[PATCH v4 09/10] dt-bindings: firmware: add arm,ras-cper

Ahmed Tiba <[email protected]> Mon, 18 May 2026 12:57:52 +0100
Newsgroups dev.linux.lists.acpica-devel,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-acpi,org.kernel.vger.linux-cxl,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-doc,org.kernel.vger.linux-edac,org.kernel.vger.linux-kernel
Message-ID <20260518-topics-ahmtib01-ras_ffh_arm_internal_review-v4-9-42698675ba61@arm.com>
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 <[email protected]>
---
 .../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..81dc37390af5
--- /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 <[email protected]>
+
+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
+
+  memory-region:
+    oneOf:
+      - items:
+          - description:
+              CPER Generic Error Status block exposed by firmware
+      - items:
+          - description:
+              CPER Generic Error Status block exposed by firmware.
+          - description:
+              Optional firmware-owned ack buffer 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.
+
+required:
+  - compatible
+  - memory-region
+  - interrupts
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    reserved-memory {
+      #address-cells = <2>;
+      #size-cells = <2>;
+      ras_cper_buffer: memory@fe800000 {
+        reg = <0x0 0xfe800000 0x0 0x1000>;
+        no-map;
+      };
+
+      ras_cper_ack: memory@fe801000 {
+        reg = <0x0 0xfe801000 0x0 0x1000>;
+        no-map;
+      };
+    };
+
+    error-handler {
+      compatible = "arm,ras-cper";
+      memory-region = <&ras_cper_buffer>, <&ras_cper_ack>;
+      interrupts = <GIC_SPI 32 IRQ_TYPE_LEVEL_HIGH>;
+    };
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index 7492fefa447c..3bbc19589f1a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22251,6 +22251,11 @@ M:	Alexandre Bounine <[email protected]>
 S:	Maintained
 F:	drivers/rapidio/
 
+RAS ERROR STATUS
+M:	Ahmed Tiba <[email protected]>
+S:	Maintained
+F:	Documentation/devicetree/bindings/firmware/arm,ras-cper.yaml
+
 RAS INFRASTRUCTURE
 M:	Tony Luck <[email protected]>
 M:	Borislav Petkov <[email protected]>

-- 
2.43.0