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-rw-r--r--lib/dec_and_lock.c31
1 files changed, 31 insertions, 0 deletions
diff --git a/lib/dec_and_lock.c b/lib/dec_and_lock.c
index 9555b68bb774..1dcca8f2e194 100644
--- a/lib/dec_and_lock.c
+++ b/lib/dec_and_lock.c
@@ -49,3 +49,34 @@ int _atomic_dec_and_lock_irqsave(atomic_t *atomic, spinlock_t *lock,
return 0;
}
EXPORT_SYMBOL(_atomic_dec_and_lock_irqsave);
+
+int _atomic_dec_and_raw_lock(atomic_t *atomic, raw_spinlock_t *lock)
+{
+ /* Subtract 1 from counter unless that drops it to 0 (ie. it was 1) */
+ if (atomic_add_unless(atomic, -1, 1))
+ return 0;
+
+ /* Otherwise do it the slow way */
+ raw_spin_lock(lock);
+ if (atomic_dec_and_test(atomic))
+ return 1;
+ raw_spin_unlock(lock);
+ return 0;
+}
+EXPORT_SYMBOL(_atomic_dec_and_raw_lock);
+
+int _atomic_dec_and_raw_lock_irqsave(atomic_t *atomic, raw_spinlock_t *lock,
+ unsigned long *flags)
+{
+ /* Subtract 1 from counter unless that drops it to 0 (ie. it was 1) */
+ if (atomic_add_unless(atomic, -1, 1))
+ return 0;
+
+ /* Otherwise do it the slow way */
+ raw_spin_lock_irqsave(lock, *flags);
+ if (atomic_dec_and_test(atomic))
+ return 1;
+ raw_spin_unlock_irqrestore(lock, *flags);
+ return 0;
+}
+EXPORT_SYMBOL(_atomic_dec_and_raw_lock_irqsave);