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/*
* Copyright (c) 2018, Arm Limited. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <arch_helpers.h>
#include <assert.h>
#include <debug.h>
#include <events.h>
#include <platform_def.h>
#include <tftf.h>
#include <tftf_lib.h>
void tftf_init_event(event_t *event)
{
assert(event != NULL);
event->cnt = 0;
event->lock.lock = 0;
}
static void send_event_common(event_t *event, unsigned int inc)
{
spin_lock(&event->lock);
event->cnt += inc;
spin_unlock(&event->lock);
sev();
}
void tftf_send_event(event_t *event)
{
VERBOSE("Sending event %p\n", (void *) event);
send_event_common(event, 1);
}
void tftf_send_event_to_all(event_t *event)
{
VERBOSE("Sending event %p to all CPUs\n", (void *) event);
send_event_common(event, PLATFORM_CORE_COUNT);
}
void tftf_send_event_to(event_t *event, unsigned int cpus_count)
{
assert(cpus_count <= PLATFORM_CORE_COUNT);
VERBOSE("Sending event %p to %u CPUs\n", (void *) event, cpus_count);
send_event_common(event, cpus_count);
}
void tftf_wait_for_event(event_t *event)
{
unsigned int event_received = 0;
VERBOSE("Waiting for event %p\n", (void *) event);
while (!event_received) {
dsbsy();
/* Wait for someone to send an event */
if (!event->cnt) {
wfe();
} else {
spin_lock(&event->lock);
/*
* Check that the event is still pending and that no
* one stole it from us while we were trying to
* acquire the lock.
*/
if (event->cnt != 0) {
event_received = 1;
--event->cnt;
}
/*
* No memory barrier is needed here because spin_unlock()
* issues a Store-Release instruction, which guarantees
* that loads and stores appearing in program order
* before the Store-Release are observed before the
* Store-Release itself.
*/
spin_unlock(&event->lock);
}
}
VERBOSE("Received event %p\n", (void *) event);
}
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