Hi, Eugeniy, Sorry that I reply to this email and not to the patch itself, I haven't received it. It's because of my funny email server :). On 10/15/2018 05:21 PM, Eugeniy Paltsev wrote: > Hi! > > Maybe you have any comments or remarks about this patch? > And if you don't could you please apply it. Thanks! > > On Mon, 2018-09-10 at 14:46 +0300, Eugeniy Paltsev wrote: >> sst26wf flash series block protection implementation differs >> from other SST series, so add specific implementation >> flash_lock/flash_unlock/flash_is_locked functions for sst26wf >> flash ICs. >> >> NOTE: >> this patch is basically following mine u-boot commit port: >> http://git.denx.de/?p=u-boot.git;a=commitdiff;h=3d4fed87a5fa3ffedf64ff2811cd95c5ac4503ac >> >> Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@xxxxxxxxxxxx> >> --- >> Changes v1->v2: >> * Check return value of {read | write}_reg callbacks. >> >> drivers/mtd/spi-nor/spi-nor.c | 177 ++++++++++++++++++++++++++++++++++++++++++ >> include/linux/mtd/spi-nor.h | 4 + >> 2 files changed, 181 insertions(+) >> >> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c >> index d9c368c44194..d0e7c85b6002 100644 >> --- a/drivers/mtd/spi-nor/spi-nor.c >> +++ b/drivers/mtd/spi-nor/spi-nor.c >> @@ -598,6 +598,177 @@ static int write_sr_and_check(struct spi_nor *nor, u8 status_new, u8 mask) >> return ((ret & mask) != (status_new & mask)) ? -EIO : 0; >> } >> >> +/* >> + * sst26wf016/sst26wf032/sst26wf064 have next block protection: >> + * 4x - 8 KByte blocks - read & write protection bits - upper addresses >> + * 1x - 32 KByte blocks - write protection bits >> + * rest - 64 KByte blocks - write protection bits >> + * 1x - 32 KByte blocks - write protection bits >> + * 4x - 8 KByte blocks - read & write protection bits - lower addresses >> + * >> + * We'll support only per 64k lock/unlock so lower and upper 64 KByte region >> + * will be treated as single block. You are treating the memory as uniform, thus addressing just part of the individual-block lock support. The advantages of having non-uniform block locks disappear. I would prefer to be able to lock each individual block. >> + */ >> +#define SST26_BPR_8K_NUM 4 >> +#define SST26_MAX_BPR_REG_LEN (18 + 1) 18 + 1 doesn't say much. It's rather a personal preference, but I would define it like: /* BPR maximum length in bytes (SST26 maximum flash size is 64 Mbits). */ #define SST26_BPR_MAX_LEN (SZ_8M / SZ_64K / BITS_PER_BYTE) Note that the result is actually 18, you have: (126 (64kB blocks) + 2 (32kB blocks) + 2 bits * 8 (8kB blocks)) / 8 = 18 >> +#define SST26_BOUND_REG_SIZE ((32 + SST26_BPR_8K_NUM * 8) * SZ_1K) this is always 64K. I would drop the math, directly assign 64k and rename it with something like SST26_HYBRID_SIZE. SST26_BPR_8K_NUM will disappear. >> + >> +enum lock_ctl { >> + SST26_CTL_LOCK, >> + SST26_CTL_UNLOCK, >> + SST26_CTL_CHECK >> +}; >> + >> +static bool sst26_process_bpr(u32 bpr_size, u8 *cmd, u32 bit, enum lock_ctl ctl) >> +{ >> + switch (ctl) { >> + case SST26_CTL_LOCK: >> + cmd[bpr_size - (bit / 8) - 1] |= BIT(bit % 8);>> + break; >> + case SST26_CTL_UNLOCK: >> + cmd[bpr_size - (bit / 8) - 1] &= ~BIT(bit % 8); >> + break; >> + case SST26_CTL_CHECK: >> + return !!