tree 39d20b7fa667cb25499839fba56cfe69afcc1fe7
parent fd7c7978cfee3138a645a2014b02562f94aef141
author Madhukar Pappireddy <madhukar.pappireddy@arm.com> 1593843830 -0500
committer Madhukar Pappireddy <madhukar.pappireddy@arm.com> 1593844058 -0500

Add explicit barrier before sev() in tftf_send_event_common API

Consider the following scenario: If sev() gets reordered above the
event->cnt+=inc operation in tftf_send_event_common() on core 0, and lets
say core 1 is in wfe in tftf_wait_for_event, core 1 receives the event
before the write to event->cnt from core 0 propagates to core 1. Later,
core 1 wakes up, reads event->cnt, sees that it is 0 and goes back to
wfe, thereby leading to hang.

Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>
Change-Id: I2e8a5ab7c220b02d5b637dc7cdf3562ca73dbfdc