diff options
Diffstat (limited to 'drivers/mtd/nand/raw/nand_base.c')
-rw-r--r-- | drivers/mtd/nand/raw/nand_base.c | 85 |
1 files changed, 56 insertions, 29 deletions
diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c index bbdcfbe643..ccbd42a427 100644 --- a/drivers/mtd/nand/raw/nand_base.c +++ b/drivers/mtd/nand/raw/nand_base.c @@ -1207,21 +1207,36 @@ static int nand_lp_exec_read_page_op(struct nand_chip *chip, unsigned int page, return nand_exec_op(chip, &op); } +static unsigned int rawnand_last_page_of_lun(unsigned int pages_per_lun, unsigned int lun) +{ + /* lun is expected to be very small */ + return (lun * pages_per_lun) + pages_per_lun - 1; +} + static void rawnand_cap_cont_reads(struct nand_chip *chip) { struct nand_memory_organization *memorg; - unsigned int pages_per_lun, first_lun, last_lun; + unsigned int ppl, first_lun, last_lun; memorg = nanddev_get_memorg(&chip->base); - pages_per_lun = memorg->pages_per_eraseblock * memorg->eraseblocks_per_lun; - first_lun = chip->cont_read.first_page / pages_per_lun; - last_lun = chip->cont_read.last_page / pages_per_lun; + ppl = memorg->pages_per_eraseblock * memorg->eraseblocks_per_lun; + first_lun = chip->cont_read.first_page / ppl; + last_lun = chip->cont_read.last_page / ppl; /* Prevent sequential cache reads across LUN boundaries */ if (first_lun != last_lun) - chip->cont_read.pause_page = first_lun * pages_per_lun + pages_per_lun - 1; + chip->cont_read.pause_page = rawnand_last_page_of_lun(ppl, first_lun); else chip->cont_read.pause_page = chip->cont_read.last_page; + + if (chip->cont_read.first_page == chip->cont_read.pause_page) { + chip->cont_read.first_page++; + chip->cont_read.pause_page = min(chip->cont_read.last_page, + rawnand_last_page_of_lun(ppl, first_lun + 1)); + } + + if (chip->cont_read.first_page >= chip->cont_read.last_page) + chip->cont_read.ongoing = false; } static int nand_lp_exec_cont_read_page_op(struct nand_chip *chip, unsigned int page, @@ -1288,12 +1303,11 @@ static int nand_lp_exec_cont_read_page_op(struct nand_chip *chip, unsigned int p if (!chip->cont_read.ongoing) return 0; - if (page == chip->cont_read.pause_page && - page != chip->cont_read.last_page) { - chip->cont_read.first_page = chip->cont_read.pause_page + 1; - rawnand_cap_cont_reads(chip); - } else if (page == chip->cont_read.last_page) { + if (page == chip->cont_read.last_page) { chip->cont_read.ongoing = false; + } else if (page == chip->cont_read.pause_page) { + chip->cont_read.first_page++; + rawnand_cap_cont_reads(chip); } return 0; @@ -3460,30 +3474,36 @@ static void rawnand_enable_cont_reads(struct nand_chip *chip, unsigned int page, u32 readlen, int col) { struct mtd_info *mtd = nand_to_mtd(chip); - unsigned int end_page, end_col; + unsigned int first_page, last_page; chip->cont_read.ongoing = false; if (!chip->controller->supported_op.cont_read) return; - end_page = DIV_ROUND_UP(col + readlen, mtd->writesize); - end_col = (col + readlen) % mtd->writesize; + /* + * Don't bother making any calculations if the length is too small. + * Side effect: avoids possible integer underflows below. + */ + if (readlen < (2 * mtd->writesize)) + return; + /* Derive the page where continuous read should start (the first full page read) */ + first_page = page; if (col) - page++; + first_page++; - if (end_col && end_page) - end_page--; + /* Derive the page where continuous read should stop (the last full page read) */ + last_page = page + ((col + readlen) / mtd->writesize) - 1; - if (page + 1 > end_page) - return; - - chip->cont_read.first_page = page; - chip->cont_read.last_page = end_page; - chip->cont_read.ongoing = true; - - rawnand_cap_cont_reads(chip); + /* Configure and enable continuous read when suitable */ + if (first_page < last_page) { + chip->cont_read.first_page = first_page; + chip->cont_read.last_page = last_page; + chip->cont_read.ongoing = true; + /* May reset the ongoing flag */ + rawnand_cap_cont_reads(chip); + } } static void rawnand_cont_read_skip_first_page(struct nand_chip *chip, unsigned int page) @@ -3492,10 +3512,7 @@ static void rawnand_cont_read_skip_first_page(struct nand_chip *chip, unsigned i return; chip->cont_read.first_page++; - if (chip->cont_read.first_page == chip->cont_read.pause_page) - chip->cont_read.first_page++; - if (chip->cont_read.first_page >= chip->cont_read.last_page) - chip->cont_read.ongoing = false; + rawnand_cap_cont_reads(chip); } /** @@ -3571,7 +3588,8 @@ static int nand_do_read_ops(struct nand_chip *chip, loff_t from, oob = ops->oobbuf; oob_required = oob ? 1 : 0; - rawnand_enable_cont_reads(chip, page, readlen, col); + if (likely(ops->mode != MTD_OPS_RAW)) + rawnand_enable_cont_reads(chip, page, readlen, col); while (1) { struct mtd_ecc_stats ecc_stats = mtd->ecc_stats; @@ -5189,6 +5207,15 @@ static void rawnand_late_check_supported_ops(struct nand_chip *chip) if (!nand_has_exec_op(chip)) return; + /* + * For now, continuous reads can only be used with the core page helpers. + * This can be extended later. + */ + if (!(chip->ecc.read_page == nand_read_page_hwecc || + chip->ecc.read_page == nand_read_page_syndrome || + chip->ecc.read_page == nand_read_page_swecc)) + return; + rawnand_check_cont_read_support(chip); } |