From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f45.google.com (mail-wr1-f45.google.com [209.85.221.45]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9A62636F905 for ; Sat, 10 Oct 2026 18:08:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.45 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791655732; cv=none; b=oHJ+3nqBjjwyHqJ5UtKXHTRV759j4TTDhPfmZHpOM/AjWuwIOVhiWEpb3jn1CsI23ap9m/6bNmFAcoaneSxEhDNFzl0/eoEjaPvYP0L7MeUMRnN0s6OpmAySrue2KkDb1ICWssQg9wrhHEymdcH06wDdDBLTMkyp3I4kpQpdeeA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791655732; c=relaxed/simple; bh=DJKN0VmNDT69jFZYblbYuGHYIcyX6GAnV11ADANjPFc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rviKNMNa6j6fAS8s/gdzGuOpN+LnOfaXR91Sf5h37yXV5Pb4qT7wCVetASK1Udf0bA9Whoxf+IayAINpiLkQicl+zpGEf6OdTN7YDH49fQQzNslWIfxwUPATicXUpYkH1tE6gh67ErY2Tq3GO5vB+RRVV1+3IJZjVDbe60wM37c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=LFFFyCTO; arc=none smtp.client-ip=209.85.221.45 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="LFFFyCTO" Received: by mail-wr1-f45.google.com with SMTP id ffacd0b85a97d-48afe75f055so650062f8f.2 for ; Sat, 10 Oct 2026 11:08:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1791655729; x=1792260529; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=Uu6tLw7RBdSZwF7/zjsiaXn5M72rA/y7SVsm74T1Ulw=; b=LFFFyCTO8ELJLvcDp2Y3KIPgC4qx+56Cx4GwU8ZLZ0rvTKT+UV7Q7/Npbk4+8SPBra 7gqGx14zPKbPflcCNgDdr+y00g6sGzsSe274OWij51fXz1dDshs1kUjZ8Omz/I/N7T7+ AZOIeUTfykjU1OeiYOVzBOhGDN8/b7Q76oq3LrM8C1AFQ572YrghqXgkiC6p0sDwdJZQ hxfp4XTMPtdfxAUrJMYaNs+T+wfLatnVO4/w+oWWCFQ+tcucJmqEcv6r9h1rngs49Sog N8kTMWvIbZPv8GDF3O6ejCyfabT1XN4g4E7cnYhP7W1VInn905Sy43u9pV9gF7xqDmbF UH0g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1791655729; x=1792260529; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=Uu6tLw7RBdSZwF7/zjsiaXn5M72rA/y7SVsm74T1Ulw=; b=wel6RinpWlARchXo9y3lOxSeTWWAjUH6JzCmkLKm7VsULixGYpzj0+HZT7VtTBIS/D Il5Sp52jmzpR8quIMfXuf5B1H2oYUhoO1FARXtu+hbT3X9P2gYQhdS8+ImR3Fqok/JwY CIBRtwg+NPCsxms8P3/MJ+PNDBJ65xzRdCieR3jitsu8o6oGN9yH1QGKz7jXaCmbDshM reEP5CW2C1RSZnn9qV9lh5WCcG+lGq7W77k/Ov599i4TviSXvE6BqQX4snFznInHT15N 71fZrmMi7UvjrKRpdmvPrZyGWtLhBUo9ol7bERQ0rJk4eSBI9JhXHQiN29Ie695P3YDm 01zA== X-Forwarded-Encrypted: i=1; AKwUvBwZQOyA3JSyYrs75/BN8EwF8XDikOoPP4Js17bL3MdORQAlfTd1IiM073Wwc1Jgkvz6bnGIzM9R3cvZVdM=@vger.kernel.org X-Gm-Message-State: AFq9FYIN6c9/iSke7WnWJ4gDq7ri2irnLflrIlCASyMOExo1MlAbTchR 8yUjytZSG1qb6bNpl/0cDcOhSas6sRrxKxvGCzdJscE+YNaWid3qtW7w X-Gm-Gg: AYBFou3KgYlVxxErqI5rO0HPIGeiSEOnJg3dTlRUmEcB+oOpG4p+Kk0DXjSUbhA1C9q CIhSDLuy3zHM9CHAFkM9Zhhio4hs7XnsE72ASD6/riVOD1woVmFhrutKiQnaLIxpWph/k6fX9T9 GOeKQrzpLGxVgYuIzullf4QDHACg/BJsjiWXLNHAMCeSzhEsBXkTHH0zKUn1DsFsSI1XYmwrJlQ dhslAhnCm1/rGmS+zxngzV7g9ic5iAy0xxLV4b2Gq+PG0Ojx42Vxxil7dtvBd/uBD++lcVvHL3G aQop1HRuvX/z7aWsp54AHPtzIhHcg9ZzMF2nZEdDKFQX/m/k4Xx+3pn4iRkMLPMuqz4z2XEsi3n ZbYATNq383DmOAIfaNKAUfFsNZNxnTQxWYIduP2dqWZ7iyrS7Aa1Nz+dq8K+rUmbj3Eix860K4d k/K8NrizQtKoWMDCRTMCWVGn+G4IFlL8AM0IVla0DCF/PXX9JUbEobJCq2902VY5HQuv9tDVgyQ DdTkLQHUjl0NvpocT1SDDUuaVrfuNg8YkHUco4PJMJgg320Hnd/KdbTerbPlS7sMk44rcOCiqjA cJijHVrTSdafYLFS X-Received: by 2002:a05:6000:2383:b0:48a:f509:c22a with SMTP id ffacd0b85a97d-48dba703c63mr8497882f8f.0.1791655728619; Sat, 10 Oct 2026 11:08:48 -0700 (PDT) Received: from center.jhjvjihww5qejoy14qwv1cc4td.frax.internal.cloudapp.net ([131.189.143.225]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-48db97ce3aasm10187163f8f.21.2026.10.10.11.08.