From nobody Sun Feb 8 00:26:26 2026 Received: from smtpout-03.galae.net (smtpout-03.galae.net [185.246.85.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 52AC5393DF8 for ; Wed, 4 Feb 2026 08:32:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.246.85.4 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770193948; cv=none; b=DZGQZeXJDLq12lN60SwSca+Ni3fSPttADuLuthsEWLF4tDGUp8+GM+KyzhPjxz67iLwt7JdfD+AECIPY+epgEm2hnneIuO5eo4TLAERb6w6DzIPuSjO3OQ/Zm5ccfEoGWojYGhVGnZuSNEKuwj+ljPGMCIK9p6daeONQMXyub20= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770193948; c=relaxed/simple; bh=dqka4r6BuBn7lQjOaxkDblcgGRl2sfENyycfL8OQI7U=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=YBXcR4d8nLt1MKzNEbthzJjy/kdwdj2ZloIu4UNr9RJo+g8B3dffFvY09vWfij082ykkcjRE0RxHn7xqNoAw7vym8kiGBCTwtJt4FMJ/fRdcjVW1ZnEL8e5xn7t5aTiIH7nP1ZghRE2FUN22iYWVDkguKc8tfwveGyqu7Fplfbw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=AOcKfgkD; arc=none smtp.client-ip=185.246.85.4 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="AOcKfgkD" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-03.galae.net (Postfix) with ESMTPS id E24C34E423F2; Wed, 4 Feb 2026 08:32:26 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id B225C60745; Wed, 4 Feb 2026 08:32:26 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 3BAC2119A8891; Wed, 4 Feb 2026 09:32:23 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1770193945; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=BtPoBGuOTOslAVtD4AMARgD4qfustmM5dmvT1q96w9U=; b=AOcKfgkDTJ7rzc0EkCjo06AJMjsyHTxZXBURUS7X9rQcILK1TekbdS65wy4Fd6zOwmiGHx P17eHChNDxNt+UVSWHh/7apcARsFkNctCqMU+nIexZ7ueL1G4sVd1oOidLCTqgTAA7aCn3 gz+X1IPjGIOIR4zAl8MEtNImwWbEVuQAHLd2MmWbJv8C2YypFyATP694GGxKy2GH47vdPq Bfwy4b93JeBwQlYDDQ9ar84YCjXD7e+GavVwgTmNiYpBLZQCx70SVVN+k+vbzXhtlrL0of QRWsD2YiTIU/G/7AfAq1WOA12ChfLSQOmGvwuuNvHeDWFw2fpjQ3UPJ1I251Ew== From: Luca Ceresoli Date: Wed, 04 Feb 2026 09:32:16 +0100 Subject: [PATCH v17 1/3] dt-bindings: mtd: Describe MTD partitions concatenation Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260204-mtd-virt-concat-v17-1-5e98239bb55b@bootlin.com> References: <20260204-mtd-virt-concat-v17-0-5e98239bb55b@bootlin.com> In-Reply-To: <20260204-mtd-virt-concat-v17-0-5e98239bb55b@bootlin.com> To: Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Rob Herring , Krzysztof Kozlowski , Conor Dooley , =?utf-8?q?Rafa=C5=82_Mi=C5=82ecki?= Cc: Amit Kumar Mahapatra , Michal Simek , Bernhard Frauendienst , Thomas Petazzoni , linux-mtd@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Luca Ceresoli X-Mailer: b4 0.14.3 X-Last-TLS-Session-Version: TLSv1.3 From: Amit Kumar Mahapatra The AMD QSPI controller supports an advanced connection modes called Stacked mode which allow the controller to treat two different flashes as one storage. In Stacked connection mode flashes share the same SPI bus, but different CS line, controller driver asserts the CS of the flash to which it needs to communicate. Stacked mode is a software abstraction rather than a controller feature or capability. At any given time, the controller communicates with one of the two connected flash devices, as determined by the requested address and data length. If an operation starts on one flash and ends on the other, the mtd layer needs to split it into two separate operations and adjust the data length accordingly. For more information on the modes please feel free to go through the controller flash interface below [1]. To support stacked mode, the existing MTD concat driver has been extended to be more