On 29 September 2015 at 17:37, Fabio Estevam <fabio.este...@freescale.com> wrote: > Many SPI flashes have protection bits (BP2, BP1 and BP0) in the > status register that can protect selected regions of the SPI NOR. > > Take these bits into account when performing erase operations, > making sure that the protected areas are skipped. > > Introduce the CONFIG_SPI_FLASH_STM_PROTECT option that can be > selectedby systems that want to protect regions of SPI NOR flash > using the same programming model as in the ST Micro SPI NOR flashes, > like for example the M25P32. > > Based on the implementation from Brian Norris <computersforpe...@gmail.com> > for the Linux kernel: > https://patchwork.ozlabs.org/patch/513041/
This patch is still under review, will see how it moves. > > Tested on a mx6qsabresd: > > => sf probe > SF: Detected M25P32 with page size 256 Bytes, erase size 64 KiB, total 4 MiB > => sf protect on 0x3f0000 0x10000 > => sf erase 0x3f0000 0x10000 > offset 0x3f0000 is protected and cannot be erased > SF: 65536 bytes @ 0x3f0000 Erased: ERROR > => sf protect off 0x3f0000 0x10000 > => sf erase 0x3f0000 0x10000 > SF: 65536 bytes @ 0x3f0000 Erased: OK What if sf erase 0x3f0000 0x20000 - it should skip first 0x10000 from 0x3f0000 and then erase next 0x10000 from (0x3f0000+0x10000) did you verify this? > > Signed-off-by: Fabio Estevam <fabio.este...@freescale.com> > --- > Changes since v1: > - Add CONFIG_SPI_FLASH_STM_PROTECT in the Kconfig as suggested by > Stefan Roese > > common/cmd_sf.c | 30 +++++++ > drivers/mtd/spi/Kconfig | 15 ++++ > drivers/mtd/spi/sf_internal.h | 6 -- > drivers/mtd/spi/sf_ops.c | 188 > ++++++++++++++++++++++++++++++++++++++++++ > include/spi_flash.h | 25 +++++- > 5 files changed, 256 insertions(+), 8 deletions(-) > > diff --git a/common/cmd_sf.c b/common/cmd_sf.c > index ac7f5df..a31243f 100644 > --- a/common/cmd_sf.c > +++ b/common/cmd_sf.c > @@ -348,6 +348,28 @@ static int do_spi_flash_erase(int argc, char * const > argv[]) > return ret == 0 ? 0 : 1; > } > > +#ifdef CONFIG_SPI_FLASH_STM_PROTECT > +static int do_spi_protect(int argc, char * const argv[]) > +{ > + int start, len, ret = 0; > + > + if (argc != 4) > + return -1; > + > + start = simple_strtoull(argv[2], NULL, 16); > + len = simple_strtoull(argv[3], NULL, 16); > + > + if (strcmp(argv[1], "on") == 0) > + ret = stm_lock(flash, start, len); > + else if (strcmp(argv[1], "off") == 0) > + ret = stm_unlock(flash, start, len); > + else > + return -1; /* Unknown parameter */ > + > + return ret == 0 ? 0 : 1; > +} > +#endif > + > #ifdef CONFIG_CMD_SF_TEST > enum { > STAGE_ERASE, > @@ -540,6 +562,10 @@ static int do_spi_flash(cmd_tbl_t *cmdtp, int flag, int > argc, > ret = do_spi_flash_read_write(argc, argv); > else if (strcmp(cmd, "erase") == 0) > ret = do_spi_flash_erase(argc, argv); > +#ifdef CONFIG_SPI_FLASH_STM_PROTECT > + else if (strcmp(cmd, "protect") == 0) > + ret = do_spi_protect(argc, argv); > +#endif > #ifdef CONFIG_CMD_SF_TEST > else if (!strcmp(cmd, "test")) > ret = do_spi_flash_test(argc, argv); > @@ -579,5 +605,9 @@ U_BOOT_CMD( > "sf update addr offset|partition len - erase and write `len' bytes > from memory\n" > " at `addr' to flash at > `offset'\n" > " or to start of mtd > `partition'\n" > +#ifdef CONFIG_SPI_FLASH_STM_PROTECT > + "sf protect on/off sector len - protect/unprotect 'len' > bytes starting\n" > + " at address 'sector'\n" > +#endif > SF_TEST_HELP > ); > diff --git a/drivers/mtd/spi/Kconfig b/drivers/mtd/spi/Kconfig > index 3f7433c..2ee1089 100644 > --- a/drivers/mtd/spi/Kconfig > +++ b/drivers/mtd/spi/Kconfig > @@ -101,6 +101,21 @@ config SPI_FLASH_USE_4K_SECTORS > Please note that some tools/drivers/filesystems may not work with > 4096 B erase size (e.g. UBIFS requires 15 KiB as a minimum). > > +config SPI_FLASH_STM_PROTECT > + bool "Use STM flash protection mechanism" > + depends on SPI_FLASH > + help > + Enable the built-in protection mechanism provided by the > + BP2, BP1 and BP0 bits from the status register present > + on ST-Micro flashes such as M25P32. Please