linux-kernel - [PATCH v2 27/27] mtd: spi-nor: winbond: Add W25Q02NWxxIM CMP locking support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20260108-winbond-v6-18-rc1-spi-nor-swp-v2-27-c462ef806130@bootlin.com>
Date: Thu, 08 Jan 2026 17:58:00 +0100
From: Miquel Raynal <miquel.raynal@...tlin.com>
To: Tudor Ambarus <tudor.ambarus@...aro.org>, 
 Pratyush Yadav <pratyush@...nel.org>, Michael Walle <mwalle@...nel.org>, 
 Richard Weinberger <richard@....at>, Vignesh Raghavendra <vigneshr@...com>, 
 Jonathan Corbet <corbet@....net>
Cc: Sean Anderson <sean.anderson@...ux.dev>, 
 Thomas Petazzoni <thomas.petazzoni@...tlin.com>, 
 Steam Lin <STLin2@...bond.com>, linux-mtd@...ts.infradead.org, 
 linux-kernel@...r.kernel.org, linux-doc@...r.kernel.org, 
 Miquel Raynal <miquel.raynal@...tlin.com>
Subject: [PATCH v2 27/27] mtd: spi-nor: winbond: Add W25Q02NWxxIM CMP
 locking support

This chip has support for the locking complement (CMP) feature. Add
the relevant bit to enable it.

Unfortunately, this chip also comes with an incorrect BFPT table,
indicating the Control Register cannot be read back. This is wrong,
reading back the register works and has no (observed) side effect. The
datasheet clearly indicates supporting the 35h command and all bits from
the CR are marked readable. QE and CMP bits are inside, and can be
properly read back.

Add a fixup for this, otherwise it would defeat the use of the CMP
feature.

Signed-off-by: Miquel Raynal <miquel.raynal@...tlin.com>
---
Test run with W25Q02NWxxIM:
$ flash_lock -u /dev/mtd0
$ flash_lock -l /dev/mtd0 $bs $all_but_one # all but the first
$ show_sectors
locked sectors
 region (in hex)   | status   | #blocks
 ------------------+----------+--------
 00000000-0000ffff | unlocked | 1
 00010000-0fffffff |   locked | 4095
$ flash_lock -u /dev/mtd0 $bs 1 # all but the two first
$ show_sectors
locked sectors
 region (in hex)   | status   | #blocks
 ------------------+----------+--------
 00000000-0001ffff | unlocked | 2
 00020000-0fffffff |   locked | 4094
$ flash_lock -u /dev/mtd0
$ flash_lock -l /dev/mtd0 0 $all_but_one # same from the other side
$ show_sectors
locked sectors
 region (in hex)   | status   | #blocks
 ------------------+----------+--------
 00000000-0ffeffff |   locked | 4095
 0fff0000-0fffffff | unlocked | 1
$ flash_lock -u /dev/mtd0 $(($size - (2 * $bs))) 1 # all but two
$ show_sectors
locked sectors
 region (in hex)   | status   | #blocks
 ------------------+----------+--------
 00000000-0ffdffff |   locked | 4094
 0ffe0000-0fffffff | unlocked | 2
---
 drivers/mtd/spi-nor/winbond.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/spi-nor/winbond.c b/drivers/mtd/spi-nor/winbond.c
index 72053a4505f9..639d72f48769 100644
--- a/drivers/mtd/spi-nor/winbond.c
+++ b/drivers/mtd/spi-nor/winbond.c
@@ -377,7 +377,9 @@ static const struct flash_info winbond_nor_parts[] = {
 	}, {
 		/* W25Q02NWxxIM */
 		.id = SNOR_ID(0xef, 0x80, 0x22),
-		.flags = SPI_NOR_HAS_LOCK | SPI_NOR_HAS_TB | SPI_NOR_TB_SR_BIT6 | SPI_NOR_4BIT_BP,
+		.flags = SPI_NOR_HAS_LOCK | SPI_NOR_HAS_TB | SPI_NOR_TB_SR_BIT6 |
+			 SPI_NOR_4BIT_BP | SPI_NOR_HAS_CMP,
+		.fixups = &winbond_rdcr_fixup,
 	}, {
 		/* W25H512NWxxAM */
 		.id = SNOR_ID(0xef, 0xa0, 0x20),

-- 
2.51.1