From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wg0-f41.google.com ([74.125.82.41]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WSMbv-0002Bs-I5 for linux-mtd@lists.infradead.org; Tue, 25 Mar 2014 08:21:36 +0000 Received: by mail-wg0-f41.google.com with SMTP id n12so78370wgh.0 for ; Tue, 25 Mar 2014 01:21:05 -0700 (PDT) From: Lee Jones To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [RFC 25/47] mtd: nand: stm_nand_bch: bad block marking helpers Date: Tue, 25 Mar 2014 08:19:42 +0000 Message-Id: <1395735604-26706-26-git-send-email-lee.jones@linaro.org> In-Reply-To: <1395735604-26706-1-git-send-email-lee.jones@linaro.org> References: <1395735604-26706-1-git-send-email-lee.jones@linaro.org> Cc: angus.clark@st.com, kernel@stlinux.com, lee.jones@linaro.org, linux-mtd@lists.infradead.org, pekon@ti.com, computersforpeace@gmail.com, dwmw2@infradead.org List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Bad Block Markers (BBMs) keep track of unusable/unsuitable memory blocks which can prevent unnecessary data loss. These helpers aid in reading and writing to/from the Bad Block Tables (BBTs) where the BBMs are stored. Signed-off-by: Lee Jones --- drivers/mtd/nand/stm_nand_bch.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/drivers/mtd/nand/stm_nand_bch.c b/drivers/mtd/nand/stm_nand_bch.c index 5bcaabbc..e1c71be 100644 --- a/drivers/mtd/nand/stm_nand_bch.c +++ b/drivers/mtd/nand/stm_nand_bch.c @@ -495,6 +495,35 @@ static uint8_t bch_write_page(struct nandi_controller *nandi, return status; } +/* + * Bad Block Tables/Bad Block Markers + */ +#define BBT_MARK_BAD_FACTORY 0x0 +#define BBT_MARK_BAD_WEAR 0x1 +#define BBT_MARK_GOOD 0x3 + +static void bbt_set_block_mark(uint8_t *bbt, uint32_t block, uint8_t mark) +{ + unsigned int byte = block >> 2; + unsigned int shift = (block & 0x3) << 1; + + bbt[byte] &= ~(0x3 << shift); + bbt[byte] |= ((mark & 0x3) << shift); +} + +static uint8_t bbt_get_block_mark(uint8_t *bbt, uint32_t block) +{ + unsigned int byte = block >> 2; + unsigned int shift = (block & 0x3) << 1; + + return (bbt[byte] >> shift) & 0x3; +} + +static int bbt_is_block_bad(uint8_t *bbt, uint32_t block) +{ + return bbt_get_block_mark(bbt, block) == BBT_MARK_GOOD ? 0 : 1; +} + /* Scan block for IBBT signature */ static int bch_find_ibbt_sig(struct nandi_controller *nandi, uint32_t block, int *bak, uint8_t *vers, -- 1.8.3.2