Optimize the bakery lock structure for coherent memory
This patch optimizes the data structure used with the bakery lock
implementation for coherent memory to save memory and minimize memory
accesses. These optimizations were already part of the bakery lock
implementation for normal memory and this patch now implements
it for the coherent memory implementation as well. Also
included in the patch is a cleanup to use the do-while loop while
waiting for other contenders to finish choosing their tickets.
Change-Id: Iedb305473133dc8f12126726d8329b67888b70f1
diff --git a/lib/locks/bakery/bakery_lock_normal.c b/lib/locks/bakery/bakery_lock_normal.c
index a325fd4..4503ae0 100644
--- a/lib/locks/bakery/bakery_lock_normal.c
+++ b/lib/locks/bakery/bakery_lock_normal.c
@@ -56,17 +56,6 @@
* accesses regardless of status of address translation.
*/
-/* Convert a ticket to priority */
-#define PRIORITY(t, pos) (((t) << 8) | (pos))
-
-#define CHOOSING_TICKET 0x1
-#define CHOOSING_DONE 0x0
-
-#define bakery_is_choosing(info) (info & 0x1)
-#define bakery_ticket_number(info) ((info >> 1) & 0x7FFF)
-#define make_bakery_data(choosing, number) \
- (((choosing & 0x1) | (number << 1)) & 0xFFFF)
-
/* This macro assumes that the bakery_info array is located at the offset specified */
#define get_my_bakery_info(offset, id) \
(((bakery_info_t *) (((uint8_t *)_cpu_data()) + offset)) + id)
@@ -138,7 +127,7 @@
* finish calculating our ticket value that we're done
*/
++my_ticket;
- my_bakery_info->lock_data = make_bakery_data(CHOOSING_DONE, my_ticket);
+ my_bakery_info->lock_data = make_bakery_data(CHOSEN_TICKET, my_ticket);
write_cache_op(my_bakery_info, is_cached);
@@ -150,7 +139,7 @@
unsigned int they, me, is_cached;
unsigned int my_ticket, my_prio, their_ticket;
bakery_info_t *their_bakery_info;
- uint16_t their_bakery_data;
+ unsigned int their_bakery_data;
me = platform_get_core_pos(read_mpidr_el1());
@@ -174,15 +163,12 @@
*/
their_bakery_info = get_bakery_info_by_index(offset, id, they);
assert(their_bakery_info);
- read_cache_op(their_bakery_info, is_cached);
-
- their_bakery_data = their_bakery_info->lock_data;
/* Wait for the contender to get their ticket */
- while (bakery_is_choosing(their_bakery_data)) {
+ do {
read_cache_op(their_bakery_info, is_cached);
their_bakery_data = their_bakery_info->lock_data;
- }
+ } while (bakery_is_choosing(their_bakery_data));
/*
* If the other party is a contender, they'll have non-zero