Precede a 'sev' with a 'dsb' in bakery lock code

This patch fixes a bug in the bakery lock implementation where a data
synchronisation barrier instruction is not issued before sending an event as
mandated by the ARMv8 ARM. This can cause a event to be signalled before the
related memory accesses have completed resulting in erroneous execution.

Fixes ARM-software/tf-issues#272

Change-Id: I5ce02bf70afb001d967b9fa4c3f77442931d5349
This commit is contained in:
Achin Gupta 2014-11-10 11:50:30 +00:00
parent 82b9b2973b
commit 66ce001e7d
1 changed files with 2 additions and 0 deletions

View File

@ -107,6 +107,7 @@ static unsigned int bakery_get_ticket(bakery_lock_t *bakery, unsigned int me)
++my_ticket;
bakery->number[me] = my_ticket;
bakery->entering[me] = 0;
dsb();
sev();
return my_ticket;
@ -189,5 +190,6 @@ void bakery_lock_release(bakery_lock_t *bakery)
*/
bakery->owner = NO_OWNER;
bakery->number[me] = 0;
dsb();
sev();
}