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author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-11 08:35:34 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-11 08:35:34 -0700 |
commit | e413a19a8ef49ae3b76310bb569dabe66b22f5a3 (patch) | |
tree | f171d40fd0ec69296458173d7ec470339f93f53b /drivers/mtd/nand/nand_base.c | |
parent | 8d0304e69dc960ae7683943ac5b9c4c685d409d7 (diff) | |
parent | f1900c79633e9ed757319e63aefb8e29443ea35e (diff) | |
download | op-kernel-dev-e413a19a8ef49ae3b76310bb569dabe66b22f5a3.zip op-kernel-dev-e413a19a8ef49ae3b76310bb569dabe66b22f5a3.tar.gz |
Merge tag 'for-linus-20140610' of git://git.infradead.org/linux-mtd
Pull MTD updates from Brian Norris:
- refactor m25p80.c driver for use as a general SPI NOR framework for
other drivers which may speak to SPI NOR flash without providing full
SPI support (i.e., not part of drivers/spi/)
- new Freescale QuadSPI driver (utilizing new SPI NOR framework)
- updates for the STMicro "FSM" SPI NOR driver
- fix sync/flush behavior on mtd_blkdevs
- fixup subpage write support on a few NAND drivers
- correct the MTD OOB test for odd-sized OOB areas
- add BCH-16 support for OMAP NAND
- fix warnings and trivial refactoring
- utilize new ECC DT bindings in pxa3xx NAND driver
- new LPDDR NVM driver
- address a few assorted bugs caught by Coverity
- add new imx6sx support for GPMI NAND
- use a bounce buffer for NAND when non-DMA-able buffers are used
* tag 'for-linus-20140610' of git://git.infradead.org/linux-mtd: (77 commits)
mtd: gpmi: add gpmi support for imx6sx
mtd: maps: remove check for CONFIG_MTD_SUPERH_RESERVE
mtd: bf5xx_nand: use the managed version of kzalloc
mtd: pxa3xx_nand: make the driver work on big-endian systems
mtd: nand: omap: fix omap_calculate_ecc_bch() for-loop error
mtd: nand: r852: correct write_buf loop bounds
mtd: nand_bbt: handle error case for nand_create_badblock_pattern()
mtd: nand_bbt: remove unused variable
mtd: maps: sc520cdp: fix warnings
mtd: slram: fix unused variable warning
mtd: pfow: remove unused variable
mtd: lpddr: fix Kconfig dependency, for I/O accessors
mtd: nand: pxa3xx: Add supported ECC strength and step size to the DT binding
mtd: nand: pxa3xx: Use ECC strength and step size devicetree binding
mtd: nand: pxa3xx: Clean pxa_ecc_init() error handling
mtd: nand: Warn the user if the selected ECC strength is too weak
mtd: nand: omap: Documentation: How to select correct ECC scheme for your device ?
mtd: nand: omap: add support for BCH16_ECC - NAND driver updates
mtd: nand: omap: add support for BCH16_ECC - ELM driver updates
mtd: nand: omap: add support for BCH16_ECC - GPMC driver updates
...
Diffstat (limited to 'drivers/mtd/nand/nand_base.c')
-rw-r--r-- | drivers/mtd/nand/nand_base.c | 104 |
1 files changed, 86 insertions, 18 deletions
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index 9d01c4d..41167e9 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -37,6 +37,7 @@ #include <linux/err.h> #include <linux/sched.h> #include <linux/slab.h> +#include <linux/mm.h> #include <linux/types.h> #include <linux/mtd/mtd.h> #include <linux/mtd/nand.h> @@ -1204,8 +1205,7 @@ static int nand_read_subpage(struct mtd_info *mtd, struct nand_chip *chip, * ecc.pos. Let's make sure that there are no gaps in ECC positions. */ for (i = 0; i < eccfrag_len - 1; i++) { - if (eccpos[i + start_step * chip->ecc.bytes] + 1 != - eccpos[i + start_step * chip->ecc.bytes + 1]) { + if (eccpos[i + index] + 1 != eccpos[i + index + 1]) { gaps = 1; break; } @@ -1501,6 +1501,7 @@ static int nand_do_read_ops(struct mtd_info *mtd, loff_t from, mtd->oobavail : mtd->oobsize; uint8_t *bufpoi, *oob, *buf; + int use_bufpoi; unsigned int max_bitflips = 0; int retry_mode = 0; bool ecc_fail = false; @@ -1523,9 +1524,20 @@ static int nand_do_read_ops(struct mtd_info *mtd, loff_t from, bytes = min(mtd->writesize - col, readlen); aligned = (bytes == mtd->writesize); + if (!aligned) + use_bufpoi = 1; + else if (chip->options & NAND_USE_BOUNCE_BUFFER) + use_bufpoi = !virt_addr_valid(buf); + else + use_bufpoi = 0; + /* Is the current page in the buffer? */ if (realpage != chip->pagebuf || oob) { - bufpoi = aligned ? buf : chip->buffers->databuf; + bufpoi = use_bufpoi ? chip->buffers->databuf : buf; + + if (use_bufpoi && aligned) + pr_debug("%s: using read bounce buffer for buf@%p\n", + __func__, buf); read_retry: chip->cmdfunc(mtd, NAND_CMD_READ0, 0x00, page); @@ -1547,7 +1559,7 @@ read_retry: ret = chip->ecc.read_page(mtd, chip, bufpoi, oob_required, page); if (ret < 0) { - if (!aligned) + if (use_bufpoi) /* Invalidate page cache */ chip->pagebuf = -1; break; @@ -1556,7 +1568,7 @@ read_retry: max_bitflips = max_t(unsigned int, max_bitflips, ret); /* Transfer not aligned data */ - if (!aligned) { + if (use_bufpoi) { if (!NAND_HAS_SUBPAGE_READ(chip) && !oob && !