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 10 Oct 2026 11:08:47 -0700 (PDT) From: Orgad Shaneh To: miquel.raynal@bootlin.com, richard@nod.at, vigneshr@ti.com, tsbogend@alpha.franken.de Cc: linux-mtd@lists.infradead.org, linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, linusw@kernel.org, kaloz@openwrt.org, ulli.kroll@googlemail.com, john@phrozen.org, nico@fluxnic.net, dwmw2@infradead.org, corbet@lwn.net, linux-doc@vger.kernel.org Subject: [PATCH v2 2/3] mtd: cfi_cmdset_0002: implement point() for simple linear maps Date: Sat, 10 Oct 2026 18:08:39 +0000 Message-ID: <20261010180840.2152492-3-orgads@gmail.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20261010180840.2152492-1-orgads@gmail.com> References: <20261010172142.2138956-1-orgads@gmail.com> <20261010180840.2152492-1-orgads@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit cfi_cmdset_0001 lets a linearly mapped chip be pointed at, so jffs2 can scan it in place. cfi_cmdset_0002 never got point(), and the jffs2 mount on an AMD-style NOR copies every used eraseblock through map_copy_from() instead. Add a point()/unpoint() pair modeled on cfi_intelext_point(), entering array mode with the AMD reset command; get_chip() already handles FL_POINT. Like cfi_cmdset_0001 it is only enabled for maps that are linear and read through the simple accessors. Where it differs: - Points share the chip when no operation is suspended, and the reboot reset may proceed from an idle FL_POINT (the chip is already in array mode); an unpoint after that reset is not an error. On cfi_cmdset_0001 a point held across reboot leaves cfi_intelext_reset() waiting forever. - unpoint() releases the chip only when the last reference goes, and point() returns the error when nothing could be pointed. - A point never suspends an erase; it waits for the erase to finish. The erase would otherwise stay suspended for as long as the point is held, and the reboot reset with it. As with cfi_cmdset_0001, a held point makes writes, erases and sync on that chip wait uninterruptibly for the last unpoint, and system suspend fails with -EAGAIN. That matters for cramfs on MTD (CONFIG_CRAMFS_MTD), which keeps its whole image pointed while mounted: before this patch mtd_point() failed on AMD chips and cramfs fell back to the block device; now, with cramfs and jffs2 on the same chip, jffs2 writes and garbage collection, flash_erase, sync(2) - and so reboot(8), which syncs first - block until cramfs is unmounted. Name cfi_cmdset_0002 next to cfi_cmdset_0001 in the cramfs documentation's list of drivers that support point(). On an Octeon CN6635 board with a 100 MB jffs2 partition on an M29EW (8-bit bus, ~3.4 MB/s reads) the mount drops from 15-30 s to under 1 s. Assisted-by: Claude:claude-opus-5-5 Signed-off-by: Orgad Shaneh Cc: Nicolas Pitre Cc: David Woodhouse --- v2: a point no longer suspends an erase in progress; it waits for the erase instead (sashiko). Documentation/filesystems/cramfs.rst | 11 +- drivers/mtd/chips/cfi_cmdset_0002.c | 162 ++++++++++++++++++++++++++- 2 files changed, 165 insertions(+), 8 deletions(-) diff --git a/Documentation/filesystems/cramfs.rst b/Documentation/filesystems/cramfs.rst index 221c0bf..7b706c5 100644 --- a/Documentation/filesystems/cramfs.rst +++ b/Documentation/filesystems/cramfs.rst @@ -75,11 +75,12 @@ The location of the cramfs image in memory is system dependent. You must know