| Message ID | 20200318120615.4639-1-js07.lee@samsung.com |
|---|---|
| State | Superseded |
| Delegated to: | Ambarus Tudor |
| Headers | show |
| Series | [v2,1/3] mtd: spi-nor: reimplement block protection handling | expand |
Am 2020-03-18 13:06, schrieb Jungseung Lee: > The current mainline locking was restricted and could only be applied > to flashes that has 3 block protection bit and fixed locking ratio. > > A new method of normalization was reached at the end of the discussion > [1]. > > (1) - if bp slot is insufficient. > (2) - if bp slot is sufficient. > > if (bp_slots_needed > bp_slots) // (1) > min_prot_length = sector_size << (bp_slots_needed - bp_slots); > else // (2) > min_prot_length = sector_size; > > This patch changes logic to handle block protection based on > min_prot_length. > It is suitable for the overall flashes with exception of some corner > case > and easy to extend and apply for the case of 2bit or 4bit block > protection. > > [1] > http://lists.infradead.org/pipermail/linux-mtd/2020-February/093934.html > > Signed-off-by: Jungseung Lee <js07.lee@samsung.com> Reviewed-by: Michael Walle <michael@walle.cc> Tested with a W25Q32JW-IM. Tested-by: Michael Walle <michael@walle.cc> > --- > drivers/mtd/spi-nor/core.c | 110 ++++++++++++++++++++++--------------- > 1 file changed, 66 insertions(+), 44 deletions(-) > > diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c > index 877557dbda7f..e4ed8553aae8 100644 > --- a/drivers/mtd/spi-nor/core.c > +++ b/drivers/mtd/spi-nor/core.c > @@ -1514,29 +1514,64 @@ static int spi_nor_erase(struct mtd_info *mtd, > struct erase_info *instr) > return ret; > } > > +static u8 spi_nor_get_bp_mask(struct spi_nor *nor) > +{ > + return SR_BP2 | SR_BP1 | SR_BP0; > +} > + > +static u8 spi_nor_get_tb_mask(struct spi_nor *nor) > +{ > + if (nor->flags & SNOR_F_HAS_SR_TB_BIT6) > + return SR_TB_BIT6; > + else > + return SR_TB_BIT5; > +} > + > +static int spi_nor_get_min_prot_length(struct spi_nor *nor) > +{ > + int bp_slots, bp_slots_needed; > + u8 mask = spi_nor_get_bp_mask(nor); > + > + bp_slots = (mask >> SR_BP_SHIFT) + 1; > + > + /* Reserved one for "protect none" and one for "protect all". */ > + bp_slots = bp_slots - 2; > + > + bp_slots_needed = ilog2(nor->info->n_sectors); > + > + if (bp_slots_needed > bp_slots) > + return nor->info->sector_size << > + (bp_slots_needed - bp_slots); > + else > + return nor->info->sector_size; > +} > + > static void spi_nor_get_locked_range_sr(struct spi_nor *nor, u8 sr, > loff_t *ofs, > uint64_t *len) > { > struct mtd_info *mtd = &nor->mtd; > - u8 mask = SR_BP2 | SR_BP1 | SR_BP0; > - u8 tb_mask = SR_TB_BIT5; > - int pow; > - > - if (nor->flags & SNOR_F_HAS_SR_TB_BIT6) > - tb_mask = SR_TB_BIT6; > + int min_prot_len; > + u8 mask = spi_nor_get_bp_mask(nor); > + u8 tb_mask = spi_nor_get_tb_mask(nor); > + u8 bp = (sr & mask) >> SR_BP_SHIFT; > > - if (!(sr & mask)) { > + if (!bp) { > /* No protection */ > *ofs = 0; > *len = 0; > - } else { > - pow = ((sr & mask) ^ 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; > + return; > } > + > + min_prot_len = spi_nor_get_min_prot_length(nor); > + *len = min_prot_len << (bp - 1); > + > + if (*len > mtd->size) > + *len = mtd->size; > + > + if (nor->flags & SNOR_F_HAS_SR_TB && sr & tb_mask) > + *ofs = 0; > + else > + *ofs = mtd->size - *len; > } > > /* > @@ -1610,8 +1645,9 @@ static int spi_nor_sr_lock(struct spi_nor *nor, > loff_t ofs, uint64_t len) > { > struct mtd_info *mtd = &nor->mtd; > int ret, status_old, status_new; > - u8 mask = SR_BP2 | SR_BP1 | SR_BP0; > - u8 tb_mask = SR_TB_BIT5; > + int min_prot_len; > + u8 mask = spi_nor_get_bp_mask(nor); > + u8 tb_mask = spi_nor_get_tb_mask(nor); > u8 pow, val; > loff_t lock_len; > bool can_be_top = true, can_be_bottom = nor->flags & > SNOR_F_HAS_SR_TB; > @@ -1648,20 +1684,14 @@ static int spi_nor_sr_lock(struct spi_nor > *nor, loff_t ofs, uint64_t len) > else > lock_len = ofs + len; > > - if (nor->flags & SNOR_F_HAS_SR_TB_BIT6) > - tb_mask = SR_TB_BIT6; > + if (lock_len == mtd->size) { > + val = mask; /* fully locked */ > + } else { > + min_prot_len = spi_nor_get_min_prot_length(nor); > + pow = ilog2(lock_len) - ilog2(min_prot_len) + 1; > + val = pow << SR_BP_SHIFT; > + } > > - /* > - * Need smallest pow such that: > - * > - * 1 / (2^pow) <= (len / size) > - * > - * so (assuming power-of-2 size) we do: > - * > - * pow = ceil(log2(size / len)) = log2(size) - floor(log2(len)) > - */ > - pow = ilog2(mtd->size) - ilog2(lock_len); > - val = mask - (pow << SR_BP_SHIFT); > if (val & ~mask) > return -EINVAL; > /* Don't "lock" with no region! */ > @@ -1696,8 +1726,9 @@ static int spi_nor_sr_unlock(struct spi_nor > *nor, loff_t ofs, uint64_t len) > { > struct mtd_info *mtd = &nor->mtd; > int ret, status_old, status_new; > - u8 mask = SR_BP2 | SR_BP1 | SR_BP0; > - u8 tb_mask = SR_TB_BIT5; > + int min_prot_len; > + u8 mask = spi_nor_get_bp_mask(nor); > + u8 tb_mask = spi_nor_get_tb_mask(nor); > u8 pow, val; > loff_t lock_len; > bool can_be_top = true, can_be_bottom = nor->flags & > SNOR_F_HAS_SR_TB; > @@ -1734,22 +1765,13 @@ static int spi_nor_sr_unlock(struct spi_nor > *nor, loff_t ofs, uint64_t len) > else > lock_len = ofs; > > - if (nor->flags & SNOR_F_HAS_SR_TB_BIT6) > - tb_mask = SR_TB_BIT6; > - /* > - * Need largest pow such that: > - * > - * 1 / (2^pow) >= (len / size) > - * > - * so (assuming power-of-2 size) we do: > - * > - * pow = floor(log2(size / len)) = log2(size) - ceil(log2(len)) > - */ > - pow = ilog2(mtd->size) - order_base_2(lock_len); > if (lock_len == 0) { > val = 0; /* fully unlocked */ > } else { > - val = mask - (pow << SR_BP_SHIFT); > + min_prot_len = spi_nor_get_min_prot_length(nor); > + pow = ilog2(lock_len) - ilog2(min_prot_len) + 1; > + val = pow << SR_BP_SHIFT; > + > /* Some power-of-two sizes are not supported */ > if (val & ~mask) > return -EINVAL;
diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c index 877557dbda7f..e4ed8553aae8 100644 --- a/drivers/mtd/spi-nor/core.c +++ b/drivers/mtd/spi-nor/core.c @@ -1514,29 +1514,64 @@ static int spi_nor_erase(struct mtd_info *mtd, struct erase_info *instr) return ret; } +static u8 spi_nor_get_bp_mask(struct spi_nor *nor) +{ + return SR_BP2 | SR_BP1 | SR_BP0; +} + +static u8 spi_nor_get_tb_mask(struct spi_nor *nor) +{ + if (nor->flags & SNOR_F_HAS_SR_TB_BIT6) + return SR_TB_BIT6; + else + return SR_TB_BIT5; +} + +static int spi_nor_get_min_prot_length(struct spi_nor *nor) +{ + int bp_slots, bp_slots_needed; + u8 mask = spi_nor_get_bp_mask(nor); + + bp_slots = (mask >> SR_BP_SHIFT) + 1; + + /* Reserved one for "protect none" and one for "protect all". */ + bp_slots = bp_slots - 2; + + bp_slots_needed = ilog2(nor->info->n_sectors); + + if (bp_slots_needed > bp_slots) + return nor->info->sector_size << + (bp_slots_needed - bp_slots); + else + return nor->info->sector_size; +} + static void spi_nor_get_locked_range_sr(struct spi_nor *nor, u8 sr, loff_t *ofs, uint64_t *len) { struct mtd_info *mtd = &nor->mtd; - u8 mask = SR_BP2 | SR_BP1 | SR_BP0; - u8 tb_mask = SR_TB_BIT5; - int pow; - - if (nor->flags & SNOR_F_HAS_SR_TB_BIT6) - tb_mask = SR_TB_BIT6; + int min_prot_len; + u8 mask = spi_nor_get_bp_mask(nor); + u8 tb_mask = spi_nor_get_tb_mask(nor); + u8 bp = (sr & mask) >> SR_BP_SHIFT; - if (!