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authorJosé Pekkarinen <jose.pekkarinen@nokia.com>2016-04-11 10:41:07 +0300
committerJosé Pekkarinen <jose.pekkarinen@nokia.com>2016-04-13 08:17:18 +0300
commite09b41010ba33a20a87472ee821fa407a5b8da36 (patch)
treed10dc367189862e7ca5c592f033dc3726e1df4e3 /kernel/arch/tile/lib/spinlock_32.c
parentf93b97fd65072de626c074dbe099a1fff05ce060 (diff)
These changes are the raw update to linux-4.4.6-rt14. Kernel sources
are taken from kernel.org, and rt patch from the rt wiki download page. During the rebasing, the following patch collided: Force tick interrupt and get rid of softirq magic(I70131fb85). Collisions have been removed because its logic was found on the source already. Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769 Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>
Diffstat (limited to 'kernel/arch/tile/lib/spinlock_32.c')
-rw-r--r--kernel/arch/tile/lib/spinlock_32.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/kernel/arch/tile/lib/spinlock_32.c b/kernel/arch/tile/lib/spinlock_32.c
index b34f79aad..88c2a5336 100644
--- a/kernel/arch/tile/lib/spinlock_32.c
+++ b/kernel/arch/tile/lib/spinlock_32.c
@@ -65,8 +65,17 @@ EXPORT_SYMBOL(arch_spin_trylock);
void arch_spin_unlock_wait(arch_spinlock_t *lock)
{
u32 iterations = 0;
- while (arch_spin_is_locked(lock))
+ int curr = READ_ONCE(lock->current_ticket);
+ int next = READ_ONCE(lock->next_ticket);
+
+ /* Return immediately if unlocked. */
+ if (next == curr)
+ return;
+
+ /* Wait until the current locker has released the lock. */
+ do {
delay_backoff(iterations++);
+ } while (READ_ONCE(lock->current_ticket) == curr);
}
EXPORT_SYMBOL(arch_spin_unlock_wait);