From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754469AbaCYIrN (ORCPT ); Tue, 25 Mar 2014 04:47:13 -0400 Received: from mail-we0-f169.google.com ([74.125.82.169]:58575 "EHLO mail-we0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752957AbaCYIVE (ORCPT ); Tue, 25 Mar 2014 04:21:04 -0400 From: Lee Jones To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: lee.jones@linaro.org, kernel@stlinux.com, computersforpeace@gmail.com, linux-mtd@lists.infradead.org, dwmw2@infradead.org, angus.clark@st.com, pekon@ti.com Subject: [RFC 24/47] mtd: nand: stm_nand_bch: find IBBT signature Date: Tue, 25 Mar 2014 08:19:41 +0000 Message-Id: <1395735604-26706-25-git-send-email-lee.jones@linaro.org> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1395735604-26706-1-git-send-email-lee.jones@linaro.org> References: <1395735604-26706-1-git-send-email-lee.jones@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Scan block for IBBT signature, either "Bbt0" or "1tbB" from pre-specified data block. Signed-off-by: Lee Jones --- drivers/mtd/nand/stm_nand_bch.c | 91 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 91 insertions(+) diff --git a/drivers/mtd/nand/stm_nand_bch.c b/drivers/mtd/nand/stm_nand_bch.c index 6323590..5bcaabbc 100644 --- a/drivers/mtd/nand/stm_nand_bch.c +++ b/drivers/mtd/nand/stm_nand_bch.c @@ -43,6 +43,37 @@ static int bch_ecc_sizes[] = { [BCH_NO_ECC] = 0, }; +/* + * Inband Bad Block Table (IBBT) + */ +#define NAND_IBBT_NBLOCKS 4 +#define NAND_IBBT_SIGLEN 4 +#define NAND_IBBT_PRIMARY 0 +#define NAND_IBBT_MIRROR 1 +#define NAND_IBBT_SCHEMA 0x10 +#define NAND_IBBT_BCH_SCHEMA 0x10 + +static uint8_t ibbt_sigs[2][NAND_IBBT_SIGLEN] = { + {'B', 'b', 't', '0'}, + {'1', 't', 'b', 'B'}, +}; + +/* IBBT header */ +struct nand_ibbt_header { + uint8_t signature[4]; /* "Bbt0" or "1tbB" signature */ + uint8_t version; /* BBT version ("age") */ + uint8_t reserved[3]; /* padding */ + uint8_t schema[4]; /* "base" schema (x4) */ +} __packed; + +/* Extend IBBT header with some stm-nand-bch niceties */ +struct nand_ibbt_bch_header { + struct nand_ibbt_header base; + uint8_t schema[4]; /* "private" schema (x4) */ + uint8_t ecc_size[4]; /* ECC bytes (0, 32, 54) (x4) */ + char author[64]; /* Arbitrary string for S/W to use */ +} __packed; + /* Bad Block Table (BBT) */ struct nandi_bbt_info { uint32_t bbt_size; /* Size of bad-block table */ @@ -464,6 +495,66 @@ static uint8_t bch_write_page(struct nandi_controller *nandi, return status; } +/* Scan block for IBBT signature */ +static int bch_find_ibbt_sig(struct nandi_controller *nandi, + uint32_t block, int *bak, uint8_t *vers, + char *author) +{ + struct mtd_info *mtd = &nandi->info.mtd; + struct nand_ibbt_bch_header *ibbt_header; + loff_t offs; + uint8_t *buf = nandi->page_buf; + int match_sig; + unsigned int b; + unsigned int i; + + nandi->cached_page = -1; + + /* Load last page of block */ + offs = (loff_t)block << nandi->block_shift; + offs += mtd->erasesize - mtd->writesize; + if (bch_read_page(nandi, offs, buf) < 0) { + dev_info(nandi->dev, + "Uncorrectable ECC error while scanning BBT signature at block %u [0x%012llx]\n", + block, offs); + return 0; + } + ibbt_header = (struct nand_ibbt_bch_header *)buf; + + /* Test IBBT signature */ + match_sig = 0; + for (b = 0; b < 2 && !match_sig; b++) { + match_sig = 1; + for (i = 0; i < NAND_IBBT_SIGLEN; i++) { + if (ibbt_header->base.signature[i] != ibbt_sigs[b][i]) { + match_sig = 0; + break; + } + } + + } + + if (!match_sig) + return 0; /* Failed to match IBBT signature */ + + /* Test IBBT schema */ + for (i = 0; i < 4; i++) + if (ibbt_header->base.schema[i] != NAND_IBBT_SCHEMA) + return 0; + + /* Test IBBT BCH schema */ + for (i = 0; i < 4; i++) + if (ibbt_header->schema[i] != NAND_IBBT_BCH_SCHEMA) + return 0; + + /* We have a match */ + *vers = ibbt_header->base.version; + *bak = b - 1; + strncpy(author, ibbt_header->author, 64); + + return 1; +} + /* * Initialisation */ -- 1.8.3.2