# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
%YAML 1.2
---
$id: http://devicetree.org/schemas/reserved-memory/intel,wakeup-mailbox.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: Wakeup Mailbox for Intel processors

description: |
  The Wakeup Mailbox provides a mechanism for the operating system to wake up
  secondary CPUs on Intel processors. It is an alternative to the INIT-!INIT-
  SIPI sequence used on most x86 systems.

  The structure and operation of the mailbox is described in the Multiprocessor
  Wakeup Structure of the ACPI specification version 6.6 section 5.2.12.19 [1].

  The implementation of the mailbox in platform firmware is described in the
  Intel TDX Virtual Firmware Design Guide section 4.3.5 [2].

  1: https://uefi.org/specs/ACPI/6.6/05_ACPI_Software_Programming_Model.html#multiprocessor-wakeup-structure
  2: https://www.intel.com/content/www/us/en/content-details/733585/intel-tdx-virtual-firmware-design-guide.html

maintainers:
  - Ricardo Neri <ricardo.neri-calderon@linux.intel.com>

allOf:
  - $ref: reserved-memory.yaml

properties:
  compatible:
    const: intel,wakeup-mailbox

required:
  - compatible
  - reg

unevaluatedProperties: false

examples:
  - |
    reserved-memory {
        #address-cells = <2>;
        #size-cells = <1>;

        wakeup-mailbox@ffff0000 {
            compatible = "intel,wakeup-mailbox";
            reg = <0x0 0xffff0000 0x1000>;
        };
    };