diff options
| -rw-r--r-- | lib/locks/bakery/bakery_lock_coherent.c | 15 | ||||
| -rw-r--r-- | lib/locks/bakery/bakery_lock_normal.c | 13 |
2 files changed, 23 insertions, 5 deletions
diff --git a/lib/locks/bakery/bakery_lock_coherent.c b/lib/locks/bakery/bakery_lock_coherent.c index 788ba981..03277c32 100644 --- a/lib/locks/bakery/bakery_lock_coherent.c +++ b/lib/locks/bakery/bakery_lock_coherent.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2013-2015, ARM Limited and Contributors. All rights reserved. + * Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved. * * SPDX-License-Identifier: BSD-3-Clause */ @@ -133,7 +133,12 @@ void bakery_lock_get(bakery_lock_t *bakery) bakery_ticket_number(bakery->lock_data[they])); } } - /* Lock acquired */ + + /* + * Lock acquired. Ensure that any reads from a shared resource in the + * critical section read values after the lock is acquired. + */ + dmbld(); } @@ -146,9 +151,11 @@ void bakery_lock_release(bakery_lock_t *bakery) assert(bakery_ticket_number(bakery->lock_data[me])); /* - * Release lock by resetting ticket. Then signal other - * waiting contenders + * Ensure that other observers see any stores in the critical section + * before releasing the lock. Release the lock by resetting ticket. + * Then signal other waiting contenders. */ + dmbst(); bakery->lock_data[me] = 0; dsb(); sev(); diff --git a/lib/locks/bakery/bakery_lock_normal.c b/lib/locks/bakery/bakery_lock_normal.c index 630226ae..b947da9c 100644 --- a/lib/locks/bakery/bakery_lock_normal.c +++ b/lib/locks/bakery/bakery_lock_normal.c @@ -204,7 +204,12 @@ void bakery_lock_get(bakery_lock_t *lock) == bakery_ticket_number(their_bakery_info->lock_data)); } } - /* Lock acquired */ + + /* + * Lock acquired. Ensure that any reads from a shared resource in the + * critical section read values after the lock is acquired. + */ + dmbld(); } void bakery_lock_release(bakery_lock_t *lock) @@ -220,6 +225,12 @@ void bakery_lock_release(bakery_lock_t *lock) assert(is_lock_acquired(my_bakery_info, is_cached)); + /* + * Ensure that other observers see any stores in the critical section + * before releasing the lock. Release the lock by resetting ticket. + * Then signal other waiting contenders. + */ + dmbst(); my_bakery_info->lock_data = 0; write_cache_op(my_bakery_info, is_cached); sev(); |