the proper physical address where the cramfs image is located and configure an MTD device for it. Also, that MTD device must be supported by a map driver that implements the "point" method. Examples of such -MTD drivers are cfi_cmdset_0001 (Intel/Sharp CFI flash) or physmap -(Flash device in physical memory map). MTD partitions based on such devices -are fine too. Then that device should be specified with the "mtd:" prefix -as the mount device argument. For example, to mount the MTD device named -"fs_partition" on the /mnt directory:: +MTD drivers are cfi_cmdset_0001 (Intel/Sharp CFI flash), cfi_cmdset_0002 +(AMD/Fujitsu CFI flash) or physmap (Flash device in physical memory map). +MTD partitions based on such devices are fine too. Then that device should +be specified with the "mtd:" prefix as the mount device argument. For +example, to mount the MTD device named "fs_partition" on the /mnt +directory:: $ mount -t cramfs mtd:fs_partition /mnt diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c index bd4f1ed..7abb101 100644 --- a/drivers/mtd/chips/cfi_cmdset_0002.c +++ b/drivers/mtd/chips/cfi_cmdset_0002.c @@ -63,6 +63,9 @@ enum cfi_quirks { }; static int cfi_amdstd_read (struct mtd_info *, loff_t, size_t, size_t *, u_char *); +static int cfi_amdstd_point(struct mtd_info *mtd, loff_t from, size_t len, + size_t *retlen, void **virt, resource_size_t *phys); +static int cfi_amdstd_unpoint(struct mtd_info *mtd, loff_t from, size_t len); static int cfi_amdstd_write_words(struct mtd_info *, loff_t, size_t, size_t *, const u_char *); #if !FORCE_WORD_WRITE static int cfi_amdstd_write_buffers(struct mtd_info *, loff_t, size_t, size_t *, const u_char *); @@ -512,6 +515,22 @@ static struct cfi_fixup jedec_fixup_table[] = { { 0, 0, NULL } }; +/* + * Let jffs2 scan a linearly mapped flash in place, as cfi_cmdset_0001 + * does: without point() its mount copies every used eraseblock. Only + * for maps read through the simple accessors - a pointer bypasses any + * byte swapping or bus locking a map driver does in its own. + */ +static void fixup_use_point(struct mtd_info *mtd) +{ + struct map_info *map = mtd->priv; + + if (!mtd->_point && map_is_linear(map) && map_is_simple(map)) { + mtd->_point = cfi_amdstd_point; + mtd->_unpoint = cfi_amdstd_unpoint; + } +} + static struct cfi_fixup fixup_table[] = { /* The CFI vendor ids and the JEDEC vendor IDs appear * to be common. It is like the devices id's are as @@ -519,6 +538,7 @@ static struct cfi_fixup fixup_table[] = { * we know that is the case. */ { CFI_MFR_ANY, CFI_ID_ANY, fixup_use_erase_chip }, + { CFI_MFR_ANY, CFI_ID_ANY, fixup_use_point }, { CFI_MFR_ATMEL, AT49BV6416, fixup_use_atmel_lock }, { 0, 0, NULL } }; @@ -922,8 +942,12 @@ static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr return 0; case FL_ERASING: + /* + * Not for a point: the erase would stay suspended for as + * long as it is held, which for cramfs is the whole mount. + */ if (!cfip || !(cfip->EraseSuspend & (0x1|0x2)) || - !(mode == FL_READY || mode == FL_POINT || + !