From da3bc42c1becfde026656df50ad155239d4e1a6b Mon Sep 17 00:00:00 2001 From: Boris BREZILLON Date: Sun, 30 Nov 2014 19:10:29 +0100 Subject: mtd: nand: gpmi: add proper raw access support Several MTD users (either in user or kernel space) expect a valid raw access support to NAND chip devices. This is particularly true for testing tools which are often touching the data stored in a NAND chip in raw mode to artificially generate errors. The GPMI drivers do not implemenent raw access functions, and thus rely on default HW_ECC scheme implementation. The default implementation consider the data and OOB area as properly separated in their respective NAND section, which is not true for the GPMI controller. In this driver/controller some OOB data are stored at the beginning of the NAND data area (these data are called metadata in the driver), then ECC bytes are interleaved with data chunk (which is similar to the HW_ECC_SYNDROME scheme), and eventually the remaining bytes are used as OOB data. Signed-off-by: Boris Brezillon Tested-by: Huang Shijie Signed-off-by: Brian Norris --- drivers/mtd/nand/gpmi-nand/gpmi-nand.c | 183 +++++++++++++++++++++++++++++++++ 1 file changed, 183 insertions(+) (limited to 'drivers/mtd/nand/gpmi-nand/gpmi-nand.c') diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c index 959cb9b7031..987de1e3821 100644 --- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c +++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c @@ -791,6 +791,7 @@ static void gpmi_free_dma_buffer(struct gpmi_nand_data *this) this->page_buffer_phys); kfree(this->cmd_buffer); kfree(this->data_buffer_dma); + kfree(this->raw_buffer); this->cmd_buffer = NULL; this->data_buffer_dma = NULL; @@ -837,6 +838,9 @@ static int gpmi_alloc_dma_buffer(struct gpmi_nand_data *this) if (!this->page_buffer_virt) goto error_alloc; + this->raw_buffer = kzalloc(mtd->writesize + mtd->oobsize, GFP_KERNEL); + if (!this->raw_buffer) + goto error_alloc; /* Slice up the page buffer. */ this->payload_virt = this->page_buffer_virt; @@ -1347,6 +1351,183 @@ gpmi_ecc_write_oob(struct mtd_info *mtd, struct nand_chip *chip, int page) return status & NAND_STATUS_FAIL ? -EIO : 0; } +/* + * This function reads a NAND page without involving the ECC engine (no HW + * ECC correction). + * The tricky part in the GPMI/BCH controller is that it stores ECC bits + * inline (interleaved with payload DATA), and do not align data chunk on + * byte boundaries. + * We thus need to take care moving the payload data and ECC bits stored in the + * page into the provided buffers, which is why we're using gpmi_copy_bits. + * + * See set_geometry_by_ecc_info inline comments to have a full description + * of the layout used by the GPMI controller. + */ +static int gpmi_ecc_read_page_raw(struct mtd_info *mtd, + struct nand_chip *chip, uint8_t *buf, + int oob_required, int page) +{ + struct gpmi_nand_data *this = chip->priv; + struct bch_geometry *nfc_geo = &this->bch_geometry; + int eccsize = nfc_geo->ecc_chunk_size; + int eccbits = nfc_geo->ecc_strength * nfc_geo->gf_len; + u8 *tmp_buf = this->raw_buffer; + size_t src_bit_off; + size_t oob_bit_off; + size_t oob_byte_off; + uint8_t *oob = chip->oob_poi; + int step; + + chip->read_buf(mtd, tmp_buf, + mtd->writesize + mtd->oobsize); + + /* + * If required, swap the bad block marker and the data stored in the + * metadata section, so that we don't wrongly consider a block as bad. + * + * See the layout description for a detailed explanation on why this + * is needed. + */ + if (this->swap_block_mark) { + u8 swap = tmp_buf[0]; + + tmp_buf[0] = tmp_buf[mtd->writesize]; + tmp_buf[mtd->writesize] = swap; + } + + /* + * Copy the metadata section into the oob buffer (this section is + * guaranteed to be aligned on a byte boundary). + */ + if (oob_required) + memcpy(oob, tmp_buf, nfc_geo->metadata_size); + + oob_bit_off = nfc_geo->metadata_size * 8; + src_bit_off = oob_bit_off; + + /* Extract interleaved payload data and ECC bits */ + for (step = 0; step < nfc_geo->ecc_chunk_count; step++) { + if (buf) + gpmi_copy_bits(buf, step * eccsize * 8, + tmp_buf, src_bit_off, + eccsize * 8); + src_bit_off += eccsize * 8; + + /* Align last ECC block to align a byte boundary */ + if (step == nfc_geo->ecc_chunk_count - 1 && + (oob_bit_off + eccbits) % 8) + eccbits += 8 - ((oob_bit_off + eccbits) % 8); + + if (oob_required) + gpmi_copy_bits(oob, oob_bit_off, + tmp_buf, src_bit_off, + eccbits); + + src_bit_off += eccbits; + oob_bit_off += eccbits; + } + + if (oob_required) { + oob_byte_off = oob_bit_off / 8; + + if (oob_byte_off < mtd->oobsize) + memcpy(oob + oob_byte_off, + tmp_buf + mtd->writesize + oob_byte_off, + mtd->oobsize - oob_byte_off); + } + + return 0; +} + +/* + * This function writes a NAND page without involving the ECC engine (no HW + * ECC generation). + * The tricky part in the GPMI/BCH controller