(mtd->ecc_stats.failed - ecc_failures) && (ops->mode != MTD_OPS_RAW)) { @@ -2376,11 +2388,23 @@ static int nand_do_write_ops(struct mtd_info *mtd, loff_t to, int bytes = mtd->writesize; int cached = writelen > bytes && page != blockmask; uint8_t *wbuf = buf; + int use_bufpoi; + int part_pagewr = (column || writelen < (mtd->writesize - 1)); + + if (part_pagewr) + use_bufpoi = 1; + else if (chip->options & NAND_USE_BOUNCE_BUFFER) + use_bufpoi = !virt_addr_valid(buf); + else + use_bufpoi = 0; - /* Partial page write? */ - if (unlikely(column || writelen < (mtd->writesize - 1))) { + /* Partial page write?, or need to use bounce buffer */ + if (use_bufpoi) { + pr_debug("%s: using write bounce buffer for buf@%p\n", + __func__, buf); cached = 0; - bytes = min_t(int, bytes - column, (int) writelen); + if (part_pagewr) + bytes = min_t(int, bytes - column, writelen); chip->pagebuf = -1; memset(chip->buffers->databuf, 0xff, mtd->writesize); memcpy(&chip->buffers->databuf[column], buf, bytes); @@ -2618,18 +2642,20 @@ out: } /** - * single_erase_cmd - [GENERIC] NAND standard block erase command function + * single_erase - [GENERIC] NAND standard block erase command function * @mtd: MTD device structure * @page: the page address of the block which will be erased * - * Standard erase command for NAND chips. + * Standard erase command for NAND chips. Returns NAND status. */ -static void single_erase_cmd(struct mtd_info *mtd, int page) +static int single_erase(struct mtd_info *mtd, int page) { struct nand_chip *chip = mtd->priv; /* Send commands to erase a block */ chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page); chip->cmdfunc(mtd, NAND_CMD_ERASE2, -1, -1); + + return chip->waitfunc(mtd, chip); } /** @@ -2710,9 +2736,7 @@ int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr, (page + pages_per_block)) chip->pagebuf = -1; - chip->erase_cmd(mtd, page & chip->pagemask); - - status = chip->waitfunc(mtd, chip); + status = chip->erase(mtd, page & chip->pagemask); /* * See if operation failed and additional status checks are @@ -3607,7 +3631,7 @@ static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd, chip->onfi_version = 0; if (!type->name || !type->pagesize) { - /* Check is chip is ONFI compliant */ + /* Check if the chip is ONFI compliant */ if (nand_flash_detect_onfi(mtd, chip, &busw)) goto ident_done; @@ -3685,7 +3709,7 @@ ident_done: } chip->badblockbits = 8; - chip->erase_cmd = single_erase_cmd; + chip->erase = single_erase; /* Do not replace user supplied command function! */ if (mtd->writesize > 512 && chip->cmdfunc == nand_command) @@ -3770,6 +3794,39 @@ int nand_scan_ident(struct mtd_info *mtd, int maxchips, } EXPORT_SYMBOL(nand_scan_ident); +/* + * Check if the chip configuration meet the datasheet requirements. + + * If our configuration corrects A bits per B bytes and the minimum + * required correction level is X bits per Y bytes, then we must ensure + * both of the following are true: + * + * (1) A / B >= X / Y + * (2) A >= X + * + * Requirement (1) ensures we can correct for the required bitflip density. + * Requirement (2) ensures we can correct even when all bitflips are clumped + * in the same sector. + */ +static bool nand_ecc_strength_good(struct mtd_info *mtd) +{ + struct nand_chip *chip = mtd->priv; + struct nand_ecc_ctrl *ecc = &chip->ecc; + int corr, ds_corr; + + if (ecc->size == 0 || chip->ecc_step_ds == 0) + /* Not enough information */ + return true; + + /* + * We get the number of corrected bits per page to compare + * the correction density. + */ + corr = (mtd->writesize * ecc->strength) / ecc->size; + ds_corr = (mtd->writesize * chip->ecc_strength_ds) / chip->ecc_step_ds; + + return corr >= ds_corr && ecc->strength >= chip->ecc_strength_ds; +} /** * nand_scan_tail - [NAND Interface] Scan for the NAND device @@ -3990,6 +4047,9 @@ int nand_scan_tail(struct mtd_info *mtd) ecc->layout->oobavail += ecc->layout->oobfree[i].length; mtd->oobavail = ecc->layout->oobavail; + /* ECC sanity check: warn noisily if it's too weak */ + WARN_ON(!nand_ecc_strength_good(mtd)); + /* * Set the number of read / write steps for one page depending on ECC * mode. @@ -4023,8 +4083,16 @@ int nand_scan_tail(struct mtd_info *mtd) chip->pagebuf = -1; /* Large page NAND with SOFT_ECC should support subpage reads */ - if ((ecc->mode == NAND_ECC_SOFT) && (chip->page_shift > 9)) - chip->options |= NAND_SUBPAGE_READ; + switch (ecc->mode) { + case NAND_ECC_SOFT: + case NAND_ECC_SOFT_BCH: + if (chip->page_shift > 9) + chip->options |= NAND_SUBPAGE_READ; + break; + + default: + break; + } /* Fill in remaining MTD driver data */ mtd->type = nand_is_slc(chip) ? MTD_NANDFLASH : MTD_MLCNANDFLASH; |