refer to the > + M25P32 datasheet to understand how to program these bits > + in order to protect a selected region of the SPI NOR flash. > + > + This same bit protection programming model applies to SPI > + NOR flashes from other manufacturers such as: > + - Micron M25P32 > + - SST SST25V32B > + > config SPI_FLASH_DATAFLASH > bool "AT45xxx DataFlash support" > depends on SPI_FLASH && DM_SPI_FLASH > diff --git a/drivers/mtd/spi/sf_internal.h b/drivers/mtd/spi/sf_internal.h > index 9c95d56..e66a62b 100644 > --- a/drivers/mtd/spi/sf_internal.h > +++ b/drivers/mtd/spi/sf_internal.h > @@ -162,12 +162,6 @@ int spi_flash_cmd_write(struct spi_slave *spi, const u8 > *cmd, size_t cmd_len, > /* Flash erase(sectors) operation, support all possible erase commands */ > int spi_flash_cmd_erase_ops(struct spi_flash *flash, u32 offset, size_t len); > > -/* Read the status register */ > -int spi_flash_cmd_read_status(struct spi_flash *flash, u8 *rs); > - > -/* Program the status register */ > -int spi_flash_cmd_write_status(struct spi_flash *flash, u8 ws); > - > /* Read the config register */ > int spi_flash_cmd_read_config(struct spi_flash *flash, u8 *rc); > > diff --git a/drivers/mtd/spi/sf_ops.c b/drivers/mtd/spi/sf_ops.c > index 900ec1f..e12f8ee 100644 > --- a/drivers/mtd/spi/sf_ops.c > +++ b/drivers/mtd/spi/sf_ops.c > @@ -573,3 +573,191 @@ int sst_write_bp(struct spi_flash *flash, u32 offset, > size_t len, > return ret; > } > #endif > + > +#ifdef CONFIG_SPI_FLASH_STM_PROTECT > +#define SR_BP0 BIT(2) /* Block protect 0 */ > +#define SR_BP1 BIT(3) /* Block protect 1 */ > +#define SR_BP2 BIT(4) /* Block protect 2 */ > + > +static void stm_get_locked_range(struct spi_flash *nor, u8 sr, loff_t *ofs, > + u32 *len) > +{ > + u8 mask = SR_BP2 | SR_BP1 | SR_BP0; > + int shift = ffs(mask) - 1; > + int pow; > + > + if (!(sr & mask)) { > + /* No protection */ > + *ofs = 0; > + *len = 0; > + } else { > + pow = ((sr & mask) ^ mask) >> shift; > + *len = nor->size >> pow; > + *ofs = nor->size - *len; > + } > +} > + > +/* > + * Return 1 if the entire region is locked, 0 otherwise > + */ > +static int stm_is_locked_sr(struct spi_flash *nor, loff_t ofs, u32 len, > + u8 sr) > +{ > + loff_t lock_offs; > + u32 lock_len; > + > + stm_get_locked_range(nor, sr, &lock_offs, &lock_len); > + > + return (ofs + len <= lock_offs + lock_len) && (ofs >= lock_offs); > +} > + > +/* > + * Check if a region of the flash is (completely) locked. See stm_lock() for > + * more info. > + * > + * Returns 1 if entire region is locked, 0 if any portion is unlocked, and > + * negative on errors. > + */ > +int stm_is_locked(struct spi_flash *nor, loff_t ofs, u32 len) > +{ > + int status; > + u8 sr; > + > + status = spi_flash_cmd_read_status(nor, &sr); > + if (status < 0) > + return status; > + > + return stm_is_locked_sr(nor, ofs, len, sr); > +} > + > +/* > + * Lock a region of the flash. Compatible with ST Micro and similar flash. > + * Supports only the block protection bits BP{0,1,2} in the status register > + * (SR). Does not support these features found in newer SR bitfields: > + * - TB: top/bottom protect - only handle TB=0 (top protect) > + * - SEC: sector/block protect - only handle SEC=0 (block protect) > + * - CMP: complement protect - only support CMP=0 (range is not > complemented) > + * > + * Sample table portion for 8MB flash (Winbond w25q64fw): > + * > + * SEC | TB | BP2 | BP1 | BP0 | Prot Length | Protected Portion > + * > -------------------------------------------------------------------------- > + * X | X | 0 | 0 | 0 | NONE | NONE > + * 0 | 0 | 0 | 0 | 1 | 128 KB | Upper 1/64 > + * 0 | 0 | 0 | 1 | 0 | 256 KB | Upper 1/32 > + * 0 | 0 | 0 | 1 | 1 | 512 KB | Upper 1/16 > + * 0 | 0 | 1 | 0 | 0 | 1 MB | Upper 1/8 > + * 0 | 0 | 1 | 0 | 1 | 2 MB | Upper 1/4 > + * 0 | 0 | 1 | 1 | 0 | 4 MB | Upper 1/2 > + * X | X | 1 | 1 | 1 | 8 MB | ALL > + * > + * Returns negative on errors, 0 on success. > + */ > +int stm_lock(struct spi_flash *nor, u32 ofs, u32 len) > +{ > + u8 status_old, status_new; > + u8 mask = SR_BP2 | SR_BP1 | SR_BP0; > + u8 shift = ffs(mask) - 1, pow, val; > + > + spi_flash_cmd_read_status(nor, &status_old); > + > + /* SPI NOR always locks to the end */ > + if (ofs + len != nor->size) { > + /* Does combined region extend to end? */ > + if (!stm_is_locked_sr(nor, ofs + len, nor->size - ofs - len, > + status_old)) > + return -EINVAL; > + len = nor->size - ofs; > + } > + > + /* > + * 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(nor->size) - __ilog2(len); > + val = mask - (pow << shift); > + if (val & ~mask) > + return -EINVAL; > + > + /* Don't "lock" with no region! */ > + if (!