diff options
| -rw-r--r-- | drivers/mtd/spi-nor/spi-nor.c | 68 |
1 files changed, 50 insertions, 18 deletions
diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c index 3dde727..680bc15 100644 --- a/drivers/mtd/spi-nor/spi-nor.c +++ b/drivers/mtd/spi-nor/spi-nor.c @@ -439,17 +439,38 @@ static void stm_get_locked_range(struct spi_nor *nor, u8 sr, loff_t *ofs, } /* - * Return 1 if the entire region is locked, 0 otherwise + * Return 1 if the entire region is locked (if @locked is true) or unlocked (if + * @locked is false); 0 otherwise */ -static int stm_is_locked_sr(struct spi_nor *nor, loff_t ofs, uint64_t len, - u8 sr) +static int stm_check_lock_status_sr(struct spi_nor *nor, loff_t ofs, uint64_t len, + u8 sr, bool locked) { loff_t lock_offs; uint64_t lock_len; + if (!len) + return 1; + stm_get_locked_range(nor, sr, &lock_offs, &lock_len); - return (ofs + len <= lock_offs + lock_len) && (ofs >= lock_offs); + if (locked) + /* Requested range is a sub-range of locked range */ + return (ofs + len <= lock_offs + lock_len) && (ofs >= lock_offs); + else + /* Requested range does not overlap with locked range */ + return (ofs >= lock_offs + lock_len) || (ofs + len <= lock_offs); +} + +static int stm_is_locked_sr(struct spi_nor *nor, loff_t ofs, uint64_t len, + u8 sr) +{ + return stm_check_lock_status_sr(nor, ofs, len, sr, true); +} + +static int stm_is_unlocked_sr(struct spi_nor *nor, loff_t ofs, uint64_t len, + u8 sr) +{ + return stm_check_lock_status_sr(nor, ofs, len, sr, false); } /* @@ -481,20 +502,24 @@ static int stm_lock(struct spi_nor *nor, loff_t ofs, uint64_t len) int status_old, status_new; u8 mask = SR_BP2 | SR_BP1 | SR_BP0; u8 shift = ffs(mask) - 1, pow, val; + loff_t lock_len; int ret; status_old = read_sr(nor); if (status_old < 0) return status_old; - /* SPI NOR always locks to the end */ - if (ofs + len != mtd->size) { - /* Does combined region extend to end? */ - if (!stm_is_locked_sr(nor, ofs + len, mtd->size - ofs - len, - status_old)) - return -EINVAL; - len = mtd->size - ofs; - } + /* If nothing in our range is unlocked, we don't need to do anything */ + if (stm_is_locked_sr(nor, ofs, len, status_old)) + return 0; + + /* If anything above us is unlocked, we can't use 'top' protection */ + if (!stm_is_locked_sr(nor, ofs + len, mtd->size - (ofs + len), + status_old)) + return -EINVAL; + + /* lock_len: length of region that should end up locked */ + lock_len = mtd->size - ofs; /* * Need smallest pow such that: @@ -505,7 +530,7 @@ 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(len); + pow = ilog2(mtd->size) - ilog2(lock_len); val = mask - (pow << shift); if (val & ~mask) return -EINVAL; @@ -541,17 +566,24 @@ static int stm_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len) int status_old, status_new; u8 mask = SR_BP2 | SR_BP1 | SR_BP0; u8 shift = ffs(mask) - 1, pow, val; + loff_t lock_len; int ret; status_old = read_sr(nor); if (status_old < 0) return status_old; - /* Cannot unlock; would unlock larger region than requested */ - if (stm_is_locked_sr(nor, ofs - mtd->erasesize, mtd->erasesize, - status_old)) + /* If nothing in our range is locked, we don't need to do anything */ + if (stm_is_unlocked_sr(nor, ofs, len, status_old)) + return 0; + + /* If anything below us is locked, we can't use 'top' protection */ + if (!stm_is_unlocked_sr(nor, 0, ofs, status_old)) return -EINVAL; + /* lock_len: length of region that should remain locked */ + lock_len = mtd->size - (ofs + len); + /* * Need largest pow such that: * @@ -561,8 +593,8 @@ static int stm_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len) * * pow = floor(log2(size / len)) = log2(size) - ceil(log2(len)) */ - pow = ilog2(mtd->size) - order_base_2(mtd->size - (ofs + len)); - if (ofs + len == mtd->size) { + pow = ilog2(mtd->size) - order_base_2(lock_len); + if (lock_len == 0) { val = 0; /* fully unlocked */ } else { val = mask - (pow << shift); |