is that it stores ECC bits + * inline (interleaved with payload DATA), and do not align data chunk on + * byte boundaries. + * We thus need to take care moving the OOB area at the right place in the + * final page, which is why we're using gpmi_copy_bits. + * + * See set_geometry_by_ecc_info inline comments to have a full description + * of the layout used by the GPMI controller. + */ +static int gpmi_ecc_write_page_raw(struct mtd_info *mtd, + struct nand_chip *chip, + const uint8_t *buf, + int oob_required) +{ + struct gpmi_nand_data *this = chip->priv; + struct bch_geometry *nfc_geo = &this->bch_geometry; + int eccsize = nfc_geo->ecc_chunk_size; + int eccbits = nfc_geo->ecc_strength * nfc_geo->gf_len; + u8 *tmp_buf = this->raw_buffer; + uint8_t *oob = chip->oob_poi; + size_t dst_bit_off; + size_t oob_bit_off; + size_t oob_byte_off; + int step; + + /* + * Initialize all bits to 1 in case we don't have a buffer for the + * payload or oob data in order to leave unspecified bits of data + * to their initial state. + */ + if (!buf || !oob_required) + memset(tmp_buf, 0xff, mtd->writesize + mtd->oobsize); + + /* + * First copy the metadata section (stored in oob buffer) at the + * beginning of the page, as imposed by the GPMI layout. + */ + memcpy(tmp_buf, oob, nfc_geo->metadata_size); + oob_bit_off = nfc_geo->metadata_size * 8; + dst_bit_off = oob_bit_off; + + /* Interleave payload data and ECC bits */ + for (step = 0; step < nfc_geo->ecc_chunk_count; step++) { + if (buf) + gpmi_copy_bits(tmp_buf, dst_bit_off, + buf, step * eccsize * 8, eccsize * 8); + dst_bit_off += eccsize * 8; + + /* Align last ECC block to align a byte boundary */ + if (step == nfc_geo->ecc_chunk_count - 1 && + (oob_bit_off + eccbits) % 8) + eccbits += 8 - ((oob_bit_off + eccbits) % 8); + + if (oob_required) + gpmi_copy_bits(tmp_buf, dst_bit_off, + oob, oob_bit_off, eccbits); + + dst_bit_off += eccbits; + oob_bit_off += eccbits; + } + + oob_byte_off = oob_bit_off / 8; + + if (oob_required && oob_byte_off < mtd->oobsize) + memcpy(tmp_buf + mtd->writesize + oob_byte_off, + oob + oob_byte_off, mtd->oobsize - oob_byte_off); + + /* + * If required, swap the bad block marker and the first byte of the + * metadata section, so that we don't modify the bad block marker. + * + * See the layout description for a detailed explanation on why this + * is needed. + */ + if (this->swap_block_mark) { + u8 swap = tmp_buf[0]; + + tmp_buf[0] = tmp_buf[mtd->writesize]; + tmp_buf[mtd->writesize] = swap; + } + + chip->write_buf(mtd, tmp_buf, mtd->writesize + mtd->oobsize); + + return 0; +} + static int gpmi_block_markbad(struct mtd_info *mtd, loff_t ofs) { struct nand_chip *chip = mtd->priv; @@ -1664,6 +1845,8 @@ static int gpmi_init_last(struct gpmi_nand_data *this) ecc->write_page = gpmi_ecc_write_page; ecc->read_oob = gpmi_ecc_read_oob; ecc->write_oob = gpmi_ecc_write_oob; + ecc->read_page_raw = gpmi_ecc_read_page_raw; + ecc->write_page_raw = gpmi_ecc_write_page_raw; ecc->mode = NAND_ECC_HW; ecc->size = bch_geo->ecc_chunk_size; ecc->strength = bch_geo->ecc_strength; -- cgit v1.2.3-70-g09d2 From 7ca94e07fe8ccbaca9ecb59f388ab8dd93c73e88 Mon Sep 17 00:00:00 2001 From: Boris BREZILLON Date: Sun, 30 Nov 2014 19:10:30 +0100 Subject: mtd: nand: gpmi: add raw oob access functions Implement raw OOB access functions to retrieve OOB bytes when accessing the NAND in raw mode. Signed-off-by: Boris Brezillon Tested-by: Huang Shijie Signed-off-by: Brian Norris --- drivers/mtd/nand/gpmi-nand/gpmi-nand.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'drivers/mtd/nand/gpmi-nand/gpmi-nand.c') diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c index 987de1e3821..4f3851a24bb 100644 --- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c +++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c @@ -1528,6 +1528,22 @@ static int gpmi_ecc_write_page_raw(struct mtd_info *mtd, return 0; } +static int gpmi_ecc_read_oob_raw(struct mtd_info *mtd, struct nand_chip *chip, + int page) +{ + chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page); + + return gpmi_ecc_read_page_raw(mtd, chip, NULL, 1, page); +} + +static int gpmi_ecc_write_oob_raw(struct mtd_info *mtd, struct nand_chip *chip, + int page) +{ + chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0, page); + + return gpmi_ecc_write_page_raw(mtd, chip, NULL, 1); +} + static int gpmi_block_markbad(struct mtd_info *mtd, loff_t ofs) { struct nand_chip *chip = mtd->priv; @@ -1847,6 +1863,8 @@ static int gpmi_init_last(struct gpmi_nand_data *this) ecc->write_oob = gpmi_ecc_write_oob; ecc->read_page_raw = gpmi_ecc_read_page_raw; ecc->write_page_raw = gpmi_ecc_write_page_raw; + ecc->read_oob_raw = gpmi_ecc_read_oob_raw; + ecc->write_oob_raw = gpmi_ecc_write_oob_raw; ecc->mode = NAND_ECC_HW; ecc->size = bch_geo->ecc_chunk_size; ecc->strength = bch_geo->ecc_strength; -- cgit v1.2.3-70-g09d2