[PATCH v2 10/11] dt-bindings: firmware: add arm,ras-ffh

Ahmed Tiba ahmed.tiba at arm.com
Fri Feb 20 05:42:28 PST 2026


Describe the DeviceTree node that exposes the Arm firmware-first handler
CPER provider and hook the file into MAINTAINERS so the binding has an
owner.

Signed-off-by: Ahmed Tiba <ahmed.tiba at arm.com>
---
 .../devicetree/bindings/firmware/arm,ras-ffh.yaml  | 71 ++++++++++++++++++++++
 MAINTAINERS                                        |  5 ++
 2 files changed, 76 insertions(+)

diff --git a/Documentation/devicetree/bindings/firmware/arm,ras-ffh.yaml b/Documentation/devicetree/bindings/firmware/arm,ras-ffh.yaml
new file mode 100644
index 000000000000..eccbaaf45885
--- /dev/null
+++ b/Documentation/devicetree/bindings/firmware/arm,ras-ffh.yaml
@@ -0,0 +1,71 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/firmware/arm,ras-ffh.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Arm Firmware-First Handler (FFH) CPER provider
+
+maintainers:
+  - Ahmed Tiba <ahmed.tiba at arm.com>
+
+description: |
+  Arm Reliability, Availability and Serviceability (RAS) firmware can expose
+  a firmware-first handler (FFH) that provides UEFI CPER Generic Error Status
+  blocks directly via DeviceTree. The firmware owns the CPER buffer
+  and notifies the OS through an interrupt.
+
+properties:
+  compatible:
+    const: arm,ras-ffh
+
+  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
+    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 <dt-bindings/interrupt-controller/arm-gic.h>
+
+    reserved-memory {
+      #address-cells = <2>;
+      #size-cells = <2>;
+      ras_cper_buffer: cper at fe800000 {
+        reg = <0x0 0xfe800000 0x0 0x1000>;
+        no-map;
+      };
+    };
+
+    error-handler at fe800000 {
+      compatible = "arm,ras-ffh";
+      reg = <0xfe800000 0x1000>,
+            <0xfe810000 0x4>;
+      memory-region = <&ras_cper_buffer>;
+      interrupts = <GIC_SPI 32 IRQ_TYPE_LEVEL_HIGH>;
+    };
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index b8d8a5c41597..47db7877b485 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22027,6 +22027,11 @@ M:	Alexandre Bounine <alex.bou9 at gmail.com>
 S:	Maintained
 F:	drivers/rapidio/
 
+RAS ERROR STATUS
+M:	Ahmed Tiba <ahmed.tiba at arm.com>
+S:	Maintained
+F:	Documentation/devicetree/bindings/firmware/arm,ras-ffh.yaml
+
 RAS INFRASTRUCTURE
 M:	Tony Luck <tony.luck at intel.com>
 M:	Borislav Petkov <bp at alien8.de>

-- 
2.43.0




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