generic, enabling multiple sets of MTD partitions to be virtually concatenated, with each set forming a distinct logical MTD device. A new Device Tree property is introduced to facilitate this, containing phandles of the partitions to be concatenated with the one where the property is defined. This approach supports multiple sets of concatenated partitions. [1] https://docs.amd.com/r/en-US/am011-versal-acap-trm/QSPI-Flash-Device-In= terface Suggested-by: Miquel Raynal Suggested-by: Rob Herring Signed-off-by: Amit Kumar Mahapatra Reviewed-by: Rob Herring (Arm) Signed-off-by: Luca Ceresoli --- .../bindings/mtd/partitions/partition.yaml | 20 ++++++++++++++++= ++++ 1 file changed, 20 insertions(+) diff --git a/Documentation/devicetree/bindings/mtd/partitions/partition.yam= l b/Documentation/devicetree/bindings/mtd/partitions/partition.yaml index 80d0452a2a33..c9aba6838b3c 100644 --- a/Documentation/devicetree/bindings/mtd/partitions/partition.yaml +++ b/Documentation/devicetree/bindings/mtd/partitions/partition.yaml @@ -57,6 +57,15 @@ properties: user space from type: boolean =20 + part-concat-next: + description: List of phandles to MTD partitions that need be concatena= ted + with the current partition. + $ref: /schemas/types.yaml#/definitions/phandle-array + minItems: 1 + maxItems: 16 + items: + maxItems: 1 + align: $ref: /schemas/types.yaml#/definitions/uint32 minimum: 2 @@ -138,4 +147,15 @@ examples: reg =3D <0x200000 0x100000>; align =3D <0x4000>; }; + + part0: partition@400000 { + part-concat-next =3D <&part1>; + label =3D "part0_0"; + reg =3D <0x400000 0x100000>; + }; + + part1: partition@800000 { + label =3D "part0_1"; + reg =3D <0x800000 0x800000>; + }; }; --=20 2.52.0 From nobody Sun Feb 8 00:26:26 2026 Received: from smtpout-04.galae.net (smtpout-04.galae.net [185.171.202.116]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B216F39449B for ; Wed, 4 Feb 2026 08:32:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.171.202.116 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770193950; cv=none; b=gSzdniKAU7jDg8J/MlRzRddjDwEy6GVwZpV/ayuM0uq8mJ6l1WqvmwADnUK1fxUyHk0lb1mOoTTor4XUnVuN9oqIP1DYy8KCI+kVvIqeKhuEWkQGAiT/pvjDr0lFrXFntzeQdPV70mKxknrRa561GxfxAy4kryxZnyIVBrtOmG8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770193950; c=relaxed/simple; bh=oZAtESGQZtH5Gc9X3cmSQvtaXUHOXsWSJ0faQoOiao4=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=IZWdRduNewBGhUndz230mzxs+x8Md5D0S7zLIS6gY3JARbIuu7lLPt1FQHM/HYBRcFAggZN0BzIpfp1oJZhyfk7FFRRUBrNxsugQ2kLs8C4R1puMUGaw4BUBxEeYByG3Gbs9TTAOdnrE2DSSd2f2G0H6pkdx7QQbhp41HJPaxvI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=v5ZRduBK; arc=none smtp.client-ip=185.171.202.116 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="v5ZRduBK" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-04.galae.net (Postfix) with ESMTPS id 8E5D5C24396; Wed, 4 Feb 2026 08:32:34 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id F08D560745; Wed, 4 Feb 2026 08:32:28 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 23ADA119A88EE; Wed, 4 Feb 2026 09:32:25 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1770193948; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=IYfYtxqAQMooFvbBZW5NCWAmFPox9AqB9Ege5HL77z0=; b=v5ZRduBKWMMRuSKuRspNwIDtb7UudzHiBBXA3eaFDXAdK4Y2CcfMgctUqny75n40aMSI1M hzfqWzsO5mkhQVHC2hWmFCONPGAHZUjxKYeCytL6I+yiViC/yn096vy8PmHYbhs2kenbDC aFQvcGcJRUmXd67k6sRMol45gQlHx+A7Oirhb02Ie93ydFwcY13aahBd+Yds8WYhFI6Tki szVvh9RMDp5ukN4A+9446DDh80FC8fMW32HxgWJfniD3lxSTjFUuZr0hP3ch8hsbeXujuK 