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author | Russell King <rmk+kernel@arm.linux.org.uk> | 2015-07-07 12:35:33 +0100 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2015-07-07 12:35:33 +0100 |
commit | 06be5eefe1192eb8ce8d07497f67595b6bfe9741 (patch) | |
tree | 80f1987d4970f8079681f8be0c135cafc8d6329a /arch/tile/lib/spinlock_64.c | |
parent | ARM: fix lockdep unannotated irqs-off warning (diff) | |
parent | ARM: avoid unwanted GCC memset()/memcpy() optimisations for IO variants (diff) | |
download | linux-dev-06be5eefe1192eb8ce8d07497f67595b6bfe9741.tar.xz linux-dev-06be5eefe1192eb8ce8d07497f67595b6bfe9741.zip |
Merge branches 'fixes' and 'ioremap' into for-linus
Diffstat (limited to 'arch/tile/lib/spinlock_64.c')
-rw-r--r-- | arch/tile/lib/spinlock_64.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/arch/tile/lib/spinlock_64.c b/arch/tile/lib/spinlock_64.c index d6fb9581e980..c8d1f94ff1fe 100644 --- a/arch/tile/lib/spinlock_64.c +++ b/arch/tile/lib/spinlock_64.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)) + u32 val = READ_ONCE(lock->lock); + u32 curr = arch_spin_current(val); + + /* Return immediately if unlocked. */ + if (arch_spin_next(val) == curr) + return; + + /* Wait until the current locker has released the lock. */ + do { delay_backoff(iterations++); + } while (arch_spin_current(READ_ONCE(lock->lock)) == curr); } EXPORT_SYMBOL(arch_spin_unlock_wait); |