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authorJonathan Corbet <corbet@lwn.net>2018-07-02 11:14:50 -0600
committerJonathan Corbet <corbet@lwn.net>2018-07-02 11:14:50 -0600
commit5f6654094ff35a7a92eb76667788ef633595e4ea (patch)
tree8404c5fb245cddbc6877b97a9bf53139c95da852 /lib/refcount.c
parent5105730fbf6789ff9e20837bdefe32e8ba133595 (diff)
parent021c91791a5e7e85c567452f1be3e4c2c6cb6063 (diff)
Merge tag 'v4.18-rc3' into docs-next
-rc1 broke the docs build due to changes in the e100/e1000 drivers; -rc3 got the fixes via the networking tree. Pull in -rc3 so that the docs tree can actually build the docs again.
Diffstat (limited to 'lib/refcount.c')
-rw-r--r--lib/refcount.c28
1 files changed, 28 insertions, 0 deletions
diff --git a/lib/refcount.c b/lib/refcount.c
index 0eb48353abe3..d3b81cefce91 100644
--- a/lib/refcount.c
+++ b/lib/refcount.c
@@ -350,3 +350,31 @@ bool refcount_dec_and_lock(refcount_t *r, spinlock_t *lock)
}
EXPORT_SYMBOL(refcount_dec_and_lock);
+/**
+ * refcount_dec_and_lock_irqsave - return holding spinlock with disabled
+ * interrupts if able to decrement refcount to 0
+ * @r: the refcount
+ * @lock: the spinlock to be locked
+ * @flags: saved IRQ-flags if the is acquired
+ *
+ * Same as refcount_dec_and_lock() above except that the spinlock is acquired
+ * with disabled interupts.
+ *
+ * Return: true and hold spinlock if able to decrement refcount to 0, false
+ * otherwise
+ */
+bool refcount_dec_and_lock_irqsave(refcount_t *r, spinlock_t *lock,
+ unsigned long *flags)
+{
+ if (refcount_dec_not_one(r))
+ return false;
+
+ spin_lock_irqsave(lock, *flags);
+ if (!refcount_dec_and_test(r)) {
+ spin_unlock_irqrestore(lock, *flags);
+ return false;
+ }
+
+ return true;
+}
+EXPORT_SYMBOL(refcount_dec_and_lock_irqsave);