PSCI: Publish CPU ON event

This allows other EL3 components to subscribe to CPU on events.

Update Firmware Design guide to list psci_cpu_on_finish as an available
event.

Change-Id: Ida774afe0f9cdce4021933fcc33a9527ba7aaae2
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

docs/firmware-design.rst

@@ -2339,6 +2339,22 @@ implement:
 
    SUBSCRIBE_TO_EVENT(foo, foo_handler);
 
+Available Events
+~~~~~~~~~~~~~~~~
+
+ARM Trusted Firmware core makes some events available by default. They're listed
+below, along with information as to when they're published, and the arguments
+passed to subscribed handlers.
+
+Other EL3 components that are conditionally compiled in may make their own
+events available, but aren't documented here.
+
+-  ``psci_cpu_on_finish``
+
+   - When: Published on a PE after it's finished its power-up sequence.
+
+   - Argument: ``NULL``.
+
 Performance Measurement Framework
 ---------------------------------
 

include/lib/el3_runtime/pubsub_events.h

@@ -10,3 +10,9 @@
  * This file defines a list of pubsub events, declared using
  * REGISTER_PUBSUB_EVENT() macro.
  */
+
+/*
+ * Event published after a CPU has been powered up and finished its
+ * initialization.
+ */
+REGISTER_PUBSUB_EVENT(psci_cpu_on_finish);

lib/psci/psci_on.c

@@ -11,6 +11,7 @@
 #include <context_mgmt.h>
 #include <debug.h>
 #include <platform.h>
+#include <pubsub_events.h>
 #include <stddef.h>
 #include "psci_private.h"
 
@@ -188,6 +189,8 @@ void psci_cpu_on_finish(unsigned int cpu_idx,
 	if (psci_spd_pm && psci_spd_pm->svc_on_finish)
 		psci_spd_pm->svc_on_finish(0);
 
+	PUBLISH_EVENT(psci_cpu_on_finish);
+
 	/* Populate the mpidr field within the cpu node array */
 	/* This needs to be done only once */
 	psci_cpu_pd_nodes[cpu_idx].mpidr = read_mpidr() & MPIDR_AFFINITY_MASK;