3CNv3Bx9QQ+9SEKopzBdU0h4Fq29HoRd4hDOQR3ZEbqjAyYRnjuBA8fwSDf2zA== From: Luca Ceresoli Date: Wed, 04 Feb 2026 09:32:17 +0100 Subject: [PATCH v17 2/3] mtd: Move struct mtd_concat definition to header file Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260204-mtd-virt-concat-v17-2-5e98239bb55b@bootlin.com> References: <20260204-mtd-virt-concat-v17-0-5e98239bb55b@bootlin.com> In-Reply-To: <20260204-mtd-virt-concat-v17-0-5e98239bb55b@bootlin.com> To: Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Rob Herring , Krzysztof Kozlowski , Conor Dooley , =?utf-8?q?Rafa=C5=82_Mi=C5=82ecki?= Cc: Amit Kumar Mahapatra , Michal Simek , Bernhard Frauendienst , Thomas Petazzoni , linux-mtd@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Luca Ceresoli X-Mailer: b4 0.14.3 X-Last-TLS-Session-Version: TLSv1.3 From: Amit Kumar Mahapatra To enable a more generic approach for concatenating MTD devices, struct mtd_concat should be accessible beyond the mtdconcat driver. Therefore, the definition is being moved to a header file. Signed-off-by: Amit Kumar Mahapatra Signed-off-by: Luca Ceresoli --- drivers/mtd/mtdconcat.c | 12 ------------ include/linux/mtd/concat.h | 12 ++++++++++++ 2 files changed, 12 insertions(+), 12 deletions(-) diff --git a/drivers/mtd/mtdconcat.c b/drivers/mtd/mtdconcat.c index f56f44aa8625..6f2aaceac669 100644 --- a/drivers/mtd/mtdconcat.c +++ b/drivers/mtd/mtdconcat.c @@ -20,18 +20,6 @@ =20 #include =20 -/* - * Our storage structure: - * Subdev points to an array of pointers to struct mtd_info objects - * which is allocated along with this structure - * - */ -struct mtd_concat { - struct mtd_info mtd; - int num_subdev; - struct mtd_info **subdev; -}; - /* * how to calculate the size required for the above structure, * including the pointer array subdev points to: diff --git a/include/linux/mtd/concat.h b/include/linux/mtd/concat.h index d6f653e07426..b42d9af87c4e 100644 --- a/include/linux/mtd/concat.h +++ b/include/linux/mtd/concat.h @@ -9,6 +9,18 @@ #define MTD_CONCAT_H =20 =20 +/* + * Our storage structure: + * Subdev points to an array of pointers to struct mtd_info objects + * which is allocated along with this structure + * + */ +struct mtd_concat { + struct mtd_info mtd; + int num_subdev; + struct mtd_info **subdev; +}; + struct mtd_info *mtd_concat_create( struct mtd_info *subdev[], /* subdevices to concatenate */ int num_devs, /* number of subdevices */ --=20 2.52.0 From nobody Sun Feb 8 00:26:26 2026 Received: from smtpout-04.galae.net (smtpout-04.galae.net [185.171.202.116]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5C87539446C; Wed, 4 Feb 2026 08:32:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.171.202.116 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770193953; cv=none; b=f8OBuNRz3miL4wj6UAPVOTGLiHAWgyTYyVcPkfLXe0Rf23f9QpKvnx5+qSSNoVqFb3QfBoFGTLvbrkkGNgyRcmgBq+K4vNSuC+3D55DfAATJZufzXyk1Cx/yEekt4wTIFUWtjy27qUyISLqWRlUNsv1keyQ8oU7E3Ff6R3ZsTD8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770193953; c=relaxed/simple; bh=pRw8y+IiWZvPFQ/5lKlbi1I3kF5Q/L+ow68lmcAeKQ8=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=jbsIwkgwun+sC7mU/VmCc5CiX8wtCouEMsP150q6YL/I4yaNSn14YcJ34HP1dYqitzLh0OvfBuUMl9o+EIWRjvig5c0rx9bI3hL+HBiNC+DD/GUYuHXoqG5Pisl2IpDy26jz3i3PayRryou9n7eLG109T68zmEcr8woEtA4q9sc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=unzf29jp; arc=none smtp.client-ip=185.171.202.116 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="unzf29jp" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-04.galae.net (Postfix) with ESMTPS id 07E16C24394; Wed, 4 Feb 