From f5f1f614bda83fae868d5634f86e0098162ceb3b Mon Sep 17 00:00:00 2001 From: pekon gupta Date: Tue, 19 Nov 2013 11:02:15 +0530 Subject: mtd: nand: omap: optimize chip->ecc.hwctl() for H/W ECC schemes chip->ecc.hwctl() is used for preparing the H/W controller before read/write NAND accesses (like assigning data-buf, enabling ECC scheme configs, etc.) Though all ECC schemes in OMAP NAND driver use GPMC controller for generating ECC syndrome (for both Read/Write accesses). But but in current code HAM1_ECC and BCHx_ECC schemes implement individual function to achieve this. This patch (1) removes omap_hwecc_init() and omap_hwecc_init_bch() as chip->ecc.hwctl will re-initializeGPMC before every read/write call. omap_hwecc_init_bch() -> omap_enable_ecc_bch() (2) merges the GPMC configuration code for all ECC schemes into single omap_enable_hwecc(), thus adding scalability for future ECC schemes. omap_enable_hwecc() + omap_enable_ecc_bch() -> omap_enable_hwecc() Signed-off-by: Pekon Gupta --- drivers/mtd/nand/omap_gpmc.c | 198 ++++++++++++------------------------------- 1 file changed, 56 insertions(+), 142 deletions(-) (limited to 'drivers') diff --git a/drivers/mtd/nand/omap_gpmc.c b/drivers/mtd/nand/omap_gpmc.c index 389c4de59a..48b2f75ed7 100644 --- a/drivers/mtd/nand/omap_gpmc.c +++ b/drivers/mtd/nand/omap_gpmc.c @@ -19,6 +19,8 @@ #define BADBLOCK_MARKER_LENGTH 2 #define SECTOR_BYTES 512 +#define ECCCLEAR (0x1 << 8) +#define ECCRESULTREG1 (0x1 << 0) static uint8_t cs; static __maybe_unused struct nand_ecclayout omap_ecclayout; @@ -60,21 +62,6 @@ int omap_spl_dev_ready(struct mtd_info *mtd) } #endif -/* - * omap_hwecc_init - Initialize the Hardware ECC for NAND flash in - * GPMC controller - * @mtd: MTD device structure - * - */ -static void __maybe_unused omap_hwecc_init(struct nand_chip *chip) -{ - /* - * Init ECC Control Register - * Clear all ECC | Enable Reg1 - */ - writel(ECCCLEAR | ECCRESULTREG1, &gpmc_cfg->ecc_control); - writel(ECCSIZE1 | ECCSIZE0 | ECCSIZE0SEL, &gpmc_cfg->ecc_size_config); -} /* * gen_true_ecc - This function will generate true ECC value, which @@ -191,38 +178,6 @@ static int __maybe_unused omap_calculate_ecc(struct mtd_info *mtd, return 0; } -/* - * omap_enable_ecc - This function enables the hardware ecc functionality - * @mtd: MTD device structure - * @mode: Read/Write mode - */ -static void __maybe_unused omap_enable_hwecc(struct mtd_info *mtd, int32_t mode) -{ - struct nand_chip *chip = mtd->priv; - uint32_t val, dev_width = (chip->options & NAND_BUSWIDTH_16) >> 1; - - switch (mode) { - case NAND_ECC_READ: - case NAND_ECC_WRITE: - /* Clear the ecc result registers, select ecc reg as 1 */ - writel(ECCCLEAR | ECCRESULTREG1, &gpmc_cfg->ecc_control); - - /* - * Size 0 = 0xFF, Size1 is 0xFF - both are 512 bytes - * tell all regs to generate size0 sized regs - * we just have a single ECC engine for all CS - */ - writel(ECCSIZE1 | ECCSIZE0 | ECCSIZE0SEL, - &gpmc_cfg->ecc_size_config); - val = (dev_width << 7) | (cs << 1) | (0x1); - writel(val, &gpmc_cfg->ecc_config); - break; - default: - printf("Error: Unrecognized Mode[%d]!\n", mode); - break; - } -} - /* * Generic BCH interface */ @@ -263,105 +218,65 @@ static __maybe_unused struct nand_bch_priv bch_priv = { }; /* - * omap_hwecc_init_bch - Initialize the BCH Hardware ECC for NAND flash in - * GPMC controller + * omap_enable_hwecc - configures GPMC as per ECC scheme before read/write * @mtd: MTD device structure * @mode: Read/Write mode */ __maybe_unused -static void omap_hwecc_init_bch(struct nand_chip *chip, int32_t mode) +static void omap_enable_hwecc(struct mtd_info *mtd, int32_t mode) { - uint32_t val; - uint32_t dev_width = (chip->options & NAND_BUSWIDTH_16) >> 1; - uint32_t