(mode == FL_READY || (mode == FL_WRITING && (cfip->EraseSuspend & 0x2)))) goto sleep; @@ -976,8 +1000,13 @@ static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr return -EIO; case FL_POINT: - /* Only if there's no operation suspended... */ - if (mode == FL_READY && chip->oldstate == FL_READY) + /* + * Only if there's no operation suspended: the chip is in + * array mode, so reads, further points and the reboot + * reset (which only re-enters array mode) can go ahead. + */ + if ((mode == FL_READY || mode == FL_POINT || + mode == FL_SHUTDOWN) && chip->oldstate == FL_READY) return 0; fallthrough; default: @@ -1216,6 +1245,133 @@ do { \ #endif +static int do_point_onechip(struct map_info *map, struct flchip *chip, + loff_t adr, size_t len) +{ + unsigned long cmd_addr; + struct cfi_private *cfi = map->fldrv_priv; + int ret; + + adr += chip->start; + + /* Ensure cmd read/writes are aligned. */ + cmd_addr = adr & ~(map_bankwidth(map) - 1); + + mutex_lock(&chip->mutex); + ret = get_chip(map, chip, cmd_addr, FL_POINT); + if (!ret) { + if (chip->state != FL_POINT && chip->state != FL_READY) + map_write(map, CMD(0xf0), cmd_addr); + + chip->state = FL_POINT; + chip->ref_point_counter++; + } + mutex_unlock(&chip->mutex); + + return ret; +} + +static int cfi_amdstd_point(struct mtd_info *mtd, loff_t from, size_t len, + size_t *retlen, void **virt, resource_size_t *phys) +{ + struct map_info *map = mtd->priv; + struct cfi_private *cfi = map->fldrv_priv; + unsigned long ofs, last_end = 0; + int chipnum; + int ret = -EINVAL; + + if (!map->virt) + return -EINVAL; + + /* ofs: offset within the first chip that the first read should start */ + chipnum = (from >> cfi->chipshift); + ofs = from - (chipnum << cfi->chipshift); + + *virt = map->virt + cfi->chips[chipnum].start + ofs; + if (phys) + *phys = map->phys + cfi->chips[chipnum].start + ofs; + + while (len) { + unsigned long thislen; + + if (chipnum >= cfi->numchips) + break; + + /* We cannot point across chips that are virtually disjoint */ + if (!last_end) + last_end = cfi->chips[chipnum].start; + else if (cfi->chips[chipnum].start != last_end) + break; + + if ((len + ofs - 1) >> cfi->chipshift) + thislen = (1 << cfi->chipshift) - ofs; + else + thislen = len; + + ret = do_point_onechip(map, &cfi->chips[chipnum], ofs, thislen); + if (ret) + break; + + *retlen += thislen; + len -= thislen; + + ofs = 0; + last_end += 1 << cfi->chipshift; + chipnum++; + } + return *retlen ? 0 : ret; +} + +static int cfi_amdstd_unpoint(struct mtd_info *mtd, loff_t from, size_t len) +{ + struct map_info *map = mtd->priv; + struct cfi_private *cfi = map->fldrv_priv; + unsigned long ofs; + int chipnum, err = 0; + + /* ofs: offset within the first chip that the first read should start */ + chipnum = (from >> cfi->chipshift); + ofs = from - (chipnum << cfi->chipshift); + + while (len && !err) { + unsigned long thislen; + struct flchip *chip; + + if (chipnum >= cfi->numchips) + break; + chip = &cfi->chips[chipnum]; + + if ((len + ofs - 1) >> cfi->chipshift) + thislen = (1 << cfi->chipshift) - ofs; + else + thislen = len; + + mutex_lock(&chip->mutex); + if (chip->state == FL_POINT) { + /* The last reader resumes whatever the first suspended */ + if (--chip->ref_point_counter == 0) { + chip->state = FL_READY; + put_chip(map, chip, chip->start); + } + } else if (chip->state != FL_SHUTDOWN) { + /* + * After the reboot reset nothing is pointed any more; + * ref_point_counter no longer matters there. + */ + pr_err("%s: Error: unpoint called on non pointed region\n", + map->name); + err = -EINVAL; + } + mutex_unlock(&chip->mutex); + + len -= thislen; + ofs = 0; + chipnum++; + } + + return err; +} + static inline int do_read_onechip(struct map_info *map, struct flchip *chip, loff_t adr, size_t len, u_char *buf) { unsigned long cmd_addr; -- 2.53.0