | Lower
> 1/4
> * 0 | 1 | 1 | 1 | 0 | 4 MB | Lower
> 1/2
> *
> + * Sample table portion for 64MB flash (Micron n25q512ax3 / BP0-
> 3):
> + *
> + * TB | BP3 | BP2 | BP1 | BP0 | Prot Length |
> Protected Portion
> + * ------------------------------------------------------------
> --------------
> + * 0 | 0 | 0 | 0 | 0 | NONE | NONE
> + * 0 | 0 | 0 | 0 | 1 | 64 KB | Upper
> 1/1024
> + * 0 | 0 | 0 | 1 | 0 | 128 KB | Upper
> 1/512
> + * 0 | 0 | 0 | 1 | 1 | 256 KB | Upper
> 1/256
> + * ...
> + * 0 | 1 | 0 | 0 | 1 | 16 MB | Upper
> 1/4
> + * 0 | 1 | 0 | 1 | 0 | 32 MB | Upper
> 1/2
> + * 0 | 1 | 0 | 1 | 1 | 64 MB | ALL
> + * 0 | 1 | 1 | 0 | 0 | 64 MB | ALL
> + * ...
> + * ------|-------|-------|-------|-------|---------------|-------
> ------------
> + * 1 | 0 | 0 | 0 | 0 | NONE | NONE
> + * 1 | 0 | 0 | 0 | 1 | 64 KB | Lower
> 1/1024
> + * 1 | 0 | 0 | 1 | 0 | 128 KB | Lower
> 1/512
> + * 1 | 0 | 0 | 1 | 1 | 256 KB | Lower
> 1/256
> + * ...
> + * 1 | 1 | 0 | 0 | 1 | 16 MB | Lower
> 1/4
> + * 1 | 1 | 0 | 1 | 0 | 32 MB | Lower
> 1/2
> + * 1 | 1 | 0 | 1 | 1 | 64 MB | ALL
> + * 1 | 1 | 1 | 0 | 0 | 64 MB | ALL
> + * ...
> + *
> * Returns negative on errors, 0 on success.
> */
> static int stm_lock(struct spi_nor *nor, loff_t ofs, uint64_t len)
> @@ -1898,6 +1956,12 @@ static int stm_lock(struct spi_nor *nor,
> loff_t ofs, uint64_t len)
> if (nor->flags & SNOR_F_HAS_SR_TB_BIT6)
> tb_mask = SR_TB_BIT6;
>
> + if (nor->flags & SNOR_F_HAS_SR_BP3) {
> + if (nor->flags & SNOR_F_HAS_SR_BP3_BIT6)
> + mask = mask | SR_BP3_BIT6;
> + else
> + mask = mask | SR_BP3_BIT5;
> + }
> /*
> * Need smallest pow such that:
> *
> @@ -1908,7 +1972,17 @@ static int stm_lock(struct spi_nor *nor,
> loff_t ofs, uint64_t len)
> * pow = ceil(log2(size / len)) = log2(size) -
> floor(log2(len))
> */
> pow = ilog2(mtd->size) - ilog2(lock_len);
> - val = mask - (pow << SR_BP_SHIFT);
> +
> + if (nor->flags & SNOR_F_HAS_SR_BP3) {
> + val = ilog2(nor->n_sectors) + 1 - pow;
Why do you use a new calculation here? As far as I can see, the
method is
the same except that is has one bit more. That also raises the
question why
n_sectors is now needed?
Can't we just initialize the mask with
mask = SR_BP2 | SR_BP1 | SR_BP0;
if (nor->flags & SNOR_F_HAS_SR_BP3)
mask |= SR_BP3_BIT5;
do the calculation and checks and then move the SR_BP3_BIT5 to
SR_BP3_BIT6
if SNOR_F_HAS_SR_BP3_BIT6 is set.
