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authorMiquel Raynal <miquel.raynal@bootlin.com>2023-12-15 13:32:05 +0100
committerMiquel Raynal <miquel.raynal@bootlin.com>2023-12-22 12:38:46 +0100
commitbbcd80f53a5e8c27c2511f539fec8c373f500cf4 (patch)
treefa2a8a82d0eb77a13c54e37c2845301f0e04d9cc /drivers/mtd
parenta43bdc376deab5fff1ceb93dca55bcab8dbdc1d6 (diff)
downloadlwn-bbcd80f53a5e8c27c2511f539fec8c373f500cf4.tar.gz
lwn-bbcd80f53a5e8c27c2511f539fec8c373f500cf4.zip
mtd: rawnand: Prevent crossing LUN boundaries during sequential reads
The ONFI specification states that devices do not need to support sequential reads across LUN boundaries. In order to prevent such event from happening and possibly failing, let's introduce the concept of "pause" in the sequential read to handle these cases. The first/last pages remain the same but any time we cross a LUN boundary we will end and restart (if relevant) the sequential read operation. Cc: stable@vger.kernel.org Fixes: 003fe4b9545b ("mtd: rawnand: Support for sequential cache reads") Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Tested-by: Martin Hundebøll <martin@geanix.com> Link: https://lore.kernel.org/linux-mtd/20231215123208.516590-2-miquel.raynal@bootlin.com
Diffstat (limited to 'drivers/mtd')
-rw-r--r--drivers/mtd/nand/raw/nand_base.c43
1 files changed, 37 insertions, 6 deletions
diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
index 9e24bedffd89..04e80ace4182 100644
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -1207,6 +1207,23 @@ static int nand_lp_exec_read_page_op(struct nand_chip *chip, unsigned int page,
return nand_exec_op(chip, &op);
}
+static void rawnand_cap_cont_reads(struct nand_chip *chip)
+{
+ struct nand_memory_organization *memorg;
+ unsigned int pages_per_lun, 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;
+
+ /* 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;
+ else
+ chip->cont_read.pause_page = chip->cont_read.last_page;
+}
+
static int nand_lp_exec_cont_read_page_op(struct nand_chip *chip, unsigned int page,
unsigned int offset_in_page, void *buf,
unsigned int len, bool check_only)
@@ -1225,7 +1242,7 @@ static int nand_lp_exec_cont_read_page_op(struct nand_chip *chip, unsigned int p
NAND_OP_DATA_IN(len, buf, 0),
};
struct nand_op_instr cont_instrs[] = {
- NAND_OP_CMD(page == chip->cont_read.last_page ?
+ NAND_OP_CMD(page == chip->cont_read.pause_page ?
NAND_CMD_READCACHEEND : NAND_CMD_READCACHESEQ,
NAND_COMMON_TIMING_NS(conf, tWB_max)),
NAND_OP_WAIT_RDY(NAND_COMMON_TIMING_MS(conf, tR_max),
@@ -1262,16 +1279,29 @@ static int nand_lp_exec_cont_read_page_op(struct nand_chip *chip, unsigned int p
}
if (page == chip->cont_read.first_page)
- return nand_exec_op(chip, &start_op);
+ ret = nand_exec_op(chip, &start_op);
else
- return nand_exec_op(chip, &cont_op);
+ ret = nand_exec_op(chip, &cont_op);
+ if (ret)
+ return ret;
+
+ 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) {
+ chip->cont_read.ongoing = false;
+ }
+
+ return 0;
}
static bool rawnand_cont_read_ongoing(struct nand_chip *chip, unsigned int page)
{
- return chip->cont_read.ongoing &&
- page >= chip->cont_read.first_page &&
- page <= chip->cont_read.last_page;
+ return chip->cont_read.ongoing && page >= chip->cont_read.first_page;
}
/**
@@ -3445,6 +3475,7 @@ static void rawnand_enable_cont_reads(struct nand_chip *chip, unsigned int page,
if (col)
chip->cont_read.first_page++;
chip->cont_read.last_page = page + ((readlen >> chip->page_shift) & chip->pagemask);
+ rawnand_cap_cont_reads(chip);
}
/**