(cmd[bpr_size - (bit / 8) - 1] & BIT(bit % 8)); >> + } >> + >> + return false; >> +} >> + >> +/* >> + * Lock, unlock or check lock status of the flash region of the flash (depending >> + * on the lock_ctl value) kernel doc comments would be nice >> + */ >> +static int sst26_lock_ctl(struct spi_nor *nor, loff_t ofs, uint64_t len, enum lock_ctl ctl) WARNING: line over 80 characters #91: FILE: drivers/mtd/spi-nor/spi-nor.c:642: +static int sst26_lock_ctl(struct spi_nor *nor, loff_t ofs, uint64_t len, enum lock_ctl ctl) >> +{ >> + struct mtd_info *mtd = &nor->mtd; >> + u32 i, bpr_ptr, rptr_64k, lptr_64k, bpr_size; >> + bool lower_64k = false, upper_64k = false; >> + u8 bpr_buff[SST26_MAX_BPR_REG_LEN] = {}; >> + int ret; I would reorder the declarations to avoid stack padding: pointers, u32, int, u8 and bool. >> + >> + /* Check length and offset for 64k alignment */ >> + if ((ofs & (SZ_64K - 1)) || (len & (SZ_64K - 1))) { >> + dev_err(nor->dev, "length or offset is not 64KiB allighned\n"); s/allighned/aligned >> + return -EINVAL; >> + } >> + >> + if (ofs + len > mtd->size) { >> + dev_err(nor->dev, "range is more than device size: %#llx + %#llx > %#llx\n", >> + ofs, len, mtd->size); >> + return -EINVAL; >> + } >> + >> + /* SST26 family has only 16 Mbit, 32 Mbit and 64 Mbit IC */ >> + if (mtd->size != SZ_2M && >> + mtd->size != SZ_4M && >> + mtd->size != SZ_8M) It's strange to see a mtd->size check here. This silently implies that there might be cases that are not treated by this code. >> + return -EINVAL; >> + >> + bpr_size = 2 + (mtd->size / SZ_64K / 8); 2 is not needed if I understood correctly. >> + >> + ret = nor->read_reg(nor, SPINOR_OP_READ_BPR, bpr_buff, bpr_size); ok, I guess you did the mtd->size check to avoid bpr_buff overflow. Wouldn't be better to get rid of the mtd->size check and to allocate the buffer on heap using bpr_size? >> + if (ret < 0) { >> + dev_err(nor->dev, "fail to read block-protection register\n"); >> + return ret; >> + } >> + >> + rptr_64k = min_t(u32, ofs + len, mtd->size - SST26_BOUND_REG_SIZE); >> + lptr_64k = max_t(u32, ofs, SST26_BOUND_REG_SIZE); >> + >> + upper_64k = ((ofs + len) > (mtd->size - SST26_BOUND_REG_SIZE)); >> + lower_64k = (ofs < SST26_BOUND_REG_SIZE); >> + >> + /* Lower bits in block-protection register are about 64k region */ >> + bpr_ptr = lptr_64k / SZ_64K - 1; >> + >> + /* Process 64K blocks region */ >> + while (lptr_64k < rptr_64k) { >> + if (sst26_process_bpr(bpr_size, bpr_buff, bpr_ptr, ctl)) >> + return EACCES; >> + >> + bpr_ptr++; >> + lptr_64k += SZ_64K; >> + } >> + >> + /* 32K and 8K region bits in BPR are after 64k region bits */ >> + bpr_ptr = (mtd->size - 2 * SST26_BOUND_REG_SIZE) / SZ_64K; >> + >> + /* Process lower 32K block region */ >> + if (lower_64k) >> + if (sst26_process_bpr(bpr_size, bpr_buff, bpr_ptr, ctl)) >> + return EACCES; >> + >> + bpr_ptr++; >> + >> + /* Process upper 32K block region */ >> + if (upper_64k) >> + if (sst26_process_bpr(bpr_size, bpr_buff, bpr_ptr, ctl)) >> + return EACCES; >> + >> + bpr_ptr++; >> + >> + /* Process lower 8K block regions */ >> + for (i = 0; i < SST26_BPR_8K_NUM; i++) { >> + if (lower_64k) >> + if (sst26_process_bpr(bpr_size, bpr_buff, bpr_ptr, ctl)) >> + return EACCES; >> + >> + /* In 8K area BPR has both read and write protection bits */ >> + bpr_ptr += 2; >> + } >> + >> + /* Process upper 8K block regions */ >> + for (i = 0; i < SST26_BPR_8K_NUM; i++) { >> + if (upper_64k) >> + if (sst26_process_bpr(bpr_size, bpr_buff, bpr_ptr, ctl)) >> + return EACCES; >> + >> + /* In 8K area BPR has both read and write protection bits */ however you treat just the write protection bit. Am I missing something? >> + bpr_ptr += 2; >> + } >> + >> + /* If we check region status we don't need to write BPR back */ >> + if (ctl == SST26_CTL_CHECK) >> + return 0; >> + >> + ret = nor->write_reg(nor, SPINOR_OP_WRITE_BPR, bpr_buff, bpr_size); >> + if (ret < 0) { >> + dev_err(nor->dev, "fail to write block-protection register\n"); >> + return ret; >> + } >> + >> + return 0; >> +} >> + >> +static int sst26_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len) >> +{ >> + return sst26_lock_ctl(nor, ofs, len, SST26_CTL_UNLOCK); >> +} >> + >> +static int sst26_lock(struct spi_nor *nor, loff_t ofs, uint64_t len) >> +{ >> + return sst26_lock_ctl(nor, ofs, len, SST26_CTL_LOCK); >> +} >> + >> +/* >> + * Returns EACCES (positive value) if region is locked, 0 if region is unlocked, It would be better to be consistent with mtd-utils and return 1 if the region is locked. >> + * and negative on errors. >> + */ >> +static int sst26_is_locked(struct spi_nor *nor, loff_t ofs, uint64_t len) >> +{ >> + /* >> + * is_locked function is used for check before reading or erasing flash >> + * region, so offset and length might be not 64k allighned, so adjust >> + * them to be 64k allighned as sst26_lock_ctl works only with 64k >> + * allighned regions. s/allighned/aligned >> + */ >> + ofs -= ofs & (SZ_64K - 1); >> + len = len & (SZ_64K - 1) ? (len & ~(SZ_64K - 1)) + SZ_64K : len; >> + >> + return sst26_lock_ctl(nor, ofs, len, SST26_CTL_CHECK); >> +} >> + >> static void stm_get_locked_range(struct spi_nor *nor, u8 sr, loff_t *ofs, >> uint64_t *len) >> { >> @@ -2872,6 +3043,12 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, >> nor->flash_is_locked = stm_is_locked; >> } >> >> + if (JEDEC_MFR(info) == SNOR_MFR_SST && info->id[1] == 0x26) { This implies the entire sst26 family. Did you check that the individual-block protection is the same on all flashes? Cheers, ta >> + nor->flash_lock = sst26_lock; >> + nor->flash_unlock = sst26_unlock; >> + nor->flash_is_locked = sst26_is_locked; >> + } >> + >> if (nor->flash_lock && nor->flash_unlock && nor->flash_is_locked) { >> mtd->_lock = spi_nor_lock; >> mtd->_unlock = spi_nor_unlock; >> diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h >> index e60da0d34cc1..246014a73f83 100644 >> --- a/include/linux/mtd/spi-nor.h >> +++ b/include/linux/mtd/spi-nor.h >> @@ -93,6 +93,10 @@ >> #define SPINOR_OP_WRDI 0x04 /* Write disable */ >> #define SPINOR_OP_AAI_WP 0xad /* Auto address increment word program */ >> >> +/* Used for SST26* flashes only. */ >> +#define SPINOR_OP_READ_BPR 0x72 /* Read block protection register */ >> +#define SPINOR_OP_WRITE_BPR 0x42 /* Write block protection register */ >> + >> /* Used for S3AN flashes only */ >> #define SPINOR_OP_XSE 0x50 /* Sector erase */ >> #define SPINOR_OP_XPP 0x82 /* Page program */ _______________________________________________ linux-snps-arc mailing list linux-snps-arc@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/linux-snps-arc