unused_length = 0; - uint32_t wr_mode = BCH_WRAPMODE_6; - struct nand_bch_priv *bch = chip->priv; - - /* Clear the ecc result registers, select ecc reg as 1 */ - writel(ECCCLEAR | ECCRESULTREG1, &gpmc_cfg->ecc_control); - - if (bch->ecc_scheme == OMAP_ECC_BCH8_CODE_HW) { - wr_mode = BCH_WRAPMODE_1; - - switch (bch->nibbles) { - case ECC_BCH4_NIBBLES: - unused_length = 3; - break; - case ECC_BCH8_NIBBLES: - unused_length = 2; - break; - case ECC_BCH16_NIBBLES: - unused_length = 0; - break; - } - - /* - * This is ecc_size_config for ELM mode. Here we are using - * different settings for read and write access and also - * depending on BCH strength. - */ - switch (mode) { - case NAND_ECC_WRITE: - /* write access only setup eccsize1 config */ - val = ((unused_length + bch->nibbles) << 22); - break; - - case NAND_ECC_READ: - default: - /* - * by default eccsize0 selected for ecc1resultsize - * eccsize0 config. - */ - val = (bch->nibbles << 12); - /* eccsize1 config */ - val |= (unused_length << 22); - break; + struct nand_chip *nand = mtd->priv; + struct nand_bch_priv *bch = nand->priv; + unsigned int dev_width = (nand->options & NAND_BUSWIDTH_16) ? 1 : 0; + unsigned int ecc_algo = 0; + unsigned int bch_type = 0; + unsigned int eccsize1 = 0x00, eccsize0 = 0x00, bch_wrapmode = 0x00; + u32 ecc_size_config_val = 0; + u32 ecc_config_val = 0; + + /* configure GPMC for specific ecc-scheme */ + switch (bch->ecc_scheme) { + case OMAP_ECC_HAM1_CODE_SW: + return; + case OMAP_ECC_HAM1_CODE_HW: + ecc_algo = 0x0; + bch_type = 0x0; + bch_wrapmode = 0x00; + eccsize0 = 0xFF; + eccsize1 = 0xFF; + break; + case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW: + case OMAP_ECC_BCH8_CODE_HW: + ecc_algo = 0x1; + bch_type = 0x1; + if (mode == NAND_ECC_WRITE) { + bch_wrapmode = 0x01; + eccsize0 = 0; /* extra bits in nibbles per sector */ + eccsize1 = 28; /* OOB bits in nibbles per sector */ + } else { + bch_wrapmode = 0x01; + eccsize0 = 26; /* ECC bits in nibbles per sector */ + eccsize1 = 2; /* non-ECC bits in nibbles per sector */ } - } else { - /* - * This ecc_size_config setting is for BCH sw library. - * - * Note: we only support BCH8 currently with BCH sw library! - * Should be really easy to adobt to BCH4, however some omap3 - * have flaws with BCH4. - * - * Here we are using wrapping mode 6 both for reading and - * writing, with: - * size0 = 0 (no additional protected byte in spare area) - * size1 = 32 (skip 32 nibbles = 16 bytes per sector in - * spare area) - */ - val = (32 << 22) | (0 << 12); + break; + default: + return; } - /* ecc size configuration */ - writel(val, &gpmc_cfg->ecc_size_config); - - /* - * Configure the ecc engine in gpmc - * We assume 512 Byte sector pages for access to NAND. - */ - val = (1 << 16); /* enable BCH mode */ - val |= (bch->type << 12); /* setup BCH type */ - val |= (wr_mode << 8); /* setup wrapping mode */ - val |= (dev_width << 7); /* setup device width (16 or 8 bit) */ - val |= (cs << 1); /* setup chip select to work on */ - debug("set ECC_CONFIG=0x%08x\n", val); - writel(val, &gpmc_cfg->ecc_config); -} - -/* - * omap_enable_ecc_bch - This function enables the bch h/w ecc functionality - * @mtd: MTD device structure - * @mode: Read/Write mode - */ -__maybe_unused -static void omap_enable_ecc_bch(struct mtd_info *mtd, int32_t mode) -{ - struct nand_chip *chip = mtd->priv; - - omap_hwecc_init_bch(chip, mode); - /* enable ecc */ - writel((readl(&gpmc_cfg->ecc_config) | 0x1), &gpmc_cfg->ecc_config); + /* Clear ecc and enable bits */ + writel(ECCCLEAR | ECCRESULTREG1, &gpmc_cfg->ecc_control); + /* Configure ecc size for BCH */ + ecc_size_config_val = (eccsize1 << 22) | (eccsize0 << 12); + writel(ecc_size_config_val, &gpmc_cfg->ecc_size_config); + + /* Configure