X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Farch%2Ftile%2Finclude%2Fasm%2Fspinlock_32.h;h=b14b1ba5bf9c328959bea3a14643fbb87e4ae7b1;hb=e09b41010ba33a20a87472ee821fa407a5b8da36;hp=c0a77b38d39a73c8b7064b4b92a340a92b7f83e8;hpb=f93b97fd65072de626c074dbe099a1fff05ce060;p=kvmfornfv.git

diff --git a/kernel/arch/tile/include/asm/spinlock_32.h b/kernel/arch/tile/include/asm/spinlock_32.h
index c0a77b38d..b14b1ba5b 100644
--- a/kernel/arch/tile/include/asm/spinlock_32.h
+++ b/kernel/arch/tile/include/asm/spinlock_32.h
@@ -41,8 +41,12 @@ static inline int arch_spin_is_locked(arch_spinlock_t *lock)
 	 * to claim the lock is held, since it will be momentarily
 	 * if not already.  There's no need to wait for a "valid"
 	 * lock->next_ticket to become available.
+	 * Use READ_ONCE() to ensure that calling this in a loop is OK.
 	 */
-	return lock->next_ticket != lock->current_ticket;
+	int curr = READ_ONCE(lock->current_ticket);
+	int next = READ_ONCE(lock->next_ticket);
+
+	return next != curr;
 }
 
 void arch_spin_lock(arch_spinlock_t *lock);