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Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1w5mZn-00000005kGo-06FK; Thu, 26 Mar 2026 15:24:51 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1w5mZc-00000005kEL-42h7 for linux-arm-kernel@lists.infradead.org; Thu, 26 Mar 2026 15:24:44 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 3865443830; Thu, 26 Mar 2026 15:24:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D8768C19423; Thu, 26 Mar 2026 15:24:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774538680; bh=VC8lDUeLQaF89olSSrKq5JgPweNUCYlwAaUQYICMSVc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=kaAEnN52eATLIBzXKxWYkAjEQF54lvKDkYc4MOirqFrd5bD5DAIMQRi7Z6XFDonBb WKa61FlMkBcd/iXQJ6NVvj56BLrUfSeujVI4srqkrjEo0YNkS+P6/Xr/rSzIa4TTE8 2nnxiSlLoWZ9fwxqX9ylNk7h2LFe47bb/mfRrR6P0j9DmK3EzFipJ7bxp5c8xm2TuS NiMdnWVRBzuXH1POPXiMkAnG50ifQBOXsOongqLa/bTPgKB4QNBbt70yCIYs0d7SRq J1Ih9mzFlDLWUDBMRSL14ekNbotN/3lElMlAvI5lwEmHOwIOUc4QCgy+qNYqG3bT9G pKTZSBiYPPjOg== Date: Thu, 26 Mar 2026 10:24:36 -0500 From: Rob Herring To: Ahmed Tiba Cc: linux-acpi@vger.kernel.org, devicetree@vger.kernel.org, linux-cxl@vger.kernel.org, Michael.Zhao2@arm.com, linux-arm-kernel@lists.infradead.org, Dmitry.Lamerov@arm.com, rafael@kernel.org, conor@kernel.org, will@kernel.org, bp@alien8.de, catalin.marinas@arm.com, krzk+dt@kernel.org, linux-doc@vger.kernel.org, mchehab+huawei@kernel.org, tony.luck@intel.com Subject: Re: [PATCH v3 09/10] dt-bindings: firmware: add arm,ras-cper Message-ID: <20260326152436.GA2484010-robh@kernel.org> References: <20260318-topics-ahmtib01-ras_ffh_arm_internal_review-v3-0-48e6a1c249ef@arm.com> <20260318-topics-ahmtib01-ras_ffh_arm_internal_review-v3-9-48e6a1c249ef@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260318-topics-ahmtib01-ras_ffh_arm_internal_review-v3-9-48e6a1c249ef@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260326_082441_056350_895070B3 X-CRM114-Status: GOOD ( 21.03 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Mar 18, 2026 at 08:48:06PM +0000, Ahmed Tiba wrote: > Describe the DeviceTree node that exposes the Arm firmware-first > CPER provider and hook the file into MAINTAINERS so the > binding has an owner. > > Signed-off-by: Ahmed Tiba > --- > .../devicetree/bindings/firmware/arm,ras-cper.yaml | 71 ++++++++++++++++++++++ > MAINTAINERS | 5 ++ > 2 files changed, 76 insertions(+) > > diff --git a/Documentation/devicetree/bindings/firmware/arm,ras-cper.yaml b/Documentation/devicetree/bindings/firmware/arm,ras-cper.yaml > new file mode 100644 > index 000000000000..bd93cfb8d222 > --- /dev/null > +++ b/Documentation/devicetree/bindings/firmware/arm,ras-cper.yaml > @@ -0,0 +1,71 @@ > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/firmware/arm,ras-cper.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: Arm RAS CPER provider > + > +maintainers: > + - Ahmed Tiba > + > +description: | > + Arm Reliability, Availability and Serviceability (RAS) firmware can expose > + a firmware-first CPER error source directly via DeviceTree. Firmware > + provides the CPER Generic Error Status block and notifies the OS through > + an interrupt. > + > +properties: > + compatible: > + const: arm,ras-cper > + > + reg: > + minItems: 1 > + items: > + - description: > + CPER Generic Error Status block exposed by firmware > + - description: > + Optional 32- or 64-bit doorbell register used on platforms > + where firmware needs an explicit "ack" handshake before overwriting > + the CPER buffer. Firmware watches bit 0 and expects the OS to set it > + once the current status block has been consumed. > + > + interrupts: > + maxItems: 1 > + description: > + Interrupt used to signal that a new status record is ready. > + > + memory-region: > + $ref: /schemas/types.yaml#/definitions/phandle memory-region already has a defined type. You just need to define how many entries (maxItems: 1). > + description: > + Optional phandle to the reserved-memory entry that backs the status > + buffer so firmware and the OS use the same carved-out region. > + > +required: > + - compatible > + - reg > + - interrupts > + > +additionalProperties: false > + > +examples: > + - | > + #include > + > + reserved-memory { > + #address-cells = <2>; > + #size-cells = <2>; > + ras_cper_buffer: cper@fe800000 { > + reg = <0x0 0xfe800000 0x0 0x1000>; > + no-map; > + }; > + }; > + > + error-handler@fe800000 { > + compatible = "arm,ras-cper"; > + reg = <0xfe800000 0x1000>, Wait! Why is the reserved address here? There's 2 problems with that. There shouldn't be same address in 2 places in the DT. The 2nd is reserved memory should only be regions within DRAM (or whatever is system memory). Rob