device details for BCH engine */ + ecc_config_val = ((ecc_algo << 16) | /* HAM1 | BCHx */ + (bch_type << 12) | /* BCH4/BCH8/BCH16 */ + (bch_wrapmode << 8) | /* wrap mode */ + (dev_width << 7) | /* bus width */ + (0x0 << 4) | /* number of sectors */ + (cs << 1) | /* ECC CS */ + (0x1)); /* enable ECC */ + writel(ecc_config_val, &gpmc_cfg->ecc_config); } /* @@ -835,7 +750,7 @@ static int omap_select_ecc_scheme(struct nand_chip *nand, nand->ecc.strength = 8; nand->ecc.size = SECTOR_BYTES; nand->ecc.bytes = 13; - nand->ecc.hwctl = omap_enable_ecc_bch; + nand->ecc.hwctl = omap_enable_hwecc; nand->ecc.correct = omap_correct_data_bch_sw; nand->ecc.calculate = omap_calculate_ecc_bch_sw; /* define ecc-layout */ @@ -852,7 +767,6 @@ static int omap_select_ecc_scheme(struct nand_chip *nand, ecclayout->oobfree[0].offset = i + BADBLOCK_MARKER_LENGTH; ecclayout->oobfree[0].length = oobsize - ecclayout->eccbytes - BADBLOCK_MARKER_LENGTH; - omap_hwecc_init_bch(nand, NAND_ECC_READ); bch->ecc_scheme = OMAP_ECC_BCH8_CODE_HW_DETECTION_SW; break; #else @@ -878,7 +792,7 @@ static int omap_select_ecc_scheme(struct nand_chip *nand, nand->ecc.strength = 8; nand->ecc.size = SECTOR_BYTES; nand->ecc.bytes = 14; - nand->ecc.hwctl = omap_enable_ecc_bch; + nand->ecc.hwctl = omap_enable_hwecc; nand->ecc.correct = omap_correct_data_bch; nand->ecc.calculate = omap_calculate_ecc_bch; nand->ecc.read_page = omap_read_page_bch; -- cgit v1.2.1 From 71a7f95600eeea03100af66e2f11498048f32cfe Mon Sep 17 00:00:00 2001 From: pekon gupta Date: Tue, 19 Nov 2013 11:02:16 +0530 Subject: mtd: nand: omap: optimize chip->ecc.calculate() for H/W ECC schemes chip->ecc.calculate() is used for calculating and fetching of ECC syndrome by processing the data passed during Read/Write accesses. All H/W based ECC schemes use GPMC controller to calculate ECC syndrome. But each BCHx_ECC scheme has its own implemetation of post-processing and fetching ECC syndrome from GPMC controller. This patch updates OMAP_ECC_BCH8_CODE_HW ECC scheme in following way: - merges multiple chip->calculate API for different ECC schemes omap_calculate_ecc() + omap_calculate_ecc_bch() + omap_calculate_ecc_bch_sw() ==> omap_calculate_ecc() - removes omap_ecc_disable() and instead uses it as inline. Signed-off-by: Pekon Gupta --- drivers/mtd/nand/omap_gpmc.c | 226 ++++++++++++------------------------------- 1 file changed, 63 insertions(+), 163 deletions(-) (limited to 'drivers') diff --git a/drivers/mtd/nand/omap_gpmc.c b/drivers/mtd/nand/omap_gpmc.c index 48b2f75ed7..ad5b0f17cc 100644 --- a/drivers/mtd/nand/omap_gpmc.c +++ b/drivers/mtd/nand/omap_gpmc.c @@ -21,7 +21,10 @@ #define SECTOR_BYTES 512 #define ECCCLEAR (0x1 << 8) #define ECCRESULTREG1 (0x1 << 0) - +#ifdef CONFIG_BCH +static u8 bch8_polynomial[] = {0xef, 0x51, 0x2e, 0x09, 0xed, 0x93, 0x9a, 0xc2, + 0x97, 0x79, 0xe5, 0x24, 0xb5}; +#endif static uint8_t cs; static __maybe_unused struct nand_ecclayout omap_ecclayout; @@ -142,42 +145,6 @@ static int __maybe_unused omap_correct_data(struct mtd_info *mtd, uint8_t *dat, return 0; } -/* - * omap_calculate_ecc - Generate non-inverted ECC bytes. - * - * Using noninverted ECC can be considered ugly since writing a blank - * page ie. padding will clear the ECC bytes. This is no problem as - * long nobody is trying to write data on the seemingly unused page. - * Reading an erased page will produce an ECC mismatch between - * generated and read ECC bytes that has to be dealt with separately. - * E.g. if page is 0xFF (fresh erased), and if HW ECC engine within GPMC - * is used, the result of read will be 0x0 while the ECC offsets of the - * spare area will be 0xFF which will result in an ECC mismatch. - * @mtd: MTD structure - * @dat: unused - * @ecc_code: ecc_code buffer - */ -static int __maybe_unused omap_calculate_ecc(struct mtd_info *mtd, - const uint8_t *dat, uint8_t *ecc_code) -{ - u_int32_t val; - - /* Start Reading from HW ECC1_Result = 0x200 */ - val = readl(&gpmc_cfg->ecc1_result); - - ecc_code[0] = val & 0xFF; - ecc_code[1] = (val >> 16) & 0xFF; - ecc_code[2] = ((val >> 8) & 0x0F) | ((val >> 20) & 0xF0); - - /* - * Stop reading anymore ECC vals and clear old results - * enable will be called if more reads are required - */ - writel(0x000, &gpmc_cfg->ecc_config); - - return 0; -} - /* * Generic BCH interface */ @@ -194,12 +161,7 @@ struct nand_bch_priv { #define ECC_BCH8 1 #define ECC_BCH16 2 -/* GPMC ecc engine settings */ -#define BCH_WRAPMODE_1 1 /* BCH wrap mode 1 */ -#define BCH_WRAPMODE_6 6 /* BCH wrap mode 6 */ - /* BCH nibbles for diff bch levels */ -#define NAND_ECC_HW_BCH ((uint8_t)(NAND_ECC_HW_OOB_FIRST) + 1) #define ECC_BCH4_NIBBLES 13 #define ECC_BCH8_NIBBLES 26 #define ECC_BCH16_NIBBLES 52 @@ -211,7 +173,6 @@ struct nand_bch_priv { * When some users with other BCH strength will exists this have to change! */ static __maybe_unused struct nand_bch_priv bch_priv = { - .mode = NAND_ECC_HW_BCH, .type = ECC_BCH8, .nibbles = ECC_BCH8_NIBBLES, .control = NULL @@ -280,57 +241,76 @@ static void omap_enable_hwecc(struct mtd_info *mtd, int32_t mode) } /* - * omap_ecc_disable - Disable H/W ECC calculation - * - * @mtd: MTD device structure - */ -static void __maybe_unused omap_ecc_disable(struct mtd_info *mtd) -{ - writel((readl(&gpmc_cfg->ecc_config) & ~0x1), &gpmc_cfg->ecc_config); -} - -/* - * BCH support using ELM module - */ -#ifdef CONFIG_NAND_OMAP_ELM -/* - * omap_read_bch8_result - Read BCH result for BCH8 level - * - * @mtd: MTD device structure - * @big_endian: When set read register 3 first - * @ecc_code: Read syndrome from BCH result registers + * omap_calculate_ecc - Read ECC result + * @mtd: MTD structure + * @dat: unused + * @ecc_code: ecc_code buffer + * Using noninverted ECC can be considered ugly since writing a blank + * page ie. padding will clear the ECC bytes. This is no problem as + * long nobody is trying to write data on the seemingly unused page. + * Reading an erased page will produce an ECC mismatch between + * generated and read ECC bytes that has to be dealt with separately. + * E.g. if page is 0xFF (fresh erased), and if HW ECC engine within GPMC + * is used, the result of read will be 0x0 while the ECC offsets of the + * spare area will be 0xFF which will result in an ECC mismatch. */ -static void omap_read_bch8_result(struct mtd_info *mtd, uint8_t big_endian, +static int omap_calculate_ecc(struct mtd_info *mtd, const uint8_t *dat, uint8_t *ecc_code) { - uint32_t *ptr; + struct nand_chip *chip = mtd->priv; + struct nand_bch_priv *bch = chip->priv; + uint32_t *ptr, val = 0; int8_t i = 0, j; - if (big_endian) { + switch (bch->ecc_scheme) { + case OMAP_ECC_HAM1_CODE_HW: + val = readl(&gpmc_cfg->ecc1_result); + ecc_code[0] = val & 0xFF; + ecc_code[1] = (val >> 16) & 0xFF; + ecc_code[2] = ((val >> 8) & 0x0F) | ((val >> 20) & 0xF0); + break; +#ifdef CONFIG_BCH + case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW: +#endif + case OMAP_ECC_BCH8_CODE_HW: ptr = &gpmc_cfg->bch_result_0_3[0].bch_result_x[3]; - ecc_code[i++] = readl(ptr) & 0xFF; + val = readl(ptr); + ecc_code[i++] = (val >> 0) & 0xFF; ptr--; for (j = 0; j < 3; j++) { - ecc_code[i++] = (readl(ptr) >> 24) & 0xFF; - ecc_code[i++] = (readl(ptr) >> 16) & 0xFF; - ecc_code[i++] = (readl(ptr) >> 8) & 0xFF; - ecc_code[i++] = readl(ptr) & 0xFF; + val = readl(ptr); + ecc_code[i++] = (val >> 24) & 0xFF; + ecc_code[i++] = (val >> 16) & 0xFF; + ecc_code[i++] = (val >> 8) & 0xFF; + ecc_code[i++] = (val >> 0) & 0xFF; ptr--; } - } else { - ptr = &gpmc_cfg->bch_result_0_3[0].bch_result_x[0]; - for (j = 0; j < 3; j++) { - ecc_code[i++] = readl(ptr) & 0xFF; - ecc_code[i++] = (readl(ptr) >> 8) & 0xFF; - ecc_code[i++] = (readl(ptr) >> 16) & 0xFF; - ecc_code[i++] = (readl(ptr) >> 24) & 0xFF; - ptr++; - } - ecc_code[i++] = readl(ptr) & 0xFF; - ecc_code[i++] = 0; /* 14th byte is always zero */ + break; + default: + return -EINVAL; + } + /* ECC scheme specific syndrome customizations */ + switch (bch->ecc_scheme) { + case OMAP_ECC_HAM1_CODE_HW: + break; +#ifdef CONFIG_BCH + case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW: + + for (i = 0; i < chip->ecc.bytes; i++) + *(ecc_code + i) = *(ecc_code + i) ^ + bch8_polynomial[i]; + break; +#endif + case OMAP_ECC_BCH8_CODE_HW: + ecc_code[chip->ecc.bytes - 1] = 0x00; + break; + default: + return -EINVAL; } + return 0; } +#ifdef CONFIG_NAND_OMAP_ELM /* * omap_rotate_ecc_bch - Rotate the syndrome bytes * @@ -366,35 +346,6 @@ static void omap_rotate_ecc_bch(struct mtd_info *mtd, uint8_t *calc_ecc, syndrome[i] = calc_ecc[j]; } -/* - * omap_calculate_ecc_bch - Read BCH ECC result - * - * @mtd: MTD structure - * @dat: unused - * @ecc_code: ecc_code buffer - */ -static int omap_calculate_ecc_bch(struct mtd_info *mtd, const uint8_t *dat, - uint8_t *ecc_code) -{ - struct nand_chip *chip = mtd->priv; - struct nand_bch_priv *bch = chip->priv; - uint8_t big_endian = 1; - int8_t ret = 0; - - if (bch->type == ECC_BCH8) - omap_read_bch8_result(mtd, big_endian, ecc_code); - else /* BCH4 and BCH16 currently not supported */ - ret = -1; - - /* - * Stop reading anymore ECC vals and clear old results - * enable will be called if more reads are required - */ - omap_ecc_disable(mtd); - - return ret; -} - /* * omap_fix_errors_bch - Correct bch error in the data * @@ -551,57 +502,6 @@ static int omap_read_page_bch(struct mtd_info *mtd, struct nand_chip *chip, * OMAP3 BCH8 support (with BCH library) */ #ifdef CONFIG_BCH -/* - * omap_calculate_ecc_bch_sw - Read BCH ECC result - * - * @mtd: MTD device structure - * @dat: The pointer to data on which ecc is computed (unused here) - * @ecc: The ECC output buffer - */ -static int omap_calculate_ecc_bch_sw(struct mtd_info *mtd, const uint8_t *dat, - uint8_t *ecc) -{ - int ret = 0; - size_t i; - unsigned long nsectors, val1, val2, val3, val4; - - nsectors = ((readl(&gpmc_cfg->ecc_config) >> 4) & 0x7) + 1; - - for (i = 0; i < nsectors; i++) { - /* Read hw-computed remainder */ - val1 = readl(&gpmc_cfg->bch_result_0_3[i].bch_result_x[0]); - val2 = readl(&gpmc_cfg->bch_result_0_3[i].bch_result_x[1]); - val3 = readl(&gpmc_cfg->bch_result_0_3[i].bch_result_x[2]); - val4 = readl(&gpmc_cfg->bch_result_0_3[i].bch_result_x[3]); - - /* - * Add constant polynomial to remainder, in order to get an ecc - * sequence of 0xFFs for a buffer filled with 0xFFs. - */ - *ecc++ = 0xef ^ (val4 & 0xFF); - *ecc++ = 0x51 ^ ((val3 >> 24) & 0xFF); - *ecc++ = 0x2e ^ ((val3 >> 16) & 0xFF); - *ecc++ = 0x09 ^ ((val3 >> 8) & 0xFF); - *ecc++ = 0xed ^ (val3 & 0xFF); - *ecc++ = 0x93 ^ ((val2 >> 24) & 0xFF); - *ecc++ = 0x9a ^ ((val2 >> 16) & 0xFF); - *ecc++ = 0xc2 ^ ((val2 >> 8) & 0xFF); - *ecc++ = 0x97 ^ (val2 & 0xFF); - *ecc++ = 0x79 ^ ((val1 >> 24) & 0xFF); - *ecc++ = 0xe5 ^ ((val1 >> 16) & 0xFF); - *ecc++ = 0x24 ^ ((val1 >> 8) & 0xFF); - *ecc++ = 0xb5 ^ (val1 & 0xFF); - } - - /* - * Stop reading anymore ECC vals and clear old results - * enable will be called if more reads are required - */ - omap_ecc_disable(mtd); - - return ret; -} - /** * omap_correct_data_bch_sw - Decode received data and correct errors * @mtd: MTD device structure @@ -752,7 +652,7 @@ static int omap_select_ecc_scheme(struct nand_chip *nand, nand->ecc.bytes = 13; nand->ecc.hwctl = omap_enable_hwecc; nand->ecc.correct = omap_correct_data_bch_sw; - nand->ecc.calculate = omap_calculate_ecc_bch_sw; + nand->ecc.calculate = omap_calculate_ecc; /* define ecc-layout */ ecclayout->eccbytes = nand->ecc.bytes * eccsteps; ecclayout->eccpos[0] = BADBLOCK_MARKER_LENGTH; @@ -794,7 +694,7 @@ static int omap_select_ecc_scheme(struct nand_chip *nand, nand->ecc.bytes = 14; nand->ecc.hwctl = omap_enable_hwecc; nand->ecc.correct = omap_correct_data_bch; - nand->ecc.calculate = omap_calculate_ecc_bch; + nand->ecc.calculate = omap_calculate_ecc; nand->ecc.read_page = omap_read_page_bch; /* define ecc-layout */ ecclayout->eccbytes = nand->ecc.bytes * eccsteps; -- cgit v1.2.1 From 6e562b1106ea6afc78752f50925e87e9dd14f8b4 Mon Sep 17 00:00:00 2001 From: pekon gupta Date: Tue, 19 Nov 2013 11:02:17 +0530 Subject: mtd: nand: omap: optimized chip->ecc.correct() for H/W ECC schemes chip->ecc.correct() is used for detecting and correcting bit-flips during read operations. In omap-nand driver it implemented as: (a) omap_correct_data(): for h/w based ECC_HAM1 scheme (b) omap_correct_data_bch() + CONFIG_NAND_OMAP_ECC_BCH8_CODE_HW_DETECTION_SW for ECC_BCH8 scheme using GPMC and software lib/bch.c (c) omap_correct_data_bch() + CONFIG_NAND_OMAP_ECC_BCH8_CODE_HW for ECC_BCH8 scheme using GPMC and ELM This patch updates (c) - checks for calc_ecc[]==0x00 so that error_correction is not required for known good pages. - adds scalability for other ECC_BCHx scheme by merging following omap_rotate_ecc_bch() + omap_fix_errors_bch() => omap_correct_data_bch() - fixing logic for bit-flip correction based on error_loc[count] Signed-off-by: Pekon Gupta --- drivers/mtd/nand/omap_gpmc.c | 161 +++++++++++++++++++------------------------ 1 file changed, 71 insertions(+), 90 deletions(-) (limited to 'drivers') diff --git a/drivers/mtd/nand/omap_gpmc.c b/drivers/mtd/nand/omap_gpmc.c index ad5b0f17cc..441b32144f 100644 --- a/drivers/mtd/nand/omap_gpmc.c +++ b/drivers/mtd/nand/omap_gpmc.c @@ -21,6 +21,9 @@ #define SECTOR_BYTES 512 #define ECCCLEAR (0x1 << 8) #define ECCRESULTREG1 (0x1 << 0) +/* 4 bit padding to make byte aligned, 56 = 52 + 4 */ +#define BCH4_BIT_PAD 4 + #ifdef CONFIG_BCH static u8 bch8_polynomial[] = {0xef, 0x51, 0x2e, 0x09, 0xed, 0x93, 0x9a, 0xc2, 0x97, 0x79, 0xe5, 0x24, 0xb5}; @@ -178,6 +181,23 @@ static __maybe_unused struct nand_bch_priv bch_priv = { .control = NULL }; +/* + * omap_reverse_list - re-orders list elements in reverse order [internal] + * @list: pointer to start of list + * @length: length of list +*/ +void omap_reverse_list(u8 *list, unsigned int length) +{ + unsigned int i, j; + unsigned int half_length = length / 2; + u8 tmp; + for (i = 0, j = length - 1; i < half_length; i++, j--) { + tmp = list[i]; + list[i] = list[j]; + list[j] = tmp; + } +} + /* * omap_enable_hwecc - configures GPMC as per ECC scheme before read/write * @mtd: MTD device structure @@ -311,77 +331,6 @@ static int omap_calculate_ecc(struct mtd_info *mtd, const uint8_t *dat, } #ifdef CONFIG_NAND_OMAP_ELM -/* - * omap_rotate_ecc_bch - Rotate the syndrome bytes - * - * @mtd: MTD device structure - * @calc_ecc: ECC read from ECC registers - * @syndrome: Rotated syndrome will be retuned in this array - * - */ -static void omap_rotate_ecc_bch(struct mtd_info *mtd, uint8_t *calc_ecc, - uint8_t *syndrome) -{ - struct nand_chip *chip = mtd->priv; - struct nand_bch_priv *bch = chip->priv; - uint8_t n_bytes = 0; - int8_t i, j; - - switch (bch->type) { - case ECC_BCH4: - n_bytes = 8; - break; - - case ECC_BCH16: - n_bytes = 28; - break; - - case ECC_BCH8: - default: - n_bytes = 13; - break; - } - - for (i = 0, j = (n_bytes-1); i < n_bytes; i++, j--) - syndrome[i] = calc_ecc[j]; -} - -/* - * omap_fix_errors_bch - Correct bch error in the data - * - * @mtd: MTD device structure - * @data: Data read from flash - * @error_count:Number of errors in data - * @error_loc: Locations of errors in the data - * - */ -static void omap_fix_errors_bch(struct mtd_info *mtd, uint8_t *data, - uint32_t error_count, uint32_t *error_loc) -{ - struct nand_chip *chip = mtd->priv; - struct nand_bch_priv *bch = chip->priv; - uint8_t count = 0; - uint32_t error_byte_pos; - uint32_t error_bit_mask; - uint32_t last_bit = (bch->nibbles * 4) - 1; - - /* Flip all bits as specified by the error location array. */ - /* FOR( each found error location flip the bit ) */ - for (count = 0; count < error_count; count++) { - if (error_loc[count] > last_bit) { - /* Remove the ECC spare bits from correction. */ - error_loc[count] -= (last_bit + 1); - /* Offset bit in data region */ - error_byte_pos = ((512 * 8) - - (error_loc[count]) - 1) / 8; - /* Error Bit mask */ - error_bit_mask = 0x1 << (error_loc[count] % 8); - /* Toggle the error bit to make the correction. */ - data[error_byte_pos] ^= error_bit_mask; - } - } -} - /* * omap_correct_data_bch - Compares the ecc read from nand spare area * with ECC registers values and corrects one bit error if it has occured @@ -398,40 +347,72 @@ static int omap_correct_data_bch(struct mtd_info *mtd, uint8_t *dat, { struct nand_chip *chip = mtd->priv; struct nand_bch_priv *bch = chip->priv; - uint8_t syndrome[28]; - uint32_t error_count = 0; + uint32_t eccbytes = chip->ecc.bytes; + uint32_t error_count = 0, error_max; uint32_t error_loc[8]; - uint32_t i, ecc_flag; + uint32_t i, ecc_flag = 0; + uint8_t count, err = 0; + uint32_t byte_pos, bit_pos; + /* check calculated ecc */ + for (i = 0; i < chip->ecc.bytes && !ecc_flag; i++) { + if (calc_ecc[i] != 0x00) + ecc_flag = 1; + } + if (!ecc_flag) + return 0; + + /* check for whether its a erased-page */ ecc_flag = 0; - for (i = 0; i < chip->ecc.bytes; i++) + for (i = 0; i < chip->ecc.bytes && !ecc_flag; i++) { if (read_ecc[i] != 0xff) ecc_flag = 1; - + } if (!ecc_flag) return 0; - elm_reset(); - elm_config((enum bch_level)(bch->type)); - /* * while reading ECC result we read it in big endian. * Hence while loading to ELM we have rotate to get the right endian. */ - omap_rotate_ecc_bch(mtd, calc_ecc, syndrome); - + switch (bch->ecc_scheme) { + case OMAP_ECC_BCH8_CODE_HW: + omap_reverse_list(calc_ecc, eccbytes - 1); + break; + default: + return -EINVAL; + } /* use elm module to check for errors */ - if (elm_check_error(syndrome, bch->nibbles, &error_count, - error_loc) != 0) { - printf("ECC: uncorrectable.\n"); - return -1; + elm_config((enum bch_level)(bch->type)); + if (elm_check_error(calc_ecc, bch->nibbles, &error_count, error_loc)) { + printf("nand: error: uncorrectable ECC errors\n"); + return -EINVAL; } - /* correct bch error */ - if (error_count > 0) - omap_fix_errors_bch(mtd, dat, error_count, error_loc); - - return 0; + for (count = 0; count < error_count; count++) { + switch (bch->type) { + case ECC_BCH8: + /* 14th byte in ECC is reserved to match ROM layout */ + error_max = SECTOR_BYTES + (eccbytes - 1); + break; + default: + return -EINVAL; + } + byte_pos = error_max - (error_loc[count] / 8) - 1; + bit_pos = error_loc[count] % 8; + if (byte_pos < SECTOR_BYTES) { + dat[byte_pos] ^= 1 << bit_pos; + printf("nand: bit-flip corrected @data=%d\n", byte_pos); + } else if (byte_pos < error_max) { + read_ecc[byte_pos - SECTOR_BYTES] = 1 << bit_pos; + printf("nand: bit-flip corrected @oob=%d\n", byte_pos - + SECTOR_BYTES); + } else { + err = -EBADMSG; + printf("nand: error: invalid bit-flip location\n"); + } + } + return (err) ? err : error_count; } /** -- cgit