(sr & mask)) { + if (!bp) { /* No protection */ *ofs = 0; *len = 0; - } else { - pow = ((sr & mask) ^ 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; + return; } + + min_prot_len = spi_nor_get_min_prot_length(nor); + *len = min_prot_len << (bp - 1); + + if (*len > mtd->size) + *len = mtd->size; + + if (nor->flags & SNOR_F_HAS_SR_TB && sr & tb_mask) + *ofs = 0; + else + *ofs = mtd->size - *len; } /* @@ -1610,8 +1645,9 @@ static int spi_nor_sr_lock(struct spi_nor *nor, loff_t ofs, uint64_t len) { struct mtd_info *mtd = &nor->mtd; int ret, status_old, status_new; - u8 mask = SR_BP2 | SR_BP1 | SR_BP0; - u8 tb_mask = SR_TB_BIT5; + int min_prot_len; + u8 mask = spi_nor_get_bp_mask(nor); + u8 tb_mask = spi_nor_get_tb_mask(nor); u8 pow, val; loff_t lock_len; bool can_be_top = true, can_be_bottom = nor->flags & SNOR_F_HAS_SR_TB; @@ -1648,20 +1684,14 @@ static int spi_nor_sr_lock(struct spi_nor *nor, loff_t ofs, uint64_t len) else lock_len = ofs + len; - if (nor->flags & SNOR_F_HAS_SR_TB_BIT6) - tb_mask = SR_TB_BIT6; + if (lock_len == mtd->size) { + val = mask; /* fully locked */ + } else { + min_prot_len = spi_nor_get_min_prot_length(nor); + pow = ilog2(lock_len) - ilog2(min_prot_len) + 1; + val = pow << SR_BP_SHIFT; + } - /* - * Need smallest pow such that: - * - * 1 / (2^pow) <= (len / size) - * - * so (assuming power-of-2 size) we do: - * - * pow = ceil(log2(size / len)) = log2(size) - floor(log2(len)) - */ - pow = ilog2(mtd->size) - ilog2(lock_len); - val = mask - (pow << SR_BP_SHIFT); if (val & ~mask) return -EINVAL; /* Don't "lock" with no region! */ @@ -1696,8 +1726,9 @@ static int spi_nor_sr_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len) { struct mtd_info *mtd = &nor->mtd; int ret, status_old, status_new; - u8 mask = SR_BP2 | SR_BP1 | SR_BP0; - u8 tb_mask = SR_TB_BIT5; + int min_prot_len; + u8 mask = spi_nor_get_bp_mask(nor); + u8 tb_mask = spi_nor_get_tb_mask(nor); u8 pow, val; loff_t lock_len; bool can_be_top = true, can_be_bottom = nor->flags & SNOR_F_HAS_SR_TB; @@ -1734,22 +1765,13 @@ static int spi_nor_sr_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len) else lock_len = ofs; - if (nor->flags & SNOR_F_HAS_SR_TB_BIT6) - tb_mask = SR_TB_BIT6; - /* - * Need largest pow such that: - * - * 1 / (2^pow) >= (len / size) - * - * so (assuming power-of-2 size) we do: - * - * pow = floor(log2(size / len)) = log2(size) - ceil(log2(len)) - */ - pow = ilog2(mtd->size) - order_base_2(lock_len); if (lock_len == 0) { val = 0; /* fully unlocked */ } else { - val = mask - (pow << SR_BP_SHIFT); + min_prot_len = spi_nor_get_min_prot_length(nor); + pow = ilog2(lock_len) - ilog2(min_prot_len) + 1; + val = pow << SR_BP_SHIFT; + /* Some power-of-two sizes are not supported */ if (val & ~mask) return -EINVAL;
The current mainline locking was restricted and could only be applied to flashes that has 3 block protection bit and fixed locking ratio. A new method of normalization was reached at the end of the discussion [1]. (1) - if bp slot is insufficient. (2) - if bp slot is sufficient. if (bp_slots_needed > bp_slots) // (1) min_prot_length = sector_size << (bp_slots_needed - bp_slots); else // (2) min_prot_length = sector_size; This patch changes logic to handle block protection based on min_prot_length. It is suitable for the overall flashes with exception of some corner case and easy to extend and apply for the case of 2bit or 4bit block protection. [1] http://lists.infradead.org/pipermail/linux-mtd/2020-February/093934.html Signed-off-by: Jungseung Lee <js07.lee@samsung.com> --- drivers/mtd/spi-nor/core.c | 110 ++++++++++++++++++++++--------------- 1 file changed, 66 insertions(+), 44 deletions(-)