For most of flashes that supporting BP0-2, the smallest protected
portion is fixed as 1/64
and it can be properly handled by existing
calculation. (Actually it's not fully generic, see flashes like
w25q40bw or m25p80. Of course, it doesn't have SPI_NOR_HAS_LOCK flag
even though it has BP0-2 bit in SR)
No. The rules are always the same wether there are three or four BP
bits (the example in stm_lock() has not enough information on this):
(1) the first setting (besides 0) protects one sector. The second
protects 2, the third 4 and so on. eg 2^N
(2) the last setting is _always_ protect all, just like the '0' setting
is always protect none.
(3) if there is an overflow because there are no more free slots for
further settings (for 3 bits with flashes > 32MBit, for 4
bits if should be flashes > 16GBit), the first entry will be
discarded (eg the very first is the "just one sector" entry).
This is true for all flashes which uses this kind of setting, have a
look at the m25p80 or w25q40bw, these are no exception. It is just the
notation "lower 1/64" which is only true for flashes which either
overflows in (3) or fill all entries (eg. with 3bits that would be the
32Mbit version).
So for the 3 bit case the following flashes are border cases:
- 16mbit (less settings than slots)
- 32mbit (number of settings and free slots match)
- 64mbit (more settings than slots, first setting is discarded)
That being said, I suspect all the 16mbit flashes (and below) which have
the _LOCK bit set are broken, because the entries has to be shifted.
I'll
look into that later. This is the same "issue" you have with the 4 bits.
So if this is fixed, you should not need another formula for the 4 bit
case.
We need new calculation method for 4bit block protection and for making
it more generic, I choose n_sectors.
On all the flashes I checked, n_sectors is proper value for getting
block protected portion.
density portion n_sectors
W25M512JV 64MB 1/512 512
N25Q128A 16MB 1/256 256
N25Q512A 64MB 1/1024 1024
MT25QL02GCBB 256MB 1/4096 4096
The rules above apply to these flashes, too. Could you double check
that?
-michael
> + val = val << SR_BP_SHIFT;
> +
> + if (val & BIT(5) && mask & SR_BP3_BIT6)
> + val = (val & ~BIT(5)) | BIT(6);
> + } else {
> + val = mask - (pow << SR_BP_SHIFT);
> + }
> +
> if (val & ~mask)
> return -EINVAL;
> /* Don't "lock" with no region! */
> @@ -1983,6 +2057,13 @@ static int stm_unlock(struct spi_nor *nor,
> loff_t ofs, uint64_t len)
>
> if (nor->flags & SNOR_F_HAS_SR_TB_BIT6)
> tb_mask = SR_TB_BIT6;
> +
> + if (nor->flags & SNOR_F_HAS_SR_BP3) {
> + if (nor->flags & SNOR_F_HAS_SR_BP3_BIT6)
> + mask = mask | SR_BP3_BIT6;
> + else
> + mask = mask | SR_BP3_BIT5;
> + }
> /*
> * Need largest pow such that:
> *
> @@ -1995,13 +2076,20 @@ static int stm_unlock(struct spi_nor *nor,
> loff_t ofs, uint64_t len)
> pow = ilog2(mtd->size) - order_base_2(lock_len);
> if (lock_len == 0) {
> val = 0; /* fully unlocked */
> + } else if (nor->flags & SNOR_F_HAS_SR_BP3) {
> + val = ilog2(nor->n_sectors) + 1 - pow;
> + val = val << SR_BP_SHIFT;
> +
> + if (val & BIT(5) && mask & SR_BP3_BIT6)
> + val = (val & ~BIT(5)) | BIT(6);
> } else {
> val = mask - (pow << SR_BP_SHIFT);
> - /* Some power-of-two sizes are not supported */
> - if (val & ~mask)
> - return -EINVAL;
> }
>
> + /* Some power-of-two sizes are not supported */
> + if (val & ~mask)