v1.2.1 From 51d192c40daa2b58cfc96c772799d9c632df33e3 Mon Sep 17 00:00:00 2001 From: pekon gupta Date: Fri, 22 Nov 2013 16:53:28 +0530 Subject: mtd: nand: omap: merge duplicate GPMC data from different arch-xx headers into common omap_gpmc.h Each SoC platform (AM33xx, OMAP3, OMAP4, OMAP5) has its own copy of GPMC related defines and declarations scattered in SoC platform specific header files like include/asm/arch-xx/cpu.h However, GPMC hardware remains same across all platforms thus this patch merges GPMC data scattered across different arch-xx specific header files into single header file include/asm/arch/omap_gpmc.h Build tested using: ./MAKEALL -s am33xx -s omap3 -s omap4 -s omap5 Signed-off-by: Pekon Gupta --- drivers/mtd/nand/omap_elm.c | 2 +- drivers/mtd/nand/omap_gpmc.c | 1 - 2 files changed, 1 insertion(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/mtd/nand/omap_elm.c b/drivers/mtd/nand/omap_elm.c index 2aa7807f3e..64dca4fe98 100644 --- a/drivers/mtd/nand/omap_elm.c +++ b/drivers/mtd/nand/omap_elm.c @@ -16,9 +16,9 @@ #include #include #include -#include #include #include +#include #define ELM_DEFAULT_POLY (0) diff --git a/drivers/mtd/nand/omap_gpmc.c b/drivers/mtd/nand/omap_gpmc.c index 441b32144f..b54e39e1cd 100644 --- a/drivers/mtd/nand/omap_gpmc.c +++ b/drivers/mtd/nand/omap_gpmc.c @@ -9,7 +9,6 @@ #include #include #include -#include #include #include #include -- cgit v1.2.1 From 6aff05098864233caf9d24cb020e67b00ada4e3e Mon Sep 17 00:00:00 2001 From: pekon gupta Date: Fri, 22 Nov 2013 16:53:29 +0530 Subject: mtd: nand: omap: move omap_gpmc.h from arch/arm/include/asm to drivers/mtd/nand omap_gpmc.h is a generic header used by OMAP NAND driver for all TI platfoms. Hence this file should be present in generic folder instead of architecture specific include folder. Build tested using: ./MAKEALL -s am33xx -s omap3 -s omap4 -s omap5 Signed-off-by: Pekon Gupta --- drivers/mtd/nand/omap_elm.c | 2 +- drivers/mtd/nand/omap_gpmc.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/mtd/nand/omap_elm.c b/drivers/mtd/nand/omap_elm.c index 64dca4fe98..55a631deb4 100644 --- a/drivers/mtd/nand/omap_elm.c +++ b/drivers/mtd/nand/omap_elm.c @@ -16,7 +16,7 @@ #include #include #include -#include +#include #include #include diff --git a/drivers/mtd/nand/omap_gpmc.c b/drivers/mtd/nand/omap_gpmc.c index b54e39e1cd..452e40f04e 100644 --- a/drivers/mtd/nand/omap_gpmc.c +++ b/drivers/mtd/nand/omap_gpmc.c @@ -9,7 +9,7 @@ #include #include #include -#include +#include #include #include #include -- cgit v1.2.1 From 2eda892f00fbcf46143326f72e8ac5b472bd225a Mon Sep 17 00:00:00 2001 From: pekon gupta Date: Fri, 22 Nov 2013 16:53:30 +0530 Subject: mtd: nand: omap: move omap_elm.h from arch/arm/include/asm to drivers/mtd/nand omap_elm.h is a generic header used by OMAP ELM driver for all TI platfoms. Hence this file should be present in generic folder instead of architecture specific include folder. Build tested using: ./MAKEALL -s am33xx -s omap3 -s omap4 -s omap5 Signed-off-by: Pekon Gupta --- drivers/mtd/nand/omap_elm.c | 2 +- drivers/mtd/nand/omap_gpmc.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/mtd/nand/omap_elm.c b/drivers/mtd/nand/omap_elm.c index 55a631deb4..47b1f1bfe2 100644 --- a/drivers/mtd/nand/omap_elm.c +++ b/drivers/mtd/nand/omap_elm.c @@ -17,7 +17,7 @@ #include #include #include -#include +#include #include #define ELM_DEFAULT_POLY (0) diff --git a/drivers/mtd/nand/omap_gpmc.c b/drivers/mtd/nand/omap_gpmc.c index 452e40f04e..881a63618c 100644 --- a/drivers/mtd/nand/omap_gpmc.c +++ b/drivers/mtd/nand/omap_gpmc.c @@ -14,7 +14,7 @@ #include #include #include -#include +#include #define BADBLOCK_MARKER_LENGTH 2 #define SECTOR_BYTES 512 -- cgit v1.2.1