GIC: Introduce API to get interrupt ID
Acknowledging interrupt shall return a raw value from the interrupt
controller in which the actual interrupt ID may be encoded. Add a
platform API to extract the actual interrupt ID from the raw value
obtained from interrupt controller.
Document the new function. Also clarify the semantics of interrupt
acknowledge.
Change-Id: I818dad7be47661658b16f9807877d259eb127405
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
diff --git a/docs/platform-interrupt-controller-API.rst b/docs/platform-interrupt-controller-API.rst
index 795c085..c14f005 100644
--- a/docs/platform-interrupt-controller-API.rst
+++ b/docs/platform-interrupt-controller-API.rst
@@ -292,6 +292,22 @@
*Priority Mask Register*, and make sure memory updates are visible before
potential trigger due to mask update.
+Function: unsigned int plat_ic_get_interrupt_id(unsigned int raw); [optional]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+::
+
+ Argument : unsigned int
+ Return : unsigned int
+
+This API should extract and return the interrupt number from the raw value
+obtained by the acknowledging the interrupt (read using
+``plat_ic_acknowledge_interrupt()``). If the interrupt ID is invalid, this API
+should return ``INTR_ID_UNAVAILABLE``.
+
+In case of ARM standard platforms using GIC, the implementation of the API
+masks out the interrupt ID field from the acknowledged value from GIC.
+
----
*Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.*