> + return -EINVAL;
> +
> status_new = (status_old & ~mask & ~tb_mask) | val;
>
> /* Don't protect status register if we're fully unlocked */
> @@ -4736,6 +4824,7 @@ static void spi_nor_info_init_params(struct
> spi_nor *nor)
> /* Set SPI NOR sizes. */
> params->size = (u64)info->sector_size * info->n_sectors;
> params->page_size = info->page_size;
> + params->n_sectors = info->n_sectors;
>
> if (!(info->flags & SPI_NOR_NO_FR)) {
> /* Default to Fast Read for DT and non-DT platform
> devices. */
> @@ -5192,6 +5281,11 @@ int spi_nor_scan(struct spi_nor *nor, const
> char *name,
> nor->flags |= SNOR_F_NO_OP_CHIP_ERASE;
> if (info->flags & USE_CLSR)
> nor->flags |= SNOR_F_USE_CLSR;
> + if (info->flags & SPI_NOR_HAS_BP3) {
> + nor->flags |= SNOR_F_HAS_SR_BP3;
> + if (info->flags & SPI_NOR_BP3_SR_BIT6)
> + nor->flags |= SNOR_F_HAS_SR_BP3_BIT6;
> + }
>
> if (info->flags & SPI_NOR_NO_ERASE)
> mtd->flags |= MTD_NO_ERASE;
> @@ -5199,6 +5293,7 @@ int spi_nor_scan(struct spi_nor *nor, const
> char *name,
> mtd->dev.parent = dev;
> nor->page_size = params->page_size;
> mtd->writebufsize = nor->page_size;
> + nor->n_sectors = params->n_sectors;
>
> if (of_property_read_bool(np, "broken-flash-reset"))
> nor->flags |= SNOR_F_BROKEN_RESET;
> diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-
> nor.h
> index 541c06d042e8..92d550501daf 100644
> --- a/include/linux/mtd/spi-nor.h
> +++ b/include/linux/mtd/spi-nor.h
> @@ -129,7 +129,9 @@
> #define SR_BP1 BIT(3) /* Block protect 1
> */
> #define SR_BP2 BIT(4) /* Block protect 2
> */
> #define SR_TB_BIT5 BIT(5) /* Top/Bottom protect */
> +#define SR_BP3_BIT5 BIT(5) /* Block protect 3
> */
maybe just name it SR_BP3? would also be more consistent with the
proposal
above.
> #define SR_TB_BIT6 BIT(6) /* Top/Bottom protect */
> +#define SR_BP3_BIT6 BIT(6) /* Block protect 3
> */
> #define SR_SRWD BIT(7) /* SR write protect
> */
> /* Spansion/Cypress specific status bits */
> #define SR_E_ERR BIT(5)
> @@ -248,6 +250,8 @@ enum spi_nor_option_flags {
> SNOR_F_HAS_16BIT_SR = BIT(9),
> SNOR_F_NO_READ_CR = BIT(10),
> SNOR_F_HAS_SR_TB_BIT6 = BIT(11),
> + SNOR_F_HAS_SR_BP3 = BIT(12),
> + SNOR_F_HAS_SR_BP3_BIT6 = BIT(13),
>
> };
>
> @@ -519,6 +523,7 @@ struct spi_nor_locking_ops {
> *
> * @size: the flash memory density in bytes.
> * @page_size: the page size of the SPI NOR flash
> memory.
> + * @n_sectors: number of sectors
> * @hwcaps: describes the read and page program
> hardware
> * capabilities.
> * @reads: read capabilities ordered by priority: the
> higher index
> @@ -541,6 +546,7 @@ struct spi_nor_locking_ops {
> struct spi_nor_flash_parameter {
> u64 size;
> u32 page_size;
> + u16 n_sectors;
>
> struct spi_nor_hwcaps hwcaps;
> struct spi_nor_read_command reads[SNOR_CMD_READ_MAX];
> @@ -573,6 +579,7 @@ struct flash_info;
> * @bouncebuf_size: size of the bounce buffer
> * @info: spi-nor part JDEC MFR id and other info
> * @page_size: the page size of the SPI NOR
> + * @n_sector: number of sectors
> * @addr_width: number of address bytes
> * @erase_opcode: the opcode for erasing a sector
> * @read_opcode: the read opcode
> @@ -599,6 +606,7 @@ struct spi_nor {
> size_t bouncebuf_size;
> const struct flash_info *info;
> u32 page_size;
> + u16 n_sectors;
> u8 addr_width;
> u8 erase_opcode;
> u8 read_opcode;
> --
> 2.17.1
>
>
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