summaryrefslogtreecommitdiffstats
path: root/lib/refcount.c
diff options
context:
space:
mode:
authorThomas Gleixner <tglx@linutronix.de>2018-07-12 22:19:58 +0200
committerThomas Gleixner <tglx@linutronix.de>2018-07-12 22:19:58 +0200
commitc6bb11147eb09bd39f316c6062455b88c905ab6e (patch)
tree5a1a6ec2970daef5fa8546741ced3ef3924bf807 /lib/refcount.c
parenta8802d97e73346bc81609df9dfba7d3306f40d87 (diff)
parentb061c7a513afe14a68af41cec7c3476befc40e95 (diff)
downloadlinux-c6bb11147eb09bd39f316c6062455b88c905ab6e.tar.bz2
Merge branch 'fortglx/4.19/time' of https://git.linaro.org/people/john.stultz/linux into timers/core
Pull timekeeping updates from John Stultz: - Make the timekeeping update more precise when NTP frequency is set directly by updating the multiplier. - Adjust selftests
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);