2026 08:32:37 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 6D5FF60745; Wed, 4 Feb 2026 08:32:31 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id B0959119A88F7; Wed, 4 Feb 2026 09:32:28 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1770193950; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=uGNo9gN91d11misuI4sRqCkOuFl1GGBdD/UkwokvZ2E=; b=unzf29jp5LZX6rsrUWENdqu9bep6acrRXLXKNgO/JAcrtJqDRZGsDgquFhlmFi/ua1Cbhp 1t+XIIDkk3nuiC/gbB6vwranklNwkJLXqow3XBnPYhQ4ddBgEP0oEKZC9K4TcunWnOOyqB 19pdfZDhb3bPNh6nz6rHP+s07cmjpFPQod19V//iFEjDCLwQYBYY0nidaOctaZQAwdDwdE TqmoOkFK1n1+3DKMeU1lhI9GYSFd4Sca8iaEJeFYtAV2jogQDDyFbPTEJSb2qD1BDN0Jdc Yd6GDn0T54XnZAOek+IEFN50L2OpZJxAW8dowgj98sNpIqSX9kgxZCyqYnJn7w== From: Luca Ceresoli Date: Wed, 04 Feb 2026 09:32:18 +0100 Subject: [PATCH v17 3/3] mtd: Add driver for concatenating devices Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260204-mtd-virt-concat-v17-3-5e98239bb55b@bootlin.com> References: <20260204-mtd-virt-concat-v17-0-5e98239bb55b@bootlin.com> In-Reply-To: <20260204-mtd-virt-concat-v17-0-5e98239bb55b@bootlin.com> To: Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Rob Herring , Krzysztof Kozlowski , Conor Dooley , =?utf-8?q?Rafa=C5=82_Mi=C5=82ecki?= Cc: Amit Kumar Mahapatra , Michal Simek , Bernhard Frauendienst , Thomas Petazzoni , linux-mtd@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Luca Ceresoli X-Mailer: b4 0.14.3 X-Last-TLS-Session-Version: TLSv1.3 From: Amit Kumar Mahapatra Introducing CONFIG_MTD_VIRT_CONCAT to separate the legacy flow from the new approach, where only the concatenated partition is registered as an MTD device, while the individual partitions that form it are not registered independently, as they are typically not required by the user. CONFIG_MTD_VIRT_CONCAT is a boolean configuration option that depends on CONFIG_MTD_PARTITIONED_MASTER. When enabled, it allows flash nodes to be exposed as individual MTD devices along with the other partitions. The solution focuses on fixed-partitions description only as it depends on device boundaries. It supports multiple sets of concatenated devices, each comprising two or more partitions. flash@0 { reg =3D <0>; partitions { compatible =3D "fixed-partitions"; part0@0 { part-concat-next =3D <&flash0_part1>; label =3D "part0_0"; reg =3D <0x0 0x800000>; }; flash0_part1: part1@800000 { label =3D "part0_1"; reg =3D <800000 0x800000>; }; part2@1000000 { part-concat-next =3D <&flash1_part0>; label =3D "part0_2"; reg =3D <0x800000 0x800000>; }; }; }; flash@1 { reg =3D <1>; partitions { compatible =3D "fixed-partitions"; flash1_part0: part1@0 { label =3D "part1_0"; reg =3D <0x0 0x800000>; }; part1@800000 { label =3D "part1_1"; reg =3D <0x800000 0x800000>; }; }; }; The partitions that gets created are flash@0 part0_0-part0_1-concat flash@1 part1_1 part0_2-part1_0-concat Suggested-by: Bernhard Frauendienst Suggested-by: Miquel Raynal Signed-off-by: Amit Kumar Mahapatra Signed-off-by: Luca Ceresoli --- Changes in v16: - Add missing if (IS_REACHABLE(CONFIG_MTD_VIRT_CONCAT)) to fix build when CONFIG_MTD_VIRT_CONCAT is not enabled Changes in v15: - Build mdt-concat as part of the mtd module, not a separate module because they are interdependent; make the Konfig a bool instead of a tristate so it is a opt-in feature - Remove 'default n' Kconfig line, 'n' is the default anyway --- drivers/mtd/Kconfig | 9 ++ drivers/mtd/Makefile | 1 + drivers/mtd/mtd_virt_concat.c | 363 ++++++++++++++++++++++++++++++++++++++= ++++ drivers/mtd/mtdcore.c | 21 +++ drivers/mtd/mtdpart.c | 6 + include/linux/mtd/concat.h | 51 +++++- 6 files changed, 450 insertions(+), 1 deletion(-) diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig index 796a2eccbef0..0421c6208de7 100644 --- a/drivers/mtd/Kconfig +++ b/drivers/mtd/Kconfig @@ -206,6 +206,15 @@ config MTD_PARTITIONED_MASTER the parent of the partition device be the master device, rather than what lies behind the master. =20 +config MTD_VIRT_CONCAT + bool "Virtual concatenated MTD devices" + depends on MTD_PARTITIONED_MASTER + help + The driver enables the creation of virtual MTD device by + concatenating multiple physical MTD devices into a single + entity. This allows for the creation of partitions larger than + the individual physical chips, extending across chip boundaries. + source "drivers/mtd/chips/Kconfig" =20 source "drivers/mtd/maps/Kconfig" diff --git a/drivers/mtd/Makefile b/drivers/mtd/Makefile index 593d0593a038..7b6dd53e8150 100644 --- a/drivers/mtd/Makefile +++ b/drivers/mtd/Makefile @@ -6,6 +6,7 @@ # Core functionality. obj-$(CONFIG_MTD) +=3D mtd.o mtd-y :=3D mtdcore.o mtdsuper.o mtdconcat.o mtdpart.o mtdchar.o +mtd-$(CONFIG_MTD_VIRT_CONCAT) +=3D mtd_virt_concat.o =20 obj-y +=3D parsers/ =20 diff --git a/drivers/mtd/mtd_virt_concat.c b/drivers/mtd/mtd_virt_concat.c new file mode 100644 index 000000000000..aea88d1c9bc5 --- /dev/null +++ b/drivers/mtd/mtd_virt_concat.c @@ -0,0 +1,363 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Virtual concat MTD device driver + * + * Copyright (C) 2018 Bernhard Frauendienst + * Author: Bernhard Frauendienst + */ + +#include +#include +#include "mtdcore.h" +#include +#include +#include +#include +#include + +#define CONCAT_PROP "part-concat-next" +#define CONCAT_POSTFIX "concat" +#define MIN_DEV_PER_CONCAT 1 + +static LIST_HEAD(concat_node_list); + +/** + * struct mtd_virt_concat_node - components of a concatenation + * @head: List handle + * @count: Number of nodes + * @nodes: Pointer to the nodes (partitions) to concatenate + * @concat: Concatenation container + */ +struct mtd_virt_concat_node { + struct list_head head; + unsigned int count; + struct device_node **nodes; + struct mtd_concat *concat; +}; + +/** + * mtd_is_part_concat - Check if the device is already part + * of a concatenated device + * @dev: pointer to 'device_node' + * + * Return: true if the device is already part of a concatenation, + * false otherwise. + */ +static bool mtd_is_part_concat(struct device_node *dev) +{ + struct mtd_virt_concat_node *item; + int idx; + + list_for_each_entry(item, &concat_node_list, head) { + for (idx =3D 0; idx < item->count; idx++) { + if (item->nodes[idx] =3D=3D dev) + return true; + } + } + return false; +} + +static void mtd_virt_concat_put_mtd_devices(struct mtd_concat *concat) +{ + int i; + + for (i =3D 0; i < concat->num_subdev; i++) + put_mtd_device(concat->subdev[i]); +} + +void mtd_virt_concat_destroy_joins(void) +{ + struct mtd_virt_concat_node *item, *tmp; + struct mtd_info *mtd; + + list_for_each_entry_safe(item, tmp, &concat_node_list, head) { + mtd =3D &item->concat->mtd; + if (item->concat) { + mtd_device_unregister(mtd); + kfree(mtd->name); + mtd_concat_destroy(mtd); + mtd_virt_concat_put_mtd_devices(item->concat); + } + } +} + +/** + * mtd_virt_concat_destroy - Destroy the concat that includes the mtd obje= ct + * @mtd: pointer to 'mtd_info' + * + * Return: 0 on success, -error otherwise. + */ +int mtd_virt_concat_destroy(struct mtd_info *mtd) +{ + struct mtd_info *child, *master =3D mtd_get_master(mtd); + struct mtd_virt_concat_node *item, *tmp; + struct mtd_concat *concat; + int idx, ret =3D 0; + bool is_mtd_found; + + list_for_each_entry_safe(item, tmp, &concat_node_list, head) { + is_mtd_found =3D false; + + /* Find the concat item that hold the mtd device */ + for (idx =3D 0; idx < item->count; idx++) { + if (item->nodes[idx] =3D=3D mtd->dev.of_node) { + is_mtd_found =3D true; + break; + } + } + if (!is_mtd_found) + continue; + concat =3D item->concat; + + /* + * Since this concatenated device is being removed, retrieve + * all MTD devices that are part of it and register them + * individually. + */ + for (idx =3D 0; idx < concat->num_subdev; idx++) { + child =3D concat->subdev[idx]; + if (child->dev.of_node !=3D mtd->dev.of_node) { + ret =3D add_mtd_device(child); + if (ret) + goto out; + } + } + /* Destroy the concat */ + if (concat->mtd.name) { + del_mtd_device(&concat->mtd); + kfree(concat->mtd.name); + mtd_concat_destroy(&concat->mtd); + mtd_virt_concat_put_mtd_devices(item->concat); + } + + for (idx =3D 0; idx < item->count; idx++) + of_node_put(item->nodes[idx]); + + kfree(item->nodes); + kfree(item); + } + return 0; +out: + mutex_lock(&master->master.partitions_lock); + list_del(&child->part.node); + mutex_unlock(&master->master.partitions_lock); + kfree(mtd->name); + kfree(mtd); + + return ret; +} + +/** + * mtd_virt_concat_create_item - Create a concat item + * @parts: pointer to 'device_node' + * @count: number of mtd devices that make up + * the concatenated device. + * + * Return: 0 on success, -error otherwise. + */ +static int mtd_virt_concat_create_item(struct device_node *parts, + unsigned int count) +{ + struct mtd_virt_concat_node *item; + struct mtd_concat *concat; + int i; + + for (i =3D 0; i < (count - 1); i++) { + if (mtd_is_part_concat(of_parse_phandle(parts, CONCAT_PROP, i))) + return 0; + } + + item =3D kzalloc(sizeof(*item), GFP_KERNEL); + if (!item) + return -ENOMEM; + + item->count =3D count; + item->nodes =3D kcalloc(count, sizeof(*item->nodes), GFP_KERNEL); + if (!item->nodes) { + kfree(item); + return -ENOMEM; + } + + /* + * The partition in which "part-concat-next" property + * is defined is the first device in the list of concat + * devices. + */ + item->nodes[0] =3D parts; + + for (i =3D 1; i < count; i++) + item->nodes[i] =3D of_parse_phandle(parts, CONCAT_PROP, (i - 1)); + + concat =3D kzalloc(sizeof(*concat), GFP_KERNEL); + if (!concat) { + kfree(item); + return -ENOMEM; + } + + concat->subdev =3D kcalloc(count, sizeof(*concat->subdev), GFP_KERNEL); + if (!concat->subdev) { + kfree(item); + kfree(concat); + return -ENOMEM; + } + item->concat =3D concat; + + list_add_tail(&item->head, &concat_node_list); + + return 0; +} + +void mtd_virt_concat_destroy_items(void) +{ + struct mtd_virt_concat_node *item, *temp; + int i; + + list_for_each_entry_safe(item, temp, &concat_node_list, head) { + for (i =3D 0; i < item->count; i++) + of_node_put(item->nodes[i]); + + kfree(item->nodes); + kfree(item); + } +} + +/** + * mtd_virt_concat_create_add - Add a mtd device to the concat list + * @mtd: pointer to 'mtd_info' + * + * Return: true on success, false otherwise. + */ +bool mtd_virt_concat_add(struct mtd_info *mtd) +{ + struct mtd_virt_concat_node *item; + struct mtd_concat *concat; + int idx; + + list_for_each_entry(item, &concat_node_list, head) { + concat =3D item->concat; + for (idx =3D 0; idx < item->count; idx++) { + if (item->nodes[idx] =3D=3D mtd->dev.of_node) { + concat->subdev[concat->num_subdev++] =3D mtd; + return true; + } + } + } + return