diff options
Diffstat (limited to 'lib/locks/bakery/bakery_lock_coherent.c')
| -rw-r--r-- | lib/locks/bakery/bakery_lock_coherent.c | 80 |
1 files changed, 20 insertions, 60 deletions
diff --git a/lib/locks/bakery/bakery_lock_coherent.c b/lib/locks/bakery/bakery_lock_coherent.c index 5d538ce2..a857e035 100644 --- a/lib/locks/bakery/bakery_lock_coherent.c +++ b/lib/locks/bakery/bakery_lock_coherent.c @@ -1,31 +1,7 @@ /* - * Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved. + * Copyright (c) 2013-2015, ARM Limited and Contributors. All rights reserved. * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions are met: - * - * Redistributions of source code must retain the above copyright notice, this - * list of conditions and the following disclaimer. - * - * Redistributions in binary form must reproduce the above copyright notice, - * this list of conditions and the following disclaimer in the documentation - * and/or other materials provided with the distribution. - * - * Neither the name of ARM nor the names of its contributors may be used - * to endorse or promote products derived from this software without specific - * prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" - * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE - * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR - * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF - * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS - * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN - * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) - * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE - * POSSIBILITY OF SUCH DAMAGE. + * SPDX-License-Identifier: BSD-3-Clause */ #include <arch_helpers.h> @@ -63,27 +39,15 @@ assert(entry < BAKERY_LOCK_MAX_CPUS); \ } while (0) -/* Convert a ticket to priority */ -#define PRIORITY(t, pos) (((t) << 8) | (pos)) - - -/* Initialize Bakery Lock to reset ownership and all ticket values */ -void bakery_lock_init(bakery_lock_t *bakery) -{ - assert(bakery); - - /* All ticket values need to be 0 */ - memset(bakery, 0, sizeof(*bakery)); - bakery->owner = NO_OWNER; -} - - /* Obtain a ticket for a given CPU */ static unsigned int bakery_get_ticket(bakery_lock_t *bakery, unsigned int me) { unsigned int my_ticket, their_ticket; unsigned int they; + /* Prevent recursive acquisition */ + assert(!bakery_ticket_number(bakery->lock_data[me])); + /* * Flag that we're busy getting our ticket. All CPUs are iterated in the * order of their ordinal position to decide the maximum ticket value @@ -95,9 +59,9 @@ static unsigned int bakery_get_ticket(bakery_lock_t *bakery, unsigned int me) * value, not the ticket value alone. */ my_ticket = 0; - bakery->entering[me] = 1; + bakery->lock_data[me] = make_bakery_data(CHOOSING_TICKET, my_ticket); for (they = 0; they < BAKERY_LOCK_MAX_CPUS; they++) { - their_ticket = bakery->number[they]; + their_ticket = bakery_ticket_number(bakery->lock_data[they]); if (their_ticket > my_ticket) my_ticket = their_ticket; } @@ -107,8 +71,7 @@ static unsigned int bakery_get_ticket(bakery_lock_t *bakery, unsigned int me) * finish calculating our ticket value that we're done */ ++my_ticket; - bakery->number[me] = my_ticket; - bakery->entering[me] = 0; + bakery->lock_data[me] = make_bakery_data(CHOSEN_TICKET, my_ticket); return my_ticket; } @@ -129,14 +92,12 @@ void bakery_lock_get(bakery_lock_t *bakery) { unsigned int they, me; unsigned int my_ticket, my_prio, their_ticket; + unsigned int their_bakery_data; - me = platform_get_core_pos(read_mpidr_el1()); + me = plat_my_core_pos(); assert_bakery_entry_valid(me, bakery); - /* Prevent recursive acquisition */ - assert(bakery->owner != me); - /* Get a ticket */ my_ticket = bakery_get_ticket(bakery, me); @@ -150,14 +111,15 @@ void bakery_lock_get(bakery_lock_t *bakery) continue; /* Wait for the contender to get their ticket */ - while (bakery->entering[they]) - ; + do { + their_bakery_data = bakery->lock_data[they]; + } while (bakery_is_choosing(their_bakery_data)); /* * If the other party is a contender, they'll have non-zero * (valid) ticket value. If they do, compare priorities */ - their_ticket = bakery->number[they]; + their_ticket = bakery_ticket_number(their_bakery_data); if (their_ticket && (PRIORITY(their_ticket, they) < my_prio)) { /* * They have higher priority (lower value). Wait for @@ -167,29 +129,27 @@ void bakery_lock_get(bakery_lock_t *bakery) */ do { wfe(); - } while (their_ticket == bakery->number[they]); + } while (their_ticket == + bakery_ticket_number(bakery->lock_data[they])); } } - /* Lock acquired */ - bakery->owner = me; } /* Release the lock and signal contenders */ void bakery_lock_release(bakery_lock_t *bakery) { - unsigned int me = platform_get_core_pos(read_mpidr_el1()); + unsigned int me = plat_my_core_pos(); assert_bakery_entry_valid(me, bakery); - assert(bakery->owner == me); + assert(bakery_ticket_number(bakery->lock_data[me])); /* - * Release lock by resetting ownership and ticket. Then signal other + * Release lock by resetting ticket. Then signal other * waiting contenders */ - bakery->owner = NO_OWNER; - bakery->number[me] = 0; + bakery->lock_data[me] = 0; dsb(); sev(); } |