This is a note to let you know that I've just added the patch titled
mtd: rawnand: Prevent crossing LUN boundaries during sequential reads
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mtd-rawnand-prevent-crossing-lun-boundaries-during-sequential-reads.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From bbcd80f53a5e8c27c2511f539fec8c373f500cf4 Mon Sep 17 00:00:00 2001
From: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
Date: Fri, 15 Dec 2023 13:32:05 +0100
Subject: mtd: rawnand: Prevent crossing LUN boundaries during sequential reads
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
From: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
commit bbcd80f53a5e8c27c2511f539fec8c373f500cf4 upstream.
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@xxxxxxxxxxxxxxx
Fixes: 003fe4b9545b ("mtd: rawnand: Support for sequential cache reads")
Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
Tested-by: Martin Hundebøll <martin@xxxxxxxxxx>
Link: https://lore.kernel.org/linux-mtd/20231215123208.516590-2-miquel.raynal@xxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/mtd/nand/raw/nand_base.c | 43 +++++++++++++++++++++++++++++++++------
include/linux/mtd/rawnand.h | 2 +
2 files changed, 39 insertions(+), 6 deletions(-)
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -1208,6 +1208,23 @@ static int nand_lp_exec_read_page_op(str
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)
@@ -1226,7 +1243,7 @@ static int nand_lp_exec_cont_read_page_o
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),
@@ -1263,16 +1280,29 @@ static int nand_lp_exec_cont_read_page_o
}
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;
}
/**
@@ -3446,6 +3476,7 @@ static void rawnand_enable_cont_reads(st
if (col)
chip->cont_read.first_page++;
chip->cont_read.last_page = page + ((readlen >> chip->page_shift) & chip->pagemask);
+ rawnand_cap_cont_reads(chip);
}
/**
--- a/include/linux/mtd/rawnand.h
+++ b/include/linux/mtd/rawnand.h
@@ -1265,6 +1265,7 @@ struct nand_secure_region {
* @cont_read: Sequential page read internals
* @cont_read.ongoing: Whether a continuous read is ongoing or not
* @cont_read.first_page: Start of the continuous read operation
+ * @cont_read.pause_page: End of the current sequential cache read operation
* @cont_read.last_page: End of the continuous read operation
* @controller: The hardware controller structure which is shared among multiple
* independent devices
@@ -1321,6 +1322,7 @@ struct nand_chip {
struct {
bool ongoing;
unsigned int first_page;
+ unsigned int pause_page;
unsigned int last_page;
} cont_read;
Patches currently in stable-queue which might be from miquel.raynal@xxxxxxxxxxx are
queue-6.6/mtd-rawnand-prevent-crossing-lun-boundaries-during-sequential-reads.patch
queue-6.6/mtd-rawnand-fix-core-interference-with-sequential-reads.patch
queue-6.6/mtd-rawnand-clarify-conditions-to-enable-continuous-reads.patch
queue-6.6/mtd-rawnand-prevent-sequential-reads-with-on-die-ecc-engines.patch
queue-6.6/mtd-maps-vmu-flash-fix-the-mtd-core-switch-to-ref-counters.patch