false; +} + +/** + * mtd_virt_concat_node_create - List all the concatenations found in DT + * + * Return: 0 on success, -error otherwise. + */ +int mtd_virt_concat_node_create(void) +{ + struct device_node *parts =3D NULL; + int ret =3D 0, count =3D 0; + + /* List all the concatenations found in DT */ + do { + parts =3D of_find_node_with_property(parts, CONCAT_PROP); + if (!of_device_is_available(parts)) + continue; + + if (mtd_is_part_concat(parts)) + continue; + + count =3D of_count_phandle_with_args(parts, CONCAT_PROP, NULL); + if (count < MIN_DEV_PER_CONCAT) + continue; + + /* + * The partition in which "part-concat-next" property is defined + * is also part of the concat device, so increament count by 1. + */ + count++; + + ret =3D mtd_virt_concat_create_item(parts, count); + if (ret) { + of_node_put(parts); + goto destroy_items; + } + } while (parts); + + return ret; + +destroy_items: + mtd_virt_concat_destroy_items(); + + return ret; +} + +/** + * mtd_virt_concat_create_join - Create and register the concatenated + * MTD device. + * + * Return: 0 on success, -error otherwise. + */ +int mtd_virt_concat_create_join(void) +{ + struct mtd_virt_concat_node *item; + struct mtd_concat *concat; + struct mtd_info *mtd; + ssize_t name_sz; + int ret, idx; + char *name; + + list_for_each_entry(item, &concat_node_list, head) { + concat =3D item->concat; + /* + * Check if item->count !=3D concat->num_subdev, it indicates + * that the MTD information for all devices included in the + * concatenation are not handy, concat MTD device can't be + * created hence switch to next concat device. + */ + if (item->count !=3D concat->num_subdev) { + continue; + } else { + /* Calculate the legth of the name of the virtual device */ + for (idx =3D 0, name_sz =3D 0; idx < concat->num_subdev; idx++) + name_sz +=3D (strlen(concat->subdev[idx]->name) + 1); + name_sz +=3D strlen(CONCAT_POSTFIX); + name =3D kmalloc(name_sz + 1, GFP_KERNEL); + if (!name) { + mtd_virt_concat_put_mtd_devices(concat); + return -ENOMEM; + } + + ret =3D 0; + for (idx =3D 0; idx < concat->num_subdev; idx++) { + ret +=3D sprintf((name + ret), "%s-", + concat->subdev[idx]->name); + } + sprintf((name + ret), CONCAT_POSTFIX); + + if (concat->mtd.name) { + ret =3D memcmp(concat->mtd.name, name, name_sz); + if (ret =3D=3D 0) + continue; + } + mtd =3D mtd_concat_create(concat->subdev, concat->num_subdev, name); + if (!mtd) { + kfree(name); + return -ENXIO; + } + concat->mtd =3D *mtd; + /* Arbitrary set the first device as parent */ + concat->mtd.dev.parent =3D concat->subdev[0]->dev.parent; + concat->mtd.dev =3D concat->subdev[0]->dev; + + /* Add the mtd device */ + ret =3D add_mtd_device(&concat->mtd); + if (ret) + goto destroy_concat; + } + } + + return 0; + +destroy_concat: + mtd_concat_destroy(mtd); + + return ret; +} diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c index 64808493b4f5..576537774628 100644 --- a/drivers/mtd/mtdcore.c +++ b/drivers/mtd/mtdcore.c @@ -34,6 +34,7 @@ =20 #include #include +#include =20 #include "mtdcore.h" =20 @@ -1120,6 +1121,12 @@ int mtd_device_parse_register(struct mtd_info *mtd, = const char * const *types, goto out; } =20 + if (IS_REACHABLE(CONFIG_MTD_VIRT_CONCAT)) { + ret =3D mtd_virt_concat_node_create(); + if (ret < 0) + goto out; + } + /* Prefer parsed partitions over driver-provided fallback */ ret =3D parse_mtd_partitions(mtd, types, parser_data); if (ret =3D=3D -EPROBE_DEFER) @@ -1137,6 +1144,11 @@ int mtd_device_parse_register(struct mtd_info *mtd, = const char * const *types, if (ret) goto out; =20 + if (IS_REACHABLE(CONFIG_MTD_VIRT_CONCAT)) { + ret =3D mtd_virt_concat_create_join(); + if (ret < 0) + goto out; + } /* * FIXME: some drivers unfortunately call this function more than once. * So we have to check if we've already assigned the reboot notifier. @@ -1186,6 +1198,11 @@ int mtd_device_unregister(struct mtd_info *master) nvmem_unregister(master->otp_user_nvmem); nvmem_unregister(master->otp_factory_nvmem); =20 + if (IS_REACHABLE(CONFIG_MTD_VIRT_CONCAT)) { + err =3D mtd_virt_concat_destroy(master); + if (err) + return err; + } err =3D del_mtd_partitions(master); if (err) return err; @@ -2621,6 +2638,10 @@ static int __init init_mtd(void) =20 static void __exit cleanup_mtd(void) { + if (IS_REACHABLE(CONFIG_MTD_VIRT_CONCAT)) { + mtd_virt_concat_destroy_joins(); + mtd_virt_concat_destroy_items(); + } debugfs_remove_recursive(dfs_dir_mtd); cleanup_mtdchar(); if (proc_mtd) diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c index 2876501a7814..fc4483686242 100644 --- a/drivers/mtd/mtdpart.c +++ b/drivers/mtd/mtdpart.c @@ -18,6 +18,7 @@ #include #include #include +#include =20 #include "mtdcore.h" =20 @@ -409,6 +410,11 @@ int add_mtd_partitions(struct mtd_info *parent, goto err_del_partitions; } =20 + if (IS_REACHABLE(CONFIG_MTD_VIRT_CONCAT)) { + if (mtd_virt_concat_add(child)) + continue; + } + mutex_lock(&master->master.partitions_lock); list_add_tail(&child->part.node, &parent->partitions); mutex_unlock(&master->master.partitions_lock); diff --git a/include/linux/mtd/concat.h b/include/linux/mtd/concat.h index b42d9af87c4e..2cd9d48958a8 100644 --- a/include/linux/mtd/concat.h +++ b/include/linux/mtd/concat.h @@ -28,5 +28,54 @@ struct mtd_info *mtd_concat_create( =20 void mtd_concat_destroy(struct mtd_info *mtd); =20 -#endif +/** + * mtd_virt_concat_node_create - Create a component for concatenation + * + * Returns a positive number representing the no. of devices found for + * concatenation, or a negative error code. + * + * List all the devices for concatenations found in DT and create a + * component for concatenation. + */ +int mtd_virt_concat_node_create(void); + +/** + * mtd_virt_concat_add - add mtd_info object to the list of subdevices for= concatenation + * @mtd: pointer to new MTD device info structure + * + * Returns true if the mtd_info object is added successfully else returns = false. + * + * The mtd_info object is added to the list of subdevices for concatenatio= n. + * It returns true if a match is found, and false if all subdevices have + * already been added or if the mtd_info object does not match any of the + * intended MTD devices. + */ +bool mtd_virt_concat_add(struct mtd_info *mtd); =20 +/** + * mtd_virt_concat_create_join - Create and register the concatenated MTD = device + * + * Returns 0 on succes, or a negative error code. + * + * Creates and registers the concatenated MTD device + */ +int mtd_virt_concat_create_join(void); + +/** + * mtd_virt_concat_destroy - Remove the concat that includes a specific mt= d device + * as one of its components. + * @mtd: pointer to MTD device info structure. + * + * Returns 0 on succes, or a negative error code. + * + * If the mtd_info object is part of a concatenated device, all other MTD = devices + * within that concat are registered individually. The concatenated device= is then + * removed, along with its concatenation component. + * + */ +int mtd_virt_concat_destroy(struct mtd_info *mtd); + +void mtd_virt_concat_destroy_joins(void); +void mtd_virt_concat_destroy_items(void); + +#endif --=20 2.52.0