/'
 ' Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
 '
 ' SPDX-License-Identifier: BSD-3-Clause
 '/

@startuml

autonumber "<b>[#]</b>"
participant "SDEI client" as EL2
participant EL3
participant SDEI
participant "RAS Driver" as RAS

activate EL2
EL2->EL3: **SDEI_EVENT_REGISTER**(ev, handler, ...)
EL3->EL2: success
EL2->EL3: **SDEI_EVENT_ENABLE**(ev)
EL3->EL2: success
EL2->EL3: **SDEI_PE_UNMASK**()
EL3->EL2: 1

... <<Business as usual>> ...

EL3<--]: **CRITICAL EVENT**
activate EL3 #red
note over EL3: Critical event triage
EL3->RAS: dispatch to handle
deactivate EL3
activate RAS #salmon
note over RAS: Critical event handling
RAS-->SDEI: sdei_dispatch_event(ev)
deactivate RAS
activate SDEI #salmon
note over SDEI: Prepare SDEI dispatch
SDEI->EL2: dispatch
activate EL2 #salmon
note over EL2: SDEI handler
EL2->SDEI: **SDEI_EVENT_COMPLETE()**
deactivate EL2
note over SDEI: Complete SDEI dispatch
SDEI-->RAS: return
deactivate SDEI
activate RAS #salmon
RAS->EL3: error handling done
deactivate RAS
EL3->EL2: resumes preempted execution

... <<Normal execution resumes>> ...

@enduml