(val & mask)) > + return -EINVAL; > + > + status_new = (status_old & ~mask) | val; > + > + /* Only modify protection if it will not unlock other areas */ > + if ((status_new & mask) <= (status_old & mask)) > + return -EINVAL; > + > + spi_flash_cmd_write_status(nor, status_new); > + > + return 0; > +} > + > +/* > + * Unlock a region of the flash. See stm_lock() for more info > + * > + * Returns negative on errors, 0 on success. > + */ > +int stm_unlock(struct spi_flash *nor, u32 ofs, u32 len) > +{ > + uint8_t status_old, status_new; > + u8 mask = SR_BP2 | SR_BP1 | SR_BP0; > + u8 shift = ffs(mask) - 1, pow, val; > + > + spi_flash_cmd_read_status(nor, &status_old); > + > + /* Cannot unlock; would unlock larger region than requested */ > + if (stm_is_locked_sr(nor, status_old, ofs - nor->erase_size, > + nor->erase_size)) > + return -EINVAL; > + /* > + * 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(nor->size) - order_base_2(nor->size - (ofs + len)); > + if (ofs + len == nor->size) { > + val = 0; /* fully unlocked */ > + } else { > + val = mask - (pow << shift); > + /* Some power-of-two sizes are not supported */ > + if (val & ~mask) > + return -EINVAL; > + } > + > + status_new = (status_old & ~mask) | val; > + > + /* Only modify protection if it will not lock other areas */ > + if ((status_new & mask) >= (status_old & mask)) > + return -EINVAL; > + > + spi_flash_cmd_write_status(nor, status_new); > + > + return 0; > +} > +#else > +int stm_is_locked(struct spi_flash *nor, loff_t ofs, u32 len) > +{ > + return 0; > +} > + > +int stm_lock(struct spi_flash *nor, u32 ofs, u32 len) > +{ > + return 0; > +} > + > +int stm_unlock(struct spi_flash *nor, u32 ofs, u32 len) > +{ > + return 0; > +} > +#endif /* CONFIG_SPI_FLASH_STM_PROTECT */ > diff --git a/include/spi_flash.h b/include/spi_flash.h > index 3b2d555..434323e 100644 > --- a/include/spi_flash.h > +++ b/include/spi_flash.h > @@ -115,6 +115,17 @@ struct dm_spi_flash_ops { > int (*erase)(struct udevice *dev, u32 offset, size_t len); > }; > > + > +/* Read the status register */ > +int spi_flash_cmd_read_status(struct spi_flash *flash, u8 *rs); > + > +/* Program the status register */ > +int spi_flash_cmd_write_status(struct spi_flash *flash, u8 ws); > + > +int stm_is_locked(struct spi_flash *nor, loff_t ofs, u32 len); > +int stm_lock(struct spi_flash *nor, u32 ofs, u32 len); > +int stm_unlock(struct spi_flash *nor, u32 ofs, u32 len); > + > /* Access the serial operations for a device */ > #define sf_get_ops(dev) ((struct dm_spi_flash_ops *)(dev)->driver->ops) > > @@ -219,13 +230,23 @@ static inline int spi_flash_read(struct spi_flash > *flash, u32 offset, > static inline int spi_flash_write(struct spi_flash *flash, u32 offset, > size_t len, const void *buf) > { > - return flash->write(flash, offset, len, buf); > + if (stm_is_locked(flash, offset, len) > 0) { > + printf("offset 0x%x is protected and cannot be written\n", > offset); > + return -EINVAL; > + } else { > + return flash->write(flash, offset, len, buf); > + } > } > > static inline int spi_flash_erase(struct spi_flash *flash, u32 offset, > size_t len) > { > - return flash->erase(flash, offset, len); > + if (stm_is_locked(flash, offset, len) > 0) { > + printf("offset 0x%x is protected and cannot be erased\n", > offset); > + return -EINVAL; > + } else { > + return flash->erase(flash, offset, len); > + } > } > #endif > > -- > 1.